diff options
| author | Mohsin Bashir <mohsin.bashr@gmail.com> | 2025-08-25 13:02:03 -0700 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2025-08-27 18:56:19 -0700 |
| commit | bcf54e5d7cd0dccf6378e00f1f6ddff28b9f3989 (patch) | |
| tree | 3f9e0dbd298fb274fb409bfc8cfd8ead97c7707f | |
| parent | b1161b1863c5f3d592adba5accd6e5c79741720f (diff) | |
eth: fbnic: Reset MAC stats
Reset the MAC stats as part of the hardware stats reset to ensure
consistency. Currently, hardware stats are reset during device bring-up
and upon experiencing PCI errors; however, MAC stats are being skipped
during these resets.
When fbnic_reset_hw_stats() is called upon recovering from PCI error,
MAC stats are accessed outside the rtnl_lock. The only other access to
MAC stats is via the ethtool API, which is protected by rtnl_lock. This
can result in concurrent access to MAC stats and a potential race. Protect
the fbnic_reset_hw_stats() call in __fbnic_pm_attach() with rtnl_lock to
avoid this.
Note that fbnic_reset_hw_mac_stats() is called outside the hardware
stats lock which protects access to the fbnic_hw_stats. This is intentional
because MAC stats are fetched from the device outside this lock and are
exclusively read via the ethtool API.
Signed-off-by: Mohsin Bashir <mohsin.bashr@gmail.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Link: https://patch.msgid.link/20250825200206.2357713-4-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | drivers/net/ethernet/meta/fbnic/fbnic_hw_stats.c | 22 | ||||
| -rw-r--r-- | drivers/net/ethernet/meta/fbnic/fbnic_pci.c | 2 |
2 files changed, 24 insertions, 0 deletions
diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_hw_stats.c b/drivers/net/ethernet/meta/fbnic/fbnic_hw_stats.c index 77182922f018..8aa9a0e286bb 100644 --- a/drivers/net/ethernet/meta/fbnic/fbnic_hw_stats.c +++ b/drivers/net/ethernet/meta/fbnic/fbnic_hw_stats.c @@ -1,6 +1,8 @@ // SPDX-License-Identifier: GPL-2.0 /* Copyright (c) Meta Platforms, Inc. and affiliates. */ +#include <linux/rtnetlink.h> + #include "fbnic.h" static void fbnic_hw_stat_rst32(struct fbnic_dev *fbd, u32 reg, @@ -510,6 +512,16 @@ static void fbnic_get_pcie_stats_asic64(struct fbnic_dev *fbd, &pcie->ob_rd_no_np_cred); } +static void fbnic_reset_hw_mac_stats(struct fbnic_dev *fbd, + struct fbnic_mac_stats *mac_stats) +{ + const struct fbnic_mac *mac = fbd->mac; + + mac->get_eth_mac_stats(fbd, true, &mac_stats->eth_mac); + mac->get_eth_ctrl_stats(fbd, true, &mac_stats->eth_ctrl); + mac->get_rmon_stats(fbd, true, &mac_stats->rmon); +} + void fbnic_reset_hw_stats(struct fbnic_dev *fbd) { spin_lock(&fbd->hw_stats.lock); @@ -520,6 +532,16 @@ void fbnic_reset_hw_stats(struct fbnic_dev *fbd) fbnic_reset_hw_rxq_stats(fbd, fbd->hw_stats.hw_q); fbnic_reset_pcie_stats_asic(fbd, &fbd->hw_stats.pcie); spin_unlock(&fbd->hw_stats.lock); + + /* Once registered, the only other access to MAC stats is via the + * ethtool API which is protected by the rtnl_lock. The call to + * fbnic_reset_hw_stats() during PCI recovery is also protected + * by the rtnl_lock hence, we don't need the spinlock to access + * the MAC stats. + */ + if (fbd->netdev) + ASSERT_RTNL(); + fbnic_reset_hw_mac_stats(fbd, &fbd->hw_stats.mac); } void fbnic_init_hw_stats(struct fbnic_dev *fbd) diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_pci.c b/drivers/net/ethernet/meta/fbnic/fbnic_pci.c index 953297f667a2..ef7928b18ac0 100644 --- a/drivers/net/ethernet/meta/fbnic/fbnic_pci.c +++ b/drivers/net/ethernet/meta/fbnic/fbnic_pci.c @@ -491,7 +491,9 @@ static void __fbnic_pm_attach(struct device *dev) struct net_device *netdev = fbd->netdev; struct fbnic_net *fbn; + rtnl_lock(); fbnic_reset_hw_stats(fbd); + rtnl_unlock(); if (fbnic_init_failure(fbd)) return; |