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428 lines
10 KiB
428 lines
10 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* Copyright IBM Corp. 2020 |
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* |
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* Author(s): |
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* Pierre Morel <[email protected]> |
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* |
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*/ |
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#define KMSG_COMPONENT "zpci" |
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#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt |
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#include <linux/kernel.h> |
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#include <linux/slab.h> |
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#include <linux/err.h> |
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#include <linux/export.h> |
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#include <linux/delay.h> |
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#include <linux/seq_file.h> |
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#include <linux/jump_label.h> |
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#include <linux/pci.h> |
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#include <linux/printk.h> |
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#include <asm/pci_clp.h> |
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#include <asm/pci_dma.h> |
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#include "pci_bus.h" |
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#include "pci_iov.h" |
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static LIST_HEAD(zbus_list); |
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static DEFINE_MUTEX(zbus_list_lock); |
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static int zpci_nb_devices; |
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/* zpci_bus_prepare_device - Prepare a zPCI function for scanning |
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* @zdev: the zPCI function to be prepared |
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* |
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* The PCI resources for the function are set up and added to its zbus and the |
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* function is enabled. The function must be added to a zbus which must have |
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* a PCI bus created. If an error occurs the zPCI function is not enabled. |
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* |
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* Return: 0 on success, an error code otherwise |
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*/ |
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static int zpci_bus_prepare_device(struct zpci_dev *zdev) |
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{ |
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struct resource_entry *window, *n; |
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struct resource *res; |
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int rc; |
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if (!zdev_enabled(zdev)) { |
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rc = zpci_enable_device(zdev); |
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if (rc) |
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return rc; |
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rc = zpci_dma_init_device(zdev); |
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if (rc) { |
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zpci_disable_device(zdev); |
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return rc; |
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} |
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} |
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if (!zdev->has_resources) { |
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zpci_setup_bus_resources(zdev, &zdev->zbus->resources); |
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resource_list_for_each_entry_safe(window, n, &zdev->zbus->resources) { |
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res = window->res; |
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pci_bus_add_resource(zdev->zbus->bus, res, 0); |
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} |
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} |
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return 0; |
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} |
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/* zpci_bus_scan_device - Scan a single device adding it to the PCI core |
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* @zdev: the zdev to be scanned |
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* |
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* Scans the PCI function making it available to the common PCI code. |
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* |
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* Return: 0 on success, an error value otherwise |
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*/ |
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int zpci_bus_scan_device(struct zpci_dev *zdev) |
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{ |
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struct pci_dev *pdev; |
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int rc; |
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rc = zpci_bus_prepare_device(zdev); |
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if (rc) |
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return rc; |
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pdev = pci_scan_single_device(zdev->zbus->bus, zdev->devfn); |
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if (!pdev) |
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return -ENODEV; |
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pci_bus_add_device(pdev); |
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pci_lock_rescan_remove(); |
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pci_bus_add_devices(zdev->zbus->bus); |
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pci_unlock_rescan_remove(); |
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return 0; |
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} |
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/* zpci_bus_remove_device - Removes the given zdev from the PCI core |
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* @zdev: the zdev to be removed from the PCI core |
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* @set_error: if true the device's error state is set to permanent failure |
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* |
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* Sets a zPCI device to a configured but offline state; the zPCI |
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* device is still accessible through its hotplug slot and the zPCI |
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* API but is removed from the common code PCI bus, making it |
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* no longer available to drivers. |
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*/ |
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void zpci_bus_remove_device(struct zpci_dev *zdev, bool set_error) |
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{ |
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struct zpci_bus *zbus = zdev->zbus; |
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struct pci_dev *pdev; |
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if (!zdev->zbus->bus) |
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return; |
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pdev = pci_get_slot(zbus->bus, zdev->devfn); |
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if (pdev) { |
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if (set_error) |
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pdev->error_state = pci_channel_io_perm_failure; |
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if (pdev->is_virtfn) { |
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zpci_iov_remove_virtfn(pdev, zdev->vfn); |
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/* balance pci_get_slot */ |
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pci_dev_put(pdev); |
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return; |
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} |
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pci_stop_and_remove_bus_device_locked(pdev); |
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/* balance pci_get_slot */ |
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pci_dev_put(pdev); |
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} |
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} |
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/* zpci_bus_scan_bus - Scan all configured zPCI functions on the bus |
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* @zbus: the zbus to be scanned |
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* |
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* Enables and scans all PCI functions on the bus making them available to the |
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* common PCI code. If there is no function 0 on the zbus nothing is scanned. If |
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* a function does not have a slot yet because it was added to the zbus before |
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* function 0 the slot is created. If a PCI function fails to be initialized |
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* an error will be returned but attempts will still be made for all other |
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* functions on the bus. |
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* |
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* Return: 0 on success, an error value otherwise |
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*/ |
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int zpci_bus_scan_bus(struct zpci_bus *zbus) |
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{ |
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struct zpci_dev *zdev; |
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int devfn, rc, ret = 0; |
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if (!zbus->function[0]) |
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return 0; |
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for (devfn = 0; devfn < ZPCI_FUNCTIONS_PER_BUS; devfn++) { |
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zdev = zbus->function[devfn]; |
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if (zdev && zdev->state == ZPCI_FN_STATE_CONFIGURED) { |
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rc = zpci_bus_prepare_device(zdev); |
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if (rc) |
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ret = -EIO; |
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} |
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} |
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pci_lock_rescan_remove(); |
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pci_scan_child_bus(zbus->bus); |
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pci_bus_add_devices(zbus->bus); |
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pci_unlock_rescan_remove(); |
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return ret; |
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} |
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/* zpci_bus_scan_busses - Scan all registered busses |
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* |
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* Scan all available zbusses |
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* |
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*/ |
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void zpci_bus_scan_busses(void) |
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{ |
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struct zpci_bus *zbus = NULL; |
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mutex_lock(&zbus_list_lock); |
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list_for_each_entry(zbus, &zbus_list, bus_next) { |
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zpci_bus_scan_bus(zbus); |
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cond_resched(); |
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} |
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mutex_unlock(&zbus_list_lock); |
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} |
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/* zpci_bus_create_pci_bus - Create the PCI bus associated with this zbus |
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* @zbus: the zbus holding the zdevices |
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* @f0: function 0 of the bus |
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* @ops: the pci operations |
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* |
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* Function zero is taken as a parameter as this is used to determine the |
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* domain, multifunction property and maximum bus speed of the entire bus. |
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* |
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* Return: 0 on success, an error code otherwise |
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*/ |
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static int zpci_bus_create_pci_bus(struct zpci_bus *zbus, struct zpci_dev *f0, struct pci_ops *ops) |
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{ |
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struct pci_bus *bus; |
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int domain; |
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domain = zpci_alloc_domain((u16)f0->uid); |
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if (domain < 0) |
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return domain; |
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zbus->domain_nr = domain; |
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zbus->multifunction = f0->rid_available; |
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zbus->max_bus_speed = f0->max_bus_speed; |
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/* |
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* Note that the zbus->resources are taken over and zbus->resources |
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* is empty after a successful call |
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*/ |
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bus = pci_create_root_bus(NULL, ZPCI_BUS_NR, ops, zbus, &zbus->resources); |
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if (!bus) { |
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zpci_free_domain(zbus->domain_nr); |
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return -EFAULT; |
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} |
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zbus->bus = bus; |
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pci_bus_add_devices(bus); |
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return 0; |
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} |
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static void zpci_bus_release(struct kref *kref) |
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{ |
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struct zpci_bus *zbus = container_of(kref, struct zpci_bus, kref); |
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if (zbus->bus) { |
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pci_lock_rescan_remove(); |
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pci_stop_root_bus(zbus->bus); |
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zpci_free_domain(zbus->domain_nr); |
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pci_free_resource_list(&zbus->resources); |
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pci_remove_root_bus(zbus->bus); |
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pci_unlock_rescan_remove(); |
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} |
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mutex_lock(&zbus_list_lock); |
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list_del(&zbus->bus_next); |
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mutex_unlock(&zbus_list_lock); |
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kfree(zbus); |
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} |
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static void zpci_bus_put(struct zpci_bus *zbus) |
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{ |
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kref_put(&zbus->kref, zpci_bus_release); |
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} |
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static struct zpci_bus *zpci_bus_get(int pchid) |
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{ |
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struct zpci_bus *zbus; |
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mutex_lock(&zbus_list_lock); |
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list_for_each_entry(zbus, &zbus_list, bus_next) { |
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if (pchid == zbus->pchid) { |
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kref_get(&zbus->kref); |
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goto out_unlock; |
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} |
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} |
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zbus = NULL; |
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out_unlock: |
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mutex_unlock(&zbus_list_lock); |
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return zbus; |
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} |
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static struct zpci_bus *zpci_bus_alloc(int pchid) |
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{ |
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struct zpci_bus *zbus; |
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zbus = kzalloc(sizeof(*zbus), GFP_KERNEL); |
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if (!zbus) |
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return NULL; |
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zbus->pchid = pchid; |
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INIT_LIST_HEAD(&zbus->bus_next); |
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mutex_lock(&zbus_list_lock); |
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list_add_tail(&zbus->bus_next, &zbus_list); |
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mutex_unlock(&zbus_list_lock); |
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kref_init(&zbus->kref); |
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INIT_LIST_HEAD(&zbus->resources); |
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zbus->bus_resource.start = 0; |
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zbus->bus_resource.end = ZPCI_BUS_NR; |
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zbus->bus_resource.flags = IORESOURCE_BUS; |
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pci_add_resource(&zbus->resources, &zbus->bus_resource); |
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return zbus; |
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} |
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void pcibios_bus_add_device(struct pci_dev *pdev) |
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{ |
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struct zpci_dev *zdev = to_zpci(pdev); |
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/* |
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* With pdev->no_vf_scan the common PCI probing code does not |
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* perform PF/VF linking. |
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*/ |
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if (zdev->vfn) { |
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zpci_iov_setup_virtfn(zdev->zbus, pdev, zdev->vfn); |
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pdev->no_command_memory = 1; |
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} |
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} |
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/* zpci_bus_create_hotplug_slots - Add hotplug slot(s) for device added to bus |
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* @zdev: the zPCI device that was newly added |
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* |
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* Add the hotplug slot(s) for the newly added PCI function. Normally this is |
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* simply the slot for the function itself. If however we are adding the |
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* function 0 on a zbus, it might be that we already registered functions on |
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* that zbus but could not create their hotplug slots yet so add those now too. |
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* |
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* Return: 0 on success, an error code otherwise |
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*/ |
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static int zpci_bus_create_hotplug_slots(struct zpci_dev *zdev) |
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{ |
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struct zpci_bus *zbus = zdev->zbus; |
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int devfn, rc = 0; |
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rc = zpci_init_slot(zdev); |
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if (rc) |
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return rc; |
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zdev->has_hp_slot = 1; |
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if (zdev->devfn == 0 && zbus->multifunction) { |
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/* Now that function 0 is there we can finally create the |
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* hotplug slots for those functions with devfn != 0 that have |
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* been parked in zbus->function[] waiting for us to be able to |
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* create the PCI bus. |
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*/ |
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for (devfn = 1; devfn < ZPCI_FUNCTIONS_PER_BUS; devfn++) { |
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zdev = zbus->function[devfn]; |
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if (zdev && !zdev->has_hp_slot) { |
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rc = zpci_init_slot(zdev); |
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if (rc) |
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return rc; |
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zdev->has_hp_slot = 1; |
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} |
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} |
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} |
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return rc; |
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} |
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static int zpci_bus_add_device(struct zpci_bus *zbus, struct zpci_dev *zdev) |
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{ |
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int rc = -EINVAL; |
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if (zbus->function[zdev->devfn]) { |
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pr_err("devfn %04x is already assigned\n", zdev->devfn); |
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return rc; |
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} |
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zdev->zbus = zbus; |
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zbus->function[zdev->devfn] = zdev; |
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zpci_nb_devices++; |
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if (zbus->bus) { |
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if (zbus->multifunction && !zdev->rid_available) { |
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WARN_ONCE(1, "rid_available not set for multifunction\n"); |
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goto error; |
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} |
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zpci_bus_create_hotplug_slots(zdev); |
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} else { |
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/* Hotplug slot will be created once function 0 appears */ |
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zbus->multifunction = 1; |
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} |
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return 0; |
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error: |
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zbus->function[zdev->devfn] = NULL; |
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zdev->zbus = NULL; |
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zpci_nb_devices--; |
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return rc; |
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} |
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int zpci_bus_device_register(struct zpci_dev *zdev, struct pci_ops *ops) |
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{ |
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struct zpci_bus *zbus = NULL; |
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int rc = -EBADF; |
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if (zpci_nb_devices == ZPCI_NR_DEVICES) { |
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pr_warn("Adding PCI function %08x failed because the configured limit of %d is reached\n", |
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zdev->fid, ZPCI_NR_DEVICES); |
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return -ENOSPC; |
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} |
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if (zdev->devfn >= ZPCI_FUNCTIONS_PER_BUS) |
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return -EINVAL; |
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if (!s390_pci_no_rid && zdev->rid_available) |
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zbus = zpci_bus_get(zdev->pchid); |
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if (!zbus) { |
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zbus = zpci_bus_alloc(zdev->pchid); |
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if (!zbus) |
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return -ENOMEM; |
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} |
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if (zdev->devfn == 0) { |
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rc = zpci_bus_create_pci_bus(zbus, zdev, ops); |
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if (rc) |
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goto error; |
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} |
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rc = zpci_bus_add_device(zbus, zdev); |
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if (rc) |
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goto error; |
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return 0; |
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error: |
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pr_err("Adding PCI function %08x failed\n", zdev->fid); |
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zpci_bus_put(zbus); |
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return rc; |
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} |
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void zpci_bus_device_unregister(struct zpci_dev *zdev) |
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{ |
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struct zpci_bus *zbus = zdev->zbus; |
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zpci_nb_devices--; |
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zbus->function[zdev->devfn] = NULL; |
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zpci_bus_put(zbus); |
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}
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