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.kim@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);