src/mesa/drivers/dri/i965/gen7_urb.c

   1 /*
   2  * Copyright © 2011 Intel Corporation
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the next
  12  * paragraph) shall be included in all copies or substantial portions of the
  13  * Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  21  * IN THE SOFTWARE.
  22  */
  23
  24 #include "main/macros.h"
  25 #include "intel_batchbuffer.h"
  26 #include "brw_context.h"
  27 #include "brw_state.h"
  28 #include "brw_defines.h"
  29
  30 /**
  31  * The following diagram shows how we partition the URB:
  32  *
  33  *      8kB         8kB              Rest of the URB space
  34  *   ____-____   ____-____   _________________-_________________
  35  *  /         \ /         \ /                                   \
  36  * +-------------------------------------------------------------+
  37  * | VS Push   | FS Push   | VS                                  |
  38  * | Constants | Constants | Handles                             |
  39  * +-------------------------------------------------------------+
  40  *
  41  * Notably, push constants must be stored at the beginning of the URB
  42  * space, while entries can be stored anywhere.  Ivybridge has a maximum
  43  * constant buffer size of 16kB.
  44  *
  45  * Currently we split the constant buffer space evenly between VS and FS.
  46  * This is probably not ideal, but simple.
  47  *
  48  * Ivybridge GT1 has 128kB of URB space.
  49  * Ivybridge GT2 has 256kB of URB space.
  50  *
  51  * See "Volume 2a: 3D Pipeline," section 1.8.
  52  */
  53 static void
  54 prepare_urb(struct brw_context *brw)
  55 {
  56    /* Total space for entries is URB size - 16kB for push constants */
  57    int handle_region_size = (brw->urb.size - 16) * 1024; /* bytes */
  58
  59    /* CACHE_NEW_VS_PROG */
  60    brw->urb.vs_size = MAX2(brw->vs.prog_data->urb_entry_size, 1);
  61
  62    int nr_vs_entries = handle_region_size / (brw->urb.vs_size * 64);
  63    if (nr_vs_entries > brw->urb.max_vs_entries)
  64       nr_vs_entries = brw->urb.max_vs_entries;
  65
  66    /* According to volume 2a, nr_vs_entries must be a multiple of 8. */
  67    brw->urb.nr_vs_entries = ROUND_DOWN_TO(nr_vs_entries, 8);
  68
  69    /* URB Starting Addresses are specified in multiples of 8kB. */
  70    brw->urb.vs_start = 2; /* skip over push constants */
  71 }
  72
  73 static void
  74 upload_urb(struct brw_context *brw)
  75 {
  76    struct intel_context *intel = &brw->intel;
  77
  78    assert(brw->urb.nr_vs_entries % 8 == 0);
  79    assert(brw->urb.nr_gs_entries % 8 == 0);
  80    /* GS requirement */
  81    assert(brw->gs.prog_active);
  82
  83    BEGIN_BATCH(2);
  84    OUT_BATCH(_3DSTATE_PUSH_CONSTANT_ALLOC_VS << 16 | (2 - 2));
  85    OUT_BATCH(8);
  86    ADVANCE_BATCH();
  87
  88    BEGIN_BATCH(2);
  89    OUT_BATCH(_3DSTATE_PUSH_CONSTANT_ALLOC_PS << 16 | (2 - 2));
  90    OUT_BATCH(8 | 8 << GEN7_PUSH_CONSTANT_BUFFER_OFFSET_SHIFT);
  91    ADVANCE_BATCH();
  92
  93    BEGIN_BATCH(2);
  94    OUT_BATCH(_3DSTATE_URB_VS << 16 | (2 - 2));
  95    OUT_BATCH(brw->urb.nr_vs_entries |
  96              ((brw->urb.vs_size - 1) << GEN7_URB_ENTRY_SIZE_SHIFT) |
  97              (brw->urb.vs_start << GEN7_URB_STARTING_ADDRESS_SHIFT));
  98    ADVANCE_BATCH();
  99
 100    /* Allocate the GS, HS, and DS zero space - we don't use them. */
 101    BEGIN_BATCH(2);
 102    OUT_BATCH(_3DSTATE_URB_GS << 16 | (2 - 2));
 103    OUT_BATCH((0 << GEN7_URB_ENTRY_SIZE_SHIFT) |
 104              (2 << GEN7_URB_STARTING_ADDRESS_SHIFT));
 105    ADVANCE_BATCH();
 106
 107    BEGIN_BATCH(2);
 108    OUT_BATCH(_3DSTATE_URB_HS << 16 | (2 - 2));
 109    OUT_BATCH((0 << GEN7_URB_ENTRY_SIZE_SHIFT) |
 110              (2 << GEN7_URB_STARTING_ADDRESS_SHIFT));
 111    ADVANCE_BATCH();
 112
 113    BEGIN_BATCH(2);
 114    OUT_BATCH(_3DSTATE_URB_DS << 16 | (2 - 2));
 115    OUT_BATCH((0 << GEN7_URB_ENTRY_SIZE_SHIFT) |
 116              (2 << GEN7_URB_STARTING_ADDRESS_SHIFT));
 117    ADVANCE_BATCH();
 118 }
 119
 120 const struct brw_tracked_state gen7_urb = {
 121    .dirty = {
 122       .mesa = 0,
 123       .brw = BRW_NEW_CONTEXT,
 124       .cache = (CACHE_NEW_VS_PROG | CACHE_NEW_GS_PROG),
 125    },
 126    .prepare = prepare_urb,
 127    .emit = upload_urb,
 128 };