From: Haiyang Zhang Date: Sun, 11 Sep 2022 20:40:05 +0000 (-0700) Subject: net: mana: Add rmb after checking owner bits X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=71075d7d463281fd43cebf3a10170503a1c72995;p=linux.git net: mana: Add rmb after checking owner bits commit 6fd2c68da55c552f86e401ebe40c4a619025ef69 upstream. Per GDMA spec, rmb is necessary after checking owner_bits, before reading EQ or CQ entries. Add rmb in these two places to comply with the specs. Cc: stable@vger.kernel.org Fixes: ca9c54d2d6a5 ("net: mana: Add a driver for Microsoft Azure Network Adapter (MANA)") Reported-by: Sinan Kaya Signed-off-by: Haiyang Zhang Reviewed-by: Dexuan Cui Link: https://lore.kernel.org/r/1662928805-15861-1-git-send-email-haiyangz@microsoft.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/net/ethernet/microsoft/mana/gdma_main.c b/drivers/net/ethernet/microsoft/mana/gdma_main.c index cee75b561f59d..f577507f522b7 100644 --- a/drivers/net/ethernet/microsoft/mana/gdma_main.c +++ b/drivers/net/ethernet/microsoft/mana/gdma_main.c @@ -368,6 +368,11 @@ static void mana_gd_process_eq_events(void *arg) break; } + /* Per GDMA spec, rmb is necessary after checking owner_bits, before + * reading eqe. + */ + rmb(); + mana_gd_process_eqe(eq); eq->head++; @@ -1096,6 +1101,11 @@ static int mana_gd_read_cqe(struct gdma_queue *cq, struct gdma_comp *comp) if (WARN_ON_ONCE(owner_bits != new_bits)) return -1; + /* Per GDMA spec, rmb is necessary after checking owner_bits, before + * reading completion info + */ + rmb(); + comp->wq_num = cqe->cqe_info.wq_num; comp->is_sq = cqe->cqe_info.is_sq; memcpy(comp->cqe_data, cqe->cqe_data, GDMA_COMP_DATA_SIZE);