Merge tag '5.5-rc-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6

[linux.git] / include / linux / dma-buf.h

diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h
index ec212cb27fdc6c49e3a0ad1859eea6317c65c35e..af73f835c51c4db8f888a04346f360cc72c516c1 100644 (file)
--- a/include/linux/dma-buf.h
+++ b/include/linux/dma-buf.h
@@ -42,6 +42,18 @@ struct dma_buf_ops {
          */
        bool cache_sgt_mapping;
 
+       /**
+        * @dynamic_mapping:
+        *
+        * If true the framework makes sure that the map/unmap_dma_buf
+        * callbacks are always called with the dma_resv object locked.
+        *
+        * If false the framework makes sure that the map/unmap_dma_buf
+        * callbacks are always called without the dma_resv object locked.
+        * Mutual exclusive with @cache_sgt_mapping.
+        */
+       bool dynamic_mapping;
+
        /**
         * @attach:
         *
@@ -109,6 +121,9 @@ struct dma_buf_ops {
         * any other kind of sharing that the exporter might wish to make
         * available to buffer-users.
         *
+        * This is always called with the dmabuf->resv object locked when
+        * the dynamic_mapping flag is true.
+        *
         * Returns:
         *
         * A &sg_table scatter list of or the backing storage of the DMA buffer,
@@ -267,14 +282,16 @@ struct dma_buf_ops {
  * struct dma_buf - shared buffer object
  * @size: size of the buffer
  * @file: file pointer used for sharing buffers across, and for refcounting.
- * @attachments: list of dma_buf_attachment that denotes all devices attached.
+ * @attachments: list of dma_buf_attachment that denotes all devices attached,
+ *               protected by dma_resv lock.
  * @ops: dma_buf_ops associated with this buffer object.
  * @lock: used internally to serialize list manipulation, attach/detach and
- *        vmap/unmap, and accesses to name
+ *        vmap/unmap
  * @vmapping_counter: used internally to refcnt the vmaps
  * @vmap_ptr: the current vmap ptr if vmapping_counter > 0
  * @exp_name: name of the exporter; useful for debugging.
- * @name: userspace-provided name; useful for accounting and debugging.
+ * @name: userspace-provided name; useful for accounting and debugging,
+ *        protected by @resv.
  * @owner: pointer to exporter module; used for refcounting when exporter is a
  *         kernel module.
  * @list_node: node for dma_buf accounting and debugging.
@@ -323,10 +340,12 @@ struct dma_buf {
  * struct dma_buf_attachment - holds device-buffer attachment data
  * @dmabuf: buffer for this attachment.
  * @dev: device attached to the buffer.
- * @node: list of dma_buf_attachment.
+ * @node: list of dma_buf_attachment, protected by dma_resv lock of the dmabuf.
  * @sgt: cached mapping.
  * @dir: direction of cached mapping.
  * @priv: exporter specific attachment data.
+ * @dynamic_mapping: true if dma_buf_map/unmap_attachment() is called with the
+ * dma_resv lock held.
  *
  * This structure holds the attachment information between the dma_buf buffer
  * and its user device(s). The list contains one attachment struct per device
@@ -343,6 +362,7 @@ struct dma_buf_attachment {
        struct list_head node;
        struct sg_table *sgt;
        enum dma_data_direction dir;
+       bool dynamic_mapping;
        void *priv;
 };
 
@@ -394,10 +414,40 @@ static inline void get_dma_buf(struct dma_buf *dmabuf)
        get_file(dmabuf->file);
 }
 
+/**
+ * dma_buf_is_dynamic - check if a DMA-buf uses dynamic mappings.
+ * @dmabuf: the DMA-buf to check
+ *
+ * Returns true if a DMA-buf exporter wants to be called with the dma_resv
+ * locked for the map/unmap callbacks, false if it doesn't wants to be called
+ * with the lock held.
+ */
+static inline bool dma_buf_is_dynamic(struct dma_buf *dmabuf)
+{
+       return dmabuf->ops->dynamic_mapping;
+}
+
+/**
+ * dma_buf_attachment_is_dynamic - check if a DMA-buf attachment uses dynamic
+ * mappinsg
+ * @attach: the DMA-buf attachment to check
+ *
+ * Returns true if a DMA-buf importer wants to call the map/unmap functions with
+ * the dma_resv lock held.
+ */
+static inline bool
+dma_buf_attachment_is_dynamic(struct dma_buf_attachment *attach)
+{
+       return attach->dynamic_mapping;
+}
+
 struct dma_buf_attachment *dma_buf_attach(struct dma_buf *dmabuf,
-                                                       struct device *dev);
+                                         struct device *dev);
+struct dma_buf_attachment *
+dma_buf_dynamic_attach(struct dma_buf *dmabuf, struct device *dev,
+                      bool dynamic_mapping);
 void dma_buf_detach(struct dma_buf *dmabuf,
-                               struct dma_buf_attachment *dmabuf_attach);
+                   struct dma_buf_attachment *attach);
 
 struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info);
 
@@ -409,6 +459,7 @@ struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *,
                                        enum dma_data_direction);
 void dma_buf_unmap_attachment(struct dma_buf_attachment *, struct sg_table *,
                                enum dma_data_direction);
+void dma_buf_move_notify(struct dma_buf *dma_buf);
 int dma_buf_begin_cpu_access(struct dma_buf *dma_buf,
                             enum dma_data_direction dir);
 int dma_buf_end_cpu_access(struct dma_buf *dma_buf,