hk,asahi: move scratch BO to common

gl needs this too.

Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/35797>

src/asahi/lib/agx_abi.h

@@ -57,3 +57,5 @@
  */
 #define AGX_ZERO_PAGE_ADDRESS (((uint64_t)1) << 32)
 #define AGX_ZERO_PAGE_SIZE    (16384)
+
+#define AGX_SCRATCH_PAGE_ADDRESS (AGX_ZERO_PAGE_ADDRESS + AGX_ZERO_PAGE_SIZE)

src/asahi/lib/agx_device.c

@@ -676,6 +676,23 @@ agx_open_device(void *memctx, struct agx_device *dev)
       dev->zero_bo = bo;
    }
 
+   {
+      void *bo = agx_bo_create(dev, AIL_PAGESIZE, 0, 0, "Scratch page");
+      int ret = agx_bo_bind(dev, bo, AGX_SCRATCH_PAGE_ADDRESS, AIL_PAGESIZE, 0,
+                            DRM_ASAHI_BIND_READ | DRM_ASAHI_BIND_WRITE);
+      if (ret) {
+         fprintf(stderr, "Failed to bind zero page");
+         return false;
+      }
+
+      dev->scratch_bo = bo;
+
+      /* The contents of the scratch page are undefined, but making them nonzero
+       * helps fuzz for bugs where we incorrectly read from the write section.
+       */
+      memset(agx_bo_map(dev->scratch_bo), 0xCA, AIL_PAGESIZE);
+   }
+
    void *bo = agx_bo_create(dev, LIBAGX_PRINTF_BUFFER_SIZE, 0, AGX_BO_WRITEBACK,
                             "Printf/abort");
 
@@ -696,6 +713,7 @@ agx_close_device(struct agx_device *dev)
 {
    agx_bo_unreference(dev, dev->printf.bo);
    agx_bo_unreference(dev, dev->zero_bo);
+   agx_bo_unreference(dev, dev->scratch_bo);
    u_printf_destroy(&dev->printf);
    agx_bo_cache_evict_all(dev);
    util_sparse_array_finish(&dev->bo_map);

src/asahi/lib/agx_device.h

@@ -134,7 +134,7 @@ struct agx_device {
     */
    uint64_t sparse_ro_offset;
 
-   struct agx_bo *zero_bo;
+   struct agx_bo *zero_bo, *scratch_bo;
 
    struct renderonly *ro;
 

src/asahi/vulkan/hk_buffer.c

@@ -85,7 +85,7 @@ hk_bind_scratch(struct hk_device *dev, struct agx_va *va, unsigned offset_B,
    uint32_t flags = DRM_ASAHI_BIND_READ | DRM_ASAHI_BIND_SINGLE_PAGE;
 
    /* Map read-write scratch to the primary (bottom half) VA range */
-   int ret = agx_bo_bind(&dev->dev, dev->sparse.write, addr, size_B, 0,
+   int ret = agx_bo_bind(&dev->dev, dev->dev.scratch_bo, addr, size_B, 0,
                          flags | DRM_ASAHI_BIND_WRITE);
    if (ret)
       return VK_ERROR_UNKNOWN;

src/asahi/vulkan/hk_device.c

@@ -60,17 +60,9 @@ hk_upload_rodata(struct hk_device *dev)
    dev->rodata.bo =
       agx_bo_create(&dev->dev, AGX_SAMPLER_LENGTH, 0, 0, "Read only data");
 
-   dev->sparse.write =
-      agx_bo_create(&dev->dev, AIL_PAGESIZE, 0, 0, "Sparse write page");
-
-   if (!dev->rodata.bo || !dev->sparse.write)
+   if (!dev->rodata.bo)
       return VK_ERROR_OUT_OF_HOST_MEMORY;
 
-   /* The contents of sparse.write are undefined, but making them nonzero helps
-    * fuzz for bugs where we incorrectly read from the write section.
-    */
-   memset(agx_bo_map(dev->sparse.write), 0xCA, AIL_PAGESIZE);
-
    uint8_t *map = agx_bo_map(dev->rodata.bo);
    uint32_t offs = 0;
 
@@ -507,7 +499,6 @@ fail_queue:
    hk_queue_finish(dev, &dev->queue);
 fail_rodata:
    agx_bo_unreference(&dev->dev, dev->rodata.bo);
-   agx_bo_unreference(&dev->dev, dev->sparse.write);
 fail_bg_eot:
    agx_bg_eot_cleanup(&dev->bg_eot);
 fail_internal_shaders_2:
@@ -564,7 +555,6 @@ hk_DestroyDevice(VkDevice _device, const VkAllocationCallbacks *pAllocator)
    hk_descriptor_table_finish(dev, &dev->images);
    hk_descriptor_table_finish(dev, &dev->occlusion_queries);
    agx_bo_unreference(&dev->dev, dev->rodata.bo);
-   agx_bo_unreference(&dev->dev, dev->sparse.write);
    agx_bo_unreference(&dev->dev, dev->heap);
    agx_bg_eot_cleanup(&dev->bg_eot);
    agx_close_device(&dev->dev);

src/asahi/vulkan/hk_device.h

@@ -88,14 +88,6 @@ struct hk_device {
       uint64_t heap;
    } rodata;
 
-   /* Pages for backing sparse resources */
-   struct {
-      /* Undefined content, should not be read (except for atomics where the
-       * result is already undefined).
-       */
-      struct agx_bo *write;
-   } sparse;
-
    struct hk_internal_shaders prolog_epilog;
    struct hk_internal_shaders kernels;
    struct hk_api_shader *null_fs;

src/asahi/vulkan/hk_queue.c

@@ -476,7 +476,7 @@ hk_flush_bind(struct hk_bind_builder *b)
    struct drm_asahi_gem_bind_op op;
    if (!b->mem) {
       op = (struct drm_asahi_gem_bind_op){
-         .handle = b->dev->sparse.write->uapi_handle,
+         .handle = b->dev->dev.scratch_bo->uapi_handle,
          .flags = DRM_ASAHI_BIND_READ | DRM_ASAHI_BIND_WRITE |
                   DRM_ASAHI_BIND_SINGLE_PAGE,
          .addr = b->va->addr + b->resourceOffset,