Merge branch 'acpi-ec'
[linux-drm-fsl-dcu.git] / drivers / gpu / drm / vmwgfx / vmwgfx_fifo.c
1 /**************************************************************************
2  *
3  * Copyright © 2009 VMware, Inc., Palo Alto, CA., USA
4  * All Rights Reserved.
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a
7  * copy of this software and associated documentation files (the
8  * "Software"), to deal in the Software without restriction, including
9  * without limitation the rights to use, copy, modify, merge, publish,
10  * distribute, sub license, and/or sell copies of the Software, and to
11  * permit persons to whom the Software is furnished to do so, subject to
12  * the following conditions:
13  *
14  * The above copyright notice and this permission notice (including the
15  * next paragraph) shall be included in all copies or substantial portions
16  * of the Software.
17  *
18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
21  * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
22  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
23  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
24  * USE OR OTHER DEALINGS IN THE SOFTWARE.
25  *
26  **************************************************************************/
27
28 #include "vmwgfx_drv.h"
29 #include <drm/drmP.h>
30 #include <drm/ttm/ttm_placement.h>
31
32 bool vmw_fifo_have_3d(struct vmw_private *dev_priv)
33 {
34         __le32 __iomem *fifo_mem = dev_priv->mmio_virt;
35         uint32_t fifo_min, hwversion;
36         const struct vmw_fifo_state *fifo = &dev_priv->fifo;
37
38         if (!(dev_priv->capabilities & SVGA_CAP_3D))
39                 return false;
40
41         if (dev_priv->capabilities & SVGA_CAP_GBOBJECTS) {
42                 uint32_t result;
43
44                 if (!dev_priv->has_mob)
45                         return false;
46
47                 spin_lock(&dev_priv->cap_lock);
48                 vmw_write(dev_priv, SVGA_REG_DEV_CAP, SVGA3D_DEVCAP_3D);
49                 result = vmw_read(dev_priv, SVGA_REG_DEV_CAP);
50                 spin_unlock(&dev_priv->cap_lock);
51
52                 return (result != 0);
53         }
54
55         if (!(dev_priv->capabilities & SVGA_CAP_EXTENDED_FIFO))
56                 return false;
57
58         fifo_min = ioread32(fifo_mem  + SVGA_FIFO_MIN);
59         if (fifo_min <= SVGA_FIFO_3D_HWVERSION * sizeof(unsigned int))
60                 return false;
61
62         hwversion = ioread32(fifo_mem +
63                              ((fifo->capabilities &
64                                SVGA_FIFO_CAP_3D_HWVERSION_REVISED) ?
65                               SVGA_FIFO_3D_HWVERSION_REVISED :
66                               SVGA_FIFO_3D_HWVERSION));
67
68         if (hwversion == 0)
69                 return false;
70
71         if (hwversion < SVGA3D_HWVERSION_WS8_B1)
72                 return false;
73
74         /* Non-Screen Object path does not support surfaces */
75         if (!dev_priv->sou_priv)
76                 return false;
77
78         return true;
79 }
80
81 bool vmw_fifo_have_pitchlock(struct vmw_private *dev_priv)
82 {
83         __le32 __iomem *fifo_mem = dev_priv->mmio_virt;
84         uint32_t caps;
85
86         if (!(dev_priv->capabilities & SVGA_CAP_EXTENDED_FIFO))
87                 return false;
88
89         caps = ioread32(fifo_mem + SVGA_FIFO_CAPABILITIES);
90         if (caps & SVGA_FIFO_CAP_PITCHLOCK)
91                 return true;
92
93         return false;
94 }
95
96 int vmw_fifo_init(struct vmw_private *dev_priv, struct vmw_fifo_state *fifo)
97 {
98         __le32 __iomem *fifo_mem = dev_priv->mmio_virt;
99         uint32_t max;
100         uint32_t min;
101         uint32_t dummy;
102
103         fifo->static_buffer_size = VMWGFX_FIFO_STATIC_SIZE;
104         fifo->static_buffer = vmalloc(fifo->static_buffer_size);
105         if (unlikely(fifo->static_buffer == NULL))
106                 return -ENOMEM;
107
108         fifo->dynamic_buffer = NULL;
109         fifo->reserved_size = 0;
110         fifo->using_bounce_buffer = false;
111
112         mutex_init(&fifo->fifo_mutex);
113         init_rwsem(&fifo->rwsem);
114
115         /*
116          * Allow mapping the first page read-only to user-space.
117          */
118
119         DRM_INFO("width %d\n", vmw_read(dev_priv, SVGA_REG_WIDTH));
120         DRM_INFO("height %d\n", vmw_read(dev_priv, SVGA_REG_HEIGHT));
121         DRM_INFO("bpp %d\n", vmw_read(dev_priv, SVGA_REG_BITS_PER_PIXEL));
122
123         dev_priv->enable_state = vmw_read(dev_priv, SVGA_REG_ENABLE);
124         dev_priv->config_done_state = vmw_read(dev_priv, SVGA_REG_CONFIG_DONE);
125         dev_priv->traces_state = vmw_read(dev_priv, SVGA_REG_TRACES);
126         vmw_write(dev_priv, SVGA_REG_ENABLE, 1);
127
128         min = 4;
129         if (dev_priv->capabilities & SVGA_CAP_EXTENDED_FIFO)
130                 min = vmw_read(dev_priv, SVGA_REG_MEM_REGS);
131         min <<= 2;
132
133         if (min < PAGE_SIZE)
134                 min = PAGE_SIZE;
135
136         iowrite32(min, fifo_mem + SVGA_FIFO_MIN);
137         iowrite32(dev_priv->mmio_size, fifo_mem + SVGA_FIFO_MAX);
138         wmb();
139         iowrite32(min,  fifo_mem + SVGA_FIFO_NEXT_CMD);
140         iowrite32(min,  fifo_mem + SVGA_FIFO_STOP);
141         iowrite32(0, fifo_mem + SVGA_FIFO_BUSY);
142         mb();
143
144         vmw_write(dev_priv, SVGA_REG_CONFIG_DONE, 1);
145
146         max = ioread32(fifo_mem + SVGA_FIFO_MAX);
147         min = ioread32(fifo_mem  + SVGA_FIFO_MIN);
148         fifo->capabilities = ioread32(fifo_mem + SVGA_FIFO_CAPABILITIES);
149
150         DRM_INFO("Fifo max 0x%08x min 0x%08x cap 0x%08x\n",
151                  (unsigned int) max,
152                  (unsigned int) min,
153                  (unsigned int) fifo->capabilities);
154
155         atomic_set(&dev_priv->marker_seq, dev_priv->last_read_seqno);
156         iowrite32(dev_priv->last_read_seqno, fifo_mem + SVGA_FIFO_FENCE);
157         vmw_marker_queue_init(&fifo->marker_queue);
158         return vmw_fifo_send_fence(dev_priv, &dummy);
159 }
160
161 void vmw_fifo_ping_host(struct vmw_private *dev_priv, uint32_t reason)
162 {
163         __le32 __iomem *fifo_mem = dev_priv->mmio_virt;
164         static DEFINE_SPINLOCK(ping_lock);
165         unsigned long irq_flags;
166
167         /*
168          * The ping_lock is needed because we don't have an atomic
169          * test-and-set of the SVGA_FIFO_BUSY register.
170          */
171         spin_lock_irqsave(&ping_lock, irq_flags);
172         if (unlikely(ioread32(fifo_mem + SVGA_FIFO_BUSY) == 0)) {
173                 iowrite32(1, fifo_mem + SVGA_FIFO_BUSY);
174                 vmw_write(dev_priv, SVGA_REG_SYNC, reason);
175         }
176         spin_unlock_irqrestore(&ping_lock, irq_flags);
177 }
178
179 void vmw_fifo_release(struct vmw_private *dev_priv, struct vmw_fifo_state *fifo)
180 {
181         __le32 __iomem *fifo_mem = dev_priv->mmio_virt;
182
183         vmw_write(dev_priv, SVGA_REG_SYNC, SVGA_SYNC_GENERIC);
184         while (vmw_read(dev_priv, SVGA_REG_BUSY) != 0)
185                 ;
186
187         dev_priv->last_read_seqno = ioread32(fifo_mem + SVGA_FIFO_FENCE);
188
189         vmw_write(dev_priv, SVGA_REG_CONFIG_DONE,
190                   dev_priv->config_done_state);
191         vmw_write(dev_priv, SVGA_REG_ENABLE,
192                   dev_priv->enable_state);
193         vmw_write(dev_priv, SVGA_REG_TRACES,
194                   dev_priv->traces_state);
195
196         vmw_marker_queue_takedown(&fifo->marker_queue);
197
198         if (likely(fifo->static_buffer != NULL)) {
199                 vfree(fifo->static_buffer);
200                 fifo->static_buffer = NULL;
201         }
202
203         if (likely(fifo->dynamic_buffer != NULL)) {
204                 vfree(fifo->dynamic_buffer);
205                 fifo->dynamic_buffer = NULL;
206         }
207 }
208
209 static bool vmw_fifo_is_full(struct vmw_private *dev_priv, uint32_t bytes)
210 {
211         __le32 __iomem *fifo_mem = dev_priv->mmio_virt;
212         uint32_t max = ioread32(fifo_mem + SVGA_FIFO_MAX);
213         uint32_t next_cmd = ioread32(fifo_mem + SVGA_FIFO_NEXT_CMD);
214         uint32_t min = ioread32(fifo_mem + SVGA_FIFO_MIN);
215         uint32_t stop = ioread32(fifo_mem + SVGA_FIFO_STOP);
216
217         return ((max - next_cmd) + (stop - min) <= bytes);
218 }
219
220 static int vmw_fifo_wait_noirq(struct vmw_private *dev_priv,
221                                uint32_t bytes, bool interruptible,
222                                unsigned long timeout)
223 {
224         int ret = 0;
225         unsigned long end_jiffies = jiffies + timeout;
226         DEFINE_WAIT(__wait);
227
228         DRM_INFO("Fifo wait noirq.\n");
229
230         for (;;) {
231                 prepare_to_wait(&dev_priv->fifo_queue, &__wait,
232                                 (interruptible) ?
233                                 TASK_INTERRUPTIBLE : TASK_UNINTERRUPTIBLE);
234                 if (!vmw_fifo_is_full(dev_priv, bytes))
235                         break;
236                 if (time_after_eq(jiffies, end_jiffies)) {
237                         ret = -EBUSY;
238                         DRM_ERROR("SVGA device lockup.\n");
239                         break;
240                 }
241                 schedule_timeout(1);
242                 if (interruptible && signal_pending(current)) {
243                         ret = -ERESTARTSYS;
244                         break;
245                 }
246         }
247         finish_wait(&dev_priv->fifo_queue, &__wait);
248         wake_up_all(&dev_priv->fifo_queue);
249         DRM_INFO("Fifo noirq exit.\n");
250         return ret;
251 }
252
253 static int vmw_fifo_wait(struct vmw_private *dev_priv,
254                          uint32_t bytes, bool interruptible,
255                          unsigned long timeout)
256 {
257         long ret = 1L;
258         unsigned long irq_flags;
259
260         if (likely(!vmw_fifo_is_full(dev_priv, bytes)))
261                 return 0;
262
263         vmw_fifo_ping_host(dev_priv, SVGA_SYNC_FIFOFULL);
264         if (!(dev_priv->capabilities & SVGA_CAP_IRQMASK))
265                 return vmw_fifo_wait_noirq(dev_priv, bytes,
266                                            interruptible, timeout);
267
268         spin_lock(&dev_priv->waiter_lock);
269         if (atomic_add_return(1, &dev_priv->fifo_queue_waiters) > 0) {
270                 spin_lock_irqsave(&dev_priv->irq_lock, irq_flags);
271                 outl(SVGA_IRQFLAG_FIFO_PROGRESS,
272                      dev_priv->io_start + VMWGFX_IRQSTATUS_PORT);
273                 dev_priv->irq_mask |= SVGA_IRQFLAG_FIFO_PROGRESS;
274                 vmw_write(dev_priv, SVGA_REG_IRQMASK, dev_priv->irq_mask);
275                 spin_unlock_irqrestore(&dev_priv->irq_lock, irq_flags);
276         }
277         spin_unlock(&dev_priv->waiter_lock);
278
279         if (interruptible)
280                 ret = wait_event_interruptible_timeout
281                     (dev_priv->fifo_queue,
282                      !vmw_fifo_is_full(dev_priv, bytes), timeout);
283         else
284                 ret = wait_event_timeout
285                     (dev_priv->fifo_queue,
286                      !vmw_fifo_is_full(dev_priv, bytes), timeout);
287
288         if (unlikely(ret == 0))
289                 ret = -EBUSY;
290         else if (likely(ret > 0))
291                 ret = 0;
292
293         spin_lock(&dev_priv->waiter_lock);
294         if (atomic_dec_and_test(&dev_priv->fifo_queue_waiters)) {
295                 spin_lock_irqsave(&dev_priv->irq_lock, irq_flags);
296                 dev_priv->irq_mask &= ~SVGA_IRQFLAG_FIFO_PROGRESS;
297                 vmw_write(dev_priv, SVGA_REG_IRQMASK, dev_priv->irq_mask);
298                 spin_unlock_irqrestore(&dev_priv->irq_lock, irq_flags);
299         }
300         spin_unlock(&dev_priv->waiter_lock);
301
302         return ret;
303 }
304
305 /**
306  * Reserve @bytes number of bytes in the fifo.
307  *
308  * This function will return NULL (error) on two conditions:
309  *  If it timeouts waiting for fifo space, or if @bytes is larger than the
310  *   available fifo space.
311  *
312  * Returns:
313  *   Pointer to the fifo, or null on error (possible hardware hang).
314  */
315 void *vmw_fifo_reserve(struct vmw_private *dev_priv, uint32_t bytes)
316 {
317         struct vmw_fifo_state *fifo_state = &dev_priv->fifo;
318         __le32 __iomem *fifo_mem = dev_priv->mmio_virt;
319         uint32_t max;
320         uint32_t min;
321         uint32_t next_cmd;
322         uint32_t reserveable = fifo_state->capabilities & SVGA_FIFO_CAP_RESERVE;
323         int ret;
324
325         mutex_lock(&fifo_state->fifo_mutex);
326         max = ioread32(fifo_mem + SVGA_FIFO_MAX);
327         min = ioread32(fifo_mem + SVGA_FIFO_MIN);
328         next_cmd = ioread32(fifo_mem + SVGA_FIFO_NEXT_CMD);
329
330         if (unlikely(bytes >= (max - min)))
331                 goto out_err;
332
333         BUG_ON(fifo_state->reserved_size != 0);
334         BUG_ON(fifo_state->dynamic_buffer != NULL);
335
336         fifo_state->reserved_size = bytes;
337
338         while (1) {
339                 uint32_t stop = ioread32(fifo_mem + SVGA_FIFO_STOP);
340                 bool need_bounce = false;
341                 bool reserve_in_place = false;
342
343                 if (next_cmd >= stop) {
344                         if (likely((next_cmd + bytes < max ||
345                                     (next_cmd + bytes == max && stop > min))))
346                                 reserve_in_place = true;
347
348                         else if (vmw_fifo_is_full(dev_priv, bytes)) {
349                                 ret = vmw_fifo_wait(dev_priv, bytes,
350                                                     false, 3 * HZ);
351                                 if (unlikely(ret != 0))
352                                         goto out_err;
353                         } else
354                                 need_bounce = true;
355
356                 } else {
357
358                         if (likely((next_cmd + bytes < stop)))
359                                 reserve_in_place = true;
360                         else {
361                                 ret = vmw_fifo_wait(dev_priv, bytes,
362                                                     false, 3 * HZ);
363                                 if (unlikely(ret != 0))
364                                         goto out_err;
365                         }
366                 }
367
368                 if (reserve_in_place) {
369                         if (reserveable || bytes <= sizeof(uint32_t)) {
370                                 fifo_state->using_bounce_buffer = false;
371
372                                 if (reserveable)
373                                         iowrite32(bytes, fifo_mem +
374                                                   SVGA_FIFO_RESERVED);
375                                 return fifo_mem + (next_cmd >> 2);
376                         } else {
377                                 need_bounce = true;
378                         }
379                 }
380
381                 if (need_bounce) {
382                         fifo_state->using_bounce_buffer = true;
383                         if (bytes < fifo_state->static_buffer_size)
384                                 return fifo_state->static_buffer;
385                         else {
386                                 fifo_state->dynamic_buffer = vmalloc(bytes);
387                                 return fifo_state->dynamic_buffer;
388                         }
389                 }
390         }
391 out_err:
392         fifo_state->reserved_size = 0;
393         mutex_unlock(&fifo_state->fifo_mutex);
394         return NULL;
395 }
396
397 static void vmw_fifo_res_copy(struct vmw_fifo_state *fifo_state,
398                               __le32 __iomem *fifo_mem,
399                               uint32_t next_cmd,
400                               uint32_t max, uint32_t min, uint32_t bytes)
401 {
402         uint32_t chunk_size = max - next_cmd;
403         uint32_t rest;
404         uint32_t *buffer = (fifo_state->dynamic_buffer != NULL) ?
405             fifo_state->dynamic_buffer : fifo_state->static_buffer;
406
407         if (bytes < chunk_size)
408                 chunk_size = bytes;
409
410         iowrite32(bytes, fifo_mem + SVGA_FIFO_RESERVED);
411         mb();
412         memcpy_toio(fifo_mem + (next_cmd >> 2), buffer, chunk_size);
413         rest = bytes - chunk_size;
414         if (rest)
415                 memcpy_toio(fifo_mem + (min >> 2), buffer + (chunk_size >> 2),
416                             rest);
417 }
418
419 static void vmw_fifo_slow_copy(struct vmw_fifo_state *fifo_state,
420                                __le32 __iomem *fifo_mem,
421                                uint32_t next_cmd,
422                                uint32_t max, uint32_t min, uint32_t bytes)
423 {
424         uint32_t *buffer = (fifo_state->dynamic_buffer != NULL) ?
425             fifo_state->dynamic_buffer : fifo_state->static_buffer;
426
427         while (bytes > 0) {
428                 iowrite32(*buffer++, fifo_mem + (next_cmd >> 2));
429                 next_cmd += sizeof(uint32_t);
430                 if (unlikely(next_cmd == max))
431                         next_cmd = min;
432                 mb();
433                 iowrite32(next_cmd, fifo_mem + SVGA_FIFO_NEXT_CMD);
434                 mb();
435                 bytes -= sizeof(uint32_t);
436         }
437 }
438
439 void vmw_fifo_commit(struct vmw_private *dev_priv, uint32_t bytes)
440 {
441         struct vmw_fifo_state *fifo_state = &dev_priv->fifo;
442         __le32 __iomem *fifo_mem = dev_priv->mmio_virt;
443         uint32_t next_cmd = ioread32(fifo_mem + SVGA_FIFO_NEXT_CMD);
444         uint32_t max = ioread32(fifo_mem + SVGA_FIFO_MAX);
445         uint32_t min = ioread32(fifo_mem + SVGA_FIFO_MIN);
446         bool reserveable = fifo_state->capabilities & SVGA_FIFO_CAP_RESERVE;
447
448         BUG_ON((bytes & 3) != 0);
449         BUG_ON(bytes > fifo_state->reserved_size);
450
451         fifo_state->reserved_size = 0;
452
453         if (fifo_state->using_bounce_buffer) {
454                 if (reserveable)
455                         vmw_fifo_res_copy(fifo_state, fifo_mem,
456                                           next_cmd, max, min, bytes);
457                 else
458                         vmw_fifo_slow_copy(fifo_state, fifo_mem,
459                                            next_cmd, max, min, bytes);
460
461                 if (fifo_state->dynamic_buffer) {
462                         vfree(fifo_state->dynamic_buffer);
463                         fifo_state->dynamic_buffer = NULL;
464                 }
465
466         }
467
468         down_write(&fifo_state->rwsem);
469         if (fifo_state->using_bounce_buffer || reserveable) {
470                 next_cmd += bytes;
471                 if (next_cmd >= max)
472                         next_cmd -= max - min;
473                 mb();
474                 iowrite32(next_cmd, fifo_mem + SVGA_FIFO_NEXT_CMD);
475         }
476
477         if (reserveable)
478                 iowrite32(0, fifo_mem + SVGA_FIFO_RESERVED);
479         mb();
480         up_write(&fifo_state->rwsem);
481         vmw_fifo_ping_host(dev_priv, SVGA_SYNC_GENERIC);
482         mutex_unlock(&fifo_state->fifo_mutex);
483 }
484
485 int vmw_fifo_send_fence(struct vmw_private *dev_priv, uint32_t *seqno)
486 {
487         struct vmw_fifo_state *fifo_state = &dev_priv->fifo;
488         struct svga_fifo_cmd_fence *cmd_fence;
489         void *fm;
490         int ret = 0;
491         uint32_t bytes = sizeof(__le32) + sizeof(*cmd_fence);
492
493         fm = vmw_fifo_reserve(dev_priv, bytes);
494         if (unlikely(fm == NULL)) {
495                 *seqno = atomic_read(&dev_priv->marker_seq);
496                 ret = -ENOMEM;
497                 (void)vmw_fallback_wait(dev_priv, false, true, *seqno,
498                                         false, 3*HZ);
499                 goto out_err;
500         }
501
502         do {
503                 *seqno = atomic_add_return(1, &dev_priv->marker_seq);
504         } while (*seqno == 0);
505
506         if (!(fifo_state->capabilities & SVGA_FIFO_CAP_FENCE)) {
507
508                 /*
509                  * Don't request hardware to send a fence. The
510                  * waiting code in vmwgfx_irq.c will emulate this.
511                  */
512
513                 vmw_fifo_commit(dev_priv, 0);
514                 return 0;
515         }
516
517         *(__le32 *) fm = cpu_to_le32(SVGA_CMD_FENCE);
518         cmd_fence = (struct svga_fifo_cmd_fence *)
519             ((unsigned long)fm + sizeof(__le32));
520
521         iowrite32(*seqno, &cmd_fence->fence);
522         vmw_fifo_commit(dev_priv, bytes);
523         (void) vmw_marker_push(&fifo_state->marker_queue, *seqno);
524         vmw_update_seqno(dev_priv, fifo_state);
525
526 out_err:
527         return ret;
528 }
529
530 /**
531  * vmw_fifo_emit_dummy_legacy_query - emits a dummy query to the fifo using
532  * legacy query commands.
533  *
534  * @dev_priv: The device private structure.
535  * @cid: The hardware context id used for the query.
536  *
537  * See the vmw_fifo_emit_dummy_query documentation.
538  */
539 static int vmw_fifo_emit_dummy_legacy_query(struct vmw_private *dev_priv,
540                                             uint32_t cid)
541 {
542         /*
543          * A query wait without a preceding query end will
544          * actually finish all queries for this cid
545          * without writing to the query result structure.
546          */
547
548         struct ttm_buffer_object *bo = dev_priv->dummy_query_bo;
549         struct {
550                 SVGA3dCmdHeader header;
551                 SVGA3dCmdWaitForQuery body;
552         } *cmd;
553
554         cmd = vmw_fifo_reserve(dev_priv, sizeof(*cmd));
555
556         if (unlikely(cmd == NULL)) {
557                 DRM_ERROR("Out of fifo space for dummy query.\n");
558                 return -ENOMEM;
559         }
560
561         cmd->header.id = SVGA_3D_CMD_WAIT_FOR_QUERY;
562         cmd->header.size = sizeof(cmd->body);
563         cmd->body.cid = cid;
564         cmd->body.type = SVGA3D_QUERYTYPE_OCCLUSION;
565
566         if (bo->mem.mem_type == TTM_PL_VRAM) {
567                 cmd->body.guestResult.gmrId = SVGA_GMR_FRAMEBUFFER;
568                 cmd->body.guestResult.offset = bo->offset;
569         } else {
570                 cmd->body.guestResult.gmrId = bo->mem.start;
571                 cmd->body.guestResult.offset = 0;
572         }
573
574         vmw_fifo_commit(dev_priv, sizeof(*cmd));
575
576         return 0;
577 }
578
579 /**
580  * vmw_fifo_emit_dummy_gb_query - emits a dummy query to the fifo using
581  * guest-backed resource query commands.
582  *
583  * @dev_priv: The device private structure.
584  * @cid: The hardware context id used for the query.
585  *
586  * See the vmw_fifo_emit_dummy_query documentation.
587  */
588 static int vmw_fifo_emit_dummy_gb_query(struct vmw_private *dev_priv,
589                                         uint32_t cid)
590 {
591         /*
592          * A query wait without a preceding query end will
593          * actually finish all queries for this cid
594          * without writing to the query result structure.
595          */
596
597         struct ttm_buffer_object *bo = dev_priv->dummy_query_bo;
598         struct {
599                 SVGA3dCmdHeader header;
600                 SVGA3dCmdWaitForGBQuery body;
601         } *cmd;
602
603         cmd = vmw_fifo_reserve(dev_priv, sizeof(*cmd));
604
605         if (unlikely(cmd == NULL)) {
606                 DRM_ERROR("Out of fifo space for dummy query.\n");
607                 return -ENOMEM;
608         }
609
610         cmd->header.id = SVGA_3D_CMD_WAIT_FOR_GB_QUERY;
611         cmd->header.size = sizeof(cmd->body);
612         cmd->body.cid = cid;
613         cmd->body.type = SVGA3D_QUERYTYPE_OCCLUSION;
614         BUG_ON(bo->mem.mem_type != VMW_PL_MOB);
615         cmd->body.mobid = bo->mem.start;
616         cmd->body.offset = 0;
617
618         vmw_fifo_commit(dev_priv, sizeof(*cmd));
619
620         return 0;
621 }
622
623
624 /**
625  * vmw_fifo_emit_dummy_gb_query - emits a dummy query to the fifo using
626  * appropriate resource query commands.
627  *
628  * @dev_priv: The device private structure.
629  * @cid: The hardware context id used for the query.
630  *
631  * This function is used to emit a dummy occlusion query with
632  * no primitives rendered between query begin and query end.
633  * It's used to provide a query barrier, in order to know that when
634  * this query is finished, all preceding queries are also finished.
635  *
636  * A Query results structure should have been initialized at the start
637  * of the dev_priv->dummy_query_bo buffer object. And that buffer object
638  * must also be either reserved or pinned when this function is called.
639  *
640  * Returns -ENOMEM on failure to reserve fifo space.
641  */
642 int vmw_fifo_emit_dummy_query(struct vmw_private *dev_priv,
643                               uint32_t cid)
644 {
645         if (dev_priv->has_mob)
646                 return vmw_fifo_emit_dummy_gb_query(dev_priv, cid);
647
648         return vmw_fifo_emit_dummy_legacy_query(dev_priv, cid);
649 }