Commit 84596451 authored by Scott Feldman's avatar Scott Feldman Committed by David S. Miller

enic: move wmb closer to where needed: before writing posted_index to hw

Signed-off-by: default avatarScott Feldman <scofeldm@cisco.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent cb3c7669
......@@ -58,8 +58,6 @@ static inline void enic_queue_wq_desc_ex(struct vnic_wq *wq,
(u16)vlan_tag,
0 /* loopback */);
wmb();
vnic_wq_post(wq, os_buf, dma_addr, len, sop, eop);
}
......@@ -127,8 +125,6 @@ static inline void enic_queue_rq_desc(struct vnic_rq *rq,
(u64)dma_addr | VNIC_PADDR_TARGET,
type, (u16)len);
wmb();
vnic_rq_post(rq, os_buf, os_buf_index, dma_addr, len);
}
......
......@@ -132,8 +132,15 @@ static inline void vnic_rq_post(struct vnic_rq *rq,
#define VNIC_RQ_RETURN_RATE 0xf /* keep 2^n - 1 */
#endif
if ((buf->index & VNIC_RQ_RETURN_RATE) == 0)
if ((buf->index & VNIC_RQ_RETURN_RATE) == 0) {
/* Adding write memory barrier prevents compiler and/or CPU
* reordering, thus avoiding descriptor posting before
* descriptor is initialized. Otherwise, hardware can read
* stale descriptor fields.
*/
wmb();
iowrite32(buf->index, &rq->ctrl->posted_index);
}
}
static inline void vnic_rq_return_descs(struct vnic_rq *rq, unsigned int count)
......
......@@ -108,8 +108,15 @@ static inline void vnic_wq_post(struct vnic_wq *wq,
buf->len = len;
buf = buf->next;
if (eop)
if (eop) {
/* Adding write memory barrier prevents compiler and/or CPU
* reordering, thus avoiding descriptor posting before
* descriptor is initialized. Otherwise, hardware can read
* stale descriptor fields.
*/
wmb();
iowrite32(buf->index, &wq->ctrl->posted_index);
}
wq->to_use = buf;
wq->ring.desc_avail--;
......
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