[NET-NEXT PATCH 16/18] igb: add support for in kernel LRO

Jeff Kirsher
2008-06-27T18:07:49Z

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

This patch adds support for the use of the inet_lro module to provide
software LRO support.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
---

drivers/net/Kconfig | 9 +++
drivers/net/igb/e1000_82575.h | 2 +
drivers/net/igb/igb.h | 16 ++++++
drivers/net/igb/igb_ethtool.c | 17 ++++++
drivers/net/igb/igb_main.c | 115 +++++++++++++++++++++++++++++++++++++----
5 files changed, 149 insertions(+), 10 deletions(-)

diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
index 287d087..d782b28 100644
--- a/drivers/net/Kconfig
+++ b/drivers/net/Kconfig
@@ -2059,6 +2059,15 @@ config IGB
To compile this driver as a module, choose M here. The module
will be called igb.

+config IGB_LRO
+ bool "Use software LRO"
+ depends on IGB && INET
+ select INET_LRO
+ ---help---
+ Say Y here if you want to use large receive offload.
+
+ If in doubt, say N.
+
source "drivers/net/ixp2000/Kconfig"

config MYRI_SBUS
diff --git a/drivers/net/igb/e1000_82575.h b/drivers/net/igb/e1000_82575.h
index d273236..2f848e5 100644
--- a/drivers/net/igb/e1000_82575.h
+++ b/drivers/net/igb/e1000_82575.h
@@ -99,6 +99,8 @@ union e1000_adv_rx_desc {
/* RSS Hash results */

/* RSS Packet Types as indicated in the receive descriptor */
+#define E1000_RXDADV_PKTTYPE_IPV4 0x00000010 /* IPV4 hdr present */
+#define E1000_RXDADV_PKTTYPE_TCP 0x00000100 /* TCP hdr present */

/* Transmit Descriptor - Advanced */
union e1000_adv_tx_desc {
diff --git a/drivers/net/igb/igb.h b/drivers/net/igb/igb.h
index da7bbaf..270650f 100644
--- a/drivers/net/igb/igb.h
+++ b/drivers/net/igb/igb.h
@@ -36,6 +36,12 @@

struct igb_adapter;

+#ifdef CONFIG_IGB_LRO
+#include <linux/inet_lro.h>
+#define MAX_LRO_AGGR 32
+#define MAX_LRO_DESCRIPTORS 8
+#endif
+
/* Interrupt defines */
#define IGB_MAX_TX_CLEAN 72

@@ -167,6 +173,10 @@ struct igb_ring {
int no_itr_adjust;
struct igb_queue_stats rx_stats;
struct napi_struct napi;
+#ifdef CONFIG_IGB_LRO
+ struct net_lro_mgr lro_mgr;
+ bool lro_used;
+#endif
};
};

@@ -273,6 +283,12 @@ struct igb_adapter {
#ifdef CONFIG_NETDEVICES_MULTIQUEUE
struct igb_ring *multi_tx_table[IGB_MAX_TX_QUEUES];
#endif /* CONFIG_NETDEVICES_MULTIQUEUE */
+#ifdef CONFIG_IGB_LRO
+ unsigned int lro_max_aggr;
+ unsigned int lro_aggregated;
+ unsigned int lro_flushed;
+ unsigned int lro_no_desc;
+#endif
};

#define IGB_FLAG_HAS_MSI (1 << 0)
diff --git a/drivers/net/igb/igb_ethtool.c b/drivers/net/igb/igb_ethtool.c
index ef209b5..7db1830 100644
--- a/drivers/net/igb/igb_ethtool.c
+++ b/drivers/net/igb/igb_ethtool.c
@@ -93,6 +93,11 @@ static const struct igb_stats igb_gstrings_stats[] = {
{ "tx_smbus", IGB_STAT(stats.mgptc) },
{ "rx_smbus", IGB_STAT(stats.mgprc) },
{ "dropped_smbus", IGB_STAT(stats.mgpdc) },
+#ifdef CONFIG_IGB_LRO
+ { "lro_aggregated", IGB_STAT(lro_aggregated) },
+ { "lro_flushed", IGB_STAT(lro_flushed) },
+ { "lro_no_desc", IGB_STAT(lro_no_desc) },
+#endif
};

#define IGB_QUEUE_STATS_LEN \
@@ -1917,6 +1922,18 @@ static void igb_get_ethtool_stats(struct net_device *netdev,
int stat_count = sizeof(struct igb_queue_stats) / sizeof(u64);
int j;
int i;
+#ifdef CONFIG_IGB_LRO
+ int aggregated = 0, flushed = 0, no_desc = 0;
+
+ for (i = 0; i < adapter->num_rx_queues; i++) {
+ aggregated += adapter->rx_ring[i].lro_mgr.stats.aggregated;
+ flushed += adapter->rx_ring[i].lro_mgr.stats.flushed;
+ no_desc += adapter->rx_ring[i].lro_mgr.stats.no_desc;
+ }
+ adapter->lro_aggregated = aggregated;
+ adapter->lro_flushed = flushed;
+ adapter->lro_no_desc = no_desc;
+#endif

igb_update_stats(adapter);
for (i = 0; i < IGB_GLOBAL_STATS_LEN; i++) {
diff --git a/drivers/net/igb/igb_main.c b/drivers/net/igb/igb_main.c
index 2b5dbc7..c43f287 100644
--- a/drivers/net/igb/igb_main.c
+++ b/drivers/net/igb/igb_main.c
@@ -116,6 +116,9 @@ static bool igb_clean_tx_irq(struct igb_ring *);
static int igb_poll(struct napi_struct *, int);
static bool igb_clean_rx_irq_adv(struct igb_ring *, int *, int);
static void igb_alloc_rx_buffers_adv(struct igb_ring *, int);
+#ifdef CONFIG_IGB_LRO
+static int igb_get_skb_hdr(struct sk_buff *skb, void **, void **, u64 *, void *);
+#endif
static int igb_ioctl(struct net_device *, struct ifreq *, int cmd);
static void igb_tx_timeout(struct net_device *);
static void igb_reset_task(struct work_struct *);
@@ -1107,6 +1110,10 @@ static int __devinit igb_probe(struct pci_dev *pdev,
netdev->features |= NETIF_F_TSO;
netdev->features |= NETIF_F_TSO6;

+#ifdef CONFIG_IGB_LRO
+ netdev->features |= NETIF_F_LRO;
+#endif
+
netdev->vlan_features |= NETIF_F_TSO;
netdev->vlan_features |= NETIF_F_TSO6;
netdev->vlan_features |= NETIF_F_HW_CSUM;
@@ -1678,6 +1685,14 @@ int igb_setup_rx_resources(struct igb_adapter *adapter,
struct pci_dev *pdev = adapter->pdev;
int size, desc_len;

+#ifdef CONFIG_IGB_LRO
+ size = sizeof(struct net_lro_desc) * MAX_LRO_DESCRIPTORS;
+ rx_ring->lro_mgr.lro_arr = vmalloc(size);
+ if (!rx_ring->lro_mgr.lro_arr)
+ goto err;
+ memset(rx_ring->lro_mgr.lro_arr, 0, size);
+#endif
+
size = sizeof(struct igb_buffer) * rx_ring->count;
rx_ring->buffer_info = vmalloc(size);
if (!rx_ring->buffer_info)
@@ -1704,6 +1719,10 @@ int igb_setup_rx_resources(struct igb_adapter *adapter,
return 0;

err:
+#ifdef CONFIG_IGB_LRO
+ vfree(rx_ring->lro_mgr.lro_arr);
+ rx_ring->lro_mgr.lro_arr = NULL;
+#endif
vfree(rx_ring->buffer_info);
dev_err(&adapter->pdev->dev, "Unable to allocate memory for "
"the receive descriptor ring\n");
@@ -1867,6 +1886,16 @@ static void igb_configure_rx(struct igb_adapter *adapter)
rxdctl |= IGB_RX_HTHRESH << 8;
rxdctl |= IGB_RX_WTHRESH << 16;
wr32(E1000_RXDCTL(i), rxdctl);
+#ifdef CONFIG_IGB_LRO
+ /* Intitial LRO Settings */
+ ring->lro_mgr.max_aggr = MAX_LRO_AGGR;
+ ring->lro_mgr.max_desc = MAX_LRO_DESCRIPTORS;
+ ring->lro_mgr.get_skb_header = igb_get_skb_hdr;
+ ring->lro_mgr.features = LRO_F_NAPI | LRO_F_EXTRACT_VLAN_ID;
+ ring->lro_mgr.dev = adapter->netdev;
+ ring->lro_mgr.ip_summed = CHECKSUM_UNNECESSARY;
+ ring->lro_mgr.ip_summed_aggr = CHECKSUM_UNNECESSARY;
+#endif
}

if (adapter->num_rx_queues > 1) {
@@ -2058,6 +2087,11 @@ static void igb_free_rx_resources(struct igb_ring *rx_ring)
vfree(rx_ring->buffer_info);
rx_ring->buffer_info = NULL;

+#ifdef CONFIG_IGB_LRO
+ vfree(rx_ring->lro_mgr.lro_arr);
+ rx_ring->lro_mgr.lro_arr = NULL;
+#endif
+
pci_free_consistent(pdev, rx_ring->size, rx_ring->desc, rx_ring->dma);

rx_ring->desc = NULL;
@@ -3708,23 +3742,77 @@ done_cleaning:
return retval;
}

+#ifdef CONFIG_IGB_LRO
+ /**
+ * igb_get_skb_hdr - helper function for LRO header processing
+ * @skb: pointer to sk_buff to be added to LRO packet
+ * @iphdr: pointer to ip header structure
+ * @tcph: pointer to tcp header structure
+ * @hdr_flags: pointer to header flags
+ * @priv: pointer to the receive descriptor for the current sk_buff
+ **/
+static int igb_get_skb_hdr(struct sk_buff *skb, void **iphdr, void **tcph,
+ u64 *hdr_flags, void *priv)
+{
+ union e1000_adv_rx_desc *rx_desc = priv;
+ u16 pkt_type = rx_desc->wb.lower.lo_dword.pkt_info &
+ (E1000_RXDADV_PKTTYPE_IPV4 | E1000_RXDADV_PKTTYPE_TCP);
+
+ /* Verify that this is a valid IPv4 TCP packet */
+ if (pkt_type != (E1000_RXDADV_PKTTYPE_IPV4 |
+ E1000_RXDADV_PKTTYPE_TCP))
+ return -1;
+
+ /* Set network headers */
+ skb_reset_network_header(skb);
+ skb_set_transport_header(skb, ip_hdrlen(skb));
+ *iphdr = ip_hdr(skb);
+ *tcph = tcp_hdr(skb);
+ *hdr_flags = LRO_IPV4 | LRO_TCP;
+
+ return 0;
+
+}
+#endif /* CONFIG_IGB_LRO */

/**
* igb_receive_skb - helper function to handle rx indications
- * @adapter: board private structure
+ * @ring: pointer to receive ring receving this packet
* @status: descriptor status field as written by hardware
* @vlan: descriptor vlan field as written by hardware (no le/be conversion)
* @skb: pointer to sk_buff to be indicated to stack
**/
-static void igb_receive_skb(struct igb_adapter *adapter, u8 status, __le16 vlan,
- struct sk_buff *skb)
+static void igb_receive_skb(struct igb_ring *ring, u8 status,
+ union e1000_adv_rx_desc * rx_desc,
+ struct sk_buff *skb)
{
- if (adapter->vlgrp && (status & E1000_RXD_STAT_VP))
- vlan_hwaccel_receive_skb(skb, adapter->vlgrp,
- le16_to_cpu(vlan) &
- E1000_RXD_SPC_VLAN_MASK);
- else
- netif_receive_skb(skb);
+ struct igb_adapter * adapter = ring->adapter;
+ bool vlan_extracted = (adapter->vlgrp && (status & E1000_RXD_STAT_VP));
+
+#ifdef CONFIG_IGB_LRO
+ if (adapter->netdev->features & NETIF_F_LRO &&
+ skb->ip_summed == CHECKSUM_UNNECESSARY) {
+ if (vlan_extracted)
+ lro_vlan_hwaccel_receive_skb(&ring->lro_mgr, skb,
+ adapter->vlgrp,
+ le16_to_cpu(rx_desc->wb.upper.vlan) &
+ E1000_RXD_SPC_VLAN_MASK,
+ rx_desc);
+ else
+ lro_receive_skb(&ring->lro_mgr,skb, rx_desc);
+ ring->lro_used = 1;
+ } else {
+#endif
+ if (vlan_extracted)
+ vlan_hwaccel_receive_skb(skb, adapter->vlgrp,
+ le16_to_cpu(rx_desc->wb.upper.vlan) &
+ E1000_RXD_SPC_VLAN_MASK);
+ else
+
+ netif_receive_skb(skb);
+#ifdef CONFIG_IGB_LRO
+ }
+#endif
}

@@ -3857,7 +3945,7 @@ send_up:

skb->protocol = eth_type_trans(skb, netdev);

- igb_receive_skb(adapter, staterr, rx_desc->wb.upper.vlan, skb);
+ igb_receive_skb(rx_ring, staterr, rx_desc, skb);

netdev->last_rx = jiffies;

@@ -3880,6 +3968,13 @@ next_desc:
rx_ring->next_to_clean = i;
cleaned_count = IGB_DESC_UNUSED(rx_ring);

+#ifdef CONFIG_IGB_LRO
+ if (rx_ring->lro_used) {
+ lro_flush_all(&rx_ring->lro_mgr);
+ rx_ring->lro_used = 0;
+ }
+#endif
+
if (cleaned_count)
igb_alloc_rx_buffers_adv(rx_ring, cleaned_count);