1f321c35fSBjorn Helgaas // SPDX-License-Identifier: MIT
21d38fe6eSBjorn Helgaas /*
3*cc64ca4bSSui Jingfeng * vgaarb.c: Implements VGA arbitration. For details refer to
41d38fe6eSBjorn Helgaas * Documentation/gpu/vgaarbiter.rst
51d38fe6eSBjorn Helgaas *
61d38fe6eSBjorn Helgaas * (C) Copyright 2005 Benjamin Herrenschmidt <benh@kernel.crashing.org>
71d38fe6eSBjorn Helgaas * (C) Copyright 2007 Paulo R. Zanoni <przanoni@gmail.com>
81d38fe6eSBjorn Helgaas * (C) Copyright 2007, 2009 Tiago Vignatti <vignatti@freedesktop.org>
91d38fe6eSBjorn Helgaas */
101d38fe6eSBjorn Helgaas
111d38fe6eSBjorn Helgaas #define pr_fmt(fmt) "vgaarb: " fmt
121d38fe6eSBjorn Helgaas
131d38fe6eSBjorn Helgaas #define vgaarb_dbg(dev, fmt, arg...) dev_dbg(dev, "vgaarb: " fmt, ##arg)
141d38fe6eSBjorn Helgaas #define vgaarb_info(dev, fmt, arg...) dev_info(dev, "vgaarb: " fmt, ##arg)
151d38fe6eSBjorn Helgaas #define vgaarb_err(dev, fmt, arg...) dev_err(dev, "vgaarb: " fmt, ##arg)
161d38fe6eSBjorn Helgaas
171d38fe6eSBjorn Helgaas #include <linux/module.h>
181d38fe6eSBjorn Helgaas #include <linux/kernel.h>
191d38fe6eSBjorn Helgaas #include <linux/pci.h>
201d38fe6eSBjorn Helgaas #include <linux/errno.h>
211d38fe6eSBjorn Helgaas #include <linux/init.h>
221d38fe6eSBjorn Helgaas #include <linux/list.h>
231d38fe6eSBjorn Helgaas #include <linux/sched/signal.h>
241d38fe6eSBjorn Helgaas #include <linux/wait.h>
251d38fe6eSBjorn Helgaas #include <linux/spinlock.h>
261d38fe6eSBjorn Helgaas #include <linux/poll.h>
271d38fe6eSBjorn Helgaas #include <linux/miscdevice.h>
281d38fe6eSBjorn Helgaas #include <linux/slab.h>
291d38fe6eSBjorn Helgaas #include <linux/screen_info.h>
301d38fe6eSBjorn Helgaas #include <linux/vt.h>
311d38fe6eSBjorn Helgaas #include <linux/console.h>
321d38fe6eSBjorn Helgaas #include <linux/acpi.h>
331d38fe6eSBjorn Helgaas #include <linux/uaccess.h>
341d38fe6eSBjorn Helgaas #include <linux/vgaarb.h>
351d38fe6eSBjorn Helgaas
361d38fe6eSBjorn Helgaas static void vga_arbiter_notify_clients(void);
37*cc64ca4bSSui Jingfeng
381d38fe6eSBjorn Helgaas /*
39*cc64ca4bSSui Jingfeng * We keep a list of all VGA devices in the system to speed
401d38fe6eSBjorn Helgaas * up the various operations of the arbiter
411d38fe6eSBjorn Helgaas */
421d38fe6eSBjorn Helgaas struct vga_device {
431d38fe6eSBjorn Helgaas struct list_head list;
441d38fe6eSBjorn Helgaas struct pci_dev *pdev;
45*cc64ca4bSSui Jingfeng unsigned int decodes; /* what it decodes */
46*cc64ca4bSSui Jingfeng unsigned int owns; /* what it owns */
47*cc64ca4bSSui Jingfeng unsigned int locks; /* what it locks */
481d38fe6eSBjorn Helgaas unsigned int io_lock_cnt; /* legacy IO lock count */
491d38fe6eSBjorn Helgaas unsigned int mem_lock_cnt; /* legacy MEM lock count */
501d38fe6eSBjorn Helgaas unsigned int io_norm_cnt; /* normal IO count */
511d38fe6eSBjorn Helgaas unsigned int mem_norm_cnt; /* normal MEM count */
521d38fe6eSBjorn Helgaas bool bridge_has_one_vga;
53f8d81df2SHuacai Chen bool is_firmware_default; /* device selected by firmware */
541d38fe6eSBjorn Helgaas unsigned int (*set_decode)(struct pci_dev *pdev, bool decode);
551d38fe6eSBjorn Helgaas };
561d38fe6eSBjorn Helgaas
571d38fe6eSBjorn Helgaas static LIST_HEAD(vga_list);
581d38fe6eSBjorn Helgaas static int vga_count, vga_decode_count;
591d38fe6eSBjorn Helgaas static bool vga_arbiter_used;
601d38fe6eSBjorn Helgaas static DEFINE_SPINLOCK(vga_lock);
611d38fe6eSBjorn Helgaas static DECLARE_WAIT_QUEUE_HEAD(vga_wait_queue);
621d38fe6eSBjorn Helgaas
vga_iostate_to_str(unsigned int iostate)631d38fe6eSBjorn Helgaas static const char *vga_iostate_to_str(unsigned int iostate)
641d38fe6eSBjorn Helgaas {
651d38fe6eSBjorn Helgaas /* Ignore VGA_RSRC_IO and VGA_RSRC_MEM */
661d38fe6eSBjorn Helgaas iostate &= VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM;
671d38fe6eSBjorn Helgaas switch (iostate) {
681d38fe6eSBjorn Helgaas case VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM:
691d38fe6eSBjorn Helgaas return "io+mem";
701d38fe6eSBjorn Helgaas case VGA_RSRC_LEGACY_IO:
711d38fe6eSBjorn Helgaas return "io";
721d38fe6eSBjorn Helgaas case VGA_RSRC_LEGACY_MEM:
731d38fe6eSBjorn Helgaas return "mem";
741d38fe6eSBjorn Helgaas }
751d38fe6eSBjorn Helgaas return "none";
761d38fe6eSBjorn Helgaas }
771d38fe6eSBjorn Helgaas
vga_str_to_iostate(char * buf,int str_size,unsigned int * io_state)7804c1c3c4SSui Jingfeng static int vga_str_to_iostate(char *buf, int str_size, unsigned int *io_state)
791d38fe6eSBjorn Helgaas {
80*cc64ca4bSSui Jingfeng /*
81*cc64ca4bSSui Jingfeng * In theory, we could hand out locks on IO and MEM separately to
82*cc64ca4bSSui Jingfeng * userspace, but this can cause deadlocks.
83*cc64ca4bSSui Jingfeng */
841d38fe6eSBjorn Helgaas if (strncmp(buf, "none", 4) == 0) {
851d38fe6eSBjorn Helgaas *io_state = VGA_RSRC_NONE;
861d38fe6eSBjorn Helgaas return 1;
871d38fe6eSBjorn Helgaas }
881d38fe6eSBjorn Helgaas
89*cc64ca4bSSui Jingfeng /* XXX We're not checking the str_size! */
901d38fe6eSBjorn Helgaas if (strncmp(buf, "io+mem", 6) == 0)
911d38fe6eSBjorn Helgaas goto both;
921d38fe6eSBjorn Helgaas else if (strncmp(buf, "io", 2) == 0)
931d38fe6eSBjorn Helgaas goto both;
941d38fe6eSBjorn Helgaas else if (strncmp(buf, "mem", 3) == 0)
951d38fe6eSBjorn Helgaas goto both;
961d38fe6eSBjorn Helgaas return 0;
971d38fe6eSBjorn Helgaas both:
981d38fe6eSBjorn Helgaas *io_state = VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM;
991d38fe6eSBjorn Helgaas return 1;
1001d38fe6eSBjorn Helgaas }
1011d38fe6eSBjorn Helgaas
102*cc64ca4bSSui Jingfeng /* This is only used as a cookie, it should not be dereferenced */
1031d38fe6eSBjorn Helgaas static struct pci_dev *vga_default;
1041d38fe6eSBjorn Helgaas
1051d38fe6eSBjorn Helgaas /* Find somebody in our list */
vgadev_find(struct pci_dev * pdev)1061d38fe6eSBjorn Helgaas static struct vga_device *vgadev_find(struct pci_dev *pdev)
1071d38fe6eSBjorn Helgaas {
1081d38fe6eSBjorn Helgaas struct vga_device *vgadev;
1091d38fe6eSBjorn Helgaas
1101d38fe6eSBjorn Helgaas list_for_each_entry(vgadev, &vga_list, list)
1111d38fe6eSBjorn Helgaas if (pdev == vgadev->pdev)
1121d38fe6eSBjorn Helgaas return vgadev;
1131d38fe6eSBjorn Helgaas return NULL;
1141d38fe6eSBjorn Helgaas }
1151d38fe6eSBjorn Helgaas
1161d38fe6eSBjorn Helgaas /**
1171d38fe6eSBjorn Helgaas * vga_default_device - return the default VGA device, for vgacon
1181d38fe6eSBjorn Helgaas *
119*cc64ca4bSSui Jingfeng * This can be defined by the platform. The default implementation is
120*cc64ca4bSSui Jingfeng * rather dumb and will probably only work properly on single VGA card
121*cc64ca4bSSui Jingfeng * setups and/or x86 platforms.
1221d38fe6eSBjorn Helgaas *
123*cc64ca4bSSui Jingfeng * If your VGA default device is not PCI, you'll have to return NULL here.
124*cc64ca4bSSui Jingfeng * In this case, I assume it will not conflict with any PCI card. If this
125*cc64ca4bSSui Jingfeng * is not true, I'll have to define two arch hooks for enabling/disabling
126*cc64ca4bSSui Jingfeng * the VGA default device if that is possible. This may be a problem with
127*cc64ca4bSSui Jingfeng * real _ISA_ VGA cards, in addition to a PCI one. I don't know at this
128*cc64ca4bSSui Jingfeng * point how to deal with that card. Can their IOs be disabled at all? If
129*cc64ca4bSSui Jingfeng * not, then I suppose it's a matter of having the proper arch hook telling
130*cc64ca4bSSui Jingfeng * us about it, so we basically never allow anybody to succeed a vga_get().
1311d38fe6eSBjorn Helgaas */
vga_default_device(void)1321d38fe6eSBjorn Helgaas struct pci_dev *vga_default_device(void)
1331d38fe6eSBjorn Helgaas {
1341d38fe6eSBjorn Helgaas return vga_default;
1351d38fe6eSBjorn Helgaas }
1361d38fe6eSBjorn Helgaas EXPORT_SYMBOL_GPL(vga_default_device);
1371d38fe6eSBjorn Helgaas
vga_set_default_device(struct pci_dev * pdev)1381d38fe6eSBjorn Helgaas void vga_set_default_device(struct pci_dev *pdev)
1391d38fe6eSBjorn Helgaas {
1401d38fe6eSBjorn Helgaas if (vga_default == pdev)
1411d38fe6eSBjorn Helgaas return;
1421d38fe6eSBjorn Helgaas
1431d38fe6eSBjorn Helgaas pci_dev_put(vga_default);
1441d38fe6eSBjorn Helgaas vga_default = pci_dev_get(pdev);
1451d38fe6eSBjorn Helgaas }
1461d38fe6eSBjorn Helgaas
1471d38fe6eSBjorn Helgaas /**
148*cc64ca4bSSui Jingfeng * vga_remove_vgacon - deactivate VGA console
1491d38fe6eSBjorn Helgaas *
150*cc64ca4bSSui Jingfeng * Unbind and unregister vgacon in case pdev is the default VGA device.
151*cc64ca4bSSui Jingfeng * Can be called by GPU drivers on initialization to make sure VGA register
152*cc64ca4bSSui Jingfeng * access done by vgacon will not disturb the device.
1531d38fe6eSBjorn Helgaas *
154*cc64ca4bSSui Jingfeng * @pdev: PCI device.
1551d38fe6eSBjorn Helgaas */
1561d38fe6eSBjorn Helgaas #if !defined(CONFIG_VGA_CONSOLE)
vga_remove_vgacon(struct pci_dev * pdev)1571d38fe6eSBjorn Helgaas int vga_remove_vgacon(struct pci_dev *pdev)
1581d38fe6eSBjorn Helgaas {
1591d38fe6eSBjorn Helgaas return 0;
1601d38fe6eSBjorn Helgaas }
1611d38fe6eSBjorn Helgaas #elif !defined(CONFIG_DUMMY_CONSOLE)
vga_remove_vgacon(struct pci_dev * pdev)1621d38fe6eSBjorn Helgaas int vga_remove_vgacon(struct pci_dev *pdev)
1631d38fe6eSBjorn Helgaas {
1641d38fe6eSBjorn Helgaas return -ENODEV;
1651d38fe6eSBjorn Helgaas }
1661d38fe6eSBjorn Helgaas #else
vga_remove_vgacon(struct pci_dev * pdev)1671d38fe6eSBjorn Helgaas int vga_remove_vgacon(struct pci_dev *pdev)
1681d38fe6eSBjorn Helgaas {
1691d38fe6eSBjorn Helgaas int ret = 0;
1701d38fe6eSBjorn Helgaas
1711d38fe6eSBjorn Helgaas if (pdev != vga_default)
1721d38fe6eSBjorn Helgaas return 0;
1731d38fe6eSBjorn Helgaas vgaarb_info(&pdev->dev, "deactivate vga console\n");
1741d38fe6eSBjorn Helgaas
1751d38fe6eSBjorn Helgaas console_lock();
1761d38fe6eSBjorn Helgaas if (con_is_bound(&vga_con))
1771d38fe6eSBjorn Helgaas ret = do_take_over_console(&dummy_con, 0,
1781d38fe6eSBjorn Helgaas MAX_NR_CONSOLES - 1, 1);
1791d38fe6eSBjorn Helgaas if (ret == 0) {
1801d38fe6eSBjorn Helgaas ret = do_unregister_con_driver(&vga_con);
1811d38fe6eSBjorn Helgaas
1821d38fe6eSBjorn Helgaas /* Ignore "already unregistered". */
1831d38fe6eSBjorn Helgaas if (ret == -ENODEV)
1841d38fe6eSBjorn Helgaas ret = 0;
1851d38fe6eSBjorn Helgaas }
1861d38fe6eSBjorn Helgaas console_unlock();
1871d38fe6eSBjorn Helgaas
1881d38fe6eSBjorn Helgaas return ret;
1891d38fe6eSBjorn Helgaas }
1901d38fe6eSBjorn Helgaas #endif
1911d38fe6eSBjorn Helgaas EXPORT_SYMBOL(vga_remove_vgacon);
1921d38fe6eSBjorn Helgaas
193*cc64ca4bSSui Jingfeng /*
194*cc64ca4bSSui Jingfeng * If we don't ever use VGA arbitration, we should avoid turning off
195*cc64ca4bSSui Jingfeng * anything anywhere due to old X servers getting confused about the boot
196*cc64ca4bSSui Jingfeng * device not being VGA.
197*cc64ca4bSSui Jingfeng */
vga_check_first_use(void)1981d38fe6eSBjorn Helgaas static void vga_check_first_use(void)
1991d38fe6eSBjorn Helgaas {
200*cc64ca4bSSui Jingfeng /*
201*cc64ca4bSSui Jingfeng * Inform all GPUs in the system that VGA arbitration has occurred
202*cc64ca4bSSui Jingfeng * so they can disable resources if possible.
203*cc64ca4bSSui Jingfeng */
2041d38fe6eSBjorn Helgaas if (!vga_arbiter_used) {
2051d38fe6eSBjorn Helgaas vga_arbiter_used = true;
2061d38fe6eSBjorn Helgaas vga_arbiter_notify_clients();
2071d38fe6eSBjorn Helgaas }
2081d38fe6eSBjorn Helgaas }
2091d38fe6eSBjorn Helgaas
__vga_tryget(struct vga_device * vgadev,unsigned int rsrc)2101d38fe6eSBjorn Helgaas static struct vga_device *__vga_tryget(struct vga_device *vgadev,
2111d38fe6eSBjorn Helgaas unsigned int rsrc)
2121d38fe6eSBjorn Helgaas {
2131d38fe6eSBjorn Helgaas struct device *dev = &vgadev->pdev->dev;
2141d38fe6eSBjorn Helgaas unsigned int wants, legacy_wants, match;
2151d38fe6eSBjorn Helgaas struct vga_device *conflict;
2161d38fe6eSBjorn Helgaas unsigned int pci_bits;
2171d38fe6eSBjorn Helgaas u32 flags = 0;
2181d38fe6eSBjorn Helgaas
219*cc64ca4bSSui Jingfeng /*
220*cc64ca4bSSui Jingfeng * Account for "normal" resources to lock. If we decode the legacy,
2211d38fe6eSBjorn Helgaas * counterpart, we need to request it as well
2221d38fe6eSBjorn Helgaas */
2231d38fe6eSBjorn Helgaas if ((rsrc & VGA_RSRC_NORMAL_IO) &&
2241d38fe6eSBjorn Helgaas (vgadev->decodes & VGA_RSRC_LEGACY_IO))
2251d38fe6eSBjorn Helgaas rsrc |= VGA_RSRC_LEGACY_IO;
2261d38fe6eSBjorn Helgaas if ((rsrc & VGA_RSRC_NORMAL_MEM) &&
2271d38fe6eSBjorn Helgaas (vgadev->decodes & VGA_RSRC_LEGACY_MEM))
2281d38fe6eSBjorn Helgaas rsrc |= VGA_RSRC_LEGACY_MEM;
2291d38fe6eSBjorn Helgaas
2301d38fe6eSBjorn Helgaas vgaarb_dbg(dev, "%s: %d\n", __func__, rsrc);
2311d38fe6eSBjorn Helgaas vgaarb_dbg(dev, "%s: owns: %d\n", __func__, vgadev->owns);
2321d38fe6eSBjorn Helgaas
2331d38fe6eSBjorn Helgaas /* Check what resources we need to acquire */
2341d38fe6eSBjorn Helgaas wants = rsrc & ~vgadev->owns;
2351d38fe6eSBjorn Helgaas
2361d38fe6eSBjorn Helgaas /* We already own everything, just mark locked & bye bye */
2371d38fe6eSBjorn Helgaas if (wants == 0)
2381d38fe6eSBjorn Helgaas goto lock_them;
2391d38fe6eSBjorn Helgaas
240*cc64ca4bSSui Jingfeng /*
241*cc64ca4bSSui Jingfeng * We don't need to request a legacy resource, we just enable
242*cc64ca4bSSui Jingfeng * appropriate decoding and go.
2431d38fe6eSBjorn Helgaas */
2441d38fe6eSBjorn Helgaas legacy_wants = wants & VGA_RSRC_LEGACY_MASK;
2451d38fe6eSBjorn Helgaas if (legacy_wants == 0)
2461d38fe6eSBjorn Helgaas goto enable_them;
2471d38fe6eSBjorn Helgaas
248*cc64ca4bSSui Jingfeng /* Ok, we don't, let's find out who we need to kick off */
2491d38fe6eSBjorn Helgaas list_for_each_entry(conflict, &vga_list, list) {
2501d38fe6eSBjorn Helgaas unsigned int lwants = legacy_wants;
2511d38fe6eSBjorn Helgaas unsigned int change_bridge = 0;
2521d38fe6eSBjorn Helgaas
2531d38fe6eSBjorn Helgaas /* Don't conflict with myself */
2541d38fe6eSBjorn Helgaas if (vgadev == conflict)
2551d38fe6eSBjorn Helgaas continue;
2561d38fe6eSBjorn Helgaas
257*cc64ca4bSSui Jingfeng /*
258*cc64ca4bSSui Jingfeng * We have a possible conflict. Before we go further, we must
2591d38fe6eSBjorn Helgaas * check if we sit on the same bus as the conflicting device.
260*cc64ca4bSSui Jingfeng * If we don't, then we must tie both IO and MEM resources
2611d38fe6eSBjorn Helgaas * together since there is only a single bit controlling
262*cc64ca4bSSui Jingfeng * VGA forwarding on P2P bridges.
2631d38fe6eSBjorn Helgaas */
2641d38fe6eSBjorn Helgaas if (vgadev->pdev->bus != conflict->pdev->bus) {
2651d38fe6eSBjorn Helgaas change_bridge = 1;
2661d38fe6eSBjorn Helgaas lwants = VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM;
2671d38fe6eSBjorn Helgaas }
2681d38fe6eSBjorn Helgaas
269*cc64ca4bSSui Jingfeng /*
270*cc64ca4bSSui Jingfeng * Check if the guy has a lock on the resource. If he does,
271*cc64ca4bSSui Jingfeng * return the conflicting entry.
2721d38fe6eSBjorn Helgaas */
2731d38fe6eSBjorn Helgaas if (conflict->locks & lwants)
2741d38fe6eSBjorn Helgaas return conflict;
2751d38fe6eSBjorn Helgaas
276*cc64ca4bSSui Jingfeng /*
277*cc64ca4bSSui Jingfeng * Ok, now check if it owns the resource we want. We can
278*cc64ca4bSSui Jingfeng * lock resources that are not decoded; therefore a device
2791d38fe6eSBjorn Helgaas * can own resources it doesn't decode.
2801d38fe6eSBjorn Helgaas */
2811d38fe6eSBjorn Helgaas match = lwants & conflict->owns;
2821d38fe6eSBjorn Helgaas if (!match)
2831d38fe6eSBjorn Helgaas continue;
2841d38fe6eSBjorn Helgaas
285*cc64ca4bSSui Jingfeng /*
286*cc64ca4bSSui Jingfeng * Looks like he doesn't have a lock, we can steal them
287*cc64ca4bSSui Jingfeng * from him.
2881d38fe6eSBjorn Helgaas */
2891d38fe6eSBjorn Helgaas
2901d38fe6eSBjorn Helgaas flags = 0;
2911d38fe6eSBjorn Helgaas pci_bits = 0;
2921d38fe6eSBjorn Helgaas
293*cc64ca4bSSui Jingfeng /*
294*cc64ca4bSSui Jingfeng * If we can't control legacy resources via the bridge, we
2951d38fe6eSBjorn Helgaas * also need to disable normal decoding.
2961d38fe6eSBjorn Helgaas */
2971d38fe6eSBjorn Helgaas if (!conflict->bridge_has_one_vga) {
2981d38fe6eSBjorn Helgaas if ((match & conflict->decodes) & VGA_RSRC_LEGACY_MEM)
2991d38fe6eSBjorn Helgaas pci_bits |= PCI_COMMAND_MEMORY;
3001d38fe6eSBjorn Helgaas if ((match & conflict->decodes) & VGA_RSRC_LEGACY_IO)
3011d38fe6eSBjorn Helgaas pci_bits |= PCI_COMMAND_IO;
3021d38fe6eSBjorn Helgaas
3031d38fe6eSBjorn Helgaas if (pci_bits)
3041d38fe6eSBjorn Helgaas flags |= PCI_VGA_STATE_CHANGE_DECODES;
3051d38fe6eSBjorn Helgaas }
3061d38fe6eSBjorn Helgaas
3071d38fe6eSBjorn Helgaas if (change_bridge)
3081d38fe6eSBjorn Helgaas flags |= PCI_VGA_STATE_CHANGE_BRIDGE;
3091d38fe6eSBjorn Helgaas
3101d38fe6eSBjorn Helgaas pci_set_vga_state(conflict->pdev, false, pci_bits, flags);
3111d38fe6eSBjorn Helgaas conflict->owns &= ~match;
3121d38fe6eSBjorn Helgaas
3131d38fe6eSBjorn Helgaas /* If we disabled normal decoding, reflect it in owns */
3141d38fe6eSBjorn Helgaas if (pci_bits & PCI_COMMAND_MEMORY)
3151d38fe6eSBjorn Helgaas conflict->owns &= ~VGA_RSRC_NORMAL_MEM;
3161d38fe6eSBjorn Helgaas if (pci_bits & PCI_COMMAND_IO)
3171d38fe6eSBjorn Helgaas conflict->owns &= ~VGA_RSRC_NORMAL_IO;
3181d38fe6eSBjorn Helgaas }
3191d38fe6eSBjorn Helgaas
3201d38fe6eSBjorn Helgaas enable_them:
321*cc64ca4bSSui Jingfeng /*
322*cc64ca4bSSui Jingfeng * Ok, we got it, everybody conflicting has been disabled, let's
3231d38fe6eSBjorn Helgaas * enable us. Mark any bits in "owns" regardless of whether we
3241d38fe6eSBjorn Helgaas * decoded them. We can lock resources we don't decode, therefore
3251d38fe6eSBjorn Helgaas * we must track them via "owns".
3261d38fe6eSBjorn Helgaas */
3271d38fe6eSBjorn Helgaas flags = 0;
3281d38fe6eSBjorn Helgaas pci_bits = 0;
3291d38fe6eSBjorn Helgaas
3301d38fe6eSBjorn Helgaas if (!vgadev->bridge_has_one_vga) {
3311d38fe6eSBjorn Helgaas flags |= PCI_VGA_STATE_CHANGE_DECODES;
3321d38fe6eSBjorn Helgaas if (wants & (VGA_RSRC_LEGACY_MEM|VGA_RSRC_NORMAL_MEM))
3331d38fe6eSBjorn Helgaas pci_bits |= PCI_COMMAND_MEMORY;
3341d38fe6eSBjorn Helgaas if (wants & (VGA_RSRC_LEGACY_IO|VGA_RSRC_NORMAL_IO))
3351d38fe6eSBjorn Helgaas pci_bits |= PCI_COMMAND_IO;
3361d38fe6eSBjorn Helgaas }
3371d38fe6eSBjorn Helgaas if (wants & VGA_RSRC_LEGACY_MASK)
3381d38fe6eSBjorn Helgaas flags |= PCI_VGA_STATE_CHANGE_BRIDGE;
3391d38fe6eSBjorn Helgaas
3401d38fe6eSBjorn Helgaas pci_set_vga_state(vgadev->pdev, true, pci_bits, flags);
3411d38fe6eSBjorn Helgaas
3421d38fe6eSBjorn Helgaas vgadev->owns |= wants;
3431d38fe6eSBjorn Helgaas lock_them:
3441d38fe6eSBjorn Helgaas vgadev->locks |= (rsrc & VGA_RSRC_LEGACY_MASK);
3451d38fe6eSBjorn Helgaas if (rsrc & VGA_RSRC_LEGACY_IO)
3461d38fe6eSBjorn Helgaas vgadev->io_lock_cnt++;
3471d38fe6eSBjorn Helgaas if (rsrc & VGA_RSRC_LEGACY_MEM)
3481d38fe6eSBjorn Helgaas vgadev->mem_lock_cnt++;
3491d38fe6eSBjorn Helgaas if (rsrc & VGA_RSRC_NORMAL_IO)
3501d38fe6eSBjorn Helgaas vgadev->io_norm_cnt++;
3511d38fe6eSBjorn Helgaas if (rsrc & VGA_RSRC_NORMAL_MEM)
3521d38fe6eSBjorn Helgaas vgadev->mem_norm_cnt++;
3531d38fe6eSBjorn Helgaas
3541d38fe6eSBjorn Helgaas return NULL;
3551d38fe6eSBjorn Helgaas }
3561d38fe6eSBjorn Helgaas
__vga_put(struct vga_device * vgadev,unsigned int rsrc)3571d38fe6eSBjorn Helgaas static void __vga_put(struct vga_device *vgadev, unsigned int rsrc)
3581d38fe6eSBjorn Helgaas {
3591d38fe6eSBjorn Helgaas struct device *dev = &vgadev->pdev->dev;
3601d38fe6eSBjorn Helgaas unsigned int old_locks = vgadev->locks;
3611d38fe6eSBjorn Helgaas
3621d38fe6eSBjorn Helgaas vgaarb_dbg(dev, "%s\n", __func__);
3631d38fe6eSBjorn Helgaas
364*cc64ca4bSSui Jingfeng /*
365*cc64ca4bSSui Jingfeng * Update our counters and account for equivalent legacy resources
366*cc64ca4bSSui Jingfeng * if we decode them.
3671d38fe6eSBjorn Helgaas */
3681d38fe6eSBjorn Helgaas if ((rsrc & VGA_RSRC_NORMAL_IO) && vgadev->io_norm_cnt > 0) {
3691d38fe6eSBjorn Helgaas vgadev->io_norm_cnt--;
3701d38fe6eSBjorn Helgaas if (vgadev->decodes & VGA_RSRC_LEGACY_IO)
3711d38fe6eSBjorn Helgaas rsrc |= VGA_RSRC_LEGACY_IO;
3721d38fe6eSBjorn Helgaas }
3731d38fe6eSBjorn Helgaas if ((rsrc & VGA_RSRC_NORMAL_MEM) && vgadev->mem_norm_cnt > 0) {
3741d38fe6eSBjorn Helgaas vgadev->mem_norm_cnt--;
3751d38fe6eSBjorn Helgaas if (vgadev->decodes & VGA_RSRC_LEGACY_MEM)
3761d38fe6eSBjorn Helgaas rsrc |= VGA_RSRC_LEGACY_MEM;
3771d38fe6eSBjorn Helgaas }
3781d38fe6eSBjorn Helgaas if ((rsrc & VGA_RSRC_LEGACY_IO) && vgadev->io_lock_cnt > 0)
3791d38fe6eSBjorn Helgaas vgadev->io_lock_cnt--;
3801d38fe6eSBjorn Helgaas if ((rsrc & VGA_RSRC_LEGACY_MEM) && vgadev->mem_lock_cnt > 0)
3811d38fe6eSBjorn Helgaas vgadev->mem_lock_cnt--;
3821d38fe6eSBjorn Helgaas
383*cc64ca4bSSui Jingfeng /*
384*cc64ca4bSSui Jingfeng * Just clear lock bits, we do lazy operations so we don't really
385*cc64ca4bSSui Jingfeng * have to bother about anything else at this point.
3861d38fe6eSBjorn Helgaas */
3871d38fe6eSBjorn Helgaas if (vgadev->io_lock_cnt == 0)
3881d38fe6eSBjorn Helgaas vgadev->locks &= ~VGA_RSRC_LEGACY_IO;
3891d38fe6eSBjorn Helgaas if (vgadev->mem_lock_cnt == 0)
3901d38fe6eSBjorn Helgaas vgadev->locks &= ~VGA_RSRC_LEGACY_MEM;
3911d38fe6eSBjorn Helgaas
392*cc64ca4bSSui Jingfeng /*
393*cc64ca4bSSui Jingfeng * Kick the wait queue in case somebody was waiting if we actually
394*cc64ca4bSSui Jingfeng * released something.
3951d38fe6eSBjorn Helgaas */
3961d38fe6eSBjorn Helgaas if (old_locks != vgadev->locks)
3971d38fe6eSBjorn Helgaas wake_up_all(&vga_wait_queue);
3981d38fe6eSBjorn Helgaas }
3991d38fe6eSBjorn Helgaas
4001d38fe6eSBjorn Helgaas /**
401*cc64ca4bSSui Jingfeng * vga_get - acquire & lock VGA resources
402*cc64ca4bSSui Jingfeng * @pdev: PCI device of the VGA card or NULL for the system default
4031d38fe6eSBjorn Helgaas * @rsrc: bit mask of resources to acquire and lock
4041d38fe6eSBjorn Helgaas * @interruptible: blocking should be interruptible by signals ?
4051d38fe6eSBjorn Helgaas *
406*cc64ca4bSSui Jingfeng * Acquire VGA resources for the given card and mark those resources
407*cc64ca4bSSui Jingfeng * locked. If the resources requested are "normal" (and not legacy)
4081d38fe6eSBjorn Helgaas * resources, the arbiter will first check whether the card is doing legacy
409*cc64ca4bSSui Jingfeng * decoding for that type of resource. If yes, the lock is "converted" into
410*cc64ca4bSSui Jingfeng * a legacy resource lock.
4111d38fe6eSBjorn Helgaas *
4121d38fe6eSBjorn Helgaas * The arbiter will first look for all VGA cards that might conflict and disable
4131d38fe6eSBjorn Helgaas * their IOs and/or Memory access, including VGA forwarding on P2P bridges if
4141d38fe6eSBjorn Helgaas * necessary, so that the requested resources can be used. Then, the card is
4151d38fe6eSBjorn Helgaas * marked as locking these resources and the IO and/or Memory accesses are
4161d38fe6eSBjorn Helgaas * enabled on the card (including VGA forwarding on parent P2P bridges if any).
4171d38fe6eSBjorn Helgaas *
4181d38fe6eSBjorn Helgaas * This function will block if some conflicting card is already locking one of
4191d38fe6eSBjorn Helgaas * the required resources (or any resource on a different bus segment, since P2P
4201d38fe6eSBjorn Helgaas * bridges don't differentiate VGA memory and IO afaik). You can indicate
4211d38fe6eSBjorn Helgaas * whether this blocking should be interruptible by a signal (for userland
4221d38fe6eSBjorn Helgaas * interface) or not.
4231d38fe6eSBjorn Helgaas *
4241d38fe6eSBjorn Helgaas * Must not be called at interrupt time or in atomic context. If the card
4251d38fe6eSBjorn Helgaas * already owns the resources, the function succeeds. Nested calls are
4261d38fe6eSBjorn Helgaas * supported (a per-resource counter is maintained)
4271d38fe6eSBjorn Helgaas *
4281d38fe6eSBjorn Helgaas * On success, release the VGA resource again with vga_put().
4291d38fe6eSBjorn Helgaas *
4301d38fe6eSBjorn Helgaas * Returns:
4311d38fe6eSBjorn Helgaas *
4321d38fe6eSBjorn Helgaas * 0 on success, negative error code on failure.
4331d38fe6eSBjorn Helgaas */
vga_get(struct pci_dev * pdev,unsigned int rsrc,int interruptible)4341d38fe6eSBjorn Helgaas int vga_get(struct pci_dev *pdev, unsigned int rsrc, int interruptible)
4351d38fe6eSBjorn Helgaas {
4361d38fe6eSBjorn Helgaas struct vga_device *vgadev, *conflict;
4371d38fe6eSBjorn Helgaas unsigned long flags;
4381d38fe6eSBjorn Helgaas wait_queue_entry_t wait;
4391d38fe6eSBjorn Helgaas int rc = 0;
4401d38fe6eSBjorn Helgaas
4411d38fe6eSBjorn Helgaas vga_check_first_use();
442*cc64ca4bSSui Jingfeng /* The caller should check for this, but let's be sure */
4431d38fe6eSBjorn Helgaas if (pdev == NULL)
4441d38fe6eSBjorn Helgaas pdev = vga_default_device();
4451d38fe6eSBjorn Helgaas if (pdev == NULL)
4461d38fe6eSBjorn Helgaas return 0;
4471d38fe6eSBjorn Helgaas
4481d38fe6eSBjorn Helgaas for (;;) {
4491d38fe6eSBjorn Helgaas spin_lock_irqsave(&vga_lock, flags);
4501d38fe6eSBjorn Helgaas vgadev = vgadev_find(pdev);
4511d38fe6eSBjorn Helgaas if (vgadev == NULL) {
4521d38fe6eSBjorn Helgaas spin_unlock_irqrestore(&vga_lock, flags);
4531d38fe6eSBjorn Helgaas rc = -ENODEV;
4541d38fe6eSBjorn Helgaas break;
4551d38fe6eSBjorn Helgaas }
4561d38fe6eSBjorn Helgaas conflict = __vga_tryget(vgadev, rsrc);
4571d38fe6eSBjorn Helgaas spin_unlock_irqrestore(&vga_lock, flags);
4581d38fe6eSBjorn Helgaas if (conflict == NULL)
4591d38fe6eSBjorn Helgaas break;
4601d38fe6eSBjorn Helgaas
461*cc64ca4bSSui Jingfeng /*
462*cc64ca4bSSui Jingfeng * We have a conflict; we wait until somebody kicks the
4631d38fe6eSBjorn Helgaas * work queue. Currently we have one work queue that we
4641d38fe6eSBjorn Helgaas * kick each time some resources are released, but it would
465*cc64ca4bSSui Jingfeng * be fairly easy to have a per-device one so that we only
466*cc64ca4bSSui Jingfeng * need to attach to the conflicting device.
4671d38fe6eSBjorn Helgaas */
4681d38fe6eSBjorn Helgaas init_waitqueue_entry(&wait, current);
4691d38fe6eSBjorn Helgaas add_wait_queue(&vga_wait_queue, &wait);
4701d38fe6eSBjorn Helgaas set_current_state(interruptible ?
4711d38fe6eSBjorn Helgaas TASK_INTERRUPTIBLE :
4721d38fe6eSBjorn Helgaas TASK_UNINTERRUPTIBLE);
4731d38fe6eSBjorn Helgaas if (interruptible && signal_pending(current)) {
4741d38fe6eSBjorn Helgaas __set_current_state(TASK_RUNNING);
4751d38fe6eSBjorn Helgaas remove_wait_queue(&vga_wait_queue, &wait);
4761d38fe6eSBjorn Helgaas rc = -ERESTARTSYS;
4771d38fe6eSBjorn Helgaas break;
4781d38fe6eSBjorn Helgaas }
4791d38fe6eSBjorn Helgaas schedule();
4801d38fe6eSBjorn Helgaas remove_wait_queue(&vga_wait_queue, &wait);
4811d38fe6eSBjorn Helgaas }
4821d38fe6eSBjorn Helgaas return rc;
4831d38fe6eSBjorn Helgaas }
4841d38fe6eSBjorn Helgaas EXPORT_SYMBOL(vga_get);
4851d38fe6eSBjorn Helgaas
4861d38fe6eSBjorn Helgaas /**
4871d38fe6eSBjorn Helgaas * vga_tryget - try to acquire & lock legacy VGA resources
488*cc64ca4bSSui Jingfeng * @pdev: PCI device of VGA card or NULL for system default
4891d38fe6eSBjorn Helgaas * @rsrc: bit mask of resources to acquire and lock
4901d38fe6eSBjorn Helgaas *
491*cc64ca4bSSui Jingfeng * Perform the same operation as vga_get(), but return an error (-EBUSY)
492*cc64ca4bSSui Jingfeng * instead of blocking if the resources are already locked by another card.
493*cc64ca4bSSui Jingfeng * Can be called in any context.
4941d38fe6eSBjorn Helgaas *
4951d38fe6eSBjorn Helgaas * On success, release the VGA resource again with vga_put().
4961d38fe6eSBjorn Helgaas *
4971d38fe6eSBjorn Helgaas * Returns:
4981d38fe6eSBjorn Helgaas *
4991d38fe6eSBjorn Helgaas * 0 on success, negative error code on failure.
5001d38fe6eSBjorn Helgaas */
vga_tryget(struct pci_dev * pdev,unsigned int rsrc)5011d38fe6eSBjorn Helgaas static int vga_tryget(struct pci_dev *pdev, unsigned int rsrc)
5021d38fe6eSBjorn Helgaas {
5031d38fe6eSBjorn Helgaas struct vga_device *vgadev;
5041d38fe6eSBjorn Helgaas unsigned long flags;
5051d38fe6eSBjorn Helgaas int rc = 0;
5061d38fe6eSBjorn Helgaas
5071d38fe6eSBjorn Helgaas vga_check_first_use();
5081d38fe6eSBjorn Helgaas
509*cc64ca4bSSui Jingfeng /* The caller should check for this, but let's be sure */
5101d38fe6eSBjorn Helgaas if (pdev == NULL)
5111d38fe6eSBjorn Helgaas pdev = vga_default_device();
5121d38fe6eSBjorn Helgaas if (pdev == NULL)
5131d38fe6eSBjorn Helgaas return 0;
5141d38fe6eSBjorn Helgaas spin_lock_irqsave(&vga_lock, flags);
5151d38fe6eSBjorn Helgaas vgadev = vgadev_find(pdev);
5161d38fe6eSBjorn Helgaas if (vgadev == NULL) {
5171d38fe6eSBjorn Helgaas rc = -ENODEV;
5181d38fe6eSBjorn Helgaas goto bail;
5191d38fe6eSBjorn Helgaas }
5201d38fe6eSBjorn Helgaas if (__vga_tryget(vgadev, rsrc))
5211d38fe6eSBjorn Helgaas rc = -EBUSY;
5221d38fe6eSBjorn Helgaas bail:
5231d38fe6eSBjorn Helgaas spin_unlock_irqrestore(&vga_lock, flags);
5241d38fe6eSBjorn Helgaas return rc;
5251d38fe6eSBjorn Helgaas }
5261d38fe6eSBjorn Helgaas
5271d38fe6eSBjorn Helgaas /**
5281d38fe6eSBjorn Helgaas * vga_put - release lock on legacy VGA resources
529*cc64ca4bSSui Jingfeng * @pdev: PCI device of VGA card or NULL for system default
530*cc64ca4bSSui Jingfeng * @rsrc: bit mask of resource to release
5311d38fe6eSBjorn Helgaas *
532*cc64ca4bSSui Jingfeng * Release resources previously locked by vga_get() or vga_tryget(). The
533*cc64ca4bSSui Jingfeng * resources aren't disabled right away, so that a subsequent vga_get() on
534*cc64ca4bSSui Jingfeng * the same card will succeed immediately. Resources have a counter, so
535*cc64ca4bSSui Jingfeng * locks are only released if the counter reaches 0.
5361d38fe6eSBjorn Helgaas */
vga_put(struct pci_dev * pdev,unsigned int rsrc)5371d38fe6eSBjorn Helgaas void vga_put(struct pci_dev *pdev, unsigned int rsrc)
5381d38fe6eSBjorn Helgaas {
5391d38fe6eSBjorn Helgaas struct vga_device *vgadev;
5401d38fe6eSBjorn Helgaas unsigned long flags;
5411d38fe6eSBjorn Helgaas
542*cc64ca4bSSui Jingfeng /* The caller should check for this, but let's be sure */
5431d38fe6eSBjorn Helgaas if (pdev == NULL)
5441d38fe6eSBjorn Helgaas pdev = vga_default_device();
5451d38fe6eSBjorn Helgaas if (pdev == NULL)
5461d38fe6eSBjorn Helgaas return;
5471d38fe6eSBjorn Helgaas spin_lock_irqsave(&vga_lock, flags);
5481d38fe6eSBjorn Helgaas vgadev = vgadev_find(pdev);
5491d38fe6eSBjorn Helgaas if (vgadev == NULL)
5501d38fe6eSBjorn Helgaas goto bail;
5511d38fe6eSBjorn Helgaas __vga_put(vgadev, rsrc);
5521d38fe6eSBjorn Helgaas bail:
5531d38fe6eSBjorn Helgaas spin_unlock_irqrestore(&vga_lock, flags);
5541d38fe6eSBjorn Helgaas }
5551d38fe6eSBjorn Helgaas EXPORT_SYMBOL(vga_put);
5561d38fe6eSBjorn Helgaas
vga_is_firmware_default(struct pci_dev * pdev)557f8d81df2SHuacai Chen static bool vga_is_firmware_default(struct pci_dev *pdev)
55860a9bac8SBjorn Helgaas {
55960a9bac8SBjorn Helgaas #if defined(CONFIG_X86) || defined(CONFIG_IA64)
56060a9bac8SBjorn Helgaas u64 base = screen_info.lfb_base;
56160a9bac8SBjorn Helgaas u64 size = screen_info.lfb_size;
56209cc9006SMika Westerberg struct resource *r;
56360a9bac8SBjorn Helgaas u64 limit;
56460a9bac8SBjorn Helgaas
56560a9bac8SBjorn Helgaas /* Select the device owning the boot framebuffer if there is one */
56660a9bac8SBjorn Helgaas
56760a9bac8SBjorn Helgaas if (screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE)
56860a9bac8SBjorn Helgaas base |= (u64)screen_info.ext_lfb_base << 32;
56960a9bac8SBjorn Helgaas
57060a9bac8SBjorn Helgaas limit = base + size;
57160a9bac8SBjorn Helgaas
57260a9bac8SBjorn Helgaas /* Does firmware framebuffer belong to us? */
57309cc9006SMika Westerberg pci_dev_for_each_resource(pdev, r) {
57409cc9006SMika Westerberg if (resource_type(r) != IORESOURCE_MEM)
57560a9bac8SBjorn Helgaas continue;
57660a9bac8SBjorn Helgaas
57709cc9006SMika Westerberg if (!r->start || !r->end)
57860a9bac8SBjorn Helgaas continue;
57960a9bac8SBjorn Helgaas
58009cc9006SMika Westerberg if (base < r->start || limit >= r->end)
58160a9bac8SBjorn Helgaas continue;
58260a9bac8SBjorn Helgaas
583f8d81df2SHuacai Chen return true;
58460a9bac8SBjorn Helgaas }
58560a9bac8SBjorn Helgaas #endif
586f8d81df2SHuacai Chen return false;
58760a9bac8SBjorn Helgaas }
58860a9bac8SBjorn Helgaas
vga_arb_integrated_gpu(struct device * dev)589c1593dddSHuacai Chen static bool vga_arb_integrated_gpu(struct device *dev)
590c1593dddSHuacai Chen {
591c1593dddSHuacai Chen #if defined(CONFIG_ACPI)
592c1593dddSHuacai Chen struct acpi_device *adev = ACPI_COMPANION(dev);
593c1593dddSHuacai Chen
594c1593dddSHuacai Chen return adev && !strcmp(acpi_device_hid(adev), ACPI_VIDEO_HID);
595c1593dddSHuacai Chen #else
596c1593dddSHuacai Chen return false;
597c1593dddSHuacai Chen #endif
598c1593dddSHuacai Chen }
599c1593dddSHuacai Chen
6001d38fe6eSBjorn Helgaas /*
601dfe3da81SHuacai Chen * Return true if vgadev is a better default VGA device than the best one
602dfe3da81SHuacai Chen * we've seen so far.
603dfe3da81SHuacai Chen */
vga_is_boot_device(struct vga_device * vgadev)604dfe3da81SHuacai Chen static bool vga_is_boot_device(struct vga_device *vgadev)
605dfe3da81SHuacai Chen {
606dfe3da81SHuacai Chen struct vga_device *boot_vga = vgadev_find(vga_default_device());
607f8d81df2SHuacai Chen struct pci_dev *pdev = vgadev->pdev;
608e96902ebSHuacai Chen u16 cmd, boot_cmd;
609dfe3da81SHuacai Chen
610dfe3da81SHuacai Chen /*
611dfe3da81SHuacai Chen * We select the default VGA device in this order:
612dfe3da81SHuacai Chen * Firmware framebuffer (see vga_arb_select_default_device())
613dfe3da81SHuacai Chen * Legacy VGA device (owns VGA_RSRC_LEGACY_MASK)
614dfe3da81SHuacai Chen * Non-legacy integrated device (see vga_arb_select_default_device())
615dfe3da81SHuacai Chen * Non-legacy discrete device (see vga_arb_select_default_device())
616dfe3da81SHuacai Chen * Other device (see vga_arb_select_default_device())
617dfe3da81SHuacai Chen */
618dfe3da81SHuacai Chen
619dfe3da81SHuacai Chen /*
620f8d81df2SHuacai Chen * We always prefer a firmware default device, so if we've already
621f8d81df2SHuacai Chen * found one, there's no need to consider vgadev.
622f8d81df2SHuacai Chen */
623f8d81df2SHuacai Chen if (boot_vga && boot_vga->is_firmware_default)
624f8d81df2SHuacai Chen return false;
625f8d81df2SHuacai Chen
626f8d81df2SHuacai Chen if (vga_is_firmware_default(pdev)) {
627f8d81df2SHuacai Chen vgadev->is_firmware_default = true;
628f8d81df2SHuacai Chen return true;
629f8d81df2SHuacai Chen }
630f8d81df2SHuacai Chen
631f8d81df2SHuacai Chen /*
632dfe3da81SHuacai Chen * A legacy VGA device has MEM and IO enabled and any bridges
633dfe3da81SHuacai Chen * leading to it have PCI_BRIDGE_CTL_VGA enabled so the legacy
634dfe3da81SHuacai Chen * resources ([mem 0xa0000-0xbffff], [io 0x3b0-0x3bb], etc) are
635dfe3da81SHuacai Chen * routed to it.
636dfe3da81SHuacai Chen *
637dfe3da81SHuacai Chen * We use the first one we find, so if we've already found one,
638dfe3da81SHuacai Chen * vgadev is no better.
639dfe3da81SHuacai Chen */
64037114e4dSHuacai Chen if (boot_vga &&
64137114e4dSHuacai Chen (boot_vga->owns & VGA_RSRC_LEGACY_MASK) == VGA_RSRC_LEGACY_MASK)
642dfe3da81SHuacai Chen return false;
643dfe3da81SHuacai Chen
644dfe3da81SHuacai Chen if ((vgadev->owns & VGA_RSRC_LEGACY_MASK) == VGA_RSRC_LEGACY_MASK)
645dfe3da81SHuacai Chen return true;
646dfe3da81SHuacai Chen
647e96902ebSHuacai Chen /*
648e96902ebSHuacai Chen * If we haven't found a legacy VGA device, accept a non-legacy
649e96902ebSHuacai Chen * device. It may have either IO or MEM enabled, and bridges may
650e96902ebSHuacai Chen * not have PCI_BRIDGE_CTL_VGA enabled, so it may not be able to
651e96902ebSHuacai Chen * use legacy VGA resources. Prefer an integrated GPU over others.
652e96902ebSHuacai Chen */
653e96902ebSHuacai Chen pci_read_config_word(pdev, PCI_COMMAND, &cmd);
654e96902ebSHuacai Chen if (cmd & (PCI_COMMAND_IO | PCI_COMMAND_MEMORY)) {
655e96902ebSHuacai Chen
656e96902ebSHuacai Chen /*
657e96902ebSHuacai Chen * An integrated GPU overrides a previous non-legacy
658e96902ebSHuacai Chen * device. We expect only a single integrated GPU, but if
659e96902ebSHuacai Chen * there are more, we use the *last* because that was the
660e96902ebSHuacai Chen * previous behavior.
661e96902ebSHuacai Chen */
662e96902ebSHuacai Chen if (vga_arb_integrated_gpu(&pdev->dev))
663e96902ebSHuacai Chen return true;
664e96902ebSHuacai Chen
665e96902ebSHuacai Chen /*
666e96902ebSHuacai Chen * We prefer the first non-legacy discrete device we find.
667e96902ebSHuacai Chen * If we already found one, vgadev is no better.
668e96902ebSHuacai Chen */
669e96902ebSHuacai Chen if (boot_vga) {
670e96902ebSHuacai Chen pci_read_config_word(boot_vga->pdev, PCI_COMMAND,
671e96902ebSHuacai Chen &boot_cmd);
672e96902ebSHuacai Chen if (boot_cmd & (PCI_COMMAND_IO | PCI_COMMAND_MEMORY))
673e96902ebSHuacai Chen return false;
674e96902ebSHuacai Chen }
675e96902ebSHuacai Chen return true;
676e96902ebSHuacai Chen }
677e96902ebSHuacai Chen
67837114e4dSHuacai Chen /*
679*cc64ca4bSSui Jingfeng * Vgadev has neither IO nor MEM enabled. If we haven't found any
68037114e4dSHuacai Chen * other VGA devices, it is the best candidate so far.
68137114e4dSHuacai Chen */
68237114e4dSHuacai Chen if (!boot_vga)
68337114e4dSHuacai Chen return true;
68437114e4dSHuacai Chen
685dfe3da81SHuacai Chen return false;
686dfe3da81SHuacai Chen }
687dfe3da81SHuacai Chen
688dfe3da81SHuacai Chen /*
6891d38fe6eSBjorn Helgaas * Rules for using a bridge to control a VGA descendant decoding: if a bridge
6901d38fe6eSBjorn Helgaas * has only one VGA descendant then it can be used to control the VGA routing
6911d38fe6eSBjorn Helgaas * for that device. It should always use the bridge closest to the device to
6921d38fe6eSBjorn Helgaas * control it. If a bridge has a direct VGA descendant, but also have a sub-
6931d38fe6eSBjorn Helgaas * bridge VGA descendant then we cannot use that bridge to control the direct
6941d38fe6eSBjorn Helgaas * VGA descendant. So for every device we register, we need to iterate all
6951d38fe6eSBjorn Helgaas * its parent bridges so we can invalidate any devices using them properly.
6961d38fe6eSBjorn Helgaas */
vga_arbiter_check_bridge_sharing(struct vga_device * vgadev)6971d38fe6eSBjorn Helgaas static void vga_arbiter_check_bridge_sharing(struct vga_device *vgadev)
6981d38fe6eSBjorn Helgaas {
6991d38fe6eSBjorn Helgaas struct vga_device *same_bridge_vgadev;
7001d38fe6eSBjorn Helgaas struct pci_bus *new_bus, *bus;
7011d38fe6eSBjorn Helgaas struct pci_dev *new_bridge, *bridge;
7021d38fe6eSBjorn Helgaas
7031d38fe6eSBjorn Helgaas vgadev->bridge_has_one_vga = true;
7041d38fe6eSBjorn Helgaas
7054e6c9184SHuacai Chen if (list_empty(&vga_list)) {
7064e6c9184SHuacai Chen vgaarb_info(&vgadev->pdev->dev, "bridge control possible\n");
7071d38fe6eSBjorn Helgaas return;
7084e6c9184SHuacai Chen }
7091d38fe6eSBjorn Helgaas
710*cc64ca4bSSui Jingfeng /* Iterate the new device's bridge hierarchy */
7111d38fe6eSBjorn Helgaas new_bus = vgadev->pdev->bus;
7121d38fe6eSBjorn Helgaas while (new_bus) {
7131d38fe6eSBjorn Helgaas new_bridge = new_bus->self;
7141d38fe6eSBjorn Helgaas
715*cc64ca4bSSui Jingfeng /* Go through list of devices already registered */
7161d38fe6eSBjorn Helgaas list_for_each_entry(same_bridge_vgadev, &vga_list, list) {
7171d38fe6eSBjorn Helgaas bus = same_bridge_vgadev->pdev->bus;
7181d38fe6eSBjorn Helgaas bridge = bus->self;
7191d38fe6eSBjorn Helgaas
720*cc64ca4bSSui Jingfeng /* See if it shares a bridge with this device */
7211d38fe6eSBjorn Helgaas if (new_bridge == bridge) {
7221d38fe6eSBjorn Helgaas /*
723*cc64ca4bSSui Jingfeng * If its direct parent bridge is the same
7241d38fe6eSBjorn Helgaas * as any bridge of this device then it can't
7251d38fe6eSBjorn Helgaas * be used for that device.
7261d38fe6eSBjorn Helgaas */
7271d38fe6eSBjorn Helgaas same_bridge_vgadev->bridge_has_one_vga = false;
7281d38fe6eSBjorn Helgaas }
7291d38fe6eSBjorn Helgaas
7301d38fe6eSBjorn Helgaas /*
731*cc64ca4bSSui Jingfeng * Now iterate the previous device's bridge hierarchy.
732*cc64ca4bSSui Jingfeng * If the new device's parent bridge is in the other
733*cc64ca4bSSui Jingfeng * device's hierarchy, we can't use it to control this
734*cc64ca4bSSui Jingfeng * device.
7351d38fe6eSBjorn Helgaas */
7361d38fe6eSBjorn Helgaas while (bus) {
7371d38fe6eSBjorn Helgaas bridge = bus->self;
7381d38fe6eSBjorn Helgaas
7391d38fe6eSBjorn Helgaas if (bridge && bridge == vgadev->pdev->bus->self)
7401d38fe6eSBjorn Helgaas vgadev->bridge_has_one_vga = false;
7411d38fe6eSBjorn Helgaas
7421d38fe6eSBjorn Helgaas bus = bus->parent;
7431d38fe6eSBjorn Helgaas }
7441d38fe6eSBjorn Helgaas }
7451d38fe6eSBjorn Helgaas new_bus = new_bus->parent;
7461d38fe6eSBjorn Helgaas }
7474e6c9184SHuacai Chen
7484e6c9184SHuacai Chen if (vgadev->bridge_has_one_vga)
7494e6c9184SHuacai Chen vgaarb_info(&vgadev->pdev->dev, "bridge control possible\n");
7504e6c9184SHuacai Chen else
7514e6c9184SHuacai Chen vgaarb_info(&vgadev->pdev->dev, "no bridge control possible\n");
7521d38fe6eSBjorn Helgaas }
7531d38fe6eSBjorn Helgaas
7541d38fe6eSBjorn Helgaas /*
755*cc64ca4bSSui Jingfeng * Currently, we assume that the "initial" setup of the system is not sane,
756*cc64ca4bSSui Jingfeng * that is, we come up with conflicting devices and let the arbiter's
757*cc64ca4bSSui Jingfeng * client decide if devices decodes legacy things or not.
7581d38fe6eSBjorn Helgaas */
vga_arbiter_add_pci_device(struct pci_dev * pdev)7591d38fe6eSBjorn Helgaas static bool vga_arbiter_add_pci_device(struct pci_dev *pdev)
7601d38fe6eSBjorn Helgaas {
7611d38fe6eSBjorn Helgaas struct vga_device *vgadev;
7621d38fe6eSBjorn Helgaas unsigned long flags;
7631d38fe6eSBjorn Helgaas struct pci_bus *bus;
7641d38fe6eSBjorn Helgaas struct pci_dev *bridge;
7651d38fe6eSBjorn Helgaas u16 cmd;
7661d38fe6eSBjorn Helgaas
7671d38fe6eSBjorn Helgaas /* Only deal with VGA class devices */
7681d38fe6eSBjorn Helgaas if ((pdev->class >> 8) != PCI_CLASS_DISPLAY_VGA)
7691d38fe6eSBjorn Helgaas return false;
7701d38fe6eSBjorn Helgaas
7711d38fe6eSBjorn Helgaas /* Allocate structure */
7721d38fe6eSBjorn Helgaas vgadev = kzalloc(sizeof(struct vga_device), GFP_KERNEL);
7731d38fe6eSBjorn Helgaas if (vgadev == NULL) {
7741d38fe6eSBjorn Helgaas vgaarb_err(&pdev->dev, "failed to allocate VGA arbiter data\n");
7751d38fe6eSBjorn Helgaas /*
7761d38fe6eSBjorn Helgaas * What to do on allocation failure? For now, let's just do
7771d38fe6eSBjorn Helgaas * nothing, I'm not sure there is anything saner to be done.
7781d38fe6eSBjorn Helgaas */
7791d38fe6eSBjorn Helgaas return false;
7801d38fe6eSBjorn Helgaas }
7811d38fe6eSBjorn Helgaas
7821d38fe6eSBjorn Helgaas /* Take lock & check for duplicates */
7831d38fe6eSBjorn Helgaas spin_lock_irqsave(&vga_lock, flags);
7841d38fe6eSBjorn Helgaas if (vgadev_find(pdev) != NULL) {
7851d38fe6eSBjorn Helgaas BUG_ON(1);
7861d38fe6eSBjorn Helgaas goto fail;
7871d38fe6eSBjorn Helgaas }
7881d38fe6eSBjorn Helgaas vgadev->pdev = pdev;
7891d38fe6eSBjorn Helgaas
7901d38fe6eSBjorn Helgaas /* By default, assume we decode everything */
7911d38fe6eSBjorn Helgaas vgadev->decodes = VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM |
7921d38fe6eSBjorn Helgaas VGA_RSRC_NORMAL_IO | VGA_RSRC_NORMAL_MEM;
7931d38fe6eSBjorn Helgaas
794*cc64ca4bSSui Jingfeng /* By default, mark it as decoding */
7951d38fe6eSBjorn Helgaas vga_decode_count++;
796*cc64ca4bSSui Jingfeng
797*cc64ca4bSSui Jingfeng /*
798*cc64ca4bSSui Jingfeng * Mark that we "own" resources based on our enables, we will
799*cc64ca4bSSui Jingfeng * clear that below if the bridge isn't forwarding.
8001d38fe6eSBjorn Helgaas */
8011d38fe6eSBjorn Helgaas pci_read_config_word(pdev, PCI_COMMAND, &cmd);
8021d38fe6eSBjorn Helgaas if (cmd & PCI_COMMAND_IO)
8031d38fe6eSBjorn Helgaas vgadev->owns |= VGA_RSRC_LEGACY_IO;
8041d38fe6eSBjorn Helgaas if (cmd & PCI_COMMAND_MEMORY)
8051d38fe6eSBjorn Helgaas vgadev->owns |= VGA_RSRC_LEGACY_MEM;
8061d38fe6eSBjorn Helgaas
8071d38fe6eSBjorn Helgaas /* Check if VGA cycles can get down to us */
8081d38fe6eSBjorn Helgaas bus = pdev->bus;
8091d38fe6eSBjorn Helgaas while (bus) {
8101d38fe6eSBjorn Helgaas bridge = bus->self;
8111d38fe6eSBjorn Helgaas if (bridge) {
8121d38fe6eSBjorn Helgaas u16 l;
8131d38fe6eSBjorn Helgaas
8141d38fe6eSBjorn Helgaas pci_read_config_word(bridge, PCI_BRIDGE_CONTROL, &l);
8151d38fe6eSBjorn Helgaas if (!(l & PCI_BRIDGE_CTL_VGA)) {
8161d38fe6eSBjorn Helgaas vgadev->owns = 0;
8171d38fe6eSBjorn Helgaas break;
8181d38fe6eSBjorn Helgaas }
8191d38fe6eSBjorn Helgaas }
8201d38fe6eSBjorn Helgaas bus = bus->parent;
8211d38fe6eSBjorn Helgaas }
8221d38fe6eSBjorn Helgaas
823dfe3da81SHuacai Chen if (vga_is_boot_device(vgadev)) {
824dfe3da81SHuacai Chen vgaarb_info(&pdev->dev, "setting as boot VGA device%s\n",
825dfe3da81SHuacai Chen vga_default_device() ?
826dfe3da81SHuacai Chen " (overriding previous)" : "");
8271d38fe6eSBjorn Helgaas vga_set_default_device(pdev);
8281d38fe6eSBjorn Helgaas }
8291d38fe6eSBjorn Helgaas
8301d38fe6eSBjorn Helgaas vga_arbiter_check_bridge_sharing(vgadev);
8311d38fe6eSBjorn Helgaas
8321d38fe6eSBjorn Helgaas /* Add to the list */
8331d38fe6eSBjorn Helgaas list_add_tail(&vgadev->list, &vga_list);
8341d38fe6eSBjorn Helgaas vga_count++;
8351d38fe6eSBjorn Helgaas vgaarb_info(&pdev->dev, "VGA device added: decodes=%s,owns=%s,locks=%s\n",
8361d38fe6eSBjorn Helgaas vga_iostate_to_str(vgadev->decodes),
8371d38fe6eSBjorn Helgaas vga_iostate_to_str(vgadev->owns),
8381d38fe6eSBjorn Helgaas vga_iostate_to_str(vgadev->locks));
8391d38fe6eSBjorn Helgaas
8401d38fe6eSBjorn Helgaas spin_unlock_irqrestore(&vga_lock, flags);
8411d38fe6eSBjorn Helgaas return true;
8421d38fe6eSBjorn Helgaas fail:
8431d38fe6eSBjorn Helgaas spin_unlock_irqrestore(&vga_lock, flags);
8441d38fe6eSBjorn Helgaas kfree(vgadev);
8451d38fe6eSBjorn Helgaas return false;
8461d38fe6eSBjorn Helgaas }
8471d38fe6eSBjorn Helgaas
vga_arbiter_del_pci_device(struct pci_dev * pdev)8481d38fe6eSBjorn Helgaas static bool vga_arbiter_del_pci_device(struct pci_dev *pdev)
8491d38fe6eSBjorn Helgaas {
8501d38fe6eSBjorn Helgaas struct vga_device *vgadev;
8511d38fe6eSBjorn Helgaas unsigned long flags;
8521d38fe6eSBjorn Helgaas bool ret = true;
8531d38fe6eSBjorn Helgaas
8541d38fe6eSBjorn Helgaas spin_lock_irqsave(&vga_lock, flags);
8551d38fe6eSBjorn Helgaas vgadev = vgadev_find(pdev);
8561d38fe6eSBjorn Helgaas if (vgadev == NULL) {
8571d38fe6eSBjorn Helgaas ret = false;
8581d38fe6eSBjorn Helgaas goto bail;
8591d38fe6eSBjorn Helgaas }
8601d38fe6eSBjorn Helgaas
8611d38fe6eSBjorn Helgaas if (vga_default == pdev)
8621d38fe6eSBjorn Helgaas vga_set_default_device(NULL);
8631d38fe6eSBjorn Helgaas
8641d38fe6eSBjorn Helgaas if (vgadev->decodes & (VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM))
8651d38fe6eSBjorn Helgaas vga_decode_count--;
8661d38fe6eSBjorn Helgaas
8671d38fe6eSBjorn Helgaas /* Remove entry from list */
8681d38fe6eSBjorn Helgaas list_del(&vgadev->list);
8691d38fe6eSBjorn Helgaas vga_count--;
8701d38fe6eSBjorn Helgaas
8711d38fe6eSBjorn Helgaas /* Wake up all possible waiters */
8721d38fe6eSBjorn Helgaas wake_up_all(&vga_wait_queue);
8731d38fe6eSBjorn Helgaas bail:
8741d38fe6eSBjorn Helgaas spin_unlock_irqrestore(&vga_lock, flags);
8751d38fe6eSBjorn Helgaas kfree(vgadev);
8761d38fe6eSBjorn Helgaas return ret;
8771d38fe6eSBjorn Helgaas }
8781d38fe6eSBjorn Helgaas
879*cc64ca4bSSui Jingfeng /* Called with the lock */
vga_update_device_decodes(struct vga_device * vgadev,unsigned int new_decodes)88060b4925dSSui Jingfeng static void vga_update_device_decodes(struct vga_device *vgadev,
88160b4925dSSui Jingfeng unsigned int new_decodes)
8821d38fe6eSBjorn Helgaas {
8831d38fe6eSBjorn Helgaas struct device *dev = &vgadev->pdev->dev;
88460b4925dSSui Jingfeng unsigned int old_decodes = vgadev->decodes;
88560b4925dSSui Jingfeng unsigned int decodes_removed = ~new_decodes & old_decodes;
88660b4925dSSui Jingfeng unsigned int decodes_unlocked = vgadev->locks & decodes_removed;
8871d38fe6eSBjorn Helgaas
8881d38fe6eSBjorn Helgaas vgadev->decodes = new_decodes;
8891d38fe6eSBjorn Helgaas
89060b4925dSSui Jingfeng vgaarb_info(dev, "VGA decodes changed: olddecodes=%s,decodes=%s:owns=%s\n",
8911d38fe6eSBjorn Helgaas vga_iostate_to_str(old_decodes),
8921d38fe6eSBjorn Helgaas vga_iostate_to_str(vgadev->decodes),
8931d38fe6eSBjorn Helgaas vga_iostate_to_str(vgadev->owns));
8941d38fe6eSBjorn Helgaas
89560b4925dSSui Jingfeng /* If we removed locked decodes, lock count goes to zero, and release */
8961d38fe6eSBjorn Helgaas if (decodes_unlocked) {
8971d38fe6eSBjorn Helgaas if (decodes_unlocked & VGA_RSRC_LEGACY_IO)
8981d38fe6eSBjorn Helgaas vgadev->io_lock_cnt = 0;
8991d38fe6eSBjorn Helgaas if (decodes_unlocked & VGA_RSRC_LEGACY_MEM)
9001d38fe6eSBjorn Helgaas vgadev->mem_lock_cnt = 0;
9011d38fe6eSBjorn Helgaas __vga_put(vgadev, decodes_unlocked);
9021d38fe6eSBjorn Helgaas }
9031d38fe6eSBjorn Helgaas
904*cc64ca4bSSui Jingfeng /* Change decodes counter */
9051d38fe6eSBjorn Helgaas if (old_decodes & VGA_RSRC_LEGACY_MASK &&
9061d38fe6eSBjorn Helgaas !(new_decodes & VGA_RSRC_LEGACY_MASK))
9071d38fe6eSBjorn Helgaas vga_decode_count--;
9081d38fe6eSBjorn Helgaas if (!(old_decodes & VGA_RSRC_LEGACY_MASK) &&
9091d38fe6eSBjorn Helgaas new_decodes & VGA_RSRC_LEGACY_MASK)
9101d38fe6eSBjorn Helgaas vga_decode_count++;
9111d38fe6eSBjorn Helgaas vgaarb_dbg(dev, "decoding count now is: %d\n", vga_decode_count);
9121d38fe6eSBjorn Helgaas }
9131d38fe6eSBjorn Helgaas
__vga_set_legacy_decoding(struct pci_dev * pdev,unsigned int decodes,bool userspace)9141d38fe6eSBjorn Helgaas static void __vga_set_legacy_decoding(struct pci_dev *pdev,
9151d38fe6eSBjorn Helgaas unsigned int decodes,
9161d38fe6eSBjorn Helgaas bool userspace)
9171d38fe6eSBjorn Helgaas {
9181d38fe6eSBjorn Helgaas struct vga_device *vgadev;
9191d38fe6eSBjorn Helgaas unsigned long flags;
9201d38fe6eSBjorn Helgaas
9211d38fe6eSBjorn Helgaas decodes &= VGA_RSRC_LEGACY_MASK;
9221d38fe6eSBjorn Helgaas
9231d38fe6eSBjorn Helgaas spin_lock_irqsave(&vga_lock, flags);
9241d38fe6eSBjorn Helgaas vgadev = vgadev_find(pdev);
9251d38fe6eSBjorn Helgaas if (vgadev == NULL)
9261d38fe6eSBjorn Helgaas goto bail;
9271d38fe6eSBjorn Helgaas
928*cc64ca4bSSui Jingfeng /* Don't let userspace futz with kernel driver decodes */
9291d38fe6eSBjorn Helgaas if (userspace && vgadev->set_decode)
9301d38fe6eSBjorn Helgaas goto bail;
9311d38fe6eSBjorn Helgaas
932*cc64ca4bSSui Jingfeng /* Update the device decodes + counter */
9331d38fe6eSBjorn Helgaas vga_update_device_decodes(vgadev, decodes);
9341d38fe6eSBjorn Helgaas
935*cc64ca4bSSui Jingfeng /*
936*cc64ca4bSSui Jingfeng * XXX If somebody is going from "doesn't decode" to "decodes"
937*cc64ca4bSSui Jingfeng * state here, additional care must be taken as we may have pending
938*cc64ca4bSSui Jingfeng * ownership of non-legacy region.
9391d38fe6eSBjorn Helgaas */
9401d38fe6eSBjorn Helgaas bail:
9411d38fe6eSBjorn Helgaas spin_unlock_irqrestore(&vga_lock, flags);
9421d38fe6eSBjorn Helgaas }
9431d38fe6eSBjorn Helgaas
9441d38fe6eSBjorn Helgaas /**
9451d38fe6eSBjorn Helgaas * vga_set_legacy_decoding
946*cc64ca4bSSui Jingfeng * @pdev: PCI device of the VGA card
9471d38fe6eSBjorn Helgaas * @decodes: bit mask of what legacy regions the card decodes
9481d38fe6eSBjorn Helgaas *
949*cc64ca4bSSui Jingfeng * Indicate to the arbiter if the card decodes legacy VGA IOs, legacy VGA
9501d38fe6eSBjorn Helgaas * Memory, both, or none. All cards default to both, the card driver (fbdev for
9511d38fe6eSBjorn Helgaas * example) should tell the arbiter if it has disabled legacy decoding, so the
9521d38fe6eSBjorn Helgaas * card can be left out of the arbitration process (and can be safe to take
9531d38fe6eSBjorn Helgaas * interrupts at any time.
9541d38fe6eSBjorn Helgaas */
vga_set_legacy_decoding(struct pci_dev * pdev,unsigned int decodes)9551d38fe6eSBjorn Helgaas void vga_set_legacy_decoding(struct pci_dev *pdev, unsigned int decodes)
9561d38fe6eSBjorn Helgaas {
9571d38fe6eSBjorn Helgaas __vga_set_legacy_decoding(pdev, decodes, false);
9581d38fe6eSBjorn Helgaas }
9591d38fe6eSBjorn Helgaas EXPORT_SYMBOL(vga_set_legacy_decoding);
9601d38fe6eSBjorn Helgaas
9611d38fe6eSBjorn Helgaas /**
9621d38fe6eSBjorn Helgaas * vga_client_register - register or unregister a VGA arbitration client
963*cc64ca4bSSui Jingfeng * @pdev: PCI device of the VGA client
964*cc64ca4bSSui Jingfeng * @set_decode: VGA decode change callback
9651d38fe6eSBjorn Helgaas *
9661d38fe6eSBjorn Helgaas * Clients have two callback mechanisms they can use.
9671d38fe6eSBjorn Helgaas *
9681d38fe6eSBjorn Helgaas * @set_decode callback: If a client can disable its GPU VGA resource, it
9691d38fe6eSBjorn Helgaas * will get a callback from this to set the encode/decode state.
9701d38fe6eSBjorn Helgaas *
971*cc64ca4bSSui Jingfeng * Rationale: we cannot disable VGA decode resources unconditionally
972*cc64ca4bSSui Jingfeng * because some single GPU laptops seem to require ACPI or BIOS access to
973*cc64ca4bSSui Jingfeng * the VGA registers to control things like backlights etc. Hopefully newer
974*cc64ca4bSSui Jingfeng * multi-GPU laptops do something saner, and desktops won't have any
975*cc64ca4bSSui Jingfeng * special ACPI for this. The driver will get a callback when VGA
976*cc64ca4bSSui Jingfeng * arbitration is first used by userspace since some older X servers have
977*cc64ca4bSSui Jingfeng * issues.
9781d38fe6eSBjorn Helgaas *
979*cc64ca4bSSui Jingfeng * Does not check whether a client for @pdev has been registered already.
9801d38fe6eSBjorn Helgaas *
981*cc64ca4bSSui Jingfeng * To unregister, call vga_client_unregister().
9821d38fe6eSBjorn Helgaas *
9834582db1dSSui Jingfeng * Returns: 0 on success, -ENODEV on failure
9841d38fe6eSBjorn Helgaas */
vga_client_register(struct pci_dev * pdev,unsigned int (* set_decode)(struct pci_dev * pdev,bool decode))9851d38fe6eSBjorn Helgaas int vga_client_register(struct pci_dev *pdev,
9861d38fe6eSBjorn Helgaas unsigned int (*set_decode)(struct pci_dev *pdev, bool decode))
9871d38fe6eSBjorn Helgaas {
9881d38fe6eSBjorn Helgaas unsigned long flags;
9894582db1dSSui Jingfeng struct vga_device *vgadev;
9901d38fe6eSBjorn Helgaas
9911d38fe6eSBjorn Helgaas spin_lock_irqsave(&vga_lock, flags);
9921d38fe6eSBjorn Helgaas vgadev = vgadev_find(pdev);
9934582db1dSSui Jingfeng if (vgadev)
9941d38fe6eSBjorn Helgaas vgadev->set_decode = set_decode;
9951d38fe6eSBjorn Helgaas spin_unlock_irqrestore(&vga_lock, flags);
9964582db1dSSui Jingfeng if (!vgadev)
9974582db1dSSui Jingfeng return -ENODEV;
9984582db1dSSui Jingfeng return 0;
9991d38fe6eSBjorn Helgaas }
10001d38fe6eSBjorn Helgaas EXPORT_SYMBOL(vga_client_register);
10011d38fe6eSBjorn Helgaas
10021d38fe6eSBjorn Helgaas /*
10031d38fe6eSBjorn Helgaas * Char driver implementation
10041d38fe6eSBjorn Helgaas *
10051d38fe6eSBjorn Helgaas * Semantics is:
10061d38fe6eSBjorn Helgaas *
1007*cc64ca4bSSui Jingfeng * open : Open user instance of the arbiter. By default, it's
10081d38fe6eSBjorn Helgaas * attached to the default VGA device of the system.
10091d38fe6eSBjorn Helgaas *
1010*cc64ca4bSSui Jingfeng * close : Close user instance, release locks
10111d38fe6eSBjorn Helgaas *
1012*cc64ca4bSSui Jingfeng * read : Return a string indicating the status of the target.
1013*cc64ca4bSSui Jingfeng * An IO state string is of the form {io,mem,io+mem,none},
10141d38fe6eSBjorn Helgaas * mc and ic are respectively mem and io lock counts (for
10151d38fe6eSBjorn Helgaas * debugging/diagnostic only). "decodes" indicate what the
10161d38fe6eSBjorn Helgaas * card currently decodes, "owns" indicates what is currently
10171d38fe6eSBjorn Helgaas * enabled on it, and "locks" indicates what is locked by this
10181d38fe6eSBjorn Helgaas * card. If the card is unplugged, we get "invalid" then for
10191d38fe6eSBjorn Helgaas * card_ID and an -ENODEV error is returned for any command
10201d38fe6eSBjorn Helgaas * until a new card is targeted
10211d38fe6eSBjorn Helgaas *
10221d38fe6eSBjorn Helgaas * "<card_ID>,decodes=<io_state>,owns=<io_state>,locks=<io_state> (ic,mc)"
10231d38fe6eSBjorn Helgaas *
10241d38fe6eSBjorn Helgaas * write : write a command to the arbiter. List of commands is:
10251d38fe6eSBjorn Helgaas *
10261d38fe6eSBjorn Helgaas * target <card_ID> : switch target to card <card_ID> (see below)
1027*cc64ca4bSSui Jingfeng * lock <io_state> : acquire locks on target ("none" is invalid io_state)
10281d38fe6eSBjorn Helgaas * trylock <io_state> : non-blocking acquire locks on target
10291d38fe6eSBjorn Helgaas * unlock <io_state> : release locks on target
10301d38fe6eSBjorn Helgaas * unlock all : release all locks on target held by this user
10311d38fe6eSBjorn Helgaas * decodes <io_state> : set the legacy decoding attributes for the card
10321d38fe6eSBjorn Helgaas *
10331d38fe6eSBjorn Helgaas * poll : event if something change on any card (not just the target)
10341d38fe6eSBjorn Helgaas *
10351d38fe6eSBjorn Helgaas * card_ID is of the form "PCI:domain:bus:dev.fn". It can be set to "default"
10361d38fe6eSBjorn Helgaas * to go back to the system default card (TODO: not implemented yet).
10371d38fe6eSBjorn Helgaas * Currently, only PCI is supported as a prefix, but the userland API may
10381d38fe6eSBjorn Helgaas * support other bus types in the future, even if the current kernel
10391d38fe6eSBjorn Helgaas * implementation doesn't.
10401d38fe6eSBjorn Helgaas *
10411d38fe6eSBjorn Helgaas * Note about locks:
10421d38fe6eSBjorn Helgaas *
10431d38fe6eSBjorn Helgaas * The driver keeps track of which user has what locks on which card. It
1044*cc64ca4bSSui Jingfeng * supports stacking, like the kernel one. This complicates the implementation
10451d38fe6eSBjorn Helgaas * a bit, but makes the arbiter more tolerant to userspace problems and able
10461d38fe6eSBjorn Helgaas * to properly cleanup in all cases when a process dies.
10471d38fe6eSBjorn Helgaas * Currently, a max of 16 cards simultaneously can have locks issued from
10481d38fe6eSBjorn Helgaas * userspace for a given user (file descriptor instance) of the arbiter.
10491d38fe6eSBjorn Helgaas *
10501d38fe6eSBjorn Helgaas * If the device is hot-unplugged, there is a hook inside the module to notify
1051*cc64ca4bSSui Jingfeng * it being added/removed in the system and automatically added/removed in
10521d38fe6eSBjorn Helgaas * the arbiter.
10531d38fe6eSBjorn Helgaas */
10541d38fe6eSBjorn Helgaas
10551d38fe6eSBjorn Helgaas #define MAX_USER_CARDS CONFIG_VGA_ARB_MAX_GPUS
10561d38fe6eSBjorn Helgaas #define PCI_INVALID_CARD ((struct pci_dev *)-1UL)
10571d38fe6eSBjorn Helgaas
1058*cc64ca4bSSui Jingfeng /* Each user has an array of these, tracking which cards have locks */
10591d38fe6eSBjorn Helgaas struct vga_arb_user_card {
10601d38fe6eSBjorn Helgaas struct pci_dev *pdev;
10611d38fe6eSBjorn Helgaas unsigned int mem_cnt;
10621d38fe6eSBjorn Helgaas unsigned int io_cnt;
10631d38fe6eSBjorn Helgaas };
10641d38fe6eSBjorn Helgaas
10651d38fe6eSBjorn Helgaas struct vga_arb_private {
10661d38fe6eSBjorn Helgaas struct list_head list;
10671d38fe6eSBjorn Helgaas struct pci_dev *target;
10681d38fe6eSBjorn Helgaas struct vga_arb_user_card cards[MAX_USER_CARDS];
10691d38fe6eSBjorn Helgaas spinlock_t lock;
10701d38fe6eSBjorn Helgaas };
10711d38fe6eSBjorn Helgaas
10721d38fe6eSBjorn Helgaas static LIST_HEAD(vga_user_list);
10731d38fe6eSBjorn Helgaas static DEFINE_SPINLOCK(vga_user_lock);
10741d38fe6eSBjorn Helgaas
10751d38fe6eSBjorn Helgaas
10761d38fe6eSBjorn Helgaas /*
1077*cc64ca4bSSui Jingfeng * Take a string in the format: "PCI:domain:bus:dev.fn" and return the
1078*cc64ca4bSSui Jingfeng * respective values. If the string is not in this format, return 0.
10791d38fe6eSBjorn Helgaas */
vga_pci_str_to_vars(char * buf,int count,unsigned int * domain,unsigned int * bus,unsigned int * devfn)10801d38fe6eSBjorn Helgaas static int vga_pci_str_to_vars(char *buf, int count, unsigned int *domain,
10811d38fe6eSBjorn Helgaas unsigned int *bus, unsigned int *devfn)
10821d38fe6eSBjorn Helgaas {
10831d38fe6eSBjorn Helgaas int n;
10841d38fe6eSBjorn Helgaas unsigned int slot, func;
10851d38fe6eSBjorn Helgaas
10861d38fe6eSBjorn Helgaas n = sscanf(buf, "PCI:%x:%x:%x.%x", domain, bus, &slot, &func);
10871d38fe6eSBjorn Helgaas if (n != 4)
10881d38fe6eSBjorn Helgaas return 0;
10891d38fe6eSBjorn Helgaas
10901d38fe6eSBjorn Helgaas *devfn = PCI_DEVFN(slot, func);
10911d38fe6eSBjorn Helgaas
10921d38fe6eSBjorn Helgaas return 1;
10931d38fe6eSBjorn Helgaas }
10941d38fe6eSBjorn Helgaas
vga_arb_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)10951d38fe6eSBjorn Helgaas static ssize_t vga_arb_read(struct file *file, char __user *buf,
10961d38fe6eSBjorn Helgaas size_t count, loff_t *ppos)
10971d38fe6eSBjorn Helgaas {
10981d38fe6eSBjorn Helgaas struct vga_arb_private *priv = file->private_data;
10991d38fe6eSBjorn Helgaas struct vga_device *vgadev;
11001d38fe6eSBjorn Helgaas struct pci_dev *pdev;
11011d38fe6eSBjorn Helgaas unsigned long flags;
11021d38fe6eSBjorn Helgaas size_t len;
11031d38fe6eSBjorn Helgaas int rc;
11041d38fe6eSBjorn Helgaas char *lbuf;
11051d38fe6eSBjorn Helgaas
11061d38fe6eSBjorn Helgaas lbuf = kmalloc(1024, GFP_KERNEL);
11071d38fe6eSBjorn Helgaas if (lbuf == NULL)
11081d38fe6eSBjorn Helgaas return -ENOMEM;
11091d38fe6eSBjorn Helgaas
1110*cc64ca4bSSui Jingfeng /* Protect vga_list */
11111d38fe6eSBjorn Helgaas spin_lock_irqsave(&vga_lock, flags);
11121d38fe6eSBjorn Helgaas
11131d38fe6eSBjorn Helgaas /* If we are targeting the default, use it */
11141d38fe6eSBjorn Helgaas pdev = priv->target;
11151d38fe6eSBjorn Helgaas if (pdev == NULL || pdev == PCI_INVALID_CARD) {
11161d38fe6eSBjorn Helgaas spin_unlock_irqrestore(&vga_lock, flags);
11171d38fe6eSBjorn Helgaas len = sprintf(lbuf, "invalid");
11181d38fe6eSBjorn Helgaas goto done;
11191d38fe6eSBjorn Helgaas }
11201d38fe6eSBjorn Helgaas
11211d38fe6eSBjorn Helgaas /* Find card vgadev structure */
11221d38fe6eSBjorn Helgaas vgadev = vgadev_find(pdev);
11231d38fe6eSBjorn Helgaas if (vgadev == NULL) {
1124*cc64ca4bSSui Jingfeng /*
1125*cc64ca4bSSui Jingfeng * Wow, it's not in the list, that shouldn't happen, let's
1126*cc64ca4bSSui Jingfeng * fix us up and return invalid card.
11271d38fe6eSBjorn Helgaas */
11281d38fe6eSBjorn Helgaas spin_unlock_irqrestore(&vga_lock, flags);
11291d38fe6eSBjorn Helgaas len = sprintf(lbuf, "invalid");
11301d38fe6eSBjorn Helgaas goto done;
11311d38fe6eSBjorn Helgaas }
11321d38fe6eSBjorn Helgaas
1133*cc64ca4bSSui Jingfeng /* Fill the buffer with info */
11341d38fe6eSBjorn Helgaas len = snprintf(lbuf, 1024,
1135d5109fe4SBjorn Helgaas "count:%d,PCI:%s,decodes=%s,owns=%s,locks=%s(%u:%u)\n",
11361d38fe6eSBjorn Helgaas vga_decode_count, pci_name(pdev),
11371d38fe6eSBjorn Helgaas vga_iostate_to_str(vgadev->decodes),
11381d38fe6eSBjorn Helgaas vga_iostate_to_str(vgadev->owns),
11391d38fe6eSBjorn Helgaas vga_iostate_to_str(vgadev->locks),
11401d38fe6eSBjorn Helgaas vgadev->io_lock_cnt, vgadev->mem_lock_cnt);
11411d38fe6eSBjorn Helgaas
11421d38fe6eSBjorn Helgaas spin_unlock_irqrestore(&vga_lock, flags);
11431d38fe6eSBjorn Helgaas done:
11441d38fe6eSBjorn Helgaas
11451d38fe6eSBjorn Helgaas /* Copy that to user */
11461d38fe6eSBjorn Helgaas if (len > count)
11471d38fe6eSBjorn Helgaas len = count;
11481d38fe6eSBjorn Helgaas rc = copy_to_user(buf, lbuf, len);
11491d38fe6eSBjorn Helgaas kfree(lbuf);
11501d38fe6eSBjorn Helgaas if (rc)
11511d38fe6eSBjorn Helgaas return -EFAULT;
11521d38fe6eSBjorn Helgaas return len;
11531d38fe6eSBjorn Helgaas }
11541d38fe6eSBjorn Helgaas
11551d38fe6eSBjorn Helgaas /*
11561d38fe6eSBjorn Helgaas * TODO: To avoid parsing inside kernel and to improve the speed we may
11571d38fe6eSBjorn Helgaas * consider use ioctl here
11581d38fe6eSBjorn Helgaas */
vga_arb_write(struct file * file,const char __user * buf,size_t count,loff_t * ppos)11591d38fe6eSBjorn Helgaas static ssize_t vga_arb_write(struct file *file, const char __user *buf,
11601d38fe6eSBjorn Helgaas size_t count, loff_t *ppos)
11611d38fe6eSBjorn Helgaas {
11621d38fe6eSBjorn Helgaas struct vga_arb_private *priv = file->private_data;
11631d38fe6eSBjorn Helgaas struct vga_arb_user_card *uc = NULL;
11641d38fe6eSBjorn Helgaas struct pci_dev *pdev;
11651d38fe6eSBjorn Helgaas
11661d38fe6eSBjorn Helgaas unsigned int io_state;
11671d38fe6eSBjorn Helgaas
11681d38fe6eSBjorn Helgaas char kbuf[64], *curr_pos;
11691d38fe6eSBjorn Helgaas size_t remaining = count;
11701d38fe6eSBjorn Helgaas
11711d38fe6eSBjorn Helgaas int ret_val;
11721d38fe6eSBjorn Helgaas int i;
11731d38fe6eSBjorn Helgaas
11741d38fe6eSBjorn Helgaas if (count >= sizeof(kbuf))
11751d38fe6eSBjorn Helgaas return -EINVAL;
11761d38fe6eSBjorn Helgaas if (copy_from_user(kbuf, buf, count))
11771d38fe6eSBjorn Helgaas return -EFAULT;
11781d38fe6eSBjorn Helgaas curr_pos = kbuf;
1179*cc64ca4bSSui Jingfeng kbuf[count] = '\0';
11801d38fe6eSBjorn Helgaas
11811d38fe6eSBjorn Helgaas if (strncmp(curr_pos, "lock ", 5) == 0) {
11821d38fe6eSBjorn Helgaas curr_pos += 5;
11831d38fe6eSBjorn Helgaas remaining -= 5;
11841d38fe6eSBjorn Helgaas
11851d38fe6eSBjorn Helgaas pr_debug("client 0x%p called 'lock'\n", priv);
11861d38fe6eSBjorn Helgaas
11871d38fe6eSBjorn Helgaas if (!vga_str_to_iostate(curr_pos, remaining, &io_state)) {
11881d38fe6eSBjorn Helgaas ret_val = -EPROTO;
11891d38fe6eSBjorn Helgaas goto done;
11901d38fe6eSBjorn Helgaas }
11911d38fe6eSBjorn Helgaas if (io_state == VGA_RSRC_NONE) {
11921d38fe6eSBjorn Helgaas ret_val = -EPROTO;
11931d38fe6eSBjorn Helgaas goto done;
11941d38fe6eSBjorn Helgaas }
11951d38fe6eSBjorn Helgaas
11961d38fe6eSBjorn Helgaas pdev = priv->target;
11971d38fe6eSBjorn Helgaas if (priv->target == NULL) {
11981d38fe6eSBjorn Helgaas ret_val = -ENODEV;
11991d38fe6eSBjorn Helgaas goto done;
12001d38fe6eSBjorn Helgaas }
12011d38fe6eSBjorn Helgaas
12021d38fe6eSBjorn Helgaas vga_get_uninterruptible(pdev, io_state);
12031d38fe6eSBjorn Helgaas
1204*cc64ca4bSSui Jingfeng /* Update the client's locks lists */
12051d38fe6eSBjorn Helgaas for (i = 0; i < MAX_USER_CARDS; i++) {
12061d38fe6eSBjorn Helgaas if (priv->cards[i].pdev == pdev) {
12071d38fe6eSBjorn Helgaas if (io_state & VGA_RSRC_LEGACY_IO)
12081d38fe6eSBjorn Helgaas priv->cards[i].io_cnt++;
12091d38fe6eSBjorn Helgaas if (io_state & VGA_RSRC_LEGACY_MEM)
12101d38fe6eSBjorn Helgaas priv->cards[i].mem_cnt++;
12111d38fe6eSBjorn Helgaas break;
12121d38fe6eSBjorn Helgaas }
12131d38fe6eSBjorn Helgaas }
12141d38fe6eSBjorn Helgaas
12151d38fe6eSBjorn Helgaas ret_val = count;
12161d38fe6eSBjorn Helgaas goto done;
12171d38fe6eSBjorn Helgaas } else if (strncmp(curr_pos, "unlock ", 7) == 0) {
12181d38fe6eSBjorn Helgaas curr_pos += 7;
12191d38fe6eSBjorn Helgaas remaining -= 7;
12201d38fe6eSBjorn Helgaas
12211d38fe6eSBjorn Helgaas pr_debug("client 0x%p called 'unlock'\n", priv);
12221d38fe6eSBjorn Helgaas
12231d38fe6eSBjorn Helgaas if (strncmp(curr_pos, "all", 3) == 0)
12241d38fe6eSBjorn Helgaas io_state = VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM;
12251d38fe6eSBjorn Helgaas else {
12261d38fe6eSBjorn Helgaas if (!vga_str_to_iostate
12271d38fe6eSBjorn Helgaas (curr_pos, remaining, &io_state)) {
12281d38fe6eSBjorn Helgaas ret_val = -EPROTO;
12291d38fe6eSBjorn Helgaas goto done;
12301d38fe6eSBjorn Helgaas }
12311d38fe6eSBjorn Helgaas /* TODO: Add this?
12321d38fe6eSBjorn Helgaas if (io_state == VGA_RSRC_NONE) {
12331d38fe6eSBjorn Helgaas ret_val = -EPROTO;
12341d38fe6eSBjorn Helgaas goto done;
12351d38fe6eSBjorn Helgaas }
12361d38fe6eSBjorn Helgaas */
12371d38fe6eSBjorn Helgaas }
12381d38fe6eSBjorn Helgaas
12391d38fe6eSBjorn Helgaas pdev = priv->target;
12401d38fe6eSBjorn Helgaas if (priv->target == NULL) {
12411d38fe6eSBjorn Helgaas ret_val = -ENODEV;
12421d38fe6eSBjorn Helgaas goto done;
12431d38fe6eSBjorn Helgaas }
12441d38fe6eSBjorn Helgaas for (i = 0; i < MAX_USER_CARDS; i++) {
12451d38fe6eSBjorn Helgaas if (priv->cards[i].pdev == pdev)
12461d38fe6eSBjorn Helgaas uc = &priv->cards[i];
12471d38fe6eSBjorn Helgaas }
12481d38fe6eSBjorn Helgaas
12491d38fe6eSBjorn Helgaas if (!uc) {
12501d38fe6eSBjorn Helgaas ret_val = -EINVAL;
12511d38fe6eSBjorn Helgaas goto done;
12521d38fe6eSBjorn Helgaas }
12531d38fe6eSBjorn Helgaas
12541d38fe6eSBjorn Helgaas if (io_state & VGA_RSRC_LEGACY_IO && uc->io_cnt == 0) {
12551d38fe6eSBjorn Helgaas ret_val = -EINVAL;
12561d38fe6eSBjorn Helgaas goto done;
12571d38fe6eSBjorn Helgaas }
12581d38fe6eSBjorn Helgaas
12591d38fe6eSBjorn Helgaas if (io_state & VGA_RSRC_LEGACY_MEM && uc->mem_cnt == 0) {
12601d38fe6eSBjorn Helgaas ret_val = -EINVAL;
12611d38fe6eSBjorn Helgaas goto done;
12621d38fe6eSBjorn Helgaas }
12631d38fe6eSBjorn Helgaas
12641d38fe6eSBjorn Helgaas vga_put(pdev, io_state);
12651d38fe6eSBjorn Helgaas
12661d38fe6eSBjorn Helgaas if (io_state & VGA_RSRC_LEGACY_IO)
12671d38fe6eSBjorn Helgaas uc->io_cnt--;
12681d38fe6eSBjorn Helgaas if (io_state & VGA_RSRC_LEGACY_MEM)
12691d38fe6eSBjorn Helgaas uc->mem_cnt--;
12701d38fe6eSBjorn Helgaas
12711d38fe6eSBjorn Helgaas ret_val = count;
12721d38fe6eSBjorn Helgaas goto done;
12731d38fe6eSBjorn Helgaas } else if (strncmp(curr_pos, "trylock ", 8) == 0) {
12741d38fe6eSBjorn Helgaas curr_pos += 8;
12751d38fe6eSBjorn Helgaas remaining -= 8;
12761d38fe6eSBjorn Helgaas
12771d38fe6eSBjorn Helgaas pr_debug("client 0x%p called 'trylock'\n", priv);
12781d38fe6eSBjorn Helgaas
12791d38fe6eSBjorn Helgaas if (!vga_str_to_iostate(curr_pos, remaining, &io_state)) {
12801d38fe6eSBjorn Helgaas ret_val = -EPROTO;
12811d38fe6eSBjorn Helgaas goto done;
12821d38fe6eSBjorn Helgaas }
12831d38fe6eSBjorn Helgaas /* TODO: Add this?
12841d38fe6eSBjorn Helgaas if (io_state == VGA_RSRC_NONE) {
12851d38fe6eSBjorn Helgaas ret_val = -EPROTO;
12861d38fe6eSBjorn Helgaas goto done;
12871d38fe6eSBjorn Helgaas }
12881d38fe6eSBjorn Helgaas */
12891d38fe6eSBjorn Helgaas
12901d38fe6eSBjorn Helgaas pdev = priv->target;
12911d38fe6eSBjorn Helgaas if (priv->target == NULL) {
12921d38fe6eSBjorn Helgaas ret_val = -ENODEV;
12931d38fe6eSBjorn Helgaas goto done;
12941d38fe6eSBjorn Helgaas }
12951d38fe6eSBjorn Helgaas
12961d38fe6eSBjorn Helgaas if (vga_tryget(pdev, io_state)) {
12971d38fe6eSBjorn Helgaas /* Update the client's locks lists... */
12981d38fe6eSBjorn Helgaas for (i = 0; i < MAX_USER_CARDS; i++) {
12991d38fe6eSBjorn Helgaas if (priv->cards[i].pdev == pdev) {
13001d38fe6eSBjorn Helgaas if (io_state & VGA_RSRC_LEGACY_IO)
13011d38fe6eSBjorn Helgaas priv->cards[i].io_cnt++;
13021d38fe6eSBjorn Helgaas if (io_state & VGA_RSRC_LEGACY_MEM)
13031d38fe6eSBjorn Helgaas priv->cards[i].mem_cnt++;
13041d38fe6eSBjorn Helgaas break;
13051d38fe6eSBjorn Helgaas }
13061d38fe6eSBjorn Helgaas }
13071d38fe6eSBjorn Helgaas ret_val = count;
13081d38fe6eSBjorn Helgaas goto done;
13091d38fe6eSBjorn Helgaas } else {
13101d38fe6eSBjorn Helgaas ret_val = -EBUSY;
13111d38fe6eSBjorn Helgaas goto done;
13121d38fe6eSBjorn Helgaas }
13131d38fe6eSBjorn Helgaas
13141d38fe6eSBjorn Helgaas } else if (strncmp(curr_pos, "target ", 7) == 0) {
13151d38fe6eSBjorn Helgaas unsigned int domain, bus, devfn;
13161d38fe6eSBjorn Helgaas struct vga_device *vgadev;
13171d38fe6eSBjorn Helgaas
13181d38fe6eSBjorn Helgaas curr_pos += 7;
13191d38fe6eSBjorn Helgaas remaining -= 7;
13201d38fe6eSBjorn Helgaas pr_debug("client 0x%p called 'target'\n", priv);
1321*cc64ca4bSSui Jingfeng /* If target is default */
13221d38fe6eSBjorn Helgaas if (!strncmp(curr_pos, "default", 7))
13231d38fe6eSBjorn Helgaas pdev = pci_dev_get(vga_default_device());
13241d38fe6eSBjorn Helgaas else {
13251d38fe6eSBjorn Helgaas if (!vga_pci_str_to_vars(curr_pos, remaining,
13261d38fe6eSBjorn Helgaas &domain, &bus, &devfn)) {
13271d38fe6eSBjorn Helgaas ret_val = -EPROTO;
13281d38fe6eSBjorn Helgaas goto done;
13291d38fe6eSBjorn Helgaas }
13301d38fe6eSBjorn Helgaas pdev = pci_get_domain_bus_and_slot(domain, bus, devfn);
13311d38fe6eSBjorn Helgaas if (!pdev) {
13321d38fe6eSBjorn Helgaas pr_debug("invalid PCI address %04x:%02x:%02x.%x\n",
13331d38fe6eSBjorn Helgaas domain, bus, PCI_SLOT(devfn),
13341d38fe6eSBjorn Helgaas PCI_FUNC(devfn));
13351d38fe6eSBjorn Helgaas ret_val = -ENODEV;
13361d38fe6eSBjorn Helgaas goto done;
13371d38fe6eSBjorn Helgaas }
13381d38fe6eSBjorn Helgaas
13391d38fe6eSBjorn Helgaas pr_debug("%s ==> %04x:%02x:%02x.%x pdev %p\n", curr_pos,
13401d38fe6eSBjorn Helgaas domain, bus, PCI_SLOT(devfn), PCI_FUNC(devfn),
13411d38fe6eSBjorn Helgaas pdev);
13421d38fe6eSBjorn Helgaas }
13431d38fe6eSBjorn Helgaas
13441d38fe6eSBjorn Helgaas vgadev = vgadev_find(pdev);
13451d38fe6eSBjorn Helgaas pr_debug("vgadev %p\n", vgadev);
13461d38fe6eSBjorn Helgaas if (vgadev == NULL) {
13471d38fe6eSBjorn Helgaas if (pdev) {
13481d38fe6eSBjorn Helgaas vgaarb_dbg(&pdev->dev, "not a VGA device\n");
13491d38fe6eSBjorn Helgaas pci_dev_put(pdev);
13501d38fe6eSBjorn Helgaas }
13511d38fe6eSBjorn Helgaas
13521d38fe6eSBjorn Helgaas ret_val = -ENODEV;
13531d38fe6eSBjorn Helgaas goto done;
13541d38fe6eSBjorn Helgaas }
13551d38fe6eSBjorn Helgaas
13561d38fe6eSBjorn Helgaas priv->target = pdev;
13571d38fe6eSBjorn Helgaas for (i = 0; i < MAX_USER_CARDS; i++) {
13581d38fe6eSBjorn Helgaas if (priv->cards[i].pdev == pdev)
13591d38fe6eSBjorn Helgaas break;
13601d38fe6eSBjorn Helgaas if (priv->cards[i].pdev == NULL) {
13611d38fe6eSBjorn Helgaas priv->cards[i].pdev = pdev;
13621d38fe6eSBjorn Helgaas priv->cards[i].io_cnt = 0;
13631d38fe6eSBjorn Helgaas priv->cards[i].mem_cnt = 0;
13641d38fe6eSBjorn Helgaas break;
13651d38fe6eSBjorn Helgaas }
13661d38fe6eSBjorn Helgaas }
13671d38fe6eSBjorn Helgaas if (i == MAX_USER_CARDS) {
13681d38fe6eSBjorn Helgaas vgaarb_dbg(&pdev->dev, "maximum user cards (%d) number reached, ignoring this one!\n",
13691d38fe6eSBjorn Helgaas MAX_USER_CARDS);
13701d38fe6eSBjorn Helgaas pci_dev_put(pdev);
1371*cc64ca4bSSui Jingfeng /* XXX: Which value to return? */
13721d38fe6eSBjorn Helgaas ret_val = -ENOMEM;
13731d38fe6eSBjorn Helgaas goto done;
13741d38fe6eSBjorn Helgaas }
13751d38fe6eSBjorn Helgaas
13761d38fe6eSBjorn Helgaas ret_val = count;
13771d38fe6eSBjorn Helgaas pci_dev_put(pdev);
13781d38fe6eSBjorn Helgaas goto done;
13791d38fe6eSBjorn Helgaas
13801d38fe6eSBjorn Helgaas
13811d38fe6eSBjorn Helgaas } else if (strncmp(curr_pos, "decodes ", 8) == 0) {
13821d38fe6eSBjorn Helgaas curr_pos += 8;
13831d38fe6eSBjorn Helgaas remaining -= 8;
13841d38fe6eSBjorn Helgaas pr_debug("client 0x%p called 'decodes'\n", priv);
13851d38fe6eSBjorn Helgaas
13861d38fe6eSBjorn Helgaas if (!vga_str_to_iostate(curr_pos, remaining, &io_state)) {
13871d38fe6eSBjorn Helgaas ret_val = -EPROTO;
13881d38fe6eSBjorn Helgaas goto done;
13891d38fe6eSBjorn Helgaas }
13901d38fe6eSBjorn Helgaas pdev = priv->target;
13911d38fe6eSBjorn Helgaas if (priv->target == NULL) {
13921d38fe6eSBjorn Helgaas ret_val = -ENODEV;
13931d38fe6eSBjorn Helgaas goto done;
13941d38fe6eSBjorn Helgaas }
13951d38fe6eSBjorn Helgaas
13961d38fe6eSBjorn Helgaas __vga_set_legacy_decoding(pdev, io_state, true);
13971d38fe6eSBjorn Helgaas ret_val = count;
13981d38fe6eSBjorn Helgaas goto done;
13991d38fe6eSBjorn Helgaas }
14001d38fe6eSBjorn Helgaas /* If we got here, the message written is not part of the protocol! */
14011d38fe6eSBjorn Helgaas return -EPROTO;
14021d38fe6eSBjorn Helgaas
14031d38fe6eSBjorn Helgaas done:
14041d38fe6eSBjorn Helgaas return ret_val;
14051d38fe6eSBjorn Helgaas }
14061d38fe6eSBjorn Helgaas
vga_arb_fpoll(struct file * file,poll_table * wait)14071d38fe6eSBjorn Helgaas static __poll_t vga_arb_fpoll(struct file *file, poll_table *wait)
14081d38fe6eSBjorn Helgaas {
14091d38fe6eSBjorn Helgaas pr_debug("%s\n", __func__);
14101d38fe6eSBjorn Helgaas
14111d38fe6eSBjorn Helgaas poll_wait(file, &vga_wait_queue, wait);
14121d38fe6eSBjorn Helgaas return EPOLLIN;
14131d38fe6eSBjorn Helgaas }
14141d38fe6eSBjorn Helgaas
vga_arb_open(struct inode * inode,struct file * file)14151d38fe6eSBjorn Helgaas static int vga_arb_open(struct inode *inode, struct file *file)
14161d38fe6eSBjorn Helgaas {
14171d38fe6eSBjorn Helgaas struct vga_arb_private *priv;
14181d38fe6eSBjorn Helgaas unsigned long flags;
14191d38fe6eSBjorn Helgaas
14201d38fe6eSBjorn Helgaas pr_debug("%s\n", __func__);
14211d38fe6eSBjorn Helgaas
14221d38fe6eSBjorn Helgaas priv = kzalloc(sizeof(*priv), GFP_KERNEL);
14231d38fe6eSBjorn Helgaas if (priv == NULL)
14241d38fe6eSBjorn Helgaas return -ENOMEM;
14251d38fe6eSBjorn Helgaas spin_lock_init(&priv->lock);
14261d38fe6eSBjorn Helgaas file->private_data = priv;
14271d38fe6eSBjorn Helgaas
14281d38fe6eSBjorn Helgaas spin_lock_irqsave(&vga_user_lock, flags);
14291d38fe6eSBjorn Helgaas list_add(&priv->list, &vga_user_list);
14301d38fe6eSBjorn Helgaas spin_unlock_irqrestore(&vga_user_lock, flags);
14311d38fe6eSBjorn Helgaas
1432*cc64ca4bSSui Jingfeng /* Set the client's lists of locks */
14331d38fe6eSBjorn Helgaas priv->target = vga_default_device(); /* Maybe this is still null! */
14341d38fe6eSBjorn Helgaas priv->cards[0].pdev = priv->target;
14351d38fe6eSBjorn Helgaas priv->cards[0].io_cnt = 0;
14361d38fe6eSBjorn Helgaas priv->cards[0].mem_cnt = 0;
14371d38fe6eSBjorn Helgaas
14381d38fe6eSBjorn Helgaas return 0;
14391d38fe6eSBjorn Helgaas }
14401d38fe6eSBjorn Helgaas
vga_arb_release(struct inode * inode,struct file * file)14411d38fe6eSBjorn Helgaas static int vga_arb_release(struct inode *inode, struct file *file)
14421d38fe6eSBjorn Helgaas {
14431d38fe6eSBjorn Helgaas struct vga_arb_private *priv = file->private_data;
14441d38fe6eSBjorn Helgaas struct vga_arb_user_card *uc;
14451d38fe6eSBjorn Helgaas unsigned long flags;
14461d38fe6eSBjorn Helgaas int i;
14471d38fe6eSBjorn Helgaas
14481d38fe6eSBjorn Helgaas pr_debug("%s\n", __func__);
14491d38fe6eSBjorn Helgaas
14501d38fe6eSBjorn Helgaas spin_lock_irqsave(&vga_user_lock, flags);
14511d38fe6eSBjorn Helgaas list_del(&priv->list);
14521d38fe6eSBjorn Helgaas for (i = 0; i < MAX_USER_CARDS; i++) {
14531d38fe6eSBjorn Helgaas uc = &priv->cards[i];
14541d38fe6eSBjorn Helgaas if (uc->pdev == NULL)
14551d38fe6eSBjorn Helgaas continue;
14561d38fe6eSBjorn Helgaas vgaarb_dbg(&uc->pdev->dev, "uc->io_cnt == %d, uc->mem_cnt == %d\n",
14571d38fe6eSBjorn Helgaas uc->io_cnt, uc->mem_cnt);
14581d38fe6eSBjorn Helgaas while (uc->io_cnt--)
14591d38fe6eSBjorn Helgaas vga_put(uc->pdev, VGA_RSRC_LEGACY_IO);
14601d38fe6eSBjorn Helgaas while (uc->mem_cnt--)
14611d38fe6eSBjorn Helgaas vga_put(uc->pdev, VGA_RSRC_LEGACY_MEM);
14621d38fe6eSBjorn Helgaas }
14631d38fe6eSBjorn Helgaas spin_unlock_irqrestore(&vga_user_lock, flags);
14641d38fe6eSBjorn Helgaas
14651d38fe6eSBjorn Helgaas kfree(priv);
14661d38fe6eSBjorn Helgaas
14671d38fe6eSBjorn Helgaas return 0;
14681d38fe6eSBjorn Helgaas }
14691d38fe6eSBjorn Helgaas
14701d38fe6eSBjorn Helgaas /*
1471*cc64ca4bSSui Jingfeng * Callback any registered clients to let them know we have a change in VGA
1472*cc64ca4bSSui Jingfeng * cards.
14731d38fe6eSBjorn Helgaas */
vga_arbiter_notify_clients(void)14741d38fe6eSBjorn Helgaas static void vga_arbiter_notify_clients(void)
14751d38fe6eSBjorn Helgaas {
14761d38fe6eSBjorn Helgaas struct vga_device *vgadev;
14771d38fe6eSBjorn Helgaas unsigned long flags;
147860b4925dSSui Jingfeng unsigned int new_decodes;
14791d38fe6eSBjorn Helgaas bool new_state;
14801d38fe6eSBjorn Helgaas
14811d38fe6eSBjorn Helgaas if (!vga_arbiter_used)
14821d38fe6eSBjorn Helgaas return;
14831d38fe6eSBjorn Helgaas
1484b421364aSSui Jingfeng new_state = (vga_count > 1) ? false : true;
1485b421364aSSui Jingfeng
14861d38fe6eSBjorn Helgaas spin_lock_irqsave(&vga_lock, flags);
14871d38fe6eSBjorn Helgaas list_for_each_entry(vgadev, &vga_list, list) {
14881d38fe6eSBjorn Helgaas if (vgadev->set_decode) {
14891d38fe6eSBjorn Helgaas new_decodes = vgadev->set_decode(vgadev->pdev,
14901d38fe6eSBjorn Helgaas new_state);
14911d38fe6eSBjorn Helgaas vga_update_device_decodes(vgadev, new_decodes);
14921d38fe6eSBjorn Helgaas }
14931d38fe6eSBjorn Helgaas }
14941d38fe6eSBjorn Helgaas spin_unlock_irqrestore(&vga_lock, flags);
14951d38fe6eSBjorn Helgaas }
14961d38fe6eSBjorn Helgaas
pci_notify(struct notifier_block * nb,unsigned long action,void * data)14971d38fe6eSBjorn Helgaas static int pci_notify(struct notifier_block *nb, unsigned long action,
14981d38fe6eSBjorn Helgaas void *data)
14991d38fe6eSBjorn Helgaas {
15001d38fe6eSBjorn Helgaas struct device *dev = data;
15011d38fe6eSBjorn Helgaas struct pci_dev *pdev = to_pci_dev(dev);
15021d38fe6eSBjorn Helgaas bool notify = false;
15031d38fe6eSBjorn Helgaas
15041d38fe6eSBjorn Helgaas vgaarb_dbg(dev, "%s\n", __func__);
15051d38fe6eSBjorn Helgaas
1506*cc64ca4bSSui Jingfeng /*
1507*cc64ca4bSSui Jingfeng * For now, we're only interested in devices added and removed.
1508*cc64ca4bSSui Jingfeng * I didn't test this thing here, so someone needs to double check
1509*cc64ca4bSSui Jingfeng * for the cases of hot-pluggable VGA cards.
1510*cc64ca4bSSui Jingfeng */
15111d38fe6eSBjorn Helgaas if (action == BUS_NOTIFY_ADD_DEVICE)
15121d38fe6eSBjorn Helgaas notify = vga_arbiter_add_pci_device(pdev);
15131d38fe6eSBjorn Helgaas else if (action == BUS_NOTIFY_DEL_DEVICE)
15141d38fe6eSBjorn Helgaas notify = vga_arbiter_del_pci_device(pdev);
15151d38fe6eSBjorn Helgaas
15161d38fe6eSBjorn Helgaas if (notify)
15171d38fe6eSBjorn Helgaas vga_arbiter_notify_clients();
15181d38fe6eSBjorn Helgaas return 0;
15191d38fe6eSBjorn Helgaas }
15201d38fe6eSBjorn Helgaas
15211d38fe6eSBjorn Helgaas static struct notifier_block pci_notifier = {
15221d38fe6eSBjorn Helgaas .notifier_call = pci_notify,
15231d38fe6eSBjorn Helgaas };
15241d38fe6eSBjorn Helgaas
15251d38fe6eSBjorn Helgaas static const struct file_operations vga_arb_device_fops = {
15261d38fe6eSBjorn Helgaas .read = vga_arb_read,
15271d38fe6eSBjorn Helgaas .write = vga_arb_write,
15281d38fe6eSBjorn Helgaas .poll = vga_arb_fpoll,
15291d38fe6eSBjorn Helgaas .open = vga_arb_open,
15301d38fe6eSBjorn Helgaas .release = vga_arb_release,
15311d38fe6eSBjorn Helgaas .llseek = noop_llseek,
15321d38fe6eSBjorn Helgaas };
15331d38fe6eSBjorn Helgaas
15341d38fe6eSBjorn Helgaas static struct miscdevice vga_arb_device = {
15351d38fe6eSBjorn Helgaas MISC_DYNAMIC_MINOR, "vga_arbiter", &vga_arb_device_fops
15361d38fe6eSBjorn Helgaas };
15371d38fe6eSBjorn Helgaas
vga_arb_device_init(void)15381d38fe6eSBjorn Helgaas static int __init vga_arb_device_init(void)
15391d38fe6eSBjorn Helgaas {
15401d38fe6eSBjorn Helgaas int rc;
15411d38fe6eSBjorn Helgaas struct pci_dev *pdev;
15421d38fe6eSBjorn Helgaas
15431d38fe6eSBjorn Helgaas rc = misc_register(&vga_arb_device);
15441d38fe6eSBjorn Helgaas if (rc < 0)
15451d38fe6eSBjorn Helgaas pr_err("error %d registering device\n", rc);
15461d38fe6eSBjorn Helgaas
15471d38fe6eSBjorn Helgaas bus_register_notifier(&pci_bus_type, &pci_notifier);
15481d38fe6eSBjorn Helgaas
1549*cc64ca4bSSui Jingfeng /* Add all VGA class PCI devices by default */
15501d38fe6eSBjorn Helgaas pdev = NULL;
15511d38fe6eSBjorn Helgaas while ((pdev =
15521d38fe6eSBjorn Helgaas pci_get_subsys(PCI_ANY_ID, PCI_ANY_ID, PCI_ANY_ID,
15531d38fe6eSBjorn Helgaas PCI_ANY_ID, pdev)) != NULL)
15541d38fe6eSBjorn Helgaas vga_arbiter_add_pci_device(pdev);
15551d38fe6eSBjorn Helgaas
15561d38fe6eSBjorn Helgaas pr_info("loaded\n");
15571d38fe6eSBjorn Helgaas return rc;
15581d38fe6eSBjorn Helgaas }
15591d38fe6eSBjorn Helgaas subsys_initcall_sync(vga_arb_device_init);
1560