src/mesa/drivers/dri/i965/gen6_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  *    Kenneth Graunke <kenneth@whitecape.org>
  26  */
  27
  28 /** @file gen6_queryobj.c
  29  *
  30  * Support for query objects (GL_ARB_occlusion_query, GL_ARB_timer_query,
  31  * GL_EXT_transform_feedback, and friends) on platforms that support
  32  * hardware contexts (Gen6+).
  33  */
  34 #include "main/imports.h"
  35
  36 #include "brw_context.h"
  37 #include "brw_defines.h"
  38 #include "brw_state.h"
  39 #include "intel_batchbuffer.h"
  40 #include "intel_buffer_objects.h"
  41
  42 static inline void
  43 set_query_availability(struct brw_context *brw, struct brw_query_object *query,
  44                        bool available)
  45 {
  46    /* For platforms that support ARB_query_buffer_object, we write the
  47     * query availability for "pipelined" queries.
  48     *
  49     * Most counter snapshots are written by the command streamer, by
  50     * doing a CS stall and then MI_STORE_REGISTER_MEM.  For these
  51     * counters, the CS stall guarantees that the results will be
  52     * available when subsequent CS commands run.  So we don't need to
  53     * do any additional tracking.
  54     *
  55     * Other counters (occlusion queries and timestamp) are written by
  56     * PIPE_CONTROL, without a CS stall.  This means that we can't be
  57     * sure whether the writes have landed yet or not.  Performing a
  58     * PIPE_CONTROL with an immediate write will synchronize with
  59     * those earlier writes, so we write 1 when the value has landed.
  60     */
  61    if (brw->ctx.Extensions.ARB_query_buffer_object &&
  62        brw_is_query_pipelined(query)) {
  63       brw_emit_pipe_control_write(brw,
  64                                   PIPE_CONTROL_WRITE_IMMEDIATE,
  65                                   query->bo, 2 * sizeof(uint64_t),
  66                                   available, 0);
  67    }
  68 }
  69
  70 static void
  71 write_primitives_generated(struct brw_context *brw,
  72                            drm_intel_bo *query_bo, int stream, int idx)
  73 {
  74    brw_emit_mi_flush(brw);
  75
  76    if (brw->gen >= 7 && stream > 0) {
  77       brw_store_register_mem64(brw, query_bo,
  78                                GEN7_SO_PRIM_STORAGE_NEEDED(stream),
  79                                idx * sizeof(uint64_t));
  80    } else {
  81       brw_store_register_mem64(brw, query_bo, CL_INVOCATION_COUNT,
  82                                idx * sizeof(uint64_t));
  83    }
  84 }
  85
  86 static void
  87 write_xfb_primitives_written(struct brw_context *brw,
  88                              drm_intel_bo *bo, int stream, int idx)
  89 {
  90    brw_emit_mi_flush(brw);
  91
  92    if (brw->gen >= 7) {
  93       brw_store_register_mem64(brw, bo, GEN7_SO_NUM_PRIMS_WRITTEN(stream),
  94                                idx * sizeof(uint64_t));
  95    } else {
  96       brw_store_register_mem64(brw, bo, GEN6_SO_NUM_PRIMS_WRITTEN,
  97                                idx * sizeof(uint64_t));
  98    }
  99 }
 100
 101 static inline int
 102 pipeline_target_to_index(int target)
 103 {
 104    if (target == GL_GEOMETRY_SHADER_INVOCATIONS)
 105       return MAX_PIPELINE_STATISTICS - 1;
 106    else
 107       return target - GL_VERTICES_SUBMITTED_ARB;
 108 }
 109
 110 static void
 111 emit_pipeline_stat(struct brw_context *brw, drm_intel_bo *bo,
 112                    int stream, int target, int idx)
 113 {
 114    /* One source of confusion is the tessellation shader statistics. The
 115     * hardware has no statistics specific to the TE unit. Ideally we could have
 116     * the HS primitives for TESS_CONTROL_SHADER_PATCHES_ARB, and the DS
 117     * invocations as the register for TESS_CONTROL_SHADER_PATCHES_ARB.
 118     * Unfortunately we don't have HS primitives, we only have HS invocations.
 119     */
 120
 121    /* Everything except GEOMETRY_SHADER_INVOCATIONS can be kept in a simple
 122     * lookup table
 123     */
 124    static const uint32_t target_to_register[] = {
 125       IA_VERTICES_COUNT,   /* VERTICES_SUBMITTED */
 126       IA_PRIMITIVES_COUNT, /* PRIMITIVES_SUBMITTED */
 127       VS_INVOCATION_COUNT, /* VERTEX_SHADER_INVOCATIONS */
 128       HS_INVOCATION_COUNT, /* TESS_CONTROL_SHADER_PATCHES */
 129       DS_INVOCATION_COUNT, /* TESS_EVALUATION_SHADER_INVOCATIONS */
 130       GS_PRIMITIVES_COUNT, /* GEOMETRY_SHADER_PRIMITIVES_EMITTED */
 131       PS_INVOCATION_COUNT, /* FRAGMENT_SHADER_INVOCATIONS */
 132       CS_INVOCATION_COUNT, /* COMPUTE_SHADER_INVOCATIONS */
 133       CL_INVOCATION_COUNT, /* CLIPPING_INPUT_PRIMITIVES */
 134       CL_PRIMITIVES_COUNT, /* CLIPPING_OUTPUT_PRIMITIVES */
 135       GS_INVOCATION_COUNT /* This one is special... */
 136    };
 137    STATIC_ASSERT(ARRAY_SIZE(target_to_register) == MAX_PIPELINE_STATISTICS);
 138    uint32_t reg = target_to_register[pipeline_target_to_index(target)];
 139    /* Gen6 GS code counts full primitives, that is, it won't count individual
 140     * triangles in a triangle strip. Use CL_INVOCATION_COUNT for that.
 141     */
 142    if (brw->gen == 6 && target == GL_GEOMETRY_SHADER_PRIMITIVES_EMITTED_ARB)
 143       reg = CL_INVOCATION_COUNT;
 144    assert(reg != 0);
 145
 146    /* Emit a flush to make sure various parts of the pipeline are complete and
 147     * we get an accurate value
 148     */
 149    brw_emit_mi_flush(brw);
 150
 151    brw_store_register_mem64(brw, bo, reg, idx * sizeof(uint64_t));
 152 }
 153
 154
 155 /**
 156  * Wait on the query object's BO and calculate the final result.
 157  */
 158 static void
 159 gen6_queryobj_get_results(struct gl_context *ctx,
 160                           struct brw_query_object *query)
 161 {
 162    struct brw_context *brw = brw_context(ctx);
 163
 164    if (query->bo == NULL)
 165       return;
 166
 167    brw_bo_map(brw, query->bo, false, "query object");
 168    uint64_t *results = query->bo->virtual;
 169    switch (query->Base.Target) {
 170    case GL_TIME_ELAPSED:
 171       /* The query BO contains the starting and ending timestamps.
 172        * Subtract the two and convert to nanoseconds.
 173        */
 174       query->Base.Result += 80 * (results[1] - results[0]);
 175       break;
 176
 177    case GL_TIMESTAMP:
 178       /* Our timer is a clock that increments every 80ns (regardless of
 179        * other clock scaling in the system).  The timestamp register we can
 180        * read for glGetTimestamp() masks out the top 32 bits, so we do that
 181        * here too to let the two counters be compared against each other.
 182        *
 183        * If we just multiplied that 32 bits of data by 80, it would roll
 184        * over at a non-power-of-two, so an application couldn't use
 185        * GL_QUERY_COUNTER_BITS to handle rollover correctly.  Instead, we
 186        * report 36 bits and truncate at that (rolling over 5 times as often
 187        * as the HW counter), and when the 32-bit counter rolls over, it
 188        * happens to also be at a rollover in the reported value from near
 189        * (1<<36) to 0.
 190        *
 191        * The low 32 bits rolls over in ~343 seconds.  Our 36-bit result
 192        * rolls over every ~69 seconds.
 193        *
 194        * The query BO contains a single timestamp value in results[0].
 195        */
 196       query->Base.Result = 80 * (results[0] & 0xffffffff);
 197       query->Base.Result &= (1ull << 36) - 1;
 198       break;
 199
 200    case GL_SAMPLES_PASSED_ARB:
 201       /* We need to use += rather than = here since some BLT-based operations
 202        * may have added additional samples to our occlusion query value.
 203        */
 204       query->Base.Result += results[1] - results[0];
 205       break;
 206
 207    case GL_ANY_SAMPLES_PASSED:
 208    case GL_ANY_SAMPLES_PASSED_CONSERVATIVE:
 209       if (results[0] != results[1])
 210          query->Base.Result = true;
 211       break;
 212
 213    case GL_PRIMITIVES_GENERATED:
 214    case GL_TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN:
 215    case GL_VERTICES_SUBMITTED_ARB:
 216    case GL_PRIMITIVES_SUBMITTED_ARB:
 217    case GL_VERTEX_SHADER_INVOCATIONS_ARB:
 218    case GL_GEOMETRY_SHADER_INVOCATIONS:
 219    case GL_GEOMETRY_SHADER_PRIMITIVES_EMITTED_ARB:
 220    case GL_CLIPPING_INPUT_PRIMITIVES_ARB:
 221    case GL_CLIPPING_OUTPUT_PRIMITIVES_ARB:
 222    case GL_COMPUTE_SHADER_INVOCATIONS_ARB:
 223    case GL_TESS_CONTROL_SHADER_PATCHES_ARB:
 224    case GL_TESS_EVALUATION_SHADER_INVOCATIONS_ARB:
 225       query->Base.Result = results[1] - results[0];
 226       break;
 227
 228    case GL_FRAGMENT_SHADER_INVOCATIONS_ARB:
 229       query->Base.Result = (results[1] - results[0]);
 230       /* Implement the "WaDividePSInvocationCountBy4:HSW,BDW" workaround:
 231        * "Invocation counter is 4 times actual.  WA: SW to divide HW reported
 232        *  PS Invocations value by 4."
 233        *
 234        * Prior to Haswell, invocation count was counted by the WM, and it
 235        * buggily counted invocations in units of subspans (2x2 unit). To get the
 236        * correct value, the CS multiplied this by 4. With HSW the logic moved,
 237        * and correctly emitted the number of pixel shader invocations, but,
 238        * whomever forgot to undo the multiply by 4.
 239        */
 240       if (brw->gen == 8 || brw->is_haswell)
 241          query->Base.Result /= 4;
 242       break;
 243
 244    default:
 245       unreachable("Unrecognized query target in brw_queryobj_get_results()");
 246    }
 247    drm_intel_bo_unmap(query->bo);
 248
 249    /* Now that we've processed the data stored in the query's buffer object,
 250     * we can release it.
 251     */
 252    drm_intel_bo_unreference(query->bo);
 253    query->bo = NULL;
 254
 255    query->Base.Ready = true;
 256 }
 257
 258 /**
 259  * Driver hook for glBeginQuery().
 260  *
 261  * Initializes driver structures and emits any GPU commands required to begin
 262  * recording data for the query.
 263  */
 264 static void
 265 gen6_begin_query(struct gl_context *ctx, struct gl_query_object *q)
 266 {
 267    struct brw_context *brw = brw_context(ctx);
 268    struct brw_query_object *query = (struct brw_query_object *)q;
 269
 270    /* Since we're starting a new query, we need to throw away old results. */
 271    drm_intel_bo_unreference(query->bo);
 272    query->bo = drm_intel_bo_alloc(brw->bufmgr, "query results", 4096, 4096);
 273
 274    /* For ARB_query_buffer_object: The result is not available */
 275    set_query_availability(brw, query, false);
 276
 277    switch (query->Base.Target) {
 278    case GL_TIME_ELAPSED:
 279       /* For timestamp queries, we record the starting time right away so that
 280        * we measure the full time between BeginQuery and EndQuery.  There's
 281        * some debate about whether this is the right thing to do.  Our decision
 282        * is based on the following text from the ARB_timer_query extension:
 283        *
 284        * "(5) Should the extension measure total time elapsed between the full
 285        *      completion of the BeginQuery and EndQuery commands, or just time
 286        *      spent in the graphics library?
 287        *
 288        *  RESOLVED:  This extension will measure the total time elapsed
 289        *  between the full completion of these commands.  Future extensions
 290        *  may implement a query to determine time elapsed at different stages
 291        *  of the graphics pipeline."
 292        *
 293        * We write a starting timestamp now (at index 0).  At EndQuery() time,
 294        * we'll write a second timestamp (at index 1), and subtract the two to
 295        * obtain the time elapsed.  Notably, this includes time elapsed while
 296        * the system was doing other work, such as running other applications.
 297        */
 298       brw_write_timestamp(brw, query->bo, 0);
 299       break;
 300
 301    case GL_ANY_SAMPLES_PASSED:
 302    case GL_ANY_SAMPLES_PASSED_CONSERVATIVE:
 303    case GL_SAMPLES_PASSED_ARB:
 304       brw_write_depth_count(brw, query->bo, 0);
 305       break;
 306
 307    case GL_PRIMITIVES_GENERATED:
 308       write_primitives_generated(brw, query->bo, query->Base.Stream, 0);
 309       if (query->Base.Stream == 0)
 310          ctx->NewDriverState |= BRW_NEW_RASTERIZER_DISCARD;
 311       break;
 312
 313    case GL_TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN:
 314       write_xfb_primitives_written(brw, query->bo, query->Base.Stream, 0);
 315       break;
 316
 317    case GL_VERTICES_SUBMITTED_ARB:
 318    case GL_PRIMITIVES_SUBMITTED_ARB:
 319    case GL_VERTEX_SHADER_INVOCATIONS_ARB:
 320    case GL_GEOMETRY_SHADER_INVOCATIONS:
 321    case GL_GEOMETRY_SHADER_PRIMITIVES_EMITTED_ARB:
 322    case GL_FRAGMENT_SHADER_INVOCATIONS_ARB:
 323    case GL_CLIPPING_INPUT_PRIMITIVES_ARB:
 324    case GL_CLIPPING_OUTPUT_PRIMITIVES_ARB:
 325    case GL_COMPUTE_SHADER_INVOCATIONS_ARB:
 326    case GL_TESS_CONTROL_SHADER_PATCHES_ARB:
 327    case GL_TESS_EVALUATION_SHADER_INVOCATIONS_ARB:
 328       emit_pipeline_stat(brw, query->bo, query->Base.Stream, query->Base.Target, 0);
 329       break;
 330
 331    default:
 332       unreachable("Unrecognized query target in brw_begin_query()");
 333    }
 334 }
 335
 336 /**
 337  * Driver hook for glEndQuery().
 338  *
 339  * Emits GPU commands to record a final query value, ending any data capturing.
 340  * However, the final result isn't necessarily available until the GPU processes
 341  * those commands.  brw_queryobj_get_results() processes the captured data to
 342  * produce the final result.
 343  */
 344 static void
 345 gen6_end_query(struct gl_context *ctx, struct gl_query_object *q)
 346 {
 347    struct brw_context *brw = brw_context(ctx);
 348    struct brw_query_object *query = (struct brw_query_object *)q;
 349
 350    switch (query->Base.Target) {
 351    case GL_TIME_ELAPSED:
 352       brw_write_timestamp(brw, query->bo, 1);
 353       break;
 354
 355    case GL_ANY_SAMPLES_PASSED:
 356    case GL_ANY_SAMPLES_PASSED_CONSERVATIVE:
 357    case GL_SAMPLES_PASSED_ARB:
 358       brw_write_depth_count(brw, query->bo, 1);
 359       break;
 360
 361    case GL_PRIMITIVES_GENERATED:
 362       write_primitives_generated(brw, query->bo, query->Base.Stream, 1);
 363       if (query->Base.Stream == 0)
 364          ctx->NewDriverState |= BRW_NEW_RASTERIZER_DISCARD;
 365       break;
 366
 367    case GL_TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN:
 368       write_xfb_primitives_written(brw, query->bo, query->Base.Stream, 1);
 369       break;
 370
 371    case GL_VERTICES_SUBMITTED_ARB:
 372    case GL_PRIMITIVES_SUBMITTED_ARB:
 373    case GL_VERTEX_SHADER_INVOCATIONS_ARB:
 374    case GL_GEOMETRY_SHADER_PRIMITIVES_EMITTED_ARB:
 375    case GL_FRAGMENT_SHADER_INVOCATIONS_ARB:
 376    case GL_COMPUTE_SHADER_INVOCATIONS_ARB:
 377    case GL_CLIPPING_INPUT_PRIMITIVES_ARB:
 378    case GL_CLIPPING_OUTPUT_PRIMITIVES_ARB:
 379    case GL_GEOMETRY_SHADER_INVOCATIONS:
 380    case GL_TESS_CONTROL_SHADER_PATCHES_ARB:
 381    case GL_TESS_EVALUATION_SHADER_INVOCATIONS_ARB:
 382       emit_pipeline_stat(brw, query->bo,
 383                          query->Base.Stream, query->Base.Target, 1);
 384       break;
 385
 386    default:
 387       unreachable("Unrecognized query target in brw_end_query()");
 388    }
 389
 390    /* The current batch contains the commands to handle EndQuery(),
 391     * but they won't actually execute until it is flushed.
 392     */
 393    query->flushed = false;
 394
 395    /* For ARB_query_buffer_object: The result is now available */
 396    set_query_availability(brw, query, true);
 397 }
 398
 399 /**
 400  * Flush the batch if it still references the query object BO.
 401  */
 402 static void
 403 flush_batch_if_needed(struct brw_context *brw, struct brw_query_object *query)
 404 {
 405    /* If the batch doesn't reference the BO, it must have been flushed
 406     * (for example, due to being full).  Record that it's been flushed.
 407     */
 408    query->flushed = query->flushed ||
 409       !drm_intel_bo_references(brw->batch.bo, query->bo);
 410
 411    if (!query->flushed)
 412       intel_batchbuffer_flush(brw);
 413 }
 414
 415 /**
 416  * The WaitQuery() driver hook.
 417  *
 418  * Wait for a query result to become available and return it.  This is the
 419  * backing for glGetQueryObjectiv() with the GL_QUERY_RESULT pname.
 420  */
 421 static void gen6_wait_query(struct gl_context *ctx, struct gl_query_object *q)
 422 {
 423    struct brw_context *brw = brw_context(ctx);
 424    struct brw_query_object *query = (struct brw_query_object *)q;
 425
 426    /* If the application has requested the query result, but this batch is
 427     * still contributing to it, flush it now to finish that work so the
 428     * result will become available (eventually).
 429     */
 430    flush_batch_if_needed(brw, query);
 431
 432    gen6_queryobj_get_results(ctx, query);
 433 }
 434
 435 /**
 436  * The CheckQuery() driver hook.
 437  *
 438  * Checks whether a query result is ready yet.  If not, flushes.
 439  * This is the backing for glGetQueryObjectiv()'s QUERY_RESULT_AVAILABLE pname.
 440  */
 441 static void gen6_check_query(struct gl_context *ctx, struct gl_query_object *q)
 442 {
 443    struct brw_context *brw = brw_context(ctx);
 444    struct brw_query_object *query = (struct brw_query_object *)q;
 445
 446    /* If query->bo is NULL, we've already gathered the results - this is a
 447     * redundant CheckQuery call.  Ignore it.
 448     */
 449    if (query->bo == NULL)
 450       return;
 451
 452    /* From the GL_ARB_occlusion_query spec:
 453     *
 454     *     "Instead of allowing for an infinite loop, performing a
 455     *      QUERY_RESULT_AVAILABLE_ARB will perform a flush if the result is
 456     *      not ready yet on the first time it is queried.  This ensures that
 457     *      the async query will return true in finite time.
 458     */
 459    flush_batch_if_needed(brw, query);
 460
 461    if (!drm_intel_bo_busy(query->bo)) {
 462       gen6_queryobj_get_results(ctx, query);
 463    }
 464 }
 465
 466 static void
 467 gen6_query_counter(struct gl_context *ctx, struct gl_query_object *q)
 468 {
 469    struct brw_context *brw = brw_context(ctx);
 470    struct brw_query_object *query = (struct brw_query_object *)q;
 471    brw_query_counter(ctx, q);
 472    set_query_availability(brw, query, true);
 473 }
 474
 475 /* Initialize Gen6+-specific query object functions. */
 476 void gen6_init_queryobj_functions(struct dd_function_table *functions)
 477 {
 478    functions->BeginQuery = gen6_begin_query;
 479    functions->EndQuery = gen6_end_query;
 480    functions->CheckQuery = gen6_check_query;
 481    functions->WaitQuery = gen6_wait_query;
 482    functions->QueryCounter = gen6_query_counter;
 483 }