[Mesa-dev] [PATCH 6/7] i965: Use arrays in Gen7+ URB code.

Pohjolainen, Topi topi.pohjolainen at gmail.com
Wed Nov 16 10:25:30 UTC 2016


On Tue, Nov 15, 2016 at 05:54:01PM -0800, Kenneth Graunke wrote:
> So much of this code was cut and pasted per stage.  We can accomplish
> much of it by looping over shader stages.

I laid out original and new side-by-side and tried to compare things
carefully. To me everything looks to match. Thanks for doing this, better!

Reviewed-by: Topi Pohjolainen <topi.pohjolainen at intel.com>

(I had a few const nits in mind but I'll note them in next patch).

> 
> Signed-off-by: Kenneth Graunke <kenneth at whitecape.org>
> ---
>  src/mesa/drivers/dri/i965/gen7_urb.c | 336 ++++++++++++++---------------------
>  1 file changed, 134 insertions(+), 202 deletions(-)
> 
> diff --git a/src/mesa/drivers/dri/i965/gen7_urb.c b/src/mesa/drivers/dri/i965/gen7_urb.c
> index 61fd774..72b409c 100644
> --- a/src/mesa/drivers/dri/i965/gen7_urb.c
> +++ b/src/mesa/drivers/dri/i965/gen7_urb.c
> @@ -152,40 +152,6 @@ const struct brw_tracked_state gen7_push_constant_space = {
>  };
>  
>  static void
> -gen7_emit_urb_state(struct brw_context *brw,
> -                    unsigned nr_vs_entries,
> -                    unsigned vs_size, unsigned vs_start,
> -                    unsigned nr_hs_entries,
> -                    unsigned hs_size, unsigned hs_start,
> -                    unsigned nr_ds_entries,
> -                    unsigned ds_size, unsigned ds_start,
> -                    unsigned nr_gs_entries,
> -                    unsigned gs_size, unsigned gs_start)
> -{
> -   BEGIN_BATCH(8);
> -   OUT_BATCH(_3DSTATE_URB_VS << 16 | (2 - 2));
> -   OUT_BATCH(nr_vs_entries |
> -             ((vs_size - 1) << GEN7_URB_ENTRY_SIZE_SHIFT) |
> -             (vs_start << GEN7_URB_STARTING_ADDRESS_SHIFT));
> -
> -   OUT_BATCH(_3DSTATE_URB_GS << 16 | (2 - 2));
> -   OUT_BATCH(nr_gs_entries |
> -             ((gs_size - 1) << GEN7_URB_ENTRY_SIZE_SHIFT) |
> -             (gs_start << GEN7_URB_STARTING_ADDRESS_SHIFT));
> -
> -   OUT_BATCH(_3DSTATE_URB_HS << 16 | (2 - 2));
> -   OUT_BATCH(nr_hs_entries |
> -             ((hs_size - 1) << GEN7_URB_ENTRY_SIZE_SHIFT) |
> -             (hs_start << GEN7_URB_STARTING_ADDRESS_SHIFT));
> -
> -   OUT_BATCH(_3DSTATE_URB_DS << 16 | (2 - 2));
> -   OUT_BATCH(nr_ds_entries |
> -             ((ds_size - 1) << GEN7_URB_ENTRY_SIZE_SHIFT) |
> -             (ds_start << GEN7_URB_STARTING_ADDRESS_SHIFT));
> -   ADVANCE_BATCH();
> -}
> -
> -static void
>  upload_urb(struct brw_context *brw)
>  {
>     /* BRW_NEW_VS_PROG_DATA */
> @@ -208,56 +174,45 @@ gen7_upload_urb(struct brw_context *brw, unsigned vs_size,
>     const int push_size_kB =
>        (brw->gen >= 8 || (brw->is_haswell && brw->gt == 3)) ? 32 : 16;
>  
> -   /* BRW_NEW_VS_PROG_DATA */
> -   unsigned vs_entry_size_bytes = vs_size * 64;
> -   /* BRW_NEW_GEOMETRY_PROGRAM, BRW_NEW_GS_PROG_DATA */
> -   const struct brw_vue_prog_data *gs_vue_prog_data =
> -      brw_vue_prog_data(brw->gs.base.prog_data);
> -   unsigned gs_size = gs_present ? gs_vue_prog_data->urb_entry_size : 1;
> -   unsigned gs_entry_size_bytes = gs_size * 64;
> -
> -   /* BRW_NEW_TCS_PROG_DATA */
> -   const struct brw_vue_prog_data *tcs_vue_prog_data =
> -      brw_vue_prog_data(brw->tcs.base.prog_data);
> -   unsigned hs_size = tess_present ? tcs_vue_prog_data->urb_entry_size : 1;
> -   unsigned hs_entry_size_bytes = hs_size * 64;
> -   /* BRW_NEW_TES_PROG_DATA */
> -   const struct brw_vue_prog_data *tes_vue_prog_data =
> -      brw_vue_prog_data(brw->tes.base.prog_data);
> -   unsigned ds_size = tess_present ? tes_vue_prog_data->urb_entry_size : 1;
> -   unsigned ds_entry_size_bytes = ds_size * 64;
> +   const bool active[4] = { true, tess_present, tess_present, gs_present };
> +
> +   /* BRW_NEW_{VS,TCS,TES,GS}_PROG_DATA */
> +   struct brw_vue_prog_data *prog_data[4] = {
> +      [MESA_SHADER_VERTEX] =
> +         brw_vue_prog_data(brw->vs.base.prog_data),
> +      [MESA_SHADER_TESS_CTRL] =
> +         tess_present ? brw_vue_prog_data(brw->tcs.base.prog_data) : NULL,
> +      [MESA_SHADER_TESS_EVAL] =
> +         tess_present ? brw_vue_prog_data(brw->tes.base.prog_data) : NULL,
> +      [MESA_SHADER_GEOMETRY] =
> +         gs_present ? brw_vue_prog_data(brw->gs.base.prog_data) : NULL,
> +   };
> +
> +   unsigned entry_size[4];
> +   entry_size[MESA_SHADER_VERTEX] = vs_size;
> +   for (int i = MESA_SHADER_TESS_CTRL; i <= MESA_SHADER_GEOMETRY; i++) {
> +      entry_size[i] = prog_data[i] ? prog_data[i]->urb_entry_size : 1;
> +   }
>  
>     /* If we're just switching between programs with the same URB requirements,
>      * skip the rest of the logic.
>      */
>     if (!(brw->ctx.NewDriverState & BRW_NEW_CONTEXT) &&
>         !(brw->ctx.NewDriverState & BRW_NEW_URB_SIZE) &&
> -       brw->urb.vsize == vs_size &&
> +       brw->urb.vsize == entry_size[MESA_SHADER_VERTEX] &&
>         brw->urb.gs_present == gs_present &&
> -       brw->urb.gsize == gs_size &&
> +       brw->urb.gsize == entry_size[MESA_SHADER_GEOMETRY] &&
>         brw->urb.tess_present == tess_present &&
> -       brw->urb.hsize == hs_size &&
> -       brw->urb.dsize == ds_size) {
> +       brw->urb.hsize == entry_size[MESA_SHADER_TESS_CTRL] &&
> +       brw->urb.dsize == entry_size[MESA_SHADER_TESS_EVAL]) {
>        return;
>     }
> -   brw->urb.vsize = vs_size;
> +   brw->urb.vsize = entry_size[MESA_SHADER_VERTEX];
>     brw->urb.gs_present = gs_present;
> -   brw->urb.gsize = gs_size;
> +   brw->urb.gsize = entry_size[MESA_SHADER_GEOMETRY];
>     brw->urb.tess_present = tess_present;
> -   brw->urb.hsize = hs_size;
> -   brw->urb.dsize = ds_size;
> -
> -   /* From p35 of the Ivy Bridge PRM (section 1.7.1: 3DSTATE_URB_GS):
> -    *
> -    *     VS Number of URB Entries must be divisible by 8 if the VS URB Entry
> -    *     Allocation Size is less than 9 512-bit URB entries.
> -    *
> -    * Similar text exists for HS, DS and GS.
> -    */
> -   unsigned vs_granularity = (vs_size < 9) ? 8 : 1;
> -   unsigned hs_granularity = (hs_size < 9) ? 8 : 1;
> -   unsigned ds_granularity = (ds_size < 9) ? 8 : 1;
> -   unsigned gs_granularity = (gs_size < 9) ? 8 : 1;
> +   brw->urb.hsize = entry_size[MESA_SHADER_TESS_CTRL];
> +   brw->urb.dsize = entry_size[MESA_SHADER_TESS_EVAL];
>  
>     /* URB allocations must be done in 8k chunks. */
>     unsigned chunk_size_bytes = 8192;
> @@ -269,36 +224,30 @@ gen7_upload_urb(struct brw_context *brw, unsigned vs_size,
>  
>     /* Reserve space for push constants */
>     unsigned push_constant_bytes = 1024 * push_size_kB;
> -   unsigned push_constant_chunks =
> -      push_constant_bytes / chunk_size_bytes;
> -
> -   /* Initially, assign each stage the minimum amount of URB space it needs,
> -    * and make a note of how much additional space it "wants" (the amount of
> -    * additional space it could actually make use of).
> -    */
> +   unsigned push_constant_chunks = push_constant_bytes / chunk_size_bytes;
>  
> -   /* VS has a lower limit on the number of URB entries.
> +   /* From p35 of the Ivy Bridge PRM (section 1.7.1: 3DSTATE_URB_GS):
>      *
> -    * From the Broadwell PRM, 3DSTATE_URB_VS instruction:
> -    * "When tessellation is enabled, the VS Number of URB Entries must be
> -    *  greater than or equal to 192."
> +    *     VS Number of URB Entries must be divisible by 8 if the VS URB Entry
> +    *     Allocation Size is less than 9 512-bit URB entries.
> +    *
> +    * Similar text exists for HS, DS and GS.
>      */
> -   unsigned vs_min_entries =
> -      tess_present && brw->gen == 8 ?
> -         192 : devinfo->urb.min_entries[MESA_SHADER_VERTEX];
> -   /* Min VS Entries isn't a multiple of 8 on Cherryview/Broxton; round up */
> -   vs_min_entries = ALIGN(vs_min_entries, vs_granularity);
> -
> -   unsigned vs_chunks =
> -      DIV_ROUND_UP(vs_min_entries * vs_entry_size_bytes, chunk_size_bytes);
> -   unsigned vs_wants =
> -      DIV_ROUND_UP(devinfo->urb.max_entries[MESA_SHADER_VERTEX] *
> -                   vs_entry_size_bytes,
> -                   chunk_size_bytes) - vs_chunks;
> -
> -   unsigned gs_chunks = 0;
> -   unsigned gs_wants = 0;
> -   if (gs_present) {
> +   unsigned granularity[4];
> +   for (int i = MESA_SHADER_VERTEX; i <= MESA_SHADER_GEOMETRY; i++) {
> +      granularity[i] = (entry_size[i] < 9) ? 8 : 1;
> +   }
> +
> +   unsigned min_entries[4] = {
> +      /* VS has a lower limit on the number of URB entries.
> +       *
> +       * From the Broadwell PRM, 3DSTATE_URB_VS instruction:
> +       * "When tessellation is enabled, the VS Number of URB Entries must be
> +       *  greater than or equal to 192."
> +       */
> +      [MESA_SHADER_VERTEX] = tess_present && brw->gen == 8 ?
> +         192 : devinfo->urb.min_entries[MESA_SHADER_VERTEX],
> +
>        /* There are two constraints on the minimum amount of URB space we can
>         * allocate:
>         *
> @@ -307,133 +256,116 @@ gen7_upload_urb(struct brw_context *brw, unsigned vs_size,
>         *
>         * (2) We can't allocate less than nr_gs_entries_granularity.
>         */
> -      gs_chunks = DIV_ROUND_UP(MAX2(gs_granularity, 2) * gs_entry_size_bytes,
> -                               chunk_size_bytes);
> -      gs_wants = DIV_ROUND_UP(devinfo->urb.max_entries[MESA_SHADER_GEOMETRY] *
> -                              gs_entry_size_bytes,
> -                              chunk_size_bytes) - gs_chunks;
> +      [MESA_SHADER_GEOMETRY] = gs_present ? 2 : 0,
> +
> +      [MESA_SHADER_TESS_CTRL] = tess_present ? 1 : 0,
> +
> +      [MESA_SHADER_TESS_EVAL] = tess_present ?
> +         devinfo->urb.min_entries[MESA_SHADER_TESS_EVAL] : 0,
> +   };
> +
> +   /* Min VS Entries isn't a multiple of 8 on Cherryview/Broxton; round up.
> +    * Round them all up.
> +    */
> +   for (int i = MESA_SHADER_VERTEX; i <= MESA_SHADER_GEOMETRY; i++) {
> +      min_entries[i] = ALIGN(min_entries[i], granularity[i]);
>     }
>  
> -   unsigned hs_chunks = 0;
> -   unsigned hs_wants = 0;
> -   unsigned ds_chunks = 0;
> -   unsigned ds_wants = 0;
> -
> -   if (tess_present) {
> -      hs_chunks =
> -         DIV_ROUND_UP(hs_granularity * hs_entry_size_bytes,
> -                      chunk_size_bytes);
> -      hs_wants =
> -         DIV_ROUND_UP(devinfo->urb.max_entries[MESA_SHADER_TESS_CTRL] *
> -                      hs_entry_size_bytes, chunk_size_bytes) - hs_chunks;
> -
> -      ds_chunks =
> -         DIV_ROUND_UP(devinfo->urb.min_entries[MESA_SHADER_TESS_EVAL] *
> -                      ds_entry_size_bytes, chunk_size_bytes);
> -      ds_wants =
> -         DIV_ROUND_UP(devinfo->urb.max_entries[MESA_SHADER_TESS_EVAL] *
> -                      ds_entry_size_bytes, chunk_size_bytes) - ds_chunks;
> +   unsigned entry_size_bytes[4];
> +   for (int i = MESA_SHADER_VERTEX; i <= MESA_SHADER_GEOMETRY; i++) {
> +      entry_size_bytes[i] = 64 * entry_size[i];
>     }
>  
> -   /* There should always be enough URB space to satisfy the minimum
> -    * requirements of each stage.
> +   /* Initially, assign each stage the minimum amount of URB space it needs,
> +    * and make a note of how much additional space it "wants" (the amount of
> +    * additional space it could actually make use of).
>      */
> -   unsigned total_needs = push_constant_chunks +
> -                          vs_chunks + hs_chunks + ds_chunks + gs_chunks;
> +   unsigned chunks[4];
> +   unsigned wants[4];
> +   unsigned total_needs = push_constant_chunks;
> +   unsigned total_wants = 0;
> +
> +   for (int i = MESA_SHADER_VERTEX; i <= MESA_SHADER_GEOMETRY; i++) {
> +      if (active[i]) {
> +         chunks[i] = DIV_ROUND_UP(min_entries[i] * entry_size_bytes[i],
> +                                  chunk_size_bytes);
> +
> +         wants[i] =
> +            DIV_ROUND_UP(devinfo->urb.max_entries[i] * entry_size_bytes[i],
> +                         chunk_size_bytes) - chunks[i];
> +      } else {
> +         chunks[i] = 0;
> +         wants[i] = 0;
> +      }
> +
> +      total_needs += chunks[i];
> +      total_wants += wants[i];
> +   }
> +
>     assert(total_needs <= urb_chunks);
>  
>     /* Mete out remaining space (if any) in proportion to "wants". */
> -   unsigned total_wants = vs_wants + hs_wants + ds_wants + gs_wants;
> -   unsigned remaining_space = urb_chunks - total_needs;
> -   if (remaining_space > total_wants)
> -      remaining_space = total_wants;
> -   if (remaining_space > 0) {
> -      unsigned vs_additional = (unsigned)
> -         roundf(vs_wants * (((float) remaining_space) / total_wants));
> -      vs_chunks += vs_additional;
> -      remaining_space -= vs_additional;
> -      total_wants -= vs_wants;
> -
> -      if (total_wants > 0) {
> -         unsigned hs_additional = (unsigned)
> -            roundf(hs_wants * (((float) remaining_space) / total_wants));
> -         hs_chunks += hs_additional;
> -         remaining_space -= hs_additional;
> -         total_wants -= hs_wants;
> -      }
> +   unsigned remaining_space = MIN2(urb_chunks - total_needs, total_wants);
>  
> -      if (total_wants > 0) {
> -         unsigned ds_additional = (unsigned)
> -            roundf(ds_wants * (((float) remaining_space) / total_wants));
> -         ds_chunks += ds_additional;
> -         remaining_space -= ds_additional;
> -         total_wants -= ds_wants;
> +   if (remaining_space > 0) {
> +      for (int i = MESA_SHADER_VERTEX;
> +           total_wants > 0 && i <= MESA_SHADER_TESS_EVAL; i++) {
> +         unsigned additional = (unsigned)
> +            roundf(wants[i] * (((float) remaining_space) / total_wants));
> +         chunks[i] += additional;
> +         remaining_space -= additional;
> +         total_wants -= additional;
>        }
>  
> -      gs_chunks += remaining_space;
> +      chunks[MESA_SHADER_GEOMETRY] += remaining_space;
>     }
>  
>     /* Sanity check that we haven't over-allocated. */
> -   assert(push_constant_chunks +
> -          vs_chunks + hs_chunks + ds_chunks + gs_chunks <= urb_chunks);
> +   unsigned total_chunks = push_constant_chunks;
> +   for (int i = MESA_SHADER_VERTEX; i <= MESA_SHADER_GEOMETRY; i++) {
> +      total_chunks += chunks[i];
> +   }
> +   assert(total_chunks <= urb_chunks);
>  
>     /* Finally, compute the number of entries that can fit in the space
>      * allocated to each stage.
>      */
> -   unsigned nr_vs_entries = vs_chunks * chunk_size_bytes / vs_entry_size_bytes;
> -   unsigned nr_hs_entries = hs_chunks * chunk_size_bytes / hs_entry_size_bytes;
> -   unsigned nr_ds_entries = ds_chunks * chunk_size_bytes / ds_entry_size_bytes;
> -   unsigned nr_gs_entries = gs_chunks * chunk_size_bytes / gs_entry_size_bytes;
> +   unsigned entries[4];
> +   for (int i = MESA_SHADER_VERTEX; i <= MESA_SHADER_GEOMETRY; i++) {
> +      entries[i] = chunks[i] * chunk_size_bytes / entry_size_bytes[i];
>  
> -   /* Since we rounded up when computing *_wants, this may be slightly more
> -    * than the maximum allowed amount, so correct for that.
> -    */
> -   nr_vs_entries =
> -      MIN2(nr_vs_entries, devinfo->urb.max_entries[MESA_SHADER_VERTEX]);
> -   nr_hs_entries =
> -      MIN2(nr_hs_entries, devinfo->urb.max_entries[MESA_SHADER_TESS_CTRL]);
> -   nr_ds_entries =
> -      MIN2(nr_ds_entries, devinfo->urb.max_entries[MESA_SHADER_TESS_EVAL]);
> -   nr_gs_entries =
> -      MIN2(nr_gs_entries, devinfo->urb.max_entries[MESA_SHADER_GEOMETRY]);
> -
> -   /* Ensure that we program a multiple of the granularity. */
> -   nr_vs_entries = ROUND_DOWN_TO(nr_vs_entries, vs_granularity);
> -   nr_hs_entries = ROUND_DOWN_TO(nr_hs_entries, hs_granularity);
> -   nr_ds_entries = ROUND_DOWN_TO(nr_ds_entries, ds_granularity);
> -   nr_gs_entries = ROUND_DOWN_TO(nr_gs_entries, gs_granularity);
> -
> -   /* Finally, sanity check to make sure we have at least the minimum number
> -    * of entries needed for each stage.
> -    */
> -   assert(nr_vs_entries >= vs_min_entries);
> -   if (gs_present)
> -      assert(nr_gs_entries >= 2);
> -   if (tess_present) {
> -      assert(nr_hs_entries >= 1);
> -      assert(nr_ds_entries >= devinfo->urb.min_entries[MESA_SHADER_TESS_EVAL]);
> +      /* Since we rounded up when computing wants[], this may be slightly
> +       * more than the maximum allowed amount, so correct for that.
> +       */
> +      entries[i] = MIN2(entries[i], devinfo->urb.max_entries[i]);
> +
> +      /* Ensure that we program a multiple of the granularity. */
> +      entries[i] = ROUND_DOWN_TO(entries[i], granularity[i]);
> +
> +      /* Finally, sanity check to make sure we have at least the minimum
> +       * number of entries needed for each stage.
> +       */
> +      assert(entries[i] >= min_entries[i]);
>     }
>  
> -   /* Lay out the URB in the following order:
> -    * - push constants
> -    * - VS
> -    * - HS
> -    * - DS
> -    * - GS
> -    */
> -   unsigned vs_start = push_constant_chunks;
> -   unsigned hs_start = push_constant_chunks + vs_chunks;
> -   unsigned ds_start = push_constant_chunks + vs_chunks + hs_chunks;
> -   unsigned gs_start = push_constant_chunks + vs_chunks + hs_chunks +
> -                       ds_chunks;
> +   /* Lay out the URB in pipeline order: push constants, VS, HS, DS, GS. */
> +   unsigned start[4];
> +   start[0] = push_constant_chunks;
> +   for (int i = MESA_SHADER_TESS_CTRL; i <= MESA_SHADER_GEOMETRY; i++) {
> +      start[i] = start[i - 1] + chunks[i - 1];
> +   }
>  
>     if (brw->gen == 7 && !brw->is_haswell && !brw->is_baytrail)
>        gen7_emit_vs_workaround_flush(brw);
> -   gen7_emit_urb_state(brw,
> -                       nr_vs_entries, vs_size, vs_start,
> -                       nr_hs_entries, hs_size, hs_start,
> -                       nr_ds_entries, ds_size, ds_start,
> -                       nr_gs_entries, gs_size, gs_start);
> +
> +   BEGIN_BATCH(8);
> +   for (int i = MESA_SHADER_VERTEX; i <= MESA_SHADER_GEOMETRY; i++) {
> +      OUT_BATCH((_3DSTATE_URB_VS + i) << 16 | (2 - 2));
> +      OUT_BATCH(entries[i] |
> +                ((entry_size[i] - 1) << GEN7_URB_ENTRY_SIZE_SHIFT) |
> +                (start[i] << GEN7_URB_STARTING_ADDRESS_SHIFT));
> +   }
> +   ADVANCE_BATCH();
>  }
>  
>  const struct brw_tracked_state gen7_urb = {
> -- 
> 2.10.2
> 
> _______________________________________________
> mesa-dev mailing list
> mesa-dev at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/mesa-dev


More information about the mesa-dev mailing list