Commit | Line | Data |
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deb2d2ec | 1 | /* |
c0db9cbc TV |
2 | * vgaarb.c: Implements the VGA arbitration. For details refer to |
3 | * Documentation/vgaarbiter.txt | |
4 | * | |
deb2d2ec BH |
5 | * |
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> | |
9 | * | |
c0db9cbc TV |
10 | * Permission is hereby granted, free of charge, to any person obtaining a |
11 | * copy of this software and associated documentation files (the "Software"), | |
12 | * to deal in the Software without restriction, including without limitation | |
13 | * the rights to use, copy, modify, merge, publish, distribute, sublicense, | |
14 | * and/or sell copies of the Software, and to permit persons to whom the | |
15 | * Software is furnished to do so, subject to the following conditions: | |
16 | * | |
17 | * The above copyright notice and this permission notice (including the next | |
18 | * paragraph) shall be included in all copies or substantial portions of the | |
19 | * Software. | |
20 | * | |
21 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
22 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
23 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL | |
24 | * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER | |
25 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING | |
26 | * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER | |
27 | * DEALINGS | |
28 | * IN THE SOFTWARE. | |
29 | * | |
deb2d2ec BH |
30 | */ |
31 | ||
32 | #include <linux/module.h> | |
33 | #include <linux/kernel.h> | |
34 | #include <linux/pci.h> | |
35 | #include <linux/errno.h> | |
36 | #include <linux/init.h> | |
37 | #include <linux/list.h> | |
38 | #include <linux/sched.h> | |
39 | #include <linux/wait.h> | |
40 | #include <linux/spinlock.h> | |
41 | #include <linux/poll.h> | |
42 | #include <linux/miscdevice.h> | |
5a0e3ad6 | 43 | #include <linux/slab.h> |
deb2d2ec BH |
44 | |
45 | #include <linux/uaccess.h> | |
46 | ||
47 | #include <linux/vgaarb.h> | |
48 | ||
49 | static void vga_arbiter_notify_clients(void); | |
50 | /* | |
51 | * We keep a list of all vga devices in the system to speed | |
52 | * up the various operations of the arbiter | |
53 | */ | |
54 | struct vga_device { | |
55 | struct list_head list; | |
56 | struct pci_dev *pdev; | |
57 | unsigned int decodes; /* what does it decodes */ | |
58 | unsigned int owns; /* what does it owns */ | |
59 | unsigned int locks; /* what does it locks */ | |
60 | unsigned int io_lock_cnt; /* legacy IO lock count */ | |
61 | unsigned int mem_lock_cnt; /* legacy MEM lock count */ | |
62 | unsigned int io_norm_cnt; /* normal IO count */ | |
63 | unsigned int mem_norm_cnt; /* normal MEM count */ | |
64 | ||
65 | /* allow IRQ enable/disable hook */ | |
66 | void *cookie; | |
67 | void (*irq_set_state)(void *cookie, bool enable); | |
68 | unsigned int (*set_vga_decode)(void *cookie, bool decode); | |
69 | }; | |
70 | ||
71 | static LIST_HEAD(vga_list); | |
72 | static int vga_count, vga_decode_count; | |
73 | static bool vga_arbiter_used; | |
74 | static DEFINE_SPINLOCK(vga_lock); | |
75 | static DECLARE_WAIT_QUEUE_HEAD(vga_wait_queue); | |
76 | ||
77 | ||
78 | static const char *vga_iostate_to_str(unsigned int iostate) | |
79 | { | |
80 | /* Ignore VGA_RSRC_IO and VGA_RSRC_MEM */ | |
81 | iostate &= VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM; | |
82 | switch (iostate) { | |
83 | case VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM: | |
84 | return "io+mem"; | |
85 | case VGA_RSRC_LEGACY_IO: | |
86 | return "io"; | |
87 | case VGA_RSRC_LEGACY_MEM: | |
88 | return "mem"; | |
89 | } | |
90 | return "none"; | |
91 | } | |
92 | ||
93 | static int vga_str_to_iostate(char *buf, int str_size, int *io_state) | |
94 | { | |
95 | /* we could in theory hand out locks on IO and mem | |
96 | * separately to userspace but it can cause deadlocks */ | |
97 | if (strncmp(buf, "none", 4) == 0) { | |
98 | *io_state = VGA_RSRC_NONE; | |
99 | return 1; | |
100 | } | |
101 | ||
102 | /* XXX We're not chekcing the str_size! */ | |
103 | if (strncmp(buf, "io+mem", 6) == 0) | |
104 | goto both; | |
105 | else if (strncmp(buf, "io", 2) == 0) | |
106 | goto both; | |
107 | else if (strncmp(buf, "mem", 3) == 0) | |
108 | goto both; | |
109 | return 0; | |
110 | both: | |
111 | *io_state = VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM; | |
112 | return 1; | |
113 | } | |
114 | ||
115 | #ifndef __ARCH_HAS_VGA_DEFAULT_DEVICE | |
116 | /* this is only used a cookie - it should not be dereferenced */ | |
117 | static struct pci_dev *vga_default; | |
118 | #endif | |
119 | ||
120 | static void vga_arb_device_card_gone(struct pci_dev *pdev); | |
121 | ||
122 | /* Find somebody in our list */ | |
123 | static struct vga_device *vgadev_find(struct pci_dev *pdev) | |
124 | { | |
125 | struct vga_device *vgadev; | |
126 | ||
127 | list_for_each_entry(vgadev, &vga_list, list) | |
128 | if (pdev == vgadev->pdev) | |
129 | return vgadev; | |
130 | return NULL; | |
131 | } | |
132 | ||
133 | /* Returns the default VGA device (vgacon's babe) */ | |
134 | #ifndef __ARCH_HAS_VGA_DEFAULT_DEVICE | |
135 | struct pci_dev *vga_default_device(void) | |
136 | { | |
137 | return vga_default; | |
138 | } | |
139 | #endif | |
140 | ||
141 | static inline void vga_irq_set_state(struct vga_device *vgadev, bool state) | |
142 | { | |
143 | if (vgadev->irq_set_state) | |
144 | vgadev->irq_set_state(vgadev->cookie, state); | |
145 | } | |
146 | ||
147 | ||
148 | /* If we don't ever use VGA arb we should avoid | |
149 | turning off anything anywhere due to old X servers getting | |
150 | confused about the boot device not being VGA */ | |
151 | static void vga_check_first_use(void) | |
152 | { | |
153 | /* we should inform all GPUs in the system that | |
154 | * VGA arb has occured and to try and disable resources | |
155 | * if they can */ | |
156 | if (!vga_arbiter_used) { | |
157 | vga_arbiter_used = true; | |
158 | vga_arbiter_notify_clients(); | |
159 | } | |
160 | } | |
161 | ||
162 | static struct vga_device *__vga_tryget(struct vga_device *vgadev, | |
163 | unsigned int rsrc) | |
164 | { | |
165 | unsigned int wants, legacy_wants, match; | |
166 | struct vga_device *conflict; | |
167 | unsigned int pci_bits; | |
168 | /* Account for "normal" resources to lock. If we decode the legacy, | |
169 | * counterpart, we need to request it as well | |
170 | */ | |
171 | if ((rsrc & VGA_RSRC_NORMAL_IO) && | |
172 | (vgadev->decodes & VGA_RSRC_LEGACY_IO)) | |
173 | rsrc |= VGA_RSRC_LEGACY_IO; | |
174 | if ((rsrc & VGA_RSRC_NORMAL_MEM) && | |
175 | (vgadev->decodes & VGA_RSRC_LEGACY_MEM)) | |
176 | rsrc |= VGA_RSRC_LEGACY_MEM; | |
177 | ||
2d6e9b91 TV |
178 | pr_debug("%s: %d\n", __func__, rsrc); |
179 | pr_debug("%s: owns: %d\n", __func__, vgadev->owns); | |
deb2d2ec BH |
180 | |
181 | /* Check what resources we need to acquire */ | |
182 | wants = rsrc & ~vgadev->owns; | |
183 | ||
184 | /* We already own everything, just mark locked & bye bye */ | |
185 | if (wants == 0) | |
186 | goto lock_them; | |
187 | ||
188 | /* We don't need to request a legacy resource, we just enable | |
189 | * appropriate decoding and go | |
190 | */ | |
191 | legacy_wants = wants & VGA_RSRC_LEGACY_MASK; | |
192 | if (legacy_wants == 0) | |
193 | goto enable_them; | |
194 | ||
195 | /* Ok, we don't, let's find out how we need to kick off */ | |
196 | list_for_each_entry(conflict, &vga_list, list) { | |
197 | unsigned int lwants = legacy_wants; | |
198 | unsigned int change_bridge = 0; | |
199 | ||
200 | /* Don't conflict with myself */ | |
201 | if (vgadev == conflict) | |
202 | continue; | |
203 | ||
204 | /* Check if the architecture allows a conflict between those | |
205 | * 2 devices or if they are on separate domains | |
206 | */ | |
207 | if (!vga_conflicts(vgadev->pdev, conflict->pdev)) | |
208 | continue; | |
209 | ||
210 | /* We have a possible conflict. before we go further, we must | |
211 | * check if we sit on the same bus as the conflicting device. | |
212 | * if we don't, then we must tie both IO and MEM resources | |
213 | * together since there is only a single bit controlling | |
214 | * VGA forwarding on P2P bridges | |
215 | */ | |
216 | if (vgadev->pdev->bus != conflict->pdev->bus) { | |
217 | change_bridge = 1; | |
218 | lwants = VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM; | |
219 | } | |
220 | ||
221 | /* Check if the guy has a lock on the resource. If he does, | |
222 | * return the conflicting entry | |
223 | */ | |
224 | if (conflict->locks & lwants) | |
225 | return conflict; | |
226 | ||
227 | /* Ok, now check if he owns the resource we want. We don't need | |
228 | * to check "decodes" since it should be impossible to own | |
229 | * own legacy resources you don't decode unless I have a bug | |
230 | * in this code... | |
231 | */ | |
232 | WARN_ON(conflict->owns & ~conflict->decodes); | |
233 | match = lwants & conflict->owns; | |
234 | if (!match) | |
235 | continue; | |
236 | ||
237 | /* looks like he doesn't have a lock, we can steal | |
238 | * them from him | |
239 | */ | |
240 | vga_irq_set_state(conflict, false); | |
241 | ||
242 | pci_bits = 0; | |
243 | if (lwants & (VGA_RSRC_LEGACY_MEM|VGA_RSRC_NORMAL_MEM)) | |
244 | pci_bits |= PCI_COMMAND_MEMORY; | |
245 | if (lwants & (VGA_RSRC_LEGACY_IO|VGA_RSRC_NORMAL_IO)) | |
246 | pci_bits |= PCI_COMMAND_IO; | |
247 | ||
248 | pci_set_vga_state(conflict->pdev, false, pci_bits, | |
249 | change_bridge); | |
250 | conflict->owns &= ~lwants; | |
251 | /* If he also owned non-legacy, that is no longer the case */ | |
252 | if (lwants & VGA_RSRC_LEGACY_MEM) | |
253 | conflict->owns &= ~VGA_RSRC_NORMAL_MEM; | |
254 | if (lwants & VGA_RSRC_LEGACY_IO) | |
255 | conflict->owns &= ~VGA_RSRC_NORMAL_IO; | |
256 | } | |
257 | ||
258 | enable_them: | |
259 | /* ok dude, we got it, everybody conflicting has been disabled, let's | |
260 | * enable us. Make sure we don't mark a bit in "owns" that we don't | |
261 | * also have in "decodes". We can lock resources we don't decode but | |
262 | * not own them. | |
263 | */ | |
264 | pci_bits = 0; | |
265 | if (wants & (VGA_RSRC_LEGACY_MEM|VGA_RSRC_NORMAL_MEM)) | |
266 | pci_bits |= PCI_COMMAND_MEMORY; | |
267 | if (wants & (VGA_RSRC_LEGACY_IO|VGA_RSRC_NORMAL_IO)) | |
268 | pci_bits |= PCI_COMMAND_IO; | |
269 | pci_set_vga_state(vgadev->pdev, true, pci_bits, !!(wants & VGA_RSRC_LEGACY_MASK)); | |
270 | ||
271 | vga_irq_set_state(vgadev, true); | |
272 | vgadev->owns |= (wants & vgadev->decodes); | |
273 | lock_them: | |
274 | vgadev->locks |= (rsrc & VGA_RSRC_LEGACY_MASK); | |
275 | if (rsrc & VGA_RSRC_LEGACY_IO) | |
276 | vgadev->io_lock_cnt++; | |
277 | if (rsrc & VGA_RSRC_LEGACY_MEM) | |
278 | vgadev->mem_lock_cnt++; | |
279 | if (rsrc & VGA_RSRC_NORMAL_IO) | |
280 | vgadev->io_norm_cnt++; | |
281 | if (rsrc & VGA_RSRC_NORMAL_MEM) | |
282 | vgadev->mem_norm_cnt++; | |
283 | ||
284 | return NULL; | |
285 | } | |
286 | ||
287 | static void __vga_put(struct vga_device *vgadev, unsigned int rsrc) | |
288 | { | |
289 | unsigned int old_locks = vgadev->locks; | |
290 | ||
2d6e9b91 | 291 | pr_debug("%s\n", __func__); |
deb2d2ec BH |
292 | |
293 | /* Update our counters, and account for equivalent legacy resources | |
294 | * if we decode them | |
295 | */ | |
296 | if ((rsrc & VGA_RSRC_NORMAL_IO) && vgadev->io_norm_cnt > 0) { | |
297 | vgadev->io_norm_cnt--; | |
298 | if (vgadev->decodes & VGA_RSRC_LEGACY_IO) | |
299 | rsrc |= VGA_RSRC_LEGACY_IO; | |
300 | } | |
301 | if ((rsrc & VGA_RSRC_NORMAL_MEM) && vgadev->mem_norm_cnt > 0) { | |
302 | vgadev->mem_norm_cnt--; | |
303 | if (vgadev->decodes & VGA_RSRC_LEGACY_MEM) | |
304 | rsrc |= VGA_RSRC_LEGACY_MEM; | |
305 | } | |
306 | if ((rsrc & VGA_RSRC_LEGACY_IO) && vgadev->io_lock_cnt > 0) | |
307 | vgadev->io_lock_cnt--; | |
308 | if ((rsrc & VGA_RSRC_LEGACY_MEM) && vgadev->mem_lock_cnt > 0) | |
309 | vgadev->mem_lock_cnt--; | |
310 | ||
311 | /* Just clear lock bits, we do lazy operations so we don't really | |
312 | * have to bother about anything else at this point | |
313 | */ | |
314 | if (vgadev->io_lock_cnt == 0) | |
315 | vgadev->locks &= ~VGA_RSRC_LEGACY_IO; | |
316 | if (vgadev->mem_lock_cnt == 0) | |
317 | vgadev->locks &= ~VGA_RSRC_LEGACY_MEM; | |
318 | ||
319 | /* Kick the wait queue in case somebody was waiting if we actually | |
320 | * released something | |
321 | */ | |
322 | if (old_locks != vgadev->locks) | |
323 | wake_up_all(&vga_wait_queue); | |
324 | } | |
325 | ||
326 | int vga_get(struct pci_dev *pdev, unsigned int rsrc, int interruptible) | |
327 | { | |
328 | struct vga_device *vgadev, *conflict; | |
329 | unsigned long flags; | |
330 | wait_queue_t wait; | |
331 | int rc = 0; | |
332 | ||
333 | vga_check_first_use(); | |
334 | /* The one who calls us should check for this, but lets be sure... */ | |
335 | if (pdev == NULL) | |
336 | pdev = vga_default_device(); | |
337 | if (pdev == NULL) | |
338 | return 0; | |
339 | ||
340 | for (;;) { | |
341 | spin_lock_irqsave(&vga_lock, flags); | |
342 | vgadev = vgadev_find(pdev); | |
343 | if (vgadev == NULL) { | |
344 | spin_unlock_irqrestore(&vga_lock, flags); | |
345 | rc = -ENODEV; | |
346 | break; | |
347 | } | |
348 | conflict = __vga_tryget(vgadev, rsrc); | |
349 | spin_unlock_irqrestore(&vga_lock, flags); | |
350 | if (conflict == NULL) | |
351 | break; | |
352 | ||
353 | ||
354 | /* We have a conflict, we wait until somebody kicks the | |
355 | * work queue. Currently we have one work queue that we | |
356 | * kick each time some resources are released, but it would | |
357 | * be fairly easy to have a per device one so that we only | |
358 | * need to attach to the conflicting device | |
359 | */ | |
360 | init_waitqueue_entry(&wait, current); | |
361 | add_wait_queue(&vga_wait_queue, &wait); | |
362 | set_current_state(interruptible ? | |
363 | TASK_INTERRUPTIBLE : | |
364 | TASK_UNINTERRUPTIBLE); | |
365 | if (signal_pending(current)) { | |
366 | rc = -EINTR; | |
367 | break; | |
368 | } | |
369 | schedule(); | |
370 | remove_wait_queue(&vga_wait_queue, &wait); | |
371 | set_current_state(TASK_RUNNING); | |
372 | } | |
373 | return rc; | |
374 | } | |
375 | EXPORT_SYMBOL(vga_get); | |
376 | ||
377 | int vga_tryget(struct pci_dev *pdev, unsigned int rsrc) | |
378 | { | |
379 | struct vga_device *vgadev; | |
380 | unsigned long flags; | |
381 | int rc = 0; | |
382 | ||
383 | vga_check_first_use(); | |
384 | ||
385 | /* The one who calls us should check for this, but lets be sure... */ | |
386 | if (pdev == NULL) | |
387 | pdev = vga_default_device(); | |
388 | if (pdev == NULL) | |
389 | return 0; | |
390 | spin_lock_irqsave(&vga_lock, flags); | |
391 | vgadev = vgadev_find(pdev); | |
392 | if (vgadev == NULL) { | |
393 | rc = -ENODEV; | |
394 | goto bail; | |
395 | } | |
396 | if (__vga_tryget(vgadev, rsrc)) | |
397 | rc = -EBUSY; | |
398 | bail: | |
399 | spin_unlock_irqrestore(&vga_lock, flags); | |
400 | return rc; | |
401 | } | |
402 | EXPORT_SYMBOL(vga_tryget); | |
403 | ||
404 | void vga_put(struct pci_dev *pdev, unsigned int rsrc) | |
405 | { | |
406 | struct vga_device *vgadev; | |
407 | unsigned long flags; | |
408 | ||
409 | /* The one who calls us should check for this, but lets be sure... */ | |
410 | if (pdev == NULL) | |
411 | pdev = vga_default_device(); | |
412 | if (pdev == NULL) | |
413 | return; | |
414 | spin_lock_irqsave(&vga_lock, flags); | |
415 | vgadev = vgadev_find(pdev); | |
416 | if (vgadev == NULL) | |
417 | goto bail; | |
418 | __vga_put(vgadev, rsrc); | |
419 | bail: | |
420 | spin_unlock_irqrestore(&vga_lock, flags); | |
421 | } | |
422 | EXPORT_SYMBOL(vga_put); | |
423 | ||
424 | /* | |
425 | * Currently, we assume that the "initial" setup of the system is | |
426 | * not sane, that is we come up with conflicting devices and let | |
427 | * the arbiter's client decides if devices decodes or not legacy | |
428 | * things. | |
429 | */ | |
430 | static bool vga_arbiter_add_pci_device(struct pci_dev *pdev) | |
431 | { | |
432 | struct vga_device *vgadev; | |
433 | unsigned long flags; | |
434 | struct pci_bus *bus; | |
435 | struct pci_dev *bridge; | |
436 | u16 cmd; | |
437 | ||
438 | /* Only deal with VGA class devices */ | |
439 | if ((pdev->class >> 8) != PCI_CLASS_DISPLAY_VGA) | |
440 | return false; | |
441 | ||
442 | /* Allocate structure */ | |
443 | vgadev = kmalloc(sizeof(struct vga_device), GFP_KERNEL); | |
444 | if (vgadev == NULL) { | |
445 | pr_err("vgaarb: failed to allocate pci device\n"); | |
446 | /* What to do on allocation failure ? For now, let's | |
447 | * just do nothing, I'm not sure there is anything saner | |
448 | * to be done | |
449 | */ | |
450 | return false; | |
451 | } | |
452 | ||
453 | memset(vgadev, 0, sizeof(*vgadev)); | |
454 | ||
455 | /* Take lock & check for duplicates */ | |
456 | spin_lock_irqsave(&vga_lock, flags); | |
457 | if (vgadev_find(pdev) != NULL) { | |
458 | BUG_ON(1); | |
459 | goto fail; | |
460 | } | |
461 | vgadev->pdev = pdev; | |
462 | ||
463 | /* By default, assume we decode everything */ | |
464 | vgadev->decodes = VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM | | |
465 | VGA_RSRC_NORMAL_IO | VGA_RSRC_NORMAL_MEM; | |
466 | ||
467 | /* by default mark it as decoding */ | |
468 | vga_decode_count++; | |
469 | /* Mark that we "own" resources based on our enables, we will | |
470 | * clear that below if the bridge isn't forwarding | |
471 | */ | |
472 | pci_read_config_word(pdev, PCI_COMMAND, &cmd); | |
473 | if (cmd & PCI_COMMAND_IO) | |
474 | vgadev->owns |= VGA_RSRC_LEGACY_IO; | |
475 | if (cmd & PCI_COMMAND_MEMORY) | |
476 | vgadev->owns |= VGA_RSRC_LEGACY_MEM; | |
477 | ||
478 | /* Check if VGA cycles can get down to us */ | |
479 | bus = pdev->bus; | |
480 | while (bus) { | |
481 | bridge = bus->self; | |
482 | if (bridge) { | |
483 | u16 l; | |
484 | pci_read_config_word(bridge, PCI_BRIDGE_CONTROL, | |
485 | &l); | |
486 | if (!(l & PCI_BRIDGE_CTL_VGA)) { | |
487 | vgadev->owns = 0; | |
488 | break; | |
489 | } | |
490 | } | |
491 | bus = bus->parent; | |
492 | } | |
493 | ||
494 | /* Deal with VGA default device. Use first enabled one | |
495 | * by default if arch doesn't have it's own hook | |
496 | */ | |
497 | #ifndef __ARCH_HAS_VGA_DEFAULT_DEVICE | |
498 | if (vga_default == NULL && | |
499 | ((vgadev->owns & VGA_RSRC_LEGACY_MASK) == VGA_RSRC_LEGACY_MASK)) | |
500 | vga_default = pci_dev_get(pdev); | |
501 | #endif | |
502 | ||
503 | /* Add to the list */ | |
504 | list_add(&vgadev->list, &vga_list); | |
505 | vga_count++; | |
506 | pr_info("vgaarb: device added: PCI:%s,decodes=%s,owns=%s,locks=%s\n", | |
507 | pci_name(pdev), | |
508 | vga_iostate_to_str(vgadev->decodes), | |
509 | vga_iostate_to_str(vgadev->owns), | |
510 | vga_iostate_to_str(vgadev->locks)); | |
511 | ||
512 | spin_unlock_irqrestore(&vga_lock, flags); | |
513 | return true; | |
514 | fail: | |
515 | spin_unlock_irqrestore(&vga_lock, flags); | |
516 | kfree(vgadev); | |
517 | return false; | |
518 | } | |
519 | ||
520 | static bool vga_arbiter_del_pci_device(struct pci_dev *pdev) | |
521 | { | |
522 | struct vga_device *vgadev; | |
523 | unsigned long flags; | |
524 | bool ret = true; | |
525 | ||
526 | spin_lock_irqsave(&vga_lock, flags); | |
527 | vgadev = vgadev_find(pdev); | |
528 | if (vgadev == NULL) { | |
529 | ret = false; | |
530 | goto bail; | |
531 | } | |
532 | ||
533 | if (vga_default == pdev) { | |
534 | pci_dev_put(vga_default); | |
535 | vga_default = NULL; | |
536 | } | |
537 | ||
538 | if (vgadev->decodes & (VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM)) | |
539 | vga_decode_count--; | |
540 | ||
541 | /* Remove entry from list */ | |
542 | list_del(&vgadev->list); | |
543 | vga_count--; | |
544 | /* Notify userland driver that the device is gone so it discards | |
545 | * it's copies of the pci_dev pointer | |
546 | */ | |
547 | vga_arb_device_card_gone(pdev); | |
548 | ||
549 | /* Wake up all possible waiters */ | |
550 | wake_up_all(&vga_wait_queue); | |
551 | bail: | |
552 | spin_unlock_irqrestore(&vga_lock, flags); | |
553 | kfree(vgadev); | |
554 | return ret; | |
555 | } | |
556 | ||
557 | /* this is called with the lock */ | |
558 | static inline void vga_update_device_decodes(struct vga_device *vgadev, | |
559 | int new_decodes) | |
560 | { | |
561 | int old_decodes; | |
562 | struct vga_device *new_vgadev, *conflict; | |
563 | ||
564 | old_decodes = vgadev->decodes; | |
565 | vgadev->decodes = new_decodes; | |
566 | ||
567 | pr_info("vgaarb: device changed decodes: PCI:%s,olddecodes=%s,decodes=%s:owns=%s\n", | |
568 | pci_name(vgadev->pdev), | |
569 | vga_iostate_to_str(old_decodes), | |
570 | vga_iostate_to_str(vgadev->decodes), | |
571 | vga_iostate_to_str(vgadev->owns)); | |
572 | ||
573 | ||
574 | /* if we own the decodes we should move them along to | |
575 | another card */ | |
576 | if ((vgadev->owns & old_decodes) && (vga_count > 1)) { | |
577 | /* set us to own nothing */ | |
578 | vgadev->owns &= ~old_decodes; | |
579 | list_for_each_entry(new_vgadev, &vga_list, list) { | |
580 | if ((new_vgadev != vgadev) && | |
581 | (new_vgadev->decodes & VGA_RSRC_LEGACY_MASK)) { | |
582 | pr_info("vgaarb: transferring owner from PCI:%s to PCI:%s\n", pci_name(vgadev->pdev), pci_name(new_vgadev->pdev)); | |
583 | conflict = __vga_tryget(new_vgadev, VGA_RSRC_LEGACY_MASK); | |
584 | if (!conflict) | |
585 | __vga_put(new_vgadev, VGA_RSRC_LEGACY_MASK); | |
586 | break; | |
587 | } | |
588 | } | |
589 | } | |
590 | ||
591 | /* change decodes counter */ | |
592 | if (old_decodes != new_decodes) { | |
593 | if (new_decodes & (VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM)) | |
594 | vga_decode_count++; | |
595 | else | |
596 | vga_decode_count--; | |
597 | } | |
2d6e9b91 | 598 | pr_debug("vgaarb: decoding count now is: %d\n", vga_decode_count); |
deb2d2ec BH |
599 | } |
600 | ||
201ba4c4 | 601 | static void __vga_set_legacy_decoding(struct pci_dev *pdev, unsigned int decodes, bool userspace) |
deb2d2ec BH |
602 | { |
603 | struct vga_device *vgadev; | |
604 | unsigned long flags; | |
605 | ||
606 | decodes &= VGA_RSRC_LEGACY_MASK; | |
607 | ||
608 | spin_lock_irqsave(&vga_lock, flags); | |
609 | vgadev = vgadev_find(pdev); | |
610 | if (vgadev == NULL) | |
611 | goto bail; | |
612 | ||
613 | /* don't let userspace futz with kernel driver decodes */ | |
614 | if (userspace && vgadev->set_vga_decode) | |
615 | goto bail; | |
616 | ||
617 | /* update the device decodes + counter */ | |
618 | vga_update_device_decodes(vgadev, decodes); | |
619 | ||
620 | /* XXX if somebody is going from "doesn't decode" to "decodes" state | |
621 | * here, additional care must be taken as we may have pending owner | |
622 | * ship of non-legacy region ... | |
623 | */ | |
624 | bail: | |
625 | spin_unlock_irqrestore(&vga_lock, flags); | |
626 | } | |
627 | ||
628 | void vga_set_legacy_decoding(struct pci_dev *pdev, unsigned int decodes) | |
629 | { | |
630 | __vga_set_legacy_decoding(pdev, decodes, false); | |
631 | } | |
632 | EXPORT_SYMBOL(vga_set_legacy_decoding); | |
633 | ||
deb2d2ec BH |
634 | /* call with NULL to unregister */ |
635 | int vga_client_register(struct pci_dev *pdev, void *cookie, | |
636 | void (*irq_set_state)(void *cookie, bool state), | |
637 | unsigned int (*set_vga_decode)(void *cookie, bool decode)) | |
638 | { | |
639 | int ret = -1; | |
640 | struct vga_device *vgadev; | |
641 | unsigned long flags; | |
642 | ||
643 | spin_lock_irqsave(&vga_lock, flags); | |
644 | vgadev = vgadev_find(pdev); | |
645 | if (!vgadev) | |
646 | goto bail; | |
647 | ||
648 | vgadev->irq_set_state = irq_set_state; | |
649 | vgadev->set_vga_decode = set_vga_decode; | |
650 | vgadev->cookie = cookie; | |
651 | ret = 0; | |
652 | ||
653 | bail: | |
654 | spin_unlock_irqrestore(&vga_lock, flags); | |
655 | return ret; | |
656 | ||
657 | } | |
658 | EXPORT_SYMBOL(vga_client_register); | |
659 | ||
660 | /* | |
661 | * Char driver implementation | |
662 | * | |
663 | * Semantics is: | |
664 | * | |
665 | * open : open user instance of the arbitrer. by default, it's | |
666 | * attached to the default VGA device of the system. | |
667 | * | |
668 | * close : close user instance, release locks | |
669 | * | |
670 | * read : return a string indicating the status of the target. | |
671 | * an IO state string is of the form {io,mem,io+mem,none}, | |
672 | * mc and ic are respectively mem and io lock counts (for | |
673 | * debugging/diagnostic only). "decodes" indicate what the | |
674 | * card currently decodes, "owns" indicates what is currently | |
675 | * enabled on it, and "locks" indicates what is locked by this | |
676 | * card. If the card is unplugged, we get "invalid" then for | |
677 | * card_ID and an -ENODEV error is returned for any command | |
678 | * until a new card is targeted | |
679 | * | |
680 | * "<card_ID>,decodes=<io_state>,owns=<io_state>,locks=<io_state> (ic,mc)" | |
681 | * | |
682 | * write : write a command to the arbiter. List of commands is: | |
683 | * | |
684 | * target <card_ID> : switch target to card <card_ID> (see below) | |
685 | * lock <io_state> : acquires locks on target ("none" is invalid io_state) | |
686 | * trylock <io_state> : non-blocking acquire locks on target | |
687 | * unlock <io_state> : release locks on target | |
688 | * unlock all : release all locks on target held by this user | |
689 | * decodes <io_state> : set the legacy decoding attributes for the card | |
690 | * | |
691 | * poll : event if something change on any card (not just the target) | |
692 | * | |
693 | * card_ID is of the form "PCI:domain:bus:dev.fn". It can be set to "default" | |
694 | * to go back to the system default card (TODO: not implemented yet). | |
695 | * Currently, only PCI is supported as a prefix, but the userland API may | |
696 | * support other bus types in the future, even if the current kernel | |
697 | * implementation doesn't. | |
698 | * | |
699 | * Note about locks: | |
700 | * | |
701 | * The driver keeps track of which user has what locks on which card. It | |
702 | * supports stacking, like the kernel one. This complexifies the implementation | |
703 | * a bit, but makes the arbiter more tolerant to userspace problems and able | |
704 | * to properly cleanup in all cases when a process dies. | |
705 | * Currently, a max of 16 cards simultaneously can have locks issued from | |
706 | * userspace for a given user (file descriptor instance) of the arbiter. | |
707 | * | |
708 | * If the device is hot-unplugged, there is a hook inside the module to notify | |
709 | * they being added/removed in the system and automatically added/removed in | |
710 | * the arbiter. | |
711 | */ | |
712 | ||
36028f33 | 713 | #define MAX_USER_CARDS CONFIG_VGA_ARB_MAX_GPUS |
deb2d2ec BH |
714 | #define PCI_INVALID_CARD ((struct pci_dev *)-1UL) |
715 | ||
716 | /* | |
717 | * Each user has an array of these, tracking which cards have locks | |
718 | */ | |
719 | struct vga_arb_user_card { | |
720 | struct pci_dev *pdev; | |
721 | unsigned int mem_cnt; | |
722 | unsigned int io_cnt; | |
723 | }; | |
724 | ||
725 | struct vga_arb_private { | |
726 | struct list_head list; | |
727 | struct pci_dev *target; | |
728 | struct vga_arb_user_card cards[MAX_USER_CARDS]; | |
729 | spinlock_t lock; | |
730 | }; | |
731 | ||
732 | static LIST_HEAD(vga_user_list); | |
733 | static DEFINE_SPINLOCK(vga_user_lock); | |
734 | ||
735 | ||
736 | /* | |
737 | * This function gets a string in the format: "PCI:domain:bus:dev.fn" and | |
738 | * returns the respective values. If the string is not in this format, | |
739 | * it returns 0. | |
740 | */ | |
741 | static int vga_pci_str_to_vars(char *buf, int count, unsigned int *domain, | |
742 | unsigned int *bus, unsigned int *devfn) | |
743 | { | |
744 | int n; | |
745 | unsigned int slot, func; | |
746 | ||
747 | ||
748 | n = sscanf(buf, "PCI:%x:%x:%x.%x", domain, bus, &slot, &func); | |
749 | if (n != 4) | |
750 | return 0; | |
751 | ||
752 | *devfn = PCI_DEVFN(slot, func); | |
753 | ||
754 | return 1; | |
755 | } | |
756 | ||
757 | static ssize_t vga_arb_read(struct file *file, char __user * buf, | |
758 | size_t count, loff_t *ppos) | |
759 | { | |
760 | struct vga_arb_private *priv = file->private_data; | |
761 | struct vga_device *vgadev; | |
762 | struct pci_dev *pdev; | |
763 | unsigned long flags; | |
764 | size_t len; | |
765 | int rc; | |
766 | char *lbuf; | |
767 | ||
768 | lbuf = kmalloc(1024, GFP_KERNEL); | |
769 | if (lbuf == NULL) | |
770 | return -ENOMEM; | |
771 | ||
772 | /* Shields against vga_arb_device_card_gone (pci_dev going | |
773 | * away), and allows access to vga list | |
774 | */ | |
775 | spin_lock_irqsave(&vga_lock, flags); | |
776 | ||
777 | /* If we are targetting the default, use it */ | |
778 | pdev = priv->target; | |
779 | if (pdev == NULL || pdev == PCI_INVALID_CARD) { | |
780 | spin_unlock_irqrestore(&vga_lock, flags); | |
781 | len = sprintf(lbuf, "invalid"); | |
782 | goto done; | |
783 | } | |
784 | ||
785 | /* Find card vgadev structure */ | |
786 | vgadev = vgadev_find(pdev); | |
787 | if (vgadev == NULL) { | |
788 | /* Wow, it's not in the list, that shouldn't happen, | |
789 | * let's fix us up and return invalid card | |
790 | */ | |
791 | if (pdev == priv->target) | |
792 | vga_arb_device_card_gone(pdev); | |
793 | spin_unlock_irqrestore(&vga_lock, flags); | |
794 | len = sprintf(lbuf, "invalid"); | |
795 | goto done; | |
796 | } | |
797 | ||
798 | /* Fill the buffer with infos */ | |
799 | len = snprintf(lbuf, 1024, | |
800 | "count:%d,PCI:%s,decodes=%s,owns=%s,locks=%s(%d:%d)\n", | |
801 | vga_decode_count, pci_name(pdev), | |
802 | vga_iostate_to_str(vgadev->decodes), | |
803 | vga_iostate_to_str(vgadev->owns), | |
804 | vga_iostate_to_str(vgadev->locks), | |
805 | vgadev->io_lock_cnt, vgadev->mem_lock_cnt); | |
806 | ||
807 | spin_unlock_irqrestore(&vga_lock, flags); | |
808 | done: | |
809 | ||
810 | /* Copy that to user */ | |
811 | if (len > count) | |
812 | len = count; | |
813 | rc = copy_to_user(buf, lbuf, len); | |
814 | kfree(lbuf); | |
815 | if (rc) | |
816 | return -EFAULT; | |
817 | return len; | |
818 | } | |
819 | ||
820 | /* | |
821 | * TODO: To avoid parsing inside kernel and to improve the speed we may | |
822 | * consider use ioctl here | |
823 | */ | |
824 | static ssize_t vga_arb_write(struct file *file, const char __user * buf, | |
825 | size_t count, loff_t *ppos) | |
826 | { | |
827 | struct vga_arb_private *priv = file->private_data; | |
828 | struct vga_arb_user_card *uc = NULL; | |
829 | struct pci_dev *pdev; | |
830 | ||
831 | unsigned int io_state; | |
832 | ||
833 | char *kbuf, *curr_pos; | |
834 | size_t remaining = count; | |
835 | ||
836 | int ret_val; | |
837 | int i; | |
838 | ||
839 | ||
840 | kbuf = kmalloc(count + 1, GFP_KERNEL); | |
841 | if (!kbuf) | |
842 | return -ENOMEM; | |
843 | ||
844 | if (copy_from_user(kbuf, buf, count)) { | |
845 | kfree(kbuf); | |
846 | return -EFAULT; | |
847 | } | |
848 | curr_pos = kbuf; | |
849 | kbuf[count] = '\0'; /* Just to make sure... */ | |
850 | ||
851 | if (strncmp(curr_pos, "lock ", 5) == 0) { | |
852 | curr_pos += 5; | |
853 | remaining -= 5; | |
854 | ||
2d6e9b91 | 855 | pr_debug("client 0x%p called 'lock'\n", priv); |
deb2d2ec BH |
856 | |
857 | if (!vga_str_to_iostate(curr_pos, remaining, &io_state)) { | |
858 | ret_val = -EPROTO; | |
859 | goto done; | |
860 | } | |
861 | if (io_state == VGA_RSRC_NONE) { | |
862 | ret_val = -EPROTO; | |
863 | goto done; | |
864 | } | |
865 | ||
866 | pdev = priv->target; | |
867 | if (priv->target == NULL) { | |
868 | ret_val = -ENODEV; | |
869 | goto done; | |
870 | } | |
871 | ||
872 | vga_get_uninterruptible(pdev, io_state); | |
873 | ||
874 | /* Update the client's locks lists... */ | |
875 | for (i = 0; i < MAX_USER_CARDS; i++) { | |
876 | if (priv->cards[i].pdev == pdev) { | |
877 | if (io_state & VGA_RSRC_LEGACY_IO) | |
878 | priv->cards[i].io_cnt++; | |
879 | if (io_state & VGA_RSRC_LEGACY_MEM) | |
880 | priv->cards[i].mem_cnt++; | |
881 | break; | |
882 | } | |
883 | } | |
884 | ||
885 | ret_val = count; | |
886 | goto done; | |
887 | } else if (strncmp(curr_pos, "unlock ", 7) == 0) { | |
888 | curr_pos += 7; | |
889 | remaining -= 7; | |
890 | ||
2d6e9b91 | 891 | pr_debug("client 0x%p called 'unlock'\n", priv); |
deb2d2ec BH |
892 | |
893 | if (strncmp(curr_pos, "all", 3) == 0) | |
894 | io_state = VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM; | |
895 | else { | |
896 | if (!vga_str_to_iostate | |
897 | (curr_pos, remaining, &io_state)) { | |
898 | ret_val = -EPROTO; | |
899 | goto done; | |
900 | } | |
901 | /* TODO: Add this? | |
902 | if (io_state == VGA_RSRC_NONE) { | |
903 | ret_val = -EPROTO; | |
904 | goto done; | |
905 | } | |
906 | */ | |
907 | } | |
908 | ||
909 | pdev = priv->target; | |
910 | if (priv->target == NULL) { | |
911 | ret_val = -ENODEV; | |
912 | goto done; | |
913 | } | |
914 | for (i = 0; i < MAX_USER_CARDS; i++) { | |
915 | if (priv->cards[i].pdev == pdev) | |
916 | uc = &priv->cards[i]; | |
917 | } | |
918 | ||
919 | if (!uc) | |
920 | return -EINVAL; | |
921 | ||
922 | if (io_state & VGA_RSRC_LEGACY_IO && uc->io_cnt == 0) | |
923 | return -EINVAL; | |
924 | ||
925 | if (io_state & VGA_RSRC_LEGACY_MEM && uc->mem_cnt == 0) | |
926 | return -EINVAL; | |
927 | ||
928 | vga_put(pdev, io_state); | |
929 | ||
930 | if (io_state & VGA_RSRC_LEGACY_IO) | |
931 | uc->io_cnt--; | |
932 | if (io_state & VGA_RSRC_LEGACY_MEM) | |
933 | uc->mem_cnt--; | |
934 | ||
935 | ret_val = count; | |
936 | goto done; | |
937 | } else if (strncmp(curr_pos, "trylock ", 8) == 0) { | |
938 | curr_pos += 8; | |
939 | remaining -= 8; | |
940 | ||
2d6e9b91 | 941 | pr_debug("client 0x%p called 'trylock'\n", priv); |
deb2d2ec BH |
942 | |
943 | if (!vga_str_to_iostate(curr_pos, remaining, &io_state)) { | |
944 | ret_val = -EPROTO; | |
945 | goto done; | |
946 | } | |
947 | /* TODO: Add this? | |
948 | if (io_state == VGA_RSRC_NONE) { | |
949 | ret_val = -EPROTO; | |
950 | goto done; | |
951 | } | |
952 | */ | |
953 | ||
954 | pdev = priv->target; | |
955 | if (priv->target == NULL) { | |
956 | ret_val = -ENODEV; | |
957 | goto done; | |
958 | } | |
959 | ||
960 | if (vga_tryget(pdev, io_state)) { | |
961 | /* Update the client's locks lists... */ | |
962 | for (i = 0; i < MAX_USER_CARDS; i++) { | |
963 | if (priv->cards[i].pdev == pdev) { | |
964 | if (io_state & VGA_RSRC_LEGACY_IO) | |
965 | priv->cards[i].io_cnt++; | |
966 | if (io_state & VGA_RSRC_LEGACY_MEM) | |
967 | priv->cards[i].mem_cnt++; | |
968 | break; | |
969 | } | |
970 | } | |
971 | ret_val = count; | |
972 | goto done; | |
973 | } else { | |
974 | ret_val = -EBUSY; | |
975 | goto done; | |
976 | } | |
977 | ||
978 | } else if (strncmp(curr_pos, "target ", 7) == 0) { | |
773a38db | 979 | struct pci_bus *pbus; |
deb2d2ec BH |
980 | unsigned int domain, bus, devfn; |
981 | struct vga_device *vgadev; | |
982 | ||
983 | curr_pos += 7; | |
984 | remaining -= 7; | |
2d6e9b91 | 985 | pr_debug("client 0x%p called 'target'\n", priv); |
deb2d2ec | 986 | /* if target is default */ |
2cc9116c | 987 | if (!strncmp(curr_pos, "default", 7)) |
deb2d2ec BH |
988 | pdev = pci_dev_get(vga_default_device()); |
989 | else { | |
990 | if (!vga_pci_str_to_vars(curr_pos, remaining, | |
991 | &domain, &bus, &devfn)) { | |
992 | ret_val = -EPROTO; | |
993 | goto done; | |
994 | } | |
2d6e9b91 | 995 | pr_debug("vgaarb: %s ==> %x:%x:%x.%x\n", curr_pos, |
773a38db MT |
996 | domain, bus, PCI_SLOT(devfn), PCI_FUNC(devfn)); |
997 | ||
998 | pbus = pci_find_bus(domain, bus); | |
2d6e9b91 | 999 | pr_debug("vgaarb: pbus %p\n", pbus); |
773a38db MT |
1000 | if (pbus == NULL) { |
1001 | pr_err("vgaarb: invalid PCI domain and/or bus address %x:%x\n", | |
1002 | domain, bus); | |
1003 | ret_val = -ENODEV; | |
1004 | goto done; | |
1005 | } | |
1006 | pdev = pci_get_slot(pbus, devfn); | |
2d6e9b91 | 1007 | pr_debug("vgaarb: pdev %p\n", pdev); |
deb2d2ec | 1008 | if (!pdev) { |
773a38db MT |
1009 | pr_err("vgaarb: invalid PCI address %x:%x\n", |
1010 | bus, devfn); | |
deb2d2ec BH |
1011 | ret_val = -ENODEV; |
1012 | goto done; | |
1013 | } | |
1014 | } | |
1015 | ||
1016 | vgadev = vgadev_find(pdev); | |
2d6e9b91 | 1017 | pr_debug("vgaarb: vgadev %p\n", vgadev); |
deb2d2ec | 1018 | if (vgadev == NULL) { |
773a38db | 1019 | pr_err("vgaarb: this pci device is not a vga device\n"); |
deb2d2ec BH |
1020 | pci_dev_put(pdev); |
1021 | ret_val = -ENODEV; | |
1022 | goto done; | |
1023 | } | |
1024 | ||
1025 | priv->target = pdev; | |
1026 | for (i = 0; i < MAX_USER_CARDS; i++) { | |
1027 | if (priv->cards[i].pdev == pdev) | |
1028 | break; | |
1029 | if (priv->cards[i].pdev == NULL) { | |
1030 | priv->cards[i].pdev = pdev; | |
1031 | priv->cards[i].io_cnt = 0; | |
1032 | priv->cards[i].mem_cnt = 0; | |
1033 | break; | |
1034 | } | |
1035 | } | |
1036 | if (i == MAX_USER_CARDS) { | |
773a38db MT |
1037 | pr_err("vgaarb: maximum user cards (%d) number reached!\n", |
1038 | MAX_USER_CARDS); | |
deb2d2ec BH |
1039 | pci_dev_put(pdev); |
1040 | /* XXX: which value to return? */ | |
1041 | ret_val = -ENOMEM; | |
1042 | goto done; | |
1043 | } | |
1044 | ||
1045 | ret_val = count; | |
1046 | pci_dev_put(pdev); | |
1047 | goto done; | |
1048 | ||
1049 | ||
1050 | } else if (strncmp(curr_pos, "decodes ", 8) == 0) { | |
1051 | curr_pos += 8; | |
1052 | remaining -= 8; | |
2d6e9b91 | 1053 | pr_debug("vgaarb: client 0x%p called 'decodes'\n", priv); |
deb2d2ec BH |
1054 | |
1055 | if (!vga_str_to_iostate(curr_pos, remaining, &io_state)) { | |
1056 | ret_val = -EPROTO; | |
1057 | goto done; | |
1058 | } | |
1059 | pdev = priv->target; | |
1060 | if (priv->target == NULL) { | |
1061 | ret_val = -ENODEV; | |
1062 | goto done; | |
1063 | } | |
1064 | ||
1065 | __vga_set_legacy_decoding(pdev, io_state, true); | |
1066 | ret_val = count; | |
1067 | goto done; | |
1068 | } | |
1069 | /* If we got here, the message written is not part of the protocol! */ | |
1070 | kfree(kbuf); | |
1071 | return -EPROTO; | |
1072 | ||
1073 | done: | |
1074 | kfree(kbuf); | |
1075 | return ret_val; | |
1076 | } | |
1077 | ||
1078 | static unsigned int vga_arb_fpoll(struct file *file, poll_table * wait) | |
1079 | { | |
1080 | struct vga_arb_private *priv = file->private_data; | |
1081 | ||
2d6e9b91 | 1082 | pr_debug("%s\n", __func__); |
deb2d2ec BH |
1083 | |
1084 | if (priv == NULL) | |
1085 | return -ENODEV; | |
1086 | poll_wait(file, &vga_wait_queue, wait); | |
1087 | return POLLIN; | |
1088 | } | |
1089 | ||
1090 | static int vga_arb_open(struct inode *inode, struct file *file) | |
1091 | { | |
1092 | struct vga_arb_private *priv; | |
1093 | unsigned long flags; | |
1094 | ||
2d6e9b91 | 1095 | pr_debug("%s\n", __func__); |
deb2d2ec BH |
1096 | |
1097 | priv = kmalloc(sizeof(struct vga_arb_private), GFP_KERNEL); | |
1098 | if (priv == NULL) | |
1099 | return -ENOMEM; | |
1100 | memset(priv, 0, sizeof(*priv)); | |
1101 | spin_lock_init(&priv->lock); | |
1102 | file->private_data = priv; | |
1103 | ||
1104 | spin_lock_irqsave(&vga_user_lock, flags); | |
1105 | list_add(&priv->list, &vga_user_list); | |
1106 | spin_unlock_irqrestore(&vga_user_lock, flags); | |
1107 | ||
1108 | /* Set the client' lists of locks */ | |
1109 | priv->target = vga_default_device(); /* Maybe this is still null! */ | |
1110 | priv->cards[0].pdev = priv->target; | |
1111 | priv->cards[0].io_cnt = 0; | |
1112 | priv->cards[0].mem_cnt = 0; | |
1113 | ||
1114 | ||
1115 | return 0; | |
1116 | } | |
1117 | ||
1118 | static int vga_arb_release(struct inode *inode, struct file *file) | |
1119 | { | |
1120 | struct vga_arb_private *priv = file->private_data; | |
1121 | struct vga_arb_user_card *uc; | |
1122 | unsigned long flags; | |
1123 | int i; | |
1124 | ||
2d6e9b91 | 1125 | pr_debug("%s\n", __func__); |
deb2d2ec BH |
1126 | |
1127 | if (priv == NULL) | |
1128 | return -ENODEV; | |
1129 | ||
1130 | spin_lock_irqsave(&vga_user_lock, flags); | |
1131 | list_del(&priv->list); | |
1132 | for (i = 0; i < MAX_USER_CARDS; i++) { | |
1133 | uc = &priv->cards[i]; | |
1134 | if (uc->pdev == NULL) | |
1135 | continue; | |
2d6e9b91 | 1136 | pr_debug("uc->io_cnt == %d, uc->mem_cnt == %d\n", |
deb2d2ec BH |
1137 | uc->io_cnt, uc->mem_cnt); |
1138 | while (uc->io_cnt--) | |
1139 | vga_put(uc->pdev, VGA_RSRC_LEGACY_IO); | |
1140 | while (uc->mem_cnt--) | |
1141 | vga_put(uc->pdev, VGA_RSRC_LEGACY_MEM); | |
1142 | } | |
1143 | spin_unlock_irqrestore(&vga_user_lock, flags); | |
1144 | ||
1145 | kfree(priv); | |
1146 | ||
1147 | return 0; | |
1148 | } | |
1149 | ||
1150 | static void vga_arb_device_card_gone(struct pci_dev *pdev) | |
1151 | { | |
1152 | } | |
1153 | ||
1154 | /* | |
1155 | * callback any registered clients to let them know we have a | |
1156 | * change in VGA cards | |
1157 | */ | |
1158 | static void vga_arbiter_notify_clients(void) | |
1159 | { | |
1160 | struct vga_device *vgadev; | |
1161 | unsigned long flags; | |
1162 | uint32_t new_decodes; | |
1163 | bool new_state; | |
1164 | ||
1165 | if (!vga_arbiter_used) | |
1166 | return; | |
1167 | ||
1168 | spin_lock_irqsave(&vga_lock, flags); | |
1169 | list_for_each_entry(vgadev, &vga_list, list) { | |
1170 | if (vga_count > 1) | |
1171 | new_state = false; | |
1172 | else | |
1173 | new_state = true; | |
1174 | if (vgadev->set_vga_decode) { | |
1175 | new_decodes = vgadev->set_vga_decode(vgadev->cookie, new_state); | |
1176 | vga_update_device_decodes(vgadev, new_decodes); | |
1177 | } | |
1178 | } | |
1179 | spin_unlock_irqrestore(&vga_lock, flags); | |
1180 | } | |
1181 | ||
1182 | static int pci_notify(struct notifier_block *nb, unsigned long action, | |
1183 | void *data) | |
1184 | { | |
1185 | struct device *dev = data; | |
1186 | struct pci_dev *pdev = to_pci_dev(dev); | |
1187 | bool notify = false; | |
1188 | ||
2d6e9b91 | 1189 | pr_debug("%s\n", __func__); |
deb2d2ec BH |
1190 | |
1191 | /* For now we're only intereted in devices added and removed. I didn't | |
1192 | * test this thing here, so someone needs to double check for the | |
1193 | * cases of hotplugable vga cards. */ | |
1194 | if (action == BUS_NOTIFY_ADD_DEVICE) | |
1195 | notify = vga_arbiter_add_pci_device(pdev); | |
1196 | else if (action == BUS_NOTIFY_DEL_DEVICE) | |
1197 | notify = vga_arbiter_del_pci_device(pdev); | |
1198 | ||
1199 | if (notify) | |
1200 | vga_arbiter_notify_clients(); | |
1201 | return 0; | |
1202 | } | |
1203 | ||
1204 | static struct notifier_block pci_notifier = { | |
1205 | .notifier_call = pci_notify, | |
1206 | }; | |
1207 | ||
1208 | static const struct file_operations vga_arb_device_fops = { | |
1209 | .read = vga_arb_read, | |
1210 | .write = vga_arb_write, | |
1211 | .poll = vga_arb_fpoll, | |
1212 | .open = vga_arb_open, | |
1213 | .release = vga_arb_release, | |
1214 | }; | |
1215 | ||
1216 | static struct miscdevice vga_arb_device = { | |
1217 | MISC_DYNAMIC_MINOR, "vga_arbiter", &vga_arb_device_fops | |
1218 | }; | |
1219 | ||
1220 | static int __init vga_arb_device_init(void) | |
1221 | { | |
1222 | int rc; | |
1223 | struct pci_dev *pdev; | |
1224 | ||
1225 | rc = misc_register(&vga_arb_device); | |
1226 | if (rc < 0) | |
1227 | pr_err("vgaarb: error %d registering device\n", rc); | |
1228 | ||
1229 | bus_register_notifier(&pci_bus_type, &pci_notifier); | |
1230 | ||
1231 | /* We add all pci devices satisfying vga class in the arbiter by | |
1232 | * default */ | |
1233 | pdev = NULL; | |
1234 | while ((pdev = | |
1235 | pci_get_subsys(PCI_ANY_ID, PCI_ANY_ID, PCI_ANY_ID, | |
1236 | PCI_ANY_ID, pdev)) != NULL) | |
1237 | vga_arbiter_add_pci_device(pdev); | |
1238 | ||
1239 | pr_info("vgaarb: loaded\n"); | |
1240 | return rc; | |
1241 | } | |
1242 | subsys_initcall(vga_arb_device_init); |