agx: Defeature indirect vbufs

vb_mask can include garbage vbufs, we can't rely on it. This will
prevent a regression when switching to u_blitter based clears. This is
also simpler and shrinks the VS shader key so all in all a good thing.

Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/18380>

src/asahi/compiler/agx_compile.c

@@ -311,10 +311,7 @@ agx_emit_load_attr(agx_builder *b, agx_index *dests, nir_intrinsic_instr *instr)
    agx_index offset = agx_imad(b, element_id, shifted_stride, src_offset, 0);
 
    /* Each VBO has a 64-bit = 4 x 16-bit address, lookup the base address as a sysval */
-   unsigned num_vbos = key->vs.num_vbufs;
-   unsigned base_length = (num_vbos * 4);
-   agx_index base = agx_indexed_sysval(b->shader,
-                                       AGX_PUSH_VBO_BASES, AGX_SIZE_64, buf * 4, base_length);
+   agx_index base = agx_vbo_base(b->shader, buf);
 
    /* Load the data */
    assert(instr->num_components <= 4);

src/asahi/compiler/agx_compile.h

@@ -33,11 +33,13 @@ enum agx_push_type {
     * 16-bit sizes for optional bounds checking (SIZES) */
    AGX_PUSH_UBO_BASES,
    AGX_PUSH_UBO_SIZES,
-   AGX_PUSH_VBO_BASES,
    AGX_PUSH_VBO_SIZES,
    AGX_PUSH_SSBO_BASES,
    AGX_PUSH_SSBO_SIZES,
 
+   /* 64-bit VBO base pointer */
+   AGX_PUSH_VBO_BASE,
+
    /* Push the attached constant memory */
    AGX_PUSH_CONSTANTS,
 
@@ -79,6 +81,8 @@ struct agx_push {
          uint16_t ubo;
          uint16_t offset;
       } ubo_data;
+
+      uint32_t vbo;
    };
 };
 

src/asahi/compiler/agx_compiler.h

@@ -696,6 +696,9 @@ agx_index
 agx_indexed_sysval(agx_context *ctx, enum agx_push_type type, enum agx_size size,
       unsigned index, unsigned length);
 
+agx_index
+agx_vbo_base(agx_context *ctx, unsigned vbo);
+
 /* Routines defined for AIR */
 
 void agx_print_instr(agx_instr *I, FILE *fp);

src/asahi/compiler/agx_uniforms.c

@@ -62,3 +62,33 @@ agx_indexed_sysval(agx_context *ctx, enum agx_push_type type,
 
    return agx_uniform(base + index, size);
 }
+
+agx_index
+agx_vbo_base(agx_context *ctx, unsigned vbo)
+{
+   /* Check if we already pushed */
+   for (unsigned i = 0; i < ctx->out->push_ranges; ++i) {
+      struct agx_push push = ctx->out->push[i];
+
+      if (push.type == AGX_PUSH_VBO_BASE && push.vbo == vbo) {
+         return agx_uniform(push.base, AGX_SIZE_64);
+      }
+   }
+
+   /* Otherwise, push */
+   assert(ctx->out->push_ranges < AGX_MAX_PUSH_RANGES);
+
+   ctx->push_base = ALIGN_POT(ctx->push_base, 4);
+
+   unsigned base = ctx->push_base;
+   ctx->push_base += 4;
+
+   ctx->out->push[ctx->out->push_ranges++] = (struct agx_push) {
+      .type = AGX_PUSH_VBO_BASE,
+      .base = base,
+      .length = 4,
+      .vbo = vbo,
+   };
+
+   return agx_uniform(base, AGX_SIZE_64);
+}

src/gallium/drivers/asahi/agx_state.c

@@ -1083,9 +1083,7 @@ agx_update_shader(struct agx_context *ctx, struct agx_compiled_shader **out,
 static bool
 agx_update_vs(struct agx_context *ctx)
 {
-   struct agx_vs_shader_key key = {
-      .num_vbufs = util_last_bit(ctx->vb_mask),
-   };
+   struct agx_vs_shader_key key = { 0 };
 
    memcpy(key.attributes, ctx->attributes,
           sizeof(key.attributes[0]) * AGX_MAX_ATTRIBS);

src/gallium/drivers/asahi/agx_uniforms.c

@@ -66,21 +66,19 @@ agx_push_location_direct(struct agx_context *ctx, struct agx_push push,
       return ptr.gpu;
    }
 
-   case AGX_PUSH_VBO_BASES: {
-      unsigned count = util_last_bit(ctx->vb_mask);
-      struct agx_ptr ptr = agx_pool_alloc_aligned(&batch->pool, count * sizeof(uint64_t), 8);
-      uint64_t *addresses = ptr.cpu;
+   case AGX_PUSH_VBO_BASE: {
+      struct agx_ptr ptr = agx_pool_alloc_aligned(&batch->pool, sizeof(uint64_t), 8);
+      uint64_t *address = ptr.cpu;
 
-      u_foreach_bit(i, ctx->vb_mask) {
-         struct pipe_vertex_buffer vb = ctx->vertex_buffers[i];
+      assert(ctx->vb_mask & BITFIELD_BIT(push.vbo) && "oob");
+
+      struct pipe_vertex_buffer vb = ctx->vertex_buffers[push.vbo];
       assert(!vb.is_user_buffer);
 
       struct agx_bo *bo = agx_resource(vb.buffer.resource)->bo;
       agx_batch_add_bo(batch, bo);
 
-         addresses[i] = bo->ptr.gpu + vb.buffer_offset;
-      }
-
+      *address = bo->ptr.gpu + vb.buffer_offset;
       return ptr.gpu;
    }