dma-buf: Add unlocked variant of vmapping functions

Add unlocked variant of dma_buf_vmap/vunmap() that will be utilized
by drivers that don't take the reservation lock explicitly.

Acked-by: Sumit Semwal <sumit.semwal@linaro.org>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221017172229.42269-2-dmitry.osipenko@collabora.com

diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
index efb4990..e95fc8d 100644 (file)
--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@@ -1426,6 +1426,33 @@ out_unlock:
 EXPORT_SYMBOL_NS_GPL(dma_buf_vmap, DMA_BUF);
 
 /**
+ * dma_buf_vmap_unlocked - Create virtual mapping for the buffer object into kernel
+ * address space. Same restrictions as for vmap and friends apply.
+ * @dmabuf:    [in]    buffer to vmap
+ * @map:       [out]   returns the vmap pointer
+ *
+ * Unlocked version of dma_buf_vmap()
+ *
+ * Returns 0 on success, or a negative errno code otherwise.
+ */
+int dma_buf_vmap_unlocked(struct dma_buf *dmabuf, struct iosys_map *map)
+{
+       int ret;
+
+       iosys_map_clear(map);
+
+       if (WARN_ON(!dmabuf))
+               return -EINVAL;
+
+       dma_resv_lock(dmabuf->resv, NULL);
+       ret = dma_buf_vmap(dmabuf, map);
+       dma_resv_unlock(dmabuf->resv);
+
+       return ret;
+}
+EXPORT_SYMBOL_NS_GPL(dma_buf_vmap_unlocked, DMA_BUF);
+
+/**
  * dma_buf_vunmap - Unmap a vmap obtained by dma_buf_vmap.
  * @dmabuf:    [in]    buffer to vunmap
  * @map:       [in]    vmap pointer to vunmap
@@ -1449,6 +1476,22 @@ void dma_buf_vunmap(struct dma_buf *dmabuf, struct iosys_map *map)
 }
 EXPORT_SYMBOL_NS_GPL(dma_buf_vunmap, DMA_BUF);
 
+/**
+ * dma_buf_vunmap_unlocked - Unmap a vmap obtained by dma_buf_vmap.
+ * @dmabuf:    [in]    buffer to vunmap
+ * @map:       [in]    vmap pointer to vunmap
+ */
+void dma_buf_vunmap_unlocked(struct dma_buf *dmabuf, struct iosys_map *map)
+{
+       if (WARN_ON(!dmabuf))
+               return;
+
+       dma_resv_lock(dmabuf->resv, NULL);
+       dma_buf_vunmap(dmabuf, map);
+       dma_resv_unlock(dmabuf->resv);
+}
+EXPORT_SYMBOL_NS_GPL(dma_buf_vunmap_unlocked, DMA_BUF);
+
 #ifdef CONFIG_DEBUG_FS
 static int dma_buf_debug_show(struct seq_file *s, void *unused)
 {

diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h
index 7173179..8daa054 100644 (file)
--- a/include/linux/dma-buf.h
+++ b/include/linux/dma-buf.h
@@ -632,4 +632,6 @@ int dma_buf_mmap(struct dma_buf *, struct vm_area_struct *,
                 unsigned long);
 int dma_buf_vmap(struct dma_buf *dmabuf, struct iosys_map *map);
 void dma_buf_vunmap(struct dma_buf *dmabuf, struct iosys_map *map);
+int dma_buf_vmap_unlocked(struct dma_buf *dmabuf, struct iosys_map *map);
+void dma_buf_vunmap_unlocked(struct dma_buf *dmabuf, struct iosys_map *map);
 #endif /* __DMA_BUF_H__ */