/*
* 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@anholt.net>
* Kenneth Graunke <kenneth@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 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)
{
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;
}