1 files changed, 135 insertions, 110 deletions

diff --git a/drivers/scsi/fcoe/fcoe.c b/drivers/scsi/fcoe/fcoe.c
index 4a43b74..32298ed 100644
--- a/drivers/scsi/fcoe/fcoe.c
+++ b/drivers/scsi/fcoe/fcoe.c
@@ -109,6 +109,7 @@ static struct fc_seq *fcoe_elsct_send(struct fc_lport *,
 						   struct fc_frame *,
 						   void *),
 				      void *, u32 timeout);
+static void fcoe_recv_frame(struct sk_buff *skb);
 
 module_param_call(create, fcoe_create, NULL, NULL, S_IWUSR);
 __MODULE_PARM_TYPE(create, "string");
@@ -1241,11 +1242,25 @@ int fcoe_rcv(struct sk_buff *skb, struct net_device *netdev,
 	 * this skb. We also have this receive thread locked,
 	 * so we're free to queue skbs into it's queue.
 	 */
-	__skb_queue_tail(&fps->fcoe_rx_list, skb);
-	if (fps->fcoe_rx_list.qlen == 1)
-		wake_up_process(fps->thread);
 
-	spin_unlock_bh(&fps->fcoe_rx_list.lock);
+	/* If this is a SCSI-FCP frame, and this is already executing on the
+	 * correct CPU, and the queue for this CPU is empty, then go ahead
+	 * and process the frame directly in the softirq context.
+	 * This lets us process completions without context switching from the
+	 * NET_RX softirq, to our receive processing thread, and then back to
+	 * BLOCK softirq context.
+	 */
+	if (fh->fh_type == FC_TYPE_FCP &&
+	    cpu == smp_processor_id() &&
+	    skb_queue_empty(&fps->fcoe_rx_list)) {
+		spin_unlock_bh(&fps->fcoe_rx_list.lock);
+		fcoe_recv_frame(skb);
+	} else {
+		__skb_queue_tail(&fps->fcoe_rx_list, skb);
+		if (fps->fcoe_rx_list.qlen == 1)
+			wake_up_process(fps->thread);
+		spin_unlock_bh(&fps->fcoe_rx_list.lock);
+	}
 
 	return 0;
 err:
@@ -1503,26 +1518,134 @@ static void fcoe_percpu_flush_done(struct sk_buff *skb)
 }
 
 /**
- * fcoe_percpu_receive_thread() - The per-CPU packet receive thread
- * @arg: The per-CPU context
- *
- * Return: 0 for success
+ * fcoe_recv_frame() - process a single received frame
+ * @skb: frame to process
  */
-int fcoe_percpu_receive_thread(void *arg)
+static void fcoe_recv_frame(struct sk_buff *skb)
 {
-	struct fcoe_percpu_s *p = arg;
 	u32 fr_len;
 	struct fc_lport *lport;
 	struct fcoe_rcv_info *fr;
 	struct fcoe_dev_stats *stats;
 	struct fc_frame_header *fh;
-	struct sk_buff *skb;
 	struct fcoe_crc_eof crc_eof;
 	struct fc_frame *fp;
 	u8 *mac = NULL;
 	struct fcoe_port *port;
 	struct fcoe_hdr *hp;
 
+	fr = fcoe_dev_from_skb(skb);
+	lport = fr->fr_dev;
+	if (unlikely(!lport)) {
+		if (skb->destructor != fcoe_percpu_flush_done)
+			FCOE_NETDEV_DBG(skb->dev, "NULL lport in skb");
+		kfree_skb(skb);
+		return;
+	}
+
+	FCOE_NETDEV_DBG(skb->dev, "skb_info: len:%d data_len:%d "
+			"head:%p data:%p tail:%p end:%p sum:%d dev:%s",
+			skb->len, skb->data_len,
+			skb->head, skb->data, skb_tail_pointer(skb),
+			skb_end_pointer(skb), skb->csum,
+			skb->dev ? skb->dev->name : "<NULL>");
+
+	/*
+	 * Save source MAC address before discarding header.
+	 */
+	port = lport_priv(lport);
+	if (skb_is_nonlinear(skb))
+		skb_linearize(skb);	/* not ideal */
+	mac = eth_hdr(skb)->h_source;
+
+	/*
+	 * Frame length checks and setting up the header pointers
+	 * was done in fcoe_rcv already.
+	 */
+	hp = (struct fcoe_hdr *) skb_network_header(skb);
+	fh = (struct fc_frame_header *) skb_transport_header(skb);
+
+	stats = fc_lport_get_stats(lport);
+	if (unlikely(FC_FCOE_DECAPS_VER(hp) != FC_FCOE_VER)) {
+		if (stats->ErrorFrames < 5)
+			printk(KERN_WARNING "fcoe: FCoE version "
+			       "mismatch: The frame has "
+			       "version %x, but the "
+			       "initiator supports version "
+			       "%x\n", FC_FCOE_DECAPS_VER(hp),
+			       FC_FCOE_VER);
+		stats->ErrorFrames++;
+		kfree_skb(skb);
+		return;
+	}
+
+	skb_pull(skb, sizeof(struct fcoe_hdr));
+	fr_len = skb->len - sizeof(struct fcoe_crc_eof);
+
+	stats->RxFrames++;
+	stats->RxWords += fr_len / FCOE_WORD_TO_BYTE;
+
+	fp = (struct fc_frame *)skb;
+	fc_frame_init(fp);
+	fr_dev(fp) = lport;
+	fr_sof(fp) = hp->fcoe_sof;
+
+	/* Copy out the CRC and EOF trailer for access */
+	if (skb_copy_bits(skb, fr_len, &crc_eof, sizeof(crc_eof))) {
+		kfree_skb(skb);
+		return;
+	}
+	fr_eof(fp) = crc_eof.fcoe_eof;
+	fr_crc(fp) = crc_eof.fcoe_crc32;
+	if (pskb_trim(skb, fr_len)) {
+		kfree_skb(skb);
+		return;
+	}
+
+	/*
+	 * We only check CRC if no offload is available and if it is
+	 * it's solicited data, in which case, the FCP layer would
+	 * check it during the copy.
+	 */
+	if (lport->crc_offload &&
+	    skb->ip_summed == CHECKSUM_UNNECESSARY)
+		fr_flags(fp) &= ~FCPHF_CRC_UNCHECKED;
+	else
+		fr_flags(fp) |= FCPHF_CRC_UNCHECKED;
+
+	fh = fc_frame_header_get(fp);
+	if (fh->fh_r_ctl == FC_RCTL_DD_SOL_DATA &&
+	    fh->fh_type == FC_TYPE_FCP) {
+		fc_exch_recv(lport, fp);
+		return;
+	}
+	if (fr_flags(fp) & FCPHF_CRC_UNCHECKED) {
+		if (le32_to_cpu(fr_crc(fp)) !=
+		    ~crc32(~0, skb->data, fr_len)) {
+			if (stats->InvalidCRCCount < 5)
+				printk(KERN_WARNING "fcoe: dropping "
+				       "frame with CRC error\n");
+			stats->InvalidCRCCount++;
+			stats->ErrorFrames++;
+			fc_frame_free(fp);
+			return;
+		}
+		fr_flags(fp) &= ~FCPHF_CRC_UNCHECKED;
+	}
+	fc_exch_recv(lport, fp);
+}
+
+/**
+ * fcoe_percpu_receive_thread() - The per-CPU packet receive thread
+ * @arg: The per-CPU context
+ *
+ * Return: 0 for success
+ */
+int fcoe_percpu_receive_thread(void *arg)
+{
+	struct fcoe_percpu_s *p = arg;
+	struct sk_buff *skb;
+
 	set_user_nice(current, -20);
 
 	while (!kthread_should_stop()) {
@@ -1538,105 +1661,7 @@ int fcoe_percpu_receive_thread(void *arg)
 			spin_lock_bh(&p->fcoe_rx_list.lock);
 		}
 		spin_unlock_bh(&p->fcoe_rx_list.lock);
-		fr = fcoe_dev_from_skb(skb);
-		lport = fr->fr_dev;
-		if (unlikely(!lport)) {
-			if (skb->destructor != fcoe_percpu_flush_done)
-				FCOE_NETDEV_DBG(skb->dev, "NULL lport in skb");
-			kfree_skb(skb);
-			continue;
-		}
-
-		FCOE_NETDEV_DBG(skb->dev, "skb_info: len:%d data_len:%d "
-				"head:%p data:%p tail:%p end:%p sum:%d dev:%s",
-				skb->len, skb->data_len,
-				skb->head, skb->data, skb_tail_pointer(skb),
-				skb_end_pointer(skb), skb->csum,
-				skb->dev ? skb->dev->name : "<NULL>");
-
-		/*
-		 * Save source MAC address before discarding header.
-		 */
-		port = lport_priv(lport);
-		if (skb_is_nonlinear(skb))
-			skb_linearize(skb);	/* not ideal */
-		mac = eth_hdr(skb)->h_source;
-
-		/*
-		 * Frame length checks and setting up the header pointers
-		 * was done in fcoe_rcv already.
-		 */
-		hp = (struct fcoe_hdr *) skb_network_header(skb);
-		fh = (struct fc_frame_header *) skb_transport_header(skb);
-
-		stats = fc_lport_get_stats(lport);
-		if (unlikely(FC_FCOE_DECAPS_VER(hp) != FC_FCOE_VER)) {
-			if (stats->ErrorFrames < 5)
-				printk(KERN_WARNING "fcoe: FCoE version "
-				       "mismatch: The frame has "
-				       "version %x, but the "
-				       "initiator supports version "
-				       "%x\n", FC_FCOE_DECAPS_VER(hp),
-				       FC_FCOE_VER);
-			stats->ErrorFrames++;
-			kfree_skb(skb);
-			continue;
-		}
-
-		skb_pull(skb, sizeof(struct fcoe_hdr));
-		fr_len = skb->len - sizeof(struct fcoe_crc_eof);
-
-		stats->RxFrames++;
-		stats->RxWords += fr_len / FCOE_WORD_TO_BYTE;
-
-		fp = (struct fc_frame *)skb;
-		fc_frame_init(fp);
-		fr_dev(fp) = lport;
-		fr_sof(fp) = hp->fcoe_sof;
-
-		/* Copy out the CRC and EOF trailer for access */
-		if (skb_copy_bits(skb, fr_len, &crc_eof, sizeof(crc_eof))) {
-			kfree_skb(skb);
-			continue;
-		}
-		fr_eof(fp) = crc_eof.fcoe_eof;
-		fr_crc(fp) = crc_eof.fcoe_crc32;
-		if (pskb_trim(skb, fr_len)) {
-			kfree_skb(skb);
-			continue;
-		}
-
-		/*
-		 * We only check CRC if no offload is available and if it is
-		 * it's solicited data, in which case, the FCP layer would
-		 * check it during the copy.
-		 */
-		if (lport->crc_offload &&
-		    skb->ip_summed == CHECKSUM_UNNECESSARY)
-			fr_flags(fp) &= ~FCPHF_CRC_UNCHECKED;
-		else
-			fr_flags(fp) |= FCPHF_CRC_UNCHECKED;
-
-		fh = fc_frame_header_get(fp);
-		if (fh->fh_r_ctl == FC_RCTL_DD_SOL_DATA &&
-		    fh->fh_type == FC_TYPE_FCP) {
-			fc_exch_recv(lport, fp);
-			continue;
-		}
-		if (fr_flags(fp) & FCPHF_CRC_UNCHECKED) {
-			if (le32_to_cpu(fr_crc(fp)) !=
-			    ~crc32(~0, skb->data, fr_len)) {
-				if (stats->InvalidCRCCount < 5)
-					printk(KERN_WARNING "fcoe: dropping "
-					       "frame with CRC error\n");
-				stats->InvalidCRCCount++;
-				stats->ErrorFrames++;
-				fc_frame_free(fp);
-				continue;
-			}
-			fr_flags(fp) &= ~FCPHF_CRC_UNCHECKED;
-		}
-		fc_exch_recv(lport, fp);
+		fcoe_recv_frame(skb);
 	}
 	return 0;
 }