Break the assumption that link-trbs are always located at the end of a
segment. Introduce ->link to struct xhci_segment and use that every
place that looks up the link-trb for a segment. This is meant to be
functionally equivalent to the existing driver and is just a search and
replace for hard coded "link at the end" assumption.
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
---
drivers/usb/host/xhci-mem.c | 17 +++++++----------
drivers/usb/host/xhci-ring.c | 7 ++-----
drivers/usb/host/xhci.c | 12 ++++++++----
drivers/usb/host/xhci.h | 1 +
4 files changed, 18 insertions(+), 19 deletions(-)
diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index 1d05dc9e1928..1eda6166b30f 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -115,11 +115,11 @@ static void xhci_link_segments(struct xhci_hcd *xhci, struct xhci_segment *prev,
return;
prev->next = next;
if (type != TYPE_EVENT) {
- prev->trbs[TRBS_PER_SEGMENT-1].link.segment_ptr =
- cpu_to_le64(next->dma);
+ prev->link = &prev->trbs[TRBS_PER_SEGMENT-1];
+ prev->link->link.segment_ptr = cpu_to_le64(next->dma);
/* Set the last TRB in the segment to have a TRB type ID of Link TRB */
- val = le32_to_cpu(prev->trbs[TRBS_PER_SEGMENT-1].link.control);
+ val = le32_to_cpu(prev->link->link.control);
val &= ~TRB_TYPE_BITMASK;
val |= TRB_TYPE(TRB_LINK);
/* Always set the chain bit with 0.95 hardware */
@@ -128,7 +128,7 @@ static void xhci_link_segments(struct xhci_hcd *xhci, struct xhci_segment *prev,
(type == TYPE_ISOC &&
(xhci->quirks & XHCI_AMD_0x96_HOST)))
val |= TRB_CHAIN;
- prev->trbs[TRBS_PER_SEGMENT-1].link.control = cpu_to_le32(val);
+ prev->link->link.control = cpu_to_le32(val);
}
}
@@ -152,10 +152,8 @@ static void xhci_link_rings(struct xhci_hcd *xhci, struct xhci_ring *ring,
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->link->link.control &= ~cpu_to_le32(LINK_TOGGLE);
+ last->link->link.control |= cpu_to_le32(LINK_TOGGLE);
ring->last_seg = last;
}
}
@@ -395,8 +393,7 @@ static struct xhci_ring *xhci_ring_alloc(struct xhci_hcd *xhci,
/* Only event ring does not use link TRB */
if (type != TYPE_EVENT) {
/* See section 4.9.2.1 and 6.4.4.1 */
- ring->last_seg->trbs[TRBS_PER_SEGMENT - 1].link.control |=
- cpu_to_le32(LINK_TOGGLE);
+ ring->last_seg->link->link.control |= cpu_to_le32(LINK_TOGGLE);
}
xhci_initialize_ring_info(ring, cycle_state);
return ring;
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 0efbbf0b6233..ae436cb7e06d 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -374,12 +374,10 @@ static struct xhci_segment *find_trb_seg(
union xhci_trb *trb, int *cycle_state)
{
struct xhci_segment *cur_seg = start_seg;
- struct xhci_generic_trb *generic_trb;
while (cur_seg->trbs > trb ||
&cur_seg->trbs[TRBS_PER_SEGMENT - 1] < trb) {
- generic_trb = &cur_seg->trbs[TRBS_PER_SEGMENT - 1].generic;
- if (generic_trb->field[3] & cpu_to_le32(LINK_TOGGLE))
+ if (cur_seg->link->link.control & cpu_to_le32(LINK_TOGGLE))
*cycle_state ^= 0x1;
cur_seg = cur_seg->next;
if (cur_seg == start_seg)
@@ -1735,8 +1733,7 @@ struct xhci_segment *trb_in_td(struct xhci_segment *start_seg,
if (start_dma == 0)
return NULL;
/* We may get an event for a Link TRB in the middle of a TD */
- end_seg_dma = xhci_trb_virt_to_dma(cur_seg,
- &cur_seg->trbs[TRBS_PER_SEGMENT - 1]);
+ end_seg_dma = xhci_trb_virt_to_dma(cur_seg, cur_seg->link);
/* If the end TRB isn't in this segment, this is set to 0 */
end_trb_dma = xhci_trb_virt_to_dma(cur_seg, end_trb);
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 1d3dc014b477..0b05f67fde5b 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -820,10 +820,14 @@ static void xhci_clear_command_ring(struct xhci_hcd *xhci)
ring = xhci->cmd_ring;
seg = ring->deq_seg;
do {
- memset(seg->trbs, 0,
- sizeof(union xhci_trb) * (TRBS_PER_SEGMENT - 1));
- seg->trbs[TRBS_PER_SEGMENT - 1].link.control &=
- cpu_to_le32(~TRB_CYCLE);
+ /* clear all but the link-trb */
+ memset(seg->trbs, 0, (seg->link - seg->trbs)
+ * sizeof(union xhci_trb));
+ /* note: 0-length memset if the link is at the end */
+ memset(seg->link + 1, 0, (TRBS_PER_SEGMENT
+ - (seg->link - seg->trbs) - 1)
+ * sizeof(union xhci_trb));
+ seg->link->link.control &= cpu_to_le32(~TRB_CYCLE);
seg = seg->next;
} while (seg != ring->deq_seg);
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 1a60e8498a55..35345b32509d 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1279,6 +1279,7 @@ union xhci_trb {
struct xhci_segment {
union xhci_trb *trbs;
/* private to HCD */
+ union xhci_trb *link;
struct xhci_segment *next;
dma_addr_t dma;
struct device *dev;
--
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