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4673 lines
125 KiB
4673 lines
125 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* drivers/base/core.c - core driver model code (device registration, etc) |
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* |
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* Copyright (c) 2002-3 Patrick Mochel |
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* Copyright (c) 2002-3 Open Source Development Labs |
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* Copyright (c) 2006 Greg Kroah-Hartman <[email protected]> |
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* Copyright (c) 2006 Novell, Inc. |
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*/ |
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|
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#include <linux/acpi.h> |
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#include <linux/cpufreq.h> |
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#include <linux/device.h> |
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#include <linux/err.h> |
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#include <linux/fwnode.h> |
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#include <linux/init.h> |
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#include <linux/module.h> |
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#include <linux/slab.h> |
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#include <linux/string.h> |
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#include <linux/kdev_t.h> |
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#include <linux/notifier.h> |
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#include <linux/of.h> |
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#include <linux/of_device.h> |
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#include <linux/genhd.h> |
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#include <linux/mutex.h> |
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#include <linux/pm_runtime.h> |
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#include <linux/netdevice.h> |
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#include <linux/sched/signal.h> |
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#include <linux/sched/mm.h> |
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#include <linux/sysfs.h> |
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#include <linux/dma-map-ops.h> /* for dma_default_coherent */ |
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|
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#include "base.h" |
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#include "power/power.h" |
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|
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#ifdef CONFIG_SYSFS_DEPRECATED |
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#ifdef CONFIG_SYSFS_DEPRECATED_V2 |
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long sysfs_deprecated = 1; |
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#else |
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long sysfs_deprecated = 0; |
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#endif |
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static int __init sysfs_deprecated_setup(char *arg) |
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{ |
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return kstrtol(arg, 10, &sysfs_deprecated); |
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} |
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early_param("sysfs.deprecated", sysfs_deprecated_setup); |
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#endif |
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|
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/* Device links support. */ |
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static LIST_HEAD(deferred_sync); |
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static unsigned int defer_sync_state_count = 1; |
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static DEFINE_MUTEX(fwnode_link_lock); |
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static bool fw_devlink_is_permissive(void); |
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|
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/** |
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* fwnode_link_add - Create a link between two fwnode_handles. |
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* @con: Consumer end of the link. |
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* @sup: Supplier end of the link. |
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* |
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* Create a fwnode link between fwnode handles @con and @sup. The fwnode link |
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* represents the detail that the firmware lists @sup fwnode as supplying a |
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* resource to @con. |
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* |
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* The driver core will use the fwnode link to create a device link between the |
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* two device objects corresponding to @con and @sup when they are created. The |
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* driver core will automatically delete the fwnode link between @con and @sup |
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* after doing that. |
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* |
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* Attempts to create duplicate links between the same pair of fwnode handles |
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* are ignored and there is no reference counting. |
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*/ |
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int fwnode_link_add(struct fwnode_handle *con, struct fwnode_handle *sup) |
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{ |
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struct fwnode_link *link; |
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int ret = 0; |
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|
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mutex_lock(&fwnode_link_lock); |
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|
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list_for_each_entry(link, &sup->consumers, s_hook) |
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if (link->consumer == con) |
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goto out; |
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|
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link = kzalloc(sizeof(*link), GFP_KERNEL); |
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if (!link) { |
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ret = -ENOMEM; |
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goto out; |
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} |
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|
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link->supplier = sup; |
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INIT_LIST_HEAD(&link->s_hook); |
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link->consumer = con; |
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INIT_LIST_HEAD(&link->c_hook); |
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|
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list_add(&link->s_hook, &sup->consumers); |
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list_add(&link->c_hook, &con->suppliers); |
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out: |
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mutex_unlock(&fwnode_link_lock); |
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|
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return ret; |
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} |
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|
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/** |
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* fwnode_links_purge_suppliers - Delete all supplier links of fwnode_handle. |
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* @fwnode: fwnode whose supplier links need to be deleted |
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* |
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* Deletes all supplier links connecting directly to @fwnode. |
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*/ |
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static void fwnode_links_purge_suppliers(struct fwnode_handle *fwnode) |
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{ |
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struct fwnode_link *link, *tmp; |
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|
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mutex_lock(&fwnode_link_lock); |
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list_for_each_entry_safe(link, tmp, &fwnode->suppliers, c_hook) { |
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list_del(&link->s_hook); |
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list_del(&link->c_hook); |
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kfree(link); |
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} |
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mutex_unlock(&fwnode_link_lock); |
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} |
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|
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/** |
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* fwnode_links_purge_consumers - Delete all consumer links of fwnode_handle. |
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* @fwnode: fwnode whose consumer links need to be deleted |
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* |
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* Deletes all consumer links connecting directly to @fwnode. |
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*/ |
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static void fwnode_links_purge_consumers(struct fwnode_handle *fwnode) |
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{ |
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struct fwnode_link *link, *tmp; |
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|
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mutex_lock(&fwnode_link_lock); |
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list_for_each_entry_safe(link, tmp, &fwnode->consumers, s_hook) { |
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list_del(&link->s_hook); |
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list_del(&link->c_hook); |
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kfree(link); |
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} |
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mutex_unlock(&fwnode_link_lock); |
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} |
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|
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/** |
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* fwnode_links_purge - Delete all links connected to a fwnode_handle. |
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* @fwnode: fwnode whose links needs to be deleted |
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* |
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* Deletes all links connecting directly to a fwnode. |
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*/ |
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void fwnode_links_purge(struct fwnode_handle *fwnode) |
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{ |
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fwnode_links_purge_suppliers(fwnode); |
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fwnode_links_purge_consumers(fwnode); |
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} |
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|
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static void fw_devlink_purge_absent_suppliers(struct fwnode_handle *fwnode) |
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{ |
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struct fwnode_handle *child; |
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|
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/* Don't purge consumer links of an added child */ |
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if (fwnode->dev) |
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return; |
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|
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fwnode->flags |= FWNODE_FLAG_NOT_DEVICE; |
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fwnode_links_purge_consumers(fwnode); |
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|
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fwnode_for_each_available_child_node(fwnode, child) |
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fw_devlink_purge_absent_suppliers(child); |
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} |
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|
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#ifdef CONFIG_SRCU |
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static DEFINE_MUTEX(device_links_lock); |
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DEFINE_STATIC_SRCU(device_links_srcu); |
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|
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static inline void device_links_write_lock(void) |
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{ |
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mutex_lock(&device_links_lock); |
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} |
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|
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static inline void device_links_write_unlock(void) |
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{ |
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mutex_unlock(&device_links_lock); |
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} |
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|
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int device_links_read_lock(void) __acquires(&device_links_srcu) |
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{ |
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return srcu_read_lock(&device_links_srcu); |
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} |
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|
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void device_links_read_unlock(int idx) __releases(&device_links_srcu) |
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{ |
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srcu_read_unlock(&device_links_srcu, idx); |
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} |
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|
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int device_links_read_lock_held(void) |
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{ |
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return srcu_read_lock_held(&device_links_srcu); |
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} |
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#else /* !CONFIG_SRCU */ |
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static DECLARE_RWSEM(device_links_lock); |
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|
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static inline void device_links_write_lock(void) |
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{ |
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down_write(&device_links_lock); |
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} |
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|
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static inline void device_links_write_unlock(void) |
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{ |
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up_write(&device_links_lock); |
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} |
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|
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int device_links_read_lock(void) |
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{ |
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down_read(&device_links_lock); |
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return 0; |
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} |
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|
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void device_links_read_unlock(int not_used) |
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{ |
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up_read(&device_links_lock); |
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} |
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|
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#ifdef CONFIG_DEBUG_LOCK_ALLOC |
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int device_links_read_lock_held(void) |
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{ |
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return lockdep_is_held(&device_links_lock); |
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} |
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#endif |
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#endif /* !CONFIG_SRCU */ |
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|
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static bool device_is_ancestor(struct device *dev, struct device *target) |
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{ |
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while (target->parent) { |
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target = target->parent; |
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if (dev == target) |
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return true; |
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} |
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return false; |
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} |
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|
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/** |
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* device_is_dependent - Check if one device depends on another one |
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* @dev: Device to check dependencies for. |
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* @target: Device to check against. |
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* |
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* Check if @target depends on @dev or any device dependent on it (its child or |
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* its consumer etc). Return 1 if that is the case or 0 otherwise. |
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*/ |
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int device_is_dependent(struct device *dev, void *target) |
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{ |
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struct device_link *link; |
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int ret; |
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|
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/* |
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* The "ancestors" check is needed to catch the case when the target |
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* device has not been completely initialized yet and it is still |
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* missing from the list of children of its parent device. |
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*/ |
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if (dev == target || device_is_ancestor(dev, target)) |
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return 1; |
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|
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ret = device_for_each_child(dev, target, device_is_dependent); |
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if (ret) |
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return ret; |
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|
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list_for_each_entry(link, &dev->links.consumers, s_node) { |
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if ((link->flags & ~DL_FLAG_INFERRED) == |
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(DL_FLAG_SYNC_STATE_ONLY | DL_FLAG_MANAGED)) |
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continue; |
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if (link->consumer == target) |
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return 1; |
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ret = device_is_dependent(link->consumer, target); |
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if (ret) |
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break; |
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} |
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return ret; |
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} |
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|
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static void device_link_init_status(struct device_link *link, |
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struct device *consumer, |
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struct device *supplier) |
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{ |
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switch (supplier->links.status) { |
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case DL_DEV_PROBING: |
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switch (consumer->links.status) { |
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case DL_DEV_PROBING: |
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/* |
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* A consumer driver can create a link to a supplier |
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* that has not completed its probing yet as long as it |
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* knows that the supplier is already functional (for |
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* example, it has just acquired some resources from the |
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* supplier). |
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*/ |
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link->status = DL_STATE_CONSUMER_PROBE; |
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break; |
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default: |
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link->status = DL_STATE_DORMANT; |
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break; |
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} |
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break; |
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case DL_DEV_DRIVER_BOUND: |
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switch (consumer->links.status) { |
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case DL_DEV_PROBING: |
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link->status = DL_STATE_CONSUMER_PROBE; |
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break; |
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case DL_DEV_DRIVER_BOUND: |
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link->status = DL_STATE_ACTIVE; |
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break; |
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default: |
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link->status = DL_STATE_AVAILABLE; |
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break; |
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} |
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break; |
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case DL_DEV_UNBINDING: |
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link->status = DL_STATE_SUPPLIER_UNBIND; |
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break; |
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default: |
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link->status = DL_STATE_DORMANT; |
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break; |
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} |
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} |
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|
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static int device_reorder_to_tail(struct device *dev, void *not_used) |
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{ |
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struct device_link *link; |
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|
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/* |
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* Devices that have not been registered yet will be put to the ends |
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* of the lists during the registration, so skip them here. |
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*/ |
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if (device_is_registered(dev)) |
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devices_kset_move_last(dev); |
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|
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if (device_pm_initialized(dev)) |
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device_pm_move_last(dev); |
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device_for_each_child(dev, NULL, device_reorder_to_tail); |
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list_for_each_entry(link, &dev->links.consumers, s_node) { |
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if ((link->flags & ~DL_FLAG_INFERRED) == |
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(DL_FLAG_SYNC_STATE_ONLY | DL_FLAG_MANAGED)) |
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continue; |
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device_reorder_to_tail(link->consumer, NULL); |
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} |
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|
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return 0; |
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} |
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|
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/** |
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* device_pm_move_to_tail - Move set of devices to the end of device lists |
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* @dev: Device to move |
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* |
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* This is a device_reorder_to_tail() wrapper taking the requisite locks. |
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* |
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* It moves the @dev along with all of its children and all of its consumers |
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* to the ends of the device_kset and dpm_list, recursively. |
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*/ |
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void device_pm_move_to_tail(struct device *dev) |
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{ |
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int idx; |
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|
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idx = device_links_read_lock(); |
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device_pm_lock(); |
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device_reorder_to_tail(dev, NULL); |
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device_pm_unlock(); |
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device_links_read_unlock(idx); |
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} |
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|
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#define to_devlink(dev) container_of((dev), struct device_link, link_dev) |
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|
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static ssize_t status_show(struct device *dev, |
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struct device_attribute *attr, char *buf) |
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{ |
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const char *output; |
|
|
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switch (to_devlink(dev)->status) { |
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case DL_STATE_NONE: |
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output = "not tracked"; |
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break; |
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case DL_STATE_DORMANT: |
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output = "dormant"; |
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break; |
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case DL_STATE_AVAILABLE: |
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output = "available"; |
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break; |
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case DL_STATE_CONSUMER_PROBE: |
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output = "consumer probing"; |
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break; |
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case DL_STATE_ACTIVE: |
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output = "active"; |
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break; |
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case DL_STATE_SUPPLIER_UNBIND: |
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output = "supplier unbinding"; |
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break; |
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default: |
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output = "unknown"; |
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break; |
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} |
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|
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return sysfs_emit(buf, "%s\n", output); |
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} |
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static DEVICE_ATTR_RO(status); |
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|
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static ssize_t auto_remove_on_show(struct device *dev, |
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struct device_attribute *attr, char *buf) |
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{ |
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struct device_link *link = to_devlink(dev); |
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const char *output; |
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|
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if (link->flags & DL_FLAG_AUTOREMOVE_SUPPLIER) |
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output = "supplier unbind"; |
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else if (link->flags & DL_FLAG_AUTOREMOVE_CONSUMER) |
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output = "consumer unbind"; |
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else |
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output = "never"; |
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|
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return sysfs_emit(buf, "%s\n", output); |
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} |
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static DEVICE_ATTR_RO(auto_remove_on); |
|
|
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static ssize_t runtime_pm_show(struct device *dev, |
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struct device_attribute *attr, char *buf) |
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{ |
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struct device_link *link = to_devlink(dev); |
|
|
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return sysfs_emit(buf, "%d\n", !!(link->flags & DL_FLAG_PM_RUNTIME)); |
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} |
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static DEVICE_ATTR_RO(runtime_pm); |
|
|
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static ssize_t sync_state_only_show(struct device *dev, |
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struct device_attribute *attr, char *buf) |
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{ |
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struct device_link *link = to_devlink(dev); |
|
|
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return sysfs_emit(buf, "%d\n", |
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!!(link->flags & DL_FLAG_SYNC_STATE_ONLY)); |
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} |
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static DEVICE_ATTR_RO(sync_state_only); |
|
|
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static struct attribute *devlink_attrs[] = { |
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&dev_attr_status.attr, |
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&dev_attr_auto_remove_on.attr, |
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&dev_attr_runtime_pm.attr, |
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&dev_attr_sync_state_only.attr, |
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NULL, |
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}; |
|
ATTRIBUTE_GROUPS(devlink); |
|
|
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static void device_link_free(struct device_link *link) |
|
{ |
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while (refcount_dec_not_one(&link->rpm_active)) |
|
pm_runtime_put(link->supplier); |
|
|
|
put_device(link->consumer); |
|
put_device(link->supplier); |
|
kfree(link); |
|
} |
|
|
|
#ifdef CONFIG_SRCU |
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static void __device_link_free_srcu(struct rcu_head *rhead) |
|
{ |
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device_link_free(container_of(rhead, struct device_link, rcu_head)); |
|
} |
|
|
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static void devlink_dev_release(struct device *dev) |
|
{ |
|
struct device_link *link = to_devlink(dev); |
|
|
|
call_srcu(&device_links_srcu, &link->rcu_head, __device_link_free_srcu); |
|
} |
|
#else |
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static void devlink_dev_release(struct device *dev) |
|
{ |
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device_link_free(to_devlink(dev)); |
|
} |
|
#endif |
|
|
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static struct class devlink_class = { |
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.name = "devlink", |
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.owner = THIS_MODULE, |
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.dev_groups = devlink_groups, |
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.dev_release = devlink_dev_release, |
|
}; |
|
|
|
static int devlink_add_symlinks(struct device *dev, |
|
struct class_interface *class_intf) |
|
{ |
|
int ret; |
|
size_t len; |
|
struct device_link *link = to_devlink(dev); |
|
struct device *sup = link->supplier; |
|
struct device *con = link->consumer; |
|
char *buf; |
|
|
|
len = max(strlen(dev_bus_name(sup)) + strlen(dev_name(sup)), |
|
strlen(dev_bus_name(con)) + strlen(dev_name(con))); |
|
len += strlen(":"); |
|
len += strlen("supplier:") + 1; |
|
buf = kzalloc(len, GFP_KERNEL); |
|
if (!buf) |
|
return -ENOMEM; |
|
|
|
ret = sysfs_create_link(&link->link_dev.kobj, &sup->kobj, "supplier"); |
|
if (ret) |
|
goto out; |
|
|
|
ret = sysfs_create_link(&link->link_dev.kobj, &con->kobj, "consumer"); |
|
if (ret) |
|
goto err_con; |
|
|
|
snprintf(buf, len, "consumer:%s:%s", dev_bus_name(con), dev_name(con)); |
|
ret = sysfs_create_link(&sup->kobj, &link->link_dev.kobj, buf); |
|
if (ret) |
|
goto err_con_dev; |
|
|
|
snprintf(buf, len, "supplier:%s:%s", dev_bus_name(sup), dev_name(sup)); |
|
ret = sysfs_create_link(&con->kobj, &link->link_dev.kobj, buf); |
|
if (ret) |
|
goto err_sup_dev; |
|
|
|
goto out; |
|
|
|
err_sup_dev: |
|
snprintf(buf, len, "consumer:%s:%s", dev_bus_name(con), dev_name(con)); |
|
sysfs_remove_link(&sup->kobj, buf); |
|
err_con_dev: |
|
sysfs_remove_link(&link->link_dev.kobj, "consumer"); |
|
err_con: |
|
sysfs_remove_link(&link->link_dev.kobj, "supplier"); |
|
out: |
|
kfree(buf); |
|
return ret; |
|
} |
|
|
|
static void devlink_remove_symlinks(struct device *dev, |
|
struct class_interface *class_intf) |
|
{ |
|
struct device_link *link = to_devlink(dev); |
|
size_t len; |
|
struct device *sup = link->supplier; |
|
struct device *con = link->consumer; |
|
char *buf; |
|
|
|
sysfs_remove_link(&link->link_dev.kobj, "consumer"); |
|
sysfs_remove_link(&link->link_dev.kobj, "supplier"); |
|
|
|
len = max(strlen(dev_bus_name(sup)) + strlen(dev_name(sup)), |
|
strlen(dev_bus_name(con)) + strlen(dev_name(con))); |
|
len += strlen(":"); |
|
len += strlen("supplier:") + 1; |
|
buf = kzalloc(len, GFP_KERNEL); |
|
if (!buf) { |
|
WARN(1, "Unable to properly free device link symlinks!\n"); |
|
return; |
|
} |
|
|
|
snprintf(buf, len, "supplier:%s:%s", dev_bus_name(sup), dev_name(sup)); |
|
sysfs_remove_link(&con->kobj, buf); |
|
snprintf(buf, len, "consumer:%s:%s", dev_bus_name(con), dev_name(con)); |
|
sysfs_remove_link(&sup->kobj, buf); |
|
kfree(buf); |
|
} |
|
|
|
static struct class_interface devlink_class_intf = { |
|
.class = &devlink_class, |
|
.add_dev = devlink_add_symlinks, |
|
.remove_dev = devlink_remove_symlinks, |
|
}; |
|
|
|
static int __init devlink_class_init(void) |
|
{ |
|
int ret; |
|
|
|
ret = class_register(&devlink_class); |
|
if (ret) |
|
return ret; |
|
|
|
ret = class_interface_register(&devlink_class_intf); |
|
if (ret) |
|
class_unregister(&devlink_class); |
|
|
|
return ret; |
|
} |
|
postcore_initcall(devlink_class_init); |
|
|
|
#define DL_MANAGED_LINK_FLAGS (DL_FLAG_AUTOREMOVE_CONSUMER | \ |
|
DL_FLAG_AUTOREMOVE_SUPPLIER | \ |
|
DL_FLAG_AUTOPROBE_CONSUMER | \ |
|
DL_FLAG_SYNC_STATE_ONLY | \ |
|
DL_FLAG_INFERRED) |
|
|
|
#define DL_ADD_VALID_FLAGS (DL_MANAGED_LINK_FLAGS | DL_FLAG_STATELESS | \ |
|
DL_FLAG_PM_RUNTIME | DL_FLAG_RPM_ACTIVE) |
|
|
|
/** |
|
* device_link_add - Create a link between two devices. |
|
* @consumer: Consumer end of the link. |
|
* @supplier: Supplier end of the link. |
|
* @flags: Link flags. |
|
* |
|
* The caller is responsible for the proper synchronization of the link creation |
|
* with runtime PM. First, setting the DL_FLAG_PM_RUNTIME flag will cause the |
|
* runtime PM framework to take the link into account. Second, if the |
|
* DL_FLAG_RPM_ACTIVE flag is set in addition to it, the supplier devices will |
|
* be forced into the active meta state and reference-counted upon the creation |
|
* of the link. If DL_FLAG_PM_RUNTIME is not set, DL_FLAG_RPM_ACTIVE will be |
|
* ignored. |
|
* |
|
* If DL_FLAG_STATELESS is set in @flags, the caller of this function is |
|
* expected to release the link returned by it directly with the help of either |
|
* device_link_del() or device_link_remove(). |
|
* |
|
* If that flag is not set, however, the caller of this function is handing the |
|
* management of the link over to the driver core entirely and its return value |
|
* can only be used to check whether or not the link is present. In that case, |
|
* the DL_FLAG_AUTOREMOVE_CONSUMER and DL_FLAG_AUTOREMOVE_SUPPLIER device link |
|
* flags can be used to indicate to the driver core when the link can be safely |
|
* deleted. Namely, setting one of them in @flags indicates to the driver core |
|
* that the link is not going to be used (by the given caller of this function) |
|
* after unbinding the consumer or supplier driver, respectively, from its |
|
* device, so the link can be deleted at that point. If none of them is set, |
|
* the link will be maintained until one of the devices pointed to by it (either |
|
* the consumer or the supplier) is unregistered. |
|
* |
|
* Also, if DL_FLAG_STATELESS, DL_FLAG_AUTOREMOVE_CONSUMER and |
|
* DL_FLAG_AUTOREMOVE_SUPPLIER are not set in @flags (that is, a persistent |
|
* managed device link is being added), the DL_FLAG_AUTOPROBE_CONSUMER flag can |
|
* be used to request the driver core to automatically probe for a consumer |
|
* driver after successfully binding a driver to the supplier device. |
|
* |
|
* The combination of DL_FLAG_STATELESS and one of DL_FLAG_AUTOREMOVE_CONSUMER, |
|
* DL_FLAG_AUTOREMOVE_SUPPLIER, or DL_FLAG_AUTOPROBE_CONSUMER set in @flags at |
|
* the same time is invalid and will cause NULL to be returned upfront. |
|
* However, if a device link between the given @consumer and @supplier pair |
|
* exists already when this function is called for them, the existing link will |
|
* be returned regardless of its current type and status (the link's flags may |
|
* be modified then). The caller of this function is then expected to treat |
|
* the link as though it has just been created, so (in particular) if |
|
* DL_FLAG_STATELESS was passed in @flags, the link needs to be released |
|
* explicitly when not needed any more (as stated above). |
|
* |
|
* A side effect of the link creation is re-ordering of dpm_list and the |
|
* devices_kset list by moving the consumer device and all devices depending |
|
* on it to the ends of these lists (that does not happen to devices that have |
|
* not been registered when this function is called). |
|
* |
|
* The supplier device is required to be registered when this function is called |
|
* and NULL will be returned if that is not the case. The consumer device need |
|
* not be registered, however. |
|
*/ |
|
struct device_link *device_link_add(struct device *consumer, |
|
struct device *supplier, u32 flags) |
|
{ |
|
struct device_link *link; |
|
|
|
if (!consumer || !supplier || flags & ~DL_ADD_VALID_FLAGS || |
|
(flags & DL_FLAG_STATELESS && flags & DL_MANAGED_LINK_FLAGS) || |
|
(flags & DL_FLAG_SYNC_STATE_ONLY && |
|
(flags & ~DL_FLAG_INFERRED) != DL_FLAG_SYNC_STATE_ONLY) || |
|
(flags & DL_FLAG_AUTOPROBE_CONSUMER && |
|
flags & (DL_FLAG_AUTOREMOVE_CONSUMER | |
|
DL_FLAG_AUTOREMOVE_SUPPLIER))) |
|
return NULL; |
|
|
|
if (flags & DL_FLAG_PM_RUNTIME && flags & DL_FLAG_RPM_ACTIVE) { |
|
if (pm_runtime_get_sync(supplier) < 0) { |
|
pm_runtime_put_noidle(supplier); |
|
return NULL; |
|
} |
|
} |
|
|
|
if (!(flags & DL_FLAG_STATELESS)) |
|
flags |= DL_FLAG_MANAGED; |
|
|
|
device_links_write_lock(); |
|
device_pm_lock(); |
|
|
|
/* |
|
* If the supplier has not been fully registered yet or there is a |
|
* reverse (non-SYNC_STATE_ONLY) dependency between the consumer and |
|
* the supplier already in the graph, return NULL. If the link is a |
|
* SYNC_STATE_ONLY link, we don't check for reverse dependencies |
|
* because it only affects sync_state() callbacks. |
|
*/ |
|
if (!device_pm_initialized(supplier) |
|
|| (!(flags & DL_FLAG_SYNC_STATE_ONLY) && |
|
device_is_dependent(consumer, supplier))) { |
|
link = NULL; |
|
goto out; |
|
} |
|
|
|
/* |
|
* SYNC_STATE_ONLY links are useless once a consumer device has probed. |
|
* So, only create it if the consumer hasn't probed yet. |
|
*/ |
|
if (flags & DL_FLAG_SYNC_STATE_ONLY && |
|
consumer->links.status != DL_DEV_NO_DRIVER && |
|
consumer->links.status != DL_DEV_PROBING) { |
|
link = NULL; |
|
goto out; |
|
} |
|
|
|
/* |
|
* DL_FLAG_AUTOREMOVE_SUPPLIER indicates that the link will be needed |
|
* longer than for DL_FLAG_AUTOREMOVE_CONSUMER and setting them both |
|
* together doesn't make sense, so prefer DL_FLAG_AUTOREMOVE_SUPPLIER. |
|
*/ |
|
if (flags & DL_FLAG_AUTOREMOVE_SUPPLIER) |
|
flags &= ~DL_FLAG_AUTOREMOVE_CONSUMER; |
|
|
|
list_for_each_entry(link, &supplier->links.consumers, s_node) { |
|
if (link->consumer != consumer) |
|
continue; |
|
|
|
if (link->flags & DL_FLAG_INFERRED && |
|
!(flags & DL_FLAG_INFERRED)) |
|
link->flags &= ~DL_FLAG_INFERRED; |
|
|
|
if (flags & DL_FLAG_PM_RUNTIME) { |
|
if (!(link->flags & DL_FLAG_PM_RUNTIME)) { |
|
pm_runtime_new_link(consumer); |
|
link->flags |= DL_FLAG_PM_RUNTIME; |
|
} |
|
if (flags & DL_FLAG_RPM_ACTIVE) |
|
refcount_inc(&link->rpm_active); |
|
} |
|
|
|
if (flags & DL_FLAG_STATELESS) { |
|
kref_get(&link->kref); |
|
if (link->flags & DL_FLAG_SYNC_STATE_ONLY && |
|
!(link->flags & DL_FLAG_STATELESS)) { |
|
link->flags |= DL_FLAG_STATELESS; |
|
goto reorder; |
|
} else { |
|
link->flags |= DL_FLAG_STATELESS; |
|
goto out; |
|
} |
|
} |
|
|
|
/* |
|
* If the life time of the link following from the new flags is |
|
* longer than indicated by the flags of the existing link, |
|
* update the existing link to stay around longer. |
|
*/ |
|
if (flags & DL_FLAG_AUTOREMOVE_SUPPLIER) { |
|
if (link->flags & DL_FLAG_AUTOREMOVE_CONSUMER) { |
|
link->flags &= ~DL_FLAG_AUTOREMOVE_CONSUMER; |
|
link->flags |= DL_FLAG_AUTOREMOVE_SUPPLIER; |
|
} |
|
} else if (!(flags & DL_FLAG_AUTOREMOVE_CONSUMER)) { |
|
link->flags &= ~(DL_FLAG_AUTOREMOVE_CONSUMER | |
|
DL_FLAG_AUTOREMOVE_SUPPLIER); |
|
} |
|
if (!(link->flags & DL_FLAG_MANAGED)) { |
|
kref_get(&link->kref); |
|
link->flags |= DL_FLAG_MANAGED; |
|
device_link_init_status(link, consumer, supplier); |
|
} |
|
if (link->flags & DL_FLAG_SYNC_STATE_ONLY && |
|
!(flags & DL_FLAG_SYNC_STATE_ONLY)) { |
|
link->flags &= ~DL_FLAG_SYNC_STATE_ONLY; |
|
goto reorder; |
|
} |
|
|
|
goto out; |
|
} |
|
|
|
link = kzalloc(sizeof(*link), GFP_KERNEL); |
|
if (!link) |
|
goto out; |
|
|
|
refcount_set(&link->rpm_active, 1); |
|
|
|
get_device(supplier); |
|
link->supplier = supplier; |
|
INIT_LIST_HEAD(&link->s_node); |
|
get_device(consumer); |
|
link->consumer = consumer; |
|
INIT_LIST_HEAD(&link->c_node); |
|
link->flags = flags; |
|
kref_init(&link->kref); |
|
|
|
link->link_dev.class = &devlink_class; |
|
device_set_pm_not_required(&link->link_dev); |
|
dev_set_name(&link->link_dev, "%s:%s--%s:%s", |
|
dev_bus_name(supplier), dev_name(supplier), |
|
dev_bus_name(consumer), dev_name(consumer)); |
|
if (device_register(&link->link_dev)) { |
|
put_device(consumer); |
|
put_device(supplier); |
|
kfree(link); |
|
link = NULL; |
|
goto out; |
|
} |
|
|
|
if (flags & DL_FLAG_PM_RUNTIME) { |
|
if (flags & DL_FLAG_RPM_ACTIVE) |
|
refcount_inc(&link->rpm_active); |
|
|
|
pm_runtime_new_link(consumer); |
|
} |
|
|
|
/* Determine the initial link state. */ |
|
if (flags & DL_FLAG_STATELESS) |
|
link->status = DL_STATE_NONE; |
|
else |
|
device_link_init_status(link, consumer, supplier); |
|
|
|
/* |
|
* Some callers expect the link creation during consumer driver probe to |
|
* resume the supplier even without DL_FLAG_RPM_ACTIVE. |
|
*/ |
|
if (link->status == DL_STATE_CONSUMER_PROBE && |
|
flags & DL_FLAG_PM_RUNTIME) |
|
pm_runtime_resume(supplier); |
|
|
|
list_add_tail_rcu(&link->s_node, &supplier->links.consumers); |
|
list_add_tail_rcu(&link->c_node, &consumer->links.suppliers); |
|
|
|
if (flags & DL_FLAG_SYNC_STATE_ONLY) { |
|
dev_dbg(consumer, |
|
"Linked as a sync state only consumer to %s\n", |
|
dev_name(supplier)); |
|
goto out; |
|
} |
|
|
|
reorder: |
|
/* |
|
* Move the consumer and all of the devices depending on it to the end |
|
* of dpm_list and the devices_kset list. |
|
* |
|
* It is necessary to hold dpm_list locked throughout all that or else |
|
* we may end up suspending with a wrong ordering of it. |
|
*/ |
|
device_reorder_to_tail(consumer, NULL); |
|
|
|
dev_dbg(consumer, "Linked as a consumer to %s\n", dev_name(supplier)); |
|
|
|
out: |
|
device_pm_unlock(); |
|
device_links_write_unlock(); |
|
|
|
if ((flags & DL_FLAG_PM_RUNTIME && flags & DL_FLAG_RPM_ACTIVE) && !link) |
|
pm_runtime_put(supplier); |
|
|
|
return link; |
|
} |
|
EXPORT_SYMBOL_GPL(device_link_add); |
|
|
|
#ifdef CONFIG_SRCU |
|
static void __device_link_del(struct kref *kref) |
|
{ |
|
struct device_link *link = container_of(kref, struct device_link, kref); |
|
|
|
dev_dbg(link->consumer, "Dropping the link to %s\n", |
|
dev_name(link->supplier)); |
|
|
|
pm_runtime_drop_link(link); |
|
|
|
list_del_rcu(&link->s_node); |
|
list_del_rcu(&link->c_node); |
|
device_unregister(&link->link_dev); |
|
} |
|
#else /* !CONFIG_SRCU */ |
|
static void __device_link_del(struct kref *kref) |
|
{ |
|
struct device_link *link = container_of(kref, struct device_link, kref); |
|
|
|
dev_info(link->consumer, "Dropping the link to %s\n", |
|
dev_name(link->supplier)); |
|
|
|
pm_runtime_drop_link(link); |
|
|
|
list_del(&link->s_node); |
|
list_del(&link->c_node); |
|
device_unregister(&link->link_dev); |
|
} |
|
#endif /* !CONFIG_SRCU */ |
|
|
|
static void device_link_put_kref(struct device_link *link) |
|
{ |
|
if (link->flags & DL_FLAG_STATELESS) |
|
kref_put(&link->kref, __device_link_del); |
|
else |
|
WARN(1, "Unable to drop a managed device link reference\n"); |
|
} |
|
|
|
/** |
|
* device_link_del - Delete a stateless link between two devices. |
|
* @link: Device link to delete. |
|
* |
|
* The caller must ensure proper synchronization of this function with runtime |
|
* PM. If the link was added multiple times, it needs to be deleted as often. |
|
* Care is required for hotplugged devices: Their links are purged on removal |
|
* and calling device_link_del() is then no longer allowed. |
|
*/ |
|
void device_link_del(struct device_link *link) |
|
{ |
|
device_links_write_lock(); |
|
device_link_put_kref(link); |
|
device_links_write_unlock(); |
|
} |
|
EXPORT_SYMBOL_GPL(device_link_del); |
|
|
|
/** |
|
* device_link_remove - Delete a stateless link between two devices. |
|
* @consumer: Consumer end of the link. |
|
* @supplier: Supplier end of the link. |
|
* |
|
* The caller must ensure proper synchronization of this function with runtime |
|
* PM. |
|
*/ |
|
void device_link_remove(void *consumer, struct device *supplier) |
|
{ |
|
struct device_link *link; |
|
|
|
if (WARN_ON(consumer == supplier)) |
|
return; |
|
|
|
device_links_write_lock(); |
|
|
|
list_for_each_entry(link, &supplier->links.consumers, s_node) { |
|
if (link->consumer == consumer) { |
|
device_link_put_kref(link); |
|
break; |
|
} |
|
} |
|
|
|
device_links_write_unlock(); |
|
} |
|
EXPORT_SYMBOL_GPL(device_link_remove); |
|
|
|
static void device_links_missing_supplier(struct device *dev) |
|
{ |
|
struct device_link *link; |
|
|
|
list_for_each_entry(link, &dev->links.suppliers, c_node) { |
|
if (link->status != DL_STATE_CONSUMER_PROBE) |
|
continue; |
|
|
|
if (link->supplier->links.status == DL_DEV_DRIVER_BOUND) { |
|
WRITE_ONCE(link->status, DL_STATE_AVAILABLE); |
|
} else { |
|
WARN_ON(!(link->flags & DL_FLAG_SYNC_STATE_ONLY)); |
|
WRITE_ONCE(link->status, DL_STATE_DORMANT); |
|
} |
|
} |
|
} |
|
|
|
/** |
|
* device_links_check_suppliers - Check presence of supplier drivers. |
|
* @dev: Consumer device. |
|
* |
|
* Check links from this device to any suppliers. Walk the list of the device's |
|
* links to suppliers and see if all of them are available. If not, simply |
|
* return -EPROBE_DEFER. |
|
* |
|
* We need to guarantee that the supplier will not go away after the check has |
|
* been positive here. It only can go away in __device_release_driver() and |
|
* that function checks the device's links to consumers. This means we need to |
|
* mark the link as "consumer probe in progress" to make the supplier removal |
|
* wait for us to complete (or bad things may happen). |
|
* |
|
* Links without the DL_FLAG_MANAGED flag set are ignored. |
|
*/ |
|
int device_links_check_suppliers(struct device *dev) |
|
{ |
|
struct device_link *link; |
|
int ret = 0; |
|
|
|
/* |
|
* Device waiting for supplier to become available is not allowed to |
|
* probe. |
|
*/ |
|
mutex_lock(&fwnode_link_lock); |
|
if (dev->fwnode && !list_empty(&dev->fwnode->suppliers) && |
|
!fw_devlink_is_permissive()) { |
|
dev_dbg(dev, "probe deferral - wait for supplier %pfwP\n", |
|
list_first_entry(&dev->fwnode->suppliers, |
|
struct fwnode_link, |
|
c_hook)->supplier); |
|
mutex_unlock(&fwnode_link_lock); |
|
return -EPROBE_DEFER; |
|
} |
|
mutex_unlock(&fwnode_link_lock); |
|
|
|
device_links_write_lock(); |
|
|
|
list_for_each_entry(link, &dev->links.suppliers, c_node) { |
|
if (!(link->flags & DL_FLAG_MANAGED)) |
|
continue; |
|
|
|
if (link->status != DL_STATE_AVAILABLE && |
|
!(link->flags & DL_FLAG_SYNC_STATE_ONLY)) { |
|
device_links_missing_supplier(dev); |
|
dev_dbg(dev, "probe deferral - supplier %s not ready\n", |
|
dev_name(link->supplier)); |
|
ret = -EPROBE_DEFER; |
|
break; |
|
} |
|
WRITE_ONCE(link->status, DL_STATE_CONSUMER_PROBE); |
|
} |
|
dev->links.status = DL_DEV_PROBING; |
|
|
|
device_links_write_unlock(); |
|
return ret; |
|
} |
|
|
|
/** |
|
* __device_links_queue_sync_state - Queue a device for sync_state() callback |
|
* @dev: Device to call sync_state() on |
|
* @list: List head to queue the @dev on |
|
* |
|
* Queues a device for a sync_state() callback when the device links write lock |
|
* isn't held. This allows the sync_state() execution flow to use device links |
|
* APIs. The caller must ensure this function is called with |
|
* device_links_write_lock() held. |
|
* |
|
* This function does a get_device() to make sure the device is not freed while |
|
* on this list. |
|
* |
|
* So the caller must also ensure that device_links_flush_sync_list() is called |
|
* as soon as the caller releases device_links_write_lock(). This is necessary |
|
* to make sure the sync_state() is called in a timely fashion and the |
|
* put_device() is called on this device. |
|
*/ |
|
static void __device_links_queue_sync_state(struct device *dev, |
|
struct list_head *list) |
|
{ |
|
struct device_link *link; |
|
|
|
if (!dev_has_sync_state(dev)) |
|
return; |
|
if (dev->state_synced) |
|
return; |
|
|
|
list_for_each_entry(link, &dev->links.consumers, s_node) { |
|
if (!(link->flags & DL_FLAG_MANAGED)) |
|
continue; |
|
if (link->status != DL_STATE_ACTIVE) |
|
return; |
|
} |
|
|
|
/* |
|
* Set the flag here to avoid adding the same device to a list more |
|
* than once. This can happen if new consumers get added to the device |
|
* and probed before the list is flushed. |
|
*/ |
|
dev->state_synced = true; |
|
|
|
if (WARN_ON(!list_empty(&dev->links.defer_sync))) |
|
return; |
|
|
|
get_device(dev); |
|
list_add_tail(&dev->links.defer_sync, list); |
|
} |
|
|
|
/** |
|
* device_links_flush_sync_list - Call sync_state() on a list of devices |
|
* @list: List of devices to call sync_state() on |
|
* @dont_lock_dev: Device for which lock is already held by the caller |
|
* |
|
* Calls sync_state() on all the devices that have been queued for it. This |
|
* function is used in conjunction with __device_links_queue_sync_state(). The |
|
* @dont_lock_dev parameter is useful when this function is called from a |
|
* context where a device lock is already held. |
|
*/ |
|
static void device_links_flush_sync_list(struct list_head *list, |
|
struct device *dont_lock_dev) |
|
{ |
|
struct device *dev, *tmp; |
|
|
|
list_for_each_entry_safe(dev, tmp, list, links.defer_sync) { |
|
list_del_init(&dev->links.defer_sync); |
|
|
|
if (dev != dont_lock_dev) |
|
device_lock(dev); |
|
|
|
if (dev->bus->sync_state) |
|
dev->bus->sync_state(dev); |
|
else if (dev->driver && dev->driver->sync_state) |
|
dev->driver->sync_state(dev); |
|
|
|
if (dev != dont_lock_dev) |
|
device_unlock(dev); |
|
|
|
put_device(dev); |
|
} |
|
} |
|
|
|
void device_links_supplier_sync_state_pause(void) |
|
{ |
|
device_links_write_lock(); |
|
defer_sync_state_count++; |
|
device_links_write_unlock(); |
|
} |
|
|
|
void device_links_supplier_sync_state_resume(void) |
|
{ |
|
struct device *dev, *tmp; |
|
LIST_HEAD(sync_list); |
|
|
|
device_links_write_lock(); |
|
if (!defer_sync_state_count) { |
|
WARN(true, "Unmatched sync_state pause/resume!"); |
|
goto out; |
|
} |
|
defer_sync_state_count--; |
|
if (defer_sync_state_count) |
|
goto out; |
|
|
|
list_for_each_entry_safe(dev, tmp, &deferred_sync, links.defer_sync) { |
|
/* |
|
* Delete from deferred_sync list before queuing it to |
|
* sync_list because defer_sync is used for both lists. |
|
*/ |
|
list_del_init(&dev->links.defer_sync); |
|
__device_links_queue_sync_state(dev, &sync_list); |
|
} |
|
out: |
|
device_links_write_unlock(); |
|
|
|
device_links_flush_sync_list(&sync_list, NULL); |
|
} |
|
|
|
static int sync_state_resume_initcall(void) |
|
{ |
|
device_links_supplier_sync_state_resume(); |
|
return 0; |
|
} |
|
late_initcall(sync_state_resume_initcall); |
|
|
|
static void __device_links_supplier_defer_sync(struct device *sup) |
|
{ |
|
if (list_empty(&sup->links.defer_sync) && dev_has_sync_state(sup)) |
|
list_add_tail(&sup->links.defer_sync, &deferred_sync); |
|
} |
|
|
|
static void device_link_drop_managed(struct device_link *link) |
|
{ |
|
link->flags &= ~DL_FLAG_MANAGED; |
|
WRITE_ONCE(link->status, DL_STATE_NONE); |
|
kref_put(&link->kref, __device_link_del); |
|
} |
|
|
|
static ssize_t waiting_for_supplier_show(struct device *dev, |
|
struct device_attribute *attr, |
|
char *buf) |
|
{ |
|
bool val; |
|
|
|
device_lock(dev); |
|
val = !list_empty(&dev->fwnode->suppliers); |
|
device_unlock(dev); |
|
return sysfs_emit(buf, "%u\n", val); |
|
} |
|
static DEVICE_ATTR_RO(waiting_for_supplier); |
|
|
|
/** |
|
* device_links_driver_bound - Update device links after probing its driver. |
|
* @dev: Device to update the links for. |
|
* |
|
* The probe has been successful, so update links from this device to any |
|
* consumers by changing their status to "available". |
|
* |
|
* Also change the status of @dev's links to suppliers to "active". |
|
* |
|
* Links without the DL_FLAG_MANAGED flag set are ignored. |
|
*/ |
|
void device_links_driver_bound(struct device *dev) |
|
{ |
|
struct device_link *link, *ln; |
|
LIST_HEAD(sync_list); |
|
|
|
/* |
|
* If a device binds successfully, it's expected to have created all |
|
* the device links it needs to or make new device links as it needs |
|
* them. So, fw_devlink no longer needs to create device links to any |
|
* of the device's suppliers. |
|
* |
|
* Also, if a child firmware node of this bound device is not added as |
|
* a device by now, assume it is never going to be added and make sure |
|
* other devices don't defer probe indefinitely by waiting for such a |
|
* child device. |
|
*/ |
|
if (dev->fwnode && dev->fwnode->dev == dev) { |
|
struct fwnode_handle *child; |
|
fwnode_links_purge_suppliers(dev->fwnode); |
|
fwnode_for_each_available_child_node(dev->fwnode, child) |
|
fw_devlink_purge_absent_suppliers(child); |
|
} |
|
device_remove_file(dev, &dev_attr_waiting_for_supplier); |
|
|
|
device_links_write_lock(); |
|
|
|
list_for_each_entry(link, &dev->links.consumers, s_node) { |
|
if (!(link->flags & DL_FLAG_MANAGED)) |
|
continue; |
|
|
|
/* |
|
* Links created during consumer probe may be in the "consumer |
|
* probe" state to start with if the supplier is still probing |
|
* when they are created and they may become "active" if the |
|
* consumer probe returns first. Skip them here. |
|
*/ |
|
if (link->status == DL_STATE_CONSUMER_PROBE || |
|
link->status == DL_STATE_ACTIVE) |
|
continue; |
|
|
|
WARN_ON(link->status != DL_STATE_DORMANT); |
|
WRITE_ONCE(link->status, DL_STATE_AVAILABLE); |
|
|
|
if (link->flags & DL_FLAG_AUTOPROBE_CONSUMER) |
|
driver_deferred_probe_add(link->consumer); |
|
} |
|
|
|
if (defer_sync_state_count) |
|
__device_links_supplier_defer_sync(dev); |
|
else |
|
__device_links_queue_sync_state(dev, &sync_list); |
|
|
|
list_for_each_entry_safe(link, ln, &dev->links.suppliers, c_node) { |
|
struct device *supplier; |
|
|
|
if (!(link->flags & DL_FLAG_MANAGED)) |
|
continue; |
|
|
|
supplier = link->supplier; |
|
if (link->flags & DL_FLAG_SYNC_STATE_ONLY) { |
|
/* |
|
* When DL_FLAG_SYNC_STATE_ONLY is set, it means no |
|
* other DL_MANAGED_LINK_FLAGS have been set. So, it's |
|
* save to drop the managed link completely. |
|
*/ |
|
device_link_drop_managed(link); |
|
} else { |
|
WARN_ON(link->status != DL_STATE_CONSUMER_PROBE); |
|
WRITE_ONCE(link->status, DL_STATE_ACTIVE); |
|
} |
|
|
|
/* |
|
* This needs to be done even for the deleted |
|
* DL_FLAG_SYNC_STATE_ONLY device link in case it was the last |
|
* device link that was preventing the supplier from getting a |
|
* sync_state() call. |
|
*/ |
|
if (defer_sync_state_count) |
|
__device_links_supplier_defer_sync(supplier); |
|
else |
|
__device_links_queue_sync_state(supplier, &sync_list); |
|
} |
|
|
|
dev->links.status = DL_DEV_DRIVER_BOUND; |
|
|
|
device_links_write_unlock(); |
|
|
|
device_links_flush_sync_list(&sync_list, dev); |
|
} |
|
|
|
/** |
|
* __device_links_no_driver - Update links of a device without a driver. |
|
* @dev: Device without a drvier. |
|
* |
|
* Delete all non-persistent links from this device to any suppliers. |
|
* |
|
* Persistent links stay around, but their status is changed to "available", |
|
* unless they already are in the "supplier unbind in progress" state in which |
|
* case they need not be updated. |
|
* |
|
* Links without the DL_FLAG_MANAGED flag set are ignored. |
|
*/ |
|
static void __device_links_no_driver(struct device *dev) |
|
{ |
|
struct device_link *link, *ln; |
|
|
|
list_for_each_entry_safe_reverse(link, ln, &dev->links.suppliers, c_node) { |
|
if (!(link->flags & DL_FLAG_MANAGED)) |
|
continue; |
|
|
|
if (link->flags & DL_FLAG_AUTOREMOVE_CONSUMER) { |
|
device_link_drop_managed(link); |
|
continue; |
|
} |
|
|
|
if (link->status != DL_STATE_CONSUMER_PROBE && |
|
link->status != DL_STATE_ACTIVE) |
|
continue; |
|
|
|
if (link->supplier->links.status == DL_DEV_DRIVER_BOUND) { |
|
WRITE_ONCE(link->status, DL_STATE_AVAILABLE); |
|
} else { |
|
WARN_ON(!(link->flags & DL_FLAG_SYNC_STATE_ONLY)); |
|
WRITE_ONCE(link->status, DL_STATE_DORMANT); |
|
} |
|
} |
|
|
|
dev->links.status = DL_DEV_NO_DRIVER; |
|
} |
|
|
|
/** |
|
* device_links_no_driver - Update links after failing driver probe. |
|
* @dev: Device whose driver has just failed to probe. |
|
* |
|
* Clean up leftover links to consumers for @dev and invoke |
|
* %__device_links_no_driver() to update links to suppliers for it as |
|
* appropriate. |
|
* |
|
* Links without the DL_FLAG_MANAGED flag set are ignored. |
|
*/ |
|
void device_links_no_driver(struct device *dev) |
|
{ |
|
struct device_link *link; |
|
|
|
device_links_write_lock(); |
|
|
|
list_for_each_entry(link, &dev->links.consumers, s_node) { |
|
if (!(link->flags & DL_FLAG_MANAGED)) |
|
continue; |
|
|
|
/* |
|
* The probe has failed, so if the status of the link is |
|
* "consumer probe" or "active", it must have been added by |
|
* a probing consumer while this device was still probing. |
|
* Change its state to "dormant", as it represents a valid |
|
* relationship, but it is not functionally meaningful. |
|
*/ |
|
if (link->status == DL_STATE_CONSUMER_PROBE || |
|
link->status == DL_STATE_ACTIVE) |
|
WRITE_ONCE(link->status, DL_STATE_DORMANT); |
|
} |
|
|
|
__device_links_no_driver(dev); |
|
|
|
device_links_write_unlock(); |
|
} |
|
|
|
/** |
|
* device_links_driver_cleanup - Update links after driver removal. |
|
* @dev: Device whose driver has just gone away. |
|
* |
|
* Update links to consumers for @dev by changing their status to "dormant" and |
|
* invoke %__device_links_no_driver() to update links to suppliers for it as |
|
* appropriate. |
|
* |
|
* Links without the DL_FLAG_MANAGED flag set are ignored. |
|
*/ |
|
void device_links_driver_cleanup(struct device *dev) |
|
{ |
|
struct device_link *link, *ln; |
|
|
|
device_links_write_lock(); |
|
|
|
list_for_each_entry_safe(link, ln, &dev->links.consumers, s_node) { |
|
if (!(link->flags & DL_FLAG_MANAGED)) |
|
continue; |
|
|
|
WARN_ON(link->flags & DL_FLAG_AUTOREMOVE_CONSUMER); |
|
WARN_ON(link->status != DL_STATE_SUPPLIER_UNBIND); |
|
|
|
/* |
|
* autoremove the links between this @dev and its consumer |
|
* devices that are not active, i.e. where the link state |
|
* has moved to DL_STATE_SUPPLIER_UNBIND. |
|
*/ |
|
if (link->status == DL_STATE_SUPPLIER_UNBIND && |
|
link->flags & DL_FLAG_AUTOREMOVE_SUPPLIER) |
|
device_link_drop_managed(link); |
|
|
|
WRITE_ONCE(link->status, DL_STATE_DORMANT); |
|
} |
|
|
|
list_del_init(&dev->links.defer_sync); |
|
__device_links_no_driver(dev); |
|
|
|
device_links_write_unlock(); |
|
} |
|
|
|
/** |
|
* device_links_busy - Check if there are any busy links to consumers. |
|
* @dev: Device to check. |
|
* |
|
* Check each consumer of the device and return 'true' if its link's status |
|
* is one of "consumer probe" or "active" (meaning that the given consumer is |
|
* probing right now or its driver is present). Otherwise, change the link |
|
* state to "supplier unbind" to prevent the consumer from being probed |
|
* successfully going forward. |
|
* |
|
* Return 'false' if there are no probing or active consumers. |
|
* |
|
* Links without the DL_FLAG_MANAGED flag set are ignored. |
|
*/ |
|
bool device_links_busy(struct device *dev) |
|
{ |
|
struct device_link *link; |
|
bool ret = false; |
|
|
|
device_links_write_lock(); |
|
|
|
list_for_each_entry(link, &dev->links.consumers, s_node) { |
|
if (!(link->flags & DL_FLAG_MANAGED)) |
|
continue; |
|
|
|
if (link->status == DL_STATE_CONSUMER_PROBE |
|
|| link->status == DL_STATE_ACTIVE) { |
|
ret = true; |
|
break; |
|
} |
|
WRITE_ONCE(link->status, DL_STATE_SUPPLIER_UNBIND); |
|
} |
|
|
|
dev->links.status = DL_DEV_UNBINDING; |
|
|
|
device_links_write_unlock(); |
|
return ret; |
|
} |
|
|
|
/** |
|
* device_links_unbind_consumers - Force unbind consumers of the given device. |
|
* @dev: Device to unbind the consumers of. |
|
* |
|
* Walk the list of links to consumers for @dev and if any of them is in the |
|
* "consumer probe" state, wait for all device probes in progress to complete |
|
* and start over. |
|
* |
|
* If that's not the case, change the status of the link to "supplier unbind" |
|
* and check if the link was in the "active" state. If so, force the consumer |
|
* driver to unbind and start over (the consumer will not re-probe as we have |
|
* changed the state of the link already). |
|
* |
|
* Links without the DL_FLAG_MANAGED flag set are ignored. |
|
*/ |
|
void device_links_unbind_consumers(struct device *dev) |
|
{ |
|
struct device_link *link; |
|
|
|
start: |
|
device_links_write_lock(); |
|
|
|
list_for_each_entry(link, &dev->links.consumers, s_node) { |
|
enum device_link_state status; |
|
|
|
if (!(link->flags & DL_FLAG_MANAGED) || |
|
link->flags & DL_FLAG_SYNC_STATE_ONLY) |
|
continue; |
|
|
|
status = link->status; |
|
if (status == DL_STATE_CONSUMER_PROBE) { |
|
device_links_write_unlock(); |
|
|
|
wait_for_device_probe(); |
|
goto start; |
|
} |
|
WRITE_ONCE(link->status, DL_STATE_SUPPLIER_UNBIND); |
|
if (status == DL_STATE_ACTIVE) { |
|
struct device *consumer = link->consumer; |
|
|
|
get_device(consumer); |
|
|
|
device_links_write_unlock(); |
|
|
|
device_release_driver_internal(consumer, NULL, |
|
consumer->parent); |
|
put_device(consumer); |
|
goto start; |
|
} |
|
} |
|
|
|
device_links_write_unlock(); |
|
} |
|
|
|
/** |
|
* device_links_purge - Delete existing links to other devices. |
|
* @dev: Target device. |
|
*/ |
|
static void device_links_purge(struct device *dev) |
|
{ |
|
struct device_link *link, *ln; |
|
|
|
if (dev->class == &devlink_class) |
|
return; |
|
|
|
/* |
|
* Delete all of the remaining links from this device to any other |
|
* devices (either consumers or suppliers). |
|
*/ |
|
device_links_write_lock(); |
|
|
|
list_for_each_entry_safe_reverse(link, ln, &dev->links.suppliers, c_node) { |
|
WARN_ON(link->status == DL_STATE_ACTIVE); |
|
__device_link_del(&link->kref); |
|
} |
|
|
|
list_for_each_entry_safe_reverse(link, ln, &dev->links.consumers, s_node) { |
|
WARN_ON(link->status != DL_STATE_DORMANT && |
|
link->status != DL_STATE_NONE); |
|
__device_link_del(&link->kref); |
|
} |
|
|
|
device_links_write_unlock(); |
|
} |
|
|
|
#define FW_DEVLINK_FLAGS_PERMISSIVE (DL_FLAG_INFERRED | \ |
|
DL_FLAG_SYNC_STATE_ONLY) |
|
#define FW_DEVLINK_FLAGS_ON (DL_FLAG_INFERRED | \ |
|
DL_FLAG_AUTOPROBE_CONSUMER) |
|
#define FW_DEVLINK_FLAGS_RPM (FW_DEVLINK_FLAGS_ON | \ |
|
DL_FLAG_PM_RUNTIME) |
|
|
|
static u32 fw_devlink_flags = FW_DEVLINK_FLAGS_PERMISSIVE; |
|
static int __init fw_devlink_setup(char *arg) |
|
{ |
|
if (!arg) |
|
return -EINVAL; |
|
|
|
if (strcmp(arg, "off") == 0) { |
|
fw_devlink_flags = 0; |
|
} else if (strcmp(arg, "permissive") == 0) { |
|
fw_devlink_flags = FW_DEVLINK_FLAGS_PERMISSIVE; |
|
} else if (strcmp(arg, "on") == 0) { |
|
fw_devlink_flags = FW_DEVLINK_FLAGS_ON; |
|
} else if (strcmp(arg, "rpm") == 0) { |
|
fw_devlink_flags = FW_DEVLINK_FLAGS_RPM; |
|
} |
|
return 0; |
|
} |
|
early_param("fw_devlink", fw_devlink_setup); |
|
|
|
static bool fw_devlink_strict; |
|
static int __init fw_devlink_strict_setup(char *arg) |
|
{ |
|
return strtobool(arg, &fw_devlink_strict); |
|
} |
|
early_param("fw_devlink.strict", fw_devlink_strict_setup); |
|
|
|
u32 fw_devlink_get_flags(void) |
|
{ |
|
return fw_devlink_flags; |
|
} |
|
|
|
static bool fw_devlink_is_permissive(void) |
|
{ |
|
return fw_devlink_flags == FW_DEVLINK_FLAGS_PERMISSIVE; |
|
} |
|
|
|
bool fw_devlink_is_strict(void) |
|
{ |
|
return fw_devlink_strict && !fw_devlink_is_permissive(); |
|
} |
|
|
|
static void fw_devlink_parse_fwnode(struct fwnode_handle *fwnode) |
|
{ |
|
if (fwnode->flags & FWNODE_FLAG_LINKS_ADDED) |
|
return; |
|
|
|
fwnode_call_int_op(fwnode, add_links); |
|
fwnode->flags |= FWNODE_FLAG_LINKS_ADDED; |
|
} |
|
|
|
static void fw_devlink_parse_fwtree(struct fwnode_handle *fwnode) |
|
{ |
|
struct fwnode_handle *child = NULL; |
|
|
|
fw_devlink_parse_fwnode(fwnode); |
|
|
|
while ((child = fwnode_get_next_available_child_node(fwnode, child))) |
|
fw_devlink_parse_fwtree(child); |
|
} |
|
|
|
/** |
|
* fw_devlink_relax_cycle - Convert cyclic links to SYNC_STATE_ONLY links |
|
* @con: Device to check dependencies for. |
|
* @sup: Device to check against. |
|
* |
|
* Check if @sup depends on @con or any device dependent on it (its child or |
|
* its consumer etc). When such a cyclic dependency is found, convert all |
|
* device links created solely by fw_devlink into SYNC_STATE_ONLY device links. |
|
* This is the equivalent of doing fw_devlink=permissive just between the |
|
* devices in the cycle. We need to do this because, at this point, fw_devlink |
|
* can't tell which of these dependencies is not a real dependency. |
|
* |
|
* Return 1 if a cycle is found. Otherwise, return 0. |
|
*/ |
|
static int fw_devlink_relax_cycle(struct device *con, void *sup) |
|
{ |
|
struct device_link *link; |
|
int ret; |
|
|
|
if (con == sup) |
|
return 1; |
|
|
|
ret = device_for_each_child(con, sup, fw_devlink_relax_cycle); |
|
if (ret) |
|
return ret; |
|
|
|
list_for_each_entry(link, &con->links.consumers, s_node) { |
|
if ((link->flags & ~DL_FLAG_INFERRED) == |
|
(DL_FLAG_SYNC_STATE_ONLY | DL_FLAG_MANAGED)) |
|
continue; |
|
|
|
if (!fw_devlink_relax_cycle(link->consumer, sup)) |
|
continue; |
|
|
|
ret = 1; |
|
|
|
if (!(link->flags & DL_FLAG_INFERRED)) |
|
continue; |
|
|
|
pm_runtime_drop_link(link); |
|
link->flags = DL_FLAG_MANAGED | FW_DEVLINK_FLAGS_PERMISSIVE; |
|
dev_dbg(link->consumer, "Relaxing link with %s\n", |
|
dev_name(link->supplier)); |
|
} |
|
return ret; |
|
} |
|
|
|
/** |
|
* fw_devlink_create_devlink - Create a device link from a consumer to fwnode |
|
* @con - Consumer device for the device link |
|
* @sup_handle - fwnode handle of supplier |
|
* |
|
* This function will try to create a device link between the consumer device |
|
* @con and the supplier device represented by @sup_handle. |
|
* |
|
* The supplier has to be provided as a fwnode because incorrect cycles in |
|
* fwnode links can sometimes cause the supplier device to never be created. |
|
* This function detects such cases and returns an error if it cannot create a |
|
* device link from the consumer to a missing supplier. |
|
* |
|
* Returns, |
|
* 0 on successfully creating a device link |
|
* -EINVAL if the device link cannot be created as expected |
|
* -EAGAIN if the device link cannot be created right now, but it may be |
|
* possible to do that in the future |
|
*/ |
|
static int fw_devlink_create_devlink(struct device *con, |
|
struct fwnode_handle *sup_handle, u32 flags) |
|
{ |
|
struct device *sup_dev; |
|
int ret = 0; |
|
|
|
sup_dev = get_dev_from_fwnode(sup_handle); |
|
if (sup_dev) { |
|
/* |
|
* If it's one of those drivers that don't actually bind to |
|
* their device using driver core, then don't wait on this |
|
* supplier device indefinitely. |
|
*/ |
|
if (sup_dev->links.status == DL_DEV_NO_DRIVER && |
|
sup_handle->flags & FWNODE_FLAG_INITIALIZED) { |
|
ret = -EINVAL; |
|
goto out; |
|
} |
|
|
|
/* |
|
* If this fails, it is due to cycles in device links. Just |
|
* give up on this link and treat it as invalid. |
|
*/ |
|
if (!device_link_add(con, sup_dev, flags) && |
|
!(flags & DL_FLAG_SYNC_STATE_ONLY)) { |
|
dev_info(con, "Fixing up cyclic dependency with %s\n", |
|
dev_name(sup_dev)); |
|
device_links_write_lock(); |
|
fw_devlink_relax_cycle(con, sup_dev); |
|
device_links_write_unlock(); |
|
device_link_add(con, sup_dev, |
|
FW_DEVLINK_FLAGS_PERMISSIVE); |
|
ret = -EINVAL; |
|
} |
|
|
|
goto out; |
|
} |
|
|
|
/* Supplier that's already initialized without a struct device. */ |
|
if (sup_handle->flags & FWNODE_FLAG_INITIALIZED) |
|
return -EINVAL; |
|
|
|
/* |
|
* DL_FLAG_SYNC_STATE_ONLY doesn't block probing and supports |
|
* cycles. So cycle detection isn't necessary and shouldn't be |
|
* done. |
|
*/ |
|
if (flags & DL_FLAG_SYNC_STATE_ONLY) |
|
return -EAGAIN; |
|
|
|
/* |
|
* If we can't find the supplier device from its fwnode, it might be |
|
* due to a cyclic dependency between fwnodes. Some of these cycles can |
|
* be broken by applying logic. Check for these types of cycles and |
|
* break them so that devices in the cycle probe properly. |
|
* |
|
* If the supplier's parent is dependent on the consumer, then |
|
* the consumer-supplier dependency is a false dependency. So, |
|
* treat it as an invalid link. |
|
*/ |
|
sup_dev = fwnode_get_next_parent_dev(sup_handle); |
|
if (sup_dev && device_is_dependent(con, sup_dev)) { |
|
dev_dbg(con, "Not linking to %pfwP - False link\n", |
|
sup_handle); |
|
ret = -EINVAL; |
|
} else { |
|
/* |
|
* Can't check for cycles or no cycles. So let's try |
|
* again later. |
|
*/ |
|
ret = -EAGAIN; |
|
} |
|
|
|
out: |
|
put_device(sup_dev); |
|
return ret; |
|
} |
|
|
|
/** |
|
* __fw_devlink_link_to_consumers - Create device links to consumers of a device |
|
* @dev - Device that needs to be linked to its consumers |
|
* |
|
* This function looks at all the consumer fwnodes of @dev and creates device |
|
* links between the consumer device and @dev (supplier). |
|
* |
|
* If the consumer device has not been added yet, then this function creates a |
|
* SYNC_STATE_ONLY link between @dev (supplier) and the closest ancestor device |
|
* of the consumer fwnode. This is necessary to make sure @dev doesn't get a |
|
* sync_state() callback before the real consumer device gets to be added and |
|
* then probed. |
|
* |
|
* Once device links are created from the real consumer to @dev (supplier), the |
|
* fwnode links are deleted. |
|
*/ |
|
static void __fw_devlink_link_to_consumers(struct device *dev) |
|
{ |
|
struct fwnode_handle *fwnode = dev->fwnode; |
|
struct fwnode_link *link, *tmp; |
|
|
|
list_for_each_entry_safe(link, tmp, &fwnode->consumers, s_hook) { |
|
u32 dl_flags = fw_devlink_get_flags(); |
|
struct device *con_dev; |
|
bool own_link = true; |
|
int ret; |
|
|
|
con_dev = get_dev_from_fwnode(link->consumer); |
|
/* |
|
* If consumer device is not available yet, make a "proxy" |
|
* SYNC_STATE_ONLY link from the consumer's parent device to |
|
* the supplier device. This is necessary to make sure the |
|
* supplier doesn't get a sync_state() callback before the real |
|
* consumer can create a device link to the supplier. |
|
* |
|
* This proxy link step is needed to handle the case where the |
|
* consumer's parent device is added before the supplier. |
|
*/ |
|
if (!con_dev) { |
|
con_dev = fwnode_get_next_parent_dev(link->consumer); |
|
/* |
|
* However, if the consumer's parent device is also the |
|
* parent of the supplier, don't create a |
|
* consumer-supplier link from the parent to its child |
|
* device. Such a dependency is impossible. |
|
*/ |
|
if (con_dev && |
|
fwnode_is_ancestor_of(con_dev->fwnode, fwnode)) { |
|
put_device(con_dev); |
|
con_dev = NULL; |
|
} else { |
|
own_link = false; |
|
dl_flags = FW_DEVLINK_FLAGS_PERMISSIVE; |
|
} |
|
} |
|
|
|
if (!con_dev) |
|
continue; |
|
|
|
ret = fw_devlink_create_devlink(con_dev, fwnode, dl_flags); |
|
put_device(con_dev); |
|
if (!own_link || ret == -EAGAIN) |
|
continue; |
|
|
|
list_del(&link->s_hook); |
|
list_del(&link->c_hook); |
|
kfree(link); |
|
} |
|
} |
|
|
|
/** |
|
* __fw_devlink_link_to_suppliers - Create device links to suppliers of a device |
|
* @dev - The consumer device that needs to be linked to its suppliers |
|
* @fwnode - Root of the fwnode tree that is used to create device links |
|
* |
|
* This function looks at all the supplier fwnodes of fwnode tree rooted at |
|
* @fwnode and creates device links between @dev (consumer) and all the |
|
* supplier devices of the entire fwnode tree at @fwnode. |
|
* |
|
* The function creates normal (non-SYNC_STATE_ONLY) device links between @dev |
|
* and the real suppliers of @dev. Once these device links are created, the |
|
* fwnode links are deleted. When such device links are successfully created, |
|
* this function is called recursively on those supplier devices. This is |
|
* needed to detect and break some invalid cycles in fwnode links. See |
|
* fw_devlink_create_devlink() for more details. |
|
* |
|
* In addition, it also looks at all the suppliers of the entire fwnode tree |
|
* because some of the child devices of @dev that have not been added yet |
|
* (because @dev hasn't probed) might already have their suppliers added to |
|
* driver core. So, this function creates SYNC_STATE_ONLY device links between |
|
* @dev (consumer) and these suppliers to make sure they don't execute their |
|
* sync_state() callbacks before these child devices have a chance to create |
|
* their device links. The fwnode links that correspond to the child devices |
|
* aren't delete because they are needed later to create the device links |
|
* between the real consumer and supplier devices. |
|
*/ |
|
static void __fw_devlink_link_to_suppliers(struct device *dev, |
|
struct fwnode_handle *fwnode) |
|
{ |
|
bool own_link = (dev->fwnode == fwnode); |
|
struct fwnode_link *link, *tmp; |
|
struct fwnode_handle *child = NULL; |
|
u32 dl_flags; |
|
|
|
if (own_link) |
|
dl_flags = fw_devlink_get_flags(); |
|
else |
|
dl_flags = FW_DEVLINK_FLAGS_PERMISSIVE; |
|
|
|
list_for_each_entry_safe(link, tmp, &fwnode->suppliers, c_hook) { |
|
int ret; |
|
struct device *sup_dev; |
|
struct fwnode_handle *sup = link->supplier; |
|
|
|
ret = fw_devlink_create_devlink(dev, sup, dl_flags); |
|
if (!own_link || ret == -EAGAIN) |
|
continue; |
|
|
|
list_del(&link->s_hook); |
|
list_del(&link->c_hook); |
|
kfree(link); |
|
|
|
/* If no device link was created, nothing more to do. */ |
|
if (ret) |
|
continue; |
|
|
|
/* |
|
* If a device link was successfully created to a supplier, we |
|
* now need to try and link the supplier to all its suppliers. |
|
* |
|
* This is needed to detect and delete false dependencies in |
|
* fwnode links that haven't been converted to a device link |
|
* yet. See comments in fw_devlink_create_devlink() for more |
|
* details on the false dependency. |
|
* |
|
* Without deleting these false dependencies, some devices will |
|
* never probe because they'll keep waiting for their false |
|
* dependency fwnode links to be converted to device links. |
|
*/ |
|
sup_dev = get_dev_from_fwnode(sup); |
|
__fw_devlink_link_to_suppliers(sup_dev, sup_dev->fwnode); |
|
put_device(sup_dev); |
|
} |
|
|
|
/* |
|
* Make "proxy" SYNC_STATE_ONLY device links to represent the needs of |
|
* all the descendants. This proxy link step is needed to handle the |
|
* case where the supplier is added before the consumer's parent device |
|
* (@dev). |
|
*/ |
|
while ((child = fwnode_get_next_available_child_node(fwnode, child))) |
|
__fw_devlink_link_to_suppliers(dev, child); |
|
} |
|
|
|
static void fw_devlink_link_device(struct device *dev) |
|
{ |
|
struct fwnode_handle *fwnode = dev->fwnode; |
|
|
|
if (!fw_devlink_flags) |
|
return; |
|
|
|
fw_devlink_parse_fwtree(fwnode); |
|
|
|
mutex_lock(&fwnode_link_lock); |
|
__fw_devlink_link_to_consumers(dev); |
|
__fw_devlink_link_to_suppliers(dev, fwnode); |
|
mutex_unlock(&fwnode_link_lock); |
|
} |
|
|
|
/* Device links support end. */ |
|
|
|
int (*platform_notify)(struct device *dev) = NULL; |
|
int (*platform_notify_remove)(struct device *dev) = NULL; |
|
static struct kobject *dev_kobj; |
|
struct kobject *sysfs_dev_char_kobj; |
|
struct kobject *sysfs_dev_block_kobj; |
|
|
|
static DEFINE_MUTEX(device_hotplug_lock); |
|
|
|
void lock_device_hotplug(void) |
|
{ |
|
mutex_lock(&device_hotplug_lock); |
|
} |
|
|
|
void unlock_device_hotplug(void) |
|
{ |
|
mutex_unlock(&device_hotplug_lock); |
|
} |
|
|
|
int lock_device_hotplug_sysfs(void) |
|
{ |
|
if (mutex_trylock(&device_hotplug_lock)) |
|
return 0; |
|
|
|
/* Avoid busy looping (5 ms of sleep should do). */ |
|
msleep(5); |
|
return restart_syscall(); |
|
} |
|
|
|
#ifdef CONFIG_BLOCK |
|
static inline int device_is_not_partition(struct device *dev) |
|
{ |
|
return !(dev->type == &part_type); |
|
} |
|
#else |
|
static inline int device_is_not_partition(struct device *dev) |
|
{ |
|
return 1; |
|
} |
|
#endif |
|
|
|
static int |
|
device_platform_notify(struct device *dev, enum kobject_action action) |
|
{ |
|
int ret; |
|
|
|
ret = acpi_platform_notify(dev, action); |
|
if (ret) |
|
return ret; |
|
|
|
ret = software_node_notify(dev, action); |
|
if (ret) |
|
return ret; |
|
|
|
if (platform_notify && action == KOBJ_ADD) |
|
platform_notify(dev); |
|
else if (platform_notify_remove && action == KOBJ_REMOVE) |
|
platform_notify_remove(dev); |
|
return 0; |
|
} |
|
|
|
/** |
|
* dev_driver_string - Return a device's driver name, if at all possible |
|
* @dev: struct device to get the name of |
|
* |
|
* Will return the device's driver's name if it is bound to a device. If |
|
* the device is not bound to a driver, it will return the name of the bus |
|
* it is attached to. If it is not attached to a bus either, an empty |
|
* string will be returned. |
|
*/ |
|
const char *dev_driver_string(const struct device *dev) |
|
{ |
|
struct device_driver *drv; |
|
|
|
/* dev->driver can change to NULL underneath us because of unbinding, |
|
* so be careful about accessing it. dev->bus and dev->class should |
|
* never change once they are set, so they don't need special care. |
|
*/ |
|
drv = READ_ONCE(dev->driver); |
|
return drv ? drv->name : dev_bus_name(dev); |
|
} |
|
EXPORT_SYMBOL(dev_driver_string); |
|
|
|
#define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr) |
|
|
|
static ssize_t dev_attr_show(struct kobject *kobj, struct attribute *attr, |
|
char *buf) |
|
{ |
|
struct device_attribute *dev_attr = to_dev_attr(attr); |
|
struct device *dev = kobj_to_dev(kobj); |
|
ssize_t ret = -EIO; |
|
|
|
if (dev_attr->show) |
|
ret = dev_attr->show(dev, dev_attr, buf); |
|
if (ret >= (ssize_t)PAGE_SIZE) { |
|
printk("dev_attr_show: %pS returned bad count\n", |
|
dev_attr->show); |
|
} |
|
return ret; |
|
} |
|
|
|
static ssize_t dev_attr_store(struct kobject *kobj, struct attribute *attr, |
|
const char *buf, size_t count) |
|
{ |
|
struct device_attribute *dev_attr = to_dev_attr(attr); |
|
struct device *dev = kobj_to_dev(kobj); |
|
ssize_t ret = -EIO; |
|
|
|
if (dev_attr->store) |
|
ret = dev_attr->store(dev, dev_attr, buf, count); |
|
return ret; |
|
} |
|
|
|
static const struct sysfs_ops dev_sysfs_ops = { |
|
.show = dev_attr_show, |
|
.store = dev_attr_store, |
|
}; |
|
|
|
#define to_ext_attr(x) container_of(x, struct dev_ext_attribute, attr) |
|
|
|
ssize_t device_store_ulong(struct device *dev, |
|
struct device_attribute *attr, |
|
const char *buf, size_t size) |
|
{ |
|
struct dev_ext_attribute *ea = to_ext_attr(attr); |
|
int ret; |
|
unsigned long new; |
|
|
|
ret = kstrtoul(buf, 0, &new); |
|
if (ret) |
|
return ret; |
|
*(unsigned long *)(ea->var) = new; |
|
/* Always return full write size even if we didn't consume all */ |
|
return size; |
|
} |
|
EXPORT_SYMBOL_GPL(device_store_ulong); |
|
|
|
ssize_t device_show_ulong(struct device *dev, |
|
struct device_attribute *attr, |
|
char *buf) |
|
{ |
|
struct dev_ext_attribute *ea = to_ext_attr(attr); |
|
return sysfs_emit(buf, "%lx\n", *(unsigned long *)(ea->var)); |
|
} |
|
EXPORT_SYMBOL_GPL(device_show_ulong); |
|
|
|
ssize_t device_store_int(struct device *dev, |
|
struct device_attribute *attr, |
|
const char *buf, size_t size) |
|
{ |
|
struct dev_ext_attribute *ea = to_ext_attr(attr); |
|
int ret; |
|
long new; |
|
|
|
ret = kstrtol(buf, 0, &new); |
|
if (ret) |
|
return ret; |
|
|
|
if (new > INT_MAX || new < INT_MIN) |
|
return -EINVAL; |
|
*(int *)(ea->var) = new; |
|
/* Always return full write size even if we didn't consume all */ |
|
return size; |
|
} |
|
EXPORT_SYMBOL_GPL(device_store_int); |
|
|
|
ssize_t device_show_int(struct device *dev, |
|
struct device_attribute *attr, |
|
char *buf) |
|
{ |
|
struct dev_ext_attribute *ea = to_ext_attr(attr); |
|
|
|
return sysfs_emit(buf, "%d\n", *(int *)(ea->var)); |
|
} |
|
EXPORT_SYMBOL_GPL(device_show_int); |
|
|
|
ssize_t device_store_bool(struct device *dev, struct device_attribute *attr, |
|
const char *buf, size_t size) |
|
{ |
|
struct dev_ext_attribute *ea = to_ext_attr(attr); |
|
|
|
if (strtobool(buf, ea->var) < 0) |
|
return -EINVAL; |
|
|
|
return size; |
|
} |
|
EXPORT_SYMBOL_GPL(device_store_bool); |
|
|
|
ssize_t device_show_bool(struct device *dev, struct device_attribute *attr, |
|
char *buf) |
|
{ |
|
struct dev_ext_attribute *ea = to_ext_attr(attr); |
|
|
|
return sysfs_emit(buf, "%d\n", *(bool *)(ea->var)); |
|
} |
|
EXPORT_SYMBOL_GPL(device_show_bool); |
|
|
|
/** |
|
* device_release - free device structure. |
|
* @kobj: device's kobject. |
|
* |
|
* This is called once the reference count for the object |
|
* reaches 0. We forward the call to the device's release |
|
* method, which should handle actually freeing the structure. |
|
*/ |
|
static void device_release(struct kobject *kobj) |
|
{ |
|
struct device *dev = kobj_to_dev(kobj); |
|
struct device_private *p = dev->p; |
|
|
|
/* |
|
* Some platform devices are driven without driver attached |
|
* and managed resources may have been acquired. Make sure |
|
* all resources are released. |
|
* |
|
* Drivers still can add resources into device after device |
|
* is deleted but alive, so release devres here to avoid |
|
* possible memory leak. |
|
*/ |
|
devres_release_all(dev); |
|
|
|
kfree(dev->dma_range_map); |
|
|
|
if (dev->release) |
|
dev->release(dev); |
|
else if (dev->type && dev->type->release) |
|
dev->type->release(dev); |
|
else if (dev->class && dev->class->dev_release) |
|
dev->class->dev_release(dev); |
|
else |
|
WARN(1, KERN_ERR "Device '%s' does not have a release() function, it is broken and must be fixed. See Documentation/core-api/kobject.rst.\n", |
|
dev_name(dev)); |
|
kfree(p); |
|
} |
|
|
|
static const void *device_namespace(struct kobject *kobj) |
|
{ |
|
struct device *dev = kobj_to_dev(kobj); |
|
const void *ns = NULL; |
|
|
|
if (dev->class && dev->class->ns_type) |
|
ns = dev->class->namespace(dev); |
|
|
|
return ns; |
|
} |
|
|
|
static void device_get_ownership(struct kobject *kobj, kuid_t *uid, kgid_t *gid) |
|
{ |
|
struct device *dev = kobj_to_dev(kobj); |
|
|
|
if (dev->class && dev->class->get_ownership) |
|
dev->class->get_ownership(dev, uid, gid); |
|
} |
|
|
|
static struct kobj_type device_ktype = { |
|
.release = device_release, |
|
.sysfs_ops = &dev_sysfs_ops, |
|
.namespace = device_namespace, |
|
.get_ownership = device_get_ownership, |
|
}; |
|
|
|
|
|
static int dev_uevent_filter(struct kset *kset, struct kobject *kobj) |
|
{ |
|
struct kobj_type *ktype = get_ktype(kobj); |
|
|
|
if (ktype == &device_ktype) { |
|
struct device *dev = kobj_to_dev(kobj); |
|
if (dev->bus) |
|
return 1; |
|
if (dev->class) |
|
return 1; |
|
} |
|
return 0; |
|
} |
|
|
|
static const char *dev_uevent_name(struct kset *kset, struct kobject *kobj) |
|
{ |
|
struct device *dev = kobj_to_dev(kobj); |
|
|
|
if (dev->bus) |
|
return dev->bus->name; |
|
if (dev->class) |
|
return dev->class->name; |
|
return NULL; |
|
} |
|
|
|
static int dev_uevent(struct kset *kset, struct kobject *kobj, |
|
struct kobj_uevent_env *env) |
|
{ |
|
struct device *dev = kobj_to_dev(kobj); |
|
int retval = 0; |
|
|
|
/* add device node properties if present */ |
|
if (MAJOR(dev->devt)) { |
|
const char *tmp; |
|
const char *name; |
|
umode_t mode = 0; |
|
kuid_t uid = GLOBAL_ROOT_UID; |
|
kgid_t gid = GLOBAL_ROOT_GID; |
|
|
|
add_uevent_var(env, "MAJOR=%u", MAJOR(dev->devt)); |
|
add_uevent_var(env, "MINOR=%u", MINOR(dev->devt)); |
|
name = device_get_devnode(dev, &mode, &uid, &gid, &tmp); |
|
if (name) { |
|
add_uevent_var(env, "DEVNAME=%s", name); |
|
if (mode) |
|
add_uevent_var(env, "DEVMODE=%#o", mode & 0777); |
|
if (!uid_eq(uid, GLOBAL_ROOT_UID)) |
|
add_uevent_var(env, "DEVUID=%u", from_kuid(&init_user_ns, uid)); |
|
if (!gid_eq(gid, GLOBAL_ROOT_GID)) |
|
add_uevent_var(env, "DEVGID=%u", from_kgid(&init_user_ns, gid)); |
|
kfree(tmp); |
|
} |
|
} |
|
|
|
if (dev->type && dev->type->name) |
|
add_uevent_var(env, "DEVTYPE=%s", dev->type->name); |
|
|
|
if (dev->driver) |
|
add_uevent_var(env, "DRIVER=%s", dev->driver->name); |
|
|
|
/* Add common DT information about the device */ |
|
of_device_uevent(dev, env); |
|
|
|
/* have the bus specific function add its stuff */ |
|
if (dev->bus && dev->bus->uevent) { |
|
retval = dev->bus->uevent(dev, env); |
|
if (retval) |
|
pr_debug("device: '%s': %s: bus uevent() returned %d\n", |
|
dev_name(dev), __func__, retval); |
|
} |
|
|
|
/* have the class specific function add its stuff */ |
|
if (dev->class && dev->class->dev_uevent) { |
|
retval = dev->class->dev_uevent(dev, env); |
|
if (retval) |
|
pr_debug("device: '%s': %s: class uevent() " |
|
"returned %d\n", dev_name(dev), |
|
__func__, retval); |
|
} |
|
|
|
/* have the device type specific function add its stuff */ |
|
if (dev->type && dev->type->uevent) { |
|
retval = dev->type->uevent(dev, env); |
|
if (retval) |
|
pr_debug("device: '%s': %s: dev_type uevent() " |
|
"returned %d\n", dev_name(dev), |
|
__func__, retval); |
|
} |
|
|
|
return retval; |
|
} |
|
|
|
static const struct kset_uevent_ops device_uevent_ops = { |
|
.filter = dev_uevent_filter, |
|
.name = dev_uevent_name, |
|
.uevent = dev_uevent, |
|
}; |
|
|
|
static ssize_t uevent_show(struct device *dev, struct device_attribute *attr, |
|
char *buf) |
|
{ |
|
struct kobject *top_kobj; |
|
struct kset *kset; |
|
struct kobj_uevent_env *env = NULL; |
|
int i; |
|
int len = 0; |
|
int retval; |
|
|
|
/* search the kset, the device belongs to */ |
|
top_kobj = &dev->kobj; |
|
while (!top_kobj->kset && top_kobj->parent) |
|
top_kobj = top_kobj->parent; |
|
if (!top_kobj->kset) |
|
goto out; |
|
|
|
kset = top_kobj->kset; |
|
if (!kset->uevent_ops || !kset->uevent_ops->uevent) |
|
goto out; |
|
|
|
/* respect filter */ |
|
if (kset->uevent_ops && kset->uevent_ops->filter) |
|
if (!kset->uevent_ops->filter(kset, &dev->kobj)) |
|
goto out; |
|
|
|
env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL); |
|
if (!env) |
|
return -ENOMEM; |
|
|
|
/* let the kset specific function add its keys */ |
|
retval = kset->uevent_ops->uevent(kset, &dev->kobj, env); |
|
if (retval) |
|
goto out; |
|
|
|
/* copy keys to file */ |
|
for (i = 0; i < env->envp_idx; i++) |
|
len += sysfs_emit_at(buf, len, "%s\n", env->envp[i]); |
|
out: |
|
kfree(env); |
|
return len; |
|
} |
|
|
|
static ssize_t uevent_store(struct device *dev, struct device_attribute *attr, |
|
const char *buf, size_t count) |
|
{ |
|
int rc; |
|
|
|
rc = kobject_synth_uevent(&dev->kobj, buf, count); |
|
|
|
if (rc) { |
|
dev_err(dev, "uevent: failed to send synthetic uevent\n"); |
|
return rc; |
|
} |
|
|
|
return count; |
|
} |
|
static DEVICE_ATTR_RW(uevent); |
|
|
|
static ssize_t online_show(struct device *dev, struct device_attribute *attr, |
|
char *buf) |
|
{ |
|
bool val; |
|
|
|
device_lock(dev); |
|
val = !dev->offline; |
|
device_unlock(dev); |
|
return sysfs_emit(buf, "%u\n", val); |
|
} |
|
|
|
static ssize_t online_store(struct device *dev, struct device_attribute *attr, |
|
const char *buf, size_t count) |
|
{ |
|
bool val; |
|
int ret; |
|
|
|
ret = strtobool(buf, &val); |
|
if (ret < 0) |
|
return ret; |
|
|
|
ret = lock_device_hotplug_sysfs(); |
|
if (ret) |
|
return ret; |
|
|
|
ret = val ? device_online(dev) : device_offline(dev); |
|
unlock_device_hotplug(); |
|
return ret < 0 ? ret : count; |
|
} |
|
static DEVICE_ATTR_RW(online); |
|
|
|
int device_add_groups(struct device *dev, const struct attribute_group **groups) |
|
{ |
|
return sysfs_create_groups(&dev->kobj, groups); |
|
} |
|
EXPORT_SYMBOL_GPL(device_add_groups); |
|
|
|
void device_remove_groups(struct device *dev, |
|
const struct attribute_group **groups) |
|
{ |
|
sysfs_remove_groups(&dev->kobj, groups); |
|
} |
|
EXPORT_SYMBOL_GPL(device_remove_groups); |
|
|
|
union device_attr_group_devres { |
|
const struct attribute_group *group; |
|
const struct attribute_group **groups; |
|
}; |
|
|
|
static int devm_attr_group_match(struct device *dev, void *res, void *data) |
|
{ |
|
return ((union device_attr_group_devres *)res)->group == data; |
|
} |
|
|
|
static void devm_attr_group_remove(struct device *dev, void *res) |
|
{ |
|
union device_attr_group_devres *devres = res; |
|
const struct attribute_group *group = devres->group; |
|
|
|
dev_dbg(dev, "%s: removing group %p\n", __func__, group); |
|
sysfs_remove_group(&dev->kobj, group); |
|
} |
|
|
|
static void devm_attr_groups_remove(struct device *dev, void *res) |
|
{ |
|
union device_attr_group_devres *devres = res; |
|
const struct attribute_group **groups = devres->groups; |
|
|
|
dev_dbg(dev, "%s: removing groups %p\n", __func__, groups); |
|
sysfs_remove_groups(&dev->kobj, groups); |
|
} |
|
|
|
/** |
|
* devm_device_add_group - given a device, create a managed attribute group |
|
* @dev: The device to create the group for |
|
* @grp: The attribute group to create |
|
* |
|
* This function creates a group for the first time. It will explicitly |
|
* warn and error if any of the attribute files being created already exist. |
|
* |
|
* Returns 0 on success or error code on failure. |
|
*/ |
|
int devm_device_add_group(struct device *dev, const struct attribute_group *grp) |
|
{ |
|
union device_attr_group_devres *devres; |
|
int error; |
|
|
|
devres = devres_alloc(devm_attr_group_remove, |
|
sizeof(*devres), GFP_KERNEL); |
|
if (!devres) |
|
return -ENOMEM; |
|
|
|
error = sysfs_create_group(&dev->kobj, grp); |
|
if (error) { |
|
devres_free(devres); |
|
return error; |
|
} |
|
|
|
devres->group = grp; |
|
devres_add(dev, devres); |
|
return 0; |
|
} |
|
EXPORT_SYMBOL_GPL(devm_device_add_group); |
|
|
|
/** |
|
* devm_device_remove_group: remove a managed group from a device |
|
* @dev: device to remove the group from |
|
* @grp: group to remove |
|
* |
|
* This function removes a group of attributes from a device. The attributes |
|
* previously have to have been created for this group, otherwise it will fail. |
|
*/ |
|
void devm_device_remove_group(struct device *dev, |
|
const struct attribute_group *grp) |
|
{ |
|
WARN_ON(devres_release(dev, devm_attr_group_remove, |
|
devm_attr_group_match, |
|
/* cast away const */ (void *)grp)); |
|
} |
|
EXPORT_SYMBOL_GPL(devm_device_remove_group); |
|
|
|
/** |
|
* devm_device_add_groups - create a bunch of managed attribute groups |
|
* @dev: The device to create the group for |
|
* @groups: The attribute groups to create, NULL terminated |
|
* |
|
* This function creates a bunch of managed attribute groups. If an error |
|
* occurs when creating a group, all previously created groups will be |
|
* removed, unwinding everything back to the original state when this |
|
* function was called. It will explicitly warn and error if any of the |
|
* attribute files being created already exist. |
|
* |
|
* Returns 0 on success or error code from sysfs_create_group on failure. |
|
*/ |
|
int devm_device_add_groups(struct device *dev, |
|
const struct attribute_group **groups) |
|
{ |
|
union device_attr_group_devres *devres; |
|
int error; |
|
|
|
devres = devres_alloc(devm_attr_groups_remove, |
|
sizeof(*devres), GFP_KERNEL); |
|
if (!devres) |
|
return -ENOMEM; |
|
|
|
error = sysfs_create_groups(&dev->kobj, groups); |
|
if (error) { |
|
devres_free(devres); |
|
return error; |
|
} |
|
|
|
devres->groups = groups; |
|
devres_add(dev, devres); |
|
return 0; |
|
} |
|
EXPORT_SYMBOL_GPL(devm_device_add_groups); |
|
|
|
/** |
|
* devm_device_remove_groups - remove a list of managed groups |
|
* |
|
* @dev: The device for the groups to be removed from |
|
* @groups: NULL terminated list of groups to be removed |
|
* |
|
* If groups is not NULL, remove the specified groups from the device. |
|
*/ |
|
void devm_device_remove_groups(struct device *dev, |
|
const struct attribute_group **groups) |
|
{ |
|
WARN_ON(devres_release(dev, devm_attr_groups_remove, |
|
devm_attr_group_match, |
|
/* cast away const */ (void *)groups)); |
|
} |
|
EXPORT_SYMBOL_GPL(devm_device_remove_groups); |
|
|
|
static int device_add_attrs(struct device *dev) |
|
{ |
|
struct class *class = dev->class; |
|
const struct device_type *type = dev->type; |
|
int error; |
|
|
|
if (class) { |
|
error = device_add_groups(dev, class->dev_groups); |
|
if (error) |
|
return error; |
|
} |
|
|
|
if (type) { |
|
error = device_add_groups(dev, type->groups); |
|
if (error) |
|
goto err_remove_class_groups; |
|
} |
|
|
|
error = device_add_groups(dev, dev->groups); |
|
if (error) |
|
goto err_remove_type_groups; |
|
|
|
if (device_supports_offline(dev) && !dev->offline_disabled) { |
|
error = device_create_file(dev, &dev_attr_online); |
|
if (error) |
|
goto err_remove_dev_groups; |
|
} |
|
|
|
if (fw_devlink_flags && !fw_devlink_is_permissive() && dev->fwnode) { |
|
error = device_create_file(dev, &dev_attr_waiting_for_supplier); |
|
if (error) |
|
goto err_remove_dev_online; |
|
} |
|
|
|
return 0; |
|
|
|
err_remove_dev_online: |
|
device_remove_file(dev, &dev_attr_online); |
|
err_remove_dev_groups: |
|
device_remove_groups(dev, dev->groups); |
|
err_remove_type_groups: |
|
if (type) |
|
device_remove_groups(dev, type->groups); |
|
err_remove_class_groups: |
|
if (class) |
|
device_remove_groups(dev, class->dev_groups); |
|
|
|
return error; |
|
} |
|
|
|
static void device_remove_attrs(struct device *dev) |
|
{ |
|
struct class *class = dev->class; |
|
const struct device_type *type = dev->type; |
|
|
|
device_remove_file(dev, &dev_attr_waiting_for_supplier); |
|
device_remove_file(dev, &dev_attr_online); |
|
device_remove_groups(dev, dev->groups); |
|
|
|
if (type) |
|
device_remove_groups(dev, type->groups); |
|
|
|
if (class) |
|
device_remove_groups(dev, class->dev_groups); |
|
} |
|
|
|
static ssize_t dev_show(struct device *dev, struct device_attribute *attr, |
|
char *buf) |
|
{ |
|
return print_dev_t(buf, dev->devt); |
|
} |
|
static DEVICE_ATTR_RO(dev); |
|
|
|
/* /sys/devices/ */ |
|
struct kset *devices_kset; |
|
|
|
/** |
|
* devices_kset_move_before - Move device in the devices_kset's list. |
|
* @deva: Device to move. |
|
* @devb: Device @deva should come before. |
|
*/ |
|
static void devices_kset_move_before(struct device *deva, struct device *devb) |
|
{ |
|
if (!devices_kset) |
|
return; |
|
pr_debug("devices_kset: Moving %s before %s\n", |
|
dev_name(deva), dev_name(devb)); |
|
spin_lock(&devices_kset->list_lock); |
|
list_move_tail(&deva->kobj.entry, &devb->kobj.entry); |
|
spin_unlock(&devices_kset->list_lock); |
|
} |
|
|
|
/** |
|
* devices_kset_move_after - Move device in the devices_kset's list. |
|
* @deva: Device to move |
|
* @devb: Device @deva should come after. |
|
*/ |
|
static void devices_kset_move_after(struct device *deva, struct device *devb) |
|
{ |
|
if (!devices_kset) |
|
return; |
|
pr_debug("devices_kset: Moving %s after %s\n", |
|
dev_name(deva), dev_name(devb)); |
|
spin_lock(&devices_kset->list_lock); |
|
list_move(&deva->kobj.entry, &devb->kobj.entry); |
|
spin_unlock(&devices_kset->list_lock); |
|
} |
|
|
|
/** |
|
* devices_kset_move_last - move the device to the end of devices_kset's list. |
|
* @dev: device to move |
|
*/ |
|
void devices_kset_move_last(struct device *dev) |
|
{ |
|
if (!devices_kset) |
|
return; |
|
pr_debug("devices_kset: Moving %s to end of list\n", dev_name(dev)); |
|
spin_lock(&devices_kset->list_lock); |
|
list_move_tail(&dev->kobj.entry, &devices_kset->list); |
|
spin_unlock(&devices_kset->list_lock); |
|
} |
|
|
|
/** |
|
* device_create_file - create sysfs attribute file for device. |
|
* @dev: device. |
|
* @attr: device attribute descriptor. |
|
*/ |
|
int device_create_file(struct device *dev, |
|
const struct device_attribute *attr) |
|
{ |
|
int error = 0; |
|
|
|
if (dev) { |
|
WARN(((attr->attr.mode & S_IWUGO) && !attr->store), |
|
"Attribute %s: write permission without 'store'\n", |
|
attr->attr.name); |
|
WARN(((attr->attr.mode & S_IRUGO) && !attr->show), |
|
"Attribute %s: read permission without 'show'\n", |
|
attr->attr.name); |
|
error = sysfs_create_file(&dev->kobj, &attr->attr); |
|
} |
|
|
|
return error; |
|
} |
|
EXPORT_SYMBOL_GPL(device_create_file); |
|
|
|
/** |
|
* device_remove_file - remove sysfs attribute file. |
|
* @dev: device. |
|
* @attr: device attribute descriptor. |
|
*/ |
|
void device_remove_file(struct device *dev, |
|
const struct device_attribute *attr) |
|
{ |
|
if (dev) |
|
sysfs_remove_file(&dev->kobj, &attr->attr); |
|
} |
|
EXPORT_SYMBOL_GPL(device_remove_file); |
|
|
|
/** |
|
* device_remove_file_self - remove sysfs attribute file from its own method. |
|
* @dev: device. |
|
* @attr: device attribute descriptor. |
|
* |
|
* See kernfs_remove_self() for details. |
|
*/ |
|
bool device_remove_file_self(struct device *dev, |
|
const struct device_attribute *attr) |
|
{ |
|
if (dev) |
|
return sysfs_remove_file_self(&dev->kobj, &attr->attr); |
|
else |
|
return false; |
|
} |
|
EXPORT_SYMBOL_GPL(device_remove_file_self); |
|
|
|
/** |
|
* device_create_bin_file - create sysfs binary attribute file for device. |
|
* @dev: device. |
|
* @attr: device binary attribute descriptor. |
|
*/ |
|
int device_create_bin_file(struct device *dev, |
|
const struct bin_attribute *attr) |
|
{ |
|
int error = -EINVAL; |
|
if (dev) |
|
error = sysfs_create_bin_file(&dev->kobj, attr); |
|
return error; |
|
} |
|
EXPORT_SYMBOL_GPL(device_create_bin_file); |
|
|
|
/** |
|
* device_remove_bin_file - remove sysfs binary attribute file |
|
* @dev: device. |
|
* @attr: device binary attribute descriptor. |
|
*/ |
|
void device_remove_bin_file(struct device *dev, |
|
const struct bin_attribute *attr) |
|
{ |
|
if (dev) |
|
sysfs_remove_bin_file(&dev->kobj, attr); |
|
} |
|
EXPORT_SYMBOL_GPL(device_remove_bin_file); |
|
|
|
static void klist_children_get(struct klist_node *n) |
|
{ |
|
struct device_private *p = to_device_private_parent(n); |
|
struct device *dev = p->device; |
|
|
|
get_device(dev); |
|
} |
|
|
|
static void klist_children_put(struct klist_node *n) |
|
{ |
|
struct device_private *p = to_device_private_parent(n); |
|
struct device *dev = p->device; |
|
|
|
put_device(dev); |
|
} |
|
|
|
/** |
|
* device_initialize - init device structure. |
|
* @dev: device. |
|
* |
|
* This prepares the device for use by other layers by initializing |
|
* its fields. |
|
* It is the first half of device_register(), if called by |
|
* that function, though it can also be called separately, so one |
|
* may use @dev's fields. In particular, get_device()/put_device() |
|
* may be used for reference counting of @dev after calling this |
|
* function. |
|
* |
|
* All fields in @dev must be initialized by the caller to 0, except |
|
* for those explicitly set to some other value. The simplest |
|
* approach is to use kzalloc() to allocate the structure containing |
|
* @dev. |
|
* |
|
* NOTE: Use put_device() to give up your reference instead of freeing |
|
* @dev directly once you have called this function. |
|
*/ |
|
void device_initialize(struct device *dev) |
|
{ |
|
dev->kobj.kset = devices_kset; |
|
kobject_init(&dev->kobj, &device_ktype); |
|
INIT_LIST_HEAD(&dev->dma_pools); |
|
mutex_init(&dev->mutex); |
|
#ifdef CONFIG_PROVE_LOCKING |
|
mutex_init(&dev->lockdep_mutex); |
|
#endif |
|
lockdep_set_novalidate_class(&dev->mutex); |
|
spin_lock_init(&dev->devres_lock); |
|
INIT_LIST_HEAD(&dev->devres_head); |
|
device_pm_init(dev); |
|
set_dev_node(dev, -1); |
|
#ifdef CONFIG_GENERIC_MSI_IRQ |
|
INIT_LIST_HEAD(&dev->msi_list); |
|
#endif |
|
INIT_LIST_HEAD(&dev->links.consumers); |
|
INIT_LIST_HEAD(&dev->links.suppliers); |
|
INIT_LIST_HEAD(&dev->links.defer_sync); |
|
dev->links.status = DL_DEV_NO_DRIVER; |
|
#if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE) || \ |
|
defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU) || \ |
|
defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL) |
|
dev->dma_coherent = dma_default_coherent; |
|
#endif |
|
} |
|
EXPORT_SYMBOL_GPL(device_initialize); |
|
|
|
struct kobject *virtual_device_parent(struct device *dev) |
|
{ |
|
static struct kobject *virtual_dir = NULL; |
|
|
|
if (!virtual_dir) |
|
virtual_dir = kobject_create_and_add("virtual", |
|
&devices_kset->kobj); |
|
|
|
return virtual_dir; |
|
} |
|
|
|
struct class_dir { |
|
struct kobject kobj; |
|
struct class *class; |
|
}; |
|
|
|
#define to_class_dir(obj) container_of(obj, struct class_dir, kobj) |
|
|
|
static void class_dir_release(struct kobject *kobj) |
|
{ |
|
struct class_dir *dir = to_class_dir(kobj); |
|
kfree(dir); |
|
} |
|
|
|
static const |
|
struct kobj_ns_type_operations *class_dir_child_ns_type(struct kobject *kobj) |
|
{ |
|
struct class_dir *dir = to_class_dir(kobj); |
|
return dir->class->ns_type; |
|
} |
|
|
|
static struct kobj_type class_dir_ktype = { |
|
.release = class_dir_release, |
|
.sysfs_ops = &kobj_sysfs_ops, |
|
.child_ns_type = class_dir_child_ns_type |
|
}; |
|
|
|
static struct kobject * |
|
class_dir_create_and_add(struct class *class, struct kobject *parent_kobj) |
|
{ |
|
struct class_dir *dir; |
|
int retval; |
|
|
|
dir = kzalloc(sizeof(*dir), GFP_KERNEL); |
|
if (!dir) |
|
return ERR_PTR(-ENOMEM); |
|
|
|
dir->class = class; |
|
kobject_init(&dir->kobj, &class_dir_ktype); |
|
|
|
dir->kobj.kset = &class->p->glue_dirs; |
|
|
|
retval = kobject_add(&dir->kobj, parent_kobj, "%s", class->name); |
|
if (retval < 0) { |
|
kobject_put(&dir->kobj); |
|
return ERR_PTR(retval); |
|
} |
|
return &dir->kobj; |
|
} |
|
|
|
static DEFINE_MUTEX(gdp_mutex); |
|
|
|
static struct kobject *get_device_parent(struct device *dev, |
|
struct device *parent) |
|
{ |
|
if (dev->class) { |
|
struct kobject *kobj = NULL; |
|
struct kobject *parent_kobj; |
|
struct kobject *k; |
|
|
|
#ifdef CONFIG_BLOCK |
|
/* block disks show up in /sys/block */ |
|
if (sysfs_deprecated && dev->class == &block_class) { |
|
if (parent && parent->class == &block_class) |
|
return &parent->kobj; |
|
return &block_class.p->subsys.kobj; |
|
} |
|
#endif |
|
|
|
/* |
|
* If we have no parent, we live in "virtual". |
|
* Class-devices with a non class-device as parent, live |
|
* in a "glue" directory to prevent namespace collisions. |
|
*/ |
|
if (parent == NULL) |
|
parent_kobj = virtual_device_parent(dev); |
|
else if (parent->class && !dev->class->ns_type) |
|
return &parent->kobj; |
|
else |
|
parent_kobj = &parent->kobj; |
|
|
|
mutex_lock(&gdp_mutex); |
|
|
|
/* find our class-directory at the parent and reference it */ |
|
spin_lock(&dev->class->p->glue_dirs.list_lock); |
|
list_for_each_entry(k, &dev->class->p->glue_dirs.list, entry) |
|
if (k->parent == parent_kobj) { |
|
kobj = kobject_get(k); |
|
break; |
|
} |
|
spin_unlock(&dev->class->p->glue_dirs.list_lock); |
|
if (kobj) { |
|
mutex_unlock(&gdp_mutex); |
|
return kobj; |
|
} |
|
|
|
/* or create a new class-directory at the parent device */ |
|
k = class_dir_create_and_add(dev->class, parent_kobj); |
|
/* do not emit an uevent for this simple "glue" directory */ |
|
mutex_unlock(&gdp_mutex); |
|
return k; |
|
} |
|
|
|
/* subsystems can specify a default root directory for their devices */ |
|
if (!parent && dev->bus && dev->bus->dev_root) |
|
return &dev->bus->dev_root->kobj; |
|
|
|
if (parent) |
|
return &parent->kobj; |
|
return NULL; |
|
} |
|
|
|
static inline bool live_in_glue_dir(struct kobject *kobj, |
|
struct device *dev) |
|
{ |
|
if (!kobj || !dev->class || |
|
kobj->kset != &dev->class->p->glue_dirs) |
|
return false; |
|
return true; |
|
} |
|
|
|
static inline struct kobject *get_glue_dir(struct device *dev) |
|
{ |
|
return dev->kobj.parent; |
|
} |
|
|
|
/* |
|
* make sure cleaning up dir as the last step, we need to make |
|
* sure .release handler of kobject is run with holding the |
|
* global lock |
|
*/ |
|
static void cleanup_glue_dir(struct device *dev, struct kobject *glue_dir) |
|
{ |
|
unsigned int ref; |
|
|
|
/* see if we live in a "glue" directory */ |
|
if (!live_in_glue_dir(glue_dir, dev)) |
|
return; |
|
|
|
mutex_lock(&gdp_mutex); |
|
/** |
|
* There is a race condition between removing glue directory |
|
* and adding a new device under the glue directory. |
|
* |
|
* CPU1: CPU2: |
|
* |
|
* device_add() |
|
* get_device_parent() |
|
* class_dir_create_and_add() |
|
* kobject_add_internal() |
|
* create_dir() // create glue_dir |
|
* |
|
* device_add() |
|
* get_device_parent() |
|
* kobject_get() // get glue_dir |
|
* |
|
* device_del() |
|
* cleanup_glue_dir() |
|
* kobject_del(glue_dir) |
|
* |
|
* kobject_add() |
|
* kobject_add_internal() |
|
* create_dir() // in glue_dir |
|
* sysfs_create_dir_ns() |
|
* kernfs_create_dir_ns(sd) |
|
* |
|
* sysfs_remove_dir() // glue_dir->sd=NULL |
|
* sysfs_put() // free glue_dir->sd |
|
* |
|
* // sd is freed |
|
* kernfs_new_node(sd) |
|
* kernfs_get(glue_dir) |
|
* kernfs_add_one() |
|
* kernfs_put() |
|
* |
|
* Before CPU1 remove last child device under glue dir, if CPU2 add |
|
* a new device under glue dir, the glue_dir kobject reference count |
|
* will be increase to 2 in kobject_get(k). And CPU2 has been called |
|
* kernfs_create_dir_ns(). Meanwhile, CPU1 call sysfs_remove_dir() |
|
* and sysfs_put(). This result in glue_dir->sd is freed. |
|
* |
|
* Then the CPU2 will see a stale "empty" but still potentially used |
|
* glue dir around in kernfs_new_node(). |
|
* |
|
* In order to avoid this happening, we also should make sure that |
|
* kernfs_node for glue_dir is released in CPU1 only when refcount |
|
* for glue_dir kobj is 1. |
|
*/ |
|
ref = kref_read(&glue_dir->kref); |
|
if (!kobject_has_children(glue_dir) && !--ref) |
|
kobject_del(glue_dir); |
|
kobject_put(glue_dir); |
|
mutex_unlock(&gdp_mutex); |
|
} |
|
|
|
static int device_add_class_symlinks(struct device *dev) |
|
{ |
|
struct device_node *of_node = dev_of_node(dev); |
|
int error; |
|
|
|
if (of_node) { |
|
error = sysfs_create_link(&dev->kobj, of_node_kobj(of_node), "of_node"); |
|
if (error) |
|
dev_warn(dev, "Error %d creating of_node link\n",error); |
|
/* An error here doesn't warrant bringing down the device */ |
|
} |
|
|
|
if (!dev->class) |
|
return 0; |
|
|
|
error = sysfs_create_link(&dev->kobj, |
|
&dev->class->p->subsys.kobj, |
|
"subsystem"); |
|
if (error) |
|
goto out_devnode; |
|
|
|
if (dev->parent && device_is_not_partition(dev)) { |
|
error = sysfs_create_link(&dev->kobj, &dev->parent->kobj, |
|
"device"); |
|
if (error) |
|
goto out_subsys; |
|
} |
|
|
|
#ifdef CONFIG_BLOCK |
|
/* /sys/block has directories and does not need symlinks */ |
|
if (sysfs_deprecated && dev->class == &block_class) |
|
return 0; |
|
#endif |
|
|
|
/* link in the class directory pointing to the device */ |
|
error = sysfs_create_link(&dev->class->p->subsys.kobj, |
|
&dev->kobj, dev_name(dev)); |
|
if (error) |
|
goto out_device; |
|
|
|
return 0; |
|
|
|
out_device: |
|
sysfs_remove_link(&dev->kobj, "device"); |
|
|
|
out_subsys: |
|
sysfs_remove_link(&dev->kobj, "subsystem"); |
|
out_devnode: |
|
sysfs_remove_link(&dev->kobj, "of_node"); |
|
return error; |
|
} |
|
|
|
static void device_remove_class_symlinks(struct device *dev) |
|
{ |
|
if (dev_of_node(dev)) |
|
sysfs_remove_link(&dev->kobj, "of_node"); |
|
|
|
if (!dev->class) |
|
return; |
|
|
|
if (dev->parent && device_is_not_partition(dev)) |
|
sysfs_remove_link(&dev->kobj, "device"); |
|
sysfs_remove_link(&dev->kobj, "subsystem"); |
|
#ifdef CONFIG_BLOCK |
|
if (sysfs_deprecated && dev->class == &block_class) |
|
return; |
|
#endif |
|
sysfs_delete_link(&dev->class->p->subsys.kobj, &dev->kobj, dev_name(dev)); |
|
} |
|
|
|
/** |
|
* dev_set_name - set a device name |
|
* @dev: device |
|
* @fmt: format string for the device's name |
|
*/ |
|
int dev_set_name(struct device *dev, const char *fmt, ...) |
|
{ |
|
va_list vargs; |
|
int err; |
|
|
|
va_start(vargs, fmt); |
|
err = kobject_set_name_vargs(&dev->kobj, fmt, vargs); |
|
va_end(vargs); |
|
return err; |
|
} |
|
EXPORT_SYMBOL_GPL(dev_set_name); |
|
|
|
/** |
|
* device_to_dev_kobj - select a /sys/dev/ directory for the device |
|
* @dev: device |
|
* |
|
* By default we select char/ for new entries. Setting class->dev_obj |
|
* to NULL prevents an entry from being created. class->dev_kobj must |
|
* be set (or cleared) before any devices are registered to the class |
|
* otherwise device_create_sys_dev_entry() and |
|
* device_remove_sys_dev_entry() will disagree about the presence of |
|
* the link. |
|
*/ |
|
static struct kobject *device_to_dev_kobj(struct device *dev) |
|
{ |
|
struct kobject *kobj; |
|
|
|
if (dev->class) |
|
kobj = dev->class->dev_kobj; |
|
else |
|
kobj = sysfs_dev_char_kobj; |
|
|
|
return kobj; |
|
} |
|
|
|
static int device_create_sys_dev_entry(struct device *dev) |
|
{ |
|
struct kobject *kobj = device_to_dev_kobj(dev); |
|
int error = 0; |
|
char devt_str[15]; |
|
|
|
if (kobj) { |
|
format_dev_t(devt_str, dev->devt); |
|
error = sysfs_create_link(kobj, &dev->kobj, devt_str); |
|
} |
|
|
|
return error; |
|
} |
|
|
|
static void device_remove_sys_dev_entry(struct device *dev) |
|
{ |
|
struct kobject *kobj = device_to_dev_kobj(dev); |
|
char devt_str[15]; |
|
|
|
if (kobj) { |
|
format_dev_t(devt_str, dev->devt); |
|
sysfs_remove_link(kobj, devt_str); |
|
} |
|
} |
|
|
|
static int device_private_init(struct device *dev) |
|
{ |
|
dev->p = kzalloc(sizeof(*dev->p), GFP_KERNEL); |
|
if (!dev->p) |
|
return -ENOMEM; |
|
dev->p->device = dev; |
|
klist_init(&dev->p->klist_children, klist_children_get, |
|
klist_children_put); |
|
INIT_LIST_HEAD(&dev->p->deferred_probe); |
|
return 0; |
|
} |
|
|
|
/** |
|
* device_add - add device to device hierarchy. |
|
* @dev: device. |
|
* |
|
* This is part 2 of device_register(), though may be called |
|
* separately _iff_ device_initialize() has been called separately. |
|
* |
|
* This adds @dev to the kobject hierarchy via kobject_add(), adds it |
|
* to the global and sibling lists for the device, then |
|
* adds it to the other relevant subsystems of the driver model. |
|
* |
|
* Do not call this routine or device_register() more than once for |
|
* any device structure. The driver model core is not designed to work |
|
* with devices that get unregistered and then spring back to life. |
|
* (Among other things, it's very hard to guarantee that all references |
|
* to the previous incarnation of @dev have been dropped.) Allocate |
|
* and register a fresh new struct device instead. |
|
* |
|
* NOTE: _Never_ directly free @dev after calling this function, even |
|
* if it returned an error! Always use put_device() to give up your |
|
* reference instead. |
|
* |
|
* Rule of thumb is: if device_add() succeeds, you should call |
|
* device_del() when you want to get rid of it. If device_add() has |
|
* *not* succeeded, use *only* put_device() to drop the reference |
|
* count. |
|
*/ |
|
int device_add(struct device *dev) |
|
{ |
|
struct device *parent; |
|
struct kobject *kobj; |
|
struct class_interface *class_intf; |
|
int error = -EINVAL; |
|
struct kobject *glue_dir = NULL; |
|
|
|
dev = get_device(dev); |
|
if (!dev) |
|
goto done; |
|
|
|
if (!dev->p) { |
|
error = device_private_init(dev); |
|
if (error) |
|
goto done; |
|
} |
|
|
|
/* |
|
* for statically allocated devices, which should all be converted |
|
* some day, we need to initialize the name. We prevent reading back |
|
* the name, and force the use of dev_name() |
|
*/ |
|
if (dev->init_name) { |
|
dev_set_name(dev, "%s", dev->init_name); |
|
dev->init_name = NULL; |
|
} |
|
|
|
/* subsystems can specify simple device enumeration */ |
|
if (!dev_name(dev) && dev->bus && dev->bus->dev_name) |
|
dev_set_name(dev, "%s%u", dev->bus->dev_name, dev->id); |
|
|
|
if (!dev_name(dev)) { |
|
error = -EINVAL; |
|
goto name_error; |
|
} |
|
|
|
pr_debug("device: '%s': %s\n", dev_name(dev), __func__); |
|
|
|
parent = get_device(dev->parent); |
|
kobj = get_device_parent(dev, parent); |
|
if (IS_ERR(kobj)) { |
|
error = PTR_ERR(kobj); |
|
goto parent_error; |
|
} |
|
if (kobj) |
|
dev->kobj.parent = kobj; |
|
|
|
/* use parent numa_node */ |
|
if (parent && (dev_to_node(dev) == NUMA_NO_NODE)) |
|
set_dev_node(dev, dev_to_node(parent)); |
|
|
|
/* first, register with generic layer. */ |
|
/* we require the name to be set before, and pass NULL */ |
|
error = kobject_add(&dev->kobj, dev->kobj.parent, NULL); |
|
if (error) { |
|
glue_dir = get_glue_dir(dev); |
|
goto Error; |
|
} |
|
|
|
/* notify platform of device entry */ |
|
error = device_platform_notify(dev, KOBJ_ADD); |
|
if (error) |
|
goto platform_error; |
|
|
|
error = device_create_file(dev, &dev_attr_uevent); |
|
if (error) |
|
goto attrError; |
|
|
|
error = device_add_class_symlinks(dev); |
|
if (error) |
|
goto SymlinkError; |
|
error = device_add_attrs(dev); |
|
if (error) |
|
goto AttrsError; |
|
error = bus_add_device(dev); |
|
if (error) |
|
goto BusError; |
|
error = dpm_sysfs_add(dev); |
|
if (error) |
|
goto DPMError; |
|
device_pm_add(dev); |
|
|
|
if (MAJOR(dev->devt)) { |
|
error = device_create_file(dev, &dev_attr_dev); |
|
if (error) |
|
goto DevAttrError; |
|
|
|
error = device_create_sys_dev_entry(dev); |
|
if (error) |
|
goto SysEntryError; |
|
|
|
devtmpfs_create_node(dev); |
|
} |
|
|
|
/* Notify clients of device addition. This call must come |
|
* after dpm_sysfs_add() and before kobject_uevent(). |
|
*/ |
|
if (dev->bus) |
|
blocking_notifier_call_chain(&dev->bus->p->bus_notifier, |
|
BUS_NOTIFY_ADD_DEVICE, dev); |
|
|
|
kobject_uevent(&dev->kobj, KOBJ_ADD); |
|
|
|
/* |
|
* Check if any of the other devices (consumers) have been waiting for |
|
* this device (supplier) to be added so that they can create a device |
|
* link to it. |
|
* |
|
* This needs to happen after device_pm_add() because device_link_add() |
|
* requires the supplier be registered before it's called. |
|
* |
|
* But this also needs to happen before bus_probe_device() to make sure |
|
* waiting consumers can link to it before the driver is bound to the |
|
* device and the driver sync_state callback is called for this device. |
|
*/ |
|
if (dev->fwnode && !dev->fwnode->dev) { |
|
dev->fwnode->dev = dev; |
|
fw_devlink_link_device(dev); |
|
} |
|
|
|
bus_probe_device(dev); |
|
if (parent) |
|
klist_add_tail(&dev->p->knode_parent, |
|
&parent->p->klist_children); |
|
|
|
if (dev->class) { |
|
mutex_lock(&dev->class->p->mutex); |
|
/* tie the class to the device */ |
|
klist_add_tail(&dev->p->knode_class, |
|
&dev->class->p->klist_devices); |
|
|
|
/* notify any interfaces that the device is here */ |
|
list_for_each_entry(class_intf, |
|
&dev->class->p->interfaces, node) |
|
if (class_intf->add_dev) |
|
class_intf->add_dev(dev, class_intf); |
|
mutex_unlock(&dev->class->p->mutex); |
|
} |
|
done: |
|
put_device(dev); |
|
return error; |
|
SysEntryError: |
|
if (MAJOR(dev->devt)) |
|
device_remove_file(dev, &dev_attr_dev); |
|
DevAttrError: |
|
device_pm_remove(dev); |
|
dpm_sysfs_remove(dev); |
|
DPMError: |
|
bus_remove_device(dev); |
|
BusError: |
|
device_remove_attrs(dev); |
|
AttrsError: |
|
device_remove_class_symlinks(dev); |
|
SymlinkError: |
|
device_remove_file(dev, &dev_attr_uevent); |
|
attrError: |
|
device_platform_notify(dev, KOBJ_REMOVE); |
|
platform_error: |
|
kobject_uevent(&dev->kobj, KOBJ_REMOVE); |
|
glue_dir = get_glue_dir(dev); |
|
kobject_del(&dev->kobj); |
|
Error: |
|
cleanup_glue_dir(dev, glue_dir); |
|
parent_error: |
|
put_device(parent); |
|
name_error: |
|
kfree(dev->p); |
|
dev->p = NULL; |
|
goto done; |
|
} |
|
EXPORT_SYMBOL_GPL(device_add); |
|
|
|
/** |
|
* device_register - register a device with the system. |
|
* @dev: pointer to the device structure |
|
* |
|
* This happens in two clean steps - initialize the device |
|
* and add it to the system. The two steps can be called |
|
* separately, but this is the easiest and most common. |
|
* I.e. you should only call the two helpers separately if |
|
* have a clearly defined need to use and refcount the device |
|
* before it is added to the hierarchy. |
|
* |
|
* For more information, see the kerneldoc for device_initialize() |
|
* and device_add(). |
|
* |
|
* NOTE: _Never_ directly free @dev after calling this function, even |
|
* if it returned an error! Always use put_device() to give up the |
|
* reference initialized in this function instead. |
|
*/ |
|
int device_register(struct device *dev) |
|
{ |
|
device_initialize(dev); |
|
return device_add(dev); |
|
} |
|
EXPORT_SYMBOL_GPL(device_register); |
|
|
|
/** |
|
* get_device - increment reference count for device. |
|
* @dev: device. |
|
* |
|
* This simply forwards the call to kobject_get(), though |
|
* we do take care to provide for the case that we get a NULL |
|
* pointer passed in. |
|
*/ |
|
struct device *get_device(struct device *dev) |
|
{ |
|
return dev ? kobj_to_dev(kobject_get(&dev->kobj)) : NULL; |
|
} |
|
EXPORT_SYMBOL_GPL(get_device); |
|
|
|
/** |
|
* put_device - decrement reference count. |
|
* @dev: device in question. |
|
*/ |
|
void put_device(struct device *dev) |
|
{ |
|
/* might_sleep(); */ |
|
if (dev) |
|
kobject_put(&dev->kobj); |
|
} |
|
EXPORT_SYMBOL_GPL(put_device); |
|
|
|
bool kill_device(struct device *dev) |
|
{ |
|
/* |
|
* Require the device lock and set the "dead" flag to guarantee that |
|
* the update behavior is consistent with the other bitfields near |
|
* it and that we cannot have an asynchronous probe routine trying |
|
* to run while we are tearing out the bus/class/sysfs from |
|
* underneath the device. |
|
*/ |
|
lockdep_assert_held(&dev->mutex); |
|
|
|
if (dev->p->dead) |
|
return false; |
|
dev->p->dead = true; |
|
return true; |
|
} |
|
EXPORT_SYMBOL_GPL(kill_device); |
|
|
|
/** |
|
* device_del - delete device from system. |
|
* @dev: device. |
|
* |
|
* This is the first part of the device unregistration |
|
* sequence. This removes the device from the lists we control |
|
* from here, has it removed from the other driver model |
|
* subsystems it was added to in device_add(), and removes it |
|
* from the kobject hierarchy. |
|
* |
|
* NOTE: this should be called manually _iff_ device_add() was |
|
* also called manually. |
|
*/ |
|
void device_del(struct device *dev) |
|
{ |
|
struct device *parent = dev->parent; |
|
struct kobject *glue_dir = NULL; |
|
struct class_interface *class_intf; |
|
unsigned int noio_flag; |
|
|
|
device_lock(dev); |
|
kill_device(dev); |
|
device_unlock(dev); |
|
|
|
if (dev->fwnode && dev->fwnode->dev == dev) |
|
dev->fwnode->dev = NULL; |
|
|
|
/* Notify clients of device removal. This call must come |
|
* before dpm_sysfs_remove(). |
|
*/ |
|
noio_flag = memalloc_noio_save(); |
|
if (dev->bus) |
|
blocking_notifier_call_chain(&dev->bus->p->bus_notifier, |
|
BUS_NOTIFY_DEL_DEVICE, dev); |
|
|
|
dpm_sysfs_remove(dev); |
|
if (parent) |
|
klist_del(&dev->p->knode_parent); |
|
if (MAJOR(dev->devt)) { |
|
devtmpfs_delete_node(dev); |
|
device_remove_sys_dev_entry(dev); |
|
device_remove_file(dev, &dev_attr_dev); |
|
} |
|
if (dev->class) { |
|
device_remove_class_symlinks(dev); |
|
|
|
mutex_lock(&dev->class->p->mutex); |
|
/* notify any interfaces that the device is now gone */ |
|
list_for_each_entry(class_intf, |
|
&dev->class->p->interfaces, node) |
|
if (class_intf->remove_dev) |
|
class_intf->remove_dev(dev, class_intf); |
|
/* remove the device from the class list */ |
|
klist_del(&dev->p->knode_class); |
|
mutex_unlock(&dev->class->p->mutex); |
|
} |
|
device_remove_file(dev, &dev_attr_uevent); |
|
device_remove_attrs(dev); |
|
bus_remove_device(dev); |
|
device_pm_remove(dev); |
|
driver_deferred_probe_del(dev); |
|
device_platform_notify(dev, KOBJ_REMOVE); |
|
device_remove_properties(dev); |
|
device_links_purge(dev); |
|
|
|
if (dev->bus) |
|
blocking_notifier_call_chain(&dev->bus->p->bus_notifier, |
|
BUS_NOTIFY_REMOVED_DEVICE, dev); |
|
kobject_uevent(&dev->kobj, KOBJ_REMOVE); |
|
glue_dir = get_glue_dir(dev); |
|
kobject_del(&dev->kobj); |
|
cleanup_glue_dir(dev, glue_dir); |
|
memalloc_noio_restore(noio_flag); |
|
put_device(parent); |
|
} |
|
EXPORT_SYMBOL_GPL(device_del); |
|
|
|
/** |
|
* device_unregister - unregister device from system. |
|
* @dev: device going away. |
|
* |
|
* We do this in two parts, like we do device_register(). First, |
|
* we remove it from all the subsystems with device_del(), then |
|
* we decrement the reference count via put_device(). If that |
|
* is the final reference count, the device will be cleaned up |
|
* via device_release() above. Otherwise, the structure will |
|
* stick around until the final reference to the device is dropped. |
|
*/ |
|
void device_unregister(struct device *dev) |
|
{ |
|
pr_debug("device: '%s': %s\n", dev_name(dev), __func__); |
|
device_del(dev); |
|
put_device(dev); |
|
} |
|
EXPORT_SYMBOL_GPL(device_unregister); |
|
|
|
static struct device *prev_device(struct klist_iter *i) |
|
{ |
|
struct klist_node *n = klist_prev(i); |
|
struct device *dev = NULL; |
|
struct device_private *p; |
|
|
|
if (n) { |
|
p = to_device_private_parent(n); |
|
dev = p->device; |
|
} |
|
return dev; |
|
} |
|
|
|
static struct device *next_device(struct klist_iter *i) |
|
{ |
|
struct klist_node *n = klist_next(i); |
|
struct device *dev = NULL; |
|
struct device_private *p; |
|
|
|
if (n) { |
|
p = to_device_private_parent(n); |
|
dev = p->device; |
|
} |
|
return dev; |
|
} |
|
|
|
/** |
|
* device_get_devnode - path of device node file |
|
* @dev: device |
|
* @mode: returned file access mode |
|
* @uid: returned file owner |
|
* @gid: returned file group |
|
* @tmp: possibly allocated string |
|
* |
|
* Return the relative path of a possible device node. |
|
* Non-default names may need to allocate a memory to compose |
|
* a name. This memory is returned in tmp and needs to be |
|
* freed by the caller. |
|
*/ |
|
const char *device_get_devnode(struct device *dev, |
|
umode_t *mode, kuid_t *uid, kgid_t *gid, |
|
const char **tmp) |
|
{ |
|
char *s; |
|
|
|
*tmp = NULL; |
|
|
|
/* the device type may provide a specific name */ |
|
if (dev->type && dev->type->devnode) |
|
*tmp = dev->type->devnode(dev, mode, uid, gid); |
|
if (*tmp) |
|
return *tmp; |
|
|
|
/* the class may provide a specific name */ |
|
if (dev->class && dev->class->devnode) |
|
*tmp = dev->class->devnode(dev, mode); |
|
if (*tmp) |
|
return *tmp; |
|
|
|
/* return name without allocation, tmp == NULL */ |
|
if (strchr(dev_name(dev), '!') == NULL) |
|
return dev_name(dev); |
|
|
|
/* replace '!' in the name with '/' */ |
|
s = kstrdup(dev_name(dev), GFP_KERNEL); |
|
if (!s) |
|
return NULL; |
|
strreplace(s, '!', '/'); |
|
return *tmp = s; |
|
} |
|
|
|
/** |
|
* device_for_each_child - device child iterator. |
|
* @parent: parent struct device. |
|
* @fn: function to be called for each device. |
|
* @data: data for the callback. |
|
* |
|
* Iterate over @parent's child devices, and call @fn for each, |
|
* passing it @data. |
|
* |
|
* We check the return of @fn each time. If it returns anything |
|
* other than 0, we break out and return that value. |
|
*/ |
|
int device_for_each_child(struct device *parent, void *data, |
|
int (*fn)(struct device *dev, void *data)) |
|
{ |
|
struct klist_iter i; |
|
struct device *child; |
|
int error = 0; |
|
|
|
if (!parent->p) |
|
return 0; |
|
|
|
klist_iter_init(&parent->p->klist_children, &i); |
|
while (!error && (child = next_device(&i))) |
|
error = fn(child, data); |
|
klist_iter_exit(&i); |
|
return error; |
|
} |
|
EXPORT_SYMBOL_GPL(device_for_each_child); |
|
|
|
/** |
|
* device_for_each_child_reverse - device child iterator in reversed order. |
|
* @parent: parent struct device. |
|
* @fn: function to be called for each device. |
|
* @data: data for the callback. |
|
* |
|
* Iterate over @parent's child devices, and call @fn for each, |
|
* passing it @data. |
|
* |
|
* We check the return of @fn each time. If it returns anything |
|
* other than 0, we break out and return that value. |
|
*/ |
|
int device_for_each_child_reverse(struct device *parent, void *data, |
|
int (*fn)(struct device *dev, void *data)) |
|
{ |
|
struct klist_iter i; |
|
struct device *child; |
|
int error = 0; |
|
|
|
if (!parent->p) |
|
return 0; |
|
|
|
klist_iter_init(&parent->p->klist_children, &i); |
|
while ((child = prev_device(&i)) && !error) |
|
error = fn(child, data); |
|
klist_iter_exit(&i); |
|
return error; |
|
} |
|
EXPORT_SYMBOL_GPL(device_for_each_child_reverse); |
|
|
|
/** |
|
* device_find_child - device iterator for locating a particular device. |
|
* @parent: parent struct device |
|
* @match: Callback function to check device |
|
* @data: Data to pass to match function |
|
* |
|
* This is similar to the device_for_each_child() function above, but it |
|
* returns a reference to a device that is 'found' for later use, as |
|
* determined by the @match callback. |
|
* |
|
* The callback should return 0 if the device doesn't match and non-zero |
|
* if it does. If the callback returns non-zero and a reference to the |
|
* current device can be obtained, this function will return to the caller |
|
* and not iterate over any more devices. |
|
* |
|
* NOTE: you will need to drop the reference with put_device() after use. |
|
*/ |
|
struct device *device_find_child(struct device *parent, void *data, |
|
int (*match)(struct device *dev, void *data)) |
|
{ |
|
struct klist_iter i; |
|
struct device *child; |
|
|
|
if (!parent) |
|
return NULL; |
|
|
|
klist_iter_init(&parent->p->klist_children, &i); |
|
while ((child = next_device(&i))) |
|
if (match(child, data) && get_device(child)) |
|
break; |
|
klist_iter_exit(&i); |
|
return child; |
|
} |
|
EXPORT_SYMBOL_GPL(device_find_child); |
|
|
|
/** |
|
* device_find_child_by_name - device iterator for locating a child device. |
|
* @parent: parent struct device |
|
* @name: name of the child device |
|
* |
|
* This is similar to the device_find_child() function above, but it |
|
* returns a reference to a device that has the name @name. |
|
* |
|
* NOTE: you will need to drop the reference with put_device() after use. |
|
*/ |
|
struct device *device_find_child_by_name(struct device *parent, |
|
const char *name) |
|
{ |
|
struct klist_iter i; |
|
struct device *child; |
|
|
|
if (!parent) |
|
return NULL; |
|
|
|
klist_iter_init(&parent->p->klist_children, &i); |
|
while ((child = next_device(&i))) |
|
if (sysfs_streq(dev_name(child), name) && get_device(child)) |
|
break; |
|
klist_iter_exit(&i); |
|
return child; |
|
} |
|
EXPORT_SYMBOL_GPL(device_find_child_by_name); |
|
|
|
int __init devices_init(void) |
|
{ |
|
devices_kset = kset_create_and_add("devices", &device_uevent_ops, NULL); |
|
if (!devices_kset) |
|
return -ENOMEM; |
|
dev_kobj = kobject_create_and_add("dev", NULL); |
|
if (!dev_kobj) |
|
goto dev_kobj_err; |
|
sysfs_dev_block_kobj = kobject_create_and_add("block", dev_kobj); |
|
if (!sysfs_dev_block_kobj) |
|
goto block_kobj_err; |
|
sysfs_dev_char_kobj = kobject_create_and_add("char", dev_kobj); |
|
if (!sysfs_dev_char_kobj) |
|
goto char_kobj_err; |
|
|
|
return 0; |
|
|
|
char_kobj_err: |
|
kobject_put(sysfs_dev_block_kobj); |
|
block_kobj_err: |
|
kobject_put(dev_kobj); |
|
dev_kobj_err: |
|
kset_unregister(devices_kset); |
|
return -ENOMEM; |
|
} |
|
|
|
static int device_check_offline(struct device *dev, void *not_used) |
|
{ |
|
int ret; |
|
|
|
ret = device_for_each_child(dev, NULL, device_check_offline); |
|
if (ret) |
|
return ret; |
|
|
|
return device_supports_offline(dev) && !dev->offline ? -EBUSY : 0; |
|
} |
|
|
|
/** |
|
* device_offline - Prepare the device for hot-removal. |
|
* @dev: Device to be put offline. |
|
* |
|
* Execute the device bus type's .offline() callback, if present, to prepare |
|
* the device for a subsequent hot-removal. If that succeeds, the device must |
|
* not be used until either it is removed or its bus type's .online() callback |
|
* is executed. |
|
* |
|
* Call under device_hotplug_lock. |
|
*/ |
|
int device_offline(struct device *dev) |
|
{ |
|
int ret; |
|
|
|
if (dev->offline_disabled) |
|
return -EPERM; |
|
|
|
ret = device_for_each_child(dev, NULL, device_check_offline); |
|
if (ret) |
|
return ret; |
|
|
|
device_lock(dev); |
|
if (device_supports_offline(dev)) { |
|
if (dev->offline) { |
|
ret = 1; |
|
} else { |
|
ret = dev->bus->offline(dev); |
|
if (!ret) { |
|
kobject_uevent(&dev->kobj, KOBJ_OFFLINE); |
|
dev->offline = true; |
|
} |
|
} |
|
} |
|
device_unlock(dev); |
|
|
|
return ret; |
|
} |
|
|
|
/** |
|
* device_online - Put the device back online after successful device_offline(). |
|
* @dev: Device to be put back online. |
|
* |
|
* If device_offline() has been successfully executed for @dev, but the device |
|
* has not been removed subsequently, execute its bus type's .online() callback |
|
* to indicate that the device can be used again. |
|
* |
|
* Call under device_hotplug_lock. |
|
*/ |
|
int device_online(struct device *dev) |
|
{ |
|
int ret = 0; |
|
|
|
device_lock(dev); |
|
if (device_supports_offline(dev)) { |
|
if (dev->offline) { |
|
ret = dev->bus->online(dev); |
|
if (!ret) { |
|
kobject_uevent(&dev->kobj, KOBJ_ONLINE); |
|
dev->offline = false; |
|
} |
|
} else { |
|
ret = 1; |
|
} |
|
} |
|
device_unlock(dev); |
|
|
|
return ret; |
|
} |
|
|
|
struct root_device { |
|
struct device dev; |
|
struct module *owner; |
|
}; |
|
|
|
static inline struct root_device *to_root_device(struct device *d) |
|
{ |
|
return container_of(d, struct root_device, dev); |
|
} |
|
|
|
static void root_device_release(struct device *dev) |
|
{ |
|
kfree(to_root_device(dev)); |
|
} |
|
|
|
/** |
|
* __root_device_register - allocate and register a root device |
|
* @name: root device name |
|
* @owner: owner module of the root device, usually THIS_MODULE |
|
* |
|
* This function allocates a root device and registers it |
|
* using device_register(). In order to free the returned |
|
* device, use root_device_unregister(). |
|
* |
|
* Root devices are dummy devices which allow other devices |
|
* to be grouped under /sys/devices. Use this function to |
|
* allocate a root device and then use it as the parent of |
|
* any device which should appear under /sys/devices/{name} |
|
* |
|
* The /sys/devices/{name} directory will also contain a |
|
* 'module' symlink which points to the @owner directory |
|
* in sysfs. |
|
* |
|
* Returns &struct device pointer on success, or ERR_PTR() on error. |
|
* |
|
* Note: You probably want to use root_device_register(). |
|
*/ |
|
struct device *__root_device_register(const char *name, struct module *owner) |
|
{ |
|
struct root_device *root; |
|
int err = -ENOMEM; |
|
|
|
root = kzalloc(sizeof(struct root_device), GFP_KERNEL); |
|
if (!root) |
|
return ERR_PTR(err); |
|
|
|
err = dev_set_name(&root->dev, "%s", name); |
|
if (err) { |
|
kfree(root); |
|
return ERR_PTR(err); |
|
} |
|
|
|
root->dev.release = root_device_release; |
|
|
|
err = device_register(&root->dev); |
|
if (err) { |
|
put_device(&root->dev); |
|
return ERR_PTR(err); |
|
} |
|
|
|
#ifdef CONFIG_MODULES /* gotta find a "cleaner" way to do this */ |
|
if (owner) { |
|
struct module_kobject *mk = &owner->mkobj; |
|
|
|
err = sysfs_create_link(&root->dev.kobj, &mk->kobj, "module"); |
|
if (err) { |
|
device_unregister(&root->dev); |
|
return ERR_PTR(err); |
|
} |
|
root->owner = owner; |
|
} |
|
#endif |
|
|
|
return &root->dev; |
|
} |
|
EXPORT_SYMBOL_GPL(__root_device_register); |
|
|
|
/** |
|
* root_device_unregister - unregister and free a root device |
|
* @dev: device going away |
|
* |
|
* This function unregisters and cleans up a device that was created by |
|
* root_device_register(). |
|
*/ |
|
void root_device_unregister(struct device *dev) |
|
{ |
|
struct root_device *root = to_root_device(dev); |
|
|
|
if (root->owner) |
|
sysfs_remove_link(&root->dev.kobj, "module"); |
|
|
|
device_unregister(dev); |
|
} |
|
EXPORT_SYMBOL_GPL(root_device_unregister); |
|
|
|
|
|
static void device_create_release(struct device *dev) |
|
{ |
|
pr_debug("device: '%s': %s\n", dev_name(dev), __func__); |
|
kfree(dev); |
|
} |
|
|
|
static __printf(6, 0) struct device * |
|
device_create_groups_vargs(struct class *class, struct device *parent, |
|
dev_t devt, void *drvdata, |
|
const struct attribute_group **groups, |
|
const char *fmt, va_list args) |
|
{ |
|
struct device *dev = NULL; |
|
int retval = -ENODEV; |
|
|
|
if (class == NULL || IS_ERR(class)) |
|
goto error; |
|
|
|
dev = kzalloc(sizeof(*dev), GFP_KERNEL); |
|
if (!dev) { |
|
retval = -ENOMEM; |
|
goto error; |
|
} |
|
|
|
device_initialize(dev); |
|
dev->devt = devt; |
|
dev->class = class; |
|
dev->parent = parent; |
|
dev->groups = groups; |
|
dev->release = device_create_release; |
|
dev_set_drvdata(dev, drvdata); |
|
|
|
retval = kobject_set_name_vargs(&dev->kobj, fmt, args); |
|
if (retval) |
|
goto error; |
|
|
|
retval = device_add(dev); |
|
if (retval) |
|
goto error; |
|
|
|
return dev; |
|
|
|
error: |
|
put_device(dev); |
|
return ERR_PTR(retval); |
|
} |
|
|
|
/** |
|
* device_create - creates a device and registers it with sysfs |
|
* @class: pointer to the struct class that this device should be registered to |
|
* @parent: pointer to the parent struct device of this new device, if any |
|
* @devt: the dev_t for the char device to be added |
|
* @drvdata: the data to be added to the device for callbacks |
|
* @fmt: string for the device's name |
|
* |
|
* This function can be used by char device classes. A struct device |
|
* will be created in sysfs, registered to the specified class. |
|
* |
|
* A "dev" file will be created, showing the dev_t for the device, if |
|
* the dev_t is not 0,0. |
|
* If a pointer to a parent struct device is passed in, the newly created |
|
* struct device will be a child of that device in sysfs. |
|
* The pointer to the struct device will be returned from the call. |
|
* Any further sysfs files that might be required can be created using this |
|
* pointer. |
|
* |
|
* Returns &struct device pointer on success, or ERR_PTR() on error. |
|
* |
|
* Note: the struct class passed to this function must have previously |
|
* been created with a call to class_create(). |
|
*/ |
|
struct device *device_create(struct class *class, struct device *parent, |
|
dev_t devt, void *drvdata, const char *fmt, ...) |
|
{ |
|
va_list vargs; |
|
struct device *dev; |
|
|
|
va_start(vargs, fmt); |
|
dev = device_create_groups_vargs(class, parent, devt, drvdata, NULL, |
|
fmt, vargs); |
|
va_end(vargs); |
|
return dev; |
|
} |
|
EXPORT_SYMBOL_GPL(device_create); |
|
|
|
/** |
|
* device_create_with_groups - creates a device and registers it with sysfs |
|
* @class: pointer to the struct class that this device should be registered to |
|
* @parent: pointer to the parent struct device of this new device, if any |
|
* @devt: the dev_t for the char device to be added |
|
* @drvdata: the data to be added to the device for callbacks |
|
* @groups: NULL-terminated list of attribute groups to be created |
|
* @fmt: string for the device's name |
|
* |
|
* This function can be used by char device classes. A struct device |
|
* will be created in sysfs, registered to the specified class. |
|
* Additional attributes specified in the groups parameter will also |
|
* be created automatically. |
|
* |
|
* A "dev" file will be created, showing the dev_t for the device, if |
|
* the dev_t is not 0,0. |
|
* If a pointer to a parent struct device is passed in, the newly created |
|
* struct device will be a child of that device in sysfs. |
|
* The pointer to the struct device will be returned from the call. |
|
* Any further sysfs files that might be required can be created using this |
|
* pointer. |
|
* |
|
* Returns &struct device pointer on success, or ERR_PTR() on error. |
|
* |
|
* Note: the struct class passed to this function must have previously |
|
* been created with a call to class_create(). |
|
*/ |
|
struct device *device_create_with_groups(struct class *class, |
|
struct device *parent, dev_t devt, |
|
void *drvdata, |
|
const struct attribute_group **groups, |
|
const char *fmt, ...) |
|
{ |
|
va_list vargs; |
|
struct device *dev; |
|
|
|
va_start(vargs, fmt); |
|
dev = device_create_groups_vargs(class, parent, devt, drvdata, groups, |
|
fmt, vargs); |
|
va_end(vargs); |
|
return dev; |
|
} |
|
EXPORT_SYMBOL_GPL(device_create_with_groups); |
|
|
|
/** |
|
* device_destroy - removes a device that was created with device_create() |
|
* @class: pointer to the struct class that this device was registered with |
|
* @devt: the dev_t of the device that was previously registered |
|
* |
|
* This call unregisters and cleans up a device that was created with a |
|
* call to device_create(). |
|
*/ |
|
void device_destroy(struct class *class, dev_t devt) |
|
{ |
|
struct device *dev; |
|
|
|
dev = class_find_device_by_devt(class, devt); |
|
if (dev) { |
|
put_device(dev); |
|
device_unregister(dev); |
|
} |
|
} |
|
EXPORT_SYMBOL_GPL(device_destroy); |
|
|
|
/** |
|
* device_rename - renames a device |
|
* @dev: the pointer to the struct device to be renamed |
|
* @new_name: the new name of the device |
|
* |
|
* It is the responsibility of the caller to provide mutual |
|
* exclusion between two different calls of device_rename |
|
* on the same device to ensure that new_name is valid and |
|
* won't conflict with other devices. |
|
* |
|
* Note: Don't call this function. Currently, the networking layer calls this |
|
* function, but that will change. The following text from Kay Sievers offers |
|
* some insight: |
|
* |
|
* Renaming devices is racy at many levels, symlinks and other stuff are not |
|
* replaced atomically, and you get a "move" uevent, but it's not easy to |
|
* connect the event to the old and new device. Device nodes are not renamed at |
|
* all, there isn't even support for that in the kernel now. |
|
* |
|
* In the meantime, during renaming, your target name might be taken by another |
|
* driver, creating conflicts. Or the old name is taken directly after you |
|
* renamed it -- then you get events for the same DEVPATH, before you even see |
|
* the "move" event. It's just a mess, and nothing new should ever rely on |
|
* kernel device renaming. Besides that, it's not even implemented now for |
|
* other things than (driver-core wise very simple) network devices. |
|
* |
|
* We are currently about to change network renaming in udev to completely |
|
* disallow renaming of devices in the same namespace as the kernel uses, |
|
* because we can't solve the problems properly, that arise with swapping names |
|
* of multiple interfaces without races. Means, renaming of eth[0-9]* will only |
|
* be allowed to some other name than eth[0-9]*, for the aforementioned |
|
* reasons. |
|
* |
|
* Make up a "real" name in the driver before you register anything, or add |
|
* some other attributes for userspace to find the device, or use udev to add |
|
* symlinks -- but never rename kernel devices later, it's a complete mess. We |
|
* don't even want to get into that and try to implement the missing pieces in |
|
* the core. We really have other pieces to fix in the driver core mess. :) |
|
*/ |
|
int device_rename(struct device *dev, const char *new_name) |
|
{ |
|
struct kobject *kobj = &dev->kobj; |
|
char *old_device_name = NULL; |
|
int error; |
|
|
|
dev = get_device(dev); |
|
if (!dev) |
|
return -EINVAL; |
|
|
|
dev_dbg(dev, "renaming to %s\n", new_name); |
|
|
|
old_device_name = kstrdup(dev_name(dev), GFP_KERNEL); |
|
if (!old_device_name) { |
|
error = -ENOMEM; |
|
goto out; |
|
} |
|
|
|
if (dev->class) { |
|
error = sysfs_rename_link_ns(&dev->class->p->subsys.kobj, |
|
kobj, old_device_name, |
|
new_name, kobject_namespace(kobj)); |
|
if (error) |
|
goto out; |
|
} |
|
|
|
error = kobject_rename(kobj, new_name); |
|
if (error) |
|
goto out; |
|
|
|
out: |
|
put_device(dev); |
|
|
|
kfree(old_device_name); |
|
|
|
return error; |
|
} |
|
EXPORT_SYMBOL_GPL(device_rename); |
|
|
|
static int device_move_class_links(struct device *dev, |
|
struct device *old_parent, |
|
struct device *new_parent) |
|
{ |
|
int error = 0; |
|
|
|
if (old_parent) |
|
sysfs_remove_link(&dev->kobj, "device"); |
|
if (new_parent) |
|
error = sysfs_create_link(&dev->kobj, &new_parent->kobj, |
|
"device"); |
|
return error; |
|
} |
|
|
|
/** |
|
* device_move - moves a device to a new parent |
|
* @dev: the pointer to the struct device to be moved |
|
* @new_parent: the new parent of the device (can be NULL) |
|
* @dpm_order: how to reorder the dpm_list |
|
*/ |
|
int device_move(struct device *dev, struct device *new_parent, |
|
enum dpm_order dpm_order) |
|
{ |
|
int error; |
|
struct device *old_parent; |
|
struct kobject *new_parent_kobj; |
|
|
|
dev = get_device(dev); |
|
if (!dev) |
|
return -EINVAL; |
|
|
|
device_pm_lock(); |
|
new_parent = get_device(new_parent); |
|
new_parent_kobj = get_device_parent(dev, new_parent); |
|
if (IS_ERR(new_parent_kobj)) { |
|
error = PTR_ERR(new_parent_kobj); |
|
put_device(new_parent); |
|
goto out; |
|
} |
|
|
|
pr_debug("device: '%s': %s: moving to '%s'\n", dev_name(dev), |
|
__func__, new_parent ? dev_name(new_parent) : "<NULL>"); |
|
error = kobject_move(&dev->kobj, new_parent_kobj); |
|
if (error) { |
|
cleanup_glue_dir(dev, new_parent_kobj); |
|
put_device(new_parent); |
|
goto out; |
|
} |
|
old_parent = dev->parent; |
|
dev->parent = new_parent; |
|
if (old_parent) |
|
klist_remove(&dev->p->knode_parent); |
|
if (new_parent) { |
|
klist_add_tail(&dev->p->knode_parent, |
|
&new_parent->p->klist_children); |
|
set_dev_node(dev, dev_to_node(new_parent)); |
|
} |
|
|
|
if (dev->class) { |
|
error = device_move_class_links(dev, old_parent, new_parent); |
|
if (error) { |
|
/* We ignore errors on cleanup since we're hosed anyway... */ |
|
device_move_class_links(dev, new_parent, old_parent); |
|
if (!kobject_move(&dev->kobj, &old_parent->kobj)) { |
|
if (new_parent) |
|
klist_remove(&dev->p->knode_parent); |
|
dev->parent = old_parent; |
|
if (old_parent) { |
|
klist_add_tail(&dev->p->knode_parent, |
|
&old_parent->p->klist_children); |
|
set_dev_node(dev, dev_to_node(old_parent)); |
|
} |
|
} |
|
cleanup_glue_dir(dev, new_parent_kobj); |
|
put_device(new_parent); |
|
goto out; |
|
} |
|
} |
|
switch (dpm_order) { |
|
case DPM_ORDER_NONE: |
|
break; |
|
case DPM_ORDER_DEV_AFTER_PARENT: |
|
device_pm_move_after(dev, new_parent); |
|
devices_kset_move_after(dev, new_parent); |
|
break; |
|
case DPM_ORDER_PARENT_BEFORE_DEV: |
|
device_pm_move_before(new_parent, dev); |
|
devices_kset_move_before(new_parent, dev); |
|
break; |
|
case DPM_ORDER_DEV_LAST: |
|
device_pm_move_last(dev); |
|
devices_kset_move_last(dev); |
|
break; |
|
} |
|
|
|
put_device(old_parent); |
|
out: |
|
device_pm_unlock(); |
|
put_device(dev); |
|
return error; |
|
} |
|
EXPORT_SYMBOL_GPL(device_move); |
|
|
|
static int device_attrs_change_owner(struct device *dev, kuid_t kuid, |
|
kgid_t kgid) |
|
{ |
|
struct kobject *kobj = &dev->kobj; |
|
struct class *class = dev->class; |
|
const struct device_type *type = dev->type; |
|
int error; |
|
|
|
if (class) { |
|
/* |
|
* Change the device groups of the device class for @dev to |
|
* @kuid/@kgid. |
|
*/ |
|
error = sysfs_groups_change_owner(kobj, class->dev_groups, kuid, |
|
kgid); |
|
if (error) |
|
return error; |
|
} |
|
|
|
if (type) { |
|
/* |
|
* Change the device groups of the device type for @dev to |
|
* @kuid/@kgid. |
|
*/ |
|
error = sysfs_groups_change_owner(kobj, type->groups, kuid, |
|
kgid); |
|
if (error) |
|
return error; |
|
} |
|
|
|
/* Change the device groups of @dev to @kuid/@kgid. */ |
|
error = sysfs_groups_change_owner(kobj, dev->groups, kuid, kgid); |
|
if (error) |
|
return error; |
|
|
|
if (device_supports_offline(dev) && !dev->offline_disabled) { |
|
/* Change online device attributes of @dev to @kuid/@kgid. */ |
|
error = sysfs_file_change_owner(kobj, dev_attr_online.attr.name, |
|
kuid, kgid); |
|
if (error) |
|
return error; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
/** |
|
* device_change_owner - change the owner of an existing device. |
|
* @dev: device. |
|
* @kuid: new owner's kuid |
|
* @kgid: new owner's kgid |
|
* |
|
* This changes the owner of @dev and its corresponding sysfs entries to |
|
* @kuid/@kgid. This function closely mirrors how @dev was added via driver |
|
* core. |
|
* |
|
* Returns 0 on success or error code on failure. |
|
*/ |
|
int device_change_owner(struct device *dev, kuid_t kuid, kgid_t kgid) |
|
{ |
|
int error; |
|
struct kobject *kobj = &dev->kobj; |
|
|
|
dev = get_device(dev); |
|
if (!dev) |
|
return -EINVAL; |
|
|
|
/* |
|
* Change the kobject and the default attributes and groups of the |
|
* ktype associated with it to @kuid/@kgid. |
|
*/ |
|
error = sysfs_change_owner(kobj, kuid, kgid); |
|
if (error) |
|
goto out; |
|
|
|
/* |
|
* Change the uevent file for @dev to the new owner. The uevent file |
|
* was created in a separate step when @dev got added and we mirror |
|
* that step here. |
|
*/ |
|
error = sysfs_file_change_owner(kobj, dev_attr_uevent.attr.name, kuid, |
|
kgid); |
|
if (error) |
|
goto out; |
|
|
|
/* |
|
* Change the device groups, the device groups associated with the |
|
* device class, and the groups associated with the device type of @dev |
|
* to @kuid/@kgid. |
|
*/ |
|
error = device_attrs_change_owner(dev, kuid, kgid); |
|
if (error) |
|
goto out; |
|
|
|
error = dpm_sysfs_change_owner(dev, kuid, kgid); |
|
if (error) |
|
goto out; |
|
|
|
#ifdef CONFIG_BLOCK |
|
if (sysfs_deprecated && dev->class == &block_class) |
|
goto out; |
|
#endif |
|
|
|
/* |
|
* Change the owner of the symlink located in the class directory of |
|
* the device class associated with @dev which points to the actual |
|
* directory entry for @dev to @kuid/@kgid. This ensures that the |
|
* symlink shows the same permissions as its target. |
|
*/ |
|
error = sysfs_link_change_owner(&dev->class->p->subsys.kobj, &dev->kobj, |
|
dev_name(dev), kuid, kgid); |
|
if (error) |
|
goto out; |
|
|
|
out: |
|
put_device(dev); |
|
return error; |
|
} |
|
EXPORT_SYMBOL_GPL(device_change_owner); |
|
|
|
/** |
|
* device_shutdown - call ->shutdown() on each device to shutdown. |
|
*/ |
|
void device_shutdown(void) |
|
{ |
|
struct device *dev, *parent; |
|
|
|
wait_for_device_probe(); |
|
device_block_probing(); |
|
|
|
cpufreq_suspend(); |
|
|
|
spin_lock(&devices_kset->list_lock); |
|
/* |
|
* Walk the devices list backward, shutting down each in turn. |
|
* Beware that device unplug events may also start pulling |
|
* devices offline, even as the system is shutting down. |
|
*/ |
|
while (!list_empty(&devices_kset->list)) { |
|
dev = list_entry(devices_kset->list.prev, struct device, |
|
kobj.entry); |
|
|
|
/* |
|
* hold reference count of device's parent to |
|
* prevent it from being freed because parent's |
|
* lock is to be held |
|
*/ |
|
parent = get_device(dev->parent); |
|
get_device(dev); |
|
/* |
|
* Make sure the device is off the kset list, in the |
|
* event that dev->*->shutdown() doesn't remove it. |
|
*/ |
|
list_del_init(&dev->kobj.entry); |
|
spin_unlock(&devices_kset->list_lock); |
|
|
|
/* hold lock to avoid race with probe/release */ |
|
if (parent) |
|
device_lock(parent); |
|
device_lock(dev); |
|
|
|
/* Don't allow any more runtime suspends */ |
|
pm_runtime_get_noresume(dev); |
|
pm_runtime_barrier(dev); |
|
|
|
if (dev->class && dev->class->shutdown_pre) { |
|
if (initcall_debug) |
|
dev_info(dev, "shutdown_pre\n"); |
|
dev->class->shutdown_pre(dev); |
|
} |
|
if (dev->bus && dev->bus->shutdown) { |
|
if (initcall_debug) |
|
dev_info(dev, "shutdown\n"); |
|
dev->bus->shutdown(dev); |
|
} else if (dev->driver && dev->driver->shutdown) { |
|
if (initcall_debug) |
|
dev_info(dev, "shutdown\n"); |
|
dev->driver->shutdown(dev); |
|
} |
|
|
|
device_unlock(dev); |
|
if (parent) |
|
device_unlock(parent); |
|
|
|
put_device(dev); |
|
put_device(parent); |
|
|
|
spin_lock(&devices_kset->list_lock); |
|
} |
|
spin_unlock(&devices_kset->list_lock); |
|
} |
|
|
|
/* |
|
* Device logging functions |
|
*/ |
|
|
|
#ifdef CONFIG_PRINTK |
|
static void |
|
set_dev_info(const struct device *dev, struct dev_printk_info *dev_info) |
|
{ |
|
const char *subsys; |
|
|
|
memset(dev_info, 0, sizeof(*dev_info)); |
|
|
|
if (dev->class) |
|
subsys = dev->class->name; |
|
else if (dev->bus) |
|
subsys = dev->bus->name; |
|
else |
|
return; |
|
|
|
strscpy(dev_info->subsystem, subsys, sizeof(dev_info->subsystem)); |
|
|
|
/* |
|
* Add device identifier DEVICE=: |
|
* b12:8 block dev_t |
|
* c127:3 char dev_t |
|
* n8 netdev ifindex |
|
* +sound:card0 subsystem:devname |
|
*/ |
|
if (MAJOR(dev->devt)) { |
|
char c; |
|
|
|
if (strcmp(subsys, "block") == 0) |
|
c = 'b'; |
|
else |
|
c = 'c'; |
|
|
|
snprintf(dev_info->device, sizeof(dev_info->device), |
|
"%c%u:%u", c, MAJOR(dev->devt), MINOR(dev->devt)); |
|
} else if (strcmp(subsys, "net") == 0) { |
|
struct net_device *net = to_net_dev(dev); |
|
|
|
snprintf(dev_info->device, sizeof(dev_info->device), |
|
"n%u", net->ifindex); |
|
} else { |
|
snprintf(dev_info->device, sizeof(dev_info->device), |
|
"+%s:%s", subsys, dev_name(dev)); |
|
} |
|
} |
|
|
|
int dev_vprintk_emit(int level, const struct device *dev, |
|
const char *fmt, va_list args) |
|
{ |
|
struct dev_printk_info dev_info; |
|
|
|
set_dev_info(dev, &dev_info); |
|
|
|
return vprintk_emit(0, level, &dev_info, fmt, args); |
|
} |
|
EXPORT_SYMBOL(dev_vprintk_emit); |
|
|
|
int dev_printk_emit(int level, const struct device *dev, const char *fmt, ...) |
|
{ |
|
va_list args; |
|
int r; |
|
|
|
va_start(args, fmt); |
|
|
|
r = dev_vprintk_emit(level, dev, fmt, args); |
|
|
|
va_end(args); |
|
|
|
return r; |
|
} |
|
EXPORT_SYMBOL(dev_printk_emit); |
|
|
|
static void __dev_printk(const char *level, const struct device *dev, |
|
struct va_format *vaf) |
|
{ |
|
if (dev) |
|
dev_printk_emit(level[1] - '0', dev, "%s %s: %pV", |
|
dev_driver_string(dev), dev_name(dev), vaf); |
|
else |
|
printk("%s(NULL device *): %pV", level, vaf); |
|
} |
|
|
|
void dev_printk(const char *level, const struct device *dev, |
|
const char *fmt, ...) |
|
{ |
|
struct va_format vaf; |
|
va_list args; |
|
|
|
va_start(args, fmt); |
|
|
|
vaf.fmt = fmt; |
|
vaf.va = &args; |
|
|
|
__dev_printk(level, dev, &vaf); |
|
|
|
va_end(args); |
|
} |
|
EXPORT_SYMBOL(dev_printk); |
|
|
|
#define define_dev_printk_level(func, kern_level) \ |
|
void func(const struct device *dev, const char *fmt, ...) \ |
|
{ \ |
|
struct va_format vaf; \ |
|
va_list args; \ |
|
\ |
|
va_start(args, fmt); \ |
|
\ |
|
vaf.fmt = fmt; \ |
|
vaf.va = &args; \ |
|
\ |
|
__dev_printk(kern_level, dev, &vaf); \ |
|
\ |
|
va_end(args); \ |
|
} \ |
|
EXPORT_SYMBOL(func); |
|
|
|
define_dev_printk_level(_dev_emerg, KERN_EMERG); |
|
define_dev_printk_level(_dev_alert, KERN_ALERT); |
|
define_dev_printk_level(_dev_crit, KERN_CRIT); |
|
define_dev_printk_level(_dev_err, KERN_ERR); |
|
define_dev_printk_level(_dev_warn, KERN_WARNING); |
|
define_dev_printk_level(_dev_notice, KERN_NOTICE); |
|
define_dev_printk_level(_dev_info, KERN_INFO); |
|
|
|
#endif |
|
|
|
/** |
|
* dev_err_probe - probe error check and log helper |
|
* @dev: the pointer to the struct device |
|
* @err: error value to test |
|
* @fmt: printf-style format string |
|
* @...: arguments as specified in the format string |
|
* |
|
* This helper implements common pattern present in probe functions for error |
|
* checking: print debug or error message depending if the error value is |
|
* -EPROBE_DEFER and propagate error upwards. |
|
* In case of -EPROBE_DEFER it sets also defer probe reason, which can be |
|
* checked later by reading devices_deferred debugfs attribute. |
|
* It replaces code sequence:: |
|
* |
|
* if (err != -EPROBE_DEFER) |
|
* dev_err(dev, ...); |
|
* else |
|
* dev_dbg(dev, ...); |
|
* return err; |
|
* |
|
* with:: |
|
* |
|
* return dev_err_probe(dev, err, ...); |
|
* |
|
* Returns @err. |
|
* |
|
*/ |
|
int dev_err_probe(const struct device *dev, int err, const char *fmt, ...) |
|
{ |
|
struct va_format vaf; |
|
va_list args; |
|
|
|
va_start(args, fmt); |
|
vaf.fmt = fmt; |
|
vaf.va = &args; |
|
|
|
if (err != -EPROBE_DEFER) { |
|
dev_err(dev, "error %pe: %pV", ERR_PTR(err), &vaf); |
|
} else { |
|
device_set_deferred_probe_reason(dev, &vaf); |
|
dev_dbg(dev, "error %pe: %pV", ERR_PTR(err), &vaf); |
|
} |
|
|
|
va_end(args); |
|
|
|
return err; |
|
} |
|
EXPORT_SYMBOL_GPL(dev_err_probe); |
|
|
|
static inline bool fwnode_is_primary(struct fwnode_handle *fwnode) |
|
{ |
|
return fwnode && !IS_ERR(fwnode->secondary); |
|
} |
|
|
|
/** |
|
* set_primary_fwnode - Change the primary firmware node of a given device. |
|
* @dev: Device to handle. |
|
* @fwnode: New primary firmware node of the device. |
|
* |
|
* Set the device's firmware node pointer to @fwnode, but if a secondary |
|
* firmware node of the device is present, preserve it. |
|
* |
|
* Valid fwnode cases are: |
|
* - primary --> secondary --> -ENODEV |
|
* - primary --> NULL |
|
* - secondary --> -ENODEV |
|
* - NULL |
|
*/ |
|
void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode) |
|
{ |
|
struct device *parent = dev->parent; |
|
struct fwnode_handle *fn = dev->fwnode; |
|
|
|
if (fwnode) { |
|
if (fwnode_is_primary(fn)) |
|
fn = fn->secondary; |
|
|
|
if (fn) { |
|
WARN_ON(fwnode->secondary); |
|
fwnode->secondary = fn; |
|
} |
|
dev->fwnode = fwnode; |
|
} else { |
|
if (fwnode_is_primary(fn)) { |
|
dev->fwnode = fn->secondary; |
|
/* Set fn->secondary = NULL, so fn remains the primary fwnode */ |
|
if (!(parent && fn == parent->fwnode)) |
|
fn->secondary = NULL; |
|
} else { |
|
dev->fwnode = NULL; |
|
} |
|
} |
|
} |
|
EXPORT_SYMBOL_GPL(set_primary_fwnode); |
|
|
|
/** |
|
* set_secondary_fwnode - Change the secondary firmware node of a given device. |
|
* @dev: Device to handle. |
|
* @fwnode: New secondary firmware node of the device. |
|
* |
|
* If a primary firmware node of the device is present, set its secondary |
|
* pointer to @fwnode. Otherwise, set the device's firmware node pointer to |
|
* @fwnode. |
|
*/ |
|
void set_secondary_fwnode(struct device *dev, struct fwnode_handle *fwnode) |
|
{ |
|
if (fwnode) |
|
fwnode->secondary = ERR_PTR(-ENODEV); |
|
|
|
if (fwnode_is_primary(dev->fwnode)) |
|
dev->fwnode->secondary = fwnode; |
|
else |
|
dev->fwnode = fwnode; |
|
} |
|
EXPORT_SYMBOL_GPL(set_secondary_fwnode); |
|
|
|
/** |
|
* device_set_of_node_from_dev - reuse device-tree node of another device |
|
* @dev: device whose device-tree node is being set |
|
* @dev2: device whose device-tree node is being reused |
|
* |
|
* Takes another reference to the new device-tree node after first dropping |
|
* any reference held to the old node. |
|
*/ |
|
void device_set_of_node_from_dev(struct device *dev, const struct device *dev2) |
|
{ |
|
of_node_put(dev->of_node); |
|
dev->of_node = of_node_get(dev2->of_node); |
|
dev->of_node_reused = true; |
|
} |
|
EXPORT_SYMBOL_GPL(device_set_of_node_from_dev); |
|
|
|
int device_match_name(struct device *dev, const void *name) |
|
{ |
|
return sysfs_streq(dev_name(dev), name); |
|
} |
|
EXPORT_SYMBOL_GPL(device_match_name); |
|
|
|
int device_match_of_node(struct device *dev, const void *np) |
|
{ |
|
return dev->of_node == np; |
|
} |
|
EXPORT_SYMBOL_GPL(device_match_of_node); |
|
|
|
int device_match_fwnode(struct device *dev, const void *fwnode) |
|
{ |
|
return dev_fwnode(dev) == fwnode; |
|
} |
|
EXPORT_SYMBOL_GPL(device_match_fwnode); |
|
|
|
int device_match_devt(struct device *dev, const void *pdevt) |
|
{ |
|
return dev->devt == *(dev_t *)pdevt; |
|
} |
|
EXPORT_SYMBOL_GPL(device_match_devt); |
|
|
|
int device_match_acpi_dev(struct device *dev, const void *adev) |
|
{ |
|
return ACPI_COMPANION(dev) == adev; |
|
} |
|
EXPORT_SYMBOL(device_match_acpi_dev); |
|
|
|
int device_match_any(struct device *dev, const void *unused) |
|
{ |
|
return 1; |
|
} |
|
EXPORT_SYMBOL_GPL(device_match_any);
|
|
|