pvr: Add pvr_bo_cpu_map_unchanged() helper to load saved vbits on map

When HAVE_VALGRIND is set, vbits of the CPU mapping are stored when
pvr_bo_cpu_unmap() is called. They can be reloaded by calling
pvr_bo_cpu_map_unchanged() instead of pvr_bo_cpu_map(). The vbits are
not loaded by default on every map, since they could easily have been
changed by the device between the unmap/map calls. Only use
pvr_bo_cpu_map_unchanged() when you can safely assume that nothing has
changed in the underlying memory.

When HAVE_VALGRIND is not set, pvr_bo_cpu_map_unchanged() just inlines
to pvr_bo_cpu_map().

Signed-off-by: Matt Coster <matt.coster@imgtec.com>
Reviewed-by: Karmjit Mahil <Karmjit.Mahil@imgtec.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/18948>

src/imagination/vulkan/pvr_bo.c

@@ -171,8 +171,23 @@ void *pvr_bo_cpu_map(struct pvr_device *device, struct pvr_bo *pvr_bo)
  */
 void pvr_bo_cpu_unmap(struct pvr_device *device, struct pvr_bo *pvr_bo)
 {
-   assert(pvr_bo->bo->map);
-   device->ws->ops->buffer_unmap(pvr_bo->bo);
+   struct pvr_winsys_bo *bo = pvr_bo->bo;
+
+   assert(bo->map);
+
+#if defined(HAVE_VALGRIND)
+   if (!bo->vbits)
+      bo->vbits = vk_alloc(&device->vk.alloc,
+                           bo->size,
+                           8,
+                           VK_SYSTEM_ALLOCATION_SCOPE_OBJECT);
+   if (bo->vbits)
+      VALGRIND_GET_VBITS(bo->map, bo->vbits, bo->size);
+   else
+      mesa_loge("Failed to alloc vbits storage; expect bad valgrind results.");
+#endif /* defined(HAVE_VALGRIND) */
+
+   device->ws->ops->buffer_unmap(bo);
 }
 
 /**
@@ -188,6 +203,10 @@ void pvr_bo_free(struct pvr_device *device, struct pvr_bo *pvr_bo)
    if (!pvr_bo)
       return;
 
+#if defined(HAVE_VALGRIND)
+   vk_free(&device->vk.alloc, pvr_bo->bo->vbits);
+#endif /* defined(HAVE_VALGRIND) */
+
    device->ws->ops->vma_unmap(pvr_bo->vma);
    device->ws->ops->heap_free(pvr_bo->vma);
 
@@ -198,3 +217,14 @@ void pvr_bo_free(struct pvr_device *device, struct pvr_bo *pvr_bo)
 
    vk_free(&device->vk.alloc, pvr_bo);
 }
+
+#if defined(HAVE_VALGRIND)
+void *pvr_bo_cpu_map_unchanged(struct pvr_device *device, struct pvr_bo *pvr_bo)
+{
+   void *ret = pvr_bo_cpu_map(device, pvr_bo);
+   if (ret)
+      VALGRIND_SET_VBITS(pvr_bo->bo->map, pvr_bo->bo->vbits, pvr_bo->bo->size);
+
+   return ret;
+}
+#endif /* defined(HAVE_VALGRIND) */

src/imagination/vulkan/pvr_bo.h

@@ -87,4 +87,15 @@ void *pvr_bo_cpu_map(struct pvr_device *device, struct pvr_bo *bo);
 void pvr_bo_cpu_unmap(struct pvr_device *device, struct pvr_bo *bo);
 void pvr_bo_free(struct pvr_device *device, struct pvr_bo *bo);
 
+#if defined(HAVE_VALGRIND)
+void *pvr_bo_cpu_map_unchanged(struct pvr_device *device,
+                               struct pvr_bo *pvr_bo);
+#else /* defined(HAVE_VALGRIND) */
+static ALWAYS_INLINE void *pvr_bo_cpu_map_unchanged(struct pvr_device *device,
+                                                    struct pvr_bo *pvr_bo)
+{
+   return pvr_bo_cpu_map(device, pvr_bo);
+}
+#endif /* defined(HAVE_VALGRIND) */
+
 #endif /* PVR_BO_H */

src/imagination/vulkan/winsys/pvr_winsys.h

@@ -121,6 +121,10 @@ struct pvr_winsys_bo {
    uint64_t size;
 
    bool is_imported;
+
+#if defined(HAVE_VALGRIND)
+   char *vbits;
+#endif /* defined(HAVE_VALGRIND) */
 };
 
 struct pvr_winsys_vma {