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From: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
To: davem@davemloft.net
Cc: Alexander Duyck <alexander.h.duyck@intel.com>,
	netdev@vger.kernel.org, gospo@redhat.com,
	Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Subject: [net-next 05/13] igb: streamline Rx buffer allocation and cleanup
Date: Sat, 17 Sep 2011 01:04:29 -0700	[thread overview]
Message-ID: <1316246677-8830-6-git-send-email-jeffrey.t.kirsher@intel.com> (raw)
In-Reply-To: <1316246677-8830-1-git-send-email-jeffrey.t.kirsher@intel.com>

From: Alexander Duyck <alexander.h.duyck@intel.com>

This change is meant to streamline the Rx buffer allocation and cleanup.
This is accomplished by reducing the number of writes by only having the Rx
descriptor ring written by software during allocation, and it will only be
read during cleanup.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by:  Aaron Brown  <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
---
 drivers/net/ethernet/intel/igb/igb.h      |    2 +-
 drivers/net/ethernet/intel/igb/igb_main.c |  190 ++++++++++++++++-------------
 2 files changed, 104 insertions(+), 88 deletions(-)

diff --git a/drivers/net/ethernet/intel/igb/igb.h b/drivers/net/ethernet/intel/igb/igb.h
index 50632b1..b2f2a8c 100644
--- a/drivers/net/ethernet/intel/igb/igb.h
+++ b/drivers/net/ethernet/intel/igb/igb.h
@@ -370,7 +370,7 @@ extern void igb_setup_rctl(struct igb_adapter *);
 extern netdev_tx_t igb_xmit_frame_ring_adv(struct sk_buff *, struct igb_ring *);
 extern void igb_unmap_and_free_tx_resource(struct igb_ring *,
 					   struct igb_buffer *);
-extern void igb_alloc_rx_buffers_adv(struct igb_ring *, int);
+extern void igb_alloc_rx_buffers_adv(struct igb_ring *, u16);
 extern void igb_update_stats(struct igb_adapter *, struct rtnl_link_stats64 *);
 extern bool igb_has_link(struct igb_adapter *adapter);
 extern void igb_set_ethtool_ops(struct net_device *);
diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c
index 022c442..af8c2f7 100644
--- a/drivers/net/ethernet/intel/igb/igb_main.c
+++ b/drivers/net/ethernet/intel/igb/igb_main.c
@@ -3243,16 +3243,15 @@ static void igb_free_all_rx_resources(struct igb_adapter *adapter)
  **/
 static void igb_clean_rx_ring(struct igb_ring *rx_ring)
 {
-	struct igb_buffer *buffer_info;
 	unsigned long size;
-	unsigned int i;
+	u16 i;
 
 	if (!rx_ring->buffer_info)
 		return;
 
 	/* Free all the Rx ring sk_buffs */
 	for (i = 0; i < rx_ring->count; i++) {
-		buffer_info = &rx_ring->buffer_info[i];
+		struct igb_buffer *buffer_info = &rx_ring->buffer_info[i];
 		if (buffer_info->dma) {
 			dma_unmap_single(rx_ring->dev,
 			                 buffer_info->dma,
@@ -5764,7 +5763,7 @@ static bool igb_clean_rx_irq_adv(struct igb_q_vector *q_vector,
 	struct igb_buffer *buffer_info , *next_buffer;
 	struct sk_buff *skb;
 	bool cleaned = false;
-	int cleaned_count = 0;
+	u16 cleaned_count = igb_desc_unused(rx_ring);
 	int current_node = numa_node_id();
 	unsigned int total_bytes = 0, total_packets = 0;
 	unsigned int i;
@@ -5848,7 +5847,6 @@ static bool igb_clean_rx_irq_adv(struct igb_q_vector *q_vector,
 		igb_rx_checksum_adv(rx_ring, staterr, skb);
 
 		skb->protocol = eth_type_trans(skb, netdev);
-		skb_record_rx_queue(skb, rx_ring->queue_index);
 
 		if (staterr & E1000_RXD_STAT_VP) {
 			u16 vid = le16_to_cpu(rx_desc->wb.upper.vlan);
@@ -5858,8 +5856,6 @@ static bool igb_clean_rx_irq_adv(struct igb_q_vector *q_vector,
 		napi_gro_receive(&q_vector->napi, skb);
 
 next_desc:
-		rx_desc->wb.upper.status_error = 0;
-
 		/* return some buffers to hardware, one at a time is too slow */
 		if (cleaned_count >= IGB_RX_BUFFER_WRITE) {
 			igb_alloc_rx_buffers_adv(rx_ring, cleaned_count);
@@ -5873,110 +5869,130 @@ next_desc:
 	}
 
 	rx_ring->next_to_clean = i;
-	cleaned_count = igb_desc_unused(rx_ring);
-
-	if (cleaned_count)
-		igb_alloc_rx_buffers_adv(rx_ring, cleaned_count);
-
-	rx_ring->total_packets += total_packets;
-	rx_ring->total_bytes += total_bytes;
 	u64_stats_update_begin(&rx_ring->rx_syncp);
 	rx_ring->rx_stats.packets += total_packets;
 	rx_ring->rx_stats.bytes += total_bytes;
 	u64_stats_update_end(&rx_ring->rx_syncp);
+	rx_ring->total_packets += total_packets;
+	rx_ring->total_bytes += total_bytes;
+
+	if (cleaned_count)
+		igb_alloc_rx_buffers_adv(rx_ring, cleaned_count);
+
 	return cleaned;
 }
 
+static bool igb_alloc_mapped_skb(struct igb_ring *rx_ring,
+				 struct igb_buffer *bi)
+{
+	struct sk_buff *skb = bi->skb;
+	dma_addr_t dma = bi->dma;
+
+	if (dma)
+		return true;
+
+	if (likely(!skb)) {
+		skb = netdev_alloc_skb_ip_align(rx_ring->netdev,
+						IGB_RX_HDR_LEN);
+		bi->skb = skb;
+		if (!skb) {
+			rx_ring->rx_stats.alloc_failed++;
+			return false;
+		}
+
+		/* initialize skb for ring */
+		skb_record_rx_queue(skb, rx_ring->queue_index);
+	}
+
+	dma = dma_map_single(rx_ring->dev, skb->data,
+			     IGB_RX_HDR_LEN, DMA_FROM_DEVICE);
+
+	if (dma_mapping_error(rx_ring->dev, dma)) {
+		rx_ring->rx_stats.alloc_failed++;
+		return false;
+	}
+
+	bi->dma = dma;
+	return true;
+}
+
+static bool igb_alloc_mapped_page(struct igb_ring *rx_ring,
+				  struct igb_buffer *bi)
+{
+	struct page *page = bi->page;
+	dma_addr_t page_dma = bi->page_dma;
+	unsigned int page_offset = bi->page_offset ^ (PAGE_SIZE / 2);
+
+	if (page_dma)
+		return true;
+
+	if (!page) {
+		page = netdev_alloc_page(rx_ring->netdev);
+		bi->page = page;
+		if (unlikely(!page)) {
+			rx_ring->rx_stats.alloc_failed++;
+			return false;
+		}
+	}
+
+	page_dma = dma_map_page(rx_ring->dev, page,
+				page_offset, PAGE_SIZE / 2,
+				DMA_FROM_DEVICE);
+
+	if (dma_mapping_error(rx_ring->dev, page_dma)) {
+		rx_ring->rx_stats.alloc_failed++;
+		return false;
+	}
+
+	bi->page_dma = page_dma;
+	bi->page_offset = page_offset;
+	return true;
+}
+
 /**
  * igb_alloc_rx_buffers_adv - Replace used receive buffers; packet split
  * @adapter: address of board private structure
  **/
-void igb_alloc_rx_buffers_adv(struct igb_ring *rx_ring, int cleaned_count)
+void igb_alloc_rx_buffers_adv(struct igb_ring *rx_ring, u16 cleaned_count)
 {
-	struct net_device *netdev = rx_ring->netdev;
 	union e1000_adv_rx_desc *rx_desc;
-	struct igb_buffer *buffer_info;
-	struct sk_buff *skb;
-	unsigned int i;
+	struct igb_buffer *bi;
+	u16 i = rx_ring->next_to_use;
 
-	i = rx_ring->next_to_use;
-	buffer_info = &rx_ring->buffer_info[i];
+	rx_desc = E1000_RX_DESC_ADV(*rx_ring, i);
+	bi = &rx_ring->buffer_info[i];
+	i -= rx_ring->count;
 
 	while (cleaned_count--) {
-		rx_desc = E1000_RX_DESC_ADV(*rx_ring, i);
-
-		if (!buffer_info->page_dma) {
-			if (!buffer_info->page) {
-				buffer_info->page = netdev_alloc_page(netdev);
-				if (unlikely(!buffer_info->page)) {
-					u64_stats_update_begin(&rx_ring->rx_syncp);
-					rx_ring->rx_stats.alloc_failed++;
-					u64_stats_update_end(&rx_ring->rx_syncp);
-					goto no_buffers;
-				}
-				buffer_info->page_offset = 0;
-			} else {
-				buffer_info->page_offset ^= PAGE_SIZE / 2;
-			}
-			buffer_info->page_dma =
-				dma_map_page(rx_ring->dev, buffer_info->page,
-					     buffer_info->page_offset,
-					     PAGE_SIZE / 2,
-					     DMA_FROM_DEVICE);
-			if (dma_mapping_error(rx_ring->dev,
-					      buffer_info->page_dma)) {
-				buffer_info->page_dma = 0;
-				u64_stats_update_begin(&rx_ring->rx_syncp);
-				rx_ring->rx_stats.alloc_failed++;
-				u64_stats_update_end(&rx_ring->rx_syncp);
-				goto no_buffers;
-			}
-		}
+		if (!igb_alloc_mapped_skb(rx_ring, bi))
+			break;
 
-		skb = buffer_info->skb;
-		if (!skb) {
-			skb = netdev_alloc_skb_ip_align(netdev, IGB_RX_HDR_LEN);
-			if (unlikely(!skb)) {
-				u64_stats_update_begin(&rx_ring->rx_syncp);
-				rx_ring->rx_stats.alloc_failed++;
-				u64_stats_update_end(&rx_ring->rx_syncp);
-				goto no_buffers;
-			}
+		/* Refresh the desc even if buffer_addrs didn't change
+		 * because each write-back erases this info. */
+		rx_desc->read.hdr_addr = cpu_to_le64(bi->dma);
 
-			buffer_info->skb = skb;
-		}
-		if (!buffer_info->dma) {
-			buffer_info->dma = dma_map_single(rx_ring->dev,
-			                                  skb->data,
-							  IGB_RX_HDR_LEN,
-							  DMA_FROM_DEVICE);
-			if (dma_mapping_error(rx_ring->dev,
-					      buffer_info->dma)) {
-				buffer_info->dma = 0;
-				u64_stats_update_begin(&rx_ring->rx_syncp);
-				rx_ring->rx_stats.alloc_failed++;
-				u64_stats_update_end(&rx_ring->rx_syncp);
-				goto no_buffers;
-			}
-		}
-		/* Refresh the desc even if buffer_addrs didn't change because
-		 * each write-back erases this info. */
-		rx_desc->read.pkt_addr = cpu_to_le64(buffer_info->page_dma);
-		rx_desc->read.hdr_addr = cpu_to_le64(buffer_info->dma);
+		if (!igb_alloc_mapped_page(rx_ring, bi))
+			break;
+
+		rx_desc->read.pkt_addr = cpu_to_le64(bi->page_dma);
 
+		rx_desc++;
+		bi++;
 		i++;
-		if (i == rx_ring->count)
-			i = 0;
-		buffer_info = &rx_ring->buffer_info[i];
+		if (unlikely(!i)) {
+			rx_desc = E1000_RX_DESC_ADV(*rx_ring, 0);
+			bi = rx_ring->buffer_info;
+			i -= rx_ring->count;
+		}
+
+		/* clear the hdr_addr for the next_to_use descriptor */
+		rx_desc->read.hdr_addr = 0;
 	}
 
-no_buffers:
+	i += rx_ring->count;
+
 	if (rx_ring->next_to_use != i) {
 		rx_ring->next_to_use = i;
-		if (i == 0)
-			i = (rx_ring->count - 1);
-		else
-			i--;
 
 		/* Force memory writes to complete before letting h/w
 		 * know there are new descriptors to fetch.  (Only
-- 
1.7.6

  parent reply	other threads:[~2011-09-17  8:04 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-09-17  8:04 [net-next 00/13][pull request] Intel Wired LAN Driver Updates Jeff Kirsher
2011-09-17  8:04 ` [net-next 01/13] ixgb: eliminate checkstack warnings Jeff Kirsher
2011-09-17  8:43   ` Joe Perches
2011-09-19 21:36     ` Jesse Brandeburg
2011-09-19 22:28       ` [PATCH] intel: Convert <FOO>_LENGTH_OF_ADDRESS to ETH_ALEN Joe Perches
2011-09-19 23:33         ` Jeff Kirsher
2011-09-17  8:04 ` [net-next 02/13] igb: Update RXDCTL/TXDCTL configurations Jeff Kirsher
2011-09-17  8:04 ` [net-next 03/13] igb: Update max_frame_size to account for an optional VLAN tag if present Jeff Kirsher
2011-09-17  8:04 ` [net-next 04/13] igb: drop support for single buffer mode Jeff Kirsher
2011-09-17  8:04 ` Jeff Kirsher [this message]
2011-09-17  8:04 ` [net-next 06/13] igb: update ring and adapter structure to improve performance Jeff Kirsher
2011-09-17  8:04 ` [net-next 07/13] igb: Refactor clean_rx_irq to reduce overhead and " Jeff Kirsher
2011-09-17  8:04 ` [net-next 08/13] igb: drop the "adv" off function names relating to descriptors Jeff Kirsher
2011-09-17  8:04 ` [net-next 09/13] igb: Replace E1000_XX_DESC_ADV with IGB_XX_DESC Jeff Kirsher
2011-09-17  8:04 ` [net-next 10/13] igb: Remove multi_tx_table and simplify igb_xmit_frame Jeff Kirsher
2011-09-17  8:04 ` [net-next 11/13] igb: Make Tx budget for NAPI user adjustable Jeff Kirsher
2011-09-17 17:04   ` Ben Hutchings
2011-09-19 15:48     ` Alexander Duyck
2011-09-19 16:05       ` Ben Hutchings
2011-09-19 16:32         ` Alexander Duyck
2011-09-19 21:00           ` David Miller
2011-09-19 22:27             ` Alexander Duyck
2011-09-19 23:36               ` Jeff Kirsher
2011-09-19 23:42                 ` Stephen Hemminger
2011-09-19 23:47                   ` David Miller
2011-09-20  0:10                   ` Ben Hutchings
2011-09-20 18:59                     ` Andy Gospodarek
2011-09-20 20:23                       ` Neil Horman
2011-09-27 23:45                         ` Ben Hutchings
2011-09-28 11:00                           ` Neil Horman
2011-09-28 15:11                             ` Stephen Hemminger
2011-09-28 17:07                               ` Neil Horman
2011-09-19 20:56         ` David Miller
2011-09-19 20:57   ` David Miller
2011-09-17  8:04 ` [net-next 12/13] igb: split buffer_info into tx_buffer_info and rx_buffer_info Jeff Kirsher
2011-09-17  8:04 ` [net-next 13/13] igb: Consolidate creation of Tx context descriptors into a single function Jeff Kirsher

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