/*
* Copyright © 2010 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.
*/
#include "brw_context.h"
#include "brw_defines.h"
#include "intel_batchbuffer.h"
#include "intel_fbo.h"
/**
* According to the latest documentation, any PIPE_CONTROL with the
* "Command Streamer Stall" bit set must also have another bit set,
* with five different options:
*
* - Render Target Cache Flush
* - Depth Cache Flush
* - Stall at Pixel Scoreboard
* - Post-Sync Operation
* - Depth Stall
* - DC Flush Enable
*
* I chose "Stall at Pixel Scoreboard" since we've used it effectively
* in the past, but the choice is fairly arbitrary.
*/
static void
gen8_add_cs_stall_workaround_bits(uint32_t *flags)
{
uint32_t wa_bits = PIPE_CONTROL_RENDER_TARGET_FLUSH |
PIPE_CONTROL_DEPTH_CACHE_FLUSH |
PIPE_CONTROL_WRITE_IMMEDIATE |
PIPE_CONTROL_WRITE_DEPTH_COUNT |
PIPE_CONTROL_WRITE_TIMESTAMP |
PIPE_CONTROL_STALL_AT_SCOREBOARD |
PIPE_CONTROL_DEPTH_STALL |
PIPE_CONTROL_DATA_CACHE_FLUSH;
/* If we're doing a CS stall, and don't already have one of the
* workaround bits set, add "Stall at Pixel Scoreboard."
*/
if ((*flags & PIPE_CONTROL_CS_STALL) != 0 && (*flags & wa_bits) == 0)
*flags |= PIPE_CONTROL_STALL_AT_SCOREBOARD;
}
/* Implement the WaCsStallAtEveryFourthPipecontrol workaround on IVB, BYT:
*
* "Every 4th PIPE_CONTROL command, not counting the PIPE_CONTROL with
* only read-cache-invalidate bit(s) set, must have a CS_STALL bit set."
*
* Note that the kernel does CS stalls between batches, so we only need
* to count them within a batch.
*/
static uint32_t
gen7_cs_stall_every_four_pipe_controls(struct brw_context *brw, uint32_t flags)
{
if (brw->gen == 7 && !brw->is_haswell) {
if (flags & PIPE_CONTROL_CS_STALL) {
/* If we're doing a CS stall, reset the counter and carry on. */
brw->pipe_controls_since_last_cs_stall = 0;
return 0;
}
/* If this is the fourth pipe control without a CS stall, do one now. */
if (++brw->pipe_controls_since_last_cs_stall == 4) {
brw->pipe_controls_since_last_cs_stall = 0;
return PIPE_CONTROL_CS_STALL;
}
}
return 0;
}
/**
* Emit a PIPE_CONTROL with various flushing flags.
*
* The caller is responsible for deciding what flags are appropriate for the
* given generation.
*/
void
brw_emit_pipe_control_flush(struct brw_context *brw, uint32_t flags)
{
if (brw->gen >= 6 &&
(flags & PIPE_CONTROL_CACHE_FLUSH_BITS) &&
(flags & PIPE_CONTROL_CACHE_INVALIDATE_BITS)) {
/* A pipe control command with flush and invalidate bits set
* simultaneously is an inherently racy operation on Gen6+ if the
* contents of the flushed caches were intended to become visible from
* any of the invalidated caches. Split it in two PIPE_CONTROLs, the
* first one should stall the pipeline to make sure that the flushed R/W
* caches are coherent with memory once the specified R/O caches are
* invalidated. On pre-Gen6 hardware the (implicit) R/O cache
* invalidation seems to happen at the bottom of the pipeline together
* with any write cache flush, so this shouldn't be a concern.
*/
brw_emit_pipe_control_flush(brw, (flags & PIPE_CONTROL_CACHE_FLUSH_BITS) |
PIPE_CONTROL_CS_STALL);
flags &= ~(PIPE_CONTROL_CACHE_FLUSH_BITS | PIPE_CONTROL_CS_STALL);
}
if (brw->gen >= 8) {
if (brw->gen == 8)
gen8_add_cs_stall_workaround_bits(&flags);
if (brw->gen == 9 &&
(flags & PIPE_CONTROL_VF_CACHE_INVALIDATE)) {
/* Hardware workaround: SKL
*
* Emit Pipe Control with all bits set to zero before emitting
* a Pipe Control with VF Cache Invalidate set.
*/
brw_emit_pipe_control_flush(brw, 0);
}
BEGIN_BATCH(6);
OUT_BATCH(_3DSTATE_PIPE_CONTROL | (6 - 2));
OUT_BATCH(flags);
OUT_BATCH(0);
OUT_BATCH(0);
OUT_BATCH(0);
OUT_BATCH(0);
ADVANCE_BATCH();
} else if (brw->gen >= 6) {
if (brw->gen == 6 &&
(flags & PIPE_CONTROL_RENDER_TARGET_FLUSH)) {
/* Hardware workaround: SNB B-Spec says:
*
* [Dev-SNB{W/A}]: Before a PIPE_CONTROL with Write Cache Flush
* Enable = 1, a PIPE_CONTROL with any non-zero post-sync-op is
* required.
*/
brw_emit_post_sync_nonzero_flush(brw);
}
flags |= gen7_cs_stall_every_four_pipe_controls(brw, flags);
BEGIN_BATCH(5);
OUT_BATCH(_3DSTATE_PIPE_CONTROL | (5 - 2));
OUT_BATCH(flags);
OUT_BATCH(0);
OUT_BATCH(0);
OUT_BATCH(0);
ADVANCE_BATCH();
} else {
BEGIN_BATCH(4);
OUT_BATCH(_3DSTATE_PIPE_CONTROL | flags | (4 - 2));
OUT_BATCH(0);
OUT_BATCH(0);
OUT_BATCH(0);
ADVANCE_BATCH();
}
}
/**
* Emit a PIPE_CONTROL that writes to a buffer object.
*
* \p flags should contain one of the following items:
* - PIPE_CONTROL_WRITE_IMMEDIATE
* - PIPE_CONTROL_WRITE_TIMESTAMP
* - PIPE_CONTROL_WRITE_DEPTH_COUNT
*/
void
brw_emit_pipe_control_write(struct brw_context *brw, uint32_t flags,
drm_intel_bo *bo, uint32_t offset,
uint32_t imm_lower, uint32_t imm_upper)
{
if (brw->gen >= 8) {
if (brw->gen == 8)
gen8_add_cs_stall_workaround_bits(&flags);
BEGIN_BATCH(6);
OUT_BATCH(_3DSTATE_PIPE_CONTROL | (6 - 2));
OUT_BATCH(flags);
OUT_RELOC64(bo, I915_GEM_DOMAIN_INSTRUCTION, I915_GEM_DOMAIN_INSTRUCTION,
offset);
OUT_BATCH(imm_lower);
OUT_BATCH(imm_upper);
ADVANCE_BATCH();
} else if (brw->gen >= 6) {
flags |= gen7_cs_stall_every_four_pipe_controls(brw, flags);
/* PPGTT/GGTT is selected by DW2 bit 2 on Sandybridge, but DW1 bit 24
* on later platforms. We always use PPGTT on Gen7+.
*/
unsigned gen6_gtt = brw->gen == 6 ? PIPE_CONTROL_GLOBAL_GTT_WRITE : 0;
BEGIN_BATCH(5);
OUT_BATCH(_3DSTATE_PIPE_CONTROL | (5 - 2));
OUT_BATCH(flags);
OUT_RELOC(bo, I915_GEM_DOMAIN_INSTRUCTION, I915_GEM_DOMAIN_INSTRUCTION,
gen6_gtt | offset);
OUT_BATCH(imm_lower);
OUT_BATCH(imm_upper);
ADVANCE_BATCH();
} else {
BEGIN_BATCH(4);
OUT_BATCH(_3DSTATE_PIPE_CONTROL | flags | (4 - 2));
OUT_RELOC(bo, I915_GEM_DOMAIN_INSTRUCTION, I915_GEM_DOMAIN_INSTRUCTION,
PIPE_CONTROL_GLOBAL_GTT_WRITE | offset);
OUT_BATCH(imm_lower);
OUT_BATCH(imm_upper);
ADVANCE_BATCH();
}
}
/**
* Restriction [DevSNB, DevIVB]:
*
* Prior to changing Depth/Stencil Buffer state (i.e. any combination of
* 3DSTATE_DEPTH_BUFFER, 3DSTATE_CLEAR_PARAMS, 3DSTATE_STENCIL_BUFFER,
* 3DSTATE_HIER_DEPTH_BUFFER) SW must first issue a pipelined depth stall
* (PIPE_CONTROL with Depth Stall bit set), followed by a pipelined depth
* cache flush (PIPE_CONTROL with Depth Flush Bit set), followed by
* another pipelined depth stall (PIPE_CONTROL with Depth Stall bit set),
* unless SW can otherwise guarantee that the pipeline from WM onwards is
* already flushed (e.g., via a preceding MI_FLUSH).
*/
void
brw_emit_depth_stall_flushes(struct brw_context *brw)
{
assert(brw->gen >= 6);
/* Starting on BDW, these pipe controls are unnecessary.
*
* WM HW will internally manage the draining pipe and flushing of the caches
* when this command is issued. The PIPE_CONTROL restrictions are removed.
*/
if (brw->gen >= 8)
return;
brw_emit_pipe_control_flush(brw, PIPE_CONTROL_DEPTH_STALL);
brw_emit_pipe_control_flush(brw, PIPE_CONTROL_DEPTH_CACHE_FLUSH);
brw_emit_pipe_control_flush(brw, PIPE_CONTROL_DEPTH_STALL);
}
/**
* From the Ivybridge PRM, Volume 2 Part 1, Section 3.2 (VS Stage Input):
* "A PIPE_CONTROL with Post-Sync Operation set to 1h and a depth
* stall needs to be sent just prior to any 3DSTATE_VS, 3DSTATE_URB_VS,
* 3DSTATE_CONSTANT_VS, 3DSTATE_BINDING_TABLE_POINTER_VS,
* 3DSTATE_SAMPLER_STATE_POINTER_VS command. Only one PIPE_CONTROL needs
* to be sent before any combination of VS associated 3DSTATE."
*/
void
gen7_emit_vs_workaround_flush(struct brw_context *brw)
{
assert(brw->gen == 7);
brw_emit_pipe_control_write(brw,
PIPE_CONTROL_WRITE_IMMEDIATE
| PIPE_CONTROL_DEPTH_STALL,
brw->workaround_bo, 0,
0, 0);
}
/**
* Emit a PIPE_CONTROL command for gen7 with the CS Stall bit set.
*/
void
gen7_emit_cs_stall_flush(struct brw_context *brw)
{
brw_emit_pipe_control_write(brw,
PIPE_CONTROL_CS_STALL
| PIPE_CONTROL_WRITE_IMMEDIATE,
brw->workaround_bo, 0,
0, 0);
}
/**
* Emits a PIPE_CONTROL with a non-zero post-sync operation, for
* implementing two workarounds on gen6. From section 1.4.7.1
* "PIPE_CONTROL" of the Sandy Bridge PRM volume 2 part 1:
*
* [DevSNB-C+{W/A}] Before any depth stall flush (including those
* produced by non-pipelined state commands), software needs to first
* send a PIPE_CONTROL with no bits set except Post-Sync Operation !=
* 0.
*
* [Dev-SNB{W/A}]: Before a PIPE_CONTROL with Write Cache Flush Enable
* =1, a PIPE_CONTROL with any non-zero post-sync-op is required.
*
* And the workaround for these two requires this workaround first:
*
* [Dev-SNB{W/A}]: Pipe-control with CS-stall bit set must be sent
* BEFORE the pipe-control with a post-sync op and no write-cache
* flushes.
*
* And this last workaround is tricky because of the requirements on
* that bit. From section 1.4.7.2.3 "Stall" of the Sandy Bridge PRM
* volume 2 part 1:
*
* "1 of the following must also be set:
* - Render Target Cache Flush Enable ([12] of DW1)
* - Depth Cache Flush Enable ([0] of DW1)
* - Stall at Pixel Scoreboard ([1] of DW1)
* - Depth Stall ([13] of DW1)
* - Post-Sync Operation ([13] of DW1)
* - Notify Enable ([8] of DW1)"
*
* The cache flushes require the workaround flush that triggered this
* one, so we can't use it. Depth stall would trigger the same.
* Post-sync nonzero is what triggered this second workaround, so we
* can't use that one either. Notify enable is IRQs, which aren't
* really our business. That leaves only stall at scoreboard.
*/
void
brw_emit_post_sync_nonzero_flush(struct brw_context *brw)
{
brw_emit_pipe_control_flush(brw,
PIPE_CONTROL_CS_STALL |
PIPE_CONTROL_STALL_AT_SCOREBOARD);
brw_emit_pipe_control_write(brw, PIPE_CONTROL_WRITE_IMMEDIATE,
brw->workaround_bo, 0, 0, 0);
}
/* Emit a pipelined flush to either flush render and texture cache for
* reading from a FBO-drawn texture, or flush so that frontbuffer
* render appears on the screen in DRI1.
*
* This is also used for the always_flush_cache driconf debug option.
*/
void
brw_emit_mi_flush(struct brw_context *brw)
{
if (brw->batch.ring == BLT_RING && brw->gen >= 6) {
BEGIN_BATCH_BLT(4);
OUT_BATCH(MI_FLUSH_DW);
OUT_BATCH(0);
OUT_BATCH(0);
OUT_BATCH(0);
ADVANCE_BATCH();
} else {
int flags = PIPE_CONTROL_NO_WRITE | PIPE_CONTROL_RENDER_TARGET_FLUSH;
if (brw->gen >= 6) {
flags |= PIPE_CONTROL_INSTRUCTION_INVALIDATE |
PIPE_CONTROL_CONST_CACHE_INVALIDATE |
PIPE_CONTROL_DEPTH_CACHE_FLUSH |
PIPE_CONTROL_VF_CACHE_INVALIDATE |
PIPE_CONTROL_TEXTURE_CACHE_INVALIDATE |
PIPE_CONTROL_CS_STALL;
}
brw_emit_pipe_control_flush(brw, flags);
}
}
int
brw_init_pipe_control(struct brw_context *brw,
const struct gen_device_info *devinfo)
{
if (devinfo->gen < 6)
return 0;
/* We can't just use brw_state_batch to get a chunk of space for
* the gen6 workaround because it involves actually writing to
* the buffer, and the kernel doesn't let us write to the batch.
*/
brw->workaround_bo = drm_intel_bo_alloc(brw->bufmgr,
"pipe_control workaround",
4096, 4096);
if (brw->workaround_bo == NULL)
return -ENOMEM;
brw->pipe_controls_since_last_cs_stall = 0;
return 0;
}
void
brw_fini_pipe_control(struct brw_context *brw)
{
drm_intel_bo_unreference(brw->workaround_bo);
}