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, 39 insertions, 6 deletions

diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 3106d22ae053..295a0a2063a6 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -804,7 +804,8 @@ int xhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb, gfp_t mem_flags)
         unsigned long flags;
         int ret = 0;
         unsigned int slot_id, ep_index;
-
+        struct urb_priv *urb_priv;
+        int size, i;
 
         if (!urb || xhci_check_args(hcd, urb->dev, urb->ep, true, __func__) <= 0)
                 return -EINVAL;
@@ -824,6 +825,30 @@ int xhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb, gfp_t mem_flags)
                 ret = -ESHUTDOWN;
                 goto exit;
         }
+
+        if (usb_endpoint_xfer_isoc(&urb->ep->desc))
+                size = urb->number_of_packets;
+        else
+                size = 1;
+
+        urb_priv = kzalloc(sizeof(struct urb_priv) +
+                                  size * sizeof(struct xhci_td *), mem_flags);
+        if (!urb_priv)
+                return -ENOMEM;
+
+        for (i = 0; i < size; i++) {
+                urb_priv->td[i] = kzalloc(sizeof(struct xhci_td), mem_flags);
+                if (!urb_priv->td[i]) {
+                        urb_priv->length = i;
+                        xhci_urb_free_priv(xhci, urb_priv);
+                        return -ENOMEM;
+                }
+        }
+
+        urb_priv->length = size;
+        urb_priv->td_cnt = 0;
+        urb->hcpriv = urb_priv;
+
         if (usb_endpoint_xfer_control(&urb->ep->desc)) {
                 /* Check to see if the max packet size for the default control
                  * endpoint changed during FS device enumeration
@@ -877,6 +902,8 @@ int xhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb, gfp_t mem_flags)
 exit:
         return ret;
 dying:
+        xhci_urb_free_priv(xhci, urb_priv);
+        urb->hcpriv = NULL;
         xhci_dbg(xhci, "Ep 0x%x: URB %p submitted for "
                         "non-responsive xHCI host.\n",
                         urb->ep->desc.bEndpointAddress, urb);
@@ -918,9 +945,10 @@ dying:
 int xhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
 {
         unsigned long flags;
-        int ret;
+        int ret, i;
         u32 temp;
         struct xhci_hcd *xhci;
+        struct urb_priv *urb_priv;
         struct xhci_td *td;
         unsigned int ep_index;
         struct xhci_ring *ep_ring;
@@ -935,12 +963,12 @@ int xhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
         temp = xhci_readl(xhci, &xhci->op_regs->status);
         if (temp == 0xffffffff) {
                 xhci_dbg(xhci, "HW died, freeing TD.\n");
-                td = (struct xhci_td *) urb->hcpriv;
+                urb_priv = urb->hcpriv;
 
                 usb_hcd_unlink_urb_from_ep(hcd, urb);
                 spin_unlock_irqrestore(&xhci->lock, flags);
                 usb_hcd_giveback_urb(xhci_to_hcd(xhci), urb, -ESHUTDOWN);
-                kfree(td);
+                xhci_urb_free_priv(xhci, urb_priv);
                 return ret;
         }
         if (xhci->xhc_state & XHCI_STATE_DYING) {
@@ -968,9 +996,14 @@ int xhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
 
         xhci_dbg(xhci, "Endpoint ring:\n");
         xhci_debug_ring(xhci, ep_ring);
-        td = (struct xhci_td *) urb->hcpriv;
 
-        list_add_tail(&td->cancelled_td_list, &ep->cancelled_td_list);
+        urb_priv = urb->hcpriv;
+
+        for (i = urb_priv->td_cnt; i < urb_priv->length; i++) {
+                td = urb_priv->td[i];
+                list_add_tail(&td->cancelled_td_list, &ep->cancelled_td_list);
+        }
+
         /* Queue a stop endpoint command, but only if this is
          * the first cancellation to be handled.
          */