If room_on_ring() check fails, try to expand the ring and check again.
When expand a ring, try to find a ring with the same number of segments
in the cached ring; if not found, allocate a new ring with the same
cycle state and segment numbers. Link the two rings, update the old
ring's segment numbers and the last segment pointer.
When room_on_ring check fails, try ring expansion until the ring has
more than 256 segments.
Signed-off-by: Andiry Xu <andiry.xu@xxxxxxx>
---
drivers/usb/host/xhci-mem.c | 82 ++++++++++++++++++++++++++++++++++++++----
drivers/usb/host/xhci-ring.c | 38 ++++++++++++++------
drivers/usb/host/xhci.h | 3 ++
3 files changed, 105 insertions(+), 18 deletions(-)
diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index 018f825..10f9f91 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -115,6 +115,32 @@ static void xhci_link_segments(struct xhci_hcd *xhci, struct xhci_segment *prev,
(unsigned long long)next->dma);
}
+/*
+ * Link the prev ring to the next ring.
+ *
+ * Link the last link TRB of prev ring to the first segment of next ring;
+ * link the last link TRB of next ring to the first segment of prev ring;
+ * Clear Toggle Cycle for the prev ring.
+ */
+static void xhci_link_rings(struct xhci_hcd *xhci, struct xhci_ring *prev,
+ struct xhci_ring *next, bool link_trbs, bool isoc)
+{
+ if (!prev || !next)
+ return;
+
+ xhci_link_segments(xhci, prev->last_seg, next->first_seg,
+ link_trbs, isoc);
+ xhci_link_segments(xhci, next->last_seg, prev->first_seg,
+ link_trbs, isoc);
+ prev->num_segs += next->num_segs;
+
+ if (link_trbs) {
+ prev->last_seg->trbs[TRBS_PER_SEGMENT-1].link.control
+ &= ~cpu_to_le32(LINK_TOGGLE);
+ }
+ prev->last_seg = next->last_seg;
+}
+
/* XXX: Do we need the hcd structure in all these functions? */
void xhci_ring_free(struct xhci_hcd *xhci, struct xhci_ring *ring)
{
@@ -268,6 +294,54 @@ 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_virt_device *xdev,
+ struct xhci_ring *ring, bool link_trbs,
+ bool isoc, gfp_t flags)
+{
+ struct xhci_ring *new_ring = NULL;
+ int i, num;
+
+ /* Attempt to use the ring cache */
+ if (xdev && xdev->num_rings_cached > 0) {
+ num = xdev->num_rings_cached;
+ for (i = 0; i < num; i++) {
+ if (xdev->ring_cache[i]->num_segs == ring->num_segs) {
+ new_ring = xdev->ring_cache[i];
+ /* Use the last cached ring to fill the hole */
+ if (i < num - 1) {
+ xdev->ring_cache[i] =
+ xdev->ring_cache[num - 1];
+ }
+ xdev->ring_cache[num - 1] = NULL;
+ xdev->num_rings_cached--;
+ xhci_reinit_cached_ring(xhci, new_ring,
+ ring->cycle_state, isoc);
+ break;
+ }
+ }
+ }
+
+ if (!new_ring) {
+ new_ring = xhci_ring_alloc(xhci, ring->num_segs,
+ ring->cycle_state, link_trbs, isoc, flags);
+ if (!new_ring)
+ return -ENOMEM;
+ }
+
+ xhci_link_rings(xhci, ring, new_ring, link_trbs, isoc);
+ xhci_dbg(xhci, "ring expansion succeed, now has %d segments\n",
+ ring->num_segs);
+
+ /* We do not need the ring structure anymore */
+ kfree(new_ring);
+ 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,
@@ -1189,15 +1263,9 @@ int xhci_endpoint_init(struct xhci_hcd *xhci,
ep_ctx = xhci_get_ep_ctx(xhci, virt_dev->in_ctx, ep_index);
/* 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, true, true, mem_flags);
+ xhci_ring_alloc(xhci, 1, 1, true, true, mem_flags);
else
virt_dev->eps[ep_index].new_ring =
xhci_ring_alloc(xhci, 1, 1, true, false, mem_flags);
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 4a50247..ef02b80 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -2394,8 +2394,9 @@ static void queue_trb(struct xhci_hcd *xhci, struct xhci_ring *ring,
* Does various checks on the endpoint ring, and makes it ready to queue num_trbs.
* FIXME allocate segments if the ring is full.
*/
-static int prepare_ring(struct xhci_hcd *xhci, struct xhci_ring *ep_ring,
- u32 ep_state, unsigned int num_trbs, bool isoc, gfp_t mem_flags)
+static int prepare_ring(struct xhci_hcd *xhci, struct xhci_virt_device *xdev,
+ struct xhci_ring *ep_ring, u32 ep_state, unsigned int num_trbs,
+ bool isoc, gfp_t mem_flags)
{
/* Make sure the endpoint has been added to xHC schedule */
switch (ep_state) {
@@ -2424,11 +2425,25 @@ 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->num_segs >= 256) {
+ xhci_err(xhci, "ERROR no room on ring "
+ "after ring expansion\n");
+ return -ENOMEM;
+ }
+
+ xhci_dbg(xhci, "ERROR no room on ep ring, "
+ "try ring expansion\n");
+ if (xhci_ring_expansion(xhci, xdev, ep_ring, true,
+ isoc, mem_flags)) {
+ xhci_err(xhci, "Ring expansion failed\n");
+ return -ENOMEM;
+ }
+ };
if (enqueue_is_link_trb(ep_ring)) {
struct xhci_ring *ring = ep_ring;
@@ -2490,7 +2505,7 @@ static int prepare_transfer(struct xhci_hcd *xhci,
return -EINVAL;
}
- ret = prepare_ring(xhci, ep_ring,
+ ret = prepare_ring(xhci, xdev, ep_ring,
le32_to_cpu(ep_ctx->ep_info) & EP_STATE_MASK,
num_trbs, isoc, mem_flags);
if (ret)
@@ -3382,8 +3397,9 @@ int xhci_queue_isoc_tx_prepare(struct xhci_hcd *xhci, gfp_t mem_flags,
/* Check the ring to guarantee there is enough room for the whole urb.
* Do not insert any td of the urb to the ring if the check failed.
*/
- ret = prepare_ring(xhci, ep_ring, le32_to_cpu(ep_ctx->ep_info) & EP_STATE_MASK,
- num_trbs, true, mem_flags);
+ ret = prepare_ring(xhci, xdev, ep_ring,
+ le32_to_cpu(ep_ctx->ep_info) & EP_STATE_MASK,
+ num_trbs, true, mem_flags);
if (ret)
return ret;
@@ -3441,7 +3457,7 @@ static int queue_command(struct xhci_hcd *xhci, u32 field1, u32 field2,
if (!command_must_succeed)
reserved_trbs++;
- ret = prepare_ring(xhci, xhci->cmd_ring, EP_STATE_RUNNING,
+ ret = prepare_ring(xhci, NULL, xhci->cmd_ring, EP_STATE_RUNNING,
reserved_trbs, false, GFP_ATOMIC);
if (ret < 0) {
xhci_err(xhci, "ERR: No room for command on command ring\n");
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index df7407e..340764c 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1471,6 +1471,9 @@ 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);
+int xhci_ring_expansion(struct xhci_hcd *xhci, struct xhci_virt_device *xdev,
+ struct xhci_ring *ring, bool link_trbs,
+ bool isoc, 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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