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1567 lines
42 KiB
1567 lines
42 KiB
/* |
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* vgaarb.c: Implements the VGA arbitration. For details refer to |
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* Documentation/gpu/vgaarbiter.rst |
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* |
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* |
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* (C) Copyright 2005 Benjamin Herrenschmidt <[email protected]> |
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* (C) Copyright 2007 Paulo R. Zanoni <[email protected]> |
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* (C) Copyright 2007, 2009 Tiago Vignatti <[email protected]> |
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* |
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* Permission is hereby granted, free of charge, to any person obtaining a |
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* copy of this software and associated documentation files (the "Software"), |
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* to deal in the Software without restriction, including without limitation |
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* the rights to use, copy, modify, merge, publish, distribute, sublicense, |
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* and/or sell copies of the Software, and to permit persons to whom the |
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* Software is furnished to do so, subject to the following conditions: |
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* |
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* The above copyright notice and this permission notice (including the next |
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* paragraph) shall be included in all copies or substantial portions of the |
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* Software. |
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* |
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
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* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING |
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* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER |
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* DEALINGS |
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* IN THE SOFTWARE. |
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* |
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*/ |
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|
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#define pr_fmt(fmt) "vgaarb: " fmt |
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|
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#define vgaarb_dbg(dev, fmt, arg...) dev_dbg(dev, "vgaarb: " fmt, ##arg) |
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#define vgaarb_info(dev, fmt, arg...) dev_info(dev, "vgaarb: " fmt, ##arg) |
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#define vgaarb_err(dev, fmt, arg...) dev_err(dev, "vgaarb: " fmt, ##arg) |
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|
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#include <linux/module.h> |
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#include <linux/kernel.h> |
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#include <linux/pci.h> |
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#include <linux/errno.h> |
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#include <linux/init.h> |
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#include <linux/list.h> |
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#include <linux/sched/signal.h> |
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#include <linux/wait.h> |
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#include <linux/spinlock.h> |
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#include <linux/poll.h> |
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#include <linux/miscdevice.h> |
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#include <linux/slab.h> |
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#include <linux/screen_info.h> |
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#include <linux/vt.h> |
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#include <linux/console.h> |
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#include <linux/acpi.h> |
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|
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#include <linux/uaccess.h> |
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|
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#include <linux/vgaarb.h> |
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|
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static void vga_arbiter_notify_clients(void); |
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/* |
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* We keep a list of all vga devices in the system to speed |
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* up the various operations of the arbiter |
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*/ |
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struct vga_device { |
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struct list_head list; |
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struct pci_dev *pdev; |
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unsigned int decodes; /* what does it decodes */ |
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unsigned int owns; /* what does it owns */ |
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unsigned int locks; /* what does it locks */ |
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unsigned int io_lock_cnt; /* legacy IO lock count */ |
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unsigned int mem_lock_cnt; /* legacy MEM lock count */ |
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unsigned int io_norm_cnt; /* normal IO count */ |
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unsigned int mem_norm_cnt; /* normal MEM count */ |
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bool bridge_has_one_vga; |
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unsigned int (*set_decode)(struct pci_dev *pdev, bool decode); |
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}; |
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|
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static LIST_HEAD(vga_list); |
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static int vga_count, vga_decode_count; |
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static bool vga_arbiter_used; |
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static DEFINE_SPINLOCK(vga_lock); |
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static DECLARE_WAIT_QUEUE_HEAD(vga_wait_queue); |
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|
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|
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static const char *vga_iostate_to_str(unsigned int iostate) |
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{ |
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/* Ignore VGA_RSRC_IO and VGA_RSRC_MEM */ |
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iostate &= VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM; |
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switch (iostate) { |
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case VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM: |
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return "io+mem"; |
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case VGA_RSRC_LEGACY_IO: |
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return "io"; |
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case VGA_RSRC_LEGACY_MEM: |
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return "mem"; |
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} |
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return "none"; |
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} |
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|
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static int vga_str_to_iostate(char *buf, int str_size, int *io_state) |
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{ |
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/* we could in theory hand out locks on IO and mem |
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* separately to userspace but it can cause deadlocks */ |
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if (strncmp(buf, "none", 4) == 0) { |
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*io_state = VGA_RSRC_NONE; |
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return 1; |
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} |
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|
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/* XXX We're not chekcing the str_size! */ |
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if (strncmp(buf, "io+mem", 6) == 0) |
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goto both; |
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else if (strncmp(buf, "io", 2) == 0) |
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goto both; |
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else if (strncmp(buf, "mem", 3) == 0) |
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goto both; |
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return 0; |
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both: |
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*io_state = VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM; |
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return 1; |
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} |
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|
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/* this is only used a cookie - it should not be dereferenced */ |
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static struct pci_dev *vga_default; |
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|
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static void vga_arb_device_card_gone(struct pci_dev *pdev); |
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|
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/* Find somebody in our list */ |
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static struct vga_device *vgadev_find(struct pci_dev *pdev) |
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{ |
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struct vga_device *vgadev; |
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|
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list_for_each_entry(vgadev, &vga_list, list) |
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if (pdev == vgadev->pdev) |
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return vgadev; |
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return NULL; |
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} |
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|
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/** |
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* vga_default_device - return the default VGA device, for vgacon |
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* |
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* This can be defined by the platform. The default implementation |
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* is rather dumb and will probably only work properly on single |
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* vga card setups and/or x86 platforms. |
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* |
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* If your VGA default device is not PCI, you'll have to return |
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* NULL here. In this case, I assume it will not conflict with |
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* any PCI card. If this is not true, I'll have to define two archs |
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* hooks for enabling/disabling the VGA default device if that is |
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* possible. This may be a problem with real _ISA_ VGA cards, in |
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* addition to a PCI one. I don't know at this point how to deal |
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* with that card. Can theirs IOs be disabled at all ? If not, then |
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* I suppose it's a matter of having the proper arch hook telling |
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* us about it, so we basically never allow anybody to succeed a |
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* vga_get()... |
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*/ |
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struct pci_dev *vga_default_device(void) |
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{ |
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return vga_default; |
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} |
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EXPORT_SYMBOL_GPL(vga_default_device); |
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|
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void vga_set_default_device(struct pci_dev *pdev) |
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{ |
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if (vga_default == pdev) |
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return; |
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|
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pci_dev_put(vga_default); |
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vga_default = pci_dev_get(pdev); |
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} |
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|
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/** |
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* vga_remove_vgacon - deactivete vga console |
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* |
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* Unbind and unregister vgacon in case pdev is the default vga |
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* device. Can be called by gpu drivers on initialization to make |
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* sure vga register access done by vgacon will not disturb the |
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* device. |
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* |
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* @pdev: pci device. |
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*/ |
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#if !defined(CONFIG_VGA_CONSOLE) |
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int vga_remove_vgacon(struct pci_dev *pdev) |
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{ |
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return 0; |
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} |
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#elif !defined(CONFIG_DUMMY_CONSOLE) |
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int vga_remove_vgacon(struct pci_dev *pdev) |
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{ |
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return -ENODEV; |
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} |
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#else |
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int vga_remove_vgacon(struct pci_dev *pdev) |
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{ |
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int ret = 0; |
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|
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if (pdev != vga_default) |
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return 0; |
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vgaarb_info(&pdev->dev, "deactivate vga console\n"); |
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|
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console_lock(); |
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if (con_is_bound(&vga_con)) |
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ret = do_take_over_console(&dummy_con, 0, |
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MAX_NR_CONSOLES - 1, 1); |
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if (ret == 0) { |
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ret = do_unregister_con_driver(&vga_con); |
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|
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/* Ignore "already unregistered". */ |
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if (ret == -ENODEV) |
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ret = 0; |
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} |
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console_unlock(); |
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|
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return ret; |
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} |
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#endif |
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EXPORT_SYMBOL(vga_remove_vgacon); |
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|
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/* If we don't ever use VGA arb we should avoid |
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turning off anything anywhere due to old X servers getting |
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confused about the boot device not being VGA */ |
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static void vga_check_first_use(void) |
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{ |
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/* we should inform all GPUs in the system that |
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* VGA arb has occurred and to try and disable resources |
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* if they can */ |
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if (!vga_arbiter_used) { |
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vga_arbiter_used = true; |
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vga_arbiter_notify_clients(); |
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} |
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} |
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|
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static struct vga_device *__vga_tryget(struct vga_device *vgadev, |
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unsigned int rsrc) |
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{ |
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struct device *dev = &vgadev->pdev->dev; |
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unsigned int wants, legacy_wants, match; |
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struct vga_device *conflict; |
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unsigned int pci_bits; |
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u32 flags = 0; |
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|
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/* Account for "normal" resources to lock. If we decode the legacy, |
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* counterpart, we need to request it as well |
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*/ |
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if ((rsrc & VGA_RSRC_NORMAL_IO) && |
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(vgadev->decodes & VGA_RSRC_LEGACY_IO)) |
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rsrc |= VGA_RSRC_LEGACY_IO; |
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if ((rsrc & VGA_RSRC_NORMAL_MEM) && |
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(vgadev->decodes & VGA_RSRC_LEGACY_MEM)) |
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rsrc |= VGA_RSRC_LEGACY_MEM; |
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|
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vgaarb_dbg(dev, "%s: %d\n", __func__, rsrc); |
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vgaarb_dbg(dev, "%s: owns: %d\n", __func__, vgadev->owns); |
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|
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/* Check what resources we need to acquire */ |
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wants = rsrc & ~vgadev->owns; |
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|
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/* We already own everything, just mark locked & bye bye */ |
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if (wants == 0) |
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goto lock_them; |
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|
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/* We don't need to request a legacy resource, we just enable |
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* appropriate decoding and go |
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*/ |
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legacy_wants = wants & VGA_RSRC_LEGACY_MASK; |
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if (legacy_wants == 0) |
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goto enable_them; |
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|
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/* Ok, we don't, let's find out how we need to kick off */ |
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list_for_each_entry(conflict, &vga_list, list) { |
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unsigned int lwants = legacy_wants; |
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unsigned int change_bridge = 0; |
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|
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/* Don't conflict with myself */ |
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if (vgadev == conflict) |
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continue; |
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|
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/* We have a possible conflict. before we go further, we must |
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* check if we sit on the same bus as the conflicting device. |
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* if we don't, then we must tie both IO and MEM resources |
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* together since there is only a single bit controlling |
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* VGA forwarding on P2P bridges |
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*/ |
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if (vgadev->pdev->bus != conflict->pdev->bus) { |
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change_bridge = 1; |
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lwants = VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM; |
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} |
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|
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/* Check if the guy has a lock on the resource. If he does, |
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* return the conflicting entry |
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*/ |
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if (conflict->locks & lwants) |
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return conflict; |
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|
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/* Ok, now check if it owns the resource we want. We can |
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* lock resources that are not decoded, therefore a device |
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* can own resources it doesn't decode. |
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*/ |
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match = lwants & conflict->owns; |
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if (!match) |
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continue; |
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|
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/* looks like he doesn't have a lock, we can steal |
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* them from him |
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*/ |
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|
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flags = 0; |
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pci_bits = 0; |
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|
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/* If we can't control legacy resources via the bridge, we |
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* also need to disable normal decoding. |
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*/ |
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if (!conflict->bridge_has_one_vga) { |
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if ((match & conflict->decodes) & VGA_RSRC_LEGACY_MEM) |
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pci_bits |= PCI_COMMAND_MEMORY; |
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if ((match & conflict->decodes) & VGA_RSRC_LEGACY_IO) |
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pci_bits |= PCI_COMMAND_IO; |
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|
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if (pci_bits) |
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flags |= PCI_VGA_STATE_CHANGE_DECODES; |
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} |
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|
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if (change_bridge) |
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flags |= PCI_VGA_STATE_CHANGE_BRIDGE; |
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|
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pci_set_vga_state(conflict->pdev, false, pci_bits, flags); |
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conflict->owns &= ~match; |
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|
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/* If we disabled normal decoding, reflect it in owns */ |
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if (pci_bits & PCI_COMMAND_MEMORY) |
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conflict->owns &= ~VGA_RSRC_NORMAL_MEM; |
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if (pci_bits & PCI_COMMAND_IO) |
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conflict->owns &= ~VGA_RSRC_NORMAL_IO; |
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} |
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|
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enable_them: |
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/* ok dude, we got it, everybody conflicting has been disabled, let's |
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* enable us. Mark any bits in "owns" regardless of whether we |
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* decoded them. We can lock resources we don't decode, therefore |
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* we must track them via "owns". |
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*/ |
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flags = 0; |
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pci_bits = 0; |
|
|
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if (!vgadev->bridge_has_one_vga) { |
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flags |= PCI_VGA_STATE_CHANGE_DECODES; |
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if (wants & (VGA_RSRC_LEGACY_MEM|VGA_RSRC_NORMAL_MEM)) |
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pci_bits |= PCI_COMMAND_MEMORY; |
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if (wants & (VGA_RSRC_LEGACY_IO|VGA_RSRC_NORMAL_IO)) |
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pci_bits |= PCI_COMMAND_IO; |
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} |
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if (wants & VGA_RSRC_LEGACY_MASK) |
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flags |= PCI_VGA_STATE_CHANGE_BRIDGE; |
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|
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pci_set_vga_state(vgadev->pdev, true, pci_bits, flags); |
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|
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vgadev->owns |= wants; |
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lock_them: |
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vgadev->locks |= (rsrc & VGA_RSRC_LEGACY_MASK); |
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if (rsrc & VGA_RSRC_LEGACY_IO) |
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vgadev->io_lock_cnt++; |
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if (rsrc & VGA_RSRC_LEGACY_MEM) |
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vgadev->mem_lock_cnt++; |
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if (rsrc & VGA_RSRC_NORMAL_IO) |
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vgadev->io_norm_cnt++; |
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if (rsrc & VGA_RSRC_NORMAL_MEM) |
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vgadev->mem_norm_cnt++; |
|
|
|
return NULL; |
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} |
|
|
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static void __vga_put(struct vga_device *vgadev, unsigned int rsrc) |
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{ |
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struct device *dev = &vgadev->pdev->dev; |
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unsigned int old_locks = vgadev->locks; |
|
|
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vgaarb_dbg(dev, "%s\n", __func__); |
|
|
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/* Update our counters, and account for equivalent legacy resources |
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* if we decode them |
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*/ |
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if ((rsrc & VGA_RSRC_NORMAL_IO) && vgadev->io_norm_cnt > 0) { |
|
vgadev->io_norm_cnt--; |
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if (vgadev->decodes & VGA_RSRC_LEGACY_IO) |
|
rsrc |= VGA_RSRC_LEGACY_IO; |
|
} |
|
if ((rsrc & VGA_RSRC_NORMAL_MEM) && vgadev->mem_norm_cnt > 0) { |
|
vgadev->mem_norm_cnt--; |
|
if (vgadev->decodes & VGA_RSRC_LEGACY_MEM) |
|
rsrc |= VGA_RSRC_LEGACY_MEM; |
|
} |
|
if ((rsrc & VGA_RSRC_LEGACY_IO) && vgadev->io_lock_cnt > 0) |
|
vgadev->io_lock_cnt--; |
|
if ((rsrc & VGA_RSRC_LEGACY_MEM) && vgadev->mem_lock_cnt > 0) |
|
vgadev->mem_lock_cnt--; |
|
|
|
/* Just clear lock bits, we do lazy operations so we don't really |
|
* have to bother about anything else at this point |
|
*/ |
|
if (vgadev->io_lock_cnt == 0) |
|
vgadev->locks &= ~VGA_RSRC_LEGACY_IO; |
|
if (vgadev->mem_lock_cnt == 0) |
|
vgadev->locks &= ~VGA_RSRC_LEGACY_MEM; |
|
|
|
/* Kick the wait queue in case somebody was waiting if we actually |
|
* released something |
|
*/ |
|
if (old_locks != vgadev->locks) |
|
wake_up_all(&vga_wait_queue); |
|
} |
|
|
|
/** |
|
* vga_get - acquire & locks VGA resources |
|
* @pdev: pci device of the VGA card or NULL for the system default |
|
* @rsrc: bit mask of resources to acquire and lock |
|
* @interruptible: blocking should be interruptible by signals ? |
|
* |
|
* This function acquires VGA resources for the given card and mark those |
|
* resources locked. If the resource requested are "normal" (and not legacy) |
|
* resources, the arbiter will first check whether the card is doing legacy |
|
* decoding for that type of resource. If yes, the lock is "converted" into a |
|
* legacy resource lock. |
|
* |
|
* The arbiter will first look for all VGA cards that might conflict and disable |
|
* their IOs and/or Memory access, including VGA forwarding on P2P bridges if |
|
* necessary, so that the requested resources can be used. Then, the card is |
|
* marked as locking these resources and the IO and/or Memory accesses are |
|
* enabled on the card (including VGA forwarding on parent P2P bridges if any). |
|
* |
|
* This function will block if some conflicting card is already locking one of |
|
* the required resources (or any resource on a different bus segment, since P2P |
|
* bridges don't differentiate VGA memory and IO afaik). You can indicate |
|
* whether this blocking should be interruptible by a signal (for userland |
|
* interface) or not. |
|
* |
|
* Must not be called at interrupt time or in atomic context. If the card |
|
* already owns the resources, the function succeeds. Nested calls are |
|
* supported (a per-resource counter is maintained) |
|
* |
|
* On success, release the VGA resource again with vga_put(). |
|
* |
|
* Returns: |
|
* |
|
* 0 on success, negative error code on failure. |
|
*/ |
|
int vga_get(struct pci_dev *pdev, unsigned int rsrc, int interruptible) |
|
{ |
|
struct vga_device *vgadev, *conflict; |
|
unsigned long flags; |
|
wait_queue_entry_t wait; |
|
int rc = 0; |
|
|
|
vga_check_first_use(); |
|
/* The one who calls us should check for this, but lets be sure... */ |
|
if (pdev == NULL) |
|
pdev = vga_default_device(); |
|
if (pdev == NULL) |
|
return 0; |
|
|
|
for (;;) { |
|
spin_lock_irqsave(&vga_lock, flags); |
|
vgadev = vgadev_find(pdev); |
|
if (vgadev == NULL) { |
|
spin_unlock_irqrestore(&vga_lock, flags); |
|
rc = -ENODEV; |
|
break; |
|
} |
|
conflict = __vga_tryget(vgadev, rsrc); |
|
spin_unlock_irqrestore(&vga_lock, flags); |
|
if (conflict == NULL) |
|
break; |
|
|
|
|
|
/* We have a conflict, we wait until somebody kicks the |
|
* work queue. Currently we have one work queue that we |
|
* kick each time some resources are released, but it would |
|
* be fairly easy to have a per device one so that we only |
|
* need to attach to the conflicting device |
|
*/ |
|
init_waitqueue_entry(&wait, current); |
|
add_wait_queue(&vga_wait_queue, &wait); |
|
set_current_state(interruptible ? |
|
TASK_INTERRUPTIBLE : |
|
TASK_UNINTERRUPTIBLE); |
|
if (interruptible && signal_pending(current)) { |
|
__set_current_state(TASK_RUNNING); |
|
remove_wait_queue(&vga_wait_queue, &wait); |
|
rc = -ERESTARTSYS; |
|
break; |
|
} |
|
schedule(); |
|
remove_wait_queue(&vga_wait_queue, &wait); |
|
} |
|
return rc; |
|
} |
|
EXPORT_SYMBOL(vga_get); |
|
|
|
/** |
|
* vga_tryget - try to acquire & lock legacy VGA resources |
|
* @pdev: pci devivce of VGA card or NULL for system default |
|
* @rsrc: bit mask of resources to acquire and lock |
|
* |
|
* This function performs the same operation as vga_get(), but will return an |
|
* error (-EBUSY) instead of blocking if the resources are already locked by |
|
* another card. It can be called in any context |
|
* |
|
* On success, release the VGA resource again with vga_put(). |
|
* |
|
* Returns: |
|
* |
|
* 0 on success, negative error code on failure. |
|
*/ |
|
static int vga_tryget(struct pci_dev *pdev, unsigned int rsrc) |
|
{ |
|
struct vga_device *vgadev; |
|
unsigned long flags; |
|
int rc = 0; |
|
|
|
vga_check_first_use(); |
|
|
|
/* The one who calls us should check for this, but lets be sure... */ |
|
if (pdev == NULL) |
|
pdev = vga_default_device(); |
|
if (pdev == NULL) |
|
return 0; |
|
spin_lock_irqsave(&vga_lock, flags); |
|
vgadev = vgadev_find(pdev); |
|
if (vgadev == NULL) { |
|
rc = -ENODEV; |
|
goto bail; |
|
} |
|
if (__vga_tryget(vgadev, rsrc)) |
|
rc = -EBUSY; |
|
bail: |
|
spin_unlock_irqrestore(&vga_lock, flags); |
|
return rc; |
|
} |
|
|
|
/** |
|
* vga_put - release lock on legacy VGA resources |
|
* @pdev: pci device of VGA card or NULL for system default |
|
* @rsrc: but mask of resource to release |
|
* |
|
* This fuction releases resources previously locked by vga_get() or |
|
* vga_tryget(). The resources aren't disabled right away, so that a subsequence |
|
* vga_get() on the same card will succeed immediately. Resources have a |
|
* counter, so locks are only released if the counter reaches 0. |
|
*/ |
|
void vga_put(struct pci_dev *pdev, unsigned int rsrc) |
|
{ |
|
struct vga_device *vgadev; |
|
unsigned long flags; |
|
|
|
/* The one who calls us should check for this, but lets be sure... */ |
|
if (pdev == NULL) |
|
pdev = vga_default_device(); |
|
if (pdev == NULL) |
|
return; |
|
spin_lock_irqsave(&vga_lock, flags); |
|
vgadev = vgadev_find(pdev); |
|
if (vgadev == NULL) |
|
goto bail; |
|
__vga_put(vgadev, rsrc); |
|
bail: |
|
spin_unlock_irqrestore(&vga_lock, flags); |
|
} |
|
EXPORT_SYMBOL(vga_put); |
|
|
|
/* |
|
* Rules for using a bridge to control a VGA descendant decoding: if a bridge |
|
* has only one VGA descendant then it can be used to control the VGA routing |
|
* for that device. It should always use the bridge closest to the device to |
|
* control it. If a bridge has a direct VGA descendant, but also have a sub- |
|
* bridge VGA descendant then we cannot use that bridge to control the direct |
|
* VGA descendant. So for every device we register, we need to iterate all |
|
* its parent bridges so we can invalidate any devices using them properly. |
|
*/ |
|
static void vga_arbiter_check_bridge_sharing(struct vga_device *vgadev) |
|
{ |
|
struct vga_device *same_bridge_vgadev; |
|
struct pci_bus *new_bus, *bus; |
|
struct pci_dev *new_bridge, *bridge; |
|
|
|
vgadev->bridge_has_one_vga = true; |
|
|
|
if (list_empty(&vga_list)) |
|
return; |
|
|
|
/* okay iterate the new devices bridge hierarachy */ |
|
new_bus = vgadev->pdev->bus; |
|
while (new_bus) { |
|
new_bridge = new_bus->self; |
|
|
|
/* go through list of devices already registered */ |
|
list_for_each_entry(same_bridge_vgadev, &vga_list, list) { |
|
bus = same_bridge_vgadev->pdev->bus; |
|
bridge = bus->self; |
|
|
|
/* see if the share a bridge with this device */ |
|
if (new_bridge == bridge) { |
|
/* |
|
* If their direct parent bridge is the same |
|
* as any bridge of this device then it can't |
|
* be used for that device. |
|
*/ |
|
same_bridge_vgadev->bridge_has_one_vga = false; |
|
} |
|
|
|
/* |
|
* Now iterate the previous devices bridge hierarchy. |
|
* If the new devices parent bridge is in the other |
|
* devices hierarchy then we can't use it to control |
|
* this device |
|
*/ |
|
while (bus) { |
|
bridge = bus->self; |
|
|
|
if (bridge && bridge == vgadev->pdev->bus->self) |
|
vgadev->bridge_has_one_vga = false; |
|
|
|
bus = bus->parent; |
|
} |
|
} |
|
new_bus = new_bus->parent; |
|
} |
|
} |
|
|
|
/* |
|
* Currently, we assume that the "initial" setup of the system is |
|
* not sane, that is we come up with conflicting devices and let |
|
* the arbiter's client decides if devices decodes or not legacy |
|
* things. |
|
*/ |
|
static bool vga_arbiter_add_pci_device(struct pci_dev *pdev) |
|
{ |
|
struct vga_device *vgadev; |
|
unsigned long flags; |
|
struct pci_bus *bus; |
|
struct pci_dev *bridge; |
|
u16 cmd; |
|
|
|
/* Only deal with VGA class devices */ |
|
if ((pdev->class >> 8) != PCI_CLASS_DISPLAY_VGA) |
|
return false; |
|
|
|
/* Allocate structure */ |
|
vgadev = kzalloc(sizeof(struct vga_device), GFP_KERNEL); |
|
if (vgadev == NULL) { |
|
vgaarb_err(&pdev->dev, "failed to allocate VGA arbiter data\n"); |
|
/* |
|
* What to do on allocation failure ? For now, let's just do |
|
* nothing, I'm not sure there is anything saner to be done. |
|
*/ |
|
return false; |
|
} |
|
|
|
/* Take lock & check for duplicates */ |
|
spin_lock_irqsave(&vga_lock, flags); |
|
if (vgadev_find(pdev) != NULL) { |
|
BUG_ON(1); |
|
goto fail; |
|
} |
|
vgadev->pdev = pdev; |
|
|
|
/* By default, assume we decode everything */ |
|
vgadev->decodes = VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM | |
|
VGA_RSRC_NORMAL_IO | VGA_RSRC_NORMAL_MEM; |
|
|
|
/* by default mark it as decoding */ |
|
vga_decode_count++; |
|
/* Mark that we "own" resources based on our enables, we will |
|
* clear that below if the bridge isn't forwarding |
|
*/ |
|
pci_read_config_word(pdev, PCI_COMMAND, &cmd); |
|
if (cmd & PCI_COMMAND_IO) |
|
vgadev->owns |= VGA_RSRC_LEGACY_IO; |
|
if (cmd & PCI_COMMAND_MEMORY) |
|
vgadev->owns |= VGA_RSRC_LEGACY_MEM; |
|
|
|
/* Check if VGA cycles can get down to us */ |
|
bus = pdev->bus; |
|
while (bus) { |
|
bridge = bus->self; |
|
if (bridge) { |
|
u16 l; |
|
|
|
pci_read_config_word(bridge, PCI_BRIDGE_CONTROL, &l); |
|
if (!(l & PCI_BRIDGE_CTL_VGA)) { |
|
vgadev->owns = 0; |
|
break; |
|
} |
|
} |
|
bus = bus->parent; |
|
} |
|
|
|
/* Deal with VGA default device. Use first enabled one |
|
* by default if arch doesn't have it's own hook |
|
*/ |
|
if (vga_default == NULL && |
|
((vgadev->owns & VGA_RSRC_LEGACY_MASK) == VGA_RSRC_LEGACY_MASK)) { |
|
vgaarb_info(&pdev->dev, "setting as boot VGA device\n"); |
|
vga_set_default_device(pdev); |
|
} |
|
|
|
vga_arbiter_check_bridge_sharing(vgadev); |
|
|
|
/* Add to the list */ |
|
list_add_tail(&vgadev->list, &vga_list); |
|
vga_count++; |
|
vgaarb_info(&pdev->dev, "VGA device added: decodes=%s,owns=%s,locks=%s\n", |
|
vga_iostate_to_str(vgadev->decodes), |
|
vga_iostate_to_str(vgadev->owns), |
|
vga_iostate_to_str(vgadev->locks)); |
|
|
|
spin_unlock_irqrestore(&vga_lock, flags); |
|
return true; |
|
fail: |
|
spin_unlock_irqrestore(&vga_lock, flags); |
|
kfree(vgadev); |
|
return false; |
|
} |
|
|
|
static bool vga_arbiter_del_pci_device(struct pci_dev *pdev) |
|
{ |
|
struct vga_device *vgadev; |
|
unsigned long flags; |
|
bool ret = true; |
|
|
|
spin_lock_irqsave(&vga_lock, flags); |
|
vgadev = vgadev_find(pdev); |
|
if (vgadev == NULL) { |
|
ret = false; |
|
goto bail; |
|
} |
|
|
|
if (vga_default == pdev) |
|
vga_set_default_device(NULL); |
|
|
|
if (vgadev->decodes & (VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM)) |
|
vga_decode_count--; |
|
|
|
/* Remove entry from list */ |
|
list_del(&vgadev->list); |
|
vga_count--; |
|
/* Notify userland driver that the device is gone so it discards |
|
* it's copies of the pci_dev pointer |
|
*/ |
|
vga_arb_device_card_gone(pdev); |
|
|
|
/* Wake up all possible waiters */ |
|
wake_up_all(&vga_wait_queue); |
|
bail: |
|
spin_unlock_irqrestore(&vga_lock, flags); |
|
kfree(vgadev); |
|
return ret; |
|
} |
|
|
|
/* this is called with the lock */ |
|
static inline void vga_update_device_decodes(struct vga_device *vgadev, |
|
int new_decodes) |
|
{ |
|
struct device *dev = &vgadev->pdev->dev; |
|
int old_decodes, decodes_removed, decodes_unlocked; |
|
|
|
old_decodes = vgadev->decodes; |
|
decodes_removed = ~new_decodes & old_decodes; |
|
decodes_unlocked = vgadev->locks & decodes_removed; |
|
vgadev->decodes = new_decodes; |
|
|
|
vgaarb_info(dev, "changed VGA decodes: olddecodes=%s,decodes=%s:owns=%s\n", |
|
vga_iostate_to_str(old_decodes), |
|
vga_iostate_to_str(vgadev->decodes), |
|
vga_iostate_to_str(vgadev->owns)); |
|
|
|
/* if we removed locked decodes, lock count goes to zero, and release */ |
|
if (decodes_unlocked) { |
|
if (decodes_unlocked & VGA_RSRC_LEGACY_IO) |
|
vgadev->io_lock_cnt = 0; |
|
if (decodes_unlocked & VGA_RSRC_LEGACY_MEM) |
|
vgadev->mem_lock_cnt = 0; |
|
__vga_put(vgadev, decodes_unlocked); |
|
} |
|
|
|
/* change decodes counter */ |
|
if (old_decodes & VGA_RSRC_LEGACY_MASK && |
|
!(new_decodes & VGA_RSRC_LEGACY_MASK)) |
|
vga_decode_count--; |
|
if (!(old_decodes & VGA_RSRC_LEGACY_MASK) && |
|
new_decodes & VGA_RSRC_LEGACY_MASK) |
|
vga_decode_count++; |
|
vgaarb_dbg(dev, "decoding count now is: %d\n", vga_decode_count); |
|
} |
|
|
|
static void __vga_set_legacy_decoding(struct pci_dev *pdev, |
|
unsigned int decodes, |
|
bool userspace) |
|
{ |
|
struct vga_device *vgadev; |
|
unsigned long flags; |
|
|
|
decodes &= VGA_RSRC_LEGACY_MASK; |
|
|
|
spin_lock_irqsave(&vga_lock, flags); |
|
vgadev = vgadev_find(pdev); |
|
if (vgadev == NULL) |
|
goto bail; |
|
|
|
/* don't let userspace futz with kernel driver decodes */ |
|
if (userspace && vgadev->set_decode) |
|
goto bail; |
|
|
|
/* update the device decodes + counter */ |
|
vga_update_device_decodes(vgadev, decodes); |
|
|
|
/* XXX if somebody is going from "doesn't decode" to "decodes" state |
|
* here, additional care must be taken as we may have pending owner |
|
* ship of non-legacy region ... |
|
*/ |
|
bail: |
|
spin_unlock_irqrestore(&vga_lock, flags); |
|
} |
|
|
|
/** |
|
* vga_set_legacy_decoding |
|
* @pdev: pci device of the VGA card |
|
* @decodes: bit mask of what legacy regions the card decodes |
|
* |
|
* Indicates to the arbiter if the card decodes legacy VGA IOs, legacy VGA |
|
* Memory, both, or none. All cards default to both, the card driver (fbdev for |
|
* example) should tell the arbiter if it has disabled legacy decoding, so the |
|
* card can be left out of the arbitration process (and can be safe to take |
|
* interrupts at any time. |
|
*/ |
|
void vga_set_legacy_decoding(struct pci_dev *pdev, unsigned int decodes) |
|
{ |
|
__vga_set_legacy_decoding(pdev, decodes, false); |
|
} |
|
EXPORT_SYMBOL(vga_set_legacy_decoding); |
|
|
|
/** |
|
* vga_client_register - register or unregister a VGA arbitration client |
|
* @pdev: pci device of the VGA client |
|
* @set_decode: vga decode change callback |
|
* |
|
* Clients have two callback mechanisms they can use. |
|
* |
|
* @set_decode callback: If a client can disable its GPU VGA resource, it |
|
* will get a callback from this to set the encode/decode state. |
|
* |
|
* Rationale: we cannot disable VGA decode resources unconditionally some single |
|
* GPU laptops seem to require ACPI or BIOS access to the VGA registers to |
|
* control things like backlights etc. Hopefully newer multi-GPU laptops do |
|
* something saner, and desktops won't have any special ACPI for this. The |
|
* driver will get a callback when VGA arbitration is first used by userspace |
|
* since some older X servers have issues. |
|
* |
|
* This function does not check whether a client for @pdev has been registered |
|
* already. |
|
* |
|
* To unregister just call vga_client_unregister(). |
|
* |
|
* Returns: 0 on success, -1 on failure |
|
*/ |
|
int vga_client_register(struct pci_dev *pdev, |
|
unsigned int (*set_decode)(struct pci_dev *pdev, bool decode)) |
|
{ |
|
int ret = -ENODEV; |
|
struct vga_device *vgadev; |
|
unsigned long flags; |
|
|
|
spin_lock_irqsave(&vga_lock, flags); |
|
vgadev = vgadev_find(pdev); |
|
if (!vgadev) |
|
goto bail; |
|
|
|
vgadev->set_decode = set_decode; |
|
ret = 0; |
|
|
|
bail: |
|
spin_unlock_irqrestore(&vga_lock, flags); |
|
return ret; |
|
|
|
} |
|
EXPORT_SYMBOL(vga_client_register); |
|
|
|
/* |
|
* Char driver implementation |
|
* |
|
* Semantics is: |
|
* |
|
* open : open user instance of the arbitrer. by default, it's |
|
* attached to the default VGA device of the system. |
|
* |
|
* close : close user instance, release locks |
|
* |
|
* read : return a string indicating the status of the target. |
|
* an IO state string is of the form {io,mem,io+mem,none}, |
|
* mc and ic are respectively mem and io lock counts (for |
|
* debugging/diagnostic only). "decodes" indicate what the |
|
* card currently decodes, "owns" indicates what is currently |
|
* enabled on it, and "locks" indicates what is locked by this |
|
* card. If the card is unplugged, we get "invalid" then for |
|
* card_ID and an -ENODEV error is returned for any command |
|
* until a new card is targeted |
|
* |
|
* "<card_ID>,decodes=<io_state>,owns=<io_state>,locks=<io_state> (ic,mc)" |
|
* |
|
* write : write a command to the arbiter. List of commands is: |
|
* |
|
* target <card_ID> : switch target to card <card_ID> (see below) |
|
* lock <io_state> : acquires locks on target ("none" is invalid io_state) |
|
* trylock <io_state> : non-blocking acquire locks on target |
|
* unlock <io_state> : release locks on target |
|
* unlock all : release all locks on target held by this user |
|
* decodes <io_state> : set the legacy decoding attributes for the card |
|
* |
|
* poll : event if something change on any card (not just the target) |
|
* |
|
* card_ID is of the form "PCI:domain:bus:dev.fn". It can be set to "default" |
|
* to go back to the system default card (TODO: not implemented yet). |
|
* Currently, only PCI is supported as a prefix, but the userland API may |
|
* support other bus types in the future, even if the current kernel |
|
* implementation doesn't. |
|
* |
|
* Note about locks: |
|
* |
|
* The driver keeps track of which user has what locks on which card. It |
|
* supports stacking, like the kernel one. This complexifies the implementation |
|
* a bit, but makes the arbiter more tolerant to userspace problems and able |
|
* to properly cleanup in all cases when a process dies. |
|
* Currently, a max of 16 cards simultaneously can have locks issued from |
|
* userspace for a given user (file descriptor instance) of the arbiter. |
|
* |
|
* If the device is hot-unplugged, there is a hook inside the module to notify |
|
* they being added/removed in the system and automatically added/removed in |
|
* the arbiter. |
|
*/ |
|
|
|
#define MAX_USER_CARDS CONFIG_VGA_ARB_MAX_GPUS |
|
#define PCI_INVALID_CARD ((struct pci_dev *)-1UL) |
|
|
|
/* |
|
* Each user has an array of these, tracking which cards have locks |
|
*/ |
|
struct vga_arb_user_card { |
|
struct pci_dev *pdev; |
|
unsigned int mem_cnt; |
|
unsigned int io_cnt; |
|
}; |
|
|
|
struct vga_arb_private { |
|
struct list_head list; |
|
struct pci_dev *target; |
|
struct vga_arb_user_card cards[MAX_USER_CARDS]; |
|
spinlock_t lock; |
|
}; |
|
|
|
static LIST_HEAD(vga_user_list); |
|
static DEFINE_SPINLOCK(vga_user_lock); |
|
|
|
|
|
/* |
|
* This function gets a string in the format: "PCI:domain:bus:dev.fn" and |
|
* returns the respective values. If the string is not in this format, |
|
* it returns 0. |
|
*/ |
|
static int vga_pci_str_to_vars(char *buf, int count, unsigned int *domain, |
|
unsigned int *bus, unsigned int *devfn) |
|
{ |
|
int n; |
|
unsigned int slot, func; |
|
|
|
|
|
n = sscanf(buf, "PCI:%x:%x:%x.%x", domain, bus, &slot, &func); |
|
if (n != 4) |
|
return 0; |
|
|
|
*devfn = PCI_DEVFN(slot, func); |
|
|
|
return 1; |
|
} |
|
|
|
static ssize_t vga_arb_read(struct file *file, char __user *buf, |
|
size_t count, loff_t *ppos) |
|
{ |
|
struct vga_arb_private *priv = file->private_data; |
|
struct vga_device *vgadev; |
|
struct pci_dev *pdev; |
|
unsigned long flags; |
|
size_t len; |
|
int rc; |
|
char *lbuf; |
|
|
|
lbuf = kmalloc(1024, GFP_KERNEL); |
|
if (lbuf == NULL) |
|
return -ENOMEM; |
|
|
|
/* Shields against vga_arb_device_card_gone (pci_dev going |
|
* away), and allows access to vga list |
|
*/ |
|
spin_lock_irqsave(&vga_lock, flags); |
|
|
|
/* If we are targeting the default, use it */ |
|
pdev = priv->target; |
|
if (pdev == NULL || pdev == PCI_INVALID_CARD) { |
|
spin_unlock_irqrestore(&vga_lock, flags); |
|
len = sprintf(lbuf, "invalid"); |
|
goto done; |
|
} |
|
|
|
/* Find card vgadev structure */ |
|
vgadev = vgadev_find(pdev); |
|
if (vgadev == NULL) { |
|
/* Wow, it's not in the list, that shouldn't happen, |
|
* let's fix us up and return invalid card |
|
*/ |
|
if (pdev == priv->target) |
|
vga_arb_device_card_gone(pdev); |
|
spin_unlock_irqrestore(&vga_lock, flags); |
|
len = sprintf(lbuf, "invalid"); |
|
goto done; |
|
} |
|
|
|
/* Fill the buffer with infos */ |
|
len = snprintf(lbuf, 1024, |
|
"count:%d,PCI:%s,decodes=%s,owns=%s,locks=%s(%d:%d)\n", |
|
vga_decode_count, pci_name(pdev), |
|
vga_iostate_to_str(vgadev->decodes), |
|
vga_iostate_to_str(vgadev->owns), |
|
vga_iostate_to_str(vgadev->locks), |
|
vgadev->io_lock_cnt, vgadev->mem_lock_cnt); |
|
|
|
spin_unlock_irqrestore(&vga_lock, flags); |
|
done: |
|
|
|
/* Copy that to user */ |
|
if (len > count) |
|
len = count; |
|
rc = copy_to_user(buf, lbuf, len); |
|
kfree(lbuf); |
|
if (rc) |
|
return -EFAULT; |
|
return len; |
|
} |
|
|
|
/* |
|
* TODO: To avoid parsing inside kernel and to improve the speed we may |
|
* consider use ioctl here |
|
*/ |
|
static ssize_t vga_arb_write(struct file *file, const char __user *buf, |
|
size_t count, loff_t *ppos) |
|
{ |
|
struct vga_arb_private *priv = file->private_data; |
|
struct vga_arb_user_card *uc = NULL; |
|
struct pci_dev *pdev; |
|
|
|
unsigned int io_state; |
|
|
|
char kbuf[64], *curr_pos; |
|
size_t remaining = count; |
|
|
|
int ret_val; |
|
int i; |
|
|
|
if (count >= sizeof(kbuf)) |
|
return -EINVAL; |
|
if (copy_from_user(kbuf, buf, count)) |
|
return -EFAULT; |
|
curr_pos = kbuf; |
|
kbuf[count] = '\0'; /* Just to make sure... */ |
|
|
|
if (strncmp(curr_pos, "lock ", 5) == 0) { |
|
curr_pos += 5; |
|
remaining -= 5; |
|
|
|
pr_debug("client 0x%p called 'lock'\n", priv); |
|
|
|
if (!vga_str_to_iostate(curr_pos, remaining, &io_state)) { |
|
ret_val = -EPROTO; |
|
goto done; |
|
} |
|
if (io_state == VGA_RSRC_NONE) { |
|
ret_val = -EPROTO; |
|
goto done; |
|
} |
|
|
|
pdev = priv->target; |
|
if (priv->target == NULL) { |
|
ret_val = -ENODEV; |
|
goto done; |
|
} |
|
|
|
vga_get_uninterruptible(pdev, io_state); |
|
|
|
/* Update the client's locks lists... */ |
|
for (i = 0; i < MAX_USER_CARDS; i++) { |
|
if (priv->cards[i].pdev == pdev) { |
|
if (io_state & VGA_RSRC_LEGACY_IO) |
|
priv->cards[i].io_cnt++; |
|
if (io_state & VGA_RSRC_LEGACY_MEM) |
|
priv->cards[i].mem_cnt++; |
|
break; |
|
} |
|
} |
|
|
|
ret_val = count; |
|
goto done; |
|
} else if (strncmp(curr_pos, "unlock ", 7) == 0) { |
|
curr_pos += 7; |
|
remaining -= 7; |
|
|
|
pr_debug("client 0x%p called 'unlock'\n", priv); |
|
|
|
if (strncmp(curr_pos, "all", 3) == 0) |
|
io_state = VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM; |
|
else { |
|
if (!vga_str_to_iostate |
|
(curr_pos, remaining, &io_state)) { |
|
ret_val = -EPROTO; |
|
goto done; |
|
} |
|
/* TODO: Add this? |
|
if (io_state == VGA_RSRC_NONE) { |
|
ret_val = -EPROTO; |
|
goto done; |
|
} |
|
*/ |
|
} |
|
|
|
pdev = priv->target; |
|
if (priv->target == NULL) { |
|
ret_val = -ENODEV; |
|
goto done; |
|
} |
|
for (i = 0; i < MAX_USER_CARDS; i++) { |
|
if (priv->cards[i].pdev == pdev) |
|
uc = &priv->cards[i]; |
|
} |
|
|
|
if (!uc) { |
|
ret_val = -EINVAL; |
|
goto done; |
|
} |
|
|
|
if (io_state & VGA_RSRC_LEGACY_IO && uc->io_cnt == 0) { |
|
ret_val = -EINVAL; |
|
goto done; |
|
} |
|
|
|
if (io_state & VGA_RSRC_LEGACY_MEM && uc->mem_cnt == 0) { |
|
ret_val = -EINVAL; |
|
goto done; |
|
} |
|
|
|
vga_put(pdev, io_state); |
|
|
|
if (io_state & VGA_RSRC_LEGACY_IO) |
|
uc->io_cnt--; |
|
if (io_state & VGA_RSRC_LEGACY_MEM) |
|
uc->mem_cnt--; |
|
|
|
ret_val = count; |
|
goto done; |
|
} else if (strncmp(curr_pos, "trylock ", 8) == 0) { |
|
curr_pos += 8; |
|
remaining -= 8; |
|
|
|
pr_debug("client 0x%p called 'trylock'\n", priv); |
|
|
|
if (!vga_str_to_iostate(curr_pos, remaining, &io_state)) { |
|
ret_val = -EPROTO; |
|
goto done; |
|
} |
|
/* TODO: Add this? |
|
if (io_state == VGA_RSRC_NONE) { |
|
ret_val = -EPROTO; |
|
goto done; |
|
} |
|
*/ |
|
|
|
pdev = priv->target; |
|
if (priv->target == NULL) { |
|
ret_val = -ENODEV; |
|
goto done; |
|
} |
|
|
|
if (vga_tryget(pdev, io_state)) { |
|
/* Update the client's locks lists... */ |
|
for (i = 0; i < MAX_USER_CARDS; i++) { |
|
if (priv->cards[i].pdev == pdev) { |
|
if (io_state & VGA_RSRC_LEGACY_IO) |
|
priv->cards[i].io_cnt++; |
|
if (io_state & VGA_RSRC_LEGACY_MEM) |
|
priv->cards[i].mem_cnt++; |
|
break; |
|
} |
|
} |
|
ret_val = count; |
|
goto done; |
|
} else { |
|
ret_val = -EBUSY; |
|
goto done; |
|
} |
|
|
|
} else if (strncmp(curr_pos, "target ", 7) == 0) { |
|
unsigned int domain, bus, devfn; |
|
struct vga_device *vgadev; |
|
|
|
curr_pos += 7; |
|
remaining -= 7; |
|
pr_debug("client 0x%p called 'target'\n", priv); |
|
/* if target is default */ |
|
if (!strncmp(curr_pos, "default", 7)) |
|
pdev = pci_dev_get(vga_default_device()); |
|
else { |
|
if (!vga_pci_str_to_vars(curr_pos, remaining, |
|
&domain, &bus, &devfn)) { |
|
ret_val = -EPROTO; |
|
goto done; |
|
} |
|
pdev = pci_get_domain_bus_and_slot(domain, bus, devfn); |
|
if (!pdev) { |
|
pr_debug("invalid PCI address %04x:%02x:%02x.%x\n", |
|
domain, bus, PCI_SLOT(devfn), |
|
PCI_FUNC(devfn)); |
|
ret_val = -ENODEV; |
|
goto done; |
|
} |
|
|
|
pr_debug("%s ==> %04x:%02x:%02x.%x pdev %p\n", curr_pos, |
|
domain, bus, PCI_SLOT(devfn), PCI_FUNC(devfn), |
|
pdev); |
|
} |
|
|
|
vgadev = vgadev_find(pdev); |
|
pr_debug("vgadev %p\n", vgadev); |
|
if (vgadev == NULL) { |
|
if (pdev) { |
|
vgaarb_dbg(&pdev->dev, "not a VGA device\n"); |
|
pci_dev_put(pdev); |
|
} |
|
|
|
ret_val = -ENODEV; |
|
goto done; |
|
} |
|
|
|
priv->target = pdev; |
|
for (i = 0; i < MAX_USER_CARDS; i++) { |
|
if (priv->cards[i].pdev == pdev) |
|
break; |
|
if (priv->cards[i].pdev == NULL) { |
|
priv->cards[i].pdev = pdev; |
|
priv->cards[i].io_cnt = 0; |
|
priv->cards[i].mem_cnt = 0; |
|
break; |
|
} |
|
} |
|
if (i == MAX_USER_CARDS) { |
|
vgaarb_dbg(&pdev->dev, "maximum user cards (%d) number reached, ignoring this one!\n", |
|
MAX_USER_CARDS); |
|
pci_dev_put(pdev); |
|
/* XXX: which value to return? */ |
|
ret_val = -ENOMEM; |
|
goto done; |
|
} |
|
|
|
ret_val = count; |
|
pci_dev_put(pdev); |
|
goto done; |
|
|
|
|
|
} else if (strncmp(curr_pos, "decodes ", 8) == 0) { |
|
curr_pos += 8; |
|
remaining -= 8; |
|
pr_debug("client 0x%p called 'decodes'\n", priv); |
|
|
|
if (!vga_str_to_iostate(curr_pos, remaining, &io_state)) { |
|
ret_val = -EPROTO; |
|
goto done; |
|
} |
|
pdev = priv->target; |
|
if (priv->target == NULL) { |
|
ret_val = -ENODEV; |
|
goto done; |
|
} |
|
|
|
__vga_set_legacy_decoding(pdev, io_state, true); |
|
ret_val = count; |
|
goto done; |
|
} |
|
/* If we got here, the message written is not part of the protocol! */ |
|
return -EPROTO; |
|
|
|
done: |
|
return ret_val; |
|
} |
|
|
|
static __poll_t vga_arb_fpoll(struct file *file, poll_table *wait) |
|
{ |
|
pr_debug("%s\n", __func__); |
|
|
|
poll_wait(file, &vga_wait_queue, wait); |
|
return EPOLLIN; |
|
} |
|
|
|
static int vga_arb_open(struct inode *inode, struct file *file) |
|
{ |
|
struct vga_arb_private *priv; |
|
unsigned long flags; |
|
|
|
pr_debug("%s\n", __func__); |
|
|
|
priv = kzalloc(sizeof(*priv), GFP_KERNEL); |
|
if (priv == NULL) |
|
return -ENOMEM; |
|
spin_lock_init(&priv->lock); |
|
file->private_data = priv; |
|
|
|
spin_lock_irqsave(&vga_user_lock, flags); |
|
list_add(&priv->list, &vga_user_list); |
|
spin_unlock_irqrestore(&vga_user_lock, flags); |
|
|
|
/* Set the client' lists of locks */ |
|
priv->target = vga_default_device(); /* Maybe this is still null! */ |
|
priv->cards[0].pdev = priv->target; |
|
priv->cards[0].io_cnt = 0; |
|
priv->cards[0].mem_cnt = 0; |
|
|
|
|
|
return 0; |
|
} |
|
|
|
static int vga_arb_release(struct inode *inode, struct file *file) |
|
{ |
|
struct vga_arb_private *priv = file->private_data; |
|
struct vga_arb_user_card *uc; |
|
unsigned long flags; |
|
int i; |
|
|
|
pr_debug("%s\n", __func__); |
|
|
|
spin_lock_irqsave(&vga_user_lock, flags); |
|
list_del(&priv->list); |
|
for (i = 0; i < MAX_USER_CARDS; i++) { |
|
uc = &priv->cards[i]; |
|
if (uc->pdev == NULL) |
|
continue; |
|
vgaarb_dbg(&uc->pdev->dev, "uc->io_cnt == %d, uc->mem_cnt == %d\n", |
|
uc->io_cnt, uc->mem_cnt); |
|
while (uc->io_cnt--) |
|
vga_put(uc->pdev, VGA_RSRC_LEGACY_IO); |
|
while (uc->mem_cnt--) |
|
vga_put(uc->pdev, VGA_RSRC_LEGACY_MEM); |
|
} |
|
spin_unlock_irqrestore(&vga_user_lock, flags); |
|
|
|
kfree(priv); |
|
|
|
return 0; |
|
} |
|
|
|
static void vga_arb_device_card_gone(struct pci_dev *pdev) |
|
{ |
|
} |
|
|
|
/* |
|
* callback any registered clients to let them know we have a |
|
* change in VGA cards |
|
*/ |
|
static void vga_arbiter_notify_clients(void) |
|
{ |
|
struct vga_device *vgadev; |
|
unsigned long flags; |
|
uint32_t new_decodes; |
|
bool new_state; |
|
|
|
if (!vga_arbiter_used) |
|
return; |
|
|
|
spin_lock_irqsave(&vga_lock, flags); |
|
list_for_each_entry(vgadev, &vga_list, list) { |
|
if (vga_count > 1) |
|
new_state = false; |
|
else |
|
new_state = true; |
|
if (vgadev->set_decode) { |
|
new_decodes = vgadev->set_decode(vgadev->pdev, |
|
new_state); |
|
vga_update_device_decodes(vgadev, new_decodes); |
|
} |
|
} |
|
spin_unlock_irqrestore(&vga_lock, flags); |
|
} |
|
|
|
static int pci_notify(struct notifier_block *nb, unsigned long action, |
|
void *data) |
|
{ |
|
struct device *dev = data; |
|
struct pci_dev *pdev = to_pci_dev(dev); |
|
bool notify = false; |
|
|
|
vgaarb_dbg(dev, "%s\n", __func__); |
|
|
|
/* For now we're only intereted in devices added and removed. I didn't |
|
* test this thing here, so someone needs to double check for the |
|
* cases of hotplugable vga cards. */ |
|
if (action == BUS_NOTIFY_ADD_DEVICE) |
|
notify = vga_arbiter_add_pci_device(pdev); |
|
else if (action == BUS_NOTIFY_DEL_DEVICE) |
|
notify = vga_arbiter_del_pci_device(pdev); |
|
|
|
if (notify) |
|
vga_arbiter_notify_clients(); |
|
return 0; |
|
} |
|
|
|
static struct notifier_block pci_notifier = { |
|
.notifier_call = pci_notify, |
|
}; |
|
|
|
static const struct file_operations vga_arb_device_fops = { |
|
.read = vga_arb_read, |
|
.write = vga_arb_write, |
|
.poll = vga_arb_fpoll, |
|
.open = vga_arb_open, |
|
.release = vga_arb_release, |
|
.llseek = noop_llseek, |
|
}; |
|
|
|
static struct miscdevice vga_arb_device = { |
|
MISC_DYNAMIC_MINOR, "vga_arbiter", &vga_arb_device_fops |
|
}; |
|
|
|
#if defined(CONFIG_ACPI) |
|
static bool vga_arb_integrated_gpu(struct device *dev) |
|
{ |
|
struct acpi_device *adev = ACPI_COMPANION(dev); |
|
|
|
return adev && !strcmp(acpi_device_hid(adev), ACPI_VIDEO_HID); |
|
} |
|
#else |
|
static bool vga_arb_integrated_gpu(struct device *dev) |
|
{ |
|
return false; |
|
} |
|
#endif |
|
|
|
static void __init vga_arb_select_default_device(void) |
|
{ |
|
struct pci_dev *pdev, *found = NULL; |
|
struct vga_device *vgadev; |
|
|
|
#if defined(CONFIG_X86) || defined(CONFIG_IA64) |
|
u64 base = screen_info.lfb_base; |
|
u64 size = screen_info.lfb_size; |
|
u64 limit; |
|
resource_size_t start, end; |
|
unsigned long flags; |
|
int i; |
|
|
|
if (screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE) |
|
base |= (u64)screen_info.ext_lfb_base << 32; |
|
|
|
limit = base + size; |
|
|
|
list_for_each_entry(vgadev, &vga_list, list) { |
|
struct device *dev = &vgadev->pdev->dev; |
|
/* |
|
* Override vga_arbiter_add_pci_device()'s I/O based detection |
|
* as it may take the wrong device (e.g. on Apple system under |
|
* EFI). |
|
* |
|
* Select the device owning the boot framebuffer if there is |
|
* one. |
|
*/ |
|
|
|
/* Does firmware framebuffer belong to us? */ |
|
for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) { |
|
flags = pci_resource_flags(vgadev->pdev, i); |
|
|
|
if ((flags & IORESOURCE_MEM) == 0) |
|
continue; |
|
|
|
start = pci_resource_start(vgadev->pdev, i); |
|
end = pci_resource_end(vgadev->pdev, i); |
|
|
|
if (!start || !end) |
|
continue; |
|
|
|
if (base < start || limit >= end) |
|
continue; |
|
|
|
if (!vga_default_device()) |
|
vgaarb_info(dev, "setting as boot device\n"); |
|
else if (vgadev->pdev != vga_default_device()) |
|
vgaarb_info(dev, "overriding boot device\n"); |
|
vga_set_default_device(vgadev->pdev); |
|
} |
|
} |
|
#endif |
|
|
|
if (!vga_default_device()) { |
|
list_for_each_entry_reverse(vgadev, &vga_list, list) { |
|
struct device *dev = &vgadev->pdev->dev; |
|
u16 cmd; |
|
|
|
pdev = vgadev->pdev; |
|
pci_read_config_word(pdev, PCI_COMMAND, &cmd); |
|
if (cmd & (PCI_COMMAND_IO | PCI_COMMAND_MEMORY)) { |
|
found = pdev; |
|
if (vga_arb_integrated_gpu(dev)) |
|
break; |
|
} |
|
} |
|
} |
|
|
|
if (found) { |
|
vgaarb_info(&found->dev, "setting as boot device (VGA legacy resources not available)\n"); |
|
vga_set_default_device(found); |
|
return; |
|
} |
|
|
|
if (!vga_default_device()) { |
|
vgadev = list_first_entry_or_null(&vga_list, |
|
struct vga_device, list); |
|
if (vgadev) { |
|
struct device *dev = &vgadev->pdev->dev; |
|
vgaarb_info(dev, "setting as boot device (VGA legacy resources not available)\n"); |
|
vga_set_default_device(vgadev->pdev); |
|
} |
|
} |
|
} |
|
|
|
static int __init vga_arb_device_init(void) |
|
{ |
|
int rc; |
|
struct pci_dev *pdev; |
|
struct vga_device *vgadev; |
|
|
|
rc = misc_register(&vga_arb_device); |
|
if (rc < 0) |
|
pr_err("error %d registering device\n", rc); |
|
|
|
bus_register_notifier(&pci_bus_type, &pci_notifier); |
|
|
|
/* We add all PCI devices satisfying VGA class in the arbiter by |
|
* default */ |
|
pdev = NULL; |
|
while ((pdev = |
|
pci_get_subsys(PCI_ANY_ID, PCI_ANY_ID, PCI_ANY_ID, |
|
PCI_ANY_ID, pdev)) != NULL) |
|
vga_arbiter_add_pci_device(pdev); |
|
|
|
list_for_each_entry(vgadev, &vga_list, list) { |
|
struct device *dev = &vgadev->pdev->dev; |
|
|
|
if (vgadev->bridge_has_one_vga) |
|
vgaarb_info(dev, "bridge control possible\n"); |
|
else |
|
vgaarb_info(dev, "no bridge control possible\n"); |
|
} |
|
|
|
vga_arb_select_default_device(); |
|
|
|
pr_info("loaded\n"); |
|
return rc; |
|
} |
|
subsys_initcall(vga_arb_device_init);
|
|
|