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authorSomnath Kotur <somnath.kotur@broadcom.com>2017-11-06 08:07:29 -0800
committerDoug Ledford <dledford@redhat.com>2017-11-13 15:53:57 -0500
commit9b40183c08e48f1d26d06d39f29808c9c6037561 (patch)
tree377a0f40b396d2b98a65ae0c2c7979527576b1bd /drivers/infiniband/hw/bnxt_re/qplib_rcfw.c
parent685894dd9bd03b92803fbc72565789713f067d4c (diff)
RDMA/bnxt_re: Add memory barriers when processing CQ/EQ entries
The code determines if the next ring entry is valid before proceeding further to read the rest of the entry. The CPU can re-order and read the rest of the entry first, possibly reading a stale entry, if DMA of a new entry happens right after reading it. Signed-off-by: Somnath Kotur <somnath.kotur@broadcom.com> Signed-off-by: Selvin Xavier <selvin.xavier@broadcom.com> Signed-off-by: Doug Ledford <dledford@redhat.com>
Diffstat (limited to 'drivers/infiniband/hw/bnxt_re/qplib_rcfw.c')
-rw-r--r--drivers/infiniband/hw/bnxt_re/qplib_rcfw.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/infiniband/hw/bnxt_re/qplib_rcfw.c b/drivers/infiniband/hw/bnxt_re/qplib_rcfw.c
index a7b5de3e193c..bb5574adf195 100644
--- a/drivers/infiniband/hw/bnxt_re/qplib_rcfw.c
+++ b/drivers/infiniband/hw/bnxt_re/qplib_rcfw.c
@@ -359,6 +359,10 @@ static void bnxt_qplib_service_creq(unsigned long data)
creqe = &creq_ptr[get_creq_pg(sw_cons)][get_creq_idx(sw_cons)];
if (!CREQ_CMP_VALID(creqe, raw_cons, creq->max_elements))
break;
+ /* The valid test of the entry must be done first before
+ * reading any further.
+ */
+ dma_rmb();
type = creqe->type & CREQ_BASE_TYPE_MASK;
switch (type) {