2 * Copyright © 2008 Intel Corporation
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
24 * Eric Anholt <eric@anholt.net>
28 /** @file brw_queryobj.c
30 * Support for query objects (GL_ARB_occlusion_query, GL_ARB_timer_query,
31 * GL_EXT_transform_feedback, and friends).
33 * The hardware provides a PIPE_CONTROL command that can report the number of
34 * fragments that passed the depth test, or the hardware timer. They are
35 * appropriately synced with the stage of the pipeline for our extensions'
38 #include "main/imports.h"
40 #include "brw_context.h"
41 #include "brw_defines.h"
42 #include "brw_state.h"
43 #include "intel_batchbuffer.h"
44 #include "intel_reg.h"
47 * Emit PIPE_CONTROLs to write the current GPU timestamp into a buffer.
50 write_timestamp(struct intel_context *intel, drm_intel_bo *query_bo, int idx)
52 if (intel->gen >= 6) {
53 /* Emit workaround flushes: */
54 if (intel->gen == 6) {
55 /* The timestamp write below is a non-zero post-sync op, which on
56 * Gen6 necessitates a CS stall. CS stalls need stall at scoreboard
57 * set. See the comments for intel_emit_post_sync_nonzero_flush().
60 OUT_BATCH(_3DSTATE_PIPE_CONTROL | (4 - 2));
61 OUT_BATCH(PIPE_CONTROL_CS_STALL | PIPE_CONTROL_STALL_AT_SCOREBOARD);
68 OUT_BATCH(_3DSTATE_PIPE_CONTROL | (5 - 2));
69 OUT_BATCH(PIPE_CONTROL_WRITE_TIMESTAMP);
71 I915_GEM_DOMAIN_INSTRUCTION, I915_GEM_DOMAIN_INSTRUCTION,
72 PIPE_CONTROL_GLOBAL_GTT_WRITE |
73 idx * sizeof(uint64_t));
79 OUT_BATCH(_3DSTATE_PIPE_CONTROL | (4 - 2) |
80 PIPE_CONTROL_WRITE_TIMESTAMP);
82 I915_GEM_DOMAIN_INSTRUCTION, I915_GEM_DOMAIN_INSTRUCTION,
83 PIPE_CONTROL_GLOBAL_GTT_WRITE |
84 idx * sizeof(uint64_t));
92 * Emit PIPE_CONTROLs to write the PS_DEPTH_COUNT register into a buffer.
95 write_depth_count(struct intel_context *intel, drm_intel_bo *query_bo, int idx)
97 assert(intel->gen < 6);
100 OUT_BATCH(_3DSTATE_PIPE_CONTROL | (4 - 2) |
101 PIPE_CONTROL_DEPTH_STALL | PIPE_CONTROL_WRITE_DEPTH_COUNT);
102 /* This object could be mapped cacheable, but we don't have an exposed
103 * mechanism to support that. Since it's going uncached, tell GEM that
104 * we're writing to it. The usual clflush should be all that's required
105 * to pick up the results.
108 I915_GEM_DOMAIN_INSTRUCTION, I915_GEM_DOMAIN_INSTRUCTION,
109 PIPE_CONTROL_GLOBAL_GTT_WRITE |
110 (idx * sizeof(uint64_t)));
117 * Wait on the query object's BO and calculate the final result.
120 brw_queryobj_get_results(struct gl_context *ctx,
121 struct brw_query_object *query)
123 struct intel_context *intel = intel_context(ctx);
128 assert(intel->gen < 6);
130 if (query->bo == NULL)
133 /* If the application has requested the query result, but this batch is
134 * still contributing to it, flush it now so the results will be present
137 if (drm_intel_bo_references(intel->batch.bo, query->bo))
138 intel_batchbuffer_flush(intel);
140 if (unlikely(intel->perf_debug)) {
141 if (drm_intel_bo_busy(query->bo)) {
142 perf_debug("Stalling on the GPU waiting for a query object.\n");
146 drm_intel_bo_map(query->bo, false);
147 results = query->bo->virtual;
148 switch (query->Base.Target) {
149 case GL_TIME_ELAPSED_EXT:
150 /* The query BO contains the starting and ending timestamps.
151 * Subtract the two and convert to nanoseconds.
153 query->Base.Result += 1000 * ((results[1] >> 32) - (results[0] >> 32));
157 /* The query BO contains a single timestamp value in results[0]. */
158 query->Base.Result = 1000 * (results[0] >> 32);
161 case GL_SAMPLES_PASSED_ARB:
162 /* Loop over pairs of values from the BO, which are the PS_DEPTH_COUNT
163 * value at the start and end of the batchbuffer. Subtract them to
164 * get the number of fragments which passed the depth test in each
165 * individual batch, and add those differences up to get the number
166 * of fragments for the entire query.
168 * Note that query->Base.Result may already be non-zero. We may have
169 * run out of space in the query's BO and allocated a new one. If so,
170 * this function was already called to accumulate the results so far.
172 for (i = 0; i < query->last_index; i++) {
173 query->Base.Result += results[i * 2 + 1] - results[i * 2];
177 case GL_ANY_SAMPLES_PASSED:
178 case GL_ANY_SAMPLES_PASSED_CONSERVATIVE:
179 /* If the starting and ending PS_DEPTH_COUNT from any of the batches
180 * differ, then some fragments passed the depth test.
182 for (i = 0; i < query->last_index; i++) {
183 if (results[i * 2 + 1] != results[i * 2]) {
184 query->Base.Result = GL_TRUE;
191 assert(!"Unrecognized query target in brw_queryobj_get_results()");
194 drm_intel_bo_unmap(query->bo);
196 /* Now that we've processed the data stored in the query's buffer object,
199 drm_intel_bo_unreference(query->bo);
204 * The NewQueryObject() driver hook.
206 * Allocates and initializes a new query object.
208 static struct gl_query_object *
209 brw_new_query_object(struct gl_context *ctx, GLuint id)
211 struct brw_query_object *query;
213 query = calloc(1, sizeof(struct brw_query_object));
216 query->Base.Result = 0;
217 query->Base.Active = false;
218 query->Base.Ready = true;
224 * The DeleteQuery() driver hook.
227 brw_delete_query(struct gl_context *ctx, struct gl_query_object *q)
229 struct brw_query_object *query = (struct brw_query_object *)q;
231 drm_intel_bo_unreference(query->bo);
236 * Gen4-5 driver hook for glBeginQuery().
238 * Initializes driver structures and emits any GPU commands required to begin
239 * recording data for the query.
242 brw_begin_query(struct gl_context *ctx, struct gl_query_object *q)
244 struct brw_context *brw = brw_context(ctx);
245 struct intel_context *intel = intel_context(ctx);
246 struct brw_query_object *query = (struct brw_query_object *)q;
248 assert(intel->gen < 6);
250 switch (query->Base.Target) {
251 case GL_TIME_ELAPSED_EXT:
252 /* For timestamp queries, we record the starting time right away so that
253 * we measure the full time between BeginQuery and EndQuery. There's
254 * some debate about whether this is the right thing to do. Our decision
255 * is based on the following text from the ARB_timer_query extension:
257 * "(5) Should the extension measure total time elapsed between the full
258 * completion of the BeginQuery and EndQuery commands, or just time
259 * spent in the graphics library?
261 * RESOLVED: This extension will measure the total time elapsed
262 * between the full completion of these commands. Future extensions
263 * may implement a query to determine time elapsed at different stages
264 * of the graphics pipeline."
266 * We write a starting timestamp now (at index 0). At EndQuery() time,
267 * we'll write a second timestamp (at index 1), and subtract the two to
268 * obtain the time elapsed. Notably, this includes time elapsed while
269 * the system was doing other work, such as running other applications.
271 drm_intel_bo_unreference(query->bo);
272 query->bo = drm_intel_bo_alloc(intel->bufmgr, "timer query", 4096, 4096);
273 write_timestamp(intel, query->bo, 0);
276 case GL_ANY_SAMPLES_PASSED:
277 case GL_ANY_SAMPLES_PASSED_CONSERVATIVE:
278 case GL_SAMPLES_PASSED_ARB:
279 /* For occlusion queries, we delay taking an initial sample until the
280 * first drawing occurs in this batch. See the reasoning in the comments
281 * for brw_emit_query_begin() below.
283 * Since we're starting a new query, we need to be sure to throw away
284 * any previous occlusion query results.
286 drm_intel_bo_unreference(query->bo);
288 query->last_index = -1;
290 brw->query.obj = query;
292 /* Depth statistics on Gen4 require strange workarounds, so we try to
293 * avoid them when necessary. They're required for occlusion queries,
294 * so turn them on now.
297 brw->state.dirty.brw |= BRW_NEW_STATS_WM;
301 assert(!"Unrecognized query target in brw_begin_query()");
307 * Gen4-5 driver hook for glEndQuery().
309 * Emits GPU commands to record a final query value, ending any data capturing.
310 * However, the final result isn't necessarily available until the GPU processes
311 * those commands. brw_queryobj_get_results() processes the captured data to
312 * produce the final result.
315 brw_end_query(struct gl_context *ctx, struct gl_query_object *q)
317 struct brw_context *brw = brw_context(ctx);
318 struct intel_context *intel = intel_context(ctx);
319 struct brw_query_object *query = (struct brw_query_object *)q;
321 assert(intel->gen < 6);
323 switch (query->Base.Target) {
324 case GL_TIME_ELAPSED_EXT:
325 /* Write the final timestamp. */
326 write_timestamp(intel, query->bo, 1);
329 case GL_ANY_SAMPLES_PASSED:
330 case GL_ANY_SAMPLES_PASSED_CONSERVATIVE:
331 case GL_SAMPLES_PASSED_ARB:
333 /* No query->bo means that EndQuery was called after BeginQuery with no
334 * intervening drawing. Rather than doing nothing at all here in this
335 * case, we emit the query_begin and query_end state to the
336 * hardware. This is to guarantee that waiting on the result of this
337 * empty state will cause all previous queries to complete at all, as
338 * required by the specification:
340 * It must always be true that if any query object
341 * returns a result available of TRUE, all queries of the
342 * same type issued prior to that query must also return
343 * TRUE. [Open GL 4.3 (Core Profile) Section 4.2.1]
346 brw_emit_query_begin(brw);
351 brw_emit_query_end(brw);
353 brw->query.obj = NULL;
356 brw->state.dirty.brw |= BRW_NEW_STATS_WM;
360 assert(!"Unrecognized query target in brw_end_query()");
366 * The Gen4-5 WaitQuery() driver hook.
368 * Wait for a query result to become available and return it. This is the
369 * backing for glGetQueryObjectiv() with the GL_QUERY_RESULT pname.
371 static void brw_wait_query(struct gl_context *ctx, struct gl_query_object *q)
373 struct brw_query_object *query = (struct brw_query_object *)q;
375 assert(intel_context(ctx)->gen < 6);
377 brw_queryobj_get_results(ctx, query);
378 query->Base.Ready = true;
382 * The Gen4-5 CheckQuery() driver hook.
384 * Checks whether a query result is ready yet. If not, flushes.
385 * This is the backing for glGetQueryObjectiv()'s QUERY_RESULT_AVAILABLE pname.
387 static void brw_check_query(struct gl_context *ctx, struct gl_query_object *q)
389 struct intel_context *intel = intel_context(ctx);
390 struct brw_query_object *query = (struct brw_query_object *)q;
392 assert(intel->gen < 6);
394 /* From the GL_ARB_occlusion_query spec:
396 * "Instead of allowing for an infinite loop, performing a
397 * QUERY_RESULT_AVAILABLE_ARB will perform a flush if the result is
398 * not ready yet on the first time it is queried. This ensures that
399 * the async query will return true in finite time.
401 if (query->bo && drm_intel_bo_references(intel->batch.bo, query->bo))
402 intel_batchbuffer_flush(intel);
404 if (query->bo == NULL || !drm_intel_bo_busy(query->bo)) {
405 brw_queryobj_get_results(ctx, query);
406 query->Base.Ready = true;
411 * Ensure there query's BO has enough space to store a new pair of values.
413 * If not, gather the existing BO's results and create a new buffer of the
417 ensure_bo_has_space(struct gl_context *ctx, struct brw_query_object *query)
419 struct intel_context *intel = intel_context(ctx);
421 assert(intel->gen < 6);
423 if (!query->bo || query->last_index * 2 + 1 >= 4096 / sizeof(uint64_t)) {
425 if (query->bo != NULL) {
426 /* The old query BO did not have enough space, so we allocated a new
427 * one. Gather the results so far (adding up the differences) and
428 * release the old BO.
430 brw_queryobj_get_results(ctx, query);
433 query->bo = drm_intel_bo_alloc(intel->bufmgr, "query", 4096, 1);
434 query->last_index = 0;
439 * Record the PS_DEPTH_COUNT value (for occlusion queries) just before
442 * In a pre-hardware context world, the single PS_DEPTH_COUNT register is
443 * shared among all applications using the GPU. However, our query value
444 * needs to only include fragments generated by our application/GL context.
446 * To accommodate this, we record PS_DEPTH_COUNT at the start and end of
447 * each batchbuffer (technically, the first primitive drawn and flush time).
448 * Subtracting each pair of values calculates the change in PS_DEPTH_COUNT
449 * caused by a batchbuffer. Since there is no preemption inside batches,
450 * this is guaranteed to only measure the effects of our current application.
452 * Adding each of these differences (in case drawing is done over many batches)
453 * produces the final expected value.
455 * In a world with hardware contexts, PS_DEPTH_COUNT is saved and restored
456 * as part of the context state, so this is unnecessary, and skipped.
459 brw_emit_query_begin(struct brw_context *brw)
461 struct intel_context *intel = &brw->intel;
462 struct gl_context *ctx = &intel->ctx;
463 struct brw_query_object *query = brw->query.obj;
468 /* Skip if we're not doing any queries, or we've already recorded the
469 * initial query value for this batchbuffer.
471 if (!query || brw->query.begin_emitted)
474 ensure_bo_has_space(ctx, query);
476 write_depth_count(intel, query->bo, query->last_index * 2);
478 brw->query.begin_emitted = true;
482 * Called at batchbuffer flush to get an ending PS_DEPTH_COUNT
483 * (for non-hardware context platforms).
485 * See the explanation in brw_emit_query_begin().
488 brw_emit_query_end(struct brw_context *brw)
490 struct intel_context *intel = &brw->intel;
491 struct brw_query_object *query = brw->query.obj;
496 if (!brw->query.begin_emitted)
499 write_depth_count(intel, query->bo, query->last_index * 2 + 1);
501 brw->query.begin_emitted = false;
506 * Driver hook for glQueryCounter().
508 * This handles GL_TIMESTAMP queries, which perform a pipelined read of the
509 * current GPU time. This is unlike GL_TIME_ELAPSED, which measures the
510 * time while the query is active.
513 brw_query_counter(struct gl_context *ctx, struct gl_query_object *q)
515 struct intel_context *intel = intel_context(ctx);
516 struct brw_query_object *query = (struct brw_query_object *) q;
518 assert(q->Target == GL_TIMESTAMP);
520 drm_intel_bo_unreference(query->bo);
521 query->bo = drm_intel_bo_alloc(intel->bufmgr, "timestamp query", 4096, 4096);
522 write_timestamp(intel, query->bo, 0);
526 * Read the TIMESTAMP register immediately (in a non-pipelined fashion).
528 * This is used to implement the GetTimestamp() driver hook.
531 brw_get_timestamp(struct gl_context *ctx)
533 struct intel_context *intel = intel_context(ctx);
536 drm_intel_reg_read(intel->bufmgr, TIMESTAMP, &result);
538 /* See logic in brw_queryobj_get_results() */
539 result = result >> 32;
541 result &= (1ull << 36) - 1;
546 /* Initialize query object functions used on all generations. */
547 void brw_init_common_queryobj_functions(struct dd_function_table *functions)
549 functions->NewQueryObject = brw_new_query_object;
550 functions->DeleteQuery = brw_delete_query;
551 functions->QueryCounter = brw_query_counter;
552 functions->GetTimestamp = brw_get_timestamp;
555 /* Initialize Gen4/5-specific query object functions. */
556 void gen4_init_queryobj_functions(struct dd_function_table *functions)
558 functions->BeginQuery = brw_begin_query;
559 functions->EndQuery = brw_end_query;
560 functions->CheckQuery = brw_check_query;
561 functions->WaitQuery = brw_wait_query;