xHCI: factor out segments allocation and free function
Factor out the segments allocation and free part from ring allocation
and free routines since driver may call them directly when try to expand
a ring.
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>
diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index 212012c..47b7629 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -65,6 +65,20 @@
kfree(seg);
}
+static void xhci_free_segments_for_ring(struct xhci_hcd *xhci,
+ struct xhci_segment *first)
+{
+ struct xhci_segment *seg;
+
+ seg = first->next;
+ while (seg != first) {
+ struct xhci_segment *next = seg->next;
+ xhci_segment_free(xhci, seg);
+ seg = next;
+ }
+ xhci_segment_free(xhci, first);
+}
+
/*
* Make the prev segment point to the next segment.
*
@@ -101,22 +115,12 @@
/* XXX: Do we need the hcd structure in all these functions? */
void xhci_ring_free(struct xhci_hcd *xhci, struct xhci_ring *ring)
{
- struct xhci_segment *seg;
- struct xhci_segment *first_seg;
-
if (!ring)
return;
- if (ring->first_seg) {
- first_seg = ring->first_seg;
- seg = first_seg->next;
- while (seg != first_seg) {
- struct xhci_segment *next = seg->next;
- xhci_segment_free(xhci, seg);
- seg = next;
- }
- xhci_segment_free(xhci, first_seg);
- ring->first_seg = NULL;
- }
+
+ if (ring->first_seg)
+ xhci_free_segments_for_ring(xhci, ring->first_seg);
+
kfree(ring);
}
@@ -143,6 +147,38 @@
ring->num_trbs_free = ring->num_segs * (TRBS_PER_SEGMENT - 1) - 1;
}
+/* Allocate segments and link them for a ring */
+static int xhci_alloc_segments_for_ring(struct xhci_hcd *xhci,
+ struct xhci_segment **first, struct xhci_segment **last,
+ unsigned int num_segs, enum xhci_ring_type type, gfp_t flags)
+{
+ struct xhci_segment *prev;
+
+ prev = xhci_segment_alloc(xhci, flags);
+ if (!prev)
+ return -ENOMEM;
+ num_segs--;
+
+ *first = prev;
+ while (num_segs > 0) {
+ struct xhci_segment *next;
+
+ next = xhci_segment_alloc(xhci, flags);
+ if (!next) {
+ xhci_free_segments_for_ring(xhci, *first);
+ return -ENOMEM;
+ }
+ xhci_link_segments(xhci, prev, next, type);
+
+ prev = next;
+ num_segs--;
+ }
+ xhci_link_segments(xhci, prev, *first, type);
+ *last = prev;
+
+ return 0;
+}
+
/**
* Create a new ring with zero or more segments.
*
@@ -154,7 +190,7 @@
unsigned int num_segs, enum xhci_ring_type type, gfp_t flags)
{
struct xhci_ring *ring;
- struct xhci_segment *prev;
+ int ret;
ring = kzalloc(sizeof *(ring), flags);
if (!ring)
@@ -166,30 +202,15 @@
if (num_segs == 0)
return ring;
- ring->first_seg = xhci_segment_alloc(xhci, flags);
- if (!ring->first_seg)
+ ret = xhci_alloc_segments_for_ring(xhci, &ring->first_seg,
+ &ring->last_seg, num_segs, type, flags);
+ if (ret)
goto fail;
- num_segs--;
-
- prev = ring->first_seg;
- while (num_segs > 0) {
- struct xhci_segment *next;
-
- next = xhci_segment_alloc(xhci, flags);
- if (!next)
- goto fail;
- xhci_link_segments(xhci, prev, next, type);
-
- prev = next;
- num_segs--;
- }
- xhci_link_segments(xhci, prev, ring->first_seg, type);
- ring->last_seg = prev;
/* Only event ring does not use link TRB */
if (type != TYPE_EVENT) {
/* See section 4.9.2.1 and 6.4.4.1 */
- prev->trbs[TRBS_PER_SEGMENT-1].link.control |=
+ ring->last_seg->trbs[TRBS_PER_SEGMENT - 1].link.control |=
cpu_to_le32(LINK_TOGGLE);
}
xhci_initialize_ring_info(ring);