Bjorn Helgaas | f321c35 | 2022-02-24 16:47:53 -0600 | [diff] [blame] | 1 | // SPDX-License-Identifier: MIT |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 2 | /* |
Tiago Vignatti | c0db9cb | 2010-05-24 18:24:31 +0300 | [diff] [blame] | 3 | * vgaarb.c: Implements the VGA arbitration. For details refer to |
Mauro Carvalho Chehab | 5fb94e9 | 2018-05-08 15:14:57 -0300 | [diff] [blame] | 4 | * Documentation/gpu/vgaarbiter.rst |
Tiago Vignatti | c0db9cb | 2010-05-24 18:24:31 +0300 | [diff] [blame] | 5 | * |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 6 | * (C) Copyright 2005 Benjamin Herrenschmidt <benh@kernel.crashing.org> |
| 7 | * (C) Copyright 2007 Paulo R. Zanoni <przanoni@gmail.com> |
| 8 | * (C) Copyright 2007, 2009 Tiago Vignatti <vignatti@freedesktop.org> |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 9 | */ |
| 10 | |
Thierry Reding | 8b7e2e8 | 2015-08-12 16:32:06 +0200 | [diff] [blame] | 11 | #define pr_fmt(fmt) "vgaarb: " fmt |
| 12 | |
Bjorn Helgaas | a75d68f | 2016-11-17 11:47:58 -0600 | [diff] [blame] | 13 | #define vgaarb_dbg(dev, fmt, arg...) dev_dbg(dev, "vgaarb: " fmt, ##arg) |
| 14 | #define vgaarb_info(dev, fmt, arg...) dev_info(dev, "vgaarb: " fmt, ##arg) |
| 15 | #define vgaarb_err(dev, fmt, arg...) dev_err(dev, "vgaarb: " fmt, ##arg) |
| 16 | |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 17 | #include <linux/module.h> |
| 18 | #include <linux/kernel.h> |
| 19 | #include <linux/pci.h> |
| 20 | #include <linux/errno.h> |
| 21 | #include <linux/init.h> |
| 22 | #include <linux/list.h> |
Ingo Molnar | 174cd4b | 2017-02-02 19:15:33 +0100 | [diff] [blame] | 23 | #include <linux/sched/signal.h> |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 24 | #include <linux/wait.h> |
| 25 | #include <linux/spinlock.h> |
| 26 | #include <linux/poll.h> |
| 27 | #include <linux/miscdevice.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 28 | #include <linux/slab.h> |
Bruno Prémont | 86fd887 | 2014-08-24 23:09:53 +0200 | [diff] [blame] | 29 | #include <linux/screen_info.h> |
Gerd Hoffmann | c6b38fb | 2019-03-01 10:24:59 +0100 | [diff] [blame] | 30 | #include <linux/vt.h> |
| 31 | #include <linux/console.h> |
Kai-Heng Feng | 808a4ae | 2021-05-19 21:57:23 +0800 | [diff] [blame] | 32 | #include <linux/acpi.h> |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 33 | |
| 34 | #include <linux/uaccess.h> |
| 35 | |
| 36 | #include <linux/vgaarb.h> |
| 37 | |
| 38 | static void vga_arbiter_notify_clients(void); |
| 39 | /* |
| 40 | * We keep a list of all vga devices in the system to speed |
| 41 | * up the various operations of the arbiter |
| 42 | */ |
| 43 | struct vga_device { |
| 44 | struct list_head list; |
| 45 | struct pci_dev *pdev; |
| 46 | unsigned int decodes; /* what does it decodes */ |
| 47 | unsigned int owns; /* what does it owns */ |
| 48 | unsigned int locks; /* what does it locks */ |
| 49 | unsigned int io_lock_cnt; /* legacy IO lock count */ |
| 50 | unsigned int mem_lock_cnt; /* legacy MEM lock count */ |
| 51 | unsigned int io_norm_cnt; /* normal IO count */ |
| 52 | unsigned int mem_norm_cnt; /* normal MEM count */ |
Dave Airlie | 3448a19 | 2010-06-01 15:32:24 +1000 | [diff] [blame] | 53 | bool bridge_has_one_vga; |
Huacai Chen | f8d81df | 2022-02-24 16:47:47 -0600 | [diff] [blame] | 54 | bool is_firmware_default; /* device selected by firmware */ |
Christoph Hellwig | bf44e8c | 2021-07-16 08:16:34 +0200 | [diff] [blame] | 55 | unsigned int (*set_decode)(struct pci_dev *pdev, bool decode); |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 56 | }; |
| 57 | |
| 58 | static LIST_HEAD(vga_list); |
| 59 | static int vga_count, vga_decode_count; |
| 60 | static bool vga_arbiter_used; |
| 61 | static DEFINE_SPINLOCK(vga_lock); |
| 62 | static DECLARE_WAIT_QUEUE_HEAD(vga_wait_queue); |
| 63 | |
| 64 | |
| 65 | static const char *vga_iostate_to_str(unsigned int iostate) |
| 66 | { |
| 67 | /* Ignore VGA_RSRC_IO and VGA_RSRC_MEM */ |
| 68 | iostate &= VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM; |
| 69 | switch (iostate) { |
| 70 | case VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM: |
| 71 | return "io+mem"; |
| 72 | case VGA_RSRC_LEGACY_IO: |
| 73 | return "io"; |
| 74 | case VGA_RSRC_LEGACY_MEM: |
| 75 | return "mem"; |
| 76 | } |
| 77 | return "none"; |
| 78 | } |
| 79 | |
| 80 | static int vga_str_to_iostate(char *buf, int str_size, int *io_state) |
| 81 | { |
| 82 | /* we could in theory hand out locks on IO and mem |
| 83 | * separately to userspace but it can cause deadlocks */ |
| 84 | if (strncmp(buf, "none", 4) == 0) { |
| 85 | *io_state = VGA_RSRC_NONE; |
| 86 | return 1; |
| 87 | } |
| 88 | |
| 89 | /* XXX We're not chekcing the str_size! */ |
| 90 | if (strncmp(buf, "io+mem", 6) == 0) |
| 91 | goto both; |
| 92 | else if (strncmp(buf, "io", 2) == 0) |
| 93 | goto both; |
| 94 | else if (strncmp(buf, "mem", 3) == 0) |
| 95 | goto both; |
| 96 | return 0; |
| 97 | both: |
| 98 | *io_state = VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM; |
| 99 | return 1; |
| 100 | } |
| 101 | |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 102 | /* this is only used a cookie - it should not be dereferenced */ |
| 103 | static struct pci_dev *vga_default; |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 104 | |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 105 | /* Find somebody in our list */ |
| 106 | static struct vga_device *vgadev_find(struct pci_dev *pdev) |
| 107 | { |
| 108 | struct vga_device *vgadev; |
| 109 | |
| 110 | list_for_each_entry(vgadev, &vga_list, list) |
| 111 | if (pdev == vgadev->pdev) |
| 112 | return vgadev; |
| 113 | return NULL; |
| 114 | } |
| 115 | |
Daniel Vetter | b754b35 | 2016-08-12 22:48:56 +0200 | [diff] [blame] | 116 | /** |
| 117 | * vga_default_device - return the default VGA device, for vgacon |
| 118 | * |
| 119 | * This can be defined by the platform. The default implementation |
| 120 | * is rather dumb and will probably only work properly on single |
| 121 | * vga card setups and/or x86 platforms. |
| 122 | * |
| 123 | * If your VGA default device is not PCI, you'll have to return |
| 124 | * NULL here. In this case, I assume it will not conflict with |
| 125 | * any PCI card. If this is not true, I'll have to define two archs |
| 126 | * hooks for enabling/disabling the VGA default device if that is |
| 127 | * possible. This may be a problem with real _ISA_ VGA cards, in |
| 128 | * addition to a PCI one. I don't know at this point how to deal |
| 129 | * with that card. Can theirs IOs be disabled at all ? If not, then |
| 130 | * I suppose it's a matter of having the proper arch hook telling |
| 131 | * us about it, so we basically never allow anybody to succeed a |
| 132 | * vga_get()... |
| 133 | */ |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 134 | struct pci_dev *vga_default_device(void) |
| 135 | { |
| 136 | return vga_default; |
| 137 | } |
Matthew Garrett | 1b23170 | 2012-04-24 09:31:28 +0100 | [diff] [blame] | 138 | EXPORT_SYMBOL_GPL(vga_default_device); |
| 139 | |
Matthew Garrett | 1a39b31 | 2012-04-16 16:26:02 -0400 | [diff] [blame] | 140 | void vga_set_default_device(struct pci_dev *pdev) |
| 141 | { |
Yinghai Lu | 84544a1 | 2012-09-19 11:54:15 -0700 | [diff] [blame] | 142 | if (vga_default == pdev) |
| 143 | return; |
| 144 | |
| 145 | pci_dev_put(vga_default); |
| 146 | vga_default = pci_dev_get(pdev); |
Matthew Garrett | 1a39b31 | 2012-04-16 16:26:02 -0400 | [diff] [blame] | 147 | } |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 148 | |
Gerd Hoffmann | c6b38fb | 2019-03-01 10:24:59 +0100 | [diff] [blame] | 149 | /** |
| 150 | * vga_remove_vgacon - deactivete vga console |
| 151 | * |
| 152 | * Unbind and unregister vgacon in case pdev is the default vga |
| 153 | * device. Can be called by gpu drivers on initialization to make |
| 154 | * sure vga register access done by vgacon will not disturb the |
| 155 | * device. |
| 156 | * |
| 157 | * @pdev: pci device. |
| 158 | */ |
| 159 | #if !defined(CONFIG_VGA_CONSOLE) |
| 160 | int vga_remove_vgacon(struct pci_dev *pdev) |
| 161 | { |
| 162 | return 0; |
| 163 | } |
| 164 | #elif !defined(CONFIG_DUMMY_CONSOLE) |
| 165 | int vga_remove_vgacon(struct pci_dev *pdev) |
| 166 | { |
| 167 | return -ENODEV; |
| 168 | } |
| 169 | #else |
| 170 | int vga_remove_vgacon(struct pci_dev *pdev) |
| 171 | { |
| 172 | int ret = 0; |
| 173 | |
| 174 | if (pdev != vga_default) |
| 175 | return 0; |
| 176 | vgaarb_info(&pdev->dev, "deactivate vga console\n"); |
| 177 | |
| 178 | console_lock(); |
| 179 | if (con_is_bound(&vga_con)) |
| 180 | ret = do_take_over_console(&dummy_con, 0, |
| 181 | MAX_NR_CONSOLES - 1, 1); |
| 182 | if (ret == 0) { |
| 183 | ret = do_unregister_con_driver(&vga_con); |
| 184 | |
| 185 | /* Ignore "already unregistered". */ |
| 186 | if (ret == -ENODEV) |
| 187 | ret = 0; |
| 188 | } |
| 189 | console_unlock(); |
| 190 | |
| 191 | return ret; |
| 192 | } |
| 193 | #endif |
| 194 | EXPORT_SYMBOL(vga_remove_vgacon); |
| 195 | |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 196 | /* If we don't ever use VGA arb we should avoid |
| 197 | turning off anything anywhere due to old X servers getting |
| 198 | confused about the boot device not being VGA */ |
| 199 | static void vga_check_first_use(void) |
| 200 | { |
| 201 | /* we should inform all GPUs in the system that |
Lucas De Marchi | 25985ed | 2011-03-30 22:57:33 -0300 | [diff] [blame] | 202 | * VGA arb has occurred and to try and disable resources |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 203 | * if they can */ |
| 204 | if (!vga_arbiter_used) { |
| 205 | vga_arbiter_used = true; |
| 206 | vga_arbiter_notify_clients(); |
| 207 | } |
| 208 | } |
| 209 | |
| 210 | static struct vga_device *__vga_tryget(struct vga_device *vgadev, |
| 211 | unsigned int rsrc) |
| 212 | { |
Bjorn Helgaas | a75d68f | 2016-11-17 11:47:58 -0600 | [diff] [blame] | 213 | struct device *dev = &vgadev->pdev->dev; |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 214 | unsigned int wants, legacy_wants, match; |
| 215 | struct vga_device *conflict; |
| 216 | unsigned int pci_bits; |
Dave Airlie | 3448a19 | 2010-06-01 15:32:24 +1000 | [diff] [blame] | 217 | u32 flags = 0; |
| 218 | |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 219 | /* Account for "normal" resources to lock. If we decode the legacy, |
| 220 | * counterpart, we need to request it as well |
| 221 | */ |
| 222 | if ((rsrc & VGA_RSRC_NORMAL_IO) && |
| 223 | (vgadev->decodes & VGA_RSRC_LEGACY_IO)) |
| 224 | rsrc |= VGA_RSRC_LEGACY_IO; |
| 225 | if ((rsrc & VGA_RSRC_NORMAL_MEM) && |
| 226 | (vgadev->decodes & VGA_RSRC_LEGACY_MEM)) |
| 227 | rsrc |= VGA_RSRC_LEGACY_MEM; |
| 228 | |
Bjorn Helgaas | a75d68f | 2016-11-17 11:47:58 -0600 | [diff] [blame] | 229 | vgaarb_dbg(dev, "%s: %d\n", __func__, rsrc); |
| 230 | vgaarb_dbg(dev, "%s: owns: %d\n", __func__, vgadev->owns); |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 231 | |
| 232 | /* Check what resources we need to acquire */ |
| 233 | wants = rsrc & ~vgadev->owns; |
| 234 | |
| 235 | /* We already own everything, just mark locked & bye bye */ |
| 236 | if (wants == 0) |
| 237 | goto lock_them; |
| 238 | |
| 239 | /* We don't need to request a legacy resource, we just enable |
| 240 | * appropriate decoding and go |
| 241 | */ |
| 242 | legacy_wants = wants & VGA_RSRC_LEGACY_MASK; |
| 243 | if (legacy_wants == 0) |
| 244 | goto enable_them; |
| 245 | |
| 246 | /* Ok, we don't, let's find out how we need to kick off */ |
| 247 | list_for_each_entry(conflict, &vga_list, list) { |
| 248 | unsigned int lwants = legacy_wants; |
| 249 | unsigned int change_bridge = 0; |
| 250 | |
| 251 | /* Don't conflict with myself */ |
| 252 | if (vgadev == conflict) |
| 253 | continue; |
| 254 | |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 255 | /* We have a possible conflict. before we go further, we must |
| 256 | * check if we sit on the same bus as the conflicting device. |
| 257 | * if we don't, then we must tie both IO and MEM resources |
| 258 | * together since there is only a single bit controlling |
| 259 | * VGA forwarding on P2P bridges |
| 260 | */ |
| 261 | if (vgadev->pdev->bus != conflict->pdev->bus) { |
| 262 | change_bridge = 1; |
| 263 | lwants = VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM; |
| 264 | } |
| 265 | |
| 266 | /* Check if the guy has a lock on the resource. If he does, |
| 267 | * return the conflicting entry |
| 268 | */ |
| 269 | if (conflict->locks & lwants) |
| 270 | return conflict; |
| 271 | |
Alex Williamson | 4e4e7dc | 2014-07-03 09:59:51 -0600 | [diff] [blame] | 272 | /* Ok, now check if it owns the resource we want. We can |
| 273 | * lock resources that are not decoded, therefore a device |
| 274 | * can own resources it doesn't decode. |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 275 | */ |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 276 | match = lwants & conflict->owns; |
| 277 | if (!match) |
| 278 | continue; |
| 279 | |
| 280 | /* looks like he doesn't have a lock, we can steal |
| 281 | * them from him |
| 282 | */ |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 283 | |
Dave Airlie | 3448a19 | 2010-06-01 15:32:24 +1000 | [diff] [blame] | 284 | flags = 0; |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 285 | pci_bits = 0; |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 286 | |
Alex Williamson | 4e4e7dc | 2014-07-03 09:59:51 -0600 | [diff] [blame] | 287 | /* If we can't control legacy resources via the bridge, we |
| 288 | * also need to disable normal decoding. |
| 289 | */ |
Dave Airlie | 3448a19 | 2010-06-01 15:32:24 +1000 | [diff] [blame] | 290 | if (!conflict->bridge_has_one_vga) { |
Alex Williamson | 4e4e7dc | 2014-07-03 09:59:51 -0600 | [diff] [blame] | 291 | if ((match & conflict->decodes) & VGA_RSRC_LEGACY_MEM) |
Dave Airlie | 3448a19 | 2010-06-01 15:32:24 +1000 | [diff] [blame] | 292 | pci_bits |= PCI_COMMAND_MEMORY; |
Alex Williamson | 4e4e7dc | 2014-07-03 09:59:51 -0600 | [diff] [blame] | 293 | if ((match & conflict->decodes) & VGA_RSRC_LEGACY_IO) |
Dave Airlie | 3448a19 | 2010-06-01 15:32:24 +1000 | [diff] [blame] | 294 | pci_bits |= PCI_COMMAND_IO; |
Alex Williamson | 4e4e7dc | 2014-07-03 09:59:51 -0600 | [diff] [blame] | 295 | |
Christoph Hellwig | f6b1772 | 2021-07-16 08:16:33 +0200 | [diff] [blame] | 296 | if (pci_bits) |
Alex Williamson | 4e4e7dc | 2014-07-03 09:59:51 -0600 | [diff] [blame] | 297 | flags |= PCI_VGA_STATE_CHANGE_DECODES; |
Dave Airlie | 3448a19 | 2010-06-01 15:32:24 +1000 | [diff] [blame] | 298 | } |
| 299 | |
| 300 | if (change_bridge) |
| 301 | flags |= PCI_VGA_STATE_CHANGE_BRIDGE; |
| 302 | |
| 303 | pci_set_vga_state(conflict->pdev, false, pci_bits, flags); |
Alex Williamson | f22d776 | 2013-08-15 16:37:53 -0600 | [diff] [blame] | 304 | conflict->owns &= ~match; |
Alex Williamson | 4e4e7dc | 2014-07-03 09:59:51 -0600 | [diff] [blame] | 305 | |
| 306 | /* If we disabled normal decoding, reflect it in owns */ |
| 307 | if (pci_bits & PCI_COMMAND_MEMORY) |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 308 | conflict->owns &= ~VGA_RSRC_NORMAL_MEM; |
Alex Williamson | 4e4e7dc | 2014-07-03 09:59:51 -0600 | [diff] [blame] | 309 | if (pci_bits & PCI_COMMAND_IO) |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 310 | conflict->owns &= ~VGA_RSRC_NORMAL_IO; |
| 311 | } |
| 312 | |
| 313 | enable_them: |
| 314 | /* ok dude, we got it, everybody conflicting has been disabled, let's |
Alex Williamson | 4e4e7dc | 2014-07-03 09:59:51 -0600 | [diff] [blame] | 315 | * enable us. Mark any bits in "owns" regardless of whether we |
| 316 | * decoded them. We can lock resources we don't decode, therefore |
| 317 | * we must track them via "owns". |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 318 | */ |
Dave Airlie | 3448a19 | 2010-06-01 15:32:24 +1000 | [diff] [blame] | 319 | flags = 0; |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 320 | pci_bits = 0; |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 321 | |
Dave Airlie | 3448a19 | 2010-06-01 15:32:24 +1000 | [diff] [blame] | 322 | if (!vgadev->bridge_has_one_vga) { |
| 323 | flags |= PCI_VGA_STATE_CHANGE_DECODES; |
| 324 | if (wants & (VGA_RSRC_LEGACY_MEM|VGA_RSRC_NORMAL_MEM)) |
| 325 | pci_bits |= PCI_COMMAND_MEMORY; |
| 326 | if (wants & (VGA_RSRC_LEGACY_IO|VGA_RSRC_NORMAL_IO)) |
| 327 | pci_bits |= PCI_COMMAND_IO; |
| 328 | } |
Alex Williamson | 4e4e7dc | 2014-07-03 09:59:51 -0600 | [diff] [blame] | 329 | if (wants & VGA_RSRC_LEGACY_MASK) |
Dave Airlie | 3448a19 | 2010-06-01 15:32:24 +1000 | [diff] [blame] | 330 | flags |= PCI_VGA_STATE_CHANGE_BRIDGE; |
| 331 | |
| 332 | pci_set_vga_state(vgadev->pdev, true, pci_bits, flags); |
| 333 | |
Alex Williamson | 4e4e7dc | 2014-07-03 09:59:51 -0600 | [diff] [blame] | 334 | vgadev->owns |= wants; |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 335 | lock_them: |
| 336 | vgadev->locks |= (rsrc & VGA_RSRC_LEGACY_MASK); |
| 337 | if (rsrc & VGA_RSRC_LEGACY_IO) |
| 338 | vgadev->io_lock_cnt++; |
| 339 | if (rsrc & VGA_RSRC_LEGACY_MEM) |
| 340 | vgadev->mem_lock_cnt++; |
| 341 | if (rsrc & VGA_RSRC_NORMAL_IO) |
| 342 | vgadev->io_norm_cnt++; |
| 343 | if (rsrc & VGA_RSRC_NORMAL_MEM) |
| 344 | vgadev->mem_norm_cnt++; |
| 345 | |
| 346 | return NULL; |
| 347 | } |
| 348 | |
| 349 | static void __vga_put(struct vga_device *vgadev, unsigned int rsrc) |
| 350 | { |
Bjorn Helgaas | a75d68f | 2016-11-17 11:47:58 -0600 | [diff] [blame] | 351 | struct device *dev = &vgadev->pdev->dev; |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 352 | unsigned int old_locks = vgadev->locks; |
| 353 | |
Bjorn Helgaas | a75d68f | 2016-11-17 11:47:58 -0600 | [diff] [blame] | 354 | vgaarb_dbg(dev, "%s\n", __func__); |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 355 | |
| 356 | /* Update our counters, and account for equivalent legacy resources |
| 357 | * if we decode them |
| 358 | */ |
| 359 | if ((rsrc & VGA_RSRC_NORMAL_IO) && vgadev->io_norm_cnt > 0) { |
| 360 | vgadev->io_norm_cnt--; |
| 361 | if (vgadev->decodes & VGA_RSRC_LEGACY_IO) |
| 362 | rsrc |= VGA_RSRC_LEGACY_IO; |
| 363 | } |
| 364 | if ((rsrc & VGA_RSRC_NORMAL_MEM) && vgadev->mem_norm_cnt > 0) { |
| 365 | vgadev->mem_norm_cnt--; |
| 366 | if (vgadev->decodes & VGA_RSRC_LEGACY_MEM) |
| 367 | rsrc |= VGA_RSRC_LEGACY_MEM; |
| 368 | } |
| 369 | if ((rsrc & VGA_RSRC_LEGACY_IO) && vgadev->io_lock_cnt > 0) |
| 370 | vgadev->io_lock_cnt--; |
| 371 | if ((rsrc & VGA_RSRC_LEGACY_MEM) && vgadev->mem_lock_cnt > 0) |
| 372 | vgadev->mem_lock_cnt--; |
| 373 | |
| 374 | /* Just clear lock bits, we do lazy operations so we don't really |
| 375 | * have to bother about anything else at this point |
| 376 | */ |
| 377 | if (vgadev->io_lock_cnt == 0) |
| 378 | vgadev->locks &= ~VGA_RSRC_LEGACY_IO; |
| 379 | if (vgadev->mem_lock_cnt == 0) |
| 380 | vgadev->locks &= ~VGA_RSRC_LEGACY_MEM; |
| 381 | |
| 382 | /* Kick the wait queue in case somebody was waiting if we actually |
| 383 | * released something |
| 384 | */ |
| 385 | if (old_locks != vgadev->locks) |
| 386 | wake_up_all(&vga_wait_queue); |
| 387 | } |
| 388 | |
Daniel Vetter | b754b35 | 2016-08-12 22:48:56 +0200 | [diff] [blame] | 389 | /** |
| 390 | * vga_get - acquire & locks VGA resources |
| 391 | * @pdev: pci device of the VGA card or NULL for the system default |
| 392 | * @rsrc: bit mask of resources to acquire and lock |
| 393 | * @interruptible: blocking should be interruptible by signals ? |
| 394 | * |
| 395 | * This function acquires VGA resources for the given card and mark those |
| 396 | * resources locked. If the resource requested are "normal" (and not legacy) |
| 397 | * resources, the arbiter will first check whether the card is doing legacy |
| 398 | * decoding for that type of resource. If yes, the lock is "converted" into a |
| 399 | * legacy resource lock. |
| 400 | * |
| 401 | * The arbiter will first look for all VGA cards that might conflict and disable |
| 402 | * their IOs and/or Memory access, including VGA forwarding on P2P bridges if |
| 403 | * necessary, so that the requested resources can be used. Then, the card is |
| 404 | * marked as locking these resources and the IO and/or Memory accesses are |
| 405 | * enabled on the card (including VGA forwarding on parent P2P bridges if any). |
| 406 | * |
| 407 | * This function will block if some conflicting card is already locking one of |
| 408 | * the required resources (or any resource on a different bus segment, since P2P |
| 409 | * bridges don't differentiate VGA memory and IO afaik). You can indicate |
| 410 | * whether this blocking should be interruptible by a signal (for userland |
| 411 | * interface) or not. |
| 412 | * |
| 413 | * Must not be called at interrupt time or in atomic context. If the card |
| 414 | * already owns the resources, the function succeeds. Nested calls are |
| 415 | * supported (a per-resource counter is maintained) |
| 416 | * |
| 417 | * On success, release the VGA resource again with vga_put(). |
| 418 | * |
| 419 | * Returns: |
| 420 | * |
| 421 | * 0 on success, negative error code on failure. |
| 422 | */ |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 423 | int vga_get(struct pci_dev *pdev, unsigned int rsrc, int interruptible) |
| 424 | { |
| 425 | struct vga_device *vgadev, *conflict; |
| 426 | unsigned long flags; |
Ingo Molnar | ac6424b | 2017-06-20 12:06:13 +0200 | [diff] [blame] | 427 | wait_queue_entry_t wait; |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 428 | int rc = 0; |
| 429 | |
| 430 | vga_check_first_use(); |
| 431 | /* The one who calls us should check for this, but lets be sure... */ |
| 432 | if (pdev == NULL) |
| 433 | pdev = vga_default_device(); |
| 434 | if (pdev == NULL) |
| 435 | return 0; |
| 436 | |
| 437 | for (;;) { |
| 438 | spin_lock_irqsave(&vga_lock, flags); |
| 439 | vgadev = vgadev_find(pdev); |
| 440 | if (vgadev == NULL) { |
| 441 | spin_unlock_irqrestore(&vga_lock, flags); |
| 442 | rc = -ENODEV; |
| 443 | break; |
| 444 | } |
| 445 | conflict = __vga_tryget(vgadev, rsrc); |
| 446 | spin_unlock_irqrestore(&vga_lock, flags); |
| 447 | if (conflict == NULL) |
| 448 | break; |
| 449 | |
| 450 | |
| 451 | /* We have a conflict, we wait until somebody kicks the |
| 452 | * work queue. Currently we have one work queue that we |
| 453 | * kick each time some resources are released, but it would |
| 454 | * be fairly easy to have a per device one so that we only |
| 455 | * need to attach to the conflicting device |
| 456 | */ |
| 457 | init_waitqueue_entry(&wait, current); |
| 458 | add_wait_queue(&vga_wait_queue, &wait); |
| 459 | set_current_state(interruptible ? |
| 460 | TASK_INTERRUPTIBLE : |
| 461 | TASK_UNINTERRUPTIBLE); |
Kirill A. Shutemov | 9f5bd30 | 2015-11-30 04:17:31 +0200 | [diff] [blame] | 462 | if (interruptible && signal_pending(current)) { |
| 463 | __set_current_state(TASK_RUNNING); |
| 464 | remove_wait_queue(&vga_wait_queue, &wait); |
| 465 | rc = -ERESTARTSYS; |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 466 | break; |
| 467 | } |
| 468 | schedule(); |
| 469 | remove_wait_queue(&vga_wait_queue, &wait); |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 470 | } |
| 471 | return rc; |
| 472 | } |
| 473 | EXPORT_SYMBOL(vga_get); |
| 474 | |
Daniel Vetter | b754b35 | 2016-08-12 22:48:56 +0200 | [diff] [blame] | 475 | /** |
| 476 | * vga_tryget - try to acquire & lock legacy VGA resources |
| 477 | * @pdev: pci devivce of VGA card or NULL for system default |
| 478 | * @rsrc: bit mask of resources to acquire and lock |
| 479 | * |
| 480 | * This function performs the same operation as vga_get(), but will return an |
| 481 | * error (-EBUSY) instead of blocking if the resources are already locked by |
| 482 | * another card. It can be called in any context |
| 483 | * |
| 484 | * On success, release the VGA resource again with vga_put(). |
| 485 | * |
| 486 | * Returns: |
| 487 | * |
| 488 | * 0 on success, negative error code on failure. |
| 489 | */ |
Christoph Hellwig | f369bc3 | 2020-08-01 08:17:13 +0200 | [diff] [blame] | 490 | static int vga_tryget(struct pci_dev *pdev, unsigned int rsrc) |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 491 | { |
| 492 | struct vga_device *vgadev; |
| 493 | unsigned long flags; |
| 494 | int rc = 0; |
| 495 | |
| 496 | vga_check_first_use(); |
| 497 | |
| 498 | /* The one who calls us should check for this, but lets be sure... */ |
| 499 | if (pdev == NULL) |
| 500 | pdev = vga_default_device(); |
| 501 | if (pdev == NULL) |
| 502 | return 0; |
| 503 | spin_lock_irqsave(&vga_lock, flags); |
| 504 | vgadev = vgadev_find(pdev); |
| 505 | if (vgadev == NULL) { |
| 506 | rc = -ENODEV; |
| 507 | goto bail; |
| 508 | } |
| 509 | if (__vga_tryget(vgadev, rsrc)) |
| 510 | rc = -EBUSY; |
| 511 | bail: |
| 512 | spin_unlock_irqrestore(&vga_lock, flags); |
| 513 | return rc; |
| 514 | } |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 515 | |
Daniel Vetter | b754b35 | 2016-08-12 22:48:56 +0200 | [diff] [blame] | 516 | /** |
| 517 | * vga_put - release lock on legacy VGA resources |
| 518 | * @pdev: pci device of VGA card or NULL for system default |
| 519 | * @rsrc: but mask of resource to release |
| 520 | * |
| 521 | * This fuction releases resources previously locked by vga_get() or |
| 522 | * vga_tryget(). The resources aren't disabled right away, so that a subsequence |
| 523 | * vga_get() on the same card will succeed immediately. Resources have a |
| 524 | * counter, so locks are only released if the counter reaches 0. |
| 525 | */ |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 526 | void vga_put(struct pci_dev *pdev, unsigned int rsrc) |
| 527 | { |
| 528 | struct vga_device *vgadev; |
| 529 | unsigned long flags; |
| 530 | |
| 531 | /* The one who calls us should check for this, but lets be sure... */ |
| 532 | if (pdev == NULL) |
| 533 | pdev = vga_default_device(); |
| 534 | if (pdev == NULL) |
| 535 | return; |
| 536 | spin_lock_irqsave(&vga_lock, flags); |
| 537 | vgadev = vgadev_find(pdev); |
| 538 | if (vgadev == NULL) |
| 539 | goto bail; |
| 540 | __vga_put(vgadev, rsrc); |
| 541 | bail: |
| 542 | spin_unlock_irqrestore(&vga_lock, flags); |
| 543 | } |
| 544 | EXPORT_SYMBOL(vga_put); |
| 545 | |
Huacai Chen | f8d81df | 2022-02-24 16:47:47 -0600 | [diff] [blame] | 546 | static bool vga_is_firmware_default(struct pci_dev *pdev) |
Bjorn Helgaas | 60a9bac | 2022-02-24 16:47:45 -0600 | [diff] [blame] | 547 | { |
| 548 | #if defined(CONFIG_X86) || defined(CONFIG_IA64) |
Bjorn Helgaas | 60a9bac | 2022-02-24 16:47:45 -0600 | [diff] [blame] | 549 | u64 base = screen_info.lfb_base; |
| 550 | u64 size = screen_info.lfb_size; |
| 551 | u64 limit; |
| 552 | resource_size_t start, end; |
| 553 | unsigned long flags; |
| 554 | int i; |
| 555 | |
| 556 | /* Select the device owning the boot framebuffer if there is one */ |
| 557 | |
| 558 | if (screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE) |
| 559 | base |= (u64)screen_info.ext_lfb_base << 32; |
| 560 | |
| 561 | limit = base + size; |
| 562 | |
Bjorn Helgaas | 60a9bac | 2022-02-24 16:47:45 -0600 | [diff] [blame] | 563 | /* Does firmware framebuffer belong to us? */ |
| 564 | for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) { |
| 565 | flags = pci_resource_flags(pdev, i); |
| 566 | |
| 567 | if ((flags & IORESOURCE_MEM) == 0) |
| 568 | continue; |
| 569 | |
| 570 | start = pci_resource_start(pdev, i); |
| 571 | end = pci_resource_end(pdev, i); |
| 572 | |
| 573 | if (!start || !end) |
| 574 | continue; |
| 575 | |
| 576 | if (base < start || limit >= end) |
| 577 | continue; |
| 578 | |
Huacai Chen | f8d81df | 2022-02-24 16:47:47 -0600 | [diff] [blame] | 579 | return true; |
Bjorn Helgaas | 60a9bac | 2022-02-24 16:47:45 -0600 | [diff] [blame] | 580 | } |
| 581 | #endif |
Huacai Chen | f8d81df | 2022-02-24 16:47:47 -0600 | [diff] [blame] | 582 | return false; |
Bjorn Helgaas | 60a9bac | 2022-02-24 16:47:45 -0600 | [diff] [blame] | 583 | } |
| 584 | |
Huacai Chen | c1593dd | 2022-02-24 16:47:44 -0600 | [diff] [blame] | 585 | static bool vga_arb_integrated_gpu(struct device *dev) |
| 586 | { |
| 587 | #if defined(CONFIG_ACPI) |
| 588 | struct acpi_device *adev = ACPI_COMPANION(dev); |
| 589 | |
| 590 | return adev && !strcmp(acpi_device_hid(adev), ACPI_VIDEO_HID); |
| 591 | #else |
| 592 | return false; |
| 593 | #endif |
| 594 | } |
| 595 | |
Thierry Reding | 5d90ccf | 2015-08-12 16:32:07 +0200 | [diff] [blame] | 596 | /* |
Huacai Chen | dfe3da8 | 2022-02-24 16:47:46 -0600 | [diff] [blame] | 597 | * Return true if vgadev is a better default VGA device than the best one |
| 598 | * we've seen so far. |
| 599 | */ |
| 600 | static bool vga_is_boot_device(struct vga_device *vgadev) |
| 601 | { |
| 602 | struct vga_device *boot_vga = vgadev_find(vga_default_device()); |
Huacai Chen | f8d81df | 2022-02-24 16:47:47 -0600 | [diff] [blame] | 603 | struct pci_dev *pdev = vgadev->pdev; |
Huacai Chen | e96902e | 2022-02-24 16:47:48 -0600 | [diff] [blame] | 604 | u16 cmd, boot_cmd; |
Huacai Chen | dfe3da8 | 2022-02-24 16:47:46 -0600 | [diff] [blame] | 605 | |
| 606 | /* |
| 607 | * We select the default VGA device in this order: |
| 608 | * Firmware framebuffer (see vga_arb_select_default_device()) |
| 609 | * Legacy VGA device (owns VGA_RSRC_LEGACY_MASK) |
| 610 | * Non-legacy integrated device (see vga_arb_select_default_device()) |
| 611 | * Non-legacy discrete device (see vga_arb_select_default_device()) |
| 612 | * Other device (see vga_arb_select_default_device()) |
| 613 | */ |
| 614 | |
| 615 | /* |
Huacai Chen | f8d81df | 2022-02-24 16:47:47 -0600 | [diff] [blame] | 616 | * We always prefer a firmware default device, so if we've already |
| 617 | * found one, there's no need to consider vgadev. |
| 618 | */ |
| 619 | if (boot_vga && boot_vga->is_firmware_default) |
| 620 | return false; |
| 621 | |
| 622 | if (vga_is_firmware_default(pdev)) { |
| 623 | vgadev->is_firmware_default = true; |
| 624 | return true; |
| 625 | } |
| 626 | |
| 627 | /* |
Huacai Chen | dfe3da8 | 2022-02-24 16:47:46 -0600 | [diff] [blame] | 628 | * A legacy VGA device has MEM and IO enabled and any bridges |
| 629 | * leading to it have PCI_BRIDGE_CTL_VGA enabled so the legacy |
| 630 | * resources ([mem 0xa0000-0xbffff], [io 0x3b0-0x3bb], etc) are |
| 631 | * routed to it. |
| 632 | * |
| 633 | * We use the first one we find, so if we've already found one, |
| 634 | * vgadev is no better. |
| 635 | */ |
Huacai Chen | 37114e4 | 2022-02-24 16:47:49 -0600 | [diff] [blame] | 636 | if (boot_vga && |
| 637 | (boot_vga->owns & VGA_RSRC_LEGACY_MASK) == VGA_RSRC_LEGACY_MASK) |
Huacai Chen | dfe3da8 | 2022-02-24 16:47:46 -0600 | [diff] [blame] | 638 | return false; |
| 639 | |
| 640 | if ((vgadev->owns & VGA_RSRC_LEGACY_MASK) == VGA_RSRC_LEGACY_MASK) |
| 641 | return true; |
| 642 | |
Huacai Chen | e96902e | 2022-02-24 16:47:48 -0600 | [diff] [blame] | 643 | /* |
| 644 | * If we haven't found a legacy VGA device, accept a non-legacy |
| 645 | * device. It may have either IO or MEM enabled, and bridges may |
| 646 | * not have PCI_BRIDGE_CTL_VGA enabled, so it may not be able to |
| 647 | * use legacy VGA resources. Prefer an integrated GPU over others. |
| 648 | */ |
| 649 | pci_read_config_word(pdev, PCI_COMMAND, &cmd); |
| 650 | if (cmd & (PCI_COMMAND_IO | PCI_COMMAND_MEMORY)) { |
| 651 | |
| 652 | /* |
| 653 | * An integrated GPU overrides a previous non-legacy |
| 654 | * device. We expect only a single integrated GPU, but if |
| 655 | * there are more, we use the *last* because that was the |
| 656 | * previous behavior. |
| 657 | */ |
| 658 | if (vga_arb_integrated_gpu(&pdev->dev)) |
| 659 | return true; |
| 660 | |
| 661 | /* |
| 662 | * We prefer the first non-legacy discrete device we find. |
| 663 | * If we already found one, vgadev is no better. |
| 664 | */ |
| 665 | if (boot_vga) { |
| 666 | pci_read_config_word(boot_vga->pdev, PCI_COMMAND, |
| 667 | &boot_cmd); |
| 668 | if (boot_cmd & (PCI_COMMAND_IO | PCI_COMMAND_MEMORY)) |
| 669 | return false; |
| 670 | } |
| 671 | return true; |
| 672 | } |
| 673 | |
Huacai Chen | 37114e4 | 2022-02-24 16:47:49 -0600 | [diff] [blame] | 674 | /* |
| 675 | * vgadev has neither IO nor MEM enabled. If we haven't found any |
| 676 | * other VGA devices, it is the best candidate so far. |
| 677 | */ |
| 678 | if (!boot_vga) |
| 679 | return true; |
| 680 | |
Huacai Chen | dfe3da8 | 2022-02-24 16:47:46 -0600 | [diff] [blame] | 681 | return false; |
| 682 | } |
| 683 | |
| 684 | /* |
Thierry Reding | 5d90ccf | 2015-08-12 16:32:07 +0200 | [diff] [blame] | 685 | * Rules for using a bridge to control a VGA descendant decoding: if a bridge |
| 686 | * has only one VGA descendant then it can be used to control the VGA routing |
| 687 | * for that device. It should always use the bridge closest to the device to |
| 688 | * control it. If a bridge has a direct VGA descendant, but also have a sub- |
| 689 | * bridge VGA descendant then we cannot use that bridge to control the direct |
| 690 | * VGA descendant. So for every device we register, we need to iterate all |
| 691 | * its parent bridges so we can invalidate any devices using them properly. |
| 692 | */ |
Dave Airlie | 3448a19 | 2010-06-01 15:32:24 +1000 | [diff] [blame] | 693 | static void vga_arbiter_check_bridge_sharing(struct vga_device *vgadev) |
| 694 | { |
| 695 | struct vga_device *same_bridge_vgadev; |
| 696 | struct pci_bus *new_bus, *bus; |
| 697 | struct pci_dev *new_bridge, *bridge; |
| 698 | |
| 699 | vgadev->bridge_has_one_vga = true; |
| 700 | |
Huacai Chen | 4e6c918 | 2022-02-24 16:47:51 -0600 | [diff] [blame] | 701 | if (list_empty(&vga_list)) { |
| 702 | vgaarb_info(&vgadev->pdev->dev, "bridge control possible\n"); |
Dave Airlie | 3448a19 | 2010-06-01 15:32:24 +1000 | [diff] [blame] | 703 | return; |
Huacai Chen | 4e6c918 | 2022-02-24 16:47:51 -0600 | [diff] [blame] | 704 | } |
Dave Airlie | 3448a19 | 2010-06-01 15:32:24 +1000 | [diff] [blame] | 705 | |
| 706 | /* okay iterate the new devices bridge hierarachy */ |
| 707 | new_bus = vgadev->pdev->bus; |
| 708 | while (new_bus) { |
| 709 | new_bridge = new_bus->self; |
| 710 | |
Dave Airlie | f625211 | 2011-10-10 09:29:18 +0100 | [diff] [blame] | 711 | /* go through list of devices already registered */ |
| 712 | list_for_each_entry(same_bridge_vgadev, &vga_list, list) { |
| 713 | bus = same_bridge_vgadev->pdev->bus; |
| 714 | bridge = bus->self; |
| 715 | |
| 716 | /* see if the share a bridge with this device */ |
| 717 | if (new_bridge == bridge) { |
Thierry Reding | 5d90ccf | 2015-08-12 16:32:07 +0200 | [diff] [blame] | 718 | /* |
| 719 | * If their direct parent bridge is the same |
| 720 | * as any bridge of this device then it can't |
| 721 | * be used for that device. |
| 722 | */ |
Dave Airlie | f625211 | 2011-10-10 09:29:18 +0100 | [diff] [blame] | 723 | same_bridge_vgadev->bridge_has_one_vga = false; |
| 724 | } |
| 725 | |
Thierry Reding | 5d90ccf | 2015-08-12 16:32:07 +0200 | [diff] [blame] | 726 | /* |
| 727 | * Now iterate the previous devices bridge hierarchy. |
| 728 | * If the new devices parent bridge is in the other |
| 729 | * devices hierarchy then we can't use it to control |
| 730 | * this device |
| 731 | */ |
Dave Airlie | f625211 | 2011-10-10 09:29:18 +0100 | [diff] [blame] | 732 | while (bus) { |
Dave Airlie | 3448a19 | 2010-06-01 15:32:24 +1000 | [diff] [blame] | 733 | bridge = bus->self; |
Thierry Reding | 5d90ccf | 2015-08-12 16:32:07 +0200 | [diff] [blame] | 734 | |
| 735 | if (bridge && bridge == vgadev->pdev->bus->self) |
| 736 | vgadev->bridge_has_one_vga = false; |
| 737 | |
Dave Airlie | f625211 | 2011-10-10 09:29:18 +0100 | [diff] [blame] | 738 | bus = bus->parent; |
Dave Airlie | 3448a19 | 2010-06-01 15:32:24 +1000 | [diff] [blame] | 739 | } |
| 740 | } |
| 741 | new_bus = new_bus->parent; |
| 742 | } |
Huacai Chen | 4e6c918 | 2022-02-24 16:47:51 -0600 | [diff] [blame] | 743 | |
| 744 | if (vgadev->bridge_has_one_vga) |
| 745 | vgaarb_info(&vgadev->pdev->dev, "bridge control possible\n"); |
| 746 | else |
| 747 | vgaarb_info(&vgadev->pdev->dev, "no bridge control possible\n"); |
Dave Airlie | 3448a19 | 2010-06-01 15:32:24 +1000 | [diff] [blame] | 748 | } |
| 749 | |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 750 | /* |
| 751 | * Currently, we assume that the "initial" setup of the system is |
| 752 | * not sane, that is we come up with conflicting devices and let |
| 753 | * the arbiter's client decides if devices decodes or not legacy |
| 754 | * things. |
| 755 | */ |
| 756 | static bool vga_arbiter_add_pci_device(struct pci_dev *pdev) |
| 757 | { |
| 758 | struct vga_device *vgadev; |
| 759 | unsigned long flags; |
| 760 | struct pci_bus *bus; |
| 761 | struct pci_dev *bridge; |
| 762 | u16 cmd; |
| 763 | |
| 764 | /* Only deal with VGA class devices */ |
| 765 | if ((pdev->class >> 8) != PCI_CLASS_DISPLAY_VGA) |
| 766 | return false; |
| 767 | |
| 768 | /* Allocate structure */ |
Rasmus Villemoes | 945ef5b | 2015-09-30 21:57:06 +0200 | [diff] [blame] | 769 | vgadev = kzalloc(sizeof(struct vga_device), GFP_KERNEL); |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 770 | if (vgadev == NULL) { |
Bjorn Helgaas | a75d68f | 2016-11-17 11:47:58 -0600 | [diff] [blame] | 771 | vgaarb_err(&pdev->dev, "failed to allocate VGA arbiter data\n"); |
Thierry Reding | 5d90ccf | 2015-08-12 16:32:07 +0200 | [diff] [blame] | 772 | /* |
| 773 | * What to do on allocation failure ? For now, let's just do |
| 774 | * nothing, I'm not sure there is anything saner to be done. |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 775 | */ |
| 776 | return false; |
| 777 | } |
| 778 | |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 779 | /* Take lock & check for duplicates */ |
| 780 | spin_lock_irqsave(&vga_lock, flags); |
| 781 | if (vgadev_find(pdev) != NULL) { |
| 782 | BUG_ON(1); |
| 783 | goto fail; |
| 784 | } |
| 785 | vgadev->pdev = pdev; |
| 786 | |
| 787 | /* By default, assume we decode everything */ |
| 788 | vgadev->decodes = VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM | |
| 789 | VGA_RSRC_NORMAL_IO | VGA_RSRC_NORMAL_MEM; |
| 790 | |
| 791 | /* by default mark it as decoding */ |
| 792 | vga_decode_count++; |
| 793 | /* Mark that we "own" resources based on our enables, we will |
| 794 | * clear that below if the bridge isn't forwarding |
| 795 | */ |
| 796 | pci_read_config_word(pdev, PCI_COMMAND, &cmd); |
| 797 | if (cmd & PCI_COMMAND_IO) |
| 798 | vgadev->owns |= VGA_RSRC_LEGACY_IO; |
| 799 | if (cmd & PCI_COMMAND_MEMORY) |
| 800 | vgadev->owns |= VGA_RSRC_LEGACY_MEM; |
| 801 | |
| 802 | /* Check if VGA cycles can get down to us */ |
| 803 | bus = pdev->bus; |
| 804 | while (bus) { |
| 805 | bridge = bus->self; |
| 806 | if (bridge) { |
| 807 | u16 l; |
Thierry Reding | 5d90ccf | 2015-08-12 16:32:07 +0200 | [diff] [blame] | 808 | |
| 809 | pci_read_config_word(bridge, PCI_BRIDGE_CONTROL, &l); |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 810 | if (!(l & PCI_BRIDGE_CTL_VGA)) { |
| 811 | vgadev->owns = 0; |
| 812 | break; |
| 813 | } |
| 814 | } |
| 815 | bus = bus->parent; |
| 816 | } |
| 817 | |
Huacai Chen | dfe3da8 | 2022-02-24 16:47:46 -0600 | [diff] [blame] | 818 | if (vga_is_boot_device(vgadev)) { |
| 819 | vgaarb_info(&pdev->dev, "setting as boot VGA device%s\n", |
| 820 | vga_default_device() ? |
| 821 | " (overriding previous)" : ""); |
Yinghai Lu | 84544a1 | 2012-09-19 11:54:15 -0700 | [diff] [blame] | 822 | vga_set_default_device(pdev); |
Bruno Prémont | 86fd887 | 2014-08-24 23:09:53 +0200 | [diff] [blame] | 823 | } |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 824 | |
Dave Airlie | 3448a19 | 2010-06-01 15:32:24 +1000 | [diff] [blame] | 825 | vga_arbiter_check_bridge_sharing(vgadev); |
| 826 | |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 827 | /* Add to the list */ |
Aaron Ma | 3d42f1d | 2018-09-01 02:20:00 +0800 | [diff] [blame] | 828 | list_add_tail(&vgadev->list, &vga_list); |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 829 | vga_count++; |
Bjorn Helgaas | a75d68f | 2016-11-17 11:47:58 -0600 | [diff] [blame] | 830 | vgaarb_info(&pdev->dev, "VGA device added: decodes=%s,owns=%s,locks=%s\n", |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 831 | vga_iostate_to_str(vgadev->decodes), |
| 832 | vga_iostate_to_str(vgadev->owns), |
| 833 | vga_iostate_to_str(vgadev->locks)); |
| 834 | |
| 835 | spin_unlock_irqrestore(&vga_lock, flags); |
| 836 | return true; |
| 837 | fail: |
| 838 | spin_unlock_irqrestore(&vga_lock, flags); |
| 839 | kfree(vgadev); |
| 840 | return false; |
| 841 | } |
| 842 | |
| 843 | static bool vga_arbiter_del_pci_device(struct pci_dev *pdev) |
| 844 | { |
| 845 | struct vga_device *vgadev; |
| 846 | unsigned long flags; |
| 847 | bool ret = true; |
| 848 | |
| 849 | spin_lock_irqsave(&vga_lock, flags); |
| 850 | vgadev = vgadev_find(pdev); |
| 851 | if (vgadev == NULL) { |
| 852 | ret = false; |
| 853 | goto bail; |
| 854 | } |
| 855 | |
Yinghai Lu | 84544a1 | 2012-09-19 11:54:15 -0700 | [diff] [blame] | 856 | if (vga_default == pdev) |
| 857 | vga_set_default_device(NULL); |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 858 | |
| 859 | if (vgadev->decodes & (VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM)) |
| 860 | vga_decode_count--; |
| 861 | |
| 862 | /* Remove entry from list */ |
| 863 | list_del(&vgadev->list); |
| 864 | vga_count--; |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 865 | |
| 866 | /* Wake up all possible waiters */ |
| 867 | wake_up_all(&vga_wait_queue); |
| 868 | bail: |
| 869 | spin_unlock_irqrestore(&vga_lock, flags); |
| 870 | kfree(vgadev); |
| 871 | return ret; |
| 872 | } |
| 873 | |
| 874 | /* this is called with the lock */ |
| 875 | static inline void vga_update_device_decodes(struct vga_device *vgadev, |
| 876 | int new_decodes) |
| 877 | { |
Bjorn Helgaas | a75d68f | 2016-11-17 11:47:58 -0600 | [diff] [blame] | 878 | struct device *dev = &vgadev->pdev->dev; |
Alex Williamson | 5c0f6ee | 2013-08-15 16:37:59 -0600 | [diff] [blame] | 879 | int old_decodes, decodes_removed, decodes_unlocked; |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 880 | |
| 881 | old_decodes = vgadev->decodes; |
Alex Williamson | 5c0f6ee | 2013-08-15 16:37:59 -0600 | [diff] [blame] | 882 | decodes_removed = ~new_decodes & old_decodes; |
| 883 | decodes_unlocked = vgadev->locks & decodes_removed; |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 884 | vgadev->decodes = new_decodes; |
| 885 | |
Bjorn Helgaas | a75d68f | 2016-11-17 11:47:58 -0600 | [diff] [blame] | 886 | vgaarb_info(dev, "changed VGA decodes: olddecodes=%s,decodes=%s:owns=%s\n", |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 887 | vga_iostate_to_str(old_decodes), |
| 888 | vga_iostate_to_str(vgadev->decodes), |
| 889 | vga_iostate_to_str(vgadev->owns)); |
| 890 | |
Alex Williamson | 5c0f6ee | 2013-08-15 16:37:59 -0600 | [diff] [blame] | 891 | /* if we removed locked decodes, lock count goes to zero, and release */ |
| 892 | if (decodes_unlocked) { |
| 893 | if (decodes_unlocked & VGA_RSRC_LEGACY_IO) |
| 894 | vgadev->io_lock_cnt = 0; |
| 895 | if (decodes_unlocked & VGA_RSRC_LEGACY_MEM) |
| 896 | vgadev->mem_lock_cnt = 0; |
| 897 | __vga_put(vgadev, decodes_unlocked); |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 898 | } |
| 899 | |
| 900 | /* change decodes counter */ |
Alex Williamson | 5c0f6ee | 2013-08-15 16:37:59 -0600 | [diff] [blame] | 901 | if (old_decodes & VGA_RSRC_LEGACY_MASK && |
| 902 | !(new_decodes & VGA_RSRC_LEGACY_MASK)) |
| 903 | vga_decode_count--; |
| 904 | if (!(old_decodes & VGA_RSRC_LEGACY_MASK) && |
| 905 | new_decodes & VGA_RSRC_LEGACY_MASK) |
| 906 | vga_decode_count++; |
Bjorn Helgaas | a75d68f | 2016-11-17 11:47:58 -0600 | [diff] [blame] | 907 | vgaarb_dbg(dev, "decoding count now is: %d\n", vga_decode_count); |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 908 | } |
| 909 | |
Thierry Reding | 5d90ccf | 2015-08-12 16:32:07 +0200 | [diff] [blame] | 910 | static void __vga_set_legacy_decoding(struct pci_dev *pdev, |
| 911 | unsigned int decodes, |
| 912 | bool userspace) |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 913 | { |
| 914 | struct vga_device *vgadev; |
| 915 | unsigned long flags; |
| 916 | |
| 917 | decodes &= VGA_RSRC_LEGACY_MASK; |
| 918 | |
| 919 | spin_lock_irqsave(&vga_lock, flags); |
| 920 | vgadev = vgadev_find(pdev); |
| 921 | if (vgadev == NULL) |
| 922 | goto bail; |
| 923 | |
| 924 | /* don't let userspace futz with kernel driver decodes */ |
Christoph Hellwig | bf44e8c | 2021-07-16 08:16:34 +0200 | [diff] [blame] | 925 | if (userspace && vgadev->set_decode) |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 926 | goto bail; |
| 927 | |
| 928 | /* update the device decodes + counter */ |
| 929 | vga_update_device_decodes(vgadev, decodes); |
| 930 | |
| 931 | /* XXX if somebody is going from "doesn't decode" to "decodes" state |
| 932 | * here, additional care must be taken as we may have pending owner |
| 933 | * ship of non-legacy region ... |
| 934 | */ |
| 935 | bail: |
| 936 | spin_unlock_irqrestore(&vga_lock, flags); |
| 937 | } |
| 938 | |
Christoph Hellwig | 45549c0 | 2021-07-16 08:16:30 +0200 | [diff] [blame] | 939 | /** |
| 940 | * vga_set_legacy_decoding |
| 941 | * @pdev: pci device of the VGA card |
| 942 | * @decodes: bit mask of what legacy regions the card decodes |
| 943 | * |
| 944 | * Indicates to the arbiter if the card decodes legacy VGA IOs, legacy VGA |
| 945 | * Memory, both, or none. All cards default to both, the card driver (fbdev for |
| 946 | * example) should tell the arbiter if it has disabled legacy decoding, so the |
| 947 | * card can be left out of the arbitration process (and can be safe to take |
| 948 | * interrupts at any time. |
| 949 | */ |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 950 | void vga_set_legacy_decoding(struct pci_dev *pdev, unsigned int decodes) |
| 951 | { |
| 952 | __vga_set_legacy_decoding(pdev, decodes, false); |
| 953 | } |
| 954 | EXPORT_SYMBOL(vga_set_legacy_decoding); |
| 955 | |
Daniel Vetter | b754b35 | 2016-08-12 22:48:56 +0200 | [diff] [blame] | 956 | /** |
| 957 | * vga_client_register - register or unregister a VGA arbitration client |
| 958 | * @pdev: pci device of the VGA client |
Christoph Hellwig | bf44e8c | 2021-07-16 08:16:34 +0200 | [diff] [blame] | 959 | * @set_decode: vga decode change callback |
Daniel Vetter | b754b35 | 2016-08-12 22:48:56 +0200 | [diff] [blame] | 960 | * |
| 961 | * Clients have two callback mechanisms they can use. |
| 962 | * |
Christoph Hellwig | bf44e8c | 2021-07-16 08:16:34 +0200 | [diff] [blame] | 963 | * @set_decode callback: If a client can disable its GPU VGA resource, it |
Daniel Vetter | b754b35 | 2016-08-12 22:48:56 +0200 | [diff] [blame] | 964 | * will get a callback from this to set the encode/decode state. |
| 965 | * |
| 966 | * Rationale: we cannot disable VGA decode resources unconditionally some single |
| 967 | * GPU laptops seem to require ACPI or BIOS access to the VGA registers to |
| 968 | * control things like backlights etc. Hopefully newer multi-GPU laptops do |
| 969 | * something saner, and desktops won't have any special ACPI for this. The |
| 970 | * driver will get a callback when VGA arbitration is first used by userspace |
| 971 | * since some older X servers have issues. |
| 972 | * |
| 973 | * This function does not check whether a client for @pdev has been registered |
| 974 | * already. |
| 975 | * |
Christoph Hellwig | b877947 | 2021-07-16 08:16:32 +0200 | [diff] [blame] | 976 | * To unregister just call vga_client_unregister(). |
Daniel Vetter | b754b35 | 2016-08-12 22:48:56 +0200 | [diff] [blame] | 977 | * |
| 978 | * Returns: 0 on success, -1 on failure |
| 979 | */ |
Christoph Hellwig | bf44e8c | 2021-07-16 08:16:34 +0200 | [diff] [blame] | 980 | int vga_client_register(struct pci_dev *pdev, |
| 981 | unsigned int (*set_decode)(struct pci_dev *pdev, bool decode)) |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 982 | { |
Chris Wilson | 934f992c | 2011-01-20 13:09:12 +0000 | [diff] [blame] | 983 | int ret = -ENODEV; |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 984 | struct vga_device *vgadev; |
| 985 | unsigned long flags; |
| 986 | |
| 987 | spin_lock_irqsave(&vga_lock, flags); |
| 988 | vgadev = vgadev_find(pdev); |
| 989 | if (!vgadev) |
| 990 | goto bail; |
| 991 | |
Christoph Hellwig | bf44e8c | 2021-07-16 08:16:34 +0200 | [diff] [blame] | 992 | vgadev->set_decode = set_decode; |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 993 | ret = 0; |
| 994 | |
| 995 | bail: |
| 996 | spin_unlock_irqrestore(&vga_lock, flags); |
| 997 | return ret; |
| 998 | |
| 999 | } |
| 1000 | EXPORT_SYMBOL(vga_client_register); |
| 1001 | |
| 1002 | /* |
| 1003 | * Char driver implementation |
| 1004 | * |
| 1005 | * Semantics is: |
| 1006 | * |
| 1007 | * open : open user instance of the arbitrer. by default, it's |
| 1008 | * attached to the default VGA device of the system. |
| 1009 | * |
| 1010 | * close : close user instance, release locks |
| 1011 | * |
| 1012 | * read : return a string indicating the status of the target. |
| 1013 | * an IO state string is of the form {io,mem,io+mem,none}, |
| 1014 | * mc and ic are respectively mem and io lock counts (for |
| 1015 | * debugging/diagnostic only). "decodes" indicate what the |
| 1016 | * card currently decodes, "owns" indicates what is currently |
| 1017 | * enabled on it, and "locks" indicates what is locked by this |
| 1018 | * card. If the card is unplugged, we get "invalid" then for |
| 1019 | * card_ID and an -ENODEV error is returned for any command |
| 1020 | * until a new card is targeted |
| 1021 | * |
| 1022 | * "<card_ID>,decodes=<io_state>,owns=<io_state>,locks=<io_state> (ic,mc)" |
| 1023 | * |
| 1024 | * write : write a command to the arbiter. List of commands is: |
| 1025 | * |
| 1026 | * target <card_ID> : switch target to card <card_ID> (see below) |
| 1027 | * lock <io_state> : acquires locks on target ("none" is invalid io_state) |
| 1028 | * trylock <io_state> : non-blocking acquire locks on target |
| 1029 | * unlock <io_state> : release locks on target |
| 1030 | * unlock all : release all locks on target held by this user |
| 1031 | * decodes <io_state> : set the legacy decoding attributes for the card |
| 1032 | * |
| 1033 | * poll : event if something change on any card (not just the target) |
| 1034 | * |
| 1035 | * card_ID is of the form "PCI:domain:bus:dev.fn". It can be set to "default" |
| 1036 | * to go back to the system default card (TODO: not implemented yet). |
| 1037 | * Currently, only PCI is supported as a prefix, but the userland API may |
| 1038 | * support other bus types in the future, even if the current kernel |
| 1039 | * implementation doesn't. |
| 1040 | * |
| 1041 | * Note about locks: |
| 1042 | * |
| 1043 | * The driver keeps track of which user has what locks on which card. It |
| 1044 | * supports stacking, like the kernel one. This complexifies the implementation |
| 1045 | * a bit, but makes the arbiter more tolerant to userspace problems and able |
| 1046 | * to properly cleanup in all cases when a process dies. |
| 1047 | * Currently, a max of 16 cards simultaneously can have locks issued from |
| 1048 | * userspace for a given user (file descriptor instance) of the arbiter. |
| 1049 | * |
| 1050 | * If the device is hot-unplugged, there is a hook inside the module to notify |
| 1051 | * they being added/removed in the system and automatically added/removed in |
| 1052 | * the arbiter. |
| 1053 | */ |
| 1054 | |
Mike Travis | 36028f3 | 2010-02-02 17:45:01 -0800 | [diff] [blame] | 1055 | #define MAX_USER_CARDS CONFIG_VGA_ARB_MAX_GPUS |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 1056 | #define PCI_INVALID_CARD ((struct pci_dev *)-1UL) |
| 1057 | |
| 1058 | /* |
| 1059 | * Each user has an array of these, tracking which cards have locks |
| 1060 | */ |
| 1061 | struct vga_arb_user_card { |
| 1062 | struct pci_dev *pdev; |
| 1063 | unsigned int mem_cnt; |
| 1064 | unsigned int io_cnt; |
| 1065 | }; |
| 1066 | |
| 1067 | struct vga_arb_private { |
| 1068 | struct list_head list; |
| 1069 | struct pci_dev *target; |
| 1070 | struct vga_arb_user_card cards[MAX_USER_CARDS]; |
| 1071 | spinlock_t lock; |
| 1072 | }; |
| 1073 | |
| 1074 | static LIST_HEAD(vga_user_list); |
| 1075 | static DEFINE_SPINLOCK(vga_user_lock); |
| 1076 | |
| 1077 | |
| 1078 | /* |
| 1079 | * This function gets a string in the format: "PCI:domain:bus:dev.fn" and |
| 1080 | * returns the respective values. If the string is not in this format, |
| 1081 | * it returns 0. |
| 1082 | */ |
| 1083 | static int vga_pci_str_to_vars(char *buf, int count, unsigned int *domain, |
| 1084 | unsigned int *bus, unsigned int *devfn) |
| 1085 | { |
| 1086 | int n; |
| 1087 | unsigned int slot, func; |
| 1088 | |
| 1089 | |
| 1090 | n = sscanf(buf, "PCI:%x:%x:%x.%x", domain, bus, &slot, &func); |
| 1091 | if (n != 4) |
| 1092 | return 0; |
| 1093 | |
| 1094 | *devfn = PCI_DEVFN(slot, func); |
| 1095 | |
| 1096 | return 1; |
| 1097 | } |
| 1098 | |
Thierry Reding | 5d90ccf | 2015-08-12 16:32:07 +0200 | [diff] [blame] | 1099 | static ssize_t vga_arb_read(struct file *file, char __user *buf, |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 1100 | size_t count, loff_t *ppos) |
| 1101 | { |
| 1102 | struct vga_arb_private *priv = file->private_data; |
| 1103 | struct vga_device *vgadev; |
| 1104 | struct pci_dev *pdev; |
| 1105 | unsigned long flags; |
| 1106 | size_t len; |
| 1107 | int rc; |
| 1108 | char *lbuf; |
| 1109 | |
| 1110 | lbuf = kmalloc(1024, GFP_KERNEL); |
| 1111 | if (lbuf == NULL) |
| 1112 | return -ENOMEM; |
| 1113 | |
Bjorn Helgaas | dc593fd | 2022-02-24 16:47:50 -0600 | [diff] [blame] | 1114 | /* Protects vga_list */ |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 1115 | spin_lock_irqsave(&vga_lock, flags); |
| 1116 | |
Lucas De Marchi | 25985ed | 2011-03-30 22:57:33 -0300 | [diff] [blame] | 1117 | /* If we are targeting the default, use it */ |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 1118 | pdev = priv->target; |
| 1119 | if (pdev == NULL || pdev == PCI_INVALID_CARD) { |
| 1120 | spin_unlock_irqrestore(&vga_lock, flags); |
| 1121 | len = sprintf(lbuf, "invalid"); |
| 1122 | goto done; |
| 1123 | } |
| 1124 | |
| 1125 | /* Find card vgadev structure */ |
| 1126 | vgadev = vgadev_find(pdev); |
| 1127 | if (vgadev == NULL) { |
| 1128 | /* Wow, it's not in the list, that shouldn't happen, |
| 1129 | * let's fix us up and return invalid card |
| 1130 | */ |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 1131 | spin_unlock_irqrestore(&vga_lock, flags); |
| 1132 | len = sprintf(lbuf, "invalid"); |
| 1133 | goto done; |
| 1134 | } |
| 1135 | |
| 1136 | /* Fill the buffer with infos */ |
| 1137 | len = snprintf(lbuf, 1024, |
Bjorn Helgaas | d5109fe | 2022-02-24 16:47:52 -0600 | [diff] [blame] | 1138 | "count:%d,PCI:%s,decodes=%s,owns=%s,locks=%s(%u:%u)\n", |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 1139 | vga_decode_count, pci_name(pdev), |
| 1140 | vga_iostate_to_str(vgadev->decodes), |
| 1141 | vga_iostate_to_str(vgadev->owns), |
| 1142 | vga_iostate_to_str(vgadev->locks), |
| 1143 | vgadev->io_lock_cnt, vgadev->mem_lock_cnt); |
| 1144 | |
| 1145 | spin_unlock_irqrestore(&vga_lock, flags); |
| 1146 | done: |
| 1147 | |
| 1148 | /* Copy that to user */ |
| 1149 | if (len > count) |
| 1150 | len = count; |
| 1151 | rc = copy_to_user(buf, lbuf, len); |
| 1152 | kfree(lbuf); |
| 1153 | if (rc) |
| 1154 | return -EFAULT; |
| 1155 | return len; |
| 1156 | } |
| 1157 | |
| 1158 | /* |
| 1159 | * TODO: To avoid parsing inside kernel and to improve the speed we may |
| 1160 | * consider use ioctl here |
| 1161 | */ |
Thierry Reding | 5d90ccf | 2015-08-12 16:32:07 +0200 | [diff] [blame] | 1162 | static ssize_t vga_arb_write(struct file *file, const char __user *buf, |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 1163 | size_t count, loff_t *ppos) |
| 1164 | { |
| 1165 | struct vga_arb_private *priv = file->private_data; |
| 1166 | struct vga_arb_user_card *uc = NULL; |
| 1167 | struct pci_dev *pdev; |
| 1168 | |
| 1169 | unsigned int io_state; |
| 1170 | |
Dmitry Vyukov | 49521b1 | 2016-10-14 15:22:22 +0200 | [diff] [blame] | 1171 | char kbuf[64], *curr_pos; |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 1172 | size_t remaining = count; |
| 1173 | |
| 1174 | int ret_val; |
| 1175 | int i; |
| 1176 | |
Dmitry Vyukov | 49521b1 | 2016-10-14 15:22:22 +0200 | [diff] [blame] | 1177 | if (count >= sizeof(kbuf)) |
| 1178 | return -EINVAL; |
| 1179 | if (copy_from_user(kbuf, buf, count)) |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 1180 | return -EFAULT; |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 1181 | curr_pos = kbuf; |
| 1182 | kbuf[count] = '\0'; /* Just to make sure... */ |
| 1183 | |
| 1184 | if (strncmp(curr_pos, "lock ", 5) == 0) { |
| 1185 | curr_pos += 5; |
| 1186 | remaining -= 5; |
| 1187 | |
Tiago Vignatti | 2d6e9b9 | 2010-05-24 18:24:30 +0300 | [diff] [blame] | 1188 | pr_debug("client 0x%p called 'lock'\n", priv); |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 1189 | |
| 1190 | if (!vga_str_to_iostate(curr_pos, remaining, &io_state)) { |
| 1191 | ret_val = -EPROTO; |
| 1192 | goto done; |
| 1193 | } |
| 1194 | if (io_state == VGA_RSRC_NONE) { |
| 1195 | ret_val = -EPROTO; |
| 1196 | goto done; |
| 1197 | } |
| 1198 | |
| 1199 | pdev = priv->target; |
| 1200 | if (priv->target == NULL) { |
| 1201 | ret_val = -ENODEV; |
| 1202 | goto done; |
| 1203 | } |
| 1204 | |
| 1205 | vga_get_uninterruptible(pdev, io_state); |
| 1206 | |
| 1207 | /* Update the client's locks lists... */ |
| 1208 | for (i = 0; i < MAX_USER_CARDS; i++) { |
| 1209 | if (priv->cards[i].pdev == pdev) { |
| 1210 | if (io_state & VGA_RSRC_LEGACY_IO) |
| 1211 | priv->cards[i].io_cnt++; |
| 1212 | if (io_state & VGA_RSRC_LEGACY_MEM) |
| 1213 | priv->cards[i].mem_cnt++; |
| 1214 | break; |
| 1215 | } |
| 1216 | } |
| 1217 | |
| 1218 | ret_val = count; |
| 1219 | goto done; |
| 1220 | } else if (strncmp(curr_pos, "unlock ", 7) == 0) { |
| 1221 | curr_pos += 7; |
| 1222 | remaining -= 7; |
| 1223 | |
Tiago Vignatti | 2d6e9b9 | 2010-05-24 18:24:30 +0300 | [diff] [blame] | 1224 | pr_debug("client 0x%p called 'unlock'\n", priv); |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 1225 | |
| 1226 | if (strncmp(curr_pos, "all", 3) == 0) |
| 1227 | io_state = VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM; |
| 1228 | else { |
| 1229 | if (!vga_str_to_iostate |
| 1230 | (curr_pos, remaining, &io_state)) { |
| 1231 | ret_val = -EPROTO; |
| 1232 | goto done; |
| 1233 | } |
| 1234 | /* TODO: Add this? |
| 1235 | if (io_state == VGA_RSRC_NONE) { |
| 1236 | ret_val = -EPROTO; |
| 1237 | goto done; |
| 1238 | } |
| 1239 | */ |
| 1240 | } |
| 1241 | |
| 1242 | pdev = priv->target; |
| 1243 | if (priv->target == NULL) { |
| 1244 | ret_val = -ENODEV; |
| 1245 | goto done; |
| 1246 | } |
| 1247 | for (i = 0; i < MAX_USER_CARDS; i++) { |
| 1248 | if (priv->cards[i].pdev == pdev) |
| 1249 | uc = &priv->cards[i]; |
| 1250 | } |
| 1251 | |
Julia Lawall | c916874 | 2011-11-15 14:53:11 -0800 | [diff] [blame] | 1252 | if (!uc) { |
| 1253 | ret_val = -EINVAL; |
| 1254 | goto done; |
| 1255 | } |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 1256 | |
Julia Lawall | c916874 | 2011-11-15 14:53:11 -0800 | [diff] [blame] | 1257 | if (io_state & VGA_RSRC_LEGACY_IO && uc->io_cnt == 0) { |
| 1258 | ret_val = -EINVAL; |
| 1259 | goto done; |
| 1260 | } |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 1261 | |
Julia Lawall | c916874 | 2011-11-15 14:53:11 -0800 | [diff] [blame] | 1262 | if (io_state & VGA_RSRC_LEGACY_MEM && uc->mem_cnt == 0) { |
| 1263 | ret_val = -EINVAL; |
| 1264 | goto done; |
| 1265 | } |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 1266 | |
| 1267 | vga_put(pdev, io_state); |
| 1268 | |
| 1269 | if (io_state & VGA_RSRC_LEGACY_IO) |
| 1270 | uc->io_cnt--; |
| 1271 | if (io_state & VGA_RSRC_LEGACY_MEM) |
| 1272 | uc->mem_cnt--; |
| 1273 | |
| 1274 | ret_val = count; |
| 1275 | goto done; |
| 1276 | } else if (strncmp(curr_pos, "trylock ", 8) == 0) { |
| 1277 | curr_pos += 8; |
| 1278 | remaining -= 8; |
| 1279 | |
Tiago Vignatti | 2d6e9b9 | 2010-05-24 18:24:30 +0300 | [diff] [blame] | 1280 | pr_debug("client 0x%p called 'trylock'\n", priv); |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 1281 | |
| 1282 | if (!vga_str_to_iostate(curr_pos, remaining, &io_state)) { |
| 1283 | ret_val = -EPROTO; |
| 1284 | goto done; |
| 1285 | } |
| 1286 | /* TODO: Add this? |
| 1287 | if (io_state == VGA_RSRC_NONE) { |
| 1288 | ret_val = -EPROTO; |
| 1289 | goto done; |
| 1290 | } |
| 1291 | */ |
| 1292 | |
| 1293 | pdev = priv->target; |
| 1294 | if (priv->target == NULL) { |
| 1295 | ret_val = -ENODEV; |
| 1296 | goto done; |
| 1297 | } |
| 1298 | |
| 1299 | if (vga_tryget(pdev, io_state)) { |
| 1300 | /* Update the client's locks lists... */ |
| 1301 | for (i = 0; i < MAX_USER_CARDS; i++) { |
| 1302 | if (priv->cards[i].pdev == pdev) { |
| 1303 | if (io_state & VGA_RSRC_LEGACY_IO) |
| 1304 | priv->cards[i].io_cnt++; |
| 1305 | if (io_state & VGA_RSRC_LEGACY_MEM) |
| 1306 | priv->cards[i].mem_cnt++; |
| 1307 | break; |
| 1308 | } |
| 1309 | } |
| 1310 | ret_val = count; |
| 1311 | goto done; |
| 1312 | } else { |
| 1313 | ret_val = -EBUSY; |
| 1314 | goto done; |
| 1315 | } |
| 1316 | |
| 1317 | } else if (strncmp(curr_pos, "target ", 7) == 0) { |
| 1318 | unsigned int domain, bus, devfn; |
| 1319 | struct vga_device *vgadev; |
| 1320 | |
| 1321 | curr_pos += 7; |
| 1322 | remaining -= 7; |
Tiago Vignatti | 2d6e9b9 | 2010-05-24 18:24:30 +0300 | [diff] [blame] | 1323 | pr_debug("client 0x%p called 'target'\n", priv); |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 1324 | /* if target is default */ |
Kyle McMartin | 2cc9116 | 2010-02-16 16:18:37 -0500 | [diff] [blame] | 1325 | if (!strncmp(curr_pos, "default", 7)) |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 1326 | pdev = pci_dev_get(vga_default_device()); |
| 1327 | else { |
| 1328 | if (!vga_pci_str_to_vars(curr_pos, remaining, |
| 1329 | &domain, &bus, &devfn)) { |
| 1330 | ret_val = -EPROTO; |
| 1331 | goto done; |
| 1332 | } |
Jiang Liu | f85567c | 2012-08-28 23:43:55 +0800 | [diff] [blame] | 1333 | pdev = pci_get_domain_bus_and_slot(domain, bus, devfn); |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 1334 | if (!pdev) { |
Bjorn Helgaas | cf590b8 | 2016-11-18 08:11:58 -0600 | [diff] [blame] | 1335 | pr_debug("invalid PCI address %04x:%02x:%02x.%x\n", |
| 1336 | domain, bus, PCI_SLOT(devfn), |
| 1337 | PCI_FUNC(devfn)); |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 1338 | ret_val = -ENODEV; |
| 1339 | goto done; |
| 1340 | } |
Bjorn Helgaas | a75d68f | 2016-11-17 11:47:58 -0600 | [diff] [blame] | 1341 | |
| 1342 | pr_debug("%s ==> %04x:%02x:%02x.%x pdev %p\n", curr_pos, |
| 1343 | domain, bus, PCI_SLOT(devfn), PCI_FUNC(devfn), |
| 1344 | pdev); |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 1345 | } |
| 1346 | |
| 1347 | vgadev = vgadev_find(pdev); |
Thierry Reding | 8b7e2e8 | 2015-08-12 16:32:06 +0200 | [diff] [blame] | 1348 | pr_debug("vgadev %p\n", vgadev); |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 1349 | if (vgadev == NULL) { |
Thierry Reding | eb6944f | 2015-08-12 16:32:05 +0200 | [diff] [blame] | 1350 | if (pdev) { |
Bjorn Helgaas | cf590b8 | 2016-11-18 08:11:58 -0600 | [diff] [blame] | 1351 | vgaarb_dbg(&pdev->dev, "not a VGA device\n"); |
Thierry Reding | eb6944f | 2015-08-12 16:32:05 +0200 | [diff] [blame] | 1352 | pci_dev_put(pdev); |
| 1353 | } |
| 1354 | |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 1355 | ret_val = -ENODEV; |
| 1356 | goto done; |
| 1357 | } |
| 1358 | |
| 1359 | priv->target = pdev; |
| 1360 | for (i = 0; i < MAX_USER_CARDS; i++) { |
| 1361 | if (priv->cards[i].pdev == pdev) |
| 1362 | break; |
| 1363 | if (priv->cards[i].pdev == NULL) { |
| 1364 | priv->cards[i].pdev = pdev; |
| 1365 | priv->cards[i].io_cnt = 0; |
| 1366 | priv->cards[i].mem_cnt = 0; |
| 1367 | break; |
| 1368 | } |
| 1369 | } |
| 1370 | if (i == MAX_USER_CARDS) { |
Bjorn Helgaas | cf590b8 | 2016-11-18 08:11:58 -0600 | [diff] [blame] | 1371 | vgaarb_dbg(&pdev->dev, "maximum user cards (%d) number reached, ignoring this one!\n", |
Mike Travis | 773a38db | 2010-02-02 14:38:15 -0800 | [diff] [blame] | 1372 | MAX_USER_CARDS); |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 1373 | pci_dev_put(pdev); |
| 1374 | /* XXX: which value to return? */ |
| 1375 | ret_val = -ENOMEM; |
| 1376 | goto done; |
| 1377 | } |
| 1378 | |
| 1379 | ret_val = count; |
| 1380 | pci_dev_put(pdev); |
| 1381 | goto done; |
| 1382 | |
| 1383 | |
| 1384 | } else if (strncmp(curr_pos, "decodes ", 8) == 0) { |
| 1385 | curr_pos += 8; |
| 1386 | remaining -= 8; |
Thierry Reding | 8b7e2e8 | 2015-08-12 16:32:06 +0200 | [diff] [blame] | 1387 | pr_debug("client 0x%p called 'decodes'\n", priv); |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 1388 | |
| 1389 | if (!vga_str_to_iostate(curr_pos, remaining, &io_state)) { |
| 1390 | ret_val = -EPROTO; |
| 1391 | goto done; |
| 1392 | } |
| 1393 | pdev = priv->target; |
| 1394 | if (priv->target == NULL) { |
| 1395 | ret_val = -ENODEV; |
| 1396 | goto done; |
| 1397 | } |
| 1398 | |
| 1399 | __vga_set_legacy_decoding(pdev, io_state, true); |
| 1400 | ret_val = count; |
| 1401 | goto done; |
| 1402 | } |
| 1403 | /* If we got here, the message written is not part of the protocol! */ |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 1404 | return -EPROTO; |
| 1405 | |
| 1406 | done: |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 1407 | return ret_val; |
| 1408 | } |
| 1409 | |
Al Viro | afc9a42 | 2017-07-03 06:39:46 -0400 | [diff] [blame] | 1410 | static __poll_t vga_arb_fpoll(struct file *file, poll_table *wait) |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 1411 | { |
Tiago Vignatti | 2d6e9b9 | 2010-05-24 18:24:30 +0300 | [diff] [blame] | 1412 | pr_debug("%s\n", __func__); |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 1413 | |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 1414 | poll_wait(file, &vga_wait_queue, wait); |
Linus Torvalds | a9a0884 | 2018-02-11 14:34:03 -0800 | [diff] [blame] | 1415 | return EPOLLIN; |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 1416 | } |
| 1417 | |
| 1418 | static int vga_arb_open(struct inode *inode, struct file *file) |
| 1419 | { |
| 1420 | struct vga_arb_private *priv; |
| 1421 | unsigned long flags; |
| 1422 | |
Tiago Vignatti | 2d6e9b9 | 2010-05-24 18:24:30 +0300 | [diff] [blame] | 1423 | pr_debug("%s\n", __func__); |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 1424 | |
Rakib Mullick | f35119d | 2011-07-25 17:12:56 -0700 | [diff] [blame] | 1425 | priv = kzalloc(sizeof(*priv), GFP_KERNEL); |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 1426 | if (priv == NULL) |
| 1427 | return -ENOMEM; |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 1428 | spin_lock_init(&priv->lock); |
| 1429 | file->private_data = priv; |
| 1430 | |
| 1431 | spin_lock_irqsave(&vga_user_lock, flags); |
| 1432 | list_add(&priv->list, &vga_user_list); |
| 1433 | spin_unlock_irqrestore(&vga_user_lock, flags); |
| 1434 | |
| 1435 | /* Set the client' lists of locks */ |
| 1436 | priv->target = vga_default_device(); /* Maybe this is still null! */ |
| 1437 | priv->cards[0].pdev = priv->target; |
| 1438 | priv->cards[0].io_cnt = 0; |
| 1439 | priv->cards[0].mem_cnt = 0; |
| 1440 | |
| 1441 | |
| 1442 | return 0; |
| 1443 | } |
| 1444 | |
| 1445 | static int vga_arb_release(struct inode *inode, struct file *file) |
| 1446 | { |
| 1447 | struct vga_arb_private *priv = file->private_data; |
| 1448 | struct vga_arb_user_card *uc; |
| 1449 | unsigned long flags; |
| 1450 | int i; |
| 1451 | |
Tiago Vignatti | 2d6e9b9 | 2010-05-24 18:24:30 +0300 | [diff] [blame] | 1452 | pr_debug("%s\n", __func__); |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 1453 | |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 1454 | spin_lock_irqsave(&vga_user_lock, flags); |
| 1455 | list_del(&priv->list); |
| 1456 | for (i = 0; i < MAX_USER_CARDS; i++) { |
| 1457 | uc = &priv->cards[i]; |
| 1458 | if (uc->pdev == NULL) |
| 1459 | continue; |
Bjorn Helgaas | a75d68f | 2016-11-17 11:47:58 -0600 | [diff] [blame] | 1460 | vgaarb_dbg(&uc->pdev->dev, "uc->io_cnt == %d, uc->mem_cnt == %d\n", |
| 1461 | uc->io_cnt, uc->mem_cnt); |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 1462 | while (uc->io_cnt--) |
| 1463 | vga_put(uc->pdev, VGA_RSRC_LEGACY_IO); |
| 1464 | while (uc->mem_cnt--) |
| 1465 | vga_put(uc->pdev, VGA_RSRC_LEGACY_MEM); |
| 1466 | } |
| 1467 | spin_unlock_irqrestore(&vga_user_lock, flags); |
| 1468 | |
| 1469 | kfree(priv); |
| 1470 | |
| 1471 | return 0; |
| 1472 | } |
| 1473 | |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 1474 | /* |
| 1475 | * callback any registered clients to let them know we have a |
| 1476 | * change in VGA cards |
| 1477 | */ |
| 1478 | static void vga_arbiter_notify_clients(void) |
| 1479 | { |
| 1480 | struct vga_device *vgadev; |
| 1481 | unsigned long flags; |
| 1482 | uint32_t new_decodes; |
| 1483 | bool new_state; |
| 1484 | |
| 1485 | if (!vga_arbiter_used) |
| 1486 | return; |
| 1487 | |
| 1488 | spin_lock_irqsave(&vga_lock, flags); |
| 1489 | list_for_each_entry(vgadev, &vga_list, list) { |
| 1490 | if (vga_count > 1) |
| 1491 | new_state = false; |
| 1492 | else |
| 1493 | new_state = true; |
Christoph Hellwig | bf44e8c | 2021-07-16 08:16:34 +0200 | [diff] [blame] | 1494 | if (vgadev->set_decode) { |
| 1495 | new_decodes = vgadev->set_decode(vgadev->pdev, |
| 1496 | new_state); |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 1497 | vga_update_device_decodes(vgadev, new_decodes); |
| 1498 | } |
| 1499 | } |
| 1500 | spin_unlock_irqrestore(&vga_lock, flags); |
| 1501 | } |
| 1502 | |
| 1503 | static int pci_notify(struct notifier_block *nb, unsigned long action, |
| 1504 | void *data) |
| 1505 | { |
| 1506 | struct device *dev = data; |
| 1507 | struct pci_dev *pdev = to_pci_dev(dev); |
| 1508 | bool notify = false; |
| 1509 | |
Bjorn Helgaas | a75d68f | 2016-11-17 11:47:58 -0600 | [diff] [blame] | 1510 | vgaarb_dbg(dev, "%s\n", __func__); |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 1511 | |
| 1512 | /* For now we're only intereted in devices added and removed. I didn't |
| 1513 | * test this thing here, so someone needs to double check for the |
| 1514 | * cases of hotplugable vga cards. */ |
| 1515 | if (action == BUS_NOTIFY_ADD_DEVICE) |
| 1516 | notify = vga_arbiter_add_pci_device(pdev); |
| 1517 | else if (action == BUS_NOTIFY_DEL_DEVICE) |
| 1518 | notify = vga_arbiter_del_pci_device(pdev); |
| 1519 | |
| 1520 | if (notify) |
| 1521 | vga_arbiter_notify_clients(); |
| 1522 | return 0; |
| 1523 | } |
| 1524 | |
| 1525 | static struct notifier_block pci_notifier = { |
| 1526 | .notifier_call = pci_notify, |
| 1527 | }; |
| 1528 | |
| 1529 | static const struct file_operations vga_arb_device_fops = { |
| 1530 | .read = vga_arb_read, |
| 1531 | .write = vga_arb_write, |
| 1532 | .poll = vga_arb_fpoll, |
| 1533 | .open = vga_arb_open, |
| 1534 | .release = vga_arb_release, |
Arnd Bergmann | 6038f37 | 2010-08-15 18:52:59 +0200 | [diff] [blame] | 1535 | .llseek = noop_llseek, |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 1536 | }; |
| 1537 | |
| 1538 | static struct miscdevice vga_arb_device = { |
| 1539 | MISC_DYNAMIC_MINOR, "vga_arbiter", &vga_arb_device_fops |
| 1540 | }; |
| 1541 | |
Bjorn Helgaas | 505a1b5 | 2017-10-12 22:47:29 -0500 | [diff] [blame] | 1542 | static int __init vga_arb_device_init(void) |
| 1543 | { |
| 1544 | int rc; |
| 1545 | struct pci_dev *pdev; |
Bjorn Helgaas | 505a1b5 | 2017-10-12 22:47:29 -0500 | [diff] [blame] | 1546 | |
| 1547 | rc = misc_register(&vga_arb_device); |
| 1548 | if (rc < 0) |
| 1549 | pr_err("error %d registering device\n", rc); |
| 1550 | |
| 1551 | bus_register_notifier(&pci_bus_type, &pci_notifier); |
| 1552 | |
| 1553 | /* We add all PCI devices satisfying VGA class in the arbiter by |
| 1554 | * default */ |
| 1555 | pdev = NULL; |
| 1556 | while ((pdev = |
| 1557 | pci_get_subsys(PCI_ANY_ID, PCI_ANY_ID, PCI_ANY_ID, |
| 1558 | PCI_ANY_ID, pdev)) != NULL) |
| 1559 | vga_arbiter_add_pci_device(pdev); |
| 1560 | |
Bjorn Helgaas | a75d68f | 2016-11-17 11:47:58 -0600 | [diff] [blame] | 1561 | pr_info("loaded\n"); |
Benjamin Herrenschmidt | deb2d2e | 2009-08-11 15:52:06 +1000 | [diff] [blame] | 1562 | return rc; |
| 1563 | } |
Bjorn Helgaas | 1d38fe6 | 2022-02-24 16:47:43 -0600 | [diff] [blame] | 1564 | subsys_initcall_sync(vga_arb_device_init); |