USB: xHCI: Introduce urb_priv structure

Add urb_priv data structure to xHCI driver. This structure allows multiple
xhci TDs to be linked to one urb, which is essential for isochronous
transfer. For non-isochronous urb, only one TD is needed for one urb;
for isochronous urb, the TD number for the urb is equal to
urb->number_of_packets.

The length field of urb_priv indicates the number of TDs in the urb.
The td_cnt field indicates the number of TDs already processed by xHC.
When td_cnt matches length, the urb can be given back to usbcore.

When an urb is dequeued or cancelled, add all the unprocessed TDs to the
endpoint's cancelled_td_list. When process a cancelled TD, increase
td_cnt field. When td_cnt equals urb_priv->length, giveback the
cancelled urb.

Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 7 insertions, 0 deletions

diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index f4dfb26a65aa..ebf62082950b 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1090,6 +1090,12 @@ struct xhci_scratchpad {
         dma_addr_t *sp_dma_buffers;
 };
 
+struct urb_priv {
+        int     length;
+        int     td_cnt;
+        struct  xhci_td *td[0];
+};
+
 /*
  * Each segment table entry is 4*32bits long.  1K seems like an ok size:
  * (1K bytes * 8bytes/bit) / (4*32 bits) = 64 segment entries in the table,
@@ -1347,6 +1353,7 @@ struct xhci_ring *xhci_stream_id_to_ring(
 struct xhci_command *xhci_alloc_command(struct xhci_hcd *xhci,
                 bool allocate_in_ctx, bool allocate_completion,
                 gfp_t mem_flags);
+void xhci_urb_free_priv(struct xhci_hcd *xhci, struct urb_priv *urb_priv);
 void xhci_free_command(struct xhci_hcd *xhci,
                 struct xhci_command *command);