[Mesa-dev] [PATCH 08/11] intel/isl: Add a new layout for HiZ and stencil on Sandy Bridge

Pohjolainen, Topi topi.pohjolainen at gmail.com
Thu Jun 1 09:40:53 UTC 2017


On Tue, May 30, 2017 at 05:55:17PM -0700, Jason Ekstrand wrote:
> ---
>  src/intel/isl/isl.c | 162 ++++++++++++++++++++++++++++++++++++++++++++++++++--
>  src/intel/isl/isl.h |  40 +++++++++++++
>  2 files changed, 197 insertions(+), 5 deletions(-)
> 
> diff --git a/src/intel/isl/isl.c b/src/intel/isl/isl.c
> index 77b8a40..e4d7901 100644
> --- a/src/intel/isl/isl.c
> +++ b/src/intel/isl/isl.c
> @@ -479,6 +479,12 @@ isl_choose_array_pitch_span(const struct isl_device *dev,
>         * compact QPitch possible in order to conserve memory.
>         */
>        return ISL_ARRAY_PITCH_SPAN_COMPACT;
> +
> +   case ISL_DIM_LAYOUT_GEN6_STENCIL_HIZ:
> +      /* Each array image in the gen6 stencil of HiZ surface is compact in the
> +       * sense that every LOD is a compact array of the same size as LOD0.
> +       */
> +      return ISL_ARRAY_PITCH_SPAN_COMPACT;
>     }
>  
>     unreachable("bad isl_dim_layout");
> @@ -510,10 +516,15 @@ isl_choose_image_alignment_el(const struct isl_device *dev,
>        return;
>     } else if (info->format == ISL_FORMAT_HIZ) {
>        assert(ISL_DEV_GEN(dev) >= 6);
> -      /* HiZ surfaces are always aligned to 16x8 pixels in the primary surface
> -       * which works out to 2x2 HiZ elments.
> -       */
> -      *image_align_el = isl_extent3d(2, 2, 1);
> +      if (ISL_DEV_GEN(dev) == 6) {
> +         /* HiZ surfaces on Sandy Bridge are packed tightly. */
> +         *image_align_el = isl_extent3d(1, 1, 1);
> +      } else {
> +         /* On gen7+, HiZ surfaces are always aligned to 16x8 pixels in the
> +          * primary surface which works out to 2x2 HiZ elments.
> +          */
> +         *image_align_el = isl_extent3d(2, 2, 1);
> +      }
>        return;
>     }
>  
> @@ -540,6 +551,11 @@ isl_surf_choose_dim_layout(const struct isl_device *dev,
>                             enum isl_surf_dim logical_dim,
>                             enum isl_tiling tiling)
>  {
> +   /* Sandy bridge needs a special layout for HiZ and stencil. */
> +   if (ISL_DEV_GEN(dev) == 6 &&
> +       (tiling == ISL_TILING_W || tiling == ISL_TILING_HIZ))
> +      return ISL_DIM_LAYOUT_GEN6_STENCIL_HIZ;
> +
>     if (ISL_DEV_GEN(dev) >= 9) {
>        switch (logical_dim) {
>        case ISL_SURF_DIM_1D:
> @@ -608,6 +624,7 @@ isl_calc_phys_level0_extent_sa(const struct isl_device *dev,
>  
>        case ISL_DIM_LAYOUT_GEN9_1D:
>        case ISL_DIM_LAYOUT_GEN4_2D:
> +      case ISL_DIM_LAYOUT_GEN6_STENCIL_HIZ:
>           *phys_level0_sa = (struct isl_extent4d) {
>              .w = isl_align_npot(info->width, fmtl->bw),
>              .h = fmtl->bh,
> @@ -619,7 +636,8 @@ isl_calc_phys_level0_extent_sa(const struct isl_device *dev,
>        break;
>  
>     case ISL_SURF_DIM_2D:
> -      assert(dim_layout == ISL_DIM_LAYOUT_GEN4_2D);
> +      assert(dim_layout == ISL_DIM_LAYOUT_GEN4_2D ||
> +             dim_layout == ISL_DIM_LAYOUT_GEN6_STENCIL_HIZ);
>  
>        if (tiling == ISL_TILING_Ys && info->samples > 1)
>           isl_finishme("%s:%s: multisample TileYs layout", __FILE__, __func__);
> @@ -684,6 +702,7 @@ isl_calc_phys_level0_extent_sa(const struct isl_device *dev,
>  
>        switch (dim_layout) {
>        case ISL_DIM_LAYOUT_GEN9_1D:
> +      case ISL_DIM_LAYOUT_GEN6_STENCIL_HIZ:
>           unreachable("bad isl_dim_layout");
>  
>        case ISL_DIM_LAYOUT_GEN4_2D:
> @@ -969,6 +988,67 @@ isl_calc_phys_total_extent_el_gen4_3d(
>  
>  /**
>   * A variant of isl_calc_phys_slice0_extent_sa() specific to
> + * ISL_DIM_LAYOUT_GEN6_STENCIL_HIZ.
> + */
> +static void
> +isl_calc_phys_total_extent_el_gen6_stencil_hiz(
> +      const struct isl_device *dev,
> +      const struct isl_surf_init_info *restrict info,
> +      const struct isl_tile_info *tile_info,
> +      const struct isl_extent3d *image_align_sa,
> +      const struct isl_extent4d *phys_level0_sa,
> +      uint32_t *array_pitch_el_rows,
> +      struct isl_extent2d *phys_total_el)
> +{
> +   const struct isl_format_layout *fmtl = isl_format_get_layout(info->format);
> +
> +   const struct isl_extent2d tile_extent_sa = {
> +      .w = tile_info->logical_extent_el.w * fmtl->bw,
> +      .h = tile_info->logical_extent_el.h * fmtl->bh,
> +   };
> +   /* Tile size is a multiple of image alignment */
> +   assert(tile_extent_sa.w % image_align_sa->w == 0);
> +   assert(tile_extent_sa.h % image_align_sa->h == 0);
> +
> +   const uint32_t W0 = phys_level0_sa->w;
> +   const uint32_t H0 = phys_level0_sa->h;
> +
> +   /* Each image has the same height as LOD0 because the hardware thinks
> +    * everything is LOD0
> +    */
> +   const uint32_t H = isl_align(H0, image_align_sa->h) * phys_level0_sa->a;
> +
> +   uint32_t slice_top_w = 0;
> +   uint32_t slice_bottom_w = 0;
> +   uint32_t slice_h = 0;

I don't really understand why slice_bottom_w and slice_h are prefixed with
slice, I would rather call them total_bottom_w and total_h.

> +
> +   for (uint32_t l = 0; l < info->levels; ++l) {
> +      const uint32_t W = isl_minify(W0, l);
> +
> +      const uint32_t w = isl_align(W, tile_extent_sa.w);
> +      const uint32_t h = isl_align(H, tile_extent_sa.h);
> +
> +      if (l == 0) {
> +         slice_top_w = w;
> +         slice_h = h;
> +      } else if (l == 1) {
> +         slice_bottom_w = w;
> +         slice_h += h;
> +      } else {
> +         slice_bottom_w += w;
> +      }
> +   }
> +
> +   *array_pitch_el_rows =
> +      isl_assert_div(isl_align(H0, image_align_sa->h), fmtl->bh);
> +   *phys_total_el = (struct isl_extent2d) {
> +      .w = isl_assert_div(MAX(slice_top_w, slice_bottom_w), fmtl->bw),
> +      .h = isl_assert_div(slice_h, fmtl->bh),
> +   };
> +}
> +
> +/**
> + * A variant of isl_calc_phys_slice0_extent_sa() specific to
>   * ISL_DIM_LAYOUT_GEN9_1D.
>   */
>  static void
> @@ -1035,6 +1115,14 @@ isl_calc_phys_total_extent_el(const struct isl_device *dev,
>                                              array_pitch_el_rows,
>                                              total_extent_el);
>        return;
> +   case ISL_DIM_LAYOUT_GEN6_STENCIL_HIZ:
> +      assert(array_pitch_span == ISL_ARRAY_PITCH_SPAN_COMPACT);
> +      isl_calc_phys_total_extent_el_gen6_stencil_hiz(dev, info, tile_info,
> +                                                     image_align_sa,
> +                                                     phys_level0_sa,
> +                                                     array_pitch_el_rows,
> +                                                     total_extent_el);
> +      return;
>     case ISL_DIM_LAYOUT_GEN4_3D:
>        assert(array_pitch_span == ISL_ARRAY_PITCH_SPAN_COMPACT);
>        isl_calc_phys_total_extent_el_gen4_3d(dev, info,
> @@ -1892,6 +1980,65 @@ get_image_offset_sa_gen4_3d(const struct isl_surf *surf,
>     *y_offset_sa = y;
>  }
>  
> +static void
> +get_image_offset_sa_gen6_stencil_hiz(const struct isl_surf *surf,
> +                                     uint32_t level,
> +                                     uint32_t logical_array_layer,
> +                                     uint32_t *x_offset_sa,
> +                                     uint32_t *y_offset_sa)
> +{
> +   assert(level < surf->levels);
> +   assert(surf->logical_level0_px.depth == 1);
> +   assert(logical_array_layer < surf->logical_level0_px.array_len);
> +
> +   const struct isl_format_layout *fmtl = isl_format_get_layout(surf->format);
> +
> +   const struct isl_extent3d image_align_sa =
> +      isl_surf_get_image_alignment_sa(surf);
> +
> +   struct isl_tile_info tile_info;
> +   isl_tiling_get_info(surf->tiling, fmtl->bpb, &tile_info);
> +   const struct isl_extent2d tile_extent_sa = {
> +      .w = tile_info.logical_extent_el.w * fmtl->bw,
> +      .h = tile_info.logical_extent_el.h * fmtl->bh,
> +   };
> +   /* Tile size is a multiple of image alignment */
> +   assert(tile_extent_sa.w % image_align_sa.w == 0);
> +   assert(tile_extent_sa.h % image_align_sa.h == 0);
> +
> +   const uint32_t W0 = surf->phys_level0_sa.w;
> +   const uint32_t H0 = surf->phys_level0_sa.h;
> +
> +   /* Each image has the same height as LOD0 because the hardware thinks
> +    * everything is LOD0
> +    */
> +   const uint32_t H = isl_align(H0, image_align_sa.h);
> +
> +   /* Quick sanity check for consistency */
> +   if (surf->phys_level0_sa.array_len > 1)
> +      assert(surf->array_pitch_el_rows == isl_assert_div(H, fmtl->bh));
> +
> +   uint32_t x = 0, y = 0;
> +   for (uint32_t l = 0; l < level; ++l) {
> +      const uint32_t W = isl_minify(W0, l);
> +
> +      const uint32_t w = isl_align(W, tile_extent_sa.w);
> +      const uint32_t h = isl_align(H * surf->phys_level0_sa.a,
> +                                   tile_extent_sa.h);
> +
> +      if (l == 0) {
> +         y += h;
> +      } else {
> +         x += w;

For "l == 1", "x" should still be zero?

> +      }
> +   }
> +
> +   y += H * logical_array_layer;
> +
> +   *x_offset_sa = x;
> +   *y_offset_sa = y;
> +}
> +
>  /**
>   * A variant of isl_surf_get_image_offset_sa() specific to
>   * ISL_DIM_LAYOUT_GEN9_1D.
> @@ -1961,6 +2108,11 @@ isl_surf_get_image_offset_sa(const struct isl_surf *surf,
>                                    logical_z_offset_px,
>                                    x_offset_sa, y_offset_sa);
>        break;
> +   case ISL_DIM_LAYOUT_GEN6_STENCIL_HIZ:
> +      get_image_offset_sa_gen6_stencil_hiz(surf, level, logical_array_layer +
> +                                           logical_z_offset_px,
> +                                           x_offset_sa, y_offset_sa);
> +      break;
>  
>     default:
>        unreachable("not reached");
> diff --git a/src/intel/isl/isl.h b/src/intel/isl/isl.h
> index 008ab5e..4bb3de7 100644
> --- a/src/intel/isl/isl.h
> +++ b/src/intel/isl/isl.h
> @@ -528,6 +528,46 @@ enum isl_dim_layout {
>     ISL_DIM_LAYOUT_GEN4_3D,
>  
>     /**
> +    * Special layout used for HiZ and stencil on Sandy Bridge to work around
> +    * the hardware's lack of mipmap support.  On gen6, HiZ and stencil buffers
> +    * work the same as on gen7+ except that they don't technically support
> +    * mipmapping.  That does not, however, stop us from doing it.  As far as
> +    * Sandy Bridge hardware is concerned, HiZ and stencil always operates on a
> +    * single miplevel 2D (possibly array) image.  The dimensions of that image
> +    * are NOT minified.
> +    *
> +    * In order to implement HiZ and stencil on Sandy Bridge, we create one
> +    * full-sized 2D (possibly array) image for every LOD with every image
> +    * aligned to a page boundary.  When the surface is used with the stencil
> +    * or HiZ hardware, we manually offset to the image for the given LOD.
> +    *
> +    * As a memory saving measure,  we pretend that the width of each miplevel
> +    * is minified and we place LOD1 and above below LOD0 but horizontally
> +    * adjacent to each other.  When considered as full-sized images, LOD1 and
> +    * above technically overlap.  However, since we only write to part of that
> +    * image, the hardware will never notice the overlap.
> +    *
> +    * This layout looks something like this:
> +    *
> +    *   +---------+
> +    *   |         |
> +    *   |         |
> +    *   +---------+
> +    *   |         |
> +    *   |         |
> +    *   +---------+
> +    *
> +    *   +----+ +-+ .
> +    *   |    | +-+
> +    *   +----+
> +    *
> +    *   +----+ +-+ .
> +    *   |    | +-+
> +    *   +----+
> +    */
> +   ISL_DIM_LAYOUT_GEN6_STENCIL_HIZ,
> +
> +   /**
>      * For details, see the Skylake BSpec >> Memory Views >> Common Surface
>      * Formats >> Surface Layout and Tiling >> ยป 1D Surfaces.
>      */
> -- 
> 2.5.0.400.gff86faf
> 
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