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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
parentIB/hfi1: Handle initial value of 0 for CCTI setting (diff)
downloadlinux-dev-9b40183c08e48f1d26d06d39f29808c9c6037561.tar.xz
linux-dev-9b40183c08e48f1d26d06d39f29808c9c6037561.zip
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 '')
-rw-r--r--drivers/infiniband/hw/bnxt_re/qplib_fp.c21
-rw-r--r--drivers/infiniband/hw/bnxt_re/qplib_rcfw.c4
2 files changed, 25 insertions, 0 deletions
diff --git a/drivers/infiniband/hw/bnxt_re/qplib_fp.c b/drivers/infiniband/hw/bnxt_re/qplib_fp.c
index a82044dacce0..31ea9f43f7d3 100644
--- a/drivers/infiniband/hw/bnxt_re/qplib_fp.c
+++ b/drivers/infiniband/hw/bnxt_re/qplib_fp.c
@@ -292,6 +292,12 @@ static void bnxt_qplib_service_nq(unsigned long data)
if (!NQE_CMP_VALID(nqe, raw_cons, hwq->max_elements))
break;
+ /*
+ * The valid test of the entry must be done first before
+ * reading any further.
+ */
+ dma_rmb();
+
type = le16_to_cpu(nqe->info10_type) & NQ_BASE_TYPE_MASK;
switch (type) {
case NQ_BASE_TYPE_CQ_NOTIFICATION:
@@ -1113,6 +1119,11 @@ static void __clean_cq(struct bnxt_qplib_cq *cq, u64 qp)
hw_cqe = &hw_cqe_ptr[CQE_PG(i)][CQE_IDX(i)];
if (!CQE_CMP_VALID(hw_cqe, i, cq_hwq->max_elements))
continue;
+ /*
+ * The valid test of the entry must be done first before
+ * reading any further.
+ */
+ dma_rmb();
switch (hw_cqe->cqe_type_toggle & CQ_BASE_CQE_TYPE_MASK) {
case CQ_BASE_CQE_TYPE_REQ:
case CQ_BASE_CQE_TYPE_TERMINAL:
@@ -1896,6 +1907,11 @@ static int do_wa9060(struct bnxt_qplib_qp *qp, struct bnxt_qplib_cq *cq,
/* If the next hwcqe is VALID */
if (CQE_CMP_VALID(peek_hwcqe, peek_raw_cq_cons,
cq->hwq.max_elements)) {
+ /*
+ * The valid test of the entry must be done first before
+ * reading any further.
+ */
+ dma_rmb();
/* If the next hwcqe is a REQ */
if ((peek_hwcqe->cqe_type_toggle &
CQ_BASE_CQE_TYPE_MASK) ==
@@ -2440,6 +2456,11 @@ int bnxt_qplib_poll_cq(struct bnxt_qplib_cq *cq, struct bnxt_qplib_cqe *cqe,
if (!CQE_CMP_VALID(hw_cqe, raw_cons, cq->hwq.max_elements))
break;
+ /*
+ * The valid test of the entry must be done first before
+ * reading any further.
+ */
+ dma_rmb();
/* From the device's respective CQE format to qplib_wc*/
switch (hw_cqe->cqe_type_toggle & CQ_BASE_CQE_TYPE_MASK) {
case CQ_BASE_CQE_TYPE_REQ:
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) {