intel: Delete hardcoded devinfo->urb.size values for Gen7+ (sans DG1).

On all Gen7+ platforms except DG1, the URB is a subsection of the
configurable L3 cache, and so the size can vary.  The size listed
in the documentation on those platforms is an "example size", picked
by calculating it based on an arbitrarily chosen L3 config.

Hardcoding a value for those platforms provides no value and only
confuses people trying to fill out these tables when doing hardware
enabling.  anv and iris never use this field.  i965 uses it to
initialize brw->urb.size, but then updates that in update_urb_size()
to be the correct value, so the initial value doesn't matter.

Delete the values for Gen7+ and update the comment accordingly.

Reviewed-by: Jordan Justen <[email protected]>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4969>

3 files changed, 6 insertions, 35 deletions

diff --git a/src/intel/dev/gen_device_info.c b/src/intel/dev/gen_device_info.c
index 92044501d91..c23a0e9cd19 100644
--- a/src/intel/dev/gen_device_info.c
+++ b/src/intel/dev/gen_device_info.c
@@ -218,7 +218,6 @@ static const struct gen_device_info gen_device_info_ivb_gt1 = {
    .max_wm_threads = 48,
    .max_cs_threads = 36,
    .urb = {
-      .size = 128,
       .min_entries = {
          [MESA_SHADER_VERTEX]    = 32,
          [MESA_SHADER_TESS_EVAL] = 10,
@@ -248,7 +247,6 @@ static const struct gen_device_info gen_device_info_ivb_gt2 = {
    .max_wm_threads = 172,
    .max_cs_threads = 64,
    .urb = {
-      .size = 256,
       .min_entries = {
          [MESA_SHADER_VERTEX]    = 32,
          [MESA_SHADER_TESS_EVAL] = 10,
@@ -278,7 +276,6 @@ static const struct gen_device_info gen_device_info_byt = {
    .max_wm_threads = 48,
    .max_cs_threads = 32,
    .urb = {
-      .size = 128,
       .min_entries = {
          [MESA_SHADER_VERTEX]    = 32,
          [MESA_SHADER_TESS_EVAL] = 10,
@@ -313,7 +310,6 @@ static const struct gen_device_info gen_device_info_hsw_gt1 = {
    .max_wm_threads = 102,
    .max_cs_threads = 70,
    .urb = {
-      .size = 128,
       .min_entries = {
          [MESA_SHADER_VERTEX]    = 32,
          [MESA_SHADER_TESS_EVAL] = 10,
@@ -342,7 +338,6 @@ static const struct gen_device_info gen_device_info_hsw_gt2 = {
    .max_wm_threads = 204,
    .max_cs_threads = 70,
    .urb = {
-      .size = 256,
       .min_entries = {
          [MESA_SHADER_VERTEX]    = 64,
          [MESA_SHADER_TESS_EVAL] = 10,
@@ -371,7 +366,6 @@ static const struct gen_device_info gen_device_info_hsw_gt3 = {
    .max_wm_threads = 408,
    .max_cs_threads = 70,
    .urb = {
-      .size = 512,
       .min_entries = {
          [MESA_SHADER_VERTEX]    = 64,
          [MESA_SHADER_TESS_EVAL] = 10,
@@ -419,7 +413,6 @@ static const struct gen_device_info gen_device_info_bdw_gt1 = {
    .l3_banks = 2,
    .max_cs_threads = 42,
    .urb = {
-      .size = 192,
       .min_entries = {
          [MESA_SHADER_VERTEX]    = 64,
          [MESA_SHADER_TESS_EVAL] = 34,
@@ -444,7 +437,6 @@ static const struct gen_device_info gen_device_info_bdw_gt2 = {
    .l3_banks = 4,
    .max_cs_threads = 56,
    .urb = {
-      .size = 384,
       .min_entries = {
          [MESA_SHADER_VERTEX]    = 64,
          [MESA_SHADER_TESS_EVAL] = 34,
@@ -468,7 +460,6 @@ static const struct gen_device_info gen_device_info_bdw_gt3 = {
    .l3_banks = 8,
    .max_cs_threads = 56,
    .urb = {
-      .size = 384,
       .min_entries = {
          [MESA_SHADER_VERTEX]    = 64,
          [MESA_SHADER_TESS_EVAL] = 34,
@@ -498,7 +489,6 @@ static const struct gen_device_info gen_device_info_chv = {
    .max_wm_threads = 128,
    .max_cs_threads = 6 * 7,
    .urb = {
-      .size = 192,
       .min_entries = {
          [MESA_SHADER_VERTEX]    = 34,
          [MESA_SHADER_TESS_EVAL] = 34,
@@ -522,7 +512,6 @@ static const struct gen_device_info gen_device_info_chv = {
    .max_cs_threads = 56,                            \
    .timestamp_frequency = 12000000,                 \
    .urb = {                                         \
-      .size = 384,                                  \
       .min_entries = {                              \
          [MESA_SHADER_VERTEX]    = 64,              \
          [MESA_SHADER_TESS_EVAL] = 34,              \
@@ -551,7 +540,6 @@ static const struct gen_device_info gen_device_info_chv = {
    .max_cs_threads = 6 * 6,                        \
    .timestamp_frequency = 19200000,                \
    .urb = {                                        \
-      .size = 192,                                 \
       .min_entries = {                             \
          [MESA_SHADER_VERTEX]    = 34,             \
          [MESA_SHADER_TESS_EVAL] = 34,             \
@@ -579,7 +567,6 @@ static const struct gen_device_info gen_device_info_chv = {
    .max_gs_threads = 56,                           \
    .max_cs_threads = 6 * 6,                        \
    .urb = {                                        \
-      .size = 128,                                 \
       .min_entries = {                             \
          [MESA_SHADER_VERTEX]    = 34,             \
          [MESA_SHADER_TESS_EVAL] = 34,             \
@@ -604,7 +591,6 @@ static const struct gen_device_info gen_device_info_skl_gt1 = {
    .num_subslices = { 2, },
    .num_eu_per_subslice = 6,
    .l3_banks = 2,
-   .urb.size = 192,
    /* GT1 seems to have a bug in the top of the pipe (VF/VS?) fixed functions
     * leading to some vertices to go missing if we use too much URB.
     */
@@ -647,7 +633,6 @@ static const struct gen_device_info gen_device_info_skl_gt4 = {
     * allocation of the L3 data array to provide 3*384KB=1152KB for URB, but
     * only 1008KB of this will be used."
     */
-   .urb.size = 1008 / 3,
    .simulator_id = 12,
 };
 
@@ -675,7 +660,6 @@ static const struct gen_device_info gen_device_info_kbl_gt1 = {
    .gt = 1,
 
    .max_cs_threads = 7 * 6,
-   .urb.size = 192,
    .num_slices = 1,
    .num_subslices = { 2, },
    .num_eu_per_subslice = 6,
@@ -739,7 +723,6 @@ static const struct gen_device_info gen_device_info_kbl_gt4 = {
     *  provide 3*384KB=1152KB for URB, but only 1008KB of this
     *  will be used."
     */
-   .urb.size = 1008 / 3,
    .num_slices = 3,
    .num_subslices = { 3, 3, 3, },
    .num_eu_per_subslice = 8,
@@ -770,7 +753,6 @@ static const struct gen_device_info gen_device_info_cfl_gt1 = {
    .num_subslices = { 2, },
    .num_eu_per_subslice = 6,
    .l3_banks = 2,
-   .urb.size = 192,
    /* GT1 seems to have a bug in the top of the pipe (VF/VS?) fixed functions
     * leading to some vertices to go missing if we use too much URB.
     */
@@ -811,7 +793,6 @@ static const struct gen_device_info gen_device_info_cfl_gt3 = {
    .max_cs_threads = 56,                            \
    .timestamp_frequency = 19200000,                 \
    .urb = {                                         \
-      .size = 256,                                  \
       .min_entries = {                              \
          [MESA_SHADER_VERTEX]    = 64,              \
          [MESA_SHADER_TESS_EVAL] = 34,              \
@@ -899,7 +880,6 @@ static const struct gen_device_info gen_device_info_cnl_gt2 = {
 static const struct gen_device_info gen_device_info_icl_gt2 = {
    GEN11_FEATURES(2, 1, subslices(8), 8),
    .urb = {
-      .size = 1024,
       GEN11_URB_MIN_MAX_ENTRIES,
    },
    .simulator_id = 19,
@@ -908,7 +888,6 @@ static const struct gen_device_info gen_device_info_icl_gt2 = {
 static const struct gen_device_info gen_device_info_icl_gt1_5 = {
    GEN11_FEATURES(1, 1, subslices(6), 6),
    .urb = {
-      .size = 768,
       GEN11_URB_MIN_MAX_ENTRIES,
    },
    .simulator_id = 19,
@@ -917,7 +896,6 @@ static const struct gen_device_info gen_device_info_icl_gt1_5 = {
 static const struct gen_device_info gen_device_info_icl_gt1 = {
    GEN11_FEATURES(1, 1, subslices(4), 6),
    .urb = {
-      .size = 768,
       GEN11_URB_MIN_MAX_ENTRIES,
    },
    .simulator_id = 19,
@@ -926,7 +904,6 @@ static const struct gen_device_info gen_device_info_icl_gt1 = {
 static const struct gen_device_info gen_device_info_icl_gt0_5 = {
    GEN11_FEATURES(1, 1, subslices(1), 6),
    .urb = {
-      .size = 768,
       GEN11_URB_MIN_MAX_ENTRIES,
    },
    .simulator_id = 19,
@@ -936,7 +913,6 @@ static const struct gen_device_info gen_device_info_ehl_7 = {
    GEN11_FEATURES(1, 1, subslices(4), 4),
    .is_elkhartlake = true,
    .urb = {
-      .size = 512,
       .min_entries = {
          [MESA_SHADER_VERTEX]    = 64,
          [MESA_SHADER_TESS_EVAL] = 34,
@@ -956,7 +932,6 @@ static const struct gen_device_info gen_device_info_ehl_6 = {
    GEN11_FEATURES(1, 1, subslices(4), 4),
    .is_elkhartlake = true,
    .urb = {
-      .size = 512,
       .min_entries = {
          [MESA_SHADER_VERTEX]    = 64,
          [MESA_SHADER_TESS_EVAL] = 34,
@@ -977,7 +952,6 @@ static const struct gen_device_info gen_device_info_ehl_5 = {
    GEN11_FEATURES(1, 1, subslices(4), 4),
    .is_elkhartlake = true,
    .urb = {
-      .size = 512,
       .min_entries = {
          [MESA_SHADER_VERTEX]    = 64,
          [MESA_SHADER_TESS_EVAL] = 34,
@@ -998,7 +972,6 @@ static const struct gen_device_info gen_device_info_ehl_4 = {
    GEN11_FEATURES(1, 1, subslices(2), 4),
    .is_elkhartlake = true,
    .urb = {
-      .size = 512,
       .min_entries = {
          [MESA_SHADER_VERTEX]    = 64,
          [MESA_SHADER_TESS_EVAL] = 34,
@@ -1049,7 +1022,6 @@ static const struct gen_device_info gen_device_info_ehl_4 = {
    .has_integer_dword_mul = false,                              \
    .gt = _gt, .num_slices = _slices, .l3_banks = _l3,           \
    .simulator_id = 22,                                          \
-   .urb.size = (_gt) == 1 ? 512 : 1024,                         \
    .num_eu_per_subslice = 16
 
 #define dual_subslices(args...) { args, }
diff --git a/src/intel/dev/gen_device_info.h b/src/intel/dev/gen_device_info.h
index 73538160b54..d465d5ffd2e 100644
--- a/src/intel/dev/gen_device_info.h
+++ b/src/intel/dev/gen_device_info.h
@@ -207,14 +207,14 @@ struct gen_device_info
 
    struct {
       /**
-       * Hardware default URB size.
+       * Fixed size of the URB.
        *
-       * The units this is expressed in are somewhat inconsistent: 512b units
-       * on Gen4-5, KB on Gen6-7, and KB times the slice count on Gen8+.
+       * On Gen6 and DG1, this is measured in KB.  Gen4-5 instead measure
+       * this in 512b blocks, as that's more convenient there.
        *
-       * Look up "URB Size" in the "Device Attributes" page, and take the
-       * maximum.  Look up the slice count for each GT SKU on the same page.
-       * urb.size = URB Size (kbytes) / slice count
+       * On most Gen7+ platforms, the URB is a section of the L3 cache,
+       * and can be resized based on the L3 programming.  For those platforms,
+       * simply leave this field blank (zero) - it isn't used.
        */
       unsigned size;
 
diff --git a/src/intel/dev/gen_device_info_test.c b/src/intel/dev/gen_device_info_test.c
index a47d8155861..f104163db69 100644
--- a/src/intel/dev/gen_device_info_test.c
+++ b/src/intel/dev/gen_device_info_test.c
@@ -24,7 +24,6 @@ main(int argc, char *argv[])
       assert(gen_get_device_info_from_pci_id(chipsets[i].pci_id, &devinfo));
 
       assert(devinfo.gen != 0);
-      assert(devinfo.urb.size != 0);
       assert(devinfo.num_eu_per_subslice != 0);
       assert(devinfo.num_thread_per_eu != 0);
       assert(devinfo.timestamp_frequency != 0);