1// SPDX-License-Identifier: GPL-2.0 OR MIT
2/**************************************************************************
3 *
4 * Copyright (c) 2024 Broadcom. All Rights Reserved. The term
5 * “Broadcom” refers to Broadcom Inc. and/or its subsidiaries.
6 *
7 * Permission is hereby granted, free of charge, to any person obtaining a
8 * copy of this software and associated documentation files (the
9 * "Software"), to deal in the Software without restriction, including
10 * without limitation the rights to use, copy, modify, merge, publish,
11 * distribute, sub license, and/or sell copies of the Software, and to
12 * permit persons to whom the Software is furnished to do so, subject to
13 * the following conditions:
14 *
15 * The above copyright notice and this permission notice (including the
16 * next paragraph) shall be included in all copies or substantial portions
17 * of the Software.
18 *
19 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
20 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
21 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
22 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
23 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
24 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
25 * USE OR OTHER DEALINGS IN THE SOFTWARE.
26 *
27 **************************************************************************/
28
29#include "vmwgfx_vkms.h"
30
31#include "vmwgfx_bo.h"
32#include "vmwgfx_drv.h"
33#include "vmwgfx_kms.h"
34
35#include "vmw_surface_cache.h"
36
37#include <drm/drm_crtc.h>
38#include <drm/drm_debugfs_crc.h>
39#include <drm/drm_print.h>
40#include <drm/drm_vblank.h>
41
42#include <linux/crc32.h>
43#include <linux/delay.h>
44
45#define GUESTINFO_VBLANK "guestinfo.vmwgfx.vkms_enable"
46
47static int
48vmw_surface_sync(struct vmw_private *vmw,
49 struct vmw_surface *surf)
50{
51 int ret;
52 struct vmw_fence_obj *fence = NULL;
53 struct vmw_bo *bo = surf->res.guest_memory_bo;
54
55 vmw_resource_clean(res: &surf->res);
56
57 ret = ttm_bo_reserve(bo: &bo->tbo, interruptible: false, no_wait: false, NULL);
58 if (ret != 0) {
59 drm_warn(&vmw->drm, "%s: failed reserve\n", __func__);
60 goto done;
61 }
62
63 ret = vmw_execbuf_fence_commands(NULL, dev_priv: vmw, p_fence: &fence, NULL);
64 if (ret != 0) {
65 drm_warn(&vmw->drm, "%s: failed execbuf\n", __func__);
66 ttm_bo_unreserve(bo: &bo->tbo);
67 goto done;
68 }
69
70 dma_fence_wait(fence: &fence->base, intr: false);
71 dma_fence_put(fence: &fence->base);
72
73 ttm_bo_unreserve(bo: &bo->tbo);
74done:
75 return ret;
76}
77
78static void
79compute_crc(struct drm_crtc *crtc,
80 struct vmw_surface *surf,
81 u32 *crc)
82{
83 u8 *mapped_surface;
84 struct vmw_bo *bo = surf->res.guest_memory_bo;
85 const struct SVGA3dSurfaceDesc *desc =
86 vmw_surface_get_desc(format: surf->metadata.format);
87 u32 row_pitch_bytes;
88 SVGA3dSize blocks;
89 u32 y;
90
91 *crc = 0;
92
93 vmw_surface_get_size_in_blocks(desc, pixel_size: &surf->metadata.base_size, block_size: &blocks);
94 row_pitch_bytes = blocks.width * desc->pitchBytesPerBlock;
95 WARN_ON(!bo);
96 mapped_surface = vmw_bo_map_and_cache(vbo: bo);
97
98 for (y = 0; y < blocks.height; y++) {
99 *crc = crc32_le(crc: *crc, p: mapped_surface, len: row_pitch_bytes);
100 mapped_surface += row_pitch_bytes;
101 }
102
103 vmw_bo_unmap(vbo: bo);
104}
105
106static void
107crc_generate_worker(struct work_struct *work)
108{
109 struct vmw_display_unit *du =
110 container_of(work, struct vmw_display_unit, vkms.crc_generator_work);
111 struct drm_crtc *crtc = &du->crtc;
112 struct vmw_private *vmw = vmw_priv(dev: crtc->dev);
113 bool crc_pending;
114 u64 frame_start, frame_end;
115 u32 crc32 = 0;
116 struct vmw_surface *surf = 0;
117
118 spin_lock_irq(lock: &du->vkms.crc_state_lock);
119 crc_pending = du->vkms.crc_pending;
120 spin_unlock_irq(lock: &du->vkms.crc_state_lock);
121
122 /*
123 * We raced with the vblank hrtimer and previous work already computed
124 * the crc, nothing to do.
125 */
126 if (!crc_pending)
127 return;
128
129 spin_lock_irq(lock: &du->vkms.crc_state_lock);
130 surf = vmw_surface_reference(srf: du->vkms.surface);
131 spin_unlock_irq(lock: &du->vkms.crc_state_lock);
132
133 if (surf) {
134 if (vmw_surface_sync(vmw, surf)) {
135 drm_warn(
136 crtc->dev,
137 "CRC worker wasn't able to sync the crc surface!\n");
138 return;
139 }
140
141 compute_crc(crtc, surf, crc: &crc32);
142 vmw_surface_unreference(srf: &surf);
143 }
144
145 spin_lock_irq(lock: &du->vkms.crc_state_lock);
146 frame_start = du->vkms.frame_start;
147 frame_end = du->vkms.frame_end;
148 du->vkms.frame_start = 0;
149 du->vkms.frame_end = 0;
150 du->vkms.crc_pending = false;
151 spin_unlock_irq(lock: &du->vkms.crc_state_lock);
152
153 /*
154 * The worker can fall behind the vblank hrtimer, make sure we catch up.
155 */
156 while (frame_start <= frame_end)
157 drm_crtc_add_crc_entry(crtc, has_frame: true, frame: frame_start++, crcs: &crc32);
158}
159
160static enum hrtimer_restart
161vmw_vkms_vblank_simulate(struct hrtimer *timer)
162{
163 struct vmw_display_unit *du = container_of(timer, struct vmw_display_unit, vkms.timer);
164 struct drm_crtc *crtc = &du->crtc;
165 struct vmw_private *vmw = vmw_priv(dev: crtc->dev);
166 bool has_surface = false;
167 u64 ret_overrun;
168 bool locked, ret;
169
170 ret_overrun = hrtimer_forward_now(timer: &du->vkms.timer,
171 interval: du->vkms.period_ns);
172 if (ret_overrun != 1)
173 drm_dbg_driver(crtc->dev, "vblank timer missed %lld frames.\n",
174 ret_overrun - 1);
175
176 locked = vmw_vkms_vblank_trylock(crtc);
177 ret = drm_crtc_handle_vblank(crtc);
178 WARN_ON(!ret);
179 if (!locked)
180 return HRTIMER_RESTART;
181 has_surface = du->vkms.surface != NULL;
182 vmw_vkms_unlock(crtc);
183
184 if (du->vkms.crc_enabled && has_surface) {
185 u64 frame = drm_crtc_accurate_vblank_count(crtc);
186
187 spin_lock(lock: &du->vkms.crc_state_lock);
188 if (!du->vkms.crc_pending)
189 du->vkms.frame_start = frame;
190 else
191 drm_dbg_driver(crtc->dev,
192 "crc worker falling behind, frame_start: %llu, frame_end: %llu\n",
193 du->vkms.frame_start, frame);
194 du->vkms.frame_end = frame;
195 du->vkms.crc_pending = true;
196 spin_unlock(lock: &du->vkms.crc_state_lock);
197
198 ret = queue_work(wq: vmw->crc_workq, work: &du->vkms.crc_generator_work);
199 if (!ret)
200 drm_dbg_driver(crtc->dev, "Composer worker already queued\n");
201 }
202
203 return HRTIMER_RESTART;
204}
205
206void
207vmw_vkms_init(struct vmw_private *vmw)
208{
209 char buffer[64];
210 const size_t max_buf_len = sizeof(buffer) - 1;
211 size_t buf_len = max_buf_len;
212 int ret;
213
214 vmw->vkms_enabled = false;
215
216 ret = vmw_host_get_guestinfo(GUESTINFO_VBLANK, buffer, length: &buf_len);
217 if (ret || buf_len > max_buf_len)
218 return;
219 buffer[buf_len] = '\0';
220
221 ret = kstrtobool(s: buffer, res: &vmw->vkms_enabled);
222 if (!ret && vmw->vkms_enabled) {
223 ret = drm_vblank_init(dev: &vmw->drm, VMWGFX_NUM_DISPLAY_UNITS);
224 vmw->vkms_enabled = (ret == 0);
225 }
226
227 vmw->crc_workq = alloc_ordered_workqueue("vmwgfx_crc_generator", 0);
228 if (!vmw->crc_workq) {
229 drm_warn(&vmw->drm, "crc workqueue allocation failed. Disabling vkms.");
230 vmw->vkms_enabled = false;
231 }
232 if (vmw->vkms_enabled)
233 drm_info(&vmw->drm, "VKMS enabled\n");
234}
235
236void
237vmw_vkms_cleanup(struct vmw_private *vmw)
238{
239 destroy_workqueue(wq: vmw->crc_workq);
240}
241
242bool
243vmw_vkms_get_vblank_timestamp(struct drm_crtc *crtc,
244 int *max_error,
245 ktime_t *vblank_time,
246 bool in_vblank_irq)
247{
248 struct drm_device *dev = crtc->dev;
249 struct vmw_private *vmw = vmw_priv(dev);
250 struct vmw_display_unit *du = vmw_crtc_to_du(crtc);
251 struct drm_vblank_crtc *vblank = drm_crtc_vblank_crtc(crtc);
252
253 if (!vmw->vkms_enabled)
254 return false;
255
256 if (!READ_ONCE(vblank->enabled)) {
257 *vblank_time = ktime_get();
258 return true;
259 }
260
261 *vblank_time = READ_ONCE(du->vkms.timer.node.expires);
262
263 if (WARN_ON(*vblank_time == vblank->time))
264 return true;
265
266 /*
267 * To prevent races we roll the hrtimer forward before we do any
268 * interrupt processing - this is how real hw works (the interrupt is
269 * only generated after all the vblank registers are updated) and what
270 * the vblank core expects. Therefore we need to always correct the
271 * timestampe by one frame.
272 */
273 *vblank_time -= du->vkms.period_ns;
274
275 return true;
276}
277
278int
279vmw_vkms_enable_vblank(struct drm_crtc *crtc)
280{
281 struct drm_device *dev = crtc->dev;
282 struct vmw_private *vmw = vmw_priv(dev);
283 struct drm_vblank_crtc *vblank = drm_crtc_vblank_crtc(crtc);
284 struct vmw_display_unit *du = vmw_crtc_to_du(crtc);
285
286 if (!vmw->vkms_enabled)
287 return -EINVAL;
288
289 drm_calc_timestamping_constants(crtc, mode: &crtc->mode);
290
291 hrtimer_setup(timer: &du->vkms.timer, function: &vmw_vkms_vblank_simulate, CLOCK_MONOTONIC,
292 mode: HRTIMER_MODE_REL);
293 du->vkms.period_ns = ktime_set(secs: 0, nsecs: vblank->framedur_ns);
294 hrtimer_start(timer: &du->vkms.timer, tim: du->vkms.period_ns, mode: HRTIMER_MODE_REL);
295
296 return 0;
297}
298
299void
300vmw_vkms_disable_vblank(struct drm_crtc *crtc)
301{
302 struct vmw_display_unit *du = vmw_crtc_to_du(crtc);
303 struct vmw_private *vmw = vmw_priv(dev: crtc->dev);
304
305 if (!vmw->vkms_enabled)
306 return;
307
308 hrtimer_cancel(timer: &du->vkms.timer);
309 du->vkms.surface = NULL;
310 du->vkms.period_ns = ktime_set(secs: 0, nsecs: 0);
311}
312
313enum vmw_vkms_lock_state {
314 VMW_VKMS_LOCK_UNLOCKED = 0,
315 VMW_VKMS_LOCK_MODESET = 1,
316 VMW_VKMS_LOCK_VBLANK = 2
317};
318
319void
320vmw_vkms_crtc_init(struct drm_crtc *crtc)
321{
322 struct vmw_display_unit *du = vmw_crtc_to_du(crtc);
323
324 atomic_set(v: &du->vkms.atomic_lock, i: VMW_VKMS_LOCK_UNLOCKED);
325 spin_lock_init(&du->vkms.crc_state_lock);
326
327 INIT_WORK(&du->vkms.crc_generator_work, crc_generate_worker);
328 du->vkms.surface = NULL;
329}
330
331void
332vmw_vkms_crtc_cleanup(struct drm_crtc *crtc)
333{
334 struct vmw_display_unit *du = vmw_crtc_to_du(crtc);
335
336 if (du->vkms.surface)
337 vmw_surface_unreference(srf: &du->vkms.surface);
338 WARN_ON(work_pending(&du->vkms.crc_generator_work));
339 hrtimer_cancel(timer: &du->vkms.timer);
340}
341
342void
343vmw_vkms_crtc_atomic_begin(struct drm_crtc *crtc,
344 struct drm_atomic_state *state)
345{
346 struct vmw_private *vmw = vmw_priv(dev: crtc->dev);
347
348 if (vmw->vkms_enabled)
349 vmw_vkms_modeset_lock(crtc);
350}
351
352void
353vmw_vkms_crtc_atomic_flush(struct drm_crtc *crtc,
354 struct drm_atomic_state *state)
355{
356 unsigned long flags;
357 struct vmw_private *vmw = vmw_priv(dev: crtc->dev);
358
359 if (!vmw->vkms_enabled)
360 return;
361
362 if (crtc->state->event) {
363 spin_lock_irqsave(&crtc->dev->event_lock, flags);
364
365 if (drm_crtc_vblank_get(crtc) != 0)
366 drm_crtc_send_vblank_event(crtc, e: crtc->state->event);
367 else
368 drm_crtc_arm_vblank_event(crtc, e: crtc->state->event);
369
370 spin_unlock_irqrestore(lock: &crtc->dev->event_lock, flags);
371
372 crtc->state->event = NULL;
373 }
374
375 vmw_vkms_unlock(crtc);
376}
377
378void
379vmw_vkms_crtc_atomic_enable(struct drm_crtc *crtc,
380 struct drm_atomic_state *state)
381{
382 struct vmw_private *vmw = vmw_priv(dev: crtc->dev);
383
384 if (vmw->vkms_enabled)
385 drm_crtc_vblank_on(crtc);
386}
387
388void
389vmw_vkms_crtc_atomic_disable(struct drm_crtc *crtc,
390 struct drm_atomic_state *state)
391{
392 struct vmw_private *vmw = vmw_priv(dev: crtc->dev);
393
394 if (vmw->vkms_enabled)
395 drm_crtc_vblank_off(crtc);
396}
397
398static bool
399is_crc_supported(struct drm_crtc *crtc)
400{
401 struct vmw_private *vmw = vmw_priv(dev: crtc->dev);
402
403 if (!vmw->vkms_enabled)
404 return false;
405
406 if (vmw->active_display_unit != vmw_du_screen_target)
407 return false;
408
409 return true;
410}
411
412static const char * const pipe_crc_sources[] = {"auto"};
413
414static int
415crc_parse_source(const char *src_name,
416 bool *enabled)
417{
418 int ret = 0;
419
420 if (!src_name) {
421 *enabled = false;
422 } else if (strcmp(src_name, "auto") == 0) {
423 *enabled = true;
424 } else {
425 *enabled = false;
426 ret = -EINVAL;
427 }
428
429 return ret;
430}
431
432const char *const *
433vmw_vkms_get_crc_sources(struct drm_crtc *crtc,
434 size_t *count)
435{
436 *count = 0;
437 if (!is_crc_supported(crtc))
438 return NULL;
439
440 *count = ARRAY_SIZE(pipe_crc_sources);
441 return pipe_crc_sources;
442}
443
444int
445vmw_vkms_verify_crc_source(struct drm_crtc *crtc,
446 const char *src_name,
447 size_t *values_cnt)
448{
449 bool enabled;
450
451 if (!is_crc_supported(crtc))
452 return -EINVAL;
453
454 if (crc_parse_source(src_name, enabled: &enabled) < 0) {
455 drm_dbg_driver(crtc->dev, "unknown source '%s'\n", src_name);
456 return -EINVAL;
457 }
458
459 *values_cnt = 1;
460
461 return 0;
462}
463
464int
465vmw_vkms_set_crc_source(struct drm_crtc *crtc,
466 const char *src_name)
467{
468 struct vmw_display_unit *du = vmw_crtc_to_du(crtc);
469 bool enabled, prev_enabled, locked;
470 int ret;
471
472 if (!is_crc_supported(crtc))
473 return -EINVAL;
474
475 ret = crc_parse_source(src_name, enabled: &enabled);
476
477 if (enabled)
478 drm_crtc_vblank_get(crtc);
479
480 locked = vmw_vkms_modeset_lock_relaxed(crtc);
481 prev_enabled = du->vkms.crc_enabled;
482 du->vkms.crc_enabled = enabled;
483 if (locked)
484 vmw_vkms_unlock(crtc);
485
486 if (prev_enabled)
487 drm_crtc_vblank_put(crtc);
488
489 return ret;
490}
491
492void
493vmw_vkms_set_crc_surface(struct drm_crtc *crtc,
494 struct vmw_surface *surf)
495{
496 struct vmw_display_unit *du = vmw_crtc_to_du(crtc);
497 struct vmw_private *vmw = vmw_priv(dev: crtc->dev);
498
499 if (vmw->vkms_enabled && du->vkms.surface != surf) {
500 WARN_ON(atomic_read(&du->vkms.atomic_lock) != VMW_VKMS_LOCK_MODESET);
501 if (du->vkms.surface)
502 vmw_surface_unreference(srf: &du->vkms.surface);
503 if (surf)
504 du->vkms.surface = vmw_surface_reference(srf: surf);
505 }
506}
507
508/**
509 * vmw_vkms_lock_max_wait_ns - Return the max wait for the vkms lock
510 * @du: The vmw_display_unit from which to grab the vblank timings
511 *
512 * Returns the maximum wait time used to acquire the vkms lock. By
513 * default uses a time of a single frame and in case where vblank
514 * was not initialized for the display unit 1/60th of a second.
515 */
516static inline u64
517vmw_vkms_lock_max_wait_ns(struct vmw_display_unit *du)
518{
519 s64 nsecs = ktime_to_ns(kt: du->vkms.period_ns);
520
521 return (nsecs > 0) ? nsecs : 16666666;
522}
523
524/**
525 * vmw_vkms_modeset_lock - Protects access to crtc during modeset
526 * @crtc: The crtc to lock for vkms
527 *
528 * This function prevents the VKMS timers/callbacks from being called
529 * while a modeset operation is in process. We don't want the callbacks
530 * e.g. the vblank simulator to be trying to access incomplete state
531 * so we need to make sure they execute only when the modeset has
532 * finished.
533 *
534 * Normally this would have been done with a spinlock but locking the
535 * entire atomic modeset with vmwgfx is impossible because kms prepare
536 * executes non-atomic ops (e.g. vmw_validation_prepare holds a mutex to
537 * guard various bits of state). Which means that we need to synchronize
538 * atomic context (the vblank handler) with the non-atomic entirity
539 * of kms - so use an atomic_t to track which part of vkms has access
540 * to the basic vkms state.
541 */
542void
543vmw_vkms_modeset_lock(struct drm_crtc *crtc)
544{
545 struct vmw_display_unit *du = vmw_crtc_to_du(crtc);
546 const u64 nsecs_delay = 10;
547 const u64 MAX_NSECS_DELAY = vmw_vkms_lock_max_wait_ns(du);
548 u64 total_delay = 0;
549 int ret;
550
551 do {
552 ret = atomic_cmpxchg(v: &du->vkms.atomic_lock,
553 old: VMW_VKMS_LOCK_UNLOCKED,
554 new: VMW_VKMS_LOCK_MODESET);
555 if (ret == VMW_VKMS_LOCK_UNLOCKED || total_delay >= MAX_NSECS_DELAY)
556 break;
557 ndelay(nsecs_delay);
558 total_delay += nsecs_delay;
559 } while (1);
560
561 if (total_delay >= MAX_NSECS_DELAY) {
562 drm_warn(crtc->dev, "VKMS lock expired! total_delay = %lld, ret = %d, cur = %d\n",
563 total_delay, ret, atomic_read(&du->vkms.atomic_lock));
564 }
565}
566
567/**
568 * vmw_vkms_modeset_lock_relaxed - Protects access to crtc during modeset
569 * @crtc: The crtc to lock for vkms
570 *
571 * Much like vmw_vkms_modeset_lock except that when the crtc is currently
572 * in a modeset it will return immediately.
573 *
574 * Returns true if actually locked vkms to modeset or false otherwise.
575 */
576bool
577vmw_vkms_modeset_lock_relaxed(struct drm_crtc *crtc)
578{
579 struct vmw_display_unit *du = vmw_crtc_to_du(crtc);
580 const u64 nsecs_delay = 10;
581 const u64 MAX_NSECS_DELAY = vmw_vkms_lock_max_wait_ns(du);
582 u64 total_delay = 0;
583 int ret;
584
585 do {
586 ret = atomic_cmpxchg(v: &du->vkms.atomic_lock,
587 old: VMW_VKMS_LOCK_UNLOCKED,
588 new: VMW_VKMS_LOCK_MODESET);
589 if (ret == VMW_VKMS_LOCK_UNLOCKED ||
590 ret == VMW_VKMS_LOCK_MODESET ||
591 total_delay >= MAX_NSECS_DELAY)
592 break;
593 ndelay(nsecs_delay);
594 total_delay += nsecs_delay;
595 } while (1);
596
597 if (total_delay >= MAX_NSECS_DELAY) {
598 drm_warn(crtc->dev, "VKMS relaxed lock expired!\n");
599 return false;
600 }
601
602 return ret == VMW_VKMS_LOCK_UNLOCKED;
603}
604
605/**
606 * vmw_vkms_vblank_trylock - Protects access to crtc during vblank
607 * @crtc: The crtc to lock for vkms
608 *
609 * Tries to lock vkms for vblank, returns immediately.
610 *
611 * Returns true if locked vkms to vblank or false otherwise.
612 */
613bool
614vmw_vkms_vblank_trylock(struct drm_crtc *crtc)
615{
616 struct vmw_display_unit *du = vmw_crtc_to_du(crtc);
617 u32 ret;
618
619 ret = atomic_cmpxchg(v: &du->vkms.atomic_lock,
620 old: VMW_VKMS_LOCK_UNLOCKED,
621 new: VMW_VKMS_LOCK_VBLANK);
622
623 return ret == VMW_VKMS_LOCK_UNLOCKED;
624}
625
626void
627vmw_vkms_unlock(struct drm_crtc *crtc)
628{
629 struct vmw_display_unit *du = vmw_crtc_to_du(crtc);
630
631 /* Release flag; mark it as unlocked. */
632 atomic_set(v: &du->vkms.atomic_lock, i: VMW_VKMS_LOCK_UNLOCKED);
633}
634

source code of linux/drivers/gpu/drm/vmwgfx/vmwgfx_vkms.c