src/mesa/drivers/dri/i965/brw_queryobj.c

   1 /*
   2  * Copyright © 2008 Intel Corporation
   3  *
   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:
  10  *
  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
  13  * Software.
  14  *
  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
  21  * IN THE SOFTWARE.
  22  *
  23  * Authors:
  24  *    Eric Anholt <eric@anholt.net>
  25  *
  26  */
  27
  28 /** @file brw_queryobj.c
  29  *
  30  * Support for query objects (GL_ARB_occlusion_query, GL_ARB_timer_query,
  31  * GL_EXT_transform_feedback, and friends).
  32  *
  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'
  36  * needs.
  37  *
  38  * To avoid getting samples from another context's rendering in our results,
  39  * we capture the counts at the start and end of every batchbuffer while the
  40  * query is active, and sum up the differences.  (We should do so for
  41  * GL_TIME_ELAPSED as well, but don't).
  42  */
  43 #include "main/imports.h"
  44
  45 #include "brw_context.h"
  46 #include "brw_defines.h"
  47 #include "brw_state.h"
  48 #include "intel_batchbuffer.h"
  49 #include "intel_reg.h"
  50
  51 static void
  52 write_timestamp(struct intel_context *intel, drm_intel_bo *query_bo, int idx)
  53 {
  54    if (intel->gen >= 6) {
  55       /* Emit workaround flushes: */
  56       if (intel->gen == 6) {
  57          /* The timestamp write below is a non-zero post-sync op, which on
  58           * Gen6 necessitates a CS stall.  CS stalls need stall at scoreboard
  59           * set.  See the comments for intel_emit_post_sync_nonzero_flush().
  60           */
  61          BEGIN_BATCH(4);
  62          OUT_BATCH(_3DSTATE_PIPE_CONTROL | (4 - 2));
  63          OUT_BATCH(PIPE_CONTROL_CS_STALL | PIPE_CONTROL_STALL_AT_SCOREBOARD);
  64          OUT_BATCH(0);
  65          OUT_BATCH(0);
  66          ADVANCE_BATCH();
  67       }
  68
  69       BEGIN_BATCH(5);
  70       OUT_BATCH(_3DSTATE_PIPE_CONTROL | (5 - 2));
  71       OUT_BATCH(PIPE_CONTROL_WRITE_TIMESTAMP);
  72       OUT_RELOC(query_bo,
  73                 I915_GEM_DOMAIN_INSTRUCTION, I915_GEM_DOMAIN_INSTRUCTION,
  74                 PIPE_CONTROL_GLOBAL_GTT_WRITE |
  75                 idx * sizeof(uint64_t));
  76       OUT_BATCH(0);
  77       OUT_BATCH(0);
  78       ADVANCE_BATCH();
  79    } else {
  80       BEGIN_BATCH(4);
  81       OUT_BATCH(_3DSTATE_PIPE_CONTROL | (4 - 2) |
  82                 PIPE_CONTROL_WRITE_TIMESTAMP);
  83       OUT_RELOC(query_bo,
  84                 I915_GEM_DOMAIN_INSTRUCTION, I915_GEM_DOMAIN_INSTRUCTION,
  85                 PIPE_CONTROL_GLOBAL_GTT_WRITE |
  86                 idx * sizeof(uint64_t));
  87       OUT_BATCH(0);
  88       OUT_BATCH(0);
  89       ADVANCE_BATCH();
  90    }
  91 }
  92
  93 static void
  94 write_depth_count(struct intel_context *intel, drm_intel_bo *query_bo, int idx)
  95 {
  96    if (intel->gen >= 6) {
  97       /* Emit Sandybridge workaround flush: */
  98       if (intel->gen == 6)
  99          intel_emit_post_sync_nonzero_flush(intel);
 100
 101       BEGIN_BATCH(5);
 102       OUT_BATCH(_3DSTATE_PIPE_CONTROL | (5 - 2));
 103       OUT_BATCH(PIPE_CONTROL_DEPTH_STALL |
 104                 PIPE_CONTROL_WRITE_DEPTH_COUNT);
 105       OUT_RELOC(query_bo,
 106                 I915_GEM_DOMAIN_INSTRUCTION, I915_GEM_DOMAIN_INSTRUCTION,
 107                 PIPE_CONTROL_GLOBAL_GTT_WRITE |
 108                 (idx * sizeof(uint64_t)));
 109       OUT_BATCH(0);
 110       OUT_BATCH(0);
 111       ADVANCE_BATCH();
 112    } else {
 113       BEGIN_BATCH(4);
 114       OUT_BATCH(_3DSTATE_PIPE_CONTROL | (4 - 2) |
 115                 PIPE_CONTROL_DEPTH_STALL |
 116                 PIPE_CONTROL_WRITE_DEPTH_COUNT);
 117       /* This object could be mapped cacheable, but we don't have an exposed
 118        * mechanism to support that.  Since it's going uncached, tell GEM that
 119        * we're writing to it.  The usual clflush should be all that's required
 120        * to pick up the results.
 121        */
 122       OUT_RELOC(query_bo,
 123                 I915_GEM_DOMAIN_INSTRUCTION, I915_GEM_DOMAIN_INSTRUCTION,
 124                 PIPE_CONTROL_GLOBAL_GTT_WRITE |
 125                 (idx * sizeof(uint64_t)));
 126       OUT_BATCH(0);
 127       OUT_BATCH(0);
 128       ADVANCE_BATCH();
 129    }
 130 }
 131
 132 /** Waits on the query object's BO and totals the results for this query */
 133 static void
 134 brw_queryobj_get_results(struct gl_context *ctx,
 135                          struct brw_query_object *query)
 136 {
 137    struct intel_context *intel = intel_context(ctx);
 138
 139    int i;
 140    uint64_t *results;
 141
 142    if (query->bo == NULL)
 143       return;
 144
 145    if (drm_intel_bo_references(intel->batch.bo, query->bo))
 146       intel_batchbuffer_flush(intel);
 147
 148    if (unlikely(INTEL_DEBUG & DEBUG_PERF)) {
 149       if (drm_intel_bo_busy(query->bo)) {
 150          perf_debug("Stalling on the GPU waiting for a query object.\n");
 151       }
 152    }
 153
 154    drm_intel_bo_map(query->bo, false);
 155    results = query->bo->virtual;
 156    switch (query->Base.Target) {
 157    case GL_TIME_ELAPSED_EXT:
 158       if (intel->gen >= 6)
 159          query->Base.Result += 80 * (results[1] - results[0]);
 160       else
 161          query->Base.Result += 1000 * ((results[1] >> 32) - (results[0] >> 32));
 162       break;
 163
 164    case GL_TIMESTAMP:
 165       if (intel->gen >= 6) {
 166          /* Our timer is a clock that increments every 80ns (regardless of
 167           * other clock scaling in the system).  The timestamp register we can
 168           * read for glGetTimestamp() masks out the top 32 bits, so we do that
 169           * here too to let the two counters be compared against each other.
 170           *
 171           * If we just multiplied that 32 bits of data by 80, it would roll
 172           * over at a non-power-of-two, so an application couldn't use
 173           * GL_QUERY_COUNTER_BITS to handle rollover correctly.  Instead, we
 174           * report 36 bits and truncate at that (rolling over 5 times as often
 175           * as the HW counter), and when the 32-bit counter rolls over, it
 176           * happens to also be at a rollover in the reported value from near
 177           * (1<<36) to 0.
 178           *
 179           * The low 32 bits rolls over in ~343 seconds.  Our 36-bit result
 180           * rolls over every ~69 seconds.
 181           */
 182          query->Base.Result = 80 * (results[1] & 0xffffffff);
 183          query->Base.Result &= (1ull << 36) - 1;
 184       } else {
 185          query->Base.Result = 1000 * (results[1] >> 32);
 186       }
 187
 188       break;
 189
 190    case GL_SAMPLES_PASSED_ARB:
 191       /* Map and count the pixels from the current query BO */
 192       for (i = query->first_index; i <= query->last_index; i++) {
 193          query->Base.Result += results[i * 2 + 1] - results[i * 2];
 194       }
 195       break;
 196
 197    case GL_PRIMITIVES_GENERATED:
 198    case GL_TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN:
 199       /* We don't actually query the hardware for this value, so query->bo
 200        * should always be NULL and execution should never reach here.
 201        */
 202       assert(!"Unreachable");
 203       break;
 204
 205    default:
 206       assert(!"Unrecognized query target in brw_queryobj_get_results()");
 207       break;
 208    }
 209    drm_intel_bo_unmap(query->bo);
 210
 211    drm_intel_bo_unreference(query->bo);
 212    query->bo = NULL;
 213 }
 214
 215 static struct gl_query_object *
 216 brw_new_query_object(struct gl_context *ctx, GLuint id)
 217 {
 218    struct brw_query_object *query;
 219
 220    query = calloc(1, sizeof(struct brw_query_object));
 221
 222    query->Base.Id = id;
 223    query->Base.Result = 0;
 224    query->Base.Active = false;
 225    query->Base.Ready = true;
 226
 227    return &query->Base;
 228 }
 229
 230 static void
 231 brw_delete_query(struct gl_context *ctx, struct gl_query_object *q)
 232 {
 233    struct brw_query_object *query = (struct brw_query_object *)q;
 234
 235    drm_intel_bo_unreference(query->bo);
 236    free(query);
 237 }
 238
 239 static void
 240 brw_begin_query(struct gl_context *ctx, struct gl_query_object *q)
 241 {
 242    struct brw_context *brw = brw_context(ctx);
 243    struct intel_context *intel = intel_context(ctx);
 244    struct brw_query_object *query = (struct brw_query_object *)q;
 245
 246    switch (query->Base.Target) {
 247    case GL_TIME_ELAPSED_EXT:
 248       drm_intel_bo_unreference(query->bo);
 249       query->bo = drm_intel_bo_alloc(intel->bufmgr, "timer query", 4096, 4096);
 250       write_timestamp(intel, query->bo, 0);
 251       break;
 252
 253    case GL_SAMPLES_PASSED_ARB:
 254       /* Reset our driver's tracking of query state. */
 255       drm_intel_bo_unreference(query->bo);
 256       query->bo = NULL;
 257       query->first_index = -1;
 258       query->last_index = -1;
 259
 260       brw->query.obj = query;
 261       intel->stats_wm++;
 262       break;
 263
 264    case GL_PRIMITIVES_GENERATED:
 265       /* We don't actually query the hardware for this value; we keep track of
 266        * it a software counter.  So just reset the counter.
 267        */
 268       brw->sol.primitives_generated = 0;
 269       brw->sol.counting_primitives_generated = true;
 270       break;
 271
 272    case GL_TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN:
 273       /* We don't actually query the hardware for this value; we keep track of
 274        * it a software counter.  So just reset the counter.
 275        */
 276       brw->sol.primitives_written = 0;
 277       brw->sol.counting_primitives_written = true;
 278       break;
 279
 280    default:
 281       assert(!"Unrecognized query target in brw_begin_query()");
 282       break;
 283    }
 284 }
 285
 286 /**
 287  * Begin the ARB_occlusion_query query on a query object.
 288  */
 289 static void
 290 brw_end_query(struct gl_context *ctx, struct gl_query_object *q)
 291 {
 292    struct brw_context *brw = brw_context(ctx);
 293    struct intel_context *intel = intel_context(ctx);
 294    struct brw_query_object *query = (struct brw_query_object *)q;
 295
 296    switch (query->Base.Target) {
 297    case GL_TIMESTAMP:
 298       drm_intel_bo_unreference(query->bo);
 299       query->bo = drm_intel_bo_alloc(intel->bufmgr, "timer query",
 300                                      4096, 4096);
 301       /* FALLTHROUGH */
 302
 303    case GL_TIME_ELAPSED_EXT:
 304       write_timestamp(intel, query->bo, 1);
 305       intel_batchbuffer_flush(intel);
 306       break;
 307
 308    case GL_SAMPLES_PASSED_ARB:
 309       if (query->bo) {
 310          brw_emit_query_end(brw);
 311
 312          drm_intel_bo_unreference(brw->query.bo);
 313          brw->query.bo = NULL;
 314       }
 315
 316       brw->query.obj = NULL;
 317
 318       intel->stats_wm--;
 319       break;
 320
 321    case GL_PRIMITIVES_GENERATED:
 322       /* We don't actually query the hardware for this value; we keep track of
 323        * it in a software counter.  So just read the counter and store it in
 324        * the query object.
 325        */
 326       query->Base.Result = brw->sol.primitives_generated;
 327       brw->sol.counting_primitives_generated = false;
 328
 329       /* And set brw->query.obj to NULL so that this query won't try to wait
 330        * for any rendering to complete.
 331        */
 332       query->bo = NULL;
 333       break;
 334
 335    case GL_TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN:
 336       /* We don't actually query the hardware for this value; we keep track of
 337        * it in a software counter.  So just read the counter and store it in
 338        * the query object.
 339        */
 340       query->Base.Result = brw->sol.primitives_written;
 341       brw->sol.counting_primitives_written = false;
 342
 343       /* And set brw->query.obj to NULL so that this query won't try to wait
 344        * for any rendering to complete.
 345        */
 346       query->bo = NULL;
 347       break;
 348
 349    default:
 350       assert(!"Unrecognized query target in brw_end_query()");
 351       break;
 352    }
 353 }
 354
 355 static void brw_wait_query(struct gl_context *ctx, struct gl_query_object *q)
 356 {
 357    struct brw_query_object *query = (struct brw_query_object *)q;
 358
 359    brw_queryobj_get_results(ctx, query);
 360    query->Base.Ready = true;
 361 }
 362
 363 static void brw_check_query(struct gl_context *ctx, struct gl_query_object *q)
 364 {
 365    struct intel_context *intel = intel_context(ctx);
 366    struct brw_query_object *query = (struct brw_query_object *)q;
 367
 368    /* From the GL_ARB_occlusion_query spec:
 369     *
 370     *     "Instead of allowing for an infinite loop, performing a
 371     *      QUERY_RESULT_AVAILABLE_ARB will perform a flush if the result is
 372     *      not ready yet on the first time it is queried.  This ensures that
 373     *      the async query will return true in finite time.
 374     */
 375    if (query->bo && drm_intel_bo_references(intel->batch.bo, query->bo))
 376       intel_batchbuffer_flush(intel);
 377
 378    if (query->bo == NULL || !drm_intel_bo_busy(query->bo)) {
 379       brw_queryobj_get_results(ctx, query);
 380       query->Base.Ready = true;
 381    }
 382 }
 383
 384 /** Called to set up the query BO and account for its aperture space */
 385 void
 386 brw_prepare_query_begin(struct brw_context *brw)
 387 {
 388    struct intel_context *intel = &brw->intel;
 389
 390    /* Skip if we're not doing any queries. */
 391    if (!brw->query.obj)
 392       return;
 393
 394    /* Get a new query BO if we're going to need it. */
 395    if (brw->query.bo == NULL ||
 396        brw->query.index * 2 + 1 >= 4096 / sizeof(uint64_t)) {
 397       drm_intel_bo_unreference(brw->query.bo);
 398       brw->query.bo = NULL;
 399
 400       brw->query.bo = drm_intel_bo_alloc(intel->bufmgr, "query", 4096, 1);
 401
 402       /* clear target buffer */
 403       drm_intel_bo_map(brw->query.bo, true);
 404       memset((char *)brw->query.bo->virtual, 0, 4096);
 405       drm_intel_bo_unmap(brw->query.bo);
 406
 407       brw->query.index = 0;
 408    }
 409 }
 410
 411 /** Called just before primitive drawing to get a beginning PS_DEPTH_COUNT. */
 412 void
 413 brw_emit_query_begin(struct brw_context *brw)
 414 {
 415    struct intel_context *intel = &brw->intel;
 416    struct gl_context *ctx = &intel->ctx;
 417    struct brw_query_object *query = brw->query.obj;
 418
 419    /* Skip if we're not doing any queries, or we've emitted the start. */
 420    if (!query || brw->query.active)
 421       return;
 422
 423    write_depth_count(intel, brw->query.bo, brw->query.index * 2);
 424
 425    if (query->bo != brw->query.bo) {
 426       if (query->bo != NULL)
 427          brw_queryobj_get_results(ctx, query);
 428       drm_intel_bo_reference(brw->query.bo);
 429       query->bo = brw->query.bo;
 430       query->first_index = brw->query.index;
 431    }
 432    query->last_index = brw->query.index;
 433    brw->query.active = true;
 434 }
 435
 436 /** Called at batchbuffer flush to get an ending PS_DEPTH_COUNT */
 437 void
 438 brw_emit_query_end(struct brw_context *brw)
 439 {
 440    struct intel_context *intel = &brw->intel;
 441
 442    if (!brw->query.active)
 443       return;
 444
 445    write_depth_count(intel, brw->query.bo, brw->query.index * 2 + 1);
 446
 447    brw->query.active = false;
 448    brw->query.index++;
 449 }
 450
 451 static uint64_t
 452 brw_get_timestamp(struct gl_context *ctx)
 453 {
 454    struct intel_context *intel = intel_context(ctx);
 455    uint64_t result = 0;
 456
 457    drm_intel_reg_read(intel->bufmgr, TIMESTAMP, &result);
 458
 459    /* See logic in brw_queryobj_get_results() */
 460    result = result >> 32;
 461    result *= 80;
 462    result &= (1ull << 36) - 1;
 463
 464    return result;
 465 }
 466
 467 void brw_init_queryobj_functions(struct dd_function_table *functions)
 468 {
 469    functions->NewQueryObject = brw_new_query_object;
 470    functions->DeleteQuery = brw_delete_query;
 471    functions->BeginQuery = brw_begin_query;
 472    functions->EndQuery = brw_end_query;
 473    functions->CheckQuery = brw_check_query;
 474    functions->WaitQuery = brw_wait_query;
 475    functions->GetTimestamp = brw_get_timestamp;
 476 }