mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-23 09:19:51 +00:00
![Tiago Vignatti](/assets/img/avatar_default.png)
Signed-off-by: Tiago Vignatti <tiago.vignatti@nokia.com> Cc: Henry Zhao <Henry.Zhao@Sun.COM> Signed-off-by: Dave Airlie <airlied@redhat.com>
1242 lines
32 KiB
C
1242 lines
32 KiB
C
/*
|
|
* vgaarb.c: Implements the VGA arbitration. For details refer to
|
|
* Documentation/vgaarbiter.txt
|
|
*
|
|
*
|
|
* (C) Copyright 2005 Benjamin Herrenschmidt <benh@kernel.crashing.org>
|
|
* (C) Copyright 2007 Paulo R. Zanoni <przanoni@gmail.com>
|
|
* (C) Copyright 2007, 2009 Tiago Vignatti <vignatti@freedesktop.org>
|
|
*
|
|
* Permission is hereby granted, free of charge, to any person obtaining a
|
|
* copy of this software and associated documentation files (the "Software"),
|
|
* to deal in the Software without restriction, including without limitation
|
|
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
|
|
* and/or sell copies of the Software, and to permit persons to whom the
|
|
* Software is furnished to do so, subject to the following conditions:
|
|
*
|
|
* The above copyright notice and this permission notice (including the next
|
|
* paragraph) shall be included in all copies or substantial portions of the
|
|
* Software.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
|
|
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
|
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
|
|
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
|
|
* DEALINGS
|
|
* IN THE SOFTWARE.
|
|
*
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/pci.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/init.h>
|
|
#include <linux/list.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/wait.h>
|
|
#include <linux/spinlock.h>
|
|
#include <linux/poll.h>
|
|
#include <linux/miscdevice.h>
|
|
#include <linux/slab.h>
|
|
|
|
#include <linux/uaccess.h>
|
|
|
|
#include <linux/vgaarb.h>
|
|
|
|
static void vga_arbiter_notify_clients(void);
|
|
/*
|
|
* We keep a list of all vga devices in the system to speed
|
|
* up the various operations of the arbiter
|
|
*/
|
|
struct vga_device {
|
|
struct list_head list;
|
|
struct pci_dev *pdev;
|
|
unsigned int decodes; /* what does it decodes */
|
|
unsigned int owns; /* what does it owns */
|
|
unsigned int locks; /* what does it locks */
|
|
unsigned int io_lock_cnt; /* legacy IO lock count */
|
|
unsigned int mem_lock_cnt; /* legacy MEM lock count */
|
|
unsigned int io_norm_cnt; /* normal IO count */
|
|
unsigned int mem_norm_cnt; /* normal MEM count */
|
|
|
|
/* allow IRQ enable/disable hook */
|
|
void *cookie;
|
|
void (*irq_set_state)(void *cookie, bool enable);
|
|
unsigned int (*set_vga_decode)(void *cookie, bool decode);
|
|
};
|
|
|
|
static LIST_HEAD(vga_list);
|
|
static int vga_count, vga_decode_count;
|
|
static bool vga_arbiter_used;
|
|
static DEFINE_SPINLOCK(vga_lock);
|
|
static DECLARE_WAIT_QUEUE_HEAD(vga_wait_queue);
|
|
|
|
|
|
static const char *vga_iostate_to_str(unsigned int iostate)
|
|
{
|
|
/* Ignore VGA_RSRC_IO and VGA_RSRC_MEM */
|
|
iostate &= VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM;
|
|
switch (iostate) {
|
|
case VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM:
|
|
return "io+mem";
|
|
case VGA_RSRC_LEGACY_IO:
|
|
return "io";
|
|
case VGA_RSRC_LEGACY_MEM:
|
|
return "mem";
|
|
}
|
|
return "none";
|
|
}
|
|
|
|
static int vga_str_to_iostate(char *buf, int str_size, int *io_state)
|
|
{
|
|
/* we could in theory hand out locks on IO and mem
|
|
* separately to userspace but it can cause deadlocks */
|
|
if (strncmp(buf, "none", 4) == 0) {
|
|
*io_state = VGA_RSRC_NONE;
|
|
return 1;
|
|
}
|
|
|
|
/* XXX We're not chekcing the str_size! */
|
|
if (strncmp(buf, "io+mem", 6) == 0)
|
|
goto both;
|
|
else if (strncmp(buf, "io", 2) == 0)
|
|
goto both;
|
|
else if (strncmp(buf, "mem", 3) == 0)
|
|
goto both;
|
|
return 0;
|
|
both:
|
|
*io_state = VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM;
|
|
return 1;
|
|
}
|
|
|
|
#ifndef __ARCH_HAS_VGA_DEFAULT_DEVICE
|
|
/* this is only used a cookie - it should not be dereferenced */
|
|
static struct pci_dev *vga_default;
|
|
#endif
|
|
|
|
static void vga_arb_device_card_gone(struct pci_dev *pdev);
|
|
|
|
/* Find somebody in our list */
|
|
static struct vga_device *vgadev_find(struct pci_dev *pdev)
|
|
{
|
|
struct vga_device *vgadev;
|
|
|
|
list_for_each_entry(vgadev, &vga_list, list)
|
|
if (pdev == vgadev->pdev)
|
|
return vgadev;
|
|
return NULL;
|
|
}
|
|
|
|
/* Returns the default VGA device (vgacon's babe) */
|
|
#ifndef __ARCH_HAS_VGA_DEFAULT_DEVICE
|
|
struct pci_dev *vga_default_device(void)
|
|
{
|
|
return vga_default;
|
|
}
|
|
#endif
|
|
|
|
static inline void vga_irq_set_state(struct vga_device *vgadev, bool state)
|
|
{
|
|
if (vgadev->irq_set_state)
|
|
vgadev->irq_set_state(vgadev->cookie, state);
|
|
}
|
|
|
|
|
|
/* If we don't ever use VGA arb we should avoid
|
|
turning off anything anywhere due to old X servers getting
|
|
confused about the boot device not being VGA */
|
|
static void vga_check_first_use(void)
|
|
{
|
|
/* we should inform all GPUs in the system that
|
|
* VGA arb has occured and to try and disable resources
|
|
* if they can */
|
|
if (!vga_arbiter_used) {
|
|
vga_arbiter_used = true;
|
|
vga_arbiter_notify_clients();
|
|
}
|
|
}
|
|
|
|
static struct vga_device *__vga_tryget(struct vga_device *vgadev,
|
|
unsigned int rsrc)
|
|
{
|
|
unsigned int wants, legacy_wants, match;
|
|
struct vga_device *conflict;
|
|
unsigned int pci_bits;
|
|
/* Account for "normal" resources to lock. If we decode the legacy,
|
|
* counterpart, we need to request it as well
|
|
*/
|
|
if ((rsrc & VGA_RSRC_NORMAL_IO) &&
|
|
(vgadev->decodes & VGA_RSRC_LEGACY_IO))
|
|
rsrc |= VGA_RSRC_LEGACY_IO;
|
|
if ((rsrc & VGA_RSRC_NORMAL_MEM) &&
|
|
(vgadev->decodes & VGA_RSRC_LEGACY_MEM))
|
|
rsrc |= VGA_RSRC_LEGACY_MEM;
|
|
|
|
pr_debug("%s: %d\n", __func__, rsrc);
|
|
pr_debug("%s: owns: %d\n", __func__, vgadev->owns);
|
|
|
|
/* Check what resources we need to acquire */
|
|
wants = rsrc & ~vgadev->owns;
|
|
|
|
/* We already own everything, just mark locked & bye bye */
|
|
if (wants == 0)
|
|
goto lock_them;
|
|
|
|
/* We don't need to request a legacy resource, we just enable
|
|
* appropriate decoding and go
|
|
*/
|
|
legacy_wants = wants & VGA_RSRC_LEGACY_MASK;
|
|
if (legacy_wants == 0)
|
|
goto enable_them;
|
|
|
|
/* Ok, we don't, let's find out how we need to kick off */
|
|
list_for_each_entry(conflict, &vga_list, list) {
|
|
unsigned int lwants = legacy_wants;
|
|
unsigned int change_bridge = 0;
|
|
|
|
/* Don't conflict with myself */
|
|
if (vgadev == conflict)
|
|
continue;
|
|
|
|
/* Check if the architecture allows a conflict between those
|
|
* 2 devices or if they are on separate domains
|
|
*/
|
|
if (!vga_conflicts(vgadev->pdev, conflict->pdev))
|
|
continue;
|
|
|
|
/* We have a possible conflict. before we go further, we must
|
|
* check if we sit on the same bus as the conflicting device.
|
|
* if we don't, then we must tie both IO and MEM resources
|
|
* together since there is only a single bit controlling
|
|
* VGA forwarding on P2P bridges
|
|
*/
|
|
if (vgadev->pdev->bus != conflict->pdev->bus) {
|
|
change_bridge = 1;
|
|
lwants = VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM;
|
|
}
|
|
|
|
/* Check if the guy has a lock on the resource. If he does,
|
|
* return the conflicting entry
|
|
*/
|
|
if (conflict->locks & lwants)
|
|
return conflict;
|
|
|
|
/* Ok, now check if he owns the resource we want. We don't need
|
|
* to check "decodes" since it should be impossible to own
|
|
* own legacy resources you don't decode unless I have a bug
|
|
* in this code...
|
|
*/
|
|
WARN_ON(conflict->owns & ~conflict->decodes);
|
|
match = lwants & conflict->owns;
|
|
if (!match)
|
|
continue;
|
|
|
|
/* looks like he doesn't have a lock, we can steal
|
|
* them from him
|
|
*/
|
|
vga_irq_set_state(conflict, false);
|
|
|
|
pci_bits = 0;
|
|
if (lwants & (VGA_RSRC_LEGACY_MEM|VGA_RSRC_NORMAL_MEM))
|
|
pci_bits |= PCI_COMMAND_MEMORY;
|
|
if (lwants & (VGA_RSRC_LEGACY_IO|VGA_RSRC_NORMAL_IO))
|
|
pci_bits |= PCI_COMMAND_IO;
|
|
|
|
pci_set_vga_state(conflict->pdev, false, pci_bits,
|
|
change_bridge);
|
|
conflict->owns &= ~lwants;
|
|
/* If he also owned non-legacy, that is no longer the case */
|
|
if (lwants & VGA_RSRC_LEGACY_MEM)
|
|
conflict->owns &= ~VGA_RSRC_NORMAL_MEM;
|
|
if (lwants & VGA_RSRC_LEGACY_IO)
|
|
conflict->owns &= ~VGA_RSRC_NORMAL_IO;
|
|
}
|
|
|
|
enable_them:
|
|
/* ok dude, we got it, everybody conflicting has been disabled, let's
|
|
* enable us. Make sure we don't mark a bit in "owns" that we don't
|
|
* also have in "decodes". We can lock resources we don't decode but
|
|
* not own them.
|
|
*/
|
|
pci_bits = 0;
|
|
if (wants & (VGA_RSRC_LEGACY_MEM|VGA_RSRC_NORMAL_MEM))
|
|
pci_bits |= PCI_COMMAND_MEMORY;
|
|
if (wants & (VGA_RSRC_LEGACY_IO|VGA_RSRC_NORMAL_IO))
|
|
pci_bits |= PCI_COMMAND_IO;
|
|
pci_set_vga_state(vgadev->pdev, true, pci_bits, !!(wants & VGA_RSRC_LEGACY_MASK));
|
|
|
|
vga_irq_set_state(vgadev, true);
|
|
vgadev->owns |= (wants & vgadev->decodes);
|
|
lock_them:
|
|
vgadev->locks |= (rsrc & VGA_RSRC_LEGACY_MASK);
|
|
if (rsrc & VGA_RSRC_LEGACY_IO)
|
|
vgadev->io_lock_cnt++;
|
|
if (rsrc & VGA_RSRC_LEGACY_MEM)
|
|
vgadev->mem_lock_cnt++;
|
|
if (rsrc & VGA_RSRC_NORMAL_IO)
|
|
vgadev->io_norm_cnt++;
|
|
if (rsrc & VGA_RSRC_NORMAL_MEM)
|
|
vgadev->mem_norm_cnt++;
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static void __vga_put(struct vga_device *vgadev, unsigned int rsrc)
|
|
{
|
|
unsigned int old_locks = vgadev->locks;
|
|
|
|
pr_debug("%s\n", __func__);
|
|
|
|
/* Update our counters, and account for equivalent legacy resources
|
|
* if we decode them
|
|
*/
|
|
if ((rsrc & VGA_RSRC_NORMAL_IO) && vgadev->io_norm_cnt > 0) {
|
|
vgadev->io_norm_cnt--;
|
|
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);
|
|
}
|
|
|
|
int vga_get(struct pci_dev *pdev, unsigned int rsrc, int interruptible)
|
|
{
|
|
struct vga_device *vgadev, *conflict;
|
|
unsigned long flags;
|
|
wait_queue_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 (signal_pending(current)) {
|
|
rc = -EINTR;
|
|
break;
|
|
}
|
|
schedule();
|
|
remove_wait_queue(&vga_wait_queue, &wait);
|
|
set_current_state(TASK_RUNNING);
|
|
}
|
|
return rc;
|
|
}
|
|
EXPORT_SYMBOL(vga_get);
|
|
|
|
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;
|
|
}
|
|
EXPORT_SYMBOL(vga_tryget);
|
|
|
|
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);
|
|
|
|
/*
|
|
* 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 = kmalloc(sizeof(struct vga_device), GFP_KERNEL);
|
|
if (vgadev == NULL) {
|
|
pr_err("vgaarb: failed to allocate pci device\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;
|
|
}
|
|
|
|
memset(vgadev, 0, sizeof(*vgadev));
|
|
|
|
/* 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
|
|
*/
|
|
#ifndef __ARCH_HAS_VGA_DEFAULT_DEVICE
|
|
if (vga_default == NULL &&
|
|
((vgadev->owns & VGA_RSRC_LEGACY_MASK) == VGA_RSRC_LEGACY_MASK))
|
|
vga_default = pci_dev_get(pdev);
|
|
#endif
|
|
|
|
/* Add to the list */
|
|
list_add(&vgadev->list, &vga_list);
|
|
vga_count++;
|
|
pr_info("vgaarb: device added: PCI:%s,decodes=%s,owns=%s,locks=%s\n",
|
|
pci_name(pdev),
|
|
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) {
|
|
pci_dev_put(vga_default);
|
|
vga_default = 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)
|
|
{
|
|
int old_decodes;
|
|
struct vga_device *new_vgadev, *conflict;
|
|
|
|
old_decodes = vgadev->decodes;
|
|
vgadev->decodes = new_decodes;
|
|
|
|
pr_info("vgaarb: device changed decodes: PCI:%s,olddecodes=%s,decodes=%s:owns=%s\n",
|
|
pci_name(vgadev->pdev),
|
|
vga_iostate_to_str(old_decodes),
|
|
vga_iostate_to_str(vgadev->decodes),
|
|
vga_iostate_to_str(vgadev->owns));
|
|
|
|
|
|
/* if we own the decodes we should move them along to
|
|
another card */
|
|
if ((vgadev->owns & old_decodes) && (vga_count > 1)) {
|
|
/* set us to own nothing */
|
|
vgadev->owns &= ~old_decodes;
|
|
list_for_each_entry(new_vgadev, &vga_list, list) {
|
|
if ((new_vgadev != vgadev) &&
|
|
(new_vgadev->decodes & VGA_RSRC_LEGACY_MASK)) {
|
|
pr_info("vgaarb: transferring owner from PCI:%s to PCI:%s\n", pci_name(vgadev->pdev), pci_name(new_vgadev->pdev));
|
|
conflict = __vga_tryget(new_vgadev, VGA_RSRC_LEGACY_MASK);
|
|
if (!conflict)
|
|
__vga_put(new_vgadev, VGA_RSRC_LEGACY_MASK);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* change decodes counter */
|
|
if (old_decodes != new_decodes) {
|
|
if (new_decodes & (VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM))
|
|
vga_decode_count++;
|
|
else
|
|
vga_decode_count--;
|
|
}
|
|
pr_debug("vgaarb: decoding count now is: %d\n", vga_decode_count);
|
|
}
|
|
|
|
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_vga_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);
|
|
}
|
|
|
|
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);
|
|
|
|
/* call with NULL to unregister */
|
|
int vga_client_register(struct pci_dev *pdev, void *cookie,
|
|
void (*irq_set_state)(void *cookie, bool state),
|
|
unsigned int (*set_vga_decode)(void *cookie, bool decode))
|
|
{
|
|
int ret = -1;
|
|
struct vga_device *vgadev;
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&vga_lock, flags);
|
|
vgadev = vgadev_find(pdev);
|
|
if (!vgadev)
|
|
goto bail;
|
|
|
|
vgadev->irq_set_state = irq_set_state;
|
|
vgadev->set_vga_decode = set_vga_decode;
|
|
vgadev->cookie = cookie;
|
|
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 targetting 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, *curr_pos;
|
|
size_t remaining = count;
|
|
|
|
int ret_val;
|
|
int i;
|
|
|
|
|
|
kbuf = kmalloc(count + 1, GFP_KERNEL);
|
|
if (!kbuf)
|
|
return -ENOMEM;
|
|
|
|
if (copy_from_user(kbuf, buf, count)) {
|
|
kfree(kbuf);
|
|
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)
|
|
return -EINVAL;
|
|
|
|
if (io_state & VGA_RSRC_LEGACY_IO && uc->io_cnt == 0)
|
|
return -EINVAL;
|
|
|
|
if (io_state & VGA_RSRC_LEGACY_MEM && uc->mem_cnt == 0)
|
|
return -EINVAL;
|
|
|
|
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) {
|
|
struct pci_bus *pbus;
|
|
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;
|
|
}
|
|
pr_debug("vgaarb: %s ==> %x:%x:%x.%x\n", curr_pos,
|
|
domain, bus, PCI_SLOT(devfn), PCI_FUNC(devfn));
|
|
|
|
pbus = pci_find_bus(domain, bus);
|
|
pr_debug("vgaarb: pbus %p\n", pbus);
|
|
if (pbus == NULL) {
|
|
pr_err("vgaarb: invalid PCI domain and/or bus address %x:%x\n",
|
|
domain, bus);
|
|
ret_val = -ENODEV;
|
|
goto done;
|
|
}
|
|
pdev = pci_get_slot(pbus, devfn);
|
|
pr_debug("vgaarb: pdev %p\n", pdev);
|
|
if (!pdev) {
|
|
pr_err("vgaarb: invalid PCI address %x:%x\n",
|
|
bus, devfn);
|
|
ret_val = -ENODEV;
|
|
goto done;
|
|
}
|
|
}
|
|
|
|
vgadev = vgadev_find(pdev);
|
|
pr_debug("vgaarb: vgadev %p\n", vgadev);
|
|
if (vgadev == NULL) {
|
|
pr_err("vgaarb: this pci device is 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) {
|
|
pr_err("vgaarb: maximum user cards (%d) number reached!\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("vgaarb: 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! */
|
|
kfree(kbuf);
|
|
return -EPROTO;
|
|
|
|
done:
|
|
kfree(kbuf);
|
|
return ret_val;
|
|
}
|
|
|
|
static unsigned int vga_arb_fpoll(struct file *file, poll_table * wait)
|
|
{
|
|
struct vga_arb_private *priv = file->private_data;
|
|
|
|
pr_debug("%s\n", __func__);
|
|
|
|
if (priv == NULL)
|
|
return -ENODEV;
|
|
poll_wait(file, &vga_wait_queue, wait);
|
|
return POLLIN;
|
|
}
|
|
|
|
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 = kmalloc(sizeof(struct vga_arb_private), GFP_KERNEL);
|
|
if (priv == NULL)
|
|
return -ENOMEM;
|
|
memset(priv, 0, sizeof(*priv));
|
|
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__);
|
|
|
|
if (priv == NULL)
|
|
return -ENODEV;
|
|
|
|
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;
|
|
pr_debug("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_vga_decode) {
|
|
new_decodes = vgadev->set_vga_decode(vgadev->cookie, 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;
|
|
|
|
pr_debug("%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,
|
|
};
|
|
|
|
static struct miscdevice vga_arb_device = {
|
|
MISC_DYNAMIC_MINOR, "vga_arbiter", &vga_arb_device_fops
|
|
};
|
|
|
|
static int __init vga_arb_device_init(void)
|
|
{
|
|
int rc;
|
|
struct pci_dev *pdev;
|
|
|
|
rc = misc_register(&vga_arb_device);
|
|
if (rc < 0)
|
|
pr_err("vgaarb: 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);
|
|
|
|
pr_info("vgaarb: loaded\n");
|
|
return rc;
|
|
}
|
|
subsys_initcall(vga_arb_device_init);
|