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/*
* Copyright © 2009 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>
*
*/
#include "main/macros.h"
#include "intel_batchbuffer.h"
#include "brw_context.h"
#include "brw_state.h"
#include "brw_defines.h"
/**
* When the GS is not in use, we assign the entire URB space to the VS. When
* the GS is in use, we split the URB space evenly between the VS and the GS.
* This is not ideal, but it's simple.
*
* URB size / 2 URB size / 2
* _____________-______________ _____________-______________
* / \ / \
* +-------------------------------------------------------------+
* | Vertex Shader Entries | Geometry Shader Entries |
* +-------------------------------------------------------------+
*
* Sandybridge GT1 has 32kB of URB space, while GT2 has 64kB.
* (See the Sandybridge PRM, Volume 2, Part 1, Section 1.4.7: 3DSTATE_URB.)
*/
static void
gen6_upload_urb( struct brw_context *brw )
{
int nr_vs_entries, nr_gs_entries;
int total_urb_size = brw->urb.size * 1024; /* in bytes */
bool gs_present = brw->ff_gs.prog_active || brw->geometry_program;
/* BRW_NEW_VS_PROG_DATA */
unsigned vs_size = MAX2(brw->vs.prog_data->base.urb_entry_size, 1);
/* Whe using GS to do transform feedback only we use the same VUE layout for
* VS outputs and GS outputs (as it's what the SF and Clipper expect), so we
* can simply make the GS URB entry size the same as for the VS. This may
* technically be too large in cases where we have few vertex attributes and
* a lot of varyings, since the VS size is determined by the larger of the
* two. For now, it's safe.
*
* For user-provided GS the assumption above does not hold since the GS
* outputs can be different from the VS outputs.
*/
unsigned gs_size = vs_size;
if (brw->geometry_program) {
gs_size = brw->gs.prog_data->base.urb_entry_size;
assert(gs_size >= 1);
}
/* Calculate how many entries fit in each stage's section of the URB */
if (gs_present) {
nr_vs_entries = (total_urb_size/2) / (vs_size * 128);
nr_gs_entries = (total_urb_size/2) / (gs_size * 128);
} else {
nr_vs_entries = total_urb_size / (vs_size * 128);
nr_gs_entries = 0;
}
/* Then clamp to the maximum allowed by the hardware */
if (nr_vs_entries > brw->urb.max_vs_entries)
nr_vs_entries = brw->urb.max_vs_entries;
if (nr_gs_entries > brw->urb.max_gs_entries)
nr_gs_entries = brw->urb.max_gs_entries;
/* Finally, both must be a multiple of 4 (see 3DSTATE_URB in the PRM). */
brw->urb.nr_vs_entries = ROUND_DOWN_TO(nr_vs_entries, 4);
brw->urb.nr_gs_entries = ROUND_DOWN_TO(nr_gs_entries, 4);
assert(brw->urb.nr_vs_entries >= brw->urb.min_vs_entries);
assert(brw->urb.nr_vs_entries % 4 == 0);
assert(brw->urb.nr_gs_entries % 4 == 0);
assert(vs_size <= 5);
assert(gs_size <= 5);
BEGIN_BATCH(3);
OUT_BATCH(_3DSTATE_URB << 16 | (3 - 2));
OUT_BATCH(((vs_size - 1) << GEN6_URB_VS_SIZE_SHIFT) |
((brw->urb.nr_vs_entries) << GEN6_URB_VS_ENTRIES_SHIFT));
OUT_BATCH(((gs_size - 1) << GEN6_URB_GS_SIZE_SHIFT) |
((brw->urb.nr_gs_entries) << GEN6_URB_GS_ENTRIES_SHIFT));
ADVANCE_BATCH();
/* From the PRM Volume 2 part 1, section 1.4.7:
*
* Because of a urb corruption caused by allocating a previous gsunit’s
* urb entry to vsunit software is required to send a "GS NULL
* Fence"(Send URB fence with VS URB size == 1 and GS URB size == 0) plus
* a dummy DRAW call before any case where VS will be taking over GS URB
* space.
*
* It is not clear exactly what this means ("URB fence" is a command that
* doesn't exist on Gen6). So for now we just do a full pipeline flush as
* a workaround.
*/
if (brw->urb.gs_present && !gs_present)
brw_emit_mi_flush(brw);
brw->urb.gs_present = gs_present;
}
const struct brw_tracked_state gen6_urb = {
.dirty = {
.mesa = 0,
.brw = BRW_NEW_CONTEXT |
BRW_NEW_FF_GS_PROG_DATA |
BRW_NEW_GEOMETRY_PROGRAM |
BRW_NEW_GS_PROG_DATA |
BRW_NEW_VS_PROG_DATA,
},
.emit = gen6_upload_urb,
};
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