Re: [PATCH] net: mv643xx_eth: Add GRO support

From: Willy Tarreau
Date: Thu Apr 11 2013 - 14:03:29 EST


On Thu, Apr 11, 2013 at 10:59:15AM -0700, Eric Dumazet wrote:
> On Thu, 2013-04-11 at 19:51 +0200, Willy Tarreau wrote:
>
> > Eric provided me with one such experimental patch in the past for this
> > driver. It worked for me but we never tried to clean it up to propose
> > it for inclusion.
> >
> > If anyone is interested, I might still have it in experimental shape.
>
> We are interested a lot ;)

Just found it in one of my local branches :-)

Here it is. It was experimental. At first glance, I'm seeing it does not
remove NETIF_F_LRO as we used it for experimentation only, but that's
a trivial thing to fix.

Original work by you Eric, tested by me on 3.6.


diff --git a/drivers/net/ethernet/marvell/mv643xx_eth.c b/drivers/net/ethernet/marvell/mv643xx_eth.c
index ea2cedc..81a6cb0 100644
--- a/drivers/net/ethernet/marvell/mv643xx_eth.c
+++ b/drivers/net/ethernet/marvell/mv643xx_eth.c
@@ -55,9 +55,9 @@
#include <linux/mv643xx_eth.h>
#include <linux/io.h>
#include <linux/types.h>
-#include <linux/inet_lro.h>
#include <linux/slab.h>
#include <linux/clk.h>
+#include <linux/interrupt.h>

static char mv643xx_eth_driver_name[] = "mv643xx_eth";
static char mv643xx_eth_driver_version[] = "1.4";
@@ -343,12 +343,6 @@ struct mib_counters {
u32 rx_overrun;
};

-struct lro_counters {
- u32 lro_aggregated;
- u32 lro_flushed;
- u32 lro_no_desc;
-};
-
struct rx_queue {
int index;

@@ -363,8 +357,6 @@ struct rx_queue {
int rx_desc_area_size;
void **rx_data;
unsigned int frag_size;
- struct net_lro_mgr lro_mgr;
- struct net_lro_desc lro_arr[8];
};

struct tx_queue {
@@ -400,8 +392,6 @@ struct mv643xx_eth_private {
spinlock_t mib_counters_lock;
struct mib_counters mib_counters;

- struct lro_counters lro_counters;
-
struct work_struct tx_timeout_task;

struct napi_struct napi;
@@ -533,33 +523,6 @@ static void txq_maybe_wake(struct tx_queue *txq)
}


-/* rx napi ******************************************************************/
-static int
-mv643xx_get_skb_header(struct sk_buff *skb, void **iphdr, void **tcph,
- u64 *hdr_flags, void *priv)
-{
- unsigned long cmd_sts = (unsigned long)priv;
-
- /*
- * Make sure that this packet is Ethernet II, is not VLAN
- * tagged, is IPv4, has a valid IP header, and is TCP.
- */
- if ((cmd_sts & (RX_IP_HDR_OK | RX_PKT_IS_IPV4 |
- RX_PKT_IS_ETHERNETV2 | RX_PKT_LAYER4_TYPE_MASK |
- RX_PKT_IS_VLAN_TAGGED)) !=
- (RX_IP_HDR_OK | RX_PKT_IS_IPV4 |
- RX_PKT_IS_ETHERNETV2 | RX_PKT_LAYER4_TYPE_TCP_IPV4))
- return -1;
-
- 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;
-}
-
static void mv_frag_free(const struct rx_queue *rxq, void *data)
{
if (rxq->frag_size)
@@ -568,14 +531,12 @@ static void mv_frag_free(const struct rx_queue *rxq, void *data)
kfree(data);
}

-static int rxq_process(struct rx_queue *rxq, int budget)
+static int rxq_process(struct napi_struct *napi, struct rx_queue *rxq, int budget)
{
struct mv643xx_eth_private *mp = rxq_to_mp(rxq);
struct net_device_stats *stats = &mp->dev->stats;
- int lro_flush_needed;
int rx;

- lro_flush_needed = 0;
rx = 0;
while (rx < budget && rxq->rx_desc_count) {
struct rx_desc *rx_desc;
@@ -646,12 +607,7 @@ static int rxq_process(struct rx_queue *rxq, int budget)
skb->ip_summed = CHECKSUM_UNNECESSARY;
skb->protocol = eth_type_trans(skb, mp->dev);

- if (skb->dev->features & NETIF_F_LRO &&
- skb->ip_summed == CHECKSUM_UNNECESSARY) {
- lro_receive_skb(&rxq->lro_mgr, skb, (void *)cmd_sts);
- lro_flush_needed = 1;
- } else
- netif_receive_skb(skb);
+ napi_gro_receive(napi, skb);

continue;

@@ -671,9 +627,6 @@ err:
dev_kfree_skb(skb);
}

- if (lro_flush_needed)
- lro_flush_all(&rxq->lro_mgr);
-
if (rx < budget)
mp->work_rx &= ~(1 << rxq->index);

@@ -723,7 +676,6 @@ static int rxq_refill(struct rx_queue *rxq, int budget)
rxq->rx_data[rx] = data;
wmb();
rx_desc->cmd_sts = BUFFER_OWNED_BY_DMA | RX_ENABLE_INTERRUPT;
-
}

if (refilled < budget)
@@ -1214,26 +1166,6 @@ static struct net_device_stats *mv643xx_eth_get_stats(struct net_device *dev)
return stats;
}

-static void mv643xx_eth_grab_lro_stats(struct mv643xx_eth_private *mp)
-{
- u32 lro_aggregated = 0;
- u32 lro_flushed = 0;
- u32 lro_no_desc = 0;
- int i;
-
- for (i = 0; i < mp->rxq_count; i++) {
- struct rx_queue *rxq = mp->rxq + i;
-
- lro_aggregated += rxq->lro_mgr.stats.aggregated;
- lro_flushed += rxq->lro_mgr.stats.flushed;
- lro_no_desc += rxq->lro_mgr.stats.no_desc;
- }
-
- mp->lro_counters.lro_aggregated = lro_aggregated;
- mp->lro_counters.lro_flushed = lro_flushed;
- mp->lro_counters.lro_no_desc = lro_no_desc;
-}
-
static inline u32 mib_read(struct mv643xx_eth_private *mp, int offset)
{
return rdl(mp, MIB_COUNTERS(mp->port_num) + offset);
@@ -1397,10 +1329,6 @@ struct mv643xx_eth_stats {
{ #m, FIELD_SIZEOF(struct mib_counters, m), \
-1, offsetof(struct mv643xx_eth_private, mib_counters.m) }

-#define LROSTAT(m) \
- { #m, FIELD_SIZEOF(struct lro_counters, m), \
- -1, offsetof(struct mv643xx_eth_private, lro_counters.m) }
-
static const struct mv643xx_eth_stats mv643xx_eth_stats[] = {
SSTAT(rx_packets),
SSTAT(tx_packets),
@@ -1442,9 +1370,6 @@ static const struct mv643xx_eth_stats mv643xx_eth_stats[] = {
MIBSTAT(late_collision),
MIBSTAT(rx_discard),
MIBSTAT(rx_overrun),
- LROSTAT(lro_aggregated),
- LROSTAT(lro_flushed),
- LROSTAT(lro_no_desc),
};

static int
@@ -1642,7 +1567,6 @@ static void mv643xx_eth_get_ethtool_stats(struct net_device *dev,

mv643xx_eth_get_stats(dev);
mib_counters_update(mp);
- mv643xx_eth_grab_lro_stats(mp);

for (i = 0; i < ARRAY_SIZE(mv643xx_eth_stats); i++) {
const struct mv643xx_eth_stats *stat;
@@ -1915,19 +1839,6 @@ static int rxq_init(struct mv643xx_eth_private *mp, int index)
nexti * sizeof(struct rx_desc);
}

- rxq->lro_mgr.dev = mp->dev;
- memset(&rxq->lro_mgr.stats, 0, sizeof(rxq->lro_mgr.stats));
- rxq->lro_mgr.features = LRO_F_NAPI;
- rxq->lro_mgr.ip_summed = CHECKSUM_UNNECESSARY;
- rxq->lro_mgr.ip_summed_aggr = CHECKSUM_UNNECESSARY;
- rxq->lro_mgr.max_desc = ARRAY_SIZE(rxq->lro_arr);
- rxq->lro_mgr.max_aggr = 32;
- rxq->lro_mgr.frag_align_pad = 0;
- rxq->lro_mgr.lro_arr = rxq->lro_arr;
- rxq->lro_mgr.get_skb_header = mv643xx_get_skb_header;
-
- memset(&rxq->lro_arr, 0, sizeof(rxq->lro_arr));
-
return 0;


@@ -2192,7 +2103,7 @@ static int mv643xx_eth_poll(struct napi_struct *napi, int budget)
work_done += txq_reclaim(mp->txq + queue, work_tbd, 0);
txq_maybe_wake(mp->txq + queue);
} else if (mp->work_rx & queue_mask) {
- work_done += rxq_process(mp->rxq + queue, work_tbd);
+ work_done += rxq_process(napi, mp->rxq + queue, work_tbd);
} else if (!mp->oom && (mp->work_rx_refill & queue_mask)) {
work_done += rxq_refill(mp->rxq + queue, work_tbd);
} else {

Regards,
Willy

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