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Message-ID: <1295471193.11126.90.camel@bwh-desktop>
Date: Wed, 19 Jan 2011 21:06:33 +0000
From: Ben Hutchings <bhutchings@...arflare.com>
To: Tom Herbert <therbert@...gle.com>
Cc: netdev@...r.kernel.org, linux-net-drivers@...arflare.com
Subject: [PATCH net-next-2.6 5/5] sfc: Implement hardware acceleration of
RFS
---
I consider this experimental still, so it's not signed-off.
Ben.
drivers/net/sfc/efx.c | 49 +++++++++++++++++++++-
drivers/net/sfc/efx.h | 16 +++++++
drivers/net/sfc/filter.c | 94 ++++++++++++++++++++++++++++++++++++++++++
drivers/net/sfc/net_driver.h | 3 +
4 files changed, 160 insertions(+), 2 deletions(-)
diff --git a/drivers/net/sfc/efx.c b/drivers/net/sfc/efx.c
index 002bac7..607316d 100644
--- a/drivers/net/sfc/efx.c
+++ b/drivers/net/sfc/efx.c
@@ -21,6 +21,7 @@
#include <linux/ethtool.h>
#include <linux/topology.h>
#include <linux/gfp.h>
+#include <linux/cpu_rmap.h>
#include "net_driver.h"
#include "efx.h"
#include "nic.h"
@@ -307,6 +308,8 @@ static int efx_poll(struct napi_struct *napi, int budget)
channel->irq_mod_score = 0;
}
+ efx_filter_rfs_expire(channel);
+
/* There is no race here; although napi_disable() will
* only wait for napi_complete(), this isn't a problem
* since efx_channel_processed() will have no effect if
@@ -1175,10 +1178,32 @@ static int efx_wanted_channels(void)
return count;
}
+static int
+efx_init_rx_cpu_rmap(struct efx_nic *efx, struct msix_entry *xentries)
+{
+#ifdef CONFIG_RFS_ACCEL
+ int i, rc;
+
+ efx->net_dev->rx_cpu_rmap = alloc_irq_cpu_rmap(efx->n_rx_channels);
+ if (!efx->net_dev->rx_cpu_rmap)
+ return -ENOMEM;
+ for (i = 0; i < efx->n_rx_channels; i++) {
+ rc = irq_cpu_rmap_add(efx->net_dev->rx_cpu_rmap,
+ xentries[i].vector);
+ if (rc) {
+ free_irq_cpu_rmap(efx->net_dev->rx_cpu_rmap);
+ efx->net_dev->rx_cpu_rmap = NULL;
+ return rc;
+ }
+ }
+#endif
+ return 0;
+}
+
/* Probe the number and type of interrupts we are able to obtain, and
* the resulting numbers of channels and RX queues.
*/
-static void efx_probe_interrupts(struct efx_nic *efx)
+static int efx_probe_interrupts(struct efx_nic *efx)
{
int max_channels =
min_t(int, efx->type->phys_addr_channels, EFX_MAX_CHANNELS);
@@ -1220,6 +1245,11 @@ static void efx_probe_interrupts(struct efx_nic *efx)
efx->n_tx_channels = efx->n_channels;
efx->n_rx_channels = efx->n_channels;
}
+ rc = efx_init_rx_cpu_rmap(efx, xentries);
+ if (rc) {
+ pci_disable_msix(efx->pci_dev);
+ return rc;
+ }
for (i = 0; i < n_channels; i++)
efx_get_channel(efx, i)->irq =
xentries[i].vector;
@@ -1253,6 +1283,8 @@ static void efx_probe_interrupts(struct efx_nic *efx)
efx->n_tx_channels = 1;
efx->legacy_irq = efx->pci_dev->irq;
}
+
+ return 0;
}
static void efx_remove_interrupts(struct efx_nic *efx)
@@ -1302,7 +1334,9 @@ static int efx_probe_nic(struct efx_nic *efx)
/* Determine the number of channels and queues by trying to hook
* in MSI-X interrupts. */
- efx_probe_interrupts(efx);
+ rc = efx_probe_interrupts(efx);
+ if (rc)
+ goto fail;
if (efx->n_channels > 1)
get_random_bytes(&efx->rx_hash_key, sizeof(efx->rx_hash_key));
@@ -1317,6 +1351,10 @@ static int efx_probe_nic(struct efx_nic *efx)
efx_init_irq_moderation(efx, tx_irq_mod_usec, rx_irq_mod_usec, true);
return 0;
+
+fail:
+ efx->type->remove(efx);
+ return rc;
}
static void efx_remove_nic(struct efx_nic *efx)
@@ -1849,6 +1887,9 @@ static const struct net_device_ops efx_netdev_ops = {
#ifdef CONFIG_NET_POLL_CONTROLLER
.ndo_poll_controller = efx_netpoll,
#endif
+#ifdef CONFIG_RFS_ACCEL
+ .ndo_rx_flow_steer = efx_filter_rfs,
+#endif
};
static void efx_update_name(struct efx_nic *efx)
@@ -2288,6 +2329,10 @@ static void efx_fini_struct(struct efx_nic *efx)
*/
static void efx_pci_remove_main(struct efx_nic *efx)
{
+#ifdef CONFIG_RFS_ACCEL
+ free_irq_cpu_rmap(efx->net_dev->rx_cpu_rmap);
+ efx->net_dev->rx_cpu_rmap = NULL;
+#endif
efx_nic_fini_interrupt(efx);
efx_fini_channels(efx);
efx_fini_port(efx);
diff --git a/drivers/net/sfc/efx.h b/drivers/net/sfc/efx.h
index d43a7e5..82c6c53 100644
--- a/drivers/net/sfc/efx.h
+++ b/drivers/net/sfc/efx.h
@@ -74,6 +74,22 @@ extern int efx_filter_remove_filter(struct efx_nic *efx,
struct efx_filter_spec *spec);
extern void efx_filter_clear_rx(struct efx_nic *efx,
enum efx_filter_priority priority);
+#ifdef CONFIG_RFS_ACCEL
+extern int efx_filter_rfs(struct net_device *net_dev, const struct sk_buff *skb,
+ u16 rxq_index, u32 flow_id);
+extern unsigned __efx_filter_rfs_expire(struct efx_nic *efx, unsigned quota);
+static inline void efx_filter_rfs_expire(struct efx_channel *channel)
+{
+ if (channel->rfs_filters_added >= 100) {
+ channel->rfs_filters_added -=
+ __efx_filter_rfs_expire(channel->efx, 100);
+ }
+}
+#define efx_filter_rfs_enabled() 1
+#else
+static inline void efx_filter_rfs_expire(struct efx_channel *channel) {}
+#define efx_filter_rfs_enabled() 0
+#endif
/* Channels */
extern void efx_process_channel_now(struct efx_channel *channel);
diff --git a/drivers/net/sfc/filter.c b/drivers/net/sfc/filter.c
index 47a1b79..987cae4 100644
--- a/drivers/net/sfc/filter.c
+++ b/drivers/net/sfc/filter.c
@@ -8,6 +8,7 @@
*/
#include <linux/in.h>
+#include <net/ip.h>
#include "efx.h"
#include "filter.h"
#include "io.h"
@@ -51,6 +52,10 @@ struct efx_filter_table {
struct efx_filter_state {
spinlock_t lock;
struct efx_filter_table table[EFX_FILTER_TABLE_COUNT];
+#ifdef CONFIG_RFS_ACCEL
+ u32 *rps_flow_id;
+ unsigned rps_expire_index;
+#endif
};
/* The filter hash function is LFSR polynomial x^16 + x^3 + 1 of a 32-bit
@@ -567,6 +572,13 @@ int efx_probe_filters(struct efx_nic *efx)
spin_lock_init(&state->lock);
if (efx_nic_rev(efx) >= EFX_REV_FALCON_B0) {
+#ifdef CONFIG_RFS_ACCEL
+ state->rps_flow_id = kcalloc(FR_BZ_RX_FILTER_TBL0_ROWS,
+ sizeof(*state->rps_flow_id),
+ GFP_KERNEL);
+ if (!state->rps_flow_id)
+ goto fail;
+#endif
table = &state->table[EFX_FILTER_TABLE_RX_IP];
table->id = EFX_FILTER_TABLE_RX_IP;
table->offset = FR_BZ_RX_FILTER_TBL0;
@@ -612,5 +624,87 @@ void efx_remove_filters(struct efx_nic *efx)
kfree(state->table[table_id].used_bitmap);
vfree(state->table[table_id].spec);
}
+#ifdef CONFIG_RFS_ACCEL
+ kfree(state->rps_flow_id);
+#endif
kfree(state);
}
+
+#ifdef CONFIG_RFS_ACCEL
+
+int efx_filter_rfs(struct net_device *net_dev, const struct sk_buff *skb,
+ u16 rxq_index, u32 flow_id)
+{
+ struct efx_nic *efx = netdev_priv(net_dev);
+ struct efx_channel *channel;
+ struct efx_filter_state *state = efx->filter_state;
+ struct efx_filter_spec spec;
+ const struct iphdr *ip;
+ const __be16 *ports;
+ int nhoff;
+ int rc;
+
+ nhoff = skb_network_offset(skb);
+
+ if (skb->protocol != htons(ETH_P_IP))
+ return -EPROTONOSUPPORT;
+
+ /* RFS must validate the IP header length before calling us */
+ EFX_BUG_ON_PARANOID(!pskb_may_pull(skb, nhoff + sizeof(*ip)));
+ ip = (const struct iphdr *)(skb->data + nhoff);
+ if (ip->frag_off & htons(IP_MF | IP_OFFSET))
+ return -EPROTONOSUPPORT;
+ EFX_BUG_ON_PARANOID(!pskb_may_pull(skb, nhoff + 4 * ip->ihl + 4));
+ ports = (const __be16 *)(skb->data + nhoff + 4 * ip->ihl);
+
+ efx_filter_init_rx(&spec, EFX_FILTER_PRI_HINT, 0, rxq_index);
+ rc = efx_filter_set_ipv4_full(&spec, ip->protocol,
+ ip->daddr, ports[1], ip->saddr, ports[0]);
+ if (rc)
+ return rc;
+
+ rc = efx_filter_insert_filter(efx, &spec, true);
+ if (rc < 0)
+ return rc;
+
+ /* Remember this so we can check whether to expire the filter later */
+ state->rps_flow_id[rc] = flow_id;
+ channel = efx_get_channel(efx, skb_get_rx_queue(skb));
+ ++channel->rfs_filters_added;
+
+ return rc;
+}
+
+unsigned __efx_filter_rfs_expire(struct efx_nic *efx, unsigned quota)
+{
+ struct efx_filter_state *state = efx->filter_state;
+ struct efx_filter_table *table = &state->table[EFX_FILTER_TABLE_RX_IP];
+ unsigned mask = table->size - 1;
+ unsigned index;
+ unsigned stop;
+
+ if (!spin_trylock_bh(&state->lock))
+ return 0;
+
+ index = state->rps_expire_index;
+ stop = (index + quota) & mask;
+
+ while (index != stop) {
+ if (test_bit(index, table->used_bitmap) &&
+ table->spec[index].priority == EFX_FILTER_PRI_HINT &&
+ rps_may_expire_flow(efx->net_dev,
+ table->spec[index].dmaq_id,
+ state->rps_flow_id[index], index))
+ efx_filter_table_clear_entry(efx, table, index);
+ index = (index + 1) & mask;
+ }
+
+ state->rps_expire_index = stop;
+ if (table->used == 0)
+ efx_filter_table_reset_search_depth(table);
+
+ spin_unlock_bh(&state->lock);
+ return quota;
+}
+
+#endif /* CONFIG_RFS_ACCEL */
diff --git a/drivers/net/sfc/net_driver.h b/drivers/net/sfc/net_driver.h
index 28df866..b92f442 100644
--- a/drivers/net/sfc/net_driver.h
+++ b/drivers/net/sfc/net_driver.h
@@ -358,6 +358,9 @@ struct efx_channel {
unsigned int irq_count;
unsigned int irq_mod_score;
+#ifdef CONFIG_RFS_ACCEL
+ unsigned int rfs_filters_added;
+#endif
int rx_alloc_level;
int rx_alloc_push_pages;
--
1.7.3.4
--
Ben Hutchings, Senior Software Engineer, Solarflare Communications
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.
--
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