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/*

 * 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 

 *    Kenneth Graunke 

 */

/** @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 brw_context *brw, drm_intel_bo *query_bo, int idx)

{

   /* Emit workaround flushes: */

   if (brw->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 brw_context *brw, drm_intel_bo *query_bo, int idx)

{

   /* Emit Sandybridge workaround flush: */

   if (brw->gen == 6)

      intel_emit_post_sync_nonzero_flush(brw);

   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();

}

/*

 * Write an arbitrary 64-bit register to a buffer via MI_STORE_REGISTER_MEM.

 *

 * Only TIMESTAMP and PS_DEPTH_COUNT have special PIPE_CONTROL support; other

 * counters have to be read via the generic MI_STORE_REGISTER_MEM.  This

 * function also performs a pipeline flush for proper synchronization.

 */

static void

write_reg(struct brw_context *brw,

          drm_intel_bo *query_bo, uint32_t reg, int idx)

{

   assert(brw->gen >= 6);

   intel_batchbuffer_emit_mi_flush(brw);

   /* MI_STORE_REGISTER_MEM only stores a single 32-bit value, so to

    * read a full 64-bit register, we need to do two of them.

    */

   BEGIN_BATCH(3);

   OUT_BATCH(MI_STORE_REGISTER_MEM | (3 - 2));

   OUT_BATCH(reg);

   OUT_RELOC(query_bo, I915_GEM_DOMAIN_RENDER, I915_GEM_DOMAIN_RENDER,

             idx * sizeof(uint64_t));

   ADVANCE_BATCH();

   BEGIN_BATCH(3);

   OUT_BATCH(MI_STORE_REGISTER_MEM | (3 - 2));

   OUT_BATCH(reg + sizeof(uint32_t));

   OUT_RELOC(query_bo, I915_GEM_DOMAIN_RENDER, I915_GEM_DOMAIN_RENDER,

             sizeof(uint32_t) + idx * sizeof(uint64_t));

   ADVANCE_BATCH();

}

static void

write_primitives_generated(struct brw_context *brw,

                           drm_intel_bo *query_bo, int idx)

{

   write_reg(brw, query_bo, CL_INVOCATION_COUNT, idx);

}

static void

write_xfb_primitives_written(struct brw_context *brw,

                             drm_intel_bo *query_bo, int idx)

{

   if (brw->gen >= 7) {

      write_reg(brw, query_bo, SO_NUM_PRIMS_WRITTEN0_IVB, idx);

   } else {

      write_reg(brw, query_bo, SO_NUM_PRIMS_WRITTEN, idx);

   }

}

/**

 * 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 brw_context *brw = brw_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(brw->batch.bo, query->bo))

      intel_batchbuffer_flush(brw);

   if (unlikely(brw->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:

      /* We need to use += rather than = here since some BLT-based operations

       * may have added additional samples to our occlusion query value.

       */

      query->Base.Result += results[1] - results[0];

      break;

   case GL_ANY_SAMPLES_PASSED:

   case GL_ANY_SAMPLES_PASSED_CONSERVATIVE:

      if (results[0] != results[1])

         query->Base.Result = true;

      break;

   case GL_PRIMITIVES_GENERATED:

   case GL_TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN:

      query->Base.Result = results[1] - results[0];

      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 brw_query_object *query = (struct brw_query_object *)q;

   /* Since we're starting a new query, we need to throw away old results. */

   drm_intel_bo_unreference(query->bo);

   query->bo = drm_intel_bo_alloc(brw->bufmgr, "query results", 4096, 4096);

   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.

       */

      write_timestamp(brw, query->bo, 0);

      break;

   case GL_ANY_SAMPLES_PASSED:

   case GL_ANY_SAMPLES_PASSED_CONSERVATIVE:

   case GL_SAMPLES_PASSED_ARB:

      write_depth_count(brw, query->bo, 0);

      break;

   case GL_PRIMITIVES_GENERATED:

      write_primitives_generated(brw, query->bo, 0);

      break;

   case GL_TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN:

      write_xfb_primitives_written(brw, query->bo, 0);

      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 brw_query_object *query = (struct brw_query_object *)q;

   switch (query->Base.Target) {

   case GL_TIME_ELAPSED:

      write_timestamp(brw, query->bo, 1);

      break;

   case GL_ANY_SAMPLES_PASSED:

   case GL_ANY_SAMPLES_PASSED_CONSERVATIVE:

   case GL_SAMPLES_PASSED_ARB:

      write_depth_count(brw, query->bo, 1);

      break;

   case GL_PRIMITIVES_GENERATED:

      write_primitives_generated(brw, query->bo, 1);

      break;

   case GL_TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN:

      write_xfb_primitives_written(brw, query->bo, 1);

      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 brw_context *brw = brw_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(brw->batch.bo, query->bo))

      intel_batchbuffer_flush(brw);

   if (query->bo == NULL || !drm_intel_bo_busy(query->bo)) {

      gen6_queryobj_get_results(ctx, query);

      query->Base.Ready = true;

   }

}

/* Initialize Gen6+-specific query object functions. */

void gen6_init_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;

}