bnxt_en: Optimize doorbell write operations for newer chips.
Older chips require the doorbells to be written twice, but newer chips
do not. Add a new common function bnxt_db_write() to write all
doorbells appropriately depending on the chip. Eliminating the extra
doorbell on newer chips has a significant performance improvement
on pktgen.
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index 427db49..d7c1295 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -463,8 +463,7 @@ static netdev_tx_t bnxt_start_xmit(struct sk_buff *skb, struct net_device *dev)
prod = NEXT_TX(prod);
txr->tx_prod = prod;
- writel(DB_KEY_TX | prod, txr->tx_doorbell);
- writel(DB_KEY_TX | prod, txr->tx_doorbell);
+ bnxt_db_write(bp, txr->tx_doorbell, DB_KEY_TX | prod);
tx_done:
@@ -1779,8 +1778,7 @@ static int bnxt_poll_work(struct bnxt *bp, struct bnxt_napi *bnapi, int budget)
/* Sync BD data before updating doorbell */
wmb();
- writel(DB_KEY_TX | prod, db);
- writel(DB_KEY_TX | prod, db);
+ bnxt_db_write(bp, db, DB_KEY_TX | prod);
}
cpr->cp_raw_cons = raw_cons;
@@ -1796,14 +1794,10 @@ static int bnxt_poll_work(struct bnxt *bp, struct bnxt_napi *bnapi, int budget)
if (event & BNXT_RX_EVENT) {
struct bnxt_rx_ring_info *rxr = bnapi->rx_ring;
- writel(DB_KEY_RX | rxr->rx_prod, rxr->rx_doorbell);
- writel(DB_KEY_RX | rxr->rx_prod, rxr->rx_doorbell);
- if (event & BNXT_AGG_EVENT) {
- writel(DB_KEY_RX | rxr->rx_agg_prod,
- rxr->rx_agg_doorbell);
- writel(DB_KEY_RX | rxr->rx_agg_prod,
- rxr->rx_agg_doorbell);
- }
+ bnxt_db_write(bp, rxr->rx_doorbell, DB_KEY_RX | rxr->rx_prod);
+ if (event & BNXT_AGG_EVENT)
+ bnxt_db_write(bp, rxr->rx_agg_doorbell,
+ DB_KEY_RX | rxr->rx_agg_prod);
}
return rx_pkts;
}
@@ -1863,13 +1857,11 @@ static int bnxt_poll_nitroa0(struct napi_struct *napi, int budget)
cpr->cp_raw_cons = raw_cons;
BNXT_CP_DB(cpr->cp_doorbell, cpr->cp_raw_cons);
- writel(DB_KEY_RX | rxr->rx_prod, rxr->rx_doorbell);
- writel(DB_KEY_RX | rxr->rx_prod, rxr->rx_doorbell);
+ bnxt_db_write(bp, rxr->rx_doorbell, DB_KEY_RX | rxr->rx_prod);
- if (event & BNXT_AGG_EVENT) {
- writel(DB_KEY_RX | rxr->rx_agg_prod, rxr->rx_agg_doorbell);
- writel(DB_KEY_RX | rxr->rx_agg_prod, rxr->rx_agg_doorbell);
- }
+ if (event & BNXT_AGG_EVENT)
+ bnxt_db_write(bp, rxr->rx_agg_doorbell,
+ DB_KEY_RX | rxr->rx_agg_prod);
if (!bnxt_has_work(bp, cpr) && rx_pkts < budget) {
napi_complete_done(napi, rx_pkts);
@@ -7714,6 +7706,8 @@ static int bnxt_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
bp->gro_func = bnxt_gro_func_5730x;
if (BNXT_CHIP_P4_PLUS(bp))
bp->gro_func = bnxt_gro_func_5731x;
+ else
+ bp->flags |= BNXT_FLAG_DOUBLE_DB;
rc = bnxt_hwrm_func_drv_rgtr(bp);
if (rc)