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Commit 8dfec614 authored by Andiry Xu's avatar Andiry Xu Committed by Sarah Sharp
Browse files

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: default avatarAndiry Xu <andiry.xu@amd.com>
Signed-off-by: default avatarSarah Sharp <sarah.a.sharp@linux.intel.com>
Tested-by: default avatarPaul Zimmerman <Paul.Zimmerman@synopsys.com>
parent 186a7ef1

drivers/usb/host/xhci-mem.c

+63 −12
Original line number Diff line number Diff line
@@ -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,
@@ -1361,16 +1422,6 @@ 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);

	if (!virt_dev->eps[ep_index].new_ring) {

drivers/usb/host/xhci-ring.c

+28 −5
Original line number Diff line number Diff line
@@ -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");



	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;

drivers/usb/host/xhci.h

+2 −0
Original line number Diff line number Diff line
@@ -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);