drm/vboxvideo: Use drm_gem_vram_vmap() interfaces

VRAM helpers support ref counting for pin and vmap operations, no need
to avoid these operations by employing the internal kmap interface. Just
use drm_gem_vram_vmap() and let it handle the details.

Also unexport the kmap interfaces from VRAM helpers. Vboxvideo was the
last user of these internal functions.

v2:
	* fixed a comma in commit description

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Tested-by: Hans de Goede <hdegoede@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200911075922.19317-1-tzimmermann@suse.de

drivers/gpu/drm/drm_gem_vram_helper.c

@@ -97,8 +97,8 @@ static const struct drm_gem_object_funcs drm_gem_vram_object_funcs;
  * hardware's draing engine.
  *
  * To access a buffer object's memory from the DRM driver, call
- * drm_gem_vram_kmap(). It (optionally) maps the buffer into kernel address
+ * drm_gem_vram_vmap(). It maps the buffer into kernel address
- * space and returns the memory address. Use drm_gem_vram_kunmap() to
+ * space and returns the memory address. Use drm_gem_vram_vunmap() to
  * release the mapping.
  */
 
@@ -437,39 +437,6 @@ out:
 	return kmap->virtual;
 }
 
-/**
- * drm_gem_vram_kmap() - Maps a GEM VRAM object into kernel address space
- * @gbo:	the GEM VRAM object
- * @map:	establish a mapping if necessary
- * @is_iomem:	returns true if the mapped memory is I/O memory, or false \
-	otherwise; can be NULL
- *
- * This function maps the buffer object into the kernel's address space
- * or returns the current mapping. If the parameter map is false, the
- * function only queries the current mapping, but does not establish a
- * new one.
- *
- * Returns:
- * The buffers virtual address if mapped, or
- * NULL if not mapped, or
- * an ERR_PTR()-encoded error code otherwise.
- */
-void *drm_gem_vram_kmap(struct drm_gem_vram_object *gbo, bool map,
-			bool *is_iomem)
-{
-	int ret;
-	void *virtual;
-
-	ret = ttm_bo_reserve(&gbo->bo, true, false, NULL);
-	if (ret)
-		return ERR_PTR(ret);
-	virtual = drm_gem_vram_kmap_locked(gbo, map, is_iomem);
-	ttm_bo_unreserve(&gbo->bo);
-
-	return virtual;
-}
-EXPORT_SYMBOL(drm_gem_vram_kmap);
-
 static void drm_gem_vram_kunmap_locked(struct drm_gem_vram_object *gbo)
 {
 	if (WARN_ON_ONCE(!gbo->kmap_use_count))
@@ -485,22 +452,6 @@ static void drm_gem_vram_kunmap_locked(struct drm_gem_vram_object *gbo)
 	 */
 }
 
-/**
- * drm_gem_vram_kunmap() - Unmaps a GEM VRAM object
- * @gbo:	the GEM VRAM object
- */
-void drm_gem_vram_kunmap(struct drm_gem_vram_object *gbo)
-{
-	int ret;
-
-	ret = ttm_bo_reserve(&gbo->bo, false, false, NULL);
-	if (WARN_ONCE(ret, "ttm_bo_reserve_failed(): ret=%d\n", ret))
-		return;
-	drm_gem_vram_kunmap_locked(gbo);
-	ttm_bo_unreserve(&gbo->bo);
-}
-EXPORT_SYMBOL(drm_gem_vram_kunmap);
-
 /**
  * drm_gem_vram_vmap() - Pins and maps a GEM VRAM object into kernel address
  *                       space
@@ -512,9 +463,6 @@ EXPORT_SYMBOL(drm_gem_vram_kunmap);
  * permanently. Call drm_gem_vram_vunmap() with the returned address to
  * unmap and unpin the GEM VRAM object.
  *
- * If you have special requirements for the pinning or mapping operations,
- * call drm_gem_vram_pin() and drm_gem_vram_kmap() directly.
- *
  * Returns:
  * The buffer's virtual address on success, or
  * an ERR_PTR()-encoded error code otherwise.

drivers/gpu/drm/vboxvideo/vbox_mode.c

@@ -397,11 +397,13 @@ static void vbox_cursor_atomic_update(struct drm_plane *plane,
 
 	vbox_crtc->cursor_enabled = true;
 
-	/* pinning is done in prepare/cleanup framebuffer */
+	src = drm_gem_vram_vmap(gbo);
-	src = drm_gem_vram_kmap(gbo, true, NULL);
 	if (IS_ERR(src)) {
+		/*
+		 * BUG: we should have pinned the BO in prepare_fb().
+		 */
 		mutex_unlock(&vbox->hw_mutex);
-		DRM_WARN("Could not kmap cursor bo, skipping update\n");
+		DRM_WARN("Could not map cursor bo, skipping update\n");
 		return;
 	}
 
@@ -414,7 +416,7 @@ static void vbox_cursor_atomic_update(struct drm_plane *plane,
 	data_size = width * height * 4 + mask_size;
 
 	copy_cursor_image(src, vbox->cursor_data, width, height, mask_size);
-	drm_gem_vram_kunmap(gbo);
+	drm_gem_vram_vunmap(gbo, src);
 
 	flags = VBOX_MOUSE_POINTER_VISIBLE | VBOX_MOUSE_POINTER_SHAPE |
 		VBOX_MOUSE_POINTER_ALPHA;

include/drm/drm_gem_vram_helper.h

@@ -100,9 +100,6 @@ u64 drm_gem_vram_mmap_offset(struct drm_gem_vram_object *gbo);
 s64 drm_gem_vram_offset(struct drm_gem_vram_object *gbo);
 int drm_gem_vram_pin(struct drm_gem_vram_object *gbo, unsigned long pl_flag);
 int drm_gem_vram_unpin(struct drm_gem_vram_object *gbo);
-void *drm_gem_vram_kmap(struct drm_gem_vram_object *gbo, bool map,
-			bool *is_iomem);
-void drm_gem_vram_kunmap(struct drm_gem_vram_object *gbo);
 void *drm_gem_vram_vmap(struct drm_gem_vram_object *gbo);
 void drm_gem_vram_vunmap(struct drm_gem_vram_object *gbo, void *vaddr);