From 623b9988bfd146a438e55816dbfdf8f9a5290dd5 Mon Sep 17 00:00:00 2001 From: Edward Cree Date: Tue, 29 Sep 2020 22:25:24 +0200 Subject: [PATCH] net: sfc: Replace in_interrupt() usage efx_ef10_try_update_nic_stats_vf() used in_interrupt() to figure out whether it is safe to sleep (for MCDI) or not. The only caller from which it was not is efx_net_stats(), which can be invoked under dev_base_lock from net-sysfs::netstat_show(). So add a new update_stats_atomic() method to struct efx_nic_type, and call it from efx_net_stats(), removing the need for efx_ef10_try_update_nic_stats_vf() to behave differently for this case (which it wasn't doing correctly anyway). For all nic_types other than EF10 VF, this method is NULL so the the regular update_stats() methods are invoked , which are happy with being called from atomic contexts. Fixes: f00bf2305cab ("sfc: don't update stats on VF when called in atomic context") Reported-by: Sebastian Andrzej Siewior Signed-off-by: Edward Cree Signed-off-by: Thomas Gleixner Reviewed-by: Martin Habets Signed-off-by: David S. Miller --- drivers/net/ethernet/sfc/ef10.c | 22 +++++++++++++--------- drivers/net/ethernet/sfc/efx_common.c | 2 +- drivers/net/ethernet/sfc/net_driver.h | 5 +++++ drivers/net/ethernet/sfc/nic_common.h | 7 +++++++ 4 files changed, 26 insertions(+), 10 deletions(-) diff --git a/drivers/net/ethernet/sfc/ef10.c b/drivers/net/ethernet/sfc/ef10.c index c9df2e96ebe4..b702ba5986dc 100644 --- a/drivers/net/ethernet/sfc/ef10.c +++ b/drivers/net/ethernet/sfc/ef10.c @@ -1871,15 +1871,6 @@ static int efx_ef10_try_update_nic_stats_vf(struct efx_nic *efx) spin_unlock_bh(&efx->stats_lock); - if (in_interrupt()) { - /* If in atomic context, cannot update stats. Just update the - * software stats and return so the caller can continue. - */ - spin_lock_bh(&efx->stats_lock); - efx_update_sw_stats(efx, stats); - return 0; - } - efx_ef10_get_stat_mask(efx, mask); rc = efx_nic_alloc_buffer(efx, &stats_buf, dma_len, GFP_ATOMIC); @@ -1938,6 +1929,18 @@ static size_t efx_ef10_update_stats_vf(struct efx_nic *efx, u64 *full_stats, return efx_ef10_update_stats_common(efx, full_stats, core_stats); } +static size_t efx_ef10_update_stats_atomic_vf(struct efx_nic *efx, u64 *full_stats, + struct rtnl_link_stats64 *core_stats) +{ + struct efx_ef10_nic_data *nic_data = efx->nic_data; + + /* In atomic context, cannot update HW stats. Just update the + * software stats and return so the caller can continue. + */ + efx_update_sw_stats(efx, nic_data->stats); + return efx_ef10_update_stats_common(efx, full_stats, core_stats); +} + static void efx_ef10_push_irq_moderation(struct efx_channel *channel) { struct efx_nic *efx = channel->efx; @@ -3998,6 +4001,7 @@ const struct efx_nic_type efx_hunt_a0_vf_nic_type = { .finish_flr = efx_port_dummy_op_void, .describe_stats = efx_ef10_describe_stats, .update_stats = efx_ef10_update_stats_vf, + .update_stats_atomic = efx_ef10_update_stats_atomic_vf, .start_stats = efx_port_dummy_op_void, .pull_stats = efx_port_dummy_op_void, .stop_stats = efx_port_dummy_op_void, diff --git a/drivers/net/ethernet/sfc/efx_common.c b/drivers/net/ethernet/sfc/efx_common.c index c256db241570..72a3f0e09f52 100644 --- a/drivers/net/ethernet/sfc/efx_common.c +++ b/drivers/net/ethernet/sfc/efx_common.c @@ -602,7 +602,7 @@ void efx_net_stats(struct net_device *net_dev, struct rtnl_link_stats64 *stats) struct efx_nic *efx = netdev_priv(net_dev); spin_lock_bh(&efx->stats_lock); - efx->type->update_stats(efx, NULL, stats); + efx_nic_update_stats_atomic(efx, NULL, stats); spin_unlock_bh(&efx->stats_lock); } diff --git a/drivers/net/ethernet/sfc/net_driver.h b/drivers/net/ethernet/sfc/net_driver.h index 47aa753e64bd..9f7dfdf708cf 100644 --- a/drivers/net/ethernet/sfc/net_driver.h +++ b/drivers/net/ethernet/sfc/net_driver.h @@ -1172,6 +1172,9 @@ struct efx_udp_tunnel { * @describe_stats: Describe statistics for ethtool * @update_stats: Update statistics not provided by event handling. * Either argument may be %NULL. + * @update_stats_atomic: Update statistics while in atomic context, if that + * is more limiting than @update_stats. Otherwise, leave %NULL and + * driver core will call @update_stats. * @start_stats: Start the regular fetching of statistics * @pull_stats: Pull stats from the NIC and wait until they arrive. * @stop_stats: Stop the regular fetching of statistics @@ -1316,6 +1319,8 @@ struct efx_nic_type { size_t (*describe_stats)(struct efx_nic *efx, u8 *names); size_t (*update_stats)(struct efx_nic *efx, u64 *full_stats, struct rtnl_link_stats64 *core_stats); + size_t (*update_stats_atomic)(struct efx_nic *efx, u64 *full_stats, + struct rtnl_link_stats64 *core_stats); void (*start_stats)(struct efx_nic *efx); void (*pull_stats)(struct efx_nic *efx); void (*stop_stats)(struct efx_nic *efx); diff --git a/drivers/net/ethernet/sfc/nic_common.h b/drivers/net/ethernet/sfc/nic_common.h index 82271f0b8627..b9cafe9cd568 100644 --- a/drivers/net/ethernet/sfc/nic_common.h +++ b/drivers/net/ethernet/sfc/nic_common.h @@ -244,6 +244,13 @@ void efx_nic_update_stats(const struct efx_hw_stat_desc *desc, size_t count, const unsigned long *mask, u64 *stats, const void *dma_buf, bool accumulate); void efx_nic_fix_nodesc_drop_stat(struct efx_nic *efx, u64 *stat); +static inline size_t efx_nic_update_stats_atomic(struct efx_nic *efx, u64 *full_stats, + struct rtnl_link_stats64 *core_stats) +{ + if (efx->type->update_stats_atomic) + return efx->type->update_stats_atomic(efx, full_stats, core_stats); + return efx->type->update_stats(efx, full_stats, core_stats); +} #define EFX_MAX_FLUSH_TIME 5000 -- 2.25.1