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@xxxxxxx>
---
drivers/usb/host/xhci-mem.c | 75 +++++++++++++++++++++++++++++++++++-------
drivers/usb/host/xhci-ring.c | 33 +++++++++++++++---
drivers/usb/host/xhci.h | 2 +
3 files changed, 93 insertions(+), 17 deletions(-)
diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index c1800c7..c37aa1b 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -119,6 +119,34 @@ static void xhci_link_segments(struct xhci_hcd *xhci, struct xhci_segment *prev,
}
}
+/*
+ * Link the ring to the new segments.
+ * Set Toggle Cycle for the new ring if needed.
+ */
+static void xhci_link_rings(struct xhci_hcd *xhci, struct xhci_ring *ring,
+ struct xhci_segment *first, struct xhci_segment *last,
+ unsigned int num_segs)
+{
+ struct xhci_segment *next;
+
+ if (!ring || !first || !last)
+ return;
+
+ next = ring->enq_seg->next;
+ xhci_link_segments(xhci, ring->enq_seg, first, ring->type);
+ xhci_link_segments(xhci, last, next, ring->type);
+ ring->num_segs += num_segs;
+ ring->num_trbs_free += (TRBS_PER_SEGMENT - 1) * num_segs;
+
+ if (ring->type != TYPE_EVENT && ring->enq_seg == ring->last_seg) {
+ ring->last_seg->trbs[TRBS_PER_SEGMENT-1].link.control
+ &= ~cpu_to_le32(LINK_TOGGLE);
+ last->trbs[TRBS_PER_SEGMENT-1].link.control
+ |= cpu_to_le32(LINK_TOGGLE);
+ ring->last_seg = last;
+ }
+}
+
/* XXX: Do we need the hcd structure in all these functions? */
void xhci_ring_free(struct xhci_hcd *xhci, struct xhci_ring *ring)
{
@@ -287,6 +315,39 @@ static void xhci_reinit_cached_ring(struct xhci_hcd *xhci,
INIT_LIST_HEAD(&ring->td_list);
}
+/*
+ * Expand an existing ring.
+ * Look for a cached ring or allocate a new ring which has same segment numbers
+ * and link the two rings.
+ */
+int xhci_ring_expansion(struct xhci_hcd *xhci, struct xhci_ring *ring,
+ unsigned int num_trbs, gfp_t flags)
+{
+ struct xhci_segment *first;
+ struct xhci_segment *last;
+ unsigned int num_segs;
+ unsigned int num_segs_needed;
+ int ret;
+
+ num_segs_needed = (num_trbs + (TRBS_PER_SEGMENT - 1) - 1) /
+ (TRBS_PER_SEGMENT - 1);
+
+ /* Allocate number of segments we needed, or double the ring size */
+ num_segs = ring->num_segs > num_segs_needed ?
+ ring->num_segs : num_segs_needed;
+
+ ret = xhci_alloc_segments_for_ring(xhci, &first, &last,
+ num_segs, ring->cycle_state, ring->type, flags);
+ if (ret)
+ return -ENOMEM;
+
+ xhci_link_rings(xhci, ring, first, last, num_segs);
+ xhci_dbg(xhci, "ring expansion succeed, now has %d segments\n",
+ ring->num_segs);
+
+ return 0;
+}
+
#define CTX_SIZE(_hcc) (HCC_64BYTE_CONTEXT(_hcc) ? 64 : 32)
static struct xhci_container_ctx *xhci_alloc_container_ctx(struct xhci_hcd *xhci,
@@ -1361,18 +1422,8 @@ int xhci_endpoint_init(struct xhci_hcd *xhci,
type = usb_endpoint_type(&ep->desc);
/* Set up the endpoint ring */
- /*
- * Isochronous endpoint ring needs bigger size because one isoc URB
- * carries multiple packets and it will insert multiple tds to the
- * ring.
- * This should be replaced with dynamic ring resizing in the future.
- */
- if (usb_endpoint_xfer_isoc(&ep->desc))
- virt_dev->eps[ep_index].new_ring =
- xhci_ring_alloc(xhci, 8, 1, type, mem_flags);
- else
- virt_dev->eps[ep_index].new_ring =
- xhci_ring_alloc(xhci, 1, 1, type, mem_flags);
+ virt_dev->eps[ep_index].new_ring =
+ xhci_ring_alloc(xhci, 1, 1, type, mem_flags);
if (!virt_dev->eps[ep_index].new_ring) {
/* Attempt to use the ring cache */
if (virt_dev->num_rings_cached == 0)
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index f9b6fa3..4194f34 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -2490,6 +2490,8 @@ static void queue_trb(struct xhci_hcd *xhci, struct xhci_ring *ring,
static int prepare_ring(struct xhci_hcd *xhci, struct xhci_ring *ep_ring,
u32 ep_state, unsigned int num_trbs, gfp_t mem_flags)
{
+ unsigned int num_trbs_needed;
+
/* Make sure the endpoint has been added to xHC schedule */
switch (ep_state) {
case EP_STATE_DISABLED:
@@ -2517,11 +2519,32 @@ static int prepare_ring(struct xhci_hcd *xhci, struct xhci_ring *ep_ring,
*/
return -EINVAL;
}
- if (!room_on_ring(xhci, ep_ring, num_trbs)) {
- /* FIXME allocate more room */
- xhci_err(xhci, "ERROR no room on ep ring\n");
- return -ENOMEM;
- }
+
+ while (1) {
+ if (room_on_ring(xhci, ep_ring, num_trbs))
+ break;
+
+ if (ep_ring == xhci->cmd_ring) {
+ xhci_err(xhci, "Do not support expand command ring\n");
+ return -ENOMEM;
+ }
+
+ if (ep_ring->enq_seg == ep_ring->deq_seg &&
+ ep_ring->dequeue > ep_ring->enqueue) {
+ xhci_err(xhci, "Can not expand the ring while dequeue "
+ "pointer has not passed the link TRB\n");
+ return -ENOMEM;
+ }
+
+ xhci_dbg(xhci, "ERROR no room on ep ring, "
+ "try ring expansion\n");
+ num_trbs_needed = num_trbs - ep_ring->num_trbs_free;
+ if (xhci_ring_expansion(xhci, ep_ring, num_trbs_needed,
+ mem_flags)) {
+ xhci_err(xhci, "Ring expansion failed\n");
+ return -ENOMEM;
+ }
+ };
if (enqueue_is_link_trb(ep_ring)) {
struct xhci_ring *ring = ep_ring;
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index cc98cce..6755143 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1625,6 +1625,8 @@ 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);
--
1.7.4.1
--
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