thunderbolt: Add function to retrieve DMA device for the ring

This is needed when Thunderbolt service drivers need to DMA map memory
before it is passed down to the ring.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Michael Jamet <michael.jamet@intel.com>
Reviewed-by: Yehezkel Bernat <yehezkel.bernat@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Mika Westerberg 2017-10-02 13:38:42 +03:00 коммит произвёл David S. Miller
Родитель 4ffe722eef
Коммит 3304559e35
1 изменённых файлов: 13 добавлений и 0 удалений

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@ -19,6 +19,7 @@
#include <linux/list.h>
#include <linux/mutex.h>
#include <linux/mod_devicetable.h>
#include <linux/pci.h>
#include <linux/uuid.h>
#include <linux/workqueue.h>
@ -582,4 +583,16 @@ static inline int tb_ring_tx(struct tb_ring *ring, struct ring_frame *frame)
struct ring_frame *tb_ring_poll(struct tb_ring *ring);
void tb_ring_poll_complete(struct tb_ring *ring);
/**
* tb_ring_dma_device() - Return device used for DMA mapping
* @ring: Ring whose DMA device is retrieved
*
* Use this function when you are mapping DMA for buffers that are
* passed to the ring for sending/receiving.
*/
static inline struct device *tb_ring_dma_device(struct tb_ring *ring)
{
return &ring->nhi->pdev->dev;
}
#endif /* THUNDERBOLT_H_ */