dma-buf attachment has only exporter private data, but importer private data
can be useful for importer especially to re-import the same dma-buf.
To use importer private data in attachment of the device, the function to
search attachment in the attachment list of dma-buf is also added.
Signed-off-by: Seung-Woo Kim <sw0312....@samsung.com>
---
drivers/base/dma-buf.c | 31 +++++++++++++++++++++++++++++++
include/linux/dma-buf.h | 4 ++++
2 files changed, 35 insertions(+), 0 deletions(-)
diff --git a/drivers/base/dma-buf.c b/drivers/base/dma-buf.c
index 08fe897..a1eaaf2 100644
--- a/drivers/base/dma-buf.c
+++ b/drivers/base/dma-buf.c
@@ -259,6 +259,37 @@ err_attach:
EXPORT_SYMBOL_GPL(dma_buf_attach);
/**
+ * dma_buf_get_attachment - Get attachment with the device from dma_buf's
+ * attachments list
+ * @dmabuf: [in] buffer to find device from.
+ * @dev: [in] device to be found.
+ *
+ * Returns struct dma_buf_attachment * attaching the device; may return
+ * negative error codes.
+ *
+ */
+struct dma_buf_attachment *dma_buf_get_attachment(struct dma_buf *dmabuf,
+ struct device *dev)
+{
+ struct dma_buf_attachment *attach;
+
+ if (WARN_ON(!dmabuf || !dev))
+ return ERR_PTR(-EINVAL);
+
+ mutex_lock(&dmabuf->lock);
+ list_for_each_entry(attach, &dmabuf->attachments, node) {
+ if (attach->dev == dev) {
+ mutex_unlock(&dmabuf->lock);
+ return attach;
+ }
+ }
+ mutex_unlock(&dmabuf->lock);
+
+ return ERR_PTR(-ENODEV);
+}
+EXPORT_SYMBOL_GPL(dma_buf_get_attachment);
+
+/**
* dma_buf_detach - Remove the given attachment from dmabuf's attachments list;
* optionally calls detach() of dma_buf_ops for device-specific detach
* @dmabuf: [in] buffer to detach from.
diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h
index dfac5ed..09cff0f 100644
--- a/include/linux/dma-buf.h
+++ b/include/linux/dma-buf.h
@@ -136,6 +136,7 @@ struct dma_buf {
* @dev: device attached to the buffer.
* @node: list of dma_buf_attachment.
* @priv: exporter specific attachment data.
+ * @importer_priv: importer specific attachment data.
*
* This structure holds the attachment information between the dma_buf buffer
* and its user device(s). The list contains one attachment struct per device
@@ -146,6 +147,7 @@ struct dma_buf_attachment {
struct device *dev;
struct list_head node;
void *priv;
+ void *importer_priv;
};
/**
@@ -164,6 +166,8 @@ static inline void get_dma_buf(struct dma_buf *dmabuf)
struct dma_buf_attachment *dma_buf_attach(struct dma_buf *dmabuf,
struct device *dev);
+struct dma_buf_attachment *dma_buf_get_attachment(struct dma_buf *dmabuf,
+ struct device *dev);
void dma_buf_detach(struct dma_buf *dmabuf,
struct dma_buf_attachment *dmabuf_attach);
--
1.7.4.1
--
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