xHCI: dynamic ring expansion

If room_on_ring() check fails, try to expand the ring and check again.

When expand a ring, use a cached ring or allocate new segments, link
the original ring and the new ring or segments, update the original ring's
segment numbers and the last segment pointer.

Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Tested-by: Paul Zimmerman <Paul.Zimmerman@synopsys.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index ea8fc237d158..57cd632064b4 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1622,6 +1622,8 @@ 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);
+int xhci_ring_expansion(struct xhci_hcd *xhci, struct xhci_ring *ring,
+                                unsigned int num_trbs, gfp_t flags);
 void xhci_free_or_cache_endpoint_ring(struct xhci_hcd *xhci,
                 struct xhci_virt_device *virt_dev,
                 unsigned int ep_index);