i965: Make calculate_attr_overrides return the URB read offset.

Traditionally, we've hardcoded "URB Entry Read Offset" to 1 (which
represents 2 vec4 varying slots) to skip over the 8 DWord VUE header.

In order to support ARB_fragment_layer_viewport, we'll need to read
from that header.  This patch adds the basic plumbing necessary to
calculate a value dynamically and hook it up in the SBE packets.

Signed-off-by: Kenneth Graunke <[email protected]>
Reviewed-by: Chris Forbes <[email protected]>

4 files changed, 17 insertions, 10 deletions

diff --git a/src/mesa/drivers/dri/i965/brw_state.h b/src/mesa/drivers/dri/i965/brw_state.h
index 6fc9c14f6b4..78389011015 100644
--- a/src/mesa/drivers/dri/i965/brw_state.h
+++ b/src/mesa/drivers/dri/i965/brw_state.h
@@ -345,7 +345,8 @@ calculate_attr_overrides(const struct brw_context *brw,
                          uint16_t *attr_overrides,
                          uint32_t *point_sprite_enables,
                          uint32_t *flat_enables,
-                         uint32_t *urb_entry_read_length);
+                         uint32_t *urb_entry_read_length,
+                         uint32_t *urb_entry_read_offset);
 
 /* gen6_surface_state.c */
 void gen6_init_vtable_surface_functions(struct brw_context *brw);
diff --git a/src/mesa/drivers/dri/i965/gen6_sf_state.c b/src/mesa/drivers/dri/i965/gen6_sf_state.c
index 4068f2844a2..0c8c05304f5 100644
--- a/src/mesa/drivers/dri/i965/gen6_sf_state.c
+++ b/src/mesa/drivers/dri/i965/gen6_sf_state.c
@@ -159,14 +159,16 @@ calculate_attr_overrides(const struct brw_context *brw,
                          uint16_t *attr_overrides,
                          uint32_t *point_sprite_enables,
                          uint32_t *flat_enables,
-                         uint32_t *urb_entry_read_length)
+                         uint32_t *urb_entry_read_length,
+                         uint32_t *urb_entry_read_offset)
 {
-   const int urb_entry_read_offset = BRW_SF_URB_ENTRY_READ_OFFSET;
    uint32_t max_source_attr = 0;
 
    *point_sprite_enables = 0;
    *flat_enables = 0;
 
+   *urb_entry_read_offset = BRW_SF_URB_ENTRY_READ_OFFSET;
+
    /* _NEW_LIGHT */
    bool shade_model_flat = brw->ctx.Light.ShadeModel == GL_FLAT;
 
@@ -228,7 +230,7 @@ calculate_attr_overrides(const struct brw_context *brw,
       /* BRW_NEW_VUE_MAP_GEOM_OUT | _NEW_LIGHT | _NEW_PROGRAM */
       uint16_t attr_override = point_sprite ? 0 :
          get_attr_override(&brw->vue_map_geom_out,
-			   urb_entry_read_offset, attr,
+			   *urb_entry_read_offset, attr,
                            brw->ctx.VertexProgram._TwoSideEnabled,
                            &max_source_attr);
 
@@ -276,7 +278,6 @@ upload_sf_state(struct brw_context *brw)
    bool render_to_fbo = _mesa_is_user_fbo(ctx->DrawBuffer);
    const bool multisampled_fbo = _mesa_geometric_samples(ctx->DrawBuffer) > 1;
 
-   const int urb_entry_read_offset = BRW_SF_URB_ENTRY_READ_OFFSET;
    float point_size;
    uint16_t attr_overrides[16];
    uint32_t point_sprite_origin;
@@ -411,8 +412,10 @@ upload_sf_state(struct brw_context *brw)
     * _NEW_POINT | _NEW_LIGHT | _NEW_PROGRAM | BRW_NEW_FS_PROG_DATA
     */
    uint32_t urb_entry_read_length;
+   uint32_t urb_entry_read_offset;
    calculate_attr_overrides(brw, attr_overrides, &point_sprite_enables,
-                            &flat_enables, &urb_entry_read_length);
+                            &flat_enables, &urb_entry_read_length,
+                            &urb_entry_read_offset);
    dw1 |= (urb_entry_read_length << GEN6_SF_URB_ENTRY_READ_LENGTH_SHIFT |
            urb_entry_read_offset << GEN6_SF_URB_ENTRY_READ_OFFSET_SHIFT);
 
diff --git a/src/mesa/drivers/dri/i965/gen7_sf_state.c b/src/mesa/drivers/dri/i965/gen7_sf_state.c
index 698b3d491bc..b1f13aceba4 100644
--- a/src/mesa/drivers/dri/i965/gen7_sf_state.c
+++ b/src/mesa/drivers/dri/i965/gen7_sf_state.c
@@ -40,7 +40,6 @@ upload_sbe_state(struct brw_context *brw)
    uint32_t point_sprite_enables;
    uint32_t flat_enables;
    int i;
-   const int urb_entry_read_offset = BRW_SF_URB_ENTRY_READ_OFFSET;
    uint16_t attr_overrides[16];
    /* _NEW_BUFFERS */
    bool render_to_fbo = _mesa_is_user_fbo(ctx->DrawBuffer);
@@ -65,8 +64,10 @@ upload_sbe_state(struct brw_context *brw)
     * _NEW_POINT | _NEW_LIGHT | _NEW_PROGRAM | BRW_NEW_FS_PROG_DATA
     */
    uint32_t urb_entry_read_length;
+   uint32_t urb_entry_read_offset;
    calculate_attr_overrides(brw, attr_overrides, &point_sprite_enables,
-                            &flat_enables, &urb_entry_read_length);
+                            &flat_enables, &urb_entry_read_length,
+                            &urb_entry_read_offset);
    dw1 |= urb_entry_read_length << GEN7_SBE_URB_ENTRY_READ_LENGTH_SHIFT |
           urb_entry_read_offset << GEN7_SBE_URB_ENTRY_READ_OFFSET_SHIFT;
 
diff --git a/src/mesa/drivers/dri/i965/gen8_sf_state.c b/src/mesa/drivers/dri/i965/gen8_sf_state.c
index 6b655ee493e..8b6f31f3be6 100644
--- a/src/mesa/drivers/dri/i965/gen8_sf_state.c
+++ b/src/mesa/drivers/dri/i965/gen8_sf_state.c
@@ -37,6 +37,7 @@ upload_sbe(struct brw_context *brw)
    uint32_t num_outputs = brw->wm.prog_data->num_varying_inputs;
    uint16_t attr_overrides[VARYING_SLOT_MAX];
    uint32_t urb_entry_read_length;
+   uint32_t urb_entry_read_offset;
    uint32_t point_sprite_enables;
    uint32_t flat_enables;
    int sbe_cmd_length;
@@ -66,7 +67,8 @@ upload_sbe(struct brw_context *brw)
    calculate_attr_overrides(brw, attr_overrides,
                             &point_sprite_enables,
                             &flat_enables,
-                            &urb_entry_read_length);
+                            &urb_entry_read_length,
+                            &urb_entry_read_offset);
 
    /* Typically, the URB entry read length and offset should be programmed in
     * 3DSTATE_VS and 3DSTATE_GS; SBE inherits it from the last active stage
@@ -78,7 +80,7 @@ upload_sbe(struct brw_context *brw)
     */
    dw1 |=
       urb_entry_read_length << GEN7_SBE_URB_ENTRY_READ_LENGTH_SHIFT |
-      BRW_SF_URB_ENTRY_READ_OFFSET << GEN8_SBE_URB_ENTRY_READ_OFFSET_SHIFT |
+      urb_entry_read_offset << GEN8_SBE_URB_ENTRY_READ_OFFSET_SHIFT |
       GEN8_SBE_FORCE_URB_ENTRY_READ_LENGTH |
       GEN8_SBE_FORCE_URB_ENTRY_READ_OFFSET;