nil: Add a ViewAccess enum and plumb it through from NVK

This lets NIL know whether a descriptor will be accessed via texture
instructions or surface instructions.

Reviewed-by: Mary Guillemard <mary.guillemard@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/36207>

src/nouveau/nil/cbindgen.toml

@@ -33,6 +33,7 @@ renaming_overrides_prefixing = true
 "SuInfo" = "nil_su_info"
 "Tiling" = "nil_tiling"
 "View" = "nil_view"
+"ViewAccess" = "nil_view_access"
 "ViewType" = "nil_view_type"
 
 # There's just no good solution for this one

src/nouveau/nil/descriptor.rs

@@ -22,11 +22,7 @@ use std::ops::Range;
 
 use crate::extent::{units, Extent4D};
 use crate::format::Format;
-use crate::image::Image;
-use crate::image::ImageDim;
-use crate::image::SampleLayout;
-use crate::image::View;
-use crate::image::ViewType;
+use crate::image::{Image, ImageDim, SampleLayout, View, ViewAccess, ViewType};
 
 macro_rules! set_enum {
     ($th:expr, $cls:ident, $field:ident, $enum:ident) => {
@@ -922,6 +918,9 @@ impl Descriptor {
                 &mut desc.bits,
             );
         } else if dev.cls_eng3d >= FERMI_A {
+            // Kepler and earlier doesn't support surface access through
+            // conventional image descriptors
+            assert_eq!(view.access, ViewAccess::Texture);
             nv9097_fill_image_view_desc(
                 image,
                 view,

src/nouveau/nil/image.rs

@@ -975,11 +975,26 @@ pub enum ViewType {
     CubeArray,
 }
 
+/// An enum describing how an image view will be accessed by the shader.
+#[allow(dead_code)]
+#[derive(Clone, Debug, Copy, PartialEq)]
+#[repr(u8)]
+pub enum ViewAccess {
+    /// This image view will be accessed via texture instructions (tex, etc.)
+    Texture,
+
+    /// This image view will be accessed as a storage image via surface
+    /// instructions (suld/sust)
+    Storage,
+}
+
 #[repr(C)]
 #[derive(Debug, Clone, PartialEq)]
 pub struct View {
     pub view_type: ViewType,
 
+    pub access: ViewAccess,
+
     /// The format to use in the view
     ///
     /// This may differ from the format of the actual isl_surf but must have the

src/nouveau/nil/su_info.rs

@@ -6,7 +6,7 @@
 
 use crate::format::Format;
 use crate::image::ViewType;
-use crate::image::{Image, SampleLayout, View};
+use crate::image::{Image, SampleLayout, View, ViewAccess};
 use bitview::{BitMutView, SetField};
 use nil_rs_bindings::*;
 
@@ -204,6 +204,7 @@ pub extern "C" fn nil_fill_su_info(
     view: &View,
     base_address: u64,
 ) -> SuInfo {
+    assert_eq!(view.access, ViewAccess::Storage);
     assert!(view.format.supports_storage(dev));
     debug_assert!(image.align_B >= 256);
     let level = &image.levels[view.base_level as usize];

src/nouveau/vulkan/nvk_image_view.c

@@ -188,6 +188,7 @@ nvk_image_view_init(struct nvk_device *dev,
 
       if (view->vk.usage & (VK_IMAGE_USAGE_SAMPLED_BIT |
                            VK_IMAGE_USAGE_INPUT_ATTACHMENT_BIT)) {
+         nil_view.access = NIL_VIEW_ACCESS_TEXTURE;
          const struct nil_descriptor desc =
             nil_image_view_descriptor(&pdev->info, &nil_image,
                                       &nil_view, base_addr);
@@ -214,6 +215,8 @@ nvk_image_view_init(struct nvk_device *dev,
       }
 
       if (view->vk.usage & VK_IMAGE_USAGE_STORAGE_BIT) {
+         nil_view.access = NIL_VIEW_ACCESS_STORAGE;
+
          /* For storage images, we can't have any cubes */
          if (view->vk.view_type == VK_IMAGE_VIEW_TYPE_CUBE ||
             view->vk.view_type == VK_IMAGE_VIEW_TYPE_CUBE_ARRAY)