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-rw-r--r--include/linux/dmaengine.h43
1 files changed, 25 insertions, 18 deletions
diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index 272010a6078..c94d8f1d62e 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -44,7 +44,7 @@ enum dma_event {
};
/**
- * typedef dma_cookie_t
+ * typedef dma_cookie_t - an opaque DMA cookie
*
* if dma_cookie_t is >0 it's a DMA request cookie, <0 it's an error code
*/
@@ -80,14 +80,14 @@ struct dma_chan_percpu {
/**
* struct dma_chan - devices supply DMA channels, clients use them
- * @client: ptr to the client user of this chan, will be NULL when unused
- * @device: ptr to the dma device who supplies this channel, always !NULL
+ * @client: ptr to the client user of this chan, will be %NULL when unused
+ * @device: ptr to the dma device who supplies this channel, always !%NULL
* @cookie: last cookie value returned to client
- * @chan_id:
- * @class_dev:
+ * @chan_id: channel ID for sysfs
+ * @class_dev: class device for sysfs
* @refcount: kref, used in "bigref" slow-mode
- * @slow_ref:
- * @rcu:
+ * @slow_ref: indicates that the DMA channel is free
+ * @rcu: the DMA channel's RCU head
* @client_node: used to add this to the client chan list
* @device_node: used to add this to the device chan list
* @local: per-cpu pointer to a struct dma_chan_percpu
@@ -162,10 +162,17 @@ struct dma_client {
* @chancnt: how many DMA channels are supported
* @channels: the list of struct dma_chan
* @global_node: list_head for global dma_device_list
- * @refcount:
- * @done:
- * @dev_id:
- * Other func ptrs: used to make use of this device's capabilities
+ * @refcount: reference count
+ * @done: IO completion struct
+ * @dev_id: unique device ID
+ * @device_alloc_chan_resources: allocate resources and return the
+ * number of allocated descriptors
+ * @device_free_chan_resources: release DMA channel's resources
+ * @device_memcpy_buf_to_buf: memcpy buf pointer to buf pointer
+ * @device_memcpy_buf_to_pg: memcpy buf pointer to struct page
+ * @device_memcpy_pg_to_pg: memcpy struct page/offset to struct page/offset
+ * @device_memcpy_complete: poll the status of an IOAT DMA transaction
+ * @device_memcpy_issue_pending: push appended descriptors to hardware
*/
struct dma_device {
@@ -211,7 +218,7 @@ void dma_async_client_chan_request(struct dma_client *client,
* Both @dest and @src must be mappable to a bus address according to the
* DMA mapping API rules for streaming mappings.
* Both @dest and @src must stay memory resident (kernel memory or locked
- * user space pages)
+ * user space pages).
*/
static inline dma_cookie_t dma_async_memcpy_buf_to_buf(struct dma_chan *chan,
void *dest, void *src, size_t len)
@@ -225,7 +232,7 @@ static inline dma_cookie_t dma_async_memcpy_buf_to_buf(struct dma_chan *chan,
}
/**
- * dma_async_memcpy_buf_to_pg - offloaded copy
+ * dma_async_memcpy_buf_to_pg - offloaded copy from address to page
* @chan: DMA channel to offload copy to
* @page: destination page
* @offset: offset in page to copy to
@@ -250,18 +257,18 @@ static inline dma_cookie_t dma_async_memcpy_buf_to_pg(struct dma_chan *chan,
}
/**
- * dma_async_memcpy_buf_to_pg - offloaded copy
+ * dma_async_memcpy_pg_to_pg - offloaded copy from page to page
* @chan: DMA channel to offload copy to
- * @dest_page: destination page
+ * @dest_pg: destination page
* @dest_off: offset in page to copy to
- * @src_page: source page
+ * @src_pg: source page
* @src_off: offset in page to copy from
* @len: length
*
* Both @dest_page/@dest_off and @src_page/@src_off must be mappable to a bus
* address according to the DMA mapping API rules for streaming mappings.
* Both @dest_page/@dest_off and @src_page/@src_off must stay memory resident
- * (kernel memory or locked user space pages)
+ * (kernel memory or locked user space pages).
*/
static inline dma_cookie_t dma_async_memcpy_pg_to_pg(struct dma_chan *chan,
struct page *dest_pg, unsigned int dest_off, struct page *src_pg,
@@ -278,7 +285,7 @@ static inline dma_cookie_t dma_async_memcpy_pg_to_pg(struct dma_chan *chan,
/**
* dma_async_memcpy_issue_pending - flush pending copies to HW
- * @chan:
+ * @chan: target DMA channel
*
* This allows drivers to push copies to HW in batches,
* reducing MMIO writes where possible.