From f68d64dac01505560a53aabe2b8616685cace0c2 Mon Sep 17 00:00:00 2001
From: Jason Ekstrand <jason@jlekstrand.net>
Date: Thu, 6 Aug 2020 22:53:06 -0500
Subject: [PATCH] anv: Add support for vkCmdSetRayTracingPipelineStackSizeKHR

Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/8637>
---
 src/intel/vulkan/anv_cmd_buffer.c | 57 +++++++++++++++++++++++++++++++++++++++
 src/intel/vulkan/anv_device.c     |  8 ++++++
 src/intel/vulkan/anv_private.h    |  7 +++++
 3 files changed, 72 insertions(+)

diff --git a/src/intel/vulkan/anv_cmd_buffer.c b/src/intel/vulkan/anv_cmd_buffer.c
index db7f8c7..3ebaa48 100644
--- a/src/intel/vulkan/anv_cmd_buffer.c
+++ b/src/intel/vulkan/anv_cmd_buffer.c
@@ -518,6 +518,11 @@ void anv_CmdBindPipeline(
 
       cmd_buffer->state.rt.pipeline = rt_pipeline;
       cmd_buffer->state.rt.pipeline_dirty = true;
+
+      if (rt_pipeline->stack_size > 0) {
+         anv_CmdSetRayTracingPipelineStackSizeKHR(commandBuffer,
+                                                  rt_pipeline->stack_size);
+      }
       break;
    }
 
@@ -1591,8 +1596,60 @@ void anv_CmdSetFragmentShadingRateKHR(
    cmd_buffer->state.gfx.dirty |= ANV_CMD_DIRTY_DYNAMIC_SHADING_RATE;
 }
 
+static inline uint32_t
+ilog2_round_up(uint32_t value)
+{
+   assert(value != 0);
+   return 32 - __builtin_clz(value - 1);
+}
+
 void anv_CmdSetRayTracingPipelineStackSizeKHR(
     VkCommandBuffer                             commandBuffer,
     uint32_t                                    pipelineStackSize)
 {
+   ANV_FROM_HANDLE(anv_cmd_buffer, cmd_buffer, commandBuffer);
+   struct anv_cmd_ray_tracing_state *rt = &cmd_buffer->state.rt;
+   struct anv_device *device = cmd_buffer->device;
+
+   if (anv_batch_has_error(&cmd_buffer->batch))
+      return;
+
+   uint32_t stack_ids_per_dss = 2048; /* TODO */
+
+   unsigned stack_size_log2 = ilog2_round_up(pipelineStackSize);
+   if (stack_size_log2 < 10)
+      stack_size_log2 = 10;
+
+   if (rt->scratch.layout.total_size == 1 << stack_size_log2)
+      return;
+
+   brw_rt_compute_scratch_layout(&rt->scratch.layout, &device->info,
+                                 stack_ids_per_dss, 1 << stack_size_log2);
+
+   unsigned bucket = stack_size_log2 - 10;
+   assert(bucket < ARRAY_SIZE(device->rt_scratch_bos));
+
+   struct anv_bo *bo = p_atomic_read(&device->rt_scratch_bos[bucket]);
+   if (bo == NULL) {
+      struct anv_bo *new_bo;
+      VkResult result = anv_device_alloc_bo(device, "RT scratch",
+                                            rt->scratch.layout.total_size,
+                                            0, /* alloc_flags */
+                                            0, /* explicit_address */
+                                            &new_bo);
+      if (result != VK_SUCCESS) {
+         rt->scratch.layout.total_size = 0;
+         anv_batch_set_error(&cmd_buffer->batch, result);
+         return;
+      }
+
+      bo = p_atomic_cmpxchg(&device->rt_scratch_bos[bucket], NULL, new_bo);
+      if (bo != NULL) {
+         anv_device_release_bo(device, bo);
+      } else {
+         bo = new_bo;
+      }
+   }
+
+   rt->scratch.bo = bo;
 }
diff --git a/src/intel/vulkan/anv_device.c b/src/intel/vulkan/anv_device.c
index d177614d..9809950 100644
--- a/src/intel/vulkan/anv_device.c
+++ b/src/intel/vulkan/anv_device.c
@@ -3344,6 +3344,9 @@ VkResult anv_CreateDevice(
 
    anv_scratch_pool_init(device, &device->scratch_pool);
 
+   /* TODO(RT): Do we want some sort of data structure for this? */
+   memset(device->rt_scratch_bos, 0, sizeof(device->rt_scratch_bos));
+
    result = anv_genX(&device->info, init_device_state)(device);
    if (result != VK_SUCCESS)
       goto fail_trivial_batch_bo_and_scratch_pool;
@@ -3436,6 +3439,11 @@ void anv_DestroyDevice(
    anv_state_pool_free(&device->dynamic_state_pool, device->slice_hash);
 #endif
 
+   for (unsigned i = 0; i < ARRAY_SIZE(device->rt_scratch_bos); i++) {
+      if (device->rt_scratch_bos[i] != NULL)
+         anv_device_release_bo(device, device->rt_scratch_bos[i]);
+   }
+
    anv_scratch_pool_finish(device, &device->scratch_pool);
 
    anv_device_release_bo(device, device->workaround_bo);
diff --git a/src/intel/vulkan/anv_private.h b/src/intel/vulkan/anv_private.h
index b3a3265..ca9a087 100644
--- a/src/intel/vulkan/anv_private.h
+++ b/src/intel/vulkan/anv_private.h
@@ -51,6 +51,7 @@
 #include "dev/intel_device_info.h"
 #include "blorp/blorp.h"
 #include "compiler/brw_compiler.h"
+#include "compiler/brw_rt.h"
 #include "util/bitset.h"
 #include "util/bitscan.h"
 #include "util/macros.h"
@@ -1238,6 +1239,7 @@ struct anv_device {
     struct anv_queue  *                         queues;
 
     struct anv_scratch_pool                     scratch_pool;
+    struct anv_bo                              *rt_scratch_bos[16];
 
     pthread_mutex_t                             mutex;
     pthread_cond_t                              queue_submit;
@@ -2937,6 +2939,11 @@ struct anv_cmd_ray_tracing_state {
    struct anv_ray_tracing_pipeline *pipeline;
 
    bool pipeline_dirty;
+
+   struct {
+      struct anv_bo *bo;
+      struct brw_rt_scratch_layout layout;
+   } scratch;
 };
 
 /** State required while building cmd buffer */
-- 
2.7.4