USB: xhci: Refactor code to free or cache endpoint rings.

Refactor out the code to cache or free endpoint rings from recently
dropped or disabled endpoints.  This code will be used by a new function
to reset a device and disable all endpoints except control endpoint 0.

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

drivers/usb/host/xhci-hcd.c

@@ -1266,30 +1266,13 @@ int xhci_check_bandwidth(struct usb_hcd *hcd, struct usb_device *udev)
 	xhci_zero_in_ctx(xhci, virt_dev);
 	/* Install new rings and free or cache any old rings */
 	for (i = 1; i < 31; ++i) {
-		int rings_cached;
-
 		if (!virt_dev->eps[i].new_ring)
 			continue;
 		/* Only cache or free the old ring if it exists.
 		 * It may not if this is the first add of an endpoint.
 		 */
 		if (virt_dev->eps[i].ring) {
-			rings_cached = virt_dev->num_rings_cached;
-			if (rings_cached < XHCI_MAX_RINGS_CACHED) {
-				virt_dev->num_rings_cached++;
-				rings_cached = virt_dev->num_rings_cached;
-				virt_dev->ring_cache[rings_cached] =
-					virt_dev->eps[i].ring;
-				xhci_dbg(xhci, "Cached old ring, "
-						"%d ring%s cached\n",
-						rings_cached,
-						(rings_cached > 1) ? "s" : "");
-			} else {
-				xhci_ring_free(xhci, virt_dev->eps[i].ring);
-				xhci_dbg(xhci, "Ring cache full (%d rings), "
-						"freeing ring\n",
-						virt_dev->num_rings_cached);
-			}
+			xhci_free_or_cache_endpoint_ring(xhci, virt_dev, i);
 		}
 		virt_dev->eps[i].ring = virt_dev->eps[i].new_ring;
 		virt_dev->eps[i].new_ring = NULL;

drivers/usb/host/xhci-mem.c

@@ -198,6 +198,31 @@ static struct xhci_ring *xhci_ring_alloc(struct xhci_hcd *xhci,
 	return 0;
 }
 
+void xhci_free_or_cache_endpoint_ring(struct xhci_hcd *xhci,
+		struct xhci_virt_device *virt_dev,
+		unsigned int ep_index)
+{
+	int rings_cached;
+
+	rings_cached = virt_dev->num_rings_cached;
+	if (rings_cached < XHCI_MAX_RINGS_CACHED) {
+		virt_dev->num_rings_cached++;
+		rings_cached = virt_dev->num_rings_cached;
+		virt_dev->ring_cache[rings_cached] =
+			virt_dev->eps[ep_index].ring;
+		xhci_dbg(xhci, "Cached old ring, "
+				"%d ring%s cached\n",
+				rings_cached,
+				(rings_cached > 1) ? "s" : "");
+	} else {
+		xhci_ring_free(xhci, virt_dev->eps[ep_index].ring);
+		xhci_dbg(xhci, "Ring cache full (%d rings), "
+				"freeing ring\n",
+				virt_dev->num_rings_cached);
+	}
+	virt_dev->eps[ep_index].ring = NULL;
+}
+
 /* Zero an endpoint ring (except for link TRBs) and move the enqueue and dequeue
  * pointers to the beginning of the ring.
  */

drivers/usb/host/xhci.h

@@ -1233,6 +1233,9 @@ int xhci_endpoint_init(struct xhci_hcd *xhci, struct xhci_virt_device *virt_dev,
 		struct usb_device *udev, struct usb_host_endpoint *ep,
 		gfp_t mem_flags);
 void xhci_ring_free(struct xhci_hcd *xhci, struct xhci_ring *ring);
+void xhci_free_or_cache_endpoint_ring(struct xhci_hcd *xhci,
+		struct xhci_virt_device *virt_dev,
+		unsigned int ep_index);
 struct xhci_command *xhci_alloc_command(struct xhci_hcd *xhci,
 		bool allocate_completion, gfp_t mem_flags);
 void xhci_free_command(struct xhci_hcd *xhci,