This is a note to let you know that I've just added the patch titled
RDMA/irdma: Add missing read barriers
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
rdma-irdma-add-missing-read-barriers.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit f355453702b6b1dcb78f8ccfbde39c08f87f981f
Author: Shiraz Saleem <shiraz.saleem@xxxxxxxxx>
Date: Tue Jul 11 12:52:51 2023 -0500
RDMA/irdma: Add missing read barriers
[ Upstream commit 4984eb51453ff7eddee9e5ce816145be39c0ec5c ]
On code inspection, there are many instances in the driver where
CEQE and AEQE fields written to by HW are read without guaranteeing
that the polarity bit has been read and checked first.
Add a read barrier to avoid reordering of loads on the CEQE/AEQE fields
prior to checking the polarity bit.
Fixes: 3f49d6842569 ("RDMA/irdma: Implement HW Admin Queue OPs")
Signed-off-by: Shiraz Saleem <shiraz.saleem@xxxxxxxxx>
Link: https://lore.kernel.org/r/20230711175253.1289-2-shiraz.saleem@xxxxxxxxx
Signed-off-by: Leon Romanovsky <leon@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/infiniband/hw/irdma/ctrl.c b/drivers/infiniband/hw/irdma/ctrl.c
index a41e0d21143ae..d86d7ca9cee4a 100644
--- a/drivers/infiniband/hw/irdma/ctrl.c
+++ b/drivers/infiniband/hw/irdma/ctrl.c
@@ -3344,6 +3344,9 @@ int irdma_sc_ccq_get_cqe_info(struct irdma_sc_cq *ccq,
if (polarity != ccq->cq_uk.polarity)
return -ENOENT;
+ /* Ensure CEQE contents are read after valid bit is checked */
+ dma_rmb();
+
get_64bit_val(cqe, 8, &qp_ctx);
cqp = (struct irdma_sc_cqp *)(unsigned long)qp_ctx;
info->error = (bool)FIELD_GET(IRDMA_CQ_ERROR, temp);
@@ -3990,13 +3993,17 @@ int irdma_sc_get_next_aeqe(struct irdma_sc_aeq *aeq,
u8 polarity;
aeqe = IRDMA_GET_CURRENT_AEQ_ELEM(aeq);
- get_64bit_val(aeqe, 0, &compl_ctx);
get_64bit_val(aeqe, 8, &temp);
polarity = (u8)FIELD_GET(IRDMA_AEQE_VALID, temp);
if (aeq->polarity != polarity)
return -ENOENT;
+ /* Ensure AEQE contents are read after valid bit is checked */
+ dma_rmb();
+
+ get_64bit_val(aeqe, 0, &compl_ctx);
+
print_hex_dump_debug("WQE: AEQ_ENTRY WQE", DUMP_PREFIX_OFFSET, 16, 8,
aeqe, 16, false);
diff --git a/drivers/infiniband/hw/irdma/puda.c b/drivers/infiniband/hw/irdma/puda.c
index 4ec9639f1bdbf..562531712ea44 100644
--- a/drivers/infiniband/hw/irdma/puda.c
+++ b/drivers/infiniband/hw/irdma/puda.c
@@ -230,6 +230,9 @@ static int irdma_puda_poll_info(struct irdma_sc_cq *cq,
if (valid_bit != cq_uk->polarity)
return -ENOENT;
+ /* Ensure CQE contents are read after valid bit is checked */
+ dma_rmb();
+
if (cq->dev->hw_attrs.uk_attrs.hw_rev >= IRDMA_GEN_2)
ext_valid = (bool)FIELD_GET(IRDMA_CQ_EXTCQE, qword3);
@@ -243,6 +246,9 @@ static int irdma_puda_poll_info(struct irdma_sc_cq *cq,
if (polarity != cq_uk->polarity)
return -ENOENT;
+ /* Ensure ext CQE contents are read after ext valid bit is checked */
+ dma_rmb();
+
IRDMA_RING_MOVE_HEAD_NOCHECK(cq_uk->cq_ring);
if (!IRDMA_RING_CURRENT_HEAD(cq_uk->cq_ring))
cq_uk->polarity = !cq_uk->polarity;
diff --git a/drivers/infiniband/hw/irdma/uk.c b/drivers/infiniband/hw/irdma/uk.c
index dd428d915c175..ea2c07751245a 100644
--- a/drivers/infiniband/hw/irdma/uk.c
+++ b/drivers/infiniband/hw/irdma/uk.c
@@ -1527,6 +1527,9 @@ void irdma_uk_clean_cq(void *q, struct irdma_cq_uk *cq)
if (polarity != temp)
break;
+ /* Ensure CQE contents are read after valid bit is checked */
+ dma_rmb();
+
get_64bit_val(cqe, 8, &comp_ctx);
if ((void *)(unsigned long)comp_ctx == q)
set_64bit_val(cqe, 8, 0);
