anv: Add a #define for the max binding table size

This also fixes a bug where we mis-calculate maximum binding table sizes
and may return true in vkGetDescriptorSetLayoutSupport even for sets too
large to fit in a binding table.

Fixes: ddc4069122 "anv: Implement VK_KHR_maintenance3"
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>

src/intel/vulkan/anv_descriptor_set.c

@@ -163,10 +163,10 @@ void anv_GetDescriptorSetLayoutSupport(
 
    bool supported = true;
    for (unsigned s = 0; s < MESA_SHADER_STAGES; s++) {
-      /* Our maximum binding table size is 250 and we need to reserve 8 for
-       * render targets.  240 is a nice round number.
+      /* Our maximum binding table size is 240 and we need to reserve 8 for
+       * render targets.
        */
-      if (surface_count[s] >= 240)
+      if (surface_count[s] >= MAX_BINDING_TABLE_SIZE - MAX_RTS)
          supported = false;
    }
 

src/intel/vulkan/anv_device.c

@@ -1121,7 +1121,7 @@ void anv_GetPhysicalDeviceProperties(
       .maxPerStageDescriptorSampledImages       = max_samplers,
       .maxPerStageDescriptorStorageImages       = MAX_IMAGES,
       .maxPerStageDescriptorInputAttachments    = 64,
-      .maxPerStageResources                     = 250,
+      .maxPerStageResources                     = MAX_BINDING_TABLE_SIZE - MAX_RTS,
       .maxDescriptorSetSamplers                 = 6 * max_samplers, /* number of stages * maxPerStageDescriptorSamplers */
       .maxDescriptorSetUniformBuffers           = 6 * 64,           /* number of stages * maxPerStageDescriptorUniformBuffers */
       .maxDescriptorSetUniformBuffersDynamic    = MAX_DYNAMIC_BUFFERS / 2,

src/intel/vulkan/anv_private.h

@@ -162,6 +162,18 @@ struct gen_l3_config;
 #define MAX_INLINE_UNIFORM_BLOCK_SIZE 4096
 #define MAX_INLINE_UNIFORM_BLOCK_DESCRIPTORS 32
 
+/* From the Skylake PRM Vol. 7 "Binding Table Surface State Model":
+ *
+ *    "The surface state model is used when a Binding Table Index (specified
+ *    in the message descriptor) of less than 240 is specified. In this model,
+ *    the Binding Table Index is used to index into the binding table, and the
+ *    binding table entry contains a pointer to the SURFACE_STATE."
+ *
+ * Binding table values above 240 are used for various things in the hardware
+ * such as stateless, stateless with incoherent cache, SLM, and bindless.
+ */
+#define MAX_BINDING_TABLE_SIZE 240
+
 /* The kernel relocation API has a limitation of a 32-bit delta value
  * applied to the address before it is written which, in spite of it being
  * unsigned, is treated as signed .  Because of the way that this maps to