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* [PATCH v2 net-next 0/2] bnx2x: add support for low latency rx
@ 2013-06-18 22:36 Dmitry Kravkov
  2013-06-18 22:36 ` [PATCH v2 net-next 1/2] bnx2x: add support for ndo_ll_poll Dmitry Kravkov
                   ` (2 more replies)
  0 siblings, 3 replies; 5+ messages in thread
From: Dmitry Kravkov @ 2013-06-18 22:36 UTC (permalink / raw)
  To: davem, netdev, eilong; +Cc: Dmitry Kravkov

Hi Dave

This series adds to bnx2x driver capabilities for low latency rx.
It bases on ixgbe driver code and tested with TCP_RR/UDP_RR.
The results show about 50% boost in both scenarious. With second patch
we have additional 5%.

Please, consider applying it to net-next.

V1->V2
	* change function prototypes from int to bool (from Eric)
	* do not allow poll when GRO/LRO enabled

Thanks,
Dmitry

^ permalink raw reply	[flat|nested] 5+ messages in thread

* [PATCH v2 net-next 1/2] bnx2x: add support for ndo_ll_poll
  2013-06-18 22:36 [PATCH v2 net-next 0/2] bnx2x: add support for low latency rx Dmitry Kravkov
@ 2013-06-18 22:36 ` Dmitry Kravkov
  2013-06-19  8:18   ` Eric Dumazet
  2013-06-18 22:36 ` [PATCH v2 net-next 2/2] bnx2x: replace mechanism to check for next available packet Dmitry Kravkov
  2013-06-20  1:32 ` [PATCH v2 net-next 0/2] bnx2x: add support for low latency rx David Miller
  2 siblings, 1 reply; 5+ messages in thread
From: Dmitry Kravkov @ 2013-06-18 22:36 UTC (permalink / raw)
  To: davem, netdev, eilong; +Cc: Dmitry Kravkov

Adds ndo_ll_poll method and locking for FPs between LL and the napi.

When receiving a packet we use skb_mark_ll to record the napi it came from.
Add each napi to the napi_hash right after netif_napi_add().

Signed-off-by: Dmitry Kravkov <dmitry@broadcom.com>
Signed-off-by: Eilon Greenstein <eilong@broadcom.com>
---
 drivers/net/ethernet/broadcom/bnx2x/bnx2x.h      | 125 +++++++++++++++++++++++
 drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c  |  67 ++++++++++--
 drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.h  |  23 ++++-
 drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c |   4 +
 4 files changed, 208 insertions(+), 11 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x.h b/drivers/net/ethernet/broadcom/bnx2x/bnx2x.h
index f76597e..edda716 100644
--- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x.h
+++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x.h
@@ -485,6 +485,21 @@ struct bnx2x_fastpath {
 	struct bnx2x		*bp; /* parent */
 
 	struct napi_struct	napi;
+
+#ifdef CONFIG_NET_LL_RX_POLL
+	unsigned int state;
+#define BNX2X_FP_STATE_IDLE		      0
+#define BNX2X_FP_STATE_NAPI		(1 << 0)    /* NAPI owns this FP */
+#define BNX2X_FP_STATE_POLL		(1 << 1)    /* poll owns this FP */
+#define BNX2X_FP_STATE_NAPI_YIELD	(1 << 2)    /* NAPI yielded this FP */
+#define BNX2X_FP_STATE_POLL_YIELD	(1 << 3)    /* poll yielded this FP */
+#define BNX2X_FP_YIELD	(BNX2X_FP_STATE_NAPI_YIELD | BNX2X_FP_STATE_POLL_YIELD)
+#define BNX2X_FP_LOCKED	(BNX2X_FP_STATE_NAPI | BNX2X_FP_STATE_POLL)
+#define BNX2X_FP_USER_PEND (BNX2X_FP_STATE_POLL | BNX2X_FP_STATE_POLL_YIELD)
+	/* protect state */
+	spinlock_t lock;
+#endif /* CONFIG_NET_LL_RX_POLL */
+
 	union host_hc_status_block	status_blk;
 	/* chip independent shortcuts into sb structure */
 	__le16			*sb_index_values;
@@ -557,6 +572,116 @@ struct bnx2x_fastpath {
 #define bnx2x_fp_stats(bp, fp)	(&((bp)->fp_stats[(fp)->index]))
 #define bnx2x_fp_qstats(bp, fp)	(&((bp)->fp_stats[(fp)->index].eth_q_stats))
 
+#ifdef CONFIG_NET_LL_RX_POLL
+static inline void bnx2x_fp_init_lock(struct bnx2x_fastpath *fp)
+{
+	spin_lock_init(&fp->lock);
+	fp->state = BNX2X_FP_STATE_IDLE;
+}
+
+/* called from the device poll routine to get ownership of a FP */
+static inline bool bnx2x_fp_lock_napi(struct bnx2x_fastpath *fp)
+{
+	bool rc = true;
+
+	spin_lock(&fp->lock);
+	if (fp->state & BNX2X_FP_LOCKED) {
+		WARN_ON(fp->state & BNX2X_FP_STATE_NAPI);
+		fp->state |= BNX2X_FP_STATE_NAPI_YIELD;
+		rc = false;
+	} else {
+		/* we don't care if someone yielded */
+		fp->state = BNX2X_FP_STATE_NAPI;
+	}
+	spin_unlock(&fp->lock);
+	return rc;
+}
+
+/* returns true is someone tried to get the FP while napi had it */
+static inline bool bnx2x_fp_unlock_napi(struct bnx2x_fastpath *fp)
+{
+	bool rc = false;
+
+	spin_lock(&fp->lock);
+	WARN_ON(fp->state &
+		(BNX2X_FP_STATE_POLL | BNX2X_FP_STATE_NAPI_YIELD));
+
+	if (fp->state & BNX2X_FP_STATE_POLL_YIELD)
+		rc = true;
+	fp->state = BNX2X_FP_STATE_IDLE;
+	spin_unlock(&fp->lock);
+	return rc;
+}
+
+/* called from bnx2x_low_latency_poll() */
+static inline bool bnx2x_fp_lock_poll(struct bnx2x_fastpath *fp)
+{
+	bool rc = true;
+
+	spin_lock_bh(&fp->lock);
+	if ((fp->state & BNX2X_FP_LOCKED)) {
+		fp->state |= BNX2X_FP_STATE_POLL_YIELD;
+		rc = false;
+	} else {
+		/* preserve yield marks */
+		fp->state |= BNX2X_FP_STATE_POLL;
+	}
+	spin_unlock_bh(&fp->lock);
+	return rc;
+}
+
+/* returns true if someone tried to get the FP while it was locked */
+static inline bool bnx2x_fp_unlock_poll(struct bnx2x_fastpath *fp)
+{
+	bool rc = false;
+
+	spin_lock_bh(&fp->lock);
+	WARN_ON(fp->state & BNX2X_FP_STATE_NAPI);
+
+	if (fp->state & BNX2X_FP_STATE_POLL_YIELD)
+		rc = true;
+	fp->state = BNX2X_FP_STATE_IDLE;
+	spin_unlock_bh(&fp->lock);
+	return rc;
+}
+
+/* true if a socket is polling, even if it did not get the lock */
+static inline bool bnx2x_fp_ll_polling(struct bnx2x_fastpath *fp)
+{
+	WARN_ON(!(fp->state & BNX2X_FP_LOCKED));
+	return fp->state & BNX2X_FP_USER_PEND;
+}
+#else
+static inline void bnx2x_fp_init_lock(struct bnx2x_fastpath *fp)
+{
+}
+
+static inline bool bnx2x_fp_lock_napi(struct bnx2x_fastpath *fp)
+{
+	return true;
+}
+
+static inline bool bnx2x_fp_unlock_napi(struct bnx2x_fastpath *fp)
+{
+	return false;
+}
+
+static inline bool bnx2x_fp_lock_poll(struct bnx2x_fastpath *fp)
+{
+	return false;
+}
+
+static inline bool bnx2x_fp_unlock_poll(struct bnx2x_fastpath *fp)
+{
+	return false;
+}
+
+static inline bool bnx2x_fp_ll_polling(struct bnx2x_fastpath *fp)
+{
+	return false;
+}
+#endif /* CONFIG_NET_LL_RX_POLL */
+
 /* Use 2500 as a mini-jumbo MTU for FCoE */
 #define BNX2X_FCOE_MINI_JUMBO_MTU	2500
 
diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c
index 4e42bdd..20eefa6 100644
--- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c
+++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c
@@ -24,6 +24,7 @@
 #include <net/tcp.h>
 #include <net/ipv6.h>
 #include <net/ip6_checksum.h>
+#include <net/ll_poll.h>
 #include <linux/prefetch.h>
 #include "bnx2x_cmn.h"
 #include "bnx2x_init.h"
@@ -999,8 +1000,13 @@ reuse_rx:
 		    PARSING_FLAGS_VLAN)
 			__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q),
 					       le16_to_cpu(cqe_fp->vlan_tag));
-		napi_gro_receive(&fp->napi, skb);
 
+		skb_mark_ll(skb, &fp->napi);
+
+		if (bnx2x_fp_ll_polling(fp))
+			netif_receive_skb(skb);
+		else
+			napi_gro_receive(&fp->napi, skb);
 next_rx:
 		rx_buf->data = NULL;
 
@@ -1755,32 +1761,46 @@ static void bnx2x_napi_enable_cnic(struct bnx2x *bp)
 {
 	int i;
 
-	for_each_rx_queue_cnic(bp, i)
+	for_each_rx_queue_cnic(bp, i) {
+		bnx2x_fp_init_lock(&bp->fp[i]);
 		napi_enable(&bnx2x_fp(bp, i, napi));
+	}
 }
 
 static void bnx2x_napi_enable(struct bnx2x *bp)
 {
 	int i;
 
-	for_each_eth_queue(bp, i)
+	for_each_eth_queue(bp, i) {
+		bnx2x_fp_init_lock(&bp->fp[i]);
 		napi_enable(&bnx2x_fp(bp, i, napi));
+	}
 }
 
 static void bnx2x_napi_disable_cnic(struct bnx2x *bp)
 {
 	int i;
 
-	for_each_rx_queue_cnic(bp, i)
+	local_bh_disable();
+	for_each_rx_queue_cnic(bp, i) {
 		napi_disable(&bnx2x_fp(bp, i, napi));
+		while (!bnx2x_fp_lock_napi(&bp->fp[i]))
+			mdelay(1);
+	}
+	local_bh_enable();
 }
 
 static void bnx2x_napi_disable(struct bnx2x *bp)
 {
 	int i;
 
-	for_each_eth_queue(bp, i)
+	local_bh_disable();
+	for_each_eth_queue(bp, i) {
 		napi_disable(&bnx2x_fp(bp, i, napi));
+		while (!bnx2x_fp_lock_napi(&bp->fp[i]))
+			mdelay(1);
+	}
+	local_bh_enable();
 }
 
 void bnx2x_netif_start(struct bnx2x *bp)
@@ -3039,6 +3059,8 @@ int bnx2x_poll(struct napi_struct *napi, int budget)
 			return 0;
 		}
 #endif
+		if (!bnx2x_fp_lock_napi(fp))
+			return work_done;
 
 		for_each_cos_in_tx_queue(fp, cos)
 			if (bnx2x_tx_queue_has_work(fp->txdata_ptr[cos]))
@@ -3048,12 +3070,15 @@ int bnx2x_poll(struct napi_struct *napi, int budget)
 			work_done += bnx2x_rx_int(fp, budget - work_done);
 
 			/* must not complete if we consumed full budget */
-			if (work_done >= budget)
+			if (work_done >= budget) {
+				bnx2x_fp_unlock_napi(fp);
 				break;
+			}
 		}
 
 		/* Fall out from the NAPI loop if needed */
-		if (!(bnx2x_has_rx_work(fp) || bnx2x_has_tx_work(fp))) {
+		if (!bnx2x_fp_unlock_napi(fp) &&
+		    !(bnx2x_has_rx_work(fp) || bnx2x_has_tx_work(fp))) {
 
 			/* No need to update SB for FCoE L2 ring as long as
 			 * it's connected to the default SB and the SB
@@ -3095,6 +3120,34 @@ int bnx2x_poll(struct napi_struct *napi, int budget)
 	return work_done;
 }
 
+#ifdef CONFIG_NET_LL_RX_POLL
+/* must be called with local_bh_disable()d */
+int bnx2x_low_latency_recv(struct napi_struct *napi)
+{
+	struct bnx2x_fastpath *fp = container_of(napi, struct bnx2x_fastpath,
+						 napi);
+	struct bnx2x *bp = fp->bp;
+	int found = 0;
+
+	if ((bp->state == BNX2X_STATE_CLOSED) ||
+	    (bp->state == BNX2X_STATE_ERROR) ||
+	    (bp->flags & (TPA_ENABLE_FLAG | GRO_ENABLE_FLAG)))
+		return LL_FLUSH_FAILED;
+
+	if (!bnx2x_fp_lock_poll(fp))
+		return LL_FLUSH_BUSY;
+
+	if (bnx2x_has_rx_work(fp)) {
+		bnx2x_update_fpsb_idx(fp);
+		found = bnx2x_rx_int(fp, 4);
+	}
+
+	bnx2x_fp_unlock_poll(fp);
+
+	return found;
+}
+#endif
+
 /* we split the first BD into headers and data BDs
  * to ease the pain of our fellow microcode engineers
  * we use one mapping for both BDs
diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.h b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.h
index 650bb52..a1a5cdc 100644
--- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.h
+++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.h
@@ -605,6 +605,13 @@ int bnx2x_enable_msi(struct bnx2x *bp);
 int bnx2x_poll(struct napi_struct *napi, int budget);
 
 /**
+ * bnx2x_low_latency_recv - LL callback
+ *
+ * @napi:	napi structure
+ */
+int bnx2x_low_latency_recv(struct napi_struct *napi);
+
+/**
  * bnx2x_alloc_mem_bp - allocate memories outsize main driver structure
  *
  * @bp:		driver handle
@@ -846,9 +853,11 @@ static inline void bnx2x_add_all_napi_cnic(struct bnx2x *bp)
 	int i;
 
 	/* Add NAPI objects */
-	for_each_rx_queue_cnic(bp, i)
+	for_each_rx_queue_cnic(bp, i) {
 		netif_napi_add(bp->dev, &bnx2x_fp(bp, i, napi),
 			       bnx2x_poll, NAPI_POLL_WEIGHT);
+		napi_hash_add(&bnx2x_fp(bp, i, napi));
+	}
 }
 
 static inline void bnx2x_add_all_napi(struct bnx2x *bp)
@@ -856,25 +865,31 @@ static inline void bnx2x_add_all_napi(struct bnx2x *bp)
 	int i;
 
 	/* Add NAPI objects */
-	for_each_eth_queue(bp, i)
+	for_each_eth_queue(bp, i) {
 		netif_napi_add(bp->dev, &bnx2x_fp(bp, i, napi),
 			       bnx2x_poll, NAPI_POLL_WEIGHT);
+		napi_hash_add(&bnx2x_fp(bp, i, napi));
+	}
 }
 
 static inline void bnx2x_del_all_napi_cnic(struct bnx2x *bp)
 {
 	int i;
 
-	for_each_rx_queue_cnic(bp, i)
+	for_each_rx_queue_cnic(bp, i) {
+		napi_hash_del(&bnx2x_fp(bp, i, napi));
 		netif_napi_del(&bnx2x_fp(bp, i, napi));
+	}
 }
 
 static inline void bnx2x_del_all_napi(struct bnx2x *bp)
 {
 	int i;
 
-	for_each_eth_queue(bp, i)
+	for_each_eth_queue(bp, i) {
+		napi_hash_del(&bnx2x_fp(bp, i, napi));
 		netif_napi_del(&bnx2x_fp(bp, i, napi));
+	}
 }
 
 int bnx2x_set_int_mode(struct bnx2x *bp);
diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c
index 658b9fd..e2e8705 100644
--- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c
+++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c
@@ -12013,6 +12013,10 @@ static const struct net_device_ops bnx2x_netdev_ops = {
 #ifdef NETDEV_FCOE_WWNN
 	.ndo_fcoe_get_wwn	= bnx2x_fcoe_get_wwn,
 #endif
+
+#ifdef CONFIG_NET_LL_RX_POLL
+	.ndo_ll_poll		= bnx2x_low_latency_recv,
+#endif
 };
 
 static int bnx2x_set_coherency_mask(struct bnx2x *bp)
-- 
1.8.1.4

^ permalink raw reply related	[flat|nested] 5+ messages in thread

* [PATCH v2 net-next 2/2] bnx2x: replace mechanism to check for next available packet
  2013-06-18 22:36 [PATCH v2 net-next 0/2] bnx2x: add support for low latency rx Dmitry Kravkov
  2013-06-18 22:36 ` [PATCH v2 net-next 1/2] bnx2x: add support for ndo_ll_poll Dmitry Kravkov
@ 2013-06-18 22:36 ` Dmitry Kravkov
  2013-06-20  1:32 ` [PATCH v2 net-next 0/2] bnx2x: add support for low latency rx David Miller
  2 siblings, 0 replies; 5+ messages in thread
From: Dmitry Kravkov @ 2013-06-18 22:36 UTC (permalink / raw)
  To: davem, netdev, eilong; +Cc: Dmitry Kravkov

Check next packet availability by validating that HW has finished CQE
placement. This saves latency of another dma transaction performed to update
SB indexes.

Signed-off-by: Dmitry Kravkov <dmitry@broadcom.com>
Signed-off-by: Eilon Greenstein <eilong@broadcom.com>
---
 drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c  | 49 ++++++++++--------------
 drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.h  | 26 +++++++++----
 drivers/net/ethernet/broadcom/bnx2x/bnx2x_hsi.h  |  3 +-
 drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c |  1 -
 4 files changed, 42 insertions(+), 37 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c
index 20eefa6..ca7f2bb 100644
--- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c
+++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c
@@ -804,40 +804,32 @@ int bnx2x_rx_int(struct bnx2x_fastpath *fp, int budget)
 {
 	struct bnx2x *bp = fp->bp;
 	u16 bd_cons, bd_prod, bd_prod_fw, comp_ring_cons;
-	u16 hw_comp_cons, sw_comp_cons, sw_comp_prod;
+	u16 sw_comp_cons, sw_comp_prod;
 	int rx_pkt = 0;
+	union eth_rx_cqe *cqe;
+	struct eth_fast_path_rx_cqe *cqe_fp;
 
 #ifdef BNX2X_STOP_ON_ERROR
 	if (unlikely(bp->panic))
 		return 0;
 #endif
 
-	/* CQ "next element" is of the size of the regular element,
-	   that's why it's ok here */
-	hw_comp_cons = le16_to_cpu(*fp->rx_cons_sb);
-	if ((hw_comp_cons & MAX_RCQ_DESC_CNT) == MAX_RCQ_DESC_CNT)
-		hw_comp_cons++;
-
 	bd_cons = fp->rx_bd_cons;
 	bd_prod = fp->rx_bd_prod;
 	bd_prod_fw = bd_prod;
 	sw_comp_cons = fp->rx_comp_cons;
 	sw_comp_prod = fp->rx_comp_prod;
 
-	/* Memory barrier necessary as speculative reads of the rx
-	 * buffer can be ahead of the index in the status block
-	 */
-	rmb();
+	comp_ring_cons = RCQ_BD(sw_comp_cons);
+	cqe = &fp->rx_comp_ring[comp_ring_cons];
+	cqe_fp = &cqe->fast_path_cqe;
 
 	DP(NETIF_MSG_RX_STATUS,
-	   "queue[%d]:  hw_comp_cons %u  sw_comp_cons %u\n",
-	   fp->index, hw_comp_cons, sw_comp_cons);
+	   "queue[%d]: sw_comp_cons %u\n", fp->index, sw_comp_cons);
 
-	while (sw_comp_cons != hw_comp_cons) {
+	while (BNX2X_IS_CQE_COMPLETED(cqe_fp)) {
 		struct sw_rx_bd *rx_buf = NULL;
 		struct sk_buff *skb;
-		union eth_rx_cqe *cqe;
-		struct eth_fast_path_rx_cqe *cqe_fp;
 		u8 cqe_fp_flags;
 		enum eth_rx_cqe_type cqe_fp_type;
 		u16 len, pad, queue;
@@ -849,12 +841,9 @@ int bnx2x_rx_int(struct bnx2x_fastpath *fp, int budget)
 			return 0;
 #endif
 
-		comp_ring_cons = RCQ_BD(sw_comp_cons);
 		bd_prod = RX_BD(bd_prod);
 		bd_cons = RX_BD(bd_cons);
 
-		cqe = &fp->rx_comp_ring[comp_ring_cons];
-		cqe_fp = &cqe->fast_path_cqe;
 		cqe_fp_flags = cqe_fp->type_error_flags;
 		cqe_fp_type = cqe_fp_flags & ETH_FAST_PATH_RX_CQE_TYPE;
 
@@ -1018,8 +1007,15 @@ next_cqe:
 		sw_comp_prod = NEXT_RCQ_IDX(sw_comp_prod);
 		sw_comp_cons = NEXT_RCQ_IDX(sw_comp_cons);
 
+		/* mark CQE as free */
+		BNX2X_SEED_CQE(cqe_fp);
+
 		if (rx_pkt == budget)
 			break;
+
+		comp_ring_cons = RCQ_BD(sw_comp_cons);
+		cqe = &fp->rx_comp_ring[comp_ring_cons];
+		cqe_fp = &cqe->fast_path_cqe;
 	} /* while */
 
 	fp->rx_bd_cons = bd_cons;
@@ -1055,8 +1051,6 @@ static irqreturn_t bnx2x_msix_fp_int(int irq, void *fp_cookie)
 #endif
 
 	/* Handle Rx and Tx according to MSI-X vector */
-	prefetch(fp->rx_cons_sb);
-
 	for_each_cos_in_tx_queue(fp, cos)
 		prefetch(fp->txdata_ptr[cos]->tx_cons_sb);
 
@@ -3137,10 +3131,8 @@ int bnx2x_low_latency_recv(struct napi_struct *napi)
 	if (!bnx2x_fp_lock_poll(fp))
 		return LL_FLUSH_BUSY;
 
-	if (bnx2x_has_rx_work(fp)) {
-		bnx2x_update_fpsb_idx(fp);
+	if (bnx2x_has_rx_work(fp))
 		found = bnx2x_rx_int(fp, 4);
-	}
 
 	bnx2x_fp_unlock_poll(fp);
 
@@ -4339,10 +4331,11 @@ static int bnx2x_alloc_fp_mem_at(struct bnx2x *bp, int index)
 				&bnx2x_fp(bp, index, rx_desc_mapping),
 				sizeof(struct eth_rx_bd) * NUM_RX_BD);
 
-		BNX2X_PCI_ALLOC(bnx2x_fp(bp, index, rx_comp_ring),
-				&bnx2x_fp(bp, index, rx_comp_mapping),
-				sizeof(struct eth_fast_path_rx_cqe) *
-				NUM_RCQ_BD);
+		/* Seed all CQEs by 1s */
+		BNX2X_PCI_FALLOC(bnx2x_fp(bp, index, rx_comp_ring),
+				 &bnx2x_fp(bp, index, rx_comp_mapping),
+				 sizeof(struct eth_fast_path_rx_cqe) *
+				 NUM_RCQ_BD);
 
 		/* SGE ring */
 		BNX2X_ALLOC(bnx2x_fp(bp, index, rx_page_ring),
diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.h b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.h
index a1a5cdc..c07a6d0 100644
--- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.h
+++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.h
@@ -59,6 +59,16 @@ extern int int_mode;
 		   (unsigned long long)(*y), x); \
 	} while (0)
 
+#define BNX2X_PCI_FALLOC(x, y, size) \
+	do { \
+		x = dma_alloc_coherent(&bp->pdev->dev, size, y, GFP_KERNEL); \
+		if (x == NULL) \
+			goto alloc_mem_err; \
+		memset((void *)x, 0xFFFFFFFF, size); \
+		DP(NETIF_MSG_HW, "BNX2X_PCI_FALLOC: Physical %Lx Virtual %p\n",\
+		   (unsigned long long)(*y), x); \
+	} while (0)
+
 #define BNX2X_ALLOC(x, size) \
 	do { \
 		x = kzalloc(size, GFP_KERNEL); \
@@ -805,16 +815,18 @@ static inline bool bnx2x_has_tx_work(struct bnx2x_fastpath *fp)
 	return false;
 }
 
+#define BNX2X_IS_CQE_COMPLETED(cqe_fp) (cqe_fp->marker == 0x0)
+#define BNX2X_SEED_CQE(cqe_fp) (cqe_fp->marker = 0xFFFFFFFF)
 static inline int bnx2x_has_rx_work(struct bnx2x_fastpath *fp)
 {
-	u16 rx_cons_sb;
+	u16 cons;
+	union eth_rx_cqe *cqe;
+	struct eth_fast_path_rx_cqe *cqe_fp;
 
-	/* Tell compiler that status block fields can change */
-	barrier();
-	rx_cons_sb = le16_to_cpu(*fp->rx_cons_sb);
-	if ((rx_cons_sb & MAX_RCQ_DESC_CNT) == MAX_RCQ_DESC_CNT)
-		rx_cons_sb++;
-	return (fp->rx_comp_cons != rx_cons_sb);
+	cons = RCQ_BD(fp->rx_comp_cons);
+	cqe = &fp->rx_comp_ring[cons];
+	cqe_fp = &cqe->fast_path_cqe;
+	return BNX2X_IS_CQE_COMPLETED(cqe_fp);
 }
 
 /**
diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_hsi.h b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_hsi.h
index 5ef3f96..5018e52 100644
--- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_hsi.h
+++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_hsi.h
@@ -3818,7 +3818,8 @@ struct eth_fast_path_rx_cqe {
 	__le16 len_on_bd;
 	struct parsing_flags pars_flags;
 	union eth_sgl_or_raw_data sgl_or_raw_data;
-	__le32 reserved1[8];
+	__le32 reserved1[7];
+	u32 marker;
 };
 
 
diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c
index e2e8705..f0d21fa 100644
--- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c
+++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c
@@ -1866,7 +1866,6 @@ irqreturn_t bnx2x_interrupt(int irq, void *dev_instance)
 		mask = 0x2 << (fp->index + CNIC_SUPPORT(bp));
 		if (status & mask) {
 			/* Handle Rx or Tx according to SB id */
-			prefetch(fp->rx_cons_sb);
 			for_each_cos_in_tx_queue(fp, cos)
 				prefetch(fp->txdata_ptr[cos]->tx_cons_sb);
 			prefetch(&fp->sb_running_index[SM_RX_ID]);
-- 
1.8.1.4

^ permalink raw reply related	[flat|nested] 5+ messages in thread

* Re: [PATCH v2 net-next 1/2] bnx2x: add support for ndo_ll_poll
  2013-06-18 22:36 ` [PATCH v2 net-next 1/2] bnx2x: add support for ndo_ll_poll Dmitry Kravkov
@ 2013-06-19  8:18   ` Eric Dumazet
  0 siblings, 0 replies; 5+ messages in thread
From: Eric Dumazet @ 2013-06-19  8:18 UTC (permalink / raw)
  To: Dmitry Kravkov; +Cc: davem, netdev, eilong

On Wed, 2013-06-19 at 01:36 +0300, Dmitry Kravkov wrote:
> Adds ndo_ll_poll method and locking for FPs between LL and the napi.
> 
> When receiving a packet we use skb_mark_ll to record the napi it came from.
> Add each napi to the napi_hash right after netif_napi_add().
> 
> Signed-off-by: Dmitry Kravkov <dmitry@broadcom.com>
> Signed-off-by: Eilon Greenstein <eilong@broadcom.com>
> ---

Reviewed-by: Eric Dumazet <edumazet@google.com>

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH v2 net-next 0/2] bnx2x: add support for low latency rx
  2013-06-18 22:36 [PATCH v2 net-next 0/2] bnx2x: add support for low latency rx Dmitry Kravkov
  2013-06-18 22:36 ` [PATCH v2 net-next 1/2] bnx2x: add support for ndo_ll_poll Dmitry Kravkov
  2013-06-18 22:36 ` [PATCH v2 net-next 2/2] bnx2x: replace mechanism to check for next available packet Dmitry Kravkov
@ 2013-06-20  1:32 ` David Miller
  2 siblings, 0 replies; 5+ messages in thread
From: David Miller @ 2013-06-20  1:32 UTC (permalink / raw)
  To: dmitry; +Cc: netdev, eilong

From: "Dmitry Kravkov" <dmitry@broadcom.com>
Date: Wed, 19 Jun 2013 01:36:03 +0300

> This series adds to bnx2x driver capabilities for low latency rx.
> It bases on ixgbe driver code and tested with TCP_RR/UDP_RR.
> The results show about 50% boost in both scenarious. With second patch
> we have additional 5%.
> 
> Please, consider applying it to net-next.

Applied, thanks.

^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2013-06-20  1:32 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2013-06-18 22:36 [PATCH v2 net-next 0/2] bnx2x: add support for low latency rx Dmitry Kravkov
2013-06-18 22:36 ` [PATCH v2 net-next 1/2] bnx2x: add support for ndo_ll_poll Dmitry Kravkov
2013-06-19  8:18   ` Eric Dumazet
2013-06-18 22:36 ` [PATCH v2 net-next 2/2] bnx2x: replace mechanism to check for next available packet Dmitry Kravkov
2013-06-20  1:32 ` [PATCH v2 net-next 0/2] bnx2x: add support for low latency rx David Miller

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