• [PATCH v3 15/19] thunderbolt: Add function to retrieve DMA device for t

    From Mika Westerberg@21:1/5 to All on Mon Oct 2 12:50:02 2017
    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>
    ---
    include/linux/thunderbolt.h | 13 +++++++++++++
    1 file changed, 13 insertions(+)

    diff --git a/include/linux/thunderbolt.h b/include/linux/thunderbolt.h
    index 36925e3aec7c..7b69853188b1 100644
    --- a/include/linux/thunderbolt.h
    +++ b/include/linux/thunderbolt.h
    @@ -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->d