From 1974cc205e63cec4a17a6b3fca31fa4240ded77e Mon Sep 17 00:00:00 2001 From: Ben Hutchings Date: Thu, 29 Jan 2009 18:00:07 +0000 Subject: [PATCH] sfc: Replace stats_enabled flag with a disable count Currently we use a spin-lock to serialise statistics fetches and also to inhibit them for short periods of time, plus a flag to enable/disable statistics fetches for longer periods of time, during online reset. This was apparently insufficient to deal with the several reasons for stats being disabled. Signed-off-by: Ben Hutchings Signed-off-by: David S. Miller --- drivers/net/sfc/efx.c | 33 ++++++++++++++++++++++----------- drivers/net/sfc/efx.h | 2 ++ drivers/net/sfc/falcon.c | 15 +++++++++++---- drivers/net/sfc/net_driver.h | 5 ++--- drivers/net/sfc/sfe4001.c | 15 ++++++++++++++- drivers/net/sfc/tenxpress.c | 12 ++++++------ 6 files changed, 57 insertions(+), 25 deletions(-) diff --git a/drivers/net/sfc/efx.c b/drivers/net/sfc/efx.c index b0e53087bda..ab0e09bf154 100644 --- a/drivers/net/sfc/efx.c +++ b/drivers/net/sfc/efx.c @@ -685,7 +685,7 @@ static int efx_init_port(struct efx_nic *efx) efx->mac_op->reconfigure(efx); efx->port_initialized = true; - efx->stats_enabled = true; + efx_stats_enable(efx); return 0; fail: @@ -734,6 +734,7 @@ static void efx_fini_port(struct efx_nic *efx) if (!efx->port_initialized) return; + efx_stats_disable(efx); efx->phy_op->fini(efx); efx->port_initialized = false; @@ -1360,6 +1361,20 @@ static int efx_net_stop(struct net_device *net_dev) return 0; } +void efx_stats_disable(struct efx_nic *efx) +{ + spin_lock(&efx->stats_lock); + ++efx->stats_disable_count; + spin_unlock(&efx->stats_lock); +} + +void efx_stats_enable(struct efx_nic *efx) +{ + spin_lock(&efx->stats_lock); + --efx->stats_disable_count; + spin_unlock(&efx->stats_lock); +} + /* Context: process, dev_base_lock or RTNL held, non-blocking. */ static struct net_device_stats *efx_net_stats(struct net_device *net_dev) { @@ -1368,12 +1383,12 @@ static struct net_device_stats *efx_net_stats(struct net_device *net_dev) struct net_device_stats *stats = &net_dev->stats; /* Update stats if possible, but do not wait if another thread - * is updating them (or resetting the NIC); slightly stale - * stats are acceptable. + * is updating them or if MAC stats fetches are temporarily + * disabled; slightly stale stats are acceptable. */ if (!spin_trylock(&efx->stats_lock)) return stats; - if (efx->stats_enabled) { + if (!efx->stats_disable_count) { efx->mac_op->update_stats(efx); falcon_update_nic_stats(efx); } @@ -1626,12 +1641,7 @@ void efx_reset_down(struct efx_nic *efx, enum reset_type method, { EFX_ASSERT_RESET_SERIALISED(efx); - /* The net_dev->get_stats handler is quite slow, and will fail - * if a fetch is pending over reset. Serialise against it. */ - spin_lock(&efx->stats_lock); - efx->stats_enabled = false; - spin_unlock(&efx->stats_lock); - + efx_stats_disable(efx); efx_stop_all(efx); mutex_lock(&efx->mac_lock); mutex_lock(&efx->spi_lock); @@ -1682,7 +1692,7 @@ int efx_reset_up(struct efx_nic *efx, enum reset_type method, if (ok) { efx_start_all(efx); - efx->stats_enabled = true; + efx_stats_enable(efx); } return rc; } @@ -1888,6 +1898,7 @@ static int efx_init_struct(struct efx_nic *efx, struct efx_nic_type *type, efx->rx_checksum_enabled = true; spin_lock_init(&efx->netif_stop_lock); spin_lock_init(&efx->stats_lock); + efx->stats_disable_count = 1; mutex_init(&efx->mac_lock); efx->mac_op = &efx_dummy_mac_operations; efx->phy_op = &efx_dummy_phy_operations; diff --git a/drivers/net/sfc/efx.h b/drivers/net/sfc/efx.h index ac201587a16..55d0f131b0e 100644 --- a/drivers/net/sfc/efx.h +++ b/drivers/net/sfc/efx.h @@ -36,6 +36,8 @@ extern void efx_process_channel_now(struct efx_channel *channel); extern void efx_flush_queues(struct efx_nic *efx); /* Ports */ +extern void efx_stats_disable(struct efx_nic *efx); +extern void efx_stats_enable(struct efx_nic *efx); extern void efx_reconfigure_port(struct efx_nic *efx); extern void __efx_reconfigure_port(struct efx_nic *efx); diff --git a/drivers/net/sfc/falcon.c b/drivers/net/sfc/falcon.c index d9412f83a78..d5378e60fcd 100644 --- a/drivers/net/sfc/falcon.c +++ b/drivers/net/sfc/falcon.c @@ -1883,7 +1883,7 @@ static int falcon_reset_macs(struct efx_nic *efx) /* MAC stats will fail whilst the TX fifo is draining. Serialise * the drain sequence with the statistics fetch */ - spin_lock(&efx->stats_lock); + efx_stats_disable(efx); falcon_read(efx, ®, MAC0_CTRL_REG_KER); EFX_SET_OWORD_FIELD(reg, TXFIFO_DRAIN_EN_B0, 1); @@ -1913,7 +1913,7 @@ static int falcon_reset_macs(struct efx_nic *efx) udelay(10); } - spin_unlock(&efx->stats_lock); + efx_stats_enable(efx); /* If we've reset the EM block and the link is up, then * we'll have to kick the XAUI link so the PHY can recover */ @@ -2273,6 +2273,10 @@ int falcon_switch_mac(struct efx_nic *efx) struct efx_mac_operations *old_mac_op = efx->mac_op; efx_oword_t nic_stat; unsigned strap_val; + int rc = 0; + + /* Don't try to fetch MAC stats while we're switching MACs */ + efx_stats_disable(efx); /* Internal loopbacks override the phy speed setting */ if (efx->loopback_mode == LOOPBACK_GMAC) { @@ -2302,13 +2306,16 @@ int falcon_switch_mac(struct efx_nic *efx) } if (old_mac_op == efx->mac_op) - return 0; + goto out; EFX_LOG(efx, "selected %cMAC\n", EFX_IS10G(efx) ? 'X' : 'G'); /* Not all macs support a mac-level link state */ efx->mac_up = true; - return falcon_reset_macs(efx); + rc = falcon_reset_macs(efx); +out: + efx_stats_enable(efx); + return rc; } /* This call is responsible for hooking in the MAC and PHY operations */ diff --git a/drivers/net/sfc/net_driver.h b/drivers/net/sfc/net_driver.h index 8eb411a1c82..e019ad1fb9a 100644 --- a/drivers/net/sfc/net_driver.h +++ b/drivers/net/sfc/net_driver.h @@ -754,8 +754,7 @@ union efx_multicast_hash { * &struct net_device_stats. * @stats_buffer: DMA buffer for statistics * @stats_lock: Statistics update lock. Serialises statistics fetches - * @stats_enabled: Temporarily disable statistics fetches. - * Serialised by @stats_lock + * @stats_disable_count: Nest count for disabling statistics fetches * @mac_op: MAC interface * @mac_address: Permanent MAC address * @phy_type: PHY type @@ -837,7 +836,7 @@ struct efx_nic { struct efx_mac_stats mac_stats; struct efx_buffer stats_buffer; spinlock_t stats_lock; - bool stats_enabled; + unsigned int stats_disable_count; struct efx_mac_operations *mac_op; unsigned char mac_address[ETH_ALEN]; diff --git a/drivers/net/sfc/sfe4001.c b/drivers/net/sfc/sfe4001.c index 853057e87fb..cb25ae5b257 100644 --- a/drivers/net/sfc/sfe4001.c +++ b/drivers/net/sfc/sfe4001.c @@ -235,12 +235,18 @@ static ssize_t set_phy_flash_cfg(struct device *dev, } else if (efx->state != STATE_RUNNING || netif_running(efx->net_dev)) { err = -EBUSY; } else { + /* Reset the PHY, reconfigure the MAC and enable/disable + * MAC stats accordingly. */ efx->phy_mode = new_mode; + if (new_mode & PHY_MODE_SPECIAL) + efx_stats_disable(efx); if (efx->board_info.type == EFX_BOARD_SFE4001) err = sfe4001_poweron(efx); else err = sfn4111t_reset(efx); efx_reconfigure_port(efx); + if (!(new_mode & PHY_MODE_SPECIAL)) + efx_stats_enable(efx); } rtnl_unlock(); @@ -329,6 +335,11 @@ int sfe4001_init(struct efx_nic *efx) efx->board_info.monitor = sfe4001_check_hw; efx->board_info.fini = sfe4001_fini; + if (efx->phy_mode & PHY_MODE_SPECIAL) { + /* PHY won't generate a 156.25 MHz clock and MAC stats fetch + * will fail. */ + efx_stats_disable(efx); + } rc = sfe4001_poweron(efx); if (rc) goto fail_ioexp; @@ -405,8 +416,10 @@ int sfn4111t_init(struct efx_nic *efx) if (rc) goto fail_hwmon; - if (efx->phy_mode & PHY_MODE_SPECIAL) + if (efx->phy_mode & PHY_MODE_SPECIAL) { + efx_stats_disable(efx); sfn4111t_reset(efx); + } return 0; diff --git a/drivers/net/sfc/tenxpress.c b/drivers/net/sfc/tenxpress.c index 412d209d831..f0efd246962 100644 --- a/drivers/net/sfc/tenxpress.c +++ b/drivers/net/sfc/tenxpress.c @@ -370,8 +370,8 @@ static int tenxpress_special_reset(struct efx_nic *efx) /* The XGMAC clock is driven from the SFC7101/SFT9001 312MHz clock, so * a special software reset can glitch the XGMAC sufficiently for stats - * requests to fail. Since we don't often special_reset, just lock. */ - spin_lock(&efx->stats_lock); + * requests to fail. */ + efx_stats_disable(efx); /* Initiate reset */ reg = mdio_clause45_read(efx, efx->mii.phy_id, @@ -386,17 +386,17 @@ static int tenxpress_special_reset(struct efx_nic *efx) rc = mdio_clause45_wait_reset_mmds(efx, TENXPRESS_REQUIRED_DEVS); if (rc < 0) - goto unlock; + goto out; /* Try and reconfigure the device */ rc = tenxpress_init(efx); if (rc < 0) - goto unlock; + goto out; /* Wait for the XGXS state machine to churn */ mdelay(10); -unlock: - spin_unlock(&efx->stats_lock); +out: + efx_stats_enable(efx); return rc; } -- 2.41.1