diff options
| author |   Sinan Kaya <okaya@codeaurora.org> | 2018-03-25 10:39:20 -0400 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2018-03-26 12:47:56 -0400 |
| commit | fd141fa47c03018aa1f77c335b0f444493e145d5 (patch) | |
| tree | 5415abb0dde7f4757078fe748387d992c2ab5203 /drivers/net/ethernet/broadcom/bnxt | |
| parent | net: qlge: Eliminate duplicate barriers on weakly-ordered archs (diff) | |
| download | linux-dev-fd141fa47c03018aa1f77c335b0f444493e145d5.tar.xz linux-dev-fd141fa47c03018aa1f77c335b0f444493e145d5.zip | |
bnxt_en: Eliminate duplicate barriers on weakly-ordered archs
Code includes wmb() followed by writel(). writel() already has a barrier on
some architectures like arm64.
This ends up CPU observing two barriers back to back before executing the
register write.
Create a new wrapper function with relaxed write operator. Use the new
wrapper when a write is following a wmb().
Since code already has an explicit barrier call, changing writel() to
writel_relaxed().
Also add mmiowb() so that write code doesn't move outside of scope.
Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
Acked-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/ethernet/broadcom/bnxt')
| -rw-r--r-- | drivers/net/ethernet/broadcom/bnxt/bnxt.c | 2 | ||||
| -rw-r--r-- | drivers/net/ethernet/broadcom/bnxt/bnxt.h | 9 |
2 files changed, 10 insertions, 1 deletions
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c index c7e5e6f09647..3ff5f65758a3 100644 --- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c @@ -1922,7 +1922,7 @@ static int bnxt_poll_work(struct bnxt *bp, struct bnxt_napi *bnapi, int budget) /* Sync BD data before updating doorbell */ wmb(); - bnxt_db_write(bp, db, DB_KEY_TX | prod); + bnxt_db_write_relaxed(bp, db, DB_KEY_TX | prod); } cpr->cp_raw_cons = raw_cons; diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.h b/drivers/net/ethernet/broadcom/bnxt/bnxt.h index 5e3d62189cab..960162c9386c 100644 --- a/drivers/net/ethernet/broadcom/bnxt/bnxt.h +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.h @@ -1402,6 +1402,15 @@ static inline u32 bnxt_tx_avail(struct bnxt *bp, struct bnxt_tx_ring_info *txr) ((txr->tx_prod - txr->tx_cons) & bp->tx_ring_mask); } +/* For TX and RX ring doorbells with no ordering guarantee*/ +static inline void bnxt_db_write_relaxed(struct bnxt *bp, void __iomem *db, + u32 val) +{ + writel_relaxed(val, db); + if (bp->flags & BNXT_FLAG_DOUBLE_DB) + writel_relaxed(val, db); +} + /* For TX and RX ring doorbells */ static inline void bnxt_db_write(struct bnxt *bp, void __iomem *db, u32 val) { |