Commit 9e77a2b8 authored by Amir Vadai's avatar Amir Vadai Committed by David S. Miller
Browse files

net/mlx4_en: Add Low Latency Socket (LLS) support



Add basic support for LLS.
Signed-off-by: default avatarAmir Vadai <amirv@mellanox.com>
Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent dc3d807d
......@@ -139,6 +139,7 @@ int mlx4_en_activate_cq(struct mlx4_en_priv *priv, struct mlx4_en_cq *cq,
if (!cq->is_tx) {
netif_napi_add(cq->dev, &cq->napi, mlx4_en_poll_rx_cq, 64);
napi_hash_add(&cq->napi);
napi_enable(&cq->napi);
}
......@@ -162,6 +163,8 @@ void mlx4_en_deactivate_cq(struct mlx4_en_priv *priv, struct mlx4_en_cq *cq)
{
if (!cq->is_tx) {
napi_disable(&cq->napi);
napi_hash_del(&cq->napi);
synchronize_rcu();
netif_napi_del(&cq->napi);
}
......
......@@ -38,6 +38,7 @@
#include <linux/slab.h>
#include <linux/hash.h>
#include <net/ip.h>
#include <net/ll_poll.h>
#include <linux/mlx4/driver.h>
#include <linux/mlx4/device.h>
......@@ -67,6 +68,30 @@ int mlx4_en_setup_tc(struct net_device *dev, u8 up)
return 0;
}
#ifdef CONFIG_NET_LL_RX_POLL
/* must be called with local_bh_disable()d */
static int mlx4_en_low_latency_recv(struct napi_struct *napi)
{
struct mlx4_en_cq *cq = container_of(napi, struct mlx4_en_cq, napi);
struct net_device *dev = cq->dev;
struct mlx4_en_priv *priv = netdev_priv(dev);
struct mlx4_en_rx_ring *rx_ring = &priv->rx_ring[cq->ring];
int done;
if (!priv->port_up)
return LL_FLUSH_FAILED;
if (!mlx4_en_cq_lock_poll(cq))
return LL_FLUSH_BUSY;
done = mlx4_en_process_rx_cq(dev, cq, 4);
mlx4_en_cq_unlock_poll(cq);
return done;
}
#endif /* CONFIG_NET_LL_RX_POLL */
#ifdef CONFIG_RFS_ACCEL
struct mlx4_en_filter {
......@@ -1445,6 +1470,8 @@ int mlx4_en_start_port(struct net_device *dev)
for (i = 0; i < priv->rx_ring_num; i++) {
cq = &priv->rx_cq[i];
mlx4_en_cq_init_lock(cq);
err = mlx4_en_activate_cq(priv, cq, i);
if (err) {
en_err(priv, "Failed activating Rx CQ\n");
......@@ -1694,10 +1721,19 @@ void mlx4_en_stop_port(struct net_device *dev, int detach)
/* Free RX Rings */
for (i = 0; i < priv->rx_ring_num; i++) {
struct mlx4_en_cq *cq = &priv->rx_cq[i];
local_bh_disable();
while (!mlx4_en_cq_lock_napi(cq)) {
pr_info("CQ %d locked\n", i);
mdelay(1);
}
local_bh_enable();
mlx4_en_deactivate_rx_ring(priv, &priv->rx_ring[i]);
while (test_bit(NAPI_STATE_SCHED, &priv->rx_cq[i].napi.state))
while (test_bit(NAPI_STATE_SCHED, &cq->napi.state))
msleep(1);
mlx4_en_deactivate_cq(priv, &priv->rx_cq[i]);
mlx4_en_deactivate_cq(priv, cq);
}
/* close port*/
......@@ -2090,6 +2126,9 @@ static const struct net_device_ops mlx4_netdev_ops = {
#ifdef CONFIG_RFS_ACCEL
.ndo_rx_flow_steer = mlx4_en_filter_rfs,
#endif
#ifdef CONFIG_NET_LL_RX_POLL
.ndo_ll_poll = mlx4_en_low_latency_recv,
#endif
};
static const struct net_device_ops mlx4_netdev_ops_master = {
......
......@@ -31,6 +31,7 @@
*
*/
#include <net/ll_poll.h>
#include <linux/mlx4/cq.h>
#include <linux/slab.h>
#include <linux/mlx4/qp.h>
......@@ -656,8 +657,11 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
* - DIX Ethernet (type interpretation)
* - TCP/IP (v4)
* - without IP options
* - not an IP fragment */
if (dev->features & NETIF_F_GRO) {
* - not an IP fragment
* - no LLS polling in progress
*/
if (!mlx4_en_cq_ll_polling(cq) &&
(dev->features & NETIF_F_GRO)) {
struct sk_buff *gro_skb = napi_get_frags(&cq->napi);
if (!gro_skb)
goto next;
......@@ -737,6 +741,8 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
timestamp);
}
skb_mark_ll(skb, &cq->napi);
/* Push it up the stack */
netif_receive_skb(skb);
......@@ -781,8 +787,13 @@ int mlx4_en_poll_rx_cq(struct napi_struct *napi, int budget)
struct mlx4_en_priv *priv = netdev_priv(dev);
int done;
if (!mlx4_en_cq_lock_napi(cq))
return budget;
done = mlx4_en_process_rx_cq(dev, cq, budget);
mlx4_en_cq_unlock_napi(cq);
/* If we used up all the quota - we're probably not done yet... */
if (done == budget)
INC_PERF_COUNTER(priv->pstats.napi_quota);
......
......@@ -310,6 +310,19 @@ struct mlx4_en_cq {
u16 moder_cnt;
struct mlx4_cqe *buf;
#define MLX4_EN_OPCODE_ERROR 0x1e
#ifdef CONFIG_NET_LL_RX_POLL
unsigned int state;
#define MLX4_EN_CQ_STATE_IDLE 0
#define MLX4_EN_CQ_STATE_NAPI 1 /* NAPI owns this CQ */
#define MLX4_EN_CQ_STATE_POLL 2 /* poll owns this CQ */
#define MLX4_CQ_LOCKED (MLX4_EN_CQ_STATE_NAPI | MLX4_EN_CQ_STATE_POLL)
#define MLX4_EN_CQ_STATE_NAPI_YIELD 4 /* NAPI yielded this CQ */
#define MLX4_EN_CQ_STATE_POLL_YIELD 8 /* poll yielded this CQ */
#define CQ_YIELD (MLX4_EN_CQ_STATE_NAPI_YIELD | MLX4_EN_CQ_STATE_POLL_YIELD)
#define CQ_USER_PEND (MLX4_EN_CQ_STATE_POLL | MLX4_EN_CQ_STATE_POLL_YIELD)
spinlock_t poll_lock; /* protects from LLS/napi conflicts */
#endif /* CONFIG_NET_LL_RX_POLL */
};
struct mlx4_en_port_profile {
......@@ -562,6 +575,114 @@ struct mlx4_mac_entry {
struct rcu_head rcu;
};
#ifdef CONFIG_NET_LL_RX_POLL
static inline void mlx4_en_cq_init_lock(struct mlx4_en_cq *cq)
{
spin_lock_init(&cq->poll_lock);
cq->state = MLX4_EN_CQ_STATE_IDLE;
}
/* called from the device poll rutine to get ownership of a cq */
static inline bool mlx4_en_cq_lock_napi(struct mlx4_en_cq *cq)
{
int rc = true;
spin_lock(&cq->poll_lock);
if (cq->state & MLX4_CQ_LOCKED) {
WARN_ON(cq->state & MLX4_EN_CQ_STATE_NAPI);
cq->state |= MLX4_EN_CQ_STATE_NAPI_YIELD;
rc = false;
} else
/* we don't care if someone yielded */
cq->state = MLX4_EN_CQ_STATE_NAPI;
spin_unlock(&cq->poll_lock);
return rc;
}
/* returns true is someone tried to get the cq while napi had it */
static inline bool mlx4_en_cq_unlock_napi(struct mlx4_en_cq *cq)
{
int rc = false;
spin_lock(&cq->poll_lock);
WARN_ON(cq->state & (MLX4_EN_CQ_STATE_POLL |
MLX4_EN_CQ_STATE_NAPI_YIELD));
if (cq->state & MLX4_EN_CQ_STATE_POLL_YIELD)
rc = true;
cq->state = MLX4_EN_CQ_STATE_IDLE;
spin_unlock(&cq->poll_lock);
return rc;
}
/* called from mlx4_en_low_latency_poll() */
static inline bool mlx4_en_cq_lock_poll(struct mlx4_en_cq *cq)
{
int rc = true;
spin_lock_bh(&cq->poll_lock);
if ((cq->state & MLX4_CQ_LOCKED)) {
struct net_device *dev = cq->dev;
struct mlx4_en_priv *priv = netdev_priv(dev);
struct mlx4_en_rx_ring *rx_ring = &priv->rx_ring[cq->ring];
cq->state |= MLX4_EN_CQ_STATE_POLL_YIELD;
rc = false;
} else
/* preserve yield marks */
cq->state |= MLX4_EN_CQ_STATE_POLL;
spin_unlock_bh(&cq->poll_lock);
return rc;
}
/* returns true if someone tried to get the cq while it was locked */
static inline bool mlx4_en_cq_unlock_poll(struct mlx4_en_cq *cq)
{
int rc = false;
spin_lock_bh(&cq->poll_lock);
WARN_ON(cq->state & (MLX4_EN_CQ_STATE_NAPI));
if (cq->state & MLX4_EN_CQ_STATE_POLL_YIELD)
rc = true;
cq->state = MLX4_EN_CQ_STATE_IDLE;
spin_unlock_bh(&cq->poll_lock);
return rc;
}
/* true if a socket is polling, even if it did not get the lock */
static inline bool mlx4_en_cq_ll_polling(struct mlx4_en_cq *cq)
{
WARN_ON(!(cq->state & MLX4_CQ_LOCKED));
return cq->state & CQ_USER_PEND;
}
#else
static inline void mlx4_en_cq_init_lock(struct mlx4_en_cq *cq)
{
}
static inline bool mlx4_en_cq_lock_napi(struct mlx4_en_cq *cq)
{
return true;
}
static inline bool mlx4_en_cq_unlock_napi(struct mlx4_en_cq *cq)
{
return false;
}
static inline bool mlx4_en_cq_lock_poll(struct mlx4_en_cq *cq)
{
return false;
}
static inline bool mlx4_en_cq_unlock_poll(struct mlx4_en_cq *cq)
{
return false;
}
static inline bool mlx4_en_cq_ll_polling(struct mlx4_en_cq *cq)
{
return false;
}
#endif /* CONFIG_NET_LL_RX_POLL */
#define MLX4_EN_WOL_DO_MODIFY (1ULL << 63)
void mlx4_en_update_loopback_state(struct net_device *dev,
......
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