i965/gen6 depth surface: program 3DSTATE_DEPTH_BUFFER to top of surface

(bf25ee2 for gen6)

Previously we would always find the 2D sub-surface of interest,
and then program the surface to this location. Now we always
program the 3DSTATE_DEPTH_BUFFER at the start of the surface.
To select the lod/slice, we utilize the lod & minimum array
element fields.

We also must disable brw_workaround_depthstencil_alignment for
gen >= 6. Now the hardware will handle alignment when rendering
to additional slices/LODs.

v3:
 * Set depth_mt bo RELOC offset to 0, as was done in bf25ee2

Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=56127

3 files changed, 50 insertions, 59 deletions

diff --git a/src/mesa/drivers/dri/i965/brw_misc_state.c b/src/mesa/drivers/dri/i965/brw_misc_state.c
index 76e22bd5ac..e3980fc340 100644
--- a/src/mesa/drivers/dri/i965/brw_misc_state.c
+++ b/src/mesa/drivers/dri/i965/brw_misc_state.c
@@ -261,10 +261,10 @@ brw_workaround_depthstencil_alignment(struct brw_context *brw,
    if (stencil_irb)
       brw->depthstencil.stencil_mt = get_stencil_miptree(stencil_irb);
 
-   /* Gen7+ doesn't require the workarounds, since we always program the
+   /* Gen6+ doesn't require the workarounds, since we always program the
     * surface state at the start of the whole surface.
     */
-   if (brw->gen >= 7)
+   if (brw->gen >= 6)
       return;
 
    /* Check if depth buffer is in depth/stencil format.  If so, then it's only
diff --git a/src/mesa/drivers/dri/i965/gen6_blorp.cpp b/src/mesa/drivers/dri/i965/gen6_blorp.cpp
index dca6bfc79b..5a56442afd 100644
--- a/src/mesa/drivers/dri/i965/gen6_blorp.cpp
+++ b/src/mesa/drivers/dri/i965/gen6_blorp.cpp
@@ -787,10 +787,6 @@ static void
 gen6_blorp_emit_depth_stencil_config(struct brw_context *brw,
                                      const brw_blorp_params *params)
 {
-   struct gl_context *ctx = &brw->ctx;
-   uint32_t draw_x = params->depth.x_offset;
-   uint32_t draw_y = params->depth.y_offset;
-   uint32_t tile_mask_x, tile_mask_y;
    uint32_t surfwidth, surfheight;
    uint32_t surftype;
    unsigned int depth = MAX2(params->depth.mt->logical_depth0, 1);
@@ -814,12 +810,6 @@ gen6_blorp_emit_depth_stencil_config(struct brw_context *brw,
       break;
    }
 
-   brw_get_depthstencil_tile_masks(params->depth.mt,
-                                   params->depth.level,
-                                   params->depth.layer,
-                                   NULL,
-                                   &tile_mask_x, &tile_mask_y);
-
    min_array_element = params->depth.layer;
 
    lod = params->depth.level - params->depth.mt->first_level;
@@ -838,55 +828,42 @@ gen6_blorp_emit_depth_stencil_config(struct brw_context *brw,
 
    /* 3DSTATE_DEPTH_BUFFER */
    {
-      uint32_t tile_x = draw_x & tile_mask_x;
-      uint32_t tile_y = draw_y & tile_mask_y;
-      uint32_t offset =
-         intel_miptree_get_aligned_offset(params->depth.mt,
-                                          draw_x & ~tile_mask_x,
-                                          draw_y & ~tile_mask_y, false);
-
-      /* According to the Sandy Bridge PRM, volume 2 part 1, pp326-327
-       * (3DSTATE_DEPTH_BUFFER dw5), in the documentation for "Depth
-       * Coordinate Offset X/Y":
-       *
-       *   "The 3 LSBs of both offsets must be zero to ensure correct
-       *   alignment"
-       *
-       * We have no guarantee that tile_x and tile_y are correctly aligned,
-       * since they are determined by the mipmap layout, which is only aligned
-       * to multiples of 4.
-       *
-       * So, to avoid hanging the GPU, just smash the low order 3 bits of
-       * tile_x and tile_y to 0.  This is a temporary workaround until we come
-       * up with a better solution.
-       */
-      WARN_ONCE((tile_x & 7) || (tile_y & 7),
-                "Depth/stencil buffer needs alignment to 8-pixel boundaries.\n"
-                "Truncating offset, bad rendering may occur.\n");
-      tile_x &= ~7;
-      tile_y &= ~7;
-
       intel_emit_post_sync_nonzero_flush(brw);
       intel_emit_depth_stall_flushes(brw);
 
       BEGIN_BATCH(7);
+      /* 3DSTATE_DEPTH_BUFFER dw0 */
       OUT_BATCH(_3DSTATE_DEPTH_BUFFER << 16 | (7 - 2));
+
+      /* 3DSTATE_DEPTH_BUFFER dw1 */
       OUT_BATCH((params->depth.mt->pitch - 1) |
                 params->depth_format << 18 |
                 1 << 21 | /* separate stencil enable */
                 1 << 22 | /* hiz enable */
                 BRW_TILEWALK_YMAJOR << 26 |
                 1 << 27 | /* y-tiled */
-                BRW_SURFACE_2D << 29);
+                surftype << 29);
+
+      /* 3DSTATE_DEPTH_BUFFER dw2 */
       OUT_RELOC(params->depth.mt->bo,
                 I915_GEM_DOMAIN_RENDER, I915_GEM_DOMAIN_RENDER,
-                offset);
+                0);
+
+      /* 3DSTATE_DEPTH_BUFFER dw3 */
       OUT_BATCH(BRW_SURFACE_MIPMAPLAYOUT_BELOW << 1 |
-                (params->depth.width + tile_x - 1) << 6 |
-                (params->depth.height + tile_y - 1) << 19);
+                (surfwidth - 1) << 6 |
+                (surfheight - 1) << 19 |
+                lod << 2);
+
+      /* 3DSTATE_DEPTH_BUFFER dw4 */
+      OUT_BATCH((depth - 1) << 21 |
+                min_array_element << 10 |
+                (depth - 1) << 1);
+
+      /* 3DSTATE_DEPTH_BUFFER dw5 */
       OUT_BATCH(0);
-      OUT_BATCH(tile_x |
-                tile_y << 16);
+
+      /* 3DSTATE_DEPTH_BUFFER dw6 */
       OUT_BATCH(0);
       ADVANCE_BATCH();
    }
@@ -894,17 +871,13 @@ gen6_blorp_emit_depth_stencil_config(struct brw_context *brw,
    /* 3DSTATE_HIER_DEPTH_BUFFER */
    {
       struct intel_mipmap_tree *hiz_mt = params->depth.mt->hiz_mt;
-      uint32_t hiz_offset =
-         intel_miptree_get_aligned_offset(hiz_mt,
-                                          draw_x & ~tile_mask_x,
-                                          (draw_y & ~tile_mask_y) / 2, false);
 
       BEGIN_BATCH(3);
       OUT_BATCH((_3DSTATE_HIER_DEPTH_BUFFER << 16) | (3 - 2));
       OUT_BATCH(hiz_mt->pitch - 1);
       OUT_RELOC(hiz_mt->bo,
                 I915_GEM_DOMAIN_RENDER, I915_GEM_DOMAIN_RENDER,
-                hiz_offset);
+                0);
       ADVANCE_BATCH();
    }
 
diff --git a/src/mesa/drivers/dri/i965/gen6_depth_state.c b/src/mesa/drivers/dri/i965/gen6_depth_state.c
index abb21246d4..2bd2566d7b 100644
--- a/src/mesa/drivers/dri/i965/gen6_depth_state.c
+++ b/src/mesa/drivers/dri/i965/gen6_depth_state.c
@@ -51,6 +51,7 @@ gen6_emit_depth_stencil_hiz(struct brw_context *brw,
    unsigned int min_array_element;
    GLenum gl_target = GL_TEXTURE_2D;
    unsigned int lod;
+   const struct intel_mipmap_tree *mt = depth_mt ? depth_mt : stencil_mt;
    const struct intel_renderbuffer *irb = NULL;
    const struct gl_renderbuffer *rb = NULL;
 
@@ -112,6 +113,11 @@ gen6_emit_depth_stencil_hiz(struct brw_context *brw,
 
    lod = irb ? irb->mt_level - irb->mt->first_level : 0;
 
+   if (mt) {
+      width = mt->logical_width0;
+      height = mt->logical_height0;
+   }
+
    unsigned int len;
    if (brw->gen >= 6)
       len = 7;
@@ -121,7 +127,10 @@ gen6_emit_depth_stencil_hiz(struct brw_context *brw,
       len = 5;
 
    BEGIN_BATCH(len);
+   /* 3DSTATE_DEPTH_BUFFER dw0 */
    OUT_BATCH(_3DSTATE_DEPTH_BUFFER << 16 | (len - 2));
+
+   /* 3DSTATE_DEPTH_BUFFER dw1 */
    OUT_BATCH((depth_mt ? depth_mt->pitch - 1 : 0) |
              (depthbuffer_format << 18) |
              ((enable_hiz_ss ? 1 : 0) << 21) | /* separate stencil enable */
@@ -129,25 +138,34 @@ gen6_emit_depth_stencil_hiz(struct brw_context *brw,
              (BRW_TILEWALK_YMAJOR << 26) |
              ((depth_mt ? depth_mt->tiling != I915_TILING_NONE : 1)
               << 27) |
-             (depth_surface_type << 29));
+             (surftype << 29));
 
+   /* 3DSTATE_DEPTH_BUFFER dw2 */
    if (depth_mt) {
       OUT_RELOC(depth_mt->bo,
 		I915_GEM_DOMAIN_RENDER, I915_GEM_DOMAIN_RENDER,
-		depth_offset);
+		0);
    } else {
       OUT_BATCH(0);
    }
 
-   OUT_BATCH(((width + tile_x - 1) << 6) |
-             ((height + tile_y - 1) << 19));
-   OUT_BATCH(0);
+   /* 3DSTATE_DEPTH_BUFFER dw3 */
+   OUT_BATCH(((width - 1) << 6) |
+             ((height - 1) << 19) |
+             lod << 2);
 
+   /* 3DSTATE_DEPTH_BUFFER dw4 */
+   OUT_BATCH((depth - 1) << 21 |
+             min_array_element << 10 |
+             (depth - 1) << 1);
+
+   /* 3DSTATE_DEPTH_BUFFER dw5 */
    if (brw->is_g4x || brw->gen >= 5)
-      OUT_BATCH(tile_x | (tile_y << 16));
+      OUT_BATCH(0);
    else
       assert(tile_x == 0 && tile_y == 0);
 
+   /* 3DSTATE_DEPTH_BUFFER dw6 */
    if (brw->gen >= 6)
       OUT_BATCH(0);
 
@@ -170,7 +188,7 @@ gen6_emit_depth_stencil_hiz(struct brw_context *brw,
 	 OUT_BATCH(hiz_mt->pitch - 1);
 	 OUT_RELOC(hiz_mt->bo,
 		   I915_GEM_DOMAIN_RENDER, I915_GEM_DOMAIN_RENDER,
-		   brw->depthstencil.hiz_offset);
+		   0);
 	 ADVANCE_BATCH();
       } else {
 	 BEGIN_BATCH(3);
@@ -192,7 +210,7 @@ gen6_emit_depth_stencil_hiz(struct brw_context *brw,
 	 OUT_BATCH(2 * stencil_mt->pitch - 1);
 	 OUT_RELOC(stencil_mt->bo,
 		   I915_GEM_DOMAIN_RENDER, I915_GEM_DOMAIN_RENDER,
-		   brw->depthstencil.stencil_offset);
+		   0);
 	 ADVANCE_BATCH();
       } else {
 	 BEGIN_BATCH(3);