[Mesa-dev] [PATCH 02/18] anv/image: Add anv_layout_to_aux_usage()

[Nanley Chery]

This function supersedes layout_to_hiz_usage().

Signed-off-by: Nanley Chery <nanley.g.chery at intel.com>
---
 src/intel/vulkan/anv_image.c   | 149 +++++++++++++++++++++++++++++++++++++++++
 src/intel/vulkan/anv_private.h |   4 ++
 2 files changed, 153 insertions(+)

diff --git a/src/intel/vulkan/anv_image.c b/src/intel/vulkan/anv_image.c
index cd142938e7..716cdf3a38 100644
--- a/src/intel/vulkan/anv_image.c
+++ b/src/intel/vulkan/anv_image.c
@@ -432,6 +432,155 @@ void anv_GetImageSubresourceLayout(
    }
 }
 
+/**
+ * @brief This function determines the optimal buffer to use for device
+ * accesses given a VkImageLayout and other pieces of information needed to
+ * make that determination. Device accesses may include normal sampling and
+ * rendering operations or resolves.
+ *
+ * @param gen The generation of the Intel GPU.
+ * @param image The image that may contain a collection of buffers.
+ * @param aspects The aspect(s) of the image to be accessed.
+ * @param layout The current layout of the image aspect(s).
+ * @param future_layout The next layout of the image aspect(s), if known.
+ *                      Otherwise this should be equal to the current layout.
+ *
+ * @return The primary buffer that should be used for the given layout.
+ */
+enum isl_aux_usage
+anv_layout_to_aux_usage(const uint8_t gen, const struct anv_image * const image,
+                        const VkImageAspectFlags aspects, VkImageLayout layout,
+                        const VkImageLayout future_layout)
+{
+   /* Validate the inputs. */
+
+   /* Intel GPUs prior to Gen7 are not supported in anv. */
+   assert(gen >= 7);
+
+   /* The layout of a NULL image is not properly defined. */
+   assert(image != NULL);
+
+   /* The aspects must be a subset of the image aspects. */
+   assert(aspects & image->aspects && aspects <= image->aspects);
+
+   /* According to the Vulkan Spec, the following layouts are valid only as
+    * initial layouts in a layout transition and don't support device access.
+    * Therefore, the caller should not be setting the future layout to either.
+    */
+   assert(future_layout != VK_IMAGE_LAYOUT_UNDEFINED &&
+          future_layout != VK_IMAGE_LAYOUT_PREINITIALIZED);
+
+   /* Determine the optimal buffer. */
+
+   /* If there is no auxiliary surface allocated, we must use the one and only
+    * main buffer.
+    */
+   if (image->aux_surface.isl.size == 0)
+      return ISL_AUX_USAGE_NONE;
+
+   /* All images that use an auxiliary surface are required to be tiled. */
+   assert(image->tiling == VK_IMAGE_TILING_OPTIMAL);
+
+   /* On BDW+, when clearing the stencil aspect of a depth stencil image,
+    * the HiZ buffer allows us to record the clear with a relatively small
+    * number of packets. Prior to BDW, the HiZ buffer provides no known benefit
+    * to the stencil aspect.
+    */
+   if (gen < 8 && aspects == VK_IMAGE_ASPECT_STENCIL_BIT)
+      return ISL_AUX_USAGE_NONE;
+
+   /* The undefined layout indicates that the user doesn't care about the data
+    * that's currently in the buffer. Therefore, the optimal buffer to use is
+    * the same buffer that would be used in the next layout. This avoids the
+    * possibility of having to resolve in order to maintain coherency.
+    *
+    * The pre-initialized layout is undefined for optimally-tiled images. As
+    * guaranteed by the assertion above, all images that have reached this
+    * point are tiled.
+   */
+   if (layout == VK_IMAGE_LAYOUT_UNDEFINED ||
+       layout == VK_IMAGE_LAYOUT_PREINITIALIZED)
+      layout = future_layout;
+
+   const bool has_depth = aspects & VK_IMAGE_ASPECT_DEPTH_BIT;
+   const bool color_aspect = aspects == VK_IMAGE_ASPECT_COLOR_BIT;
+
+   /* The following switch currently only handles depth stencil aspects.
+    * TODO: Handle the color aspect.
+    */
+   if (color_aspect)
+      return image->aux_usage;
+
+   switch (layout) {
+
+   /* Invalid Layouts */
+   case VK_IMAGE_LAYOUT_UNDEFINED:
+   case VK_IMAGE_LAYOUT_PREINITIALIZED:
+   case VK_IMAGE_LAYOUT_RANGE_SIZE:
+   case VK_IMAGE_LAYOUT_MAX_ENUM:
+      unreachable("Invalid image layout.");
+
+
+   /* Transfer Layouts
+    *
+    * This buffer could be a depth buffer used in a transfer operation. BLORP
+    * currently doesn't use HiZ for transfer operations so we must use the main
+    * buffer for this layout. TODO: Enable HiZ in BLORP.
+    */
+   case VK_IMAGE_LAYOUT_GENERAL:
+   case VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL:
+   case VK_IMAGE_LAYOUT_TRANSFER_SRC_OPTIMAL:
+      return ISL_AUX_USAGE_NONE;
+
+
+   /* Sampling Layouts */
+   case VK_IMAGE_LAYOUT_DEPTH_STENCIL_READ_ONLY_OPTIMAL:
+      assert(!color_aspect);
+      /* Fall-through */
+   case VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL:
+      if (has_depth && anv_can_sample_with_hiz(gen, image->samples))
+         return ISL_AUX_USAGE_HIZ;
+      else
+         return ISL_AUX_USAGE_NONE;
+
+   case VK_IMAGE_LAYOUT_PRESENT_SRC_KHR:
+      assert(color_aspect);
+
+      /* On SKL+, the render buffer can be decompressed by the presentation
+       * engine. Support for this feature has not yet landed in the wider
+       * ecosystem. TODO: Update this code when support lands.
+       *
+       * From the BDW PRM, Vol 7, Render Target Resolve:
+       *
+       *    If the MCS is enabled on a non-multisampled render target, the
+       *    render target must be resolved before being used for other
+       *    purposes (display, texture, CPU lock) The clear value from
+       *    SURFACE_STATE is written into pixels in the render target
+       *    indicated as clear in the MCS.
+       *
+       * Pre-SKL, the render buffer must be resolved before being used for
+       * presentation. We can infer that the auxiliary buffer is not used.
+       */
+      return ISL_AUX_USAGE_NONE;
+
+
+   /* Rendering Layouts */
+   case VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL:
+      assert(color_aspect);
+      unreachable("Color images are not yet supported.");
+
+   case VK_IMAGE_LAYOUT_DEPTH_STENCIL_ATTACHMENT_OPTIMAL:
+      assert(!color_aspect);
+      return ISL_AUX_USAGE_HIZ;
+   }
+
+   /* If the layout isn't recognized in the exhaustive switch above, the
+    * VkImageLayout value is not defined in vulkan.h.
+    */
+   unreachable("layout is not a VkImageLayout enumeration member.");
+}
+
+
 static struct anv_state
 alloc_surface_state(struct anv_device *device)
 {
diff --git a/src/intel/vulkan/anv_private.h b/src/intel/vulkan/anv_private.h
index 2527c2cc5a..5ce9027f88 100644
--- a/src/intel/vulkan/anv_private.h
+++ b/src/intel/vulkan/anv_private.h
@@ -1671,6 +1671,10 @@ anv_gen8_hiz_op_resolve(struct anv_cmd_buffer *cmd_buffer,
                         const struct anv_image *image,
                         enum blorp_hiz_op op);
 
+enum isl_aux_usage
+anv_layout_to_aux_usage(const uint8_t gen, const struct anv_image *image,
+                        const VkImageAspectFlags aspects, VkImageLayout layout,
+                        const VkImageLayout future_layout);
 static inline uint32_t
 anv_get_layerCount(const struct anv_image *image,
                    const VkImageSubresourceRange *range)
-- 
2.11.1