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"
46 brw_timebase_scale(struct brw_context
*brw
, uint64_t gpu_timestamp
)
48 const struct gen_device_info
*devinfo
= &brw
->screen
->devinfo
;
50 return (double)gpu_timestamp
* devinfo
->timebase_scale
;
53 /* As best we know currently, the Gen HW timestamps are 36bits across
54 * all platforms, which we need to account for when calculating a
55 * delta to measure elapsed time.
57 * The timestamps read via glGetTimestamp() / brw_get_timestamp() sometimes
58 * only have 32bits due to a kernel bug and so in that case we make sure to
59 * treat all raw timestamps as 32bits so they overflow consistently and remain
60 * comparable. (Note: the timestamps being passed here are not from the kernel
61 * so we don't need to be taking the upper 32bits in this buggy kernel case we
62 * are just clipping to 32bits here for consistency.)
65 brw_raw_timestamp_delta(struct brw_context
*brw
, uint64_t time0
, uint64_t time1
)
67 if (brw
->screen
->hw_has_timestamp
== 2) {
68 /* Kernel clips timestamps to 32bits in this case, so we also clip
69 * PIPE_CONTROL timestamps for consistency.
71 return (uint32_t)time1
- (uint32_t)time0
;
74 return (1ULL << 36) + time1
- time0
;
82 * Emit PIPE_CONTROLs to write the current GPU timestamp into a buffer.
85 brw_write_timestamp(struct brw_context
*brw
, struct brw_bo
*query_bo
, int idx
)
88 /* Emit Sandybridge workaround flush: */
89 brw_emit_pipe_control_flush(brw
,
90 PIPE_CONTROL_CS_STALL
|
91 PIPE_CONTROL_STALL_AT_SCOREBOARD
);
94 uint32_t flags
= PIPE_CONTROL_WRITE_TIMESTAMP
;
96 if (brw
->gen
== 9 && brw
->gt
== 4)
97 flags
|= PIPE_CONTROL_CS_STALL
;
99 brw_emit_pipe_control_write(brw
, flags
,
100 query_bo
, idx
* sizeof(uint64_t), 0, 0);
104 * Emit PIPE_CONTROLs to write the PS_DEPTH_COUNT register into a buffer.
107 brw_write_depth_count(struct brw_context
*brw
, struct brw_bo
*query_bo
, int idx
)
109 uint32_t flags
= PIPE_CONTROL_WRITE_DEPTH_COUNT
| PIPE_CONTROL_DEPTH_STALL
;
111 if (brw
->gen
== 9 && brw
->gt
== 4)
112 flags
|= PIPE_CONTROL_CS_STALL
;
114 brw_emit_pipe_control_write(brw
, flags
,
115 query_bo
, idx
* sizeof(uint64_t),
120 * Wait on the query object's BO and calculate the final result.
123 brw_queryobj_get_results(struct gl_context
*ctx
,
124 struct brw_query_object
*query
)
126 struct brw_context
*brw
= brw_context(ctx
);
131 assert(brw
->gen
< 6);
133 if (query
->bo
== NULL
)
136 /* If the application has requested the query result, but this batch is
137 * still contributing to it, flush it now so the results will be present
140 if (brw_batch_references(&brw
->batch
, query
->bo
))
141 intel_batchbuffer_flush(brw
);
143 if (unlikely(brw
->perf_debug
)) {
144 if (brw_bo_busy(query
->bo
)) {
145 perf_debug("Stalling on the GPU waiting for a query object.\n");
149 brw_bo_map(brw
, query
->bo
, false);
150 results
= query
->bo
->virtual;
151 switch (query
->Base
.Target
) {
152 case GL_TIME_ELAPSED_EXT
:
153 /* The query BO contains the starting and ending timestamps.
154 * Subtract the two and convert to nanoseconds.
156 query
->Base
.Result
= brw_raw_timestamp_delta(brw
, results
[0], results
[1]);
157 query
->Base
.Result
= brw_timebase_scale(brw
, query
->Base
.Result
);
161 /* The query BO contains a single timestamp value in results[0]. */
162 query
->Base
.Result
= brw_timebase_scale(brw
, results
[0]);
164 /* Ensure the scaled timestamp overflows according to
165 * GL_QUERY_COUNTER_BITS
167 query
->Base
.Result
&= (1ull << ctx
->Const
.QueryCounterBits
.Timestamp
) - 1;
170 case GL_SAMPLES_PASSED_ARB
:
171 /* Loop over pairs of values from the BO, which are the PS_DEPTH_COUNT
172 * value at the start and end of the batchbuffer. Subtract them to
173 * get the number of fragments which passed the depth test in each
174 * individual batch, and add those differences up to get the number
175 * of fragments for the entire query.
177 * Note that query->Base.Result may already be non-zero. We may have
178 * run out of space in the query's BO and allocated a new one. If so,
179 * this function was already called to accumulate the results so far.
181 for (i
= 0; i
< query
->last_index
; i
++) {
182 query
->Base
.Result
+= results
[i
* 2 + 1] - results
[i
* 2];
186 case GL_ANY_SAMPLES_PASSED
:
187 case GL_ANY_SAMPLES_PASSED_CONSERVATIVE
:
188 /* If the starting and ending PS_DEPTH_COUNT from any of the batches
189 * differ, then some fragments passed the depth test.
191 for (i
= 0; i
< query
->last_index
; i
++) {
192 if (results
[i
* 2 + 1] != results
[i
* 2]) {
193 query
->Base
.Result
= GL_TRUE
;
200 unreachable("Unrecognized query target in brw_queryobj_get_results()");
202 brw_bo_unmap(query
->bo
);
204 /* Now that we've processed the data stored in the query's buffer object,
207 brw_bo_unreference(query
->bo
);
212 * The NewQueryObject() driver hook.
214 * Allocates and initializes a new query object.
216 static struct gl_query_object
*
217 brw_new_query_object(struct gl_context
*ctx
, GLuint id
)
219 struct brw_query_object
*query
;
221 query
= calloc(1, sizeof(struct brw_query_object
));
224 query
->Base
.Result
= 0;
225 query
->Base
.Active
= false;
226 query
->Base
.Ready
= true;
232 * The DeleteQuery() driver hook.
235 brw_delete_query(struct gl_context
*ctx
, struct gl_query_object
*q
)
237 struct brw_query_object
*query
= (struct brw_query_object
*)q
;
239 brw_bo_unreference(query
->bo
);
244 * Gen4-5 driver hook for glBeginQuery().
246 * Initializes driver structures and emits any GPU commands required to begin
247 * recording data for the query.
250 brw_begin_query(struct gl_context
*ctx
, struct gl_query_object
*q
)
252 struct brw_context
*brw
= brw_context(ctx
);
253 struct brw_query_object
*query
= (struct brw_query_object
*)q
;
255 assert(brw
->gen
< 6);
257 switch (query
->Base
.Target
) {
258 case GL_TIME_ELAPSED_EXT
:
259 /* For timestamp queries, we record the starting time right away so that
260 * we measure the full time between BeginQuery and EndQuery. There's
261 * some debate about whether this is the right thing to do. Our decision
262 * is based on the following text from the ARB_timer_query extension:
264 * "(5) Should the extension measure total time elapsed between the full
265 * completion of the BeginQuery and EndQuery commands, or just time
266 * spent in the graphics library?
268 * RESOLVED: This extension will measure the total time elapsed
269 * between the full completion of these commands. Future extensions
270 * may implement a query to determine time elapsed at different stages
271 * of the graphics pipeline."
273 * We write a starting timestamp now (at index 0). At EndQuery() time,
274 * we'll write a second timestamp (at index 1), and subtract the two to
275 * obtain the time elapsed. Notably, this includes time elapsed while
276 * the system was doing other work, such as running other applications.
278 brw_bo_unreference(query
->bo
);
279 query
->bo
= brw_bo_alloc(brw
->bufmgr
, "timer query", 4096, 4096);
280 brw_write_timestamp(brw
, query
->bo
, 0);
283 case GL_ANY_SAMPLES_PASSED
:
284 case GL_ANY_SAMPLES_PASSED_CONSERVATIVE
:
285 case GL_SAMPLES_PASSED_ARB
:
286 /* For occlusion queries, we delay taking an initial sample until the
287 * first drawing occurs in this batch. See the reasoning in the comments
288 * for brw_emit_query_begin() below.
290 * Since we're starting a new query, we need to be sure to throw away
291 * any previous occlusion query results.
293 brw_bo_unreference(query
->bo
);
295 query
->last_index
= -1;
297 brw
->query
.obj
= query
;
299 /* Depth statistics on Gen4 require strange workarounds, so we try to
300 * avoid them when necessary. They're required for occlusion queries,
301 * so turn them on now.
304 brw
->ctx
.NewDriverState
|= BRW_NEW_STATS_WM
;
308 unreachable("Unrecognized query target in brw_begin_query()");
313 * Gen4-5 driver hook for glEndQuery().
315 * Emits GPU commands to record a final query value, ending any data capturing.
316 * However, the final result isn't necessarily available until the GPU processes
317 * those commands. brw_queryobj_get_results() processes the captured data to
318 * produce the final result.
321 brw_end_query(struct gl_context
*ctx
, struct gl_query_object
*q
)
323 struct brw_context
*brw
= brw_context(ctx
);
324 struct brw_query_object
*query
= (struct brw_query_object
*)q
;
326 assert(brw
->gen
< 6);
328 switch (query
->Base
.Target
) {
329 case GL_TIME_ELAPSED_EXT
:
330 /* Write the final timestamp. */
331 brw_write_timestamp(brw
, query
->bo
, 1);
334 case GL_ANY_SAMPLES_PASSED
:
335 case GL_ANY_SAMPLES_PASSED_CONSERVATIVE
:
336 case GL_SAMPLES_PASSED_ARB
:
338 /* No query->bo means that EndQuery was called after BeginQuery with no
339 * intervening drawing. Rather than doing nothing at all here in this
340 * case, we emit the query_begin and query_end state to the
341 * hardware. This is to guarantee that waiting on the result of this
342 * empty state will cause all previous queries to complete at all, as
343 * required by the specification:
345 * It must always be true that if any query object
346 * returns a result available of TRUE, all queries of the
347 * same type issued prior to that query must also return
348 * TRUE. [Open GL 4.3 (Core Profile) Section 4.2.1]
351 brw_emit_query_begin(brw
);
356 brw_emit_query_end(brw
);
358 brw
->query
.obj
= NULL
;
361 brw
->ctx
.NewDriverState
|= BRW_NEW_STATS_WM
;
365 unreachable("Unrecognized query target in brw_end_query()");
370 * The Gen4-5 WaitQuery() driver hook.
372 * Wait for a query result to become available and return it. This is the
373 * backing for glGetQueryObjectiv() with the GL_QUERY_RESULT pname.
375 static void brw_wait_query(struct gl_context
*ctx
, struct gl_query_object
*q
)
377 struct brw_query_object
*query
= (struct brw_query_object
*)q
;
379 assert(brw_context(ctx
)->gen
< 6);
381 brw_queryobj_get_results(ctx
, query
);
382 query
->Base
.Ready
= true;
386 * The Gen4-5 CheckQuery() driver hook.
388 * Checks whether a query result is ready yet. If not, flushes.
389 * This is the backing for glGetQueryObjectiv()'s QUERY_RESULT_AVAILABLE pname.
391 static void brw_check_query(struct gl_context
*ctx
, struct gl_query_object
*q
)
393 struct brw_context
*brw
= brw_context(ctx
);
394 struct brw_query_object
*query
= (struct brw_query_object
*)q
;
396 assert(brw
->gen
< 6);
398 /* From the GL_ARB_occlusion_query spec:
400 * "Instead of allowing for an infinite loop, performing a
401 * QUERY_RESULT_AVAILABLE_ARB will perform a flush if the result is
402 * not ready yet on the first time it is queried. This ensures that
403 * the async query will return true in finite time.
405 if (query
->bo
&& brw_batch_references(&brw
->batch
, query
->bo
))
406 intel_batchbuffer_flush(brw
);
408 if (query
->bo
== NULL
|| !brw_bo_busy(query
->bo
)) {
409 brw_queryobj_get_results(ctx
, query
);
410 query
->Base
.Ready
= true;
415 * Ensure there query's BO has enough space to store a new pair of values.
417 * If not, gather the existing BO's results and create a new buffer of the
421 ensure_bo_has_space(struct gl_context
*ctx
, struct brw_query_object
*query
)
423 struct brw_context
*brw
= brw_context(ctx
);
425 assert(brw
->gen
< 6);
427 if (!query
->bo
|| query
->last_index
* 2 + 1 >= 4096 / sizeof(uint64_t)) {
429 if (query
->bo
!= NULL
) {
430 /* The old query BO did not have enough space, so we allocated a new
431 * one. Gather the results so far (adding up the differences) and
432 * release the old BO.
434 brw_queryobj_get_results(ctx
, query
);
437 query
->bo
= brw_bo_alloc(brw
->bufmgr
, "query", 4096, 1);
438 query
->last_index
= 0;
443 * Record the PS_DEPTH_COUNT value (for occlusion queries) just before
446 * In a pre-hardware context world, the single PS_DEPTH_COUNT register is
447 * shared among all applications using the GPU. However, our query value
448 * needs to only include fragments generated by our application/GL context.
450 * To accommodate this, we record PS_DEPTH_COUNT at the start and end of
451 * each batchbuffer (technically, the first primitive drawn and flush time).
452 * Subtracting each pair of values calculates the change in PS_DEPTH_COUNT
453 * caused by a batchbuffer. Since there is no preemption inside batches,
454 * this is guaranteed to only measure the effects of our current application.
456 * Adding each of these differences (in case drawing is done over many batches)
457 * produces the final expected value.
459 * In a world with hardware contexts, PS_DEPTH_COUNT is saved and restored
460 * as part of the context state, so this is unnecessary, and skipped.
463 brw_emit_query_begin(struct brw_context
*brw
)
465 struct gl_context
*ctx
= &brw
->ctx
;
466 struct brw_query_object
*query
= brw
->query
.obj
;
471 /* Skip if we're not doing any queries, or we've already recorded the
472 * initial query value for this batchbuffer.
474 if (!query
|| brw
->query
.begin_emitted
)
477 ensure_bo_has_space(ctx
, query
);
479 brw_write_depth_count(brw
, query
->bo
, query
->last_index
* 2);
481 brw
->query
.begin_emitted
= true;
485 * Called at batchbuffer flush to get an ending PS_DEPTH_COUNT
486 * (for non-hardware context platforms).
488 * See the explanation in brw_emit_query_begin().
491 brw_emit_query_end(struct brw_context
*brw
)
493 struct brw_query_object
*query
= brw
->query
.obj
;
498 if (!brw
->query
.begin_emitted
)
501 brw_write_depth_count(brw
, query
->bo
, query
->last_index
* 2 + 1);
503 brw
->query
.begin_emitted
= false;
508 * Driver hook for glQueryCounter().
510 * This handles GL_TIMESTAMP queries, which perform a pipelined read of the
511 * current GPU time. This is unlike GL_TIME_ELAPSED, which measures the
512 * time while the query is active.
515 brw_query_counter(struct gl_context
*ctx
, struct gl_query_object
*q
)
517 struct brw_context
*brw
= brw_context(ctx
);
518 struct brw_query_object
*query
= (struct brw_query_object
*) q
;
520 assert(q
->Target
== GL_TIMESTAMP
);
522 brw_bo_unreference(query
->bo
);
523 query
->bo
= brw_bo_alloc(brw
->bufmgr
, "timestamp query", 4096, 4096);
524 brw_write_timestamp(brw
, query
->bo
, 0);
526 query
->flushed
= false;
530 * Read the TIMESTAMP register immediately (in a non-pipelined fashion).
532 * This is used to implement the GetTimestamp() driver hook.
535 brw_get_timestamp(struct gl_context
*ctx
)
537 struct brw_context
*brw
= brw_context(ctx
);
540 switch (brw
->screen
->hw_has_timestamp
) {
541 case 3: /* New kernel, always full 36bit accuracy */
542 brw_reg_read(brw
->bufmgr
, TIMESTAMP
| 1, &result
);
544 case 2: /* 64bit kernel, result is left-shifted by 32bits, losing 4bits */
545 brw_reg_read(brw
->bufmgr
, TIMESTAMP
, &result
);
546 result
= result
>> 32;
548 case 1: /* 32bit kernel, result is 36bit wide but may be inaccurate! */
549 brw_reg_read(brw
->bufmgr
, TIMESTAMP
, &result
);
553 /* Scale to nanosecond units */
554 result
= brw_timebase_scale(brw
, result
);
556 /* Ensure the scaled timestamp overflows according to
557 * GL_QUERY_COUNTER_BITS. Technically this isn't required if
558 * querying GL_TIMESTAMP via glGetInteger but it seems best to keep
559 * QueryObject and GetInteger timestamps consistent.
561 result
&= (1ull << ctx
->Const
.QueryCounterBits
.Timestamp
) - 1;
566 * Is this type of query written by PIPE_CONTROL?
569 brw_is_query_pipelined(struct brw_query_object
*query
)
571 switch (query
->Base
.Target
) {
573 case GL_TIME_ELAPSED
:
574 case GL_ANY_SAMPLES_PASSED
:
575 case GL_ANY_SAMPLES_PASSED_CONSERVATIVE
:
576 case GL_SAMPLES_PASSED_ARB
:
579 case GL_PRIMITIVES_GENERATED
:
580 case GL_TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN
:
581 case GL_TRANSFORM_FEEDBACK_STREAM_OVERFLOW_ARB
:
582 case GL_TRANSFORM_FEEDBACK_OVERFLOW_ARB
:
583 case GL_VERTICES_SUBMITTED_ARB
:
584 case GL_PRIMITIVES_SUBMITTED_ARB
:
585 case GL_VERTEX_SHADER_INVOCATIONS_ARB
:
586 case GL_GEOMETRY_SHADER_INVOCATIONS
:
587 case GL_GEOMETRY_SHADER_PRIMITIVES_EMITTED_ARB
:
588 case GL_FRAGMENT_SHADER_INVOCATIONS_ARB
:
589 case GL_CLIPPING_INPUT_PRIMITIVES_ARB
:
590 case GL_CLIPPING_OUTPUT_PRIMITIVES_ARB
:
591 case GL_COMPUTE_SHADER_INVOCATIONS_ARB
:
592 case GL_TESS_CONTROL_SHADER_PATCHES_ARB
:
593 case GL_TESS_EVALUATION_SHADER_INVOCATIONS_ARB
:
597 unreachable("Unrecognized query target in is_query_pipelined()");
601 /* Initialize query object functions used on all generations. */
602 void brw_init_common_queryobj_functions(struct dd_function_table
*functions
)
604 functions
->NewQueryObject
= brw_new_query_object
;
605 functions
->DeleteQuery
= brw_delete_query
;
606 functions
->GetTimestamp
= brw_get_timestamp
;
609 /* Initialize Gen4/5-specific query object functions. */
610 void gen4_init_queryobj_functions(struct dd_function_table
*functions
)
612 functions
->BeginQuery
= brw_begin_query
;
613 functions
->EndQuery
= brw_end_query
;
614 functions
->CheckQuery
= brw_check_query
;
615 functions
->WaitQuery
= brw_wait_query
;
616 functions
->QueryCounter
= brw_query_counter
;