[PATCH v4 16/17] qed/qede: Eliminate duplicate barriers on weakly-ordered archs
From: Sinan Kaya
Date: Mon Mar 19 2018 - 22:43:34 EST
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().
Signed-off-by: Sinan Kaya <okaya@xxxxxxxxxxxxxx>
---
drivers/net/ethernet/qlogic/qed/qed.h | 5 ++++-
drivers/net/ethernet/qlogic/qed/qed_hw.c | 12 ++++++++++++
drivers/net/ethernet/qlogic/qed/qed_hw.h | 14 ++++++++++++++
drivers/net/ethernet/qlogic/qed/qed_int.c | 2 +-
drivers/net/ethernet/qlogic/qed/qed_l2.c | 2 +-
drivers/net/ethernet/qlogic/qed/qed_ll2.c | 2 +-
drivers/net/ethernet/qlogic/qed/qed_vf.c | 7 ++++---
drivers/net/ethernet/qlogic/qede/qede_ethtool.c | 2 +-
drivers/net/ethernet/qlogic/qede/qede_fp.c | 4 ++--
drivers/net/ethernet/qlogic/qlge/qlge.h | 1 -
include/linux/qed/qed_if.h | 17 +++++++++++++----
11 files changed, 53 insertions(+), 15 deletions(-)
diff --git a/drivers/net/ethernet/qlogic/qed/qed.h b/drivers/net/ethernet/qlogic/qed/qed.h
index 6948855..241077f 100644
--- a/drivers/net/ethernet/qlogic/qed/qed.h
+++ b/drivers/net/ethernet/qlogic/qed/qed.h
@@ -818,12 +818,15 @@ u16 qed_get_cm_pq_idx_vf(struct qed_hwfn *p_hwfn, u16 vf);
(cdev->regview) + \
(offset))
+#define REG_WR_RELAXED(cdev, offset, val) \
+ writel_relaxed((u32)val, REG_ADDR(cdev, offset))
+
#define REG_RD(cdev, offset) readl(REG_ADDR(cdev, offset))
#define REG_WR(cdev, offset, val) writel((u32)val, REG_ADDR(cdev, offset))
#define REG_WR16(cdev, offset, val) writew((u16)val, REG_ADDR(cdev, offset))
#define DOORBELL(cdev, db_addr, val) \
- writel((u32)val, (void __iomem *)((u8 __iomem *)\
+ writel_relaxed((u32)val, (void __iomem *)((u8 __iomem *)\
(cdev->doorbells) + (db_addr)))
/* Prototypes */
diff --git a/drivers/net/ethernet/qlogic/qed/qed_hw.c b/drivers/net/ethernet/qlogic/qed/qed_hw.c
index fca2dbd..1d76121 100644
--- a/drivers/net/ethernet/qlogic/qed/qed_hw.c
+++ b/drivers/net/ethernet/qlogic/qed/qed_hw.c
@@ -222,6 +222,18 @@ struct qed_ptt *qed_get_reserved_ptt(struct qed_hwfn *p_hwfn,
return &p_hwfn->p_ptt_pool->ptts[ptt_idx];
}
+void qed_wr_relaxed(struct qed_hwfn *p_hwfn,
+ struct qed_ptt *p_ptt,
+ u32 hw_addr, u32 val)
+{
+ u32 bar_addr = qed_set_ptt(p_hwfn, p_ptt, hw_addr);
+
+ REG_WR_RELAXED(p_hwfn, bar_addr, val);
+ DP_VERBOSE(p_hwfn, NETIF_MSG_HW,
+ "bar_addr 0x%x, hw_addr 0x%x, val 0x%x\n",
+ bar_addr, hw_addr, val);
+}
+
void qed_wr(struct qed_hwfn *p_hwfn,
struct qed_ptt *p_ptt,
u32 hw_addr, u32 val)
diff --git a/drivers/net/ethernet/qlogic/qed/qed_hw.h b/drivers/net/ethernet/qlogic/qed/qed_hw.h
index 8db2839..bb4f5ff 100644
--- a/drivers/net/ethernet/qlogic/qed/qed_hw.h
+++ b/drivers/net/ethernet/qlogic/qed/qed_hw.h
@@ -152,6 +152,20 @@ struct qed_ptt *qed_get_reserved_ptt(struct qed_hwfn *p_hwfn,
enum reserved_ptts ptt_idx);
/**
+ * @brief qed_wr_relaxed - Write value to BAR using the given ptt
+ * No ordering guarantee.
+ *
+ * @param p_hwfn
+ * @param p_ptt
+ * @param val
+ * @param hw_addr
+ */
+void qed_wr_relaxed(struct qed_hwfn *p_hwfn,
+ struct qed_ptt *p_ptt,
+ u32 hw_addr,
+ u32 val);
+
+/**
* @brief qed_wr - Write value to BAR using the given ptt
*
* @param p_hwfn
diff --git a/drivers/net/ethernet/qlogic/qed/qed_int.c b/drivers/net/ethernet/qlogic/qed/qed_int.c
index d3eabcf..5f09253 100644
--- a/drivers/net/ethernet/qlogic/qed/qed_int.c
+++ b/drivers/net/ethernet/qlogic/qed/qed_int.c
@@ -1747,7 +1747,7 @@ static void qed_int_igu_cleanup_sb(struct qed_hwfn *p_hwfn,
barrier();
- qed_wr(p_hwfn, p_ptt, IGU_REG_COMMAND_REG_CTRL, cmd_ctrl);
+ qed_wr_relaxed(p_hwfn, p_ptt, IGU_REG_COMMAND_REG_CTRL, cmd_ctrl);
/* Flush the write to IGU */
mmiowb();
diff --git a/drivers/net/ethernet/qlogic/qed/qed_l2.c b/drivers/net/ethernet/qlogic/qed/qed_l2.c
index 893ef08..7f3f923b 100644
--- a/drivers/net/ethernet/qlogic/qed/qed_l2.c
+++ b/drivers/net/ethernet/qlogic/qed/qed_l2.c
@@ -921,7 +921,7 @@ qed_eth_pf_rx_queue_start(struct qed_hwfn *p_hwfn,
/* Init the rcq, rx bd and rx sge (if valid) producers to 0 */
__internal_ram_wr(p_hwfn, *pp_prod, sizeof(u32),
- (u32 *)(&init_prod_val));
+ (u32 *)(&init_prod_val), false);
return qed_eth_rxq_start_ramrod(p_hwfn, p_cid,
bd_max_bytes,
diff --git a/drivers/net/ethernet/qlogic/qed/qed_ll2.c b/drivers/net/ethernet/qlogic/qed/qed_ll2.c
index c4f14fd..211f325 100644
--- a/drivers/net/ethernet/qlogic/qed/qed_ll2.c
+++ b/drivers/net/ethernet/qlogic/qed/qed_ll2.c
@@ -1759,7 +1759,7 @@ static void qed_ll2_tx_packet_notify(struct qed_hwfn *p_hwfn,
/* Make sure the BDs data is updated before ringing the doorbell */
wmb();
- DIRECT_REG_WR(p_tx->doorbell_addr, *((u32 *)&db_msg));
+ DIRECT_REG_WR_RELAXED(p_tx->doorbell_addr, *((u32 *)&db_msg));
DP_VERBOSE(p_hwfn,
(NETIF_MSG_TX_QUEUED | QED_MSG_LL2),
diff --git a/drivers/net/ethernet/qlogic/qed/qed_vf.c b/drivers/net/ethernet/qlogic/qed/qed_vf.c
index 91b5e9f..6fa5ccb 100644
--- a/drivers/net/ethernet/qlogic/qed/qed_vf.c
+++ b/drivers/net/ethernet/qlogic/qed/qed_vf.c
@@ -123,7 +123,8 @@ static int qed_send_msg2pf(struct qed_hwfn *p_hwfn, u8 *done, u32 resp_size)
*/
wmb();
- REG_WR(p_hwfn, (uintptr_t)&zone_data->trigger, *((u32 *)&trigger));
+ REG_WR_RELAXED(p_hwfn, (uintptr_t)&zone_data->trigger,
+ *((u32 *)&trigger));
/* When PF would be done with the response, it would write back to the
* `done' address. Poll until then.
@@ -758,7 +759,7 @@ qed_vf_pf_rxq_start(struct qed_hwfn *p_hwfn,
/* Init the rcq, rx bd and rx sge (if valid) producers to 0 */
__internal_ram_wr(p_hwfn, *pp_prod, sizeof(u32),
- (u32 *)(&init_prod_val));
+ (u32 *)(&init_prod_val), false);
}
qed_vf_pf_add_qid(p_hwfn, p_cid);
@@ -788,7 +789,7 @@ qed_vf_pf_rxq_start(struct qed_hwfn *p_hwfn,
/* Init the rcq, rx bd and rx sge (if valid) producers to 0 */
__internal_ram_wr(p_hwfn, *pp_prod, sizeof(u32),
- (u32 *)&init_prod_val);
+ (u32 *)&init_prod_val, false);
}
exit:
qed_vf_pf_req_end(p_hwfn, rc);
diff --git a/drivers/net/ethernet/qlogic/qede/qede_ethtool.c b/drivers/net/ethernet/qlogic/qede/qede_ethtool.c
index 4ca3847..0d9f63a 100644
--- a/drivers/net/ethernet/qlogic/qede/qede_ethtool.c
+++ b/drivers/net/ethernet/qlogic/qede/qede_ethtool.c
@@ -1417,7 +1417,7 @@ static int qede_selftest_transmit_traffic(struct qede_dev *edev,
*/
wmb();
barrier();
- writel(txq->tx_db.raw, txq->doorbell_addr);
+ writel_relaxed(txq->tx_db.raw, txq->doorbell_addr);
/* mmiowb is needed to synchronize doorbell writes from more than one
* processor. It guarantees that the write arrives to the device before
diff --git a/drivers/net/ethernet/qlogic/qede/qede_fp.c b/drivers/net/ethernet/qlogic/qede/qede_fp.c
index dafc079..9dd2124 100644
--- a/drivers/net/ethernet/qlogic/qede/qede_fp.c
+++ b/drivers/net/ethernet/qlogic/qede/qede_fp.c
@@ -318,7 +318,7 @@ static inline void qede_update_tx_producer(struct qede_tx_queue *txq)
*/
wmb();
barrier();
- writel(txq->tx_db.raw, txq->doorbell_addr);
+ writel_relaxed(txq->tx_db.raw, txq->doorbell_addr);
/* mmiowb is needed to synchronize doorbell writes from more than one
* processor. It guarantees that the write arrives to the device before
@@ -581,7 +581,7 @@ void qede_update_rx_prod(struct qede_dev *edev, struct qede_rx_queue *rxq)
wmb();
internal_ram_wr(rxq->hw_rxq_prod_addr, sizeof(rx_prods),
- (u32 *)&rx_prods);
+ (u32 *)&rx_prods, true);
/* mmiowb is needed to synchronize doorbell writes from more than one
* processor. It guarantees that the write arrives to the device before
diff --git a/drivers/net/ethernet/qlogic/qlge/qlge.h b/drivers/net/ethernet/qlogic/qlge/qlge.h
index 1465986..01dfdb5 100644
--- a/drivers/net/ethernet/qlogic/qlge/qlge.h
+++ b/drivers/net/ethernet/qlogic/qlge/qlge.h
@@ -2201,7 +2201,6 @@ static inline void ql_write_db_reg_relaxed(u32 val, void __iomem *addr)
mmiowb();
}
-
/*
* Shadow Registers:
* Outbound queues have a consumer index that is maintained by the chip.
diff --git a/include/linux/qed/qed_if.h b/include/linux/qed/qed_if.h
index 15e398c..70f67ad 100644
--- a/include/linux/qed/qed_if.h
+++ b/include/linux/qed/qed_if.h
@@ -179,6 +179,9 @@ enum qed_led_mode {
QED_LED_MODE_RESTORE
};
+#define DIRECT_REG_WR_RELAXED(reg_addr, val) \
+ writel_relaxed((u32)val, (void __iomem *)(reg_addr))
+
#define DIRECT_REG_WR(reg_addr, val) writel((u32)val, \
(void __iomem *)(reg_addr))
@@ -985,20 +988,26 @@ static inline void qed_sb_ack(struct qed_sb_info *sb_info,
static inline void __internal_ram_wr(void *p_hwfn,
void __iomem *addr,
int size,
- u32 *data)
+ u32 *data,
+ bool relaxed)
{
unsigned int i;
for (i = 0; i < size / sizeof(*data); i++)
- DIRECT_REG_WR(&((u32 __iomem *)addr)[i], data[i]);
+ if (relaxed)
+ DIRECT_REG_WR_RELAXED(&((u32 __iomem *)addr)[i],
+ data[i]);
+ else
+ DIRECT_REG_WR(&((u32 __iomem *)addr)[i], data[i]);
}
static inline void internal_ram_wr(void __iomem *addr,
int size,
- u32 *data)
+ u32 *data,
+ bool relaxed)
{
- __internal_ram_wr(NULL, addr, size, data);
+ __internal_ram_wr(NULL, addr, size, data, relaxed);
}
enum qed_rss_caps {
--
2.7.4