[Mesa-dev] [PATCH 05/10] i965: Rely on hardware contexts for query objects on Gen6+.

Paul Berry stereotype441 at gmail.com
Mon May 20 10:31:47 PDT 2013


On 17 May 2013 10:17, Kenneth Graunke <kenneth at whitecape.org> wrote:

> Hardware contexts greatly simplify the query object code.  The pipeline
> statistics counters get saved and restored with the context, which means
> that we don't need to worry about other workloads polluting them.
>
> This means that we can simply write a single pair of values (one at
> BeginQuery and one at EndQuery) rather than a series of pairs.  This
> also means we don't need to worry about the BO getting full.  We also
> don't need to delay BO allocation and starting snapshot until the first
> draw.
>
> The generation split here is a little off: technically, Ironlake can also
> support hardware contexts.  However, the kernel currently doesn't, and
> even if it were to do so someday, we'd need to wait a while before
> bumping the kernel requirement to take advantage of it.
>
> Cc: Eric Anholt <eric at anholt.net>
> Cc: Paul Berry <stereotype441 at gmail.com>
> Signed-off-by: Kenneth Graunke <kenneth at whitecape.org>
> ---
>  src/mesa/drivers/dri/i965/Makefile.sources |   1 +
>  src/mesa/drivers/dri/i965/brw_context.c    |   2 +
>  src/mesa/drivers/dri/i965/brw_context.h    |   3 +
>  src/mesa/drivers/dri/i965/brw_queryobj.c   |  83 ++-----
>  src/mesa/drivers/dri/i965/gen6_queryobj.c  | 354
> +++++++++++++++++++++++++++++
>  5 files changed, 383 insertions(+), 60 deletions(-)
>  create mode 100644 src/mesa/drivers/dri/i965/gen6_queryobj.c
>
> diff --git a/src/mesa/drivers/dri/i965/Makefile.sources
> b/src/mesa/drivers/dri/i965/Makefile.sources
> index a0ffd3a..d67a5a4 100644
> --- a/src/mesa/drivers/dri/i965/Makefile.sources
> +++ b/src/mesa/drivers/dri/i965/Makefile.sources
> @@ -104,6 +104,7 @@ i965_FILES = \
>         gen6_depthstencil.c \
>         gen6_gs_state.c \
>          gen6_multisample_state.c \
> +       gen6_queryobj.c \
>         gen6_sampler_state.c \
>         gen6_scissor_state.c \
>         gen6_sf_state.c \
> diff --git a/src/mesa/drivers/dri/i965/brw_context.c
> b/src/mesa/drivers/dri/i965/brw_context.c
> index 2f5fedb..beade5c 100644
> --- a/src/mesa/drivers/dri/i965/brw_context.c
> +++ b/src/mesa/drivers/dri/i965/brw_context.c
> @@ -88,6 +88,8 @@ static void brwInitDriverFunctions(struct intel_screen
> *screen,
>
>     brwInitFragProgFuncs( functions );
>     brw_init_queryobj_functions(functions);
> +   if (screen->gen >= 6)
> +      gen6_reinit_queryobj_functions(functions);
>

I find it confusing that we initialize the queryobj function pointers to
the pre-gen6 functions and then immediately override some of them to gen6+
versions.

How about splitting brw_init_queryobj_functions() into
brw_init_common_queryobj_functions() and
brw_init_pre_gen6_queryobj_functions(), and renaming
gen6_reinit_queryobj_functions() to just gen6_init_queryobj_functions()?

Then this code would change to:

brw_init_common_queryobj_functions()
if (screen->gen < 6)
   brw_init_pre_gen6_queryobj_functions()
else
   gen6_init_queryobj_functions()


>
>     functions->QuerySamplesForFormat = brw_query_samples_for_format;
>     functions->BeginTransformFeedback = brw_begin_transform_feedback;
> diff --git a/src/mesa/drivers/dri/i965/brw_context.h
> b/src/mesa/drivers/dri/i965/brw_context.h
> index 9baf57b..9ef6aca 100644
> --- a/src/mesa/drivers/dri/i965/brw_context.h
> +++ b/src/mesa/drivers/dri/i965/brw_context.h
> @@ -1164,6 +1164,9 @@ void brw_init_queryobj_functions(struct
> dd_function_table *functions);
>  void brw_emit_query_begin(struct brw_context *brw);
>  void brw_emit_query_end(struct brw_context *brw);
>
> +/** gen6_queryobj.c */
> +void gen6_reinit_queryobj_functions(struct dd_function_table *functions);
> +
>  /*======================================================================
>   * brw_state_dump.c
>   */
> diff --git a/src/mesa/drivers/dri/i965/brw_queryobj.c
> b/src/mesa/drivers/dri/i965/brw_queryobj.c
> index 40f926b..1c1e0b4 100644
> --- a/src/mesa/drivers/dri/i965/brw_queryobj.c
> +++ b/src/mesa/drivers/dri/i965/brw_queryobj.c
>

So is brw_queryobj.c now for pre-Gen6 only?  If so, can we please add a
comment to that effect at the top of the file, and remove the remaining
intel->gen checks (e.g. in write_timestamp())?  If not, can we somehow
document which functions are Pre-gen6 and which aren't (e.g. with
"assert(intel->gen < 6);" at the top of the pre-gen6 functions)?  As it
stands this patch leaves the file in a condition where it's hard to tell
without a deep understanding of the driver which functions are for which
chip generations.


> @@ -94,40 +94,21 @@ write_timestamp(struct intel_context *intel,
> drm_intel_bo *query_bo, int idx)
>  static void
>  write_depth_count(struct intel_context *intel, drm_intel_bo *query_bo,
> int idx)
>  {
>
-   if (intel->gen >= 6) {
> -      /* Emit Sandybridge workaround flush: */
> -      if (intel->gen == 6)
> -         intel_emit_post_sync_nonzero_flush(intel);
> -
> -      BEGIN_BATCH(5);
> -      OUT_BATCH(_3DSTATE_PIPE_CONTROL | (5 - 2));
> -      OUT_BATCH(PIPE_CONTROL_DEPTH_STALL |
> -                PIPE_CONTROL_WRITE_DEPTH_COUNT);
> -      OUT_RELOC(query_bo,
> -                I915_GEM_DOMAIN_INSTRUCTION, I915_GEM_DOMAIN_INSTRUCTION,
> -                PIPE_CONTROL_GLOBAL_GTT_WRITE |
> -                (idx * sizeof(uint64_t)));
> -      OUT_BATCH(0);
> -      OUT_BATCH(0);
> -      ADVANCE_BATCH();
> -   } else {
> -      BEGIN_BATCH(4);
> -      OUT_BATCH(_3DSTATE_PIPE_CONTROL | (4 - 2) |
> -                PIPE_CONTROL_DEPTH_STALL |
> -                PIPE_CONTROL_WRITE_DEPTH_COUNT);
> -      /* This object could be mapped cacheable, but we don't have an
> exposed
> -       * mechanism to support that.  Since it's going uncached, tell GEM
> that
> -       * we're writing to it.  The usual clflush should be all that's
> required
> -       * to pick up the results.
> -       */
> -      OUT_RELOC(query_bo,
> -                I915_GEM_DOMAIN_INSTRUCTION, I915_GEM_DOMAIN_INSTRUCTION,
> -                PIPE_CONTROL_GLOBAL_GTT_WRITE |
> -                (idx * sizeof(uint64_t)));
> -      OUT_BATCH(0);
> -      OUT_BATCH(0);
> -      ADVANCE_BATCH();
> -   }
> +   BEGIN_BATCH(4);
> +   OUT_BATCH(_3DSTATE_PIPE_CONTROL | (4 - 2) |
> +             PIPE_CONTROL_DEPTH_STALL | PIPE_CONTROL_WRITE_DEPTH_COUNT);
> +   /* This object could be mapped cacheable, but we don't have an exposed
> +    * mechanism to support that.  Since it's going uncached, tell GEM that
> +    * we're writing to it.  The usual clflush should be all that's
> required
> +    * to pick up the results.
> +    */
> +   OUT_RELOC(query_bo,
> +             I915_GEM_DOMAIN_INSTRUCTION, I915_GEM_DOMAIN_INSTRUCTION,
> +             PIPE_CONTROL_GLOBAL_GTT_WRITE |
> +             (idx * sizeof(uint64_t)));
> +   OUT_BATCH(0);
> +   OUT_BATCH(0);
> +   ADVANCE_BATCH();
>  }
>
>  /**
> @@ -165,36 +146,12 @@ brw_queryobj_get_results(struct gl_context *ctx,
>        /* The query BO contains the starting and ending timestamps.
>         * Subtract the two and convert to nanoseconds.
>         */
> -      if (intel->gen >= 6)
> -        query->Base.Result += 80 * (results[1] - results[0]);
> -      else
> -        query->Base.Result += 1000 * ((results[1] >> 32) - (results[0] >>
> 32));
> +      query->Base.Result += 1000 * ((results[1] >> 32) - (results[0] >>
> 32));
>        break;
>
>     case GL_TIMESTAMP:
>        /* The query BO contains a single timestamp value in results[0]. */
> -      if (intel->gen >= 6) {
> -         /* Our timer is a clock that increments every 80ns (regardless of
> -          * other clock scaling in the system).  The timestamp register
> we can
> -          * read for glGetTimestamp() masks out the top 32 bits, so we do
> that
> -          * here too to let the two counters be compared against each
> other.
> -          *
> -          * If we just multiplied that 32 bits of data by 80, it would
> roll
> -          * over at a non-power-of-two, so an application couldn't use
> -          * GL_QUERY_COUNTER_BITS to handle rollover correctly.  Instead,
> we
> -          * report 36 bits and truncate at that (rolling over 5 times as
> often
> -          * as the HW counter), and when the 32-bit counter rolls over, it
> -          * happens to also be at a rollover in the reported value from
> near
> -          * (1<<36) to 0.
> -          *
> -          * The low 32 bits rolls over in ~343 seconds.  Our 36-bit result
> -          * rolls over every ~69 seconds.
> -          */
> -        query->Base.Result = 80 * (results[0] & 0xffffffff);
> -         query->Base.Result &= (1ull << 36) - 1;
> -      } else {
> -        query->Base.Result = 1000 * (results[0] >> 32);
> -      }
> +      query->Base.Result = 1000 * (results[0] >> 32);
>        break;
>
>     case GL_SAMPLES_PASSED_ARB:
>

Below this code, in the GL_PRIMITIVES_GENERATED and
GL_TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN cases, can we change the comment
so that instead of saying "We don't actually query the hardware for this
value, so query->bo should always be NULL and execution should never reach
here." it says something like "Transform feedback isn't supported pre-gen6"?

Similarly, there's code in brw_begin_query() and brw_end_query() for
handling GL_PRIMITIVES_GENERATED and
GL_TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN that is now unreachable because we
don't support transform feedback prior to Gen6.  I think we should replace
it with a comment to that affect and an assertion.



> @@ -545,6 +502,9 @@ brw_emit_query_begin(struct brw_context *brw)
>     struct gl_context *ctx = &intel->ctx;
>     struct brw_query_object *query = brw->query.obj;
>
> +   if (intel->hw_ctx)
> +      return;
> +
>

The comment above brw_emit_query_begin() says that we record PS_DEPTH_COUNT
at the beginning and end of each batch, regardless of whether hardware
contexts are in use.  Can we please change the comment to reflect the new
behaviour?

    /* Skip if we're not doing any queries, or we've already recorded the
>      * initial query value for this batchbuffer.
>      */
> @@ -569,6 +529,9 @@ brw_emit_query_end(struct brw_context *brw)
>     struct intel_context *intel = &brw->intel;
>     struct brw_query_object *query = brw->query.obj;
>
> +   if (intel->hw_ctx)
> +      return;
> +
>     if (!brw->query.begin_emitted)
>        return;
>
> diff --git a/src/mesa/drivers/dri/i965/gen6_queryobj.c
> b/src/mesa/drivers/dri/i965/gen6_queryobj.c
> new file mode 100644
> index 0000000..28af8d7
> --- /dev/null
> +++ b/src/mesa/drivers/dri/i965/gen6_queryobj.c
> @@ -0,0 +1,354 @@
> +/*
> + * Copyright © 2008 Intel Corporation
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a
> + * copy of this software and associated documentation files (the
> "Software"),
> + * to deal in the Software without restriction, including without
> limitation
> + * the rights to use, copy, modify, merge, publish, distribute,
> sublicense,
> + * and/or sell copies of the Software, and to permit persons to whom the
> + * Software is furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice (including the
> next
> + * paragraph) shall be included in all copies or substantial portions of
> the
> + * Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
> EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
> MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT
> SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
> OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
> + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
> DEALINGS
> + * IN THE SOFTWARE.
> + *
> + * Authors:
> + *    Eric Anholt <eric at anholt.net>
> + *    Kenneth Graunke <kenneth at whitecape.org>
> + */
> +
> +/** @file gen6_queryobj.c
> + *
> + * Support for query objects (GL_ARB_occlusion_query, GL_ARB_timer_query,
> + * GL_EXT_transform_feedback, and friends) on platforms that support
> + * hardware contexts (Gen6+).
> + */
> +#include "main/imports.h"
> +
> +#include "brw_context.h"
> +#include "brw_defines.h"
> +#include "brw_state.h"
> +#include "intel_batchbuffer.h"
> +#include "intel_reg.h"
> +
> +/**
> + * Emit PIPE_CONTROLs to write the current GPU timestamp into a buffer.
> + */
> +static void
> +write_timestamp(struct intel_context *intel, drm_intel_bo *query_bo, int
> idx)
> +{
> +   /* Emit workaround flushes: */
> +   if (intel->gen == 6) {
> +      /* The timestamp write below is a non-zero post-sync op, which on
> +       * Gen6 necessitates a CS stall.  CS stalls need stall at scoreboard
> +       * set.  See the comments for intel_emit_post_sync_nonzero_flush().
> +       */
> +      BEGIN_BATCH(4);
> +      OUT_BATCH(_3DSTATE_PIPE_CONTROL | (4 - 2));
> +      OUT_BATCH(PIPE_CONTROL_CS_STALL | PIPE_CONTROL_STALL_AT_SCOREBOARD);
> +      OUT_BATCH(0);
> +      OUT_BATCH(0);
> +      ADVANCE_BATCH();
> +   }
> +
> +   BEGIN_BATCH(5);
> +   OUT_BATCH(_3DSTATE_PIPE_CONTROL | (5 - 2));
> +   OUT_BATCH(PIPE_CONTROL_WRITE_TIMESTAMP);
> +   OUT_RELOC(query_bo,
> +             I915_GEM_DOMAIN_INSTRUCTION, I915_GEM_DOMAIN_INSTRUCTION,
> +             PIPE_CONTROL_GLOBAL_GTT_WRITE |
> +             idx * sizeof(uint64_t));
> +   OUT_BATCH(0);
> +   OUT_BATCH(0);
> +   ADVANCE_BATCH();
> +}
> +
> +/**
> + * Emit PIPE_CONTROLs to write the PS_DEPTH_COUNT register into a buffer.
> + */
> +static void
> +write_depth_count(struct intel_context *intel, drm_intel_bo *query_bo,
> int idx)
> +{
> +   /* Emit Sandybridge workaround flush: */
> +   if (intel->gen == 6)
> +      intel_emit_post_sync_nonzero_flush(intel);
> +
> +   BEGIN_BATCH(5);
> +   OUT_BATCH(_3DSTATE_PIPE_CONTROL | (5 - 2));
> +   OUT_BATCH(PIPE_CONTROL_DEPTH_STALL |
> +             PIPE_CONTROL_WRITE_DEPTH_COUNT);
> +   OUT_RELOC(query_bo,
> +             I915_GEM_DOMAIN_INSTRUCTION, I915_GEM_DOMAIN_INSTRUCTION,
> +             PIPE_CONTROL_GLOBAL_GTT_WRITE |
> +             (idx * sizeof(uint64_t)));
> +   OUT_BATCH(0);
> +   OUT_BATCH(0);
> +   ADVANCE_BATCH();
> +}
> +
> +/**
> + * Wait on the query object's BO and calculate the final result.
> + */
> +static void
> +gen6_queryobj_get_results(struct gl_context *ctx,
> +                          struct brw_query_object *query)
> +{
> +   struct intel_context *intel = intel_context(ctx);
> +
> +   if (query->bo == NULL)
> +      return;
> +
> +   /* If the application has requested the query result, but this batch is
> +    * still contributing to it, flush it now so the results will be
> present
> +    * when mapped.
> +    */
> +   if (drm_intel_bo_references(intel->batch.bo, query->bo))
> +      intel_batchbuffer_flush(intel);
> +
> +   if (unlikely(intel->perf_debug)) {
> +      if (drm_intel_bo_busy(query->bo)) {
> +         perf_debug("Stalling on the GPU waiting for a query object.\n");
> +      }
> +   }
> +
> +   drm_intel_bo_map(query->bo, false);
> +   uint64_t *results = query->bo->virtual;
> +   switch (query->Base.Target) {
> +   case GL_TIME_ELAPSED:
> +      /* The query BO contains the starting and ending timestamps.
> +       * Subtract the two and convert to nanoseconds.
> +       */
> +      query->Base.Result += 80 * (results[1] - results[0]);
> +      break;
> +
> +   case GL_TIMESTAMP:
> +      /* Our timer is a clock that increments every 80ns (regardless of
> +       * other clock scaling in the system).  The timestamp register we
> can
> +       * read for glGetTimestamp() masks out the top 32 bits, so we do
> that
> +       * here too to let the two counters be compared against each other.
> +       *
> +       * If we just multiplied that 32 bits of data by 80, it would roll
> +       * over at a non-power-of-two, so an application couldn't use
> +       * GL_QUERY_COUNTER_BITS to handle rollover correctly.  Instead, we
> +       * report 36 bits and truncate at that (rolling over 5 times as
> often
> +       * as the HW counter), and when the 32-bit counter rolls over, it
> +       * happens to also be at a rollover in the reported value from near
> +       * (1<<36) to 0.
> +       *
> +       * The low 32 bits rolls over in ~343 seconds.  Our 36-bit result
> +       * rolls over every ~69 seconds.
> +       *
> +       * The query BO contains a single timestamp value in results[0].
> +       */
> +      query->Base.Result = 80 * (results[0] & 0xffffffff);
> +      query->Base.Result &= (1ull << 36) - 1;
> +      break;
> +
> +   case GL_SAMPLES_PASSED_ARB:
> +      query->Base.Result += results[1] - results[0];
> +      break;
> +
> +   case GL_ANY_SAMPLES_PASSED:
> +   case GL_ANY_SAMPLES_PASSED_CONSERVATIVE:
> +      query->Base.Result = results[0] != results[1];
> +      break;
> +
> +   case GL_PRIMITIVES_GENERATED:
> +   case GL_TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN:
> +      /* We don't actually query the hardware for this value, so query->bo
> +       * should always be NULL and execution should never reach here.
> +       */
> +      assert(!"Unreachable");
> +      break;
> +
> +   default:
> +      assert(!"Unrecognized query target in brw_queryobj_get_results()");
> +      break;
> +   }
> +   drm_intel_bo_unmap(query->bo);
> +
> +   /* Now that we've processed the data stored in the query's buffer
> object,
> +    * we can release it.
> +    */
> +   drm_intel_bo_unreference(query->bo);
> +   query->bo = NULL;
> +}
> +
> +/**
> + * Driver hook for glBeginQuery().
> + *
> + * Initializes driver structures and emits any GPU commands required to
> begin
> + * recording data for the query.
> + */
> +static void
> +gen6_begin_query(struct gl_context *ctx, struct gl_query_object *q)
> +{
> +   struct brw_context *brw = brw_context(ctx);
> +   struct intel_context *intel = intel_context(ctx);
> +   struct brw_query_object *query = (struct brw_query_object *)q;
> +
> +   switch (query->Base.Target) {
> +   case GL_TIME_ELAPSED:
> +      /* For timestamp queries, we record the starting time right away so
> that
> +       * we measure the full time between BeginQuery and EndQuery.
>  There's
> +       * some debate about whether this is the right thing to do.  Our
> decision
> +       * is based on the following text from the ARB_timer_query
> extension:
> +       *
> +       * "(5) Should the extension measure total time elapsed between the
> full
> +       *      completion of the BeginQuery and EndQuery commands, or just
> time
> +       *      spent in the graphics library?
> +       *
> +       *  RESOLVED:  This extension will measure the total time elapsed
> +       *  between the full completion of these commands.  Future
> extensions
> +       *  may implement a query to determine time elapsed at different
> stages
> +       *  of the graphics pipeline."
> +       *
> +       * We write a starting timestamp now (at index 0).  At EndQuery()
> time,
> +       * we'll write a second timestamp (at index 1), and subtract the
> two to
> +       * obtain the time elapsed.  Notably, this includes time elapsed
> while
> +       * the system was doing other work, such as running other
> applications.
> +       */
> +      drm_intel_bo_unreference(query->bo);
> +      query->bo = drm_intel_bo_alloc(intel->bufmgr, "timer query", 4096,
> 4096);
> +      write_timestamp(intel, query->bo, 0);
> +      break;
> +
> +   case GL_ANY_SAMPLES_PASSED:
> +   case GL_ANY_SAMPLES_PASSED_CONSERVATIVE:
> +   case GL_SAMPLES_PASSED_ARB:
> +      /* Since we're starting a new query, we need to be sure to throw
> away
> +       * any previous occlusion query results.
> +       */
> +      drm_intel_bo_unreference(query->bo);
> +      query->bo = drm_intel_bo_alloc(intel->bufmgr, "occl. query", 4096,
> 4096);
> +      write_depth_count(intel, query->bo, 0);
> +      break;
> +
> +   case GL_PRIMITIVES_GENERATED:
> +      /* We don't actually query the hardware for this value; we keep
> track of
> +       * it a software counter.  So just reset the counter.
> +       */
> +      brw->sol.primitives_generated = 0;
> +      brw->sol.counting_primitives_generated = true;
> +      break;
> +
> +   case GL_TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN:
> +      /* We don't actually query the hardware for this value; we keep
> track of
> +       * it a software counter.  So just reset the counter.
> +       */
> +      brw->sol.primitives_written = 0;
> +      brw->sol.counting_primitives_written = true;
> +      break;
> +
> +   default:
> +      assert(!"Unrecognized query target in brw_begin_query()");
> +      break;
> +   }
> +}
> +
> +/**
> + * Driver hook for glEndQuery().
> + *
> + * Emits GPU commands to record a final query value, ending any data
> capturing.
> + * However, the final result isn't necessarily available until the GPU
> processes
> + * those commands.  brw_queryobj_get_results() processes the captured
> data to
> + * produce the final result.
> + */
> +static void
> +gen6_end_query(struct gl_context *ctx, struct gl_query_object *q)
> +{
> +   struct brw_context *brw = brw_context(ctx);
> +   struct intel_context *intel = intel_context(ctx);
> +   struct brw_query_object *query = (struct brw_query_object *)q;
> +
> +   switch (query->Base.Target) {
> +   case GL_TIME_ELAPSED:
> +      write_timestamp(intel, query->bo, 1);
> +      break;
> +
> +   case GL_ANY_SAMPLES_PASSED:
> +   case GL_ANY_SAMPLES_PASSED_CONSERVATIVE:
> +   case GL_SAMPLES_PASSED_ARB:
> +      write_depth_count(intel, query->bo, 1);
> +      break;
> +
> +   case GL_PRIMITIVES_GENERATED:
> +      /* We don't actually query the hardware for this value; we keep
> track of
> +       * it in a software counter.  So just read the counter and store it
> in
> +       * the query object.
> +       */
> +      query->Base.Result = brw->sol.primitives_generated;
> +      brw->sol.counting_primitives_generated = false;
> +      break;
> +
> +   case GL_TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN:
> +      /* We don't actually query the hardware for this value; we keep
> track of
> +       * it in a software counter.  So just read the counter and store it
> in
> +       * the query object.
> +       */
> +      query->Base.Result = brw->sol.primitives_written;
> +      brw->sol.counting_primitives_written = false;
> +      break;
> +
> +   default:
> +      assert(!"Unrecognized query target in brw_end_query()");
> +      break;
> +   }
> +}
> +
> +/**
> + * The WaitQuery() driver hook.
> + *
> + * Wait for a query result to become available and return it.  This is the
> + * backing for glGetQueryObjectiv() with the GL_QUERY_RESULT pname.
> + */
> +static void gen6_wait_query(struct gl_context *ctx, struct
> gl_query_object *q)
> +{
> +   struct brw_query_object *query = (struct brw_query_object *)q;
> +
> +   gen6_queryobj_get_results(ctx, query);
> +   query->Base.Ready = true;
> +}
> +
> +/**
> + * The CheckQuery() driver hook.
> + *
> + * Checks whether a query result is ready yet.  If not, flushes.
> + * This is the backing for glGetQueryObjectiv()'s QUERY_RESULT_AVAILABLE
> pname.
> + */
> +static void gen6_check_query(struct gl_context *ctx, struct
> gl_query_object *q)
> +{
> +   struct intel_context *intel = intel_context(ctx);
> +   struct brw_query_object *query = (struct brw_query_object *)q;
> +
> +   /* From the GL_ARB_occlusion_query spec:
> +    *
> +    *     "Instead of allowing for an infinite loop, performing a
> +    *      QUERY_RESULT_AVAILABLE_ARB will perform a flush if the result
> is
> +    *      not ready yet on the first time it is queried.  This ensures
> that
> +    *      the async query will return true in finite time.
> +    */
> +   if (query->bo && drm_intel_bo_references(intel->batch.bo, query->bo))
> +      intel_batchbuffer_flush(intel);
> +
> +   if (query->bo == NULL || !drm_intel_bo_busy(query->bo)) {
> +      gen6_queryobj_get_results(ctx, query);
> +      query->Base.Ready = true;
> +   }
> +}
> +
> +void gen6_reinit_queryobj_functions(struct dd_function_table *functions)
> +{
> +   functions->BeginQuery = gen6_begin_query;
> +   functions->EndQuery = gen6_end_query;
> +   functions->CheckQuery = gen6_check_query;
> +   functions->WaitQuery = gen6_wait_query;
> +}
> --
> 1.8.2.3
>
>
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