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| author |   Somnath Kotur <somnath.kotur@broadcom.com> | 2017-11-06 08:07:29 -0800 |
|---|---|---|
| committer |   Doug Ledford <dledford@redhat.com> | 2017-11-13 15:53:57 -0500 |
| commit | 9b40183c08e48f1d26d06d39f29808c9c6037561 (patch) | |
| tree | 377a0f40b396d2b98a65ae0c2c7979527576b1bd /drivers/infiniband/hw/bnxt_re/qplib_rcfw.c | |
| parent | IB/hfi1: Handle initial value of 0 for CCTI setting (diff) | |
| download | linux-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_rcfw.c | 4 |
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) { |