From: Stefan Assmann <sassmann@xxxxxxxxx> [ Upstream commit 5ac49f3c2702f269d31cc37eb9308bc557953c4d ] As follow-up to the discussion with Jakub Kicinski about iavf locking being insufficient [1] convert iavf to use mutexes instead of bitops. The locking logic is kept as is, just a drop-in replacement of enum iavf_critical_section_t with separate mutexes. The only difference is that the mutexes will be destroyed before the module is unloaded. [1] https://lwn.net/ml/netdev/20210316150210.00007249%40intel.com/ Signed-off-by: Stefan Assmann <sassmann@xxxxxxxxx> Tested-by: Marek Szlosek <marek.szlosek@xxxxxxxxx> Signed-off-by: Tony Nguyen <anthony.l.nguyen@xxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/net/ethernet/intel/iavf/iavf.h | 9 +- .../net/ethernet/intel/iavf/iavf_ethtool.c | 10 +- drivers/net/ethernet/intel/iavf/iavf_main.c | 100 +++++++++--------- 3 files changed, 56 insertions(+), 63 deletions(-) diff --git a/drivers/net/ethernet/intel/iavf/iavf.h b/drivers/net/ethernet/intel/iavf/iavf.h index 90793b36126e..68c80f04113c 100644 --- a/drivers/net/ethernet/intel/iavf/iavf.h +++ b/drivers/net/ethernet/intel/iavf/iavf.h @@ -186,12 +186,6 @@ enum iavf_state_t { __IAVF_RUNNING, /* opened, working */ }; -enum iavf_critical_section_t { - __IAVF_IN_CRITICAL_TASK, /* cannot be interrupted */ - __IAVF_IN_CLIENT_TASK, - __IAVF_IN_REMOVE_TASK, /* device being removed */ -}; - #define IAVF_CLOUD_FIELD_OMAC 0x01 #define IAVF_CLOUD_FIELD_IMAC 0x02 #define IAVF_CLOUD_FIELD_IVLAN 0x04 @@ -236,6 +230,9 @@ struct iavf_adapter { struct iavf_q_vector *q_vectors; struct list_head vlan_filter_list; struct list_head mac_filter_list; + struct mutex crit_lock; + struct mutex client_lock; + struct mutex remove_lock; /* Lock to protect accesses to MAC and VLAN lists */ spinlock_t mac_vlan_list_lock; char misc_vector_name[IFNAMSIZ + 9]; diff --git a/drivers/net/ethernet/intel/iavf/iavf_ethtool.c b/drivers/net/ethernet/intel/iavf/iavf_ethtool.c index af43fbd8cb75..edbeb27213f8 100644 --- a/drivers/net/ethernet/intel/iavf/iavf_ethtool.c +++ b/drivers/net/ethernet/intel/iavf/iavf_ethtool.c @@ -1352,8 +1352,7 @@ static int iavf_add_fdir_ethtool(struct iavf_adapter *adapter, struct ethtool_rx if (!fltr) return -ENOMEM; - while (test_and_set_bit(__IAVF_IN_CRITICAL_TASK, - &adapter->crit_section)) { + while (!mutex_trylock(&adapter->crit_lock)) { if (--count == 0) { kfree(fltr); return -EINVAL; @@ -1378,7 +1377,7 @@ static int iavf_add_fdir_ethtool(struct iavf_adapter *adapter, struct ethtool_rx if (err && fltr) kfree(fltr); - clear_bit(__IAVF_IN_CRITICAL_TASK, &adapter->crit_section); + mutex_unlock(&adapter->crit_lock); return err; } @@ -1563,8 +1562,7 @@ iavf_set_adv_rss_hash_opt(struct iavf_adapter *adapter, return -EINVAL; } - while (test_and_set_bit(__IAVF_IN_CRITICAL_TASK, - &adapter->crit_section)) { + while (!mutex_trylock(&adapter->crit_lock)) { if (--count == 0) { kfree(rss_new); return -EINVAL; @@ -1600,7 +1598,7 @@ iavf_set_adv_rss_hash_opt(struct iavf_adapter *adapter, if (!err) mod_delayed_work(iavf_wq, &adapter->watchdog_task, 0); - clear_bit(__IAVF_IN_CRITICAL_TASK, &adapter->crit_section); + mutex_unlock(&adapter->crit_lock); if (!rss_new_add) kfree(rss_new); diff --git a/drivers/net/ethernet/intel/iavf/iavf_main.c b/drivers/net/ethernet/intel/iavf/iavf_main.c index e5e6a5b11e6d..23762a7ef740 100644 --- a/drivers/net/ethernet/intel/iavf/iavf_main.c +++ b/drivers/net/ethernet/intel/iavf/iavf_main.c @@ -132,21 +132,18 @@ enum iavf_status iavf_free_virt_mem_d(struct iavf_hw *hw, } /** - * iavf_lock_timeout - try to set bit but give up after timeout - * @adapter: board private structure - * @bit: bit to set + * iavf_lock_timeout - try to lock mutex but give up after timeout + * @lock: mutex that should be locked * @msecs: timeout in msecs * * Returns 0 on success, negative on failure **/ -static int iavf_lock_timeout(struct iavf_adapter *adapter, - enum iavf_critical_section_t bit, - unsigned int msecs) +static int iavf_lock_timeout(struct mutex *lock, unsigned int msecs) { unsigned int wait, delay = 10; for (wait = 0; wait < msecs; wait += delay) { - if (!test_and_set_bit(bit, &adapter->crit_section)) + if (mutex_trylock(lock)) return 0; msleep(delay); @@ -1940,7 +1937,7 @@ static void iavf_watchdog_task(struct work_struct *work) struct iavf_hw *hw = &adapter->hw; u32 reg_val; - if (test_and_set_bit(__IAVF_IN_CRITICAL_TASK, &adapter->crit_section)) + if (!mutex_trylock(&adapter->crit_lock)) goto restart_watchdog; if (adapter->flags & IAVF_FLAG_PF_COMMS_FAILED) @@ -1958,8 +1955,7 @@ static void iavf_watchdog_task(struct work_struct *work) adapter->state = __IAVF_STARTUP; adapter->flags &= ~IAVF_FLAG_PF_COMMS_FAILED; queue_delayed_work(iavf_wq, &adapter->init_task, 10); - clear_bit(__IAVF_IN_CRITICAL_TASK, - &adapter->crit_section); + mutex_unlock(&adapter->crit_lock); /* Don't reschedule the watchdog, since we've restarted * the init task. When init_task contacts the PF and * gets everything set up again, it'll restart the @@ -1969,14 +1965,13 @@ static void iavf_watchdog_task(struct work_struct *work) } adapter->aq_required = 0; adapter->current_op = VIRTCHNL_OP_UNKNOWN; - clear_bit(__IAVF_IN_CRITICAL_TASK, - &adapter->crit_section); + mutex_unlock(&adapter->crit_lock); queue_delayed_work(iavf_wq, &adapter->watchdog_task, msecs_to_jiffies(10)); goto watchdog_done; case __IAVF_RESETTING: - clear_bit(__IAVF_IN_CRITICAL_TASK, &adapter->crit_section); + mutex_unlock(&adapter->crit_lock); queue_delayed_work(iavf_wq, &adapter->watchdog_task, HZ * 2); return; case __IAVF_DOWN: @@ -1999,7 +1994,7 @@ static void iavf_watchdog_task(struct work_struct *work) } break; case __IAVF_REMOVE: - clear_bit(__IAVF_IN_CRITICAL_TASK, &adapter->crit_section); + mutex_unlock(&adapter->crit_lock); return; default: goto restart_watchdog; @@ -2021,7 +2016,7 @@ static void iavf_watchdog_task(struct work_struct *work) if (adapter->state == __IAVF_RUNNING || adapter->state == __IAVF_COMM_FAILED) iavf_detect_recover_hung(&adapter->vsi); - clear_bit(__IAVF_IN_CRITICAL_TASK, &adapter->crit_section); + mutex_unlock(&adapter->crit_lock); restart_watchdog: if (adapter->aq_required) queue_delayed_work(iavf_wq, &adapter->watchdog_task, @@ -2085,7 +2080,7 @@ static void iavf_disable_vf(struct iavf_adapter *adapter) memset(adapter->vf_res, 0, IAVF_VIRTCHNL_VF_RESOURCE_SIZE); iavf_shutdown_adminq(&adapter->hw); adapter->netdev->flags &= ~IFF_UP; - clear_bit(__IAVF_IN_CRITICAL_TASK, &adapter->crit_section); + mutex_unlock(&adapter->crit_lock); adapter->flags &= ~IAVF_FLAG_RESET_PENDING; adapter->state = __IAVF_DOWN; wake_up(&adapter->down_waitqueue); @@ -2118,15 +2113,14 @@ static void iavf_reset_task(struct work_struct *work) /* When device is being removed it doesn't make sense to run the reset * task, just return in such a case. */ - if (test_bit(__IAVF_IN_REMOVE_TASK, &adapter->crit_section)) + if (mutex_is_locked(&adapter->remove_lock)) return; - if (iavf_lock_timeout(adapter, __IAVF_IN_CRITICAL_TASK, 200)) { + if (iavf_lock_timeout(&adapter->crit_lock, 200)) { schedule_work(&adapter->reset_task); return; } - while (test_and_set_bit(__IAVF_IN_CLIENT_TASK, - &adapter->crit_section)) + while (!mutex_trylock(&adapter->client_lock)) usleep_range(500, 1000); if (CLIENT_ENABLED(adapter)) { adapter->flags &= ~(IAVF_FLAG_CLIENT_NEEDS_OPEN | @@ -2178,7 +2172,7 @@ static void iavf_reset_task(struct work_struct *work) dev_err(&adapter->pdev->dev, "Reset never finished (%x)\n", reg_val); iavf_disable_vf(adapter); - clear_bit(__IAVF_IN_CLIENT_TASK, &adapter->crit_section); + mutex_unlock(&adapter->client_lock); return; /* Do not attempt to reinit. It's dead, Jim. */ } @@ -2305,13 +2299,13 @@ static void iavf_reset_task(struct work_struct *work) adapter->state = __IAVF_DOWN; wake_up(&adapter->down_waitqueue); } - clear_bit(__IAVF_IN_CLIENT_TASK, &adapter->crit_section); - clear_bit(__IAVF_IN_CRITICAL_TASK, &adapter->crit_section); + mutex_unlock(&adapter->client_lock); + mutex_unlock(&adapter->crit_lock); return; reset_err: - clear_bit(__IAVF_IN_CLIENT_TASK, &adapter->crit_section); - clear_bit(__IAVF_IN_CRITICAL_TASK, &adapter->crit_section); + mutex_unlock(&adapter->client_lock); + mutex_unlock(&adapter->crit_lock); dev_err(&adapter->pdev->dev, "failed to allocate resources during reinit\n"); iavf_close(netdev); } @@ -2339,7 +2333,7 @@ static void iavf_adminq_task(struct work_struct *work) if (!event.msg_buf) goto out; - if (iavf_lock_timeout(adapter, __IAVF_IN_CRITICAL_TASK, 200)) + if (iavf_lock_timeout(&adapter->crit_lock, 200)) goto freedom; do { ret = iavf_clean_arq_element(hw, &event, &pending); @@ -2354,7 +2348,7 @@ static void iavf_adminq_task(struct work_struct *work) if (pending != 0) memset(event.msg_buf, 0, IAVF_MAX_AQ_BUF_SIZE); } while (pending); - clear_bit(__IAVF_IN_CRITICAL_TASK, &adapter->crit_section); + mutex_unlock(&adapter->crit_lock); if ((adapter->flags & (IAVF_FLAG_RESET_PENDING | IAVF_FLAG_RESET_NEEDED)) || @@ -2421,7 +2415,7 @@ static void iavf_client_task(struct work_struct *work) * later. */ - if (test_and_set_bit(__IAVF_IN_CLIENT_TASK, &adapter->crit_section)) + if (!mutex_trylock(&adapter->client_lock)) return; if (adapter->flags & IAVF_FLAG_SERVICE_CLIENT_REQUESTED) { @@ -2444,7 +2438,7 @@ static void iavf_client_task(struct work_struct *work) adapter->flags &= ~IAVF_FLAG_CLIENT_NEEDS_OPEN; } out: - clear_bit(__IAVF_IN_CLIENT_TASK, &adapter->crit_section); + mutex_unlock(&adapter->client_lock); } /** @@ -3047,8 +3041,7 @@ static int iavf_configure_clsflower(struct iavf_adapter *adapter, if (!filter) return -ENOMEM; - while (test_and_set_bit(__IAVF_IN_CRITICAL_TASK, - &adapter->crit_section)) { + while (!mutex_trylock(&adapter->crit_lock)) { if (--count == 0) goto err; udelay(1); @@ -3079,7 +3072,7 @@ static int iavf_configure_clsflower(struct iavf_adapter *adapter, if (err) kfree(filter); - clear_bit(__IAVF_IN_CRITICAL_TASK, &adapter->crit_section); + mutex_unlock(&adapter->crit_lock); return err; } @@ -3226,8 +3219,7 @@ static int iavf_open(struct net_device *netdev) return -EIO; } - while (test_and_set_bit(__IAVF_IN_CRITICAL_TASK, - &adapter->crit_section)) + while (!mutex_trylock(&adapter->crit_lock)) usleep_range(500, 1000); if (adapter->state != __IAVF_DOWN) { @@ -3262,7 +3254,7 @@ static int iavf_open(struct net_device *netdev) iavf_irq_enable(adapter, true); - clear_bit(__IAVF_IN_CRITICAL_TASK, &adapter->crit_section); + mutex_unlock(&adapter->crit_lock); return 0; @@ -3274,7 +3266,7 @@ static int iavf_open(struct net_device *netdev) err_setup_tx: iavf_free_all_tx_resources(adapter); err_unlock: - clear_bit(__IAVF_IN_CRITICAL_TASK, &adapter->crit_section); + mutex_unlock(&adapter->crit_lock); return err; } @@ -3298,8 +3290,7 @@ static int iavf_close(struct net_device *netdev) if (adapter->state <= __IAVF_DOWN_PENDING) return 0; - while (test_and_set_bit(__IAVF_IN_CRITICAL_TASK, - &adapter->crit_section)) + while (!mutex_trylock(&adapter->crit_lock)) usleep_range(500, 1000); set_bit(__IAVF_VSI_DOWN, adapter->vsi.state); @@ -3310,7 +3301,7 @@ static int iavf_close(struct net_device *netdev) adapter->state = __IAVF_DOWN_PENDING; iavf_free_traffic_irqs(adapter); - clear_bit(__IAVF_IN_CRITICAL_TASK, &adapter->crit_section); + mutex_unlock(&adapter->crit_lock); /* We explicitly don't free resources here because the hardware is * still active and can DMA into memory. Resources are cleared in @@ -3659,8 +3650,8 @@ static void iavf_init_task(struct work_struct *work) init_task.work); struct iavf_hw *hw = &adapter->hw; - if (iavf_lock_timeout(adapter, __IAVF_IN_CRITICAL_TASK, 5000)) { - dev_warn(&adapter->pdev->dev, "failed to set __IAVF_IN_CRITICAL_TASK in %s\n", __FUNCTION__); + if (iavf_lock_timeout(&adapter->crit_lock, 5000)) { + dev_warn(&adapter->pdev->dev, "failed to acquire crit_lock in %s\n", __FUNCTION__); return; } switch (adapter->state) { @@ -3695,7 +3686,7 @@ static void iavf_init_task(struct work_struct *work) } queue_delayed_work(iavf_wq, &adapter->init_task, HZ); out: - clear_bit(__IAVF_IN_CRITICAL_TASK, &adapter->crit_section); + mutex_unlock(&adapter->crit_lock); } /** @@ -3712,12 +3703,12 @@ static void iavf_shutdown(struct pci_dev *pdev) if (netif_running(netdev)) iavf_close(netdev); - if (iavf_lock_timeout(adapter, __IAVF_IN_CRITICAL_TASK, 5000)) - dev_warn(&adapter->pdev->dev, "failed to set __IAVF_IN_CRITICAL_TASK in %s\n", __FUNCTION__); + if (iavf_lock_timeout(&adapter->crit_lock, 5000)) + dev_warn(&adapter->pdev->dev, "failed to acquire crit_lock in %s\n", __FUNCTION__); /* Prevent the watchdog from running. */ adapter->state = __IAVF_REMOVE; adapter->aq_required = 0; - clear_bit(__IAVF_IN_CRITICAL_TASK, &adapter->crit_section); + mutex_unlock(&adapter->crit_lock); #ifdef CONFIG_PM pci_save_state(pdev); @@ -3811,6 +3802,9 @@ static int iavf_probe(struct pci_dev *pdev, const struct pci_device_id *ent) /* set up the locks for the AQ, do this only once in probe * and destroy them only once in remove */ + mutex_init(&adapter->crit_lock); + mutex_init(&adapter->client_lock); + mutex_init(&adapter->remove_lock); mutex_init(&hw->aq.asq_mutex); mutex_init(&hw->aq.arq_mutex); @@ -3862,8 +3856,7 @@ static int __maybe_unused iavf_suspend(struct device *dev_d) netif_device_detach(netdev); - while (test_and_set_bit(__IAVF_IN_CRITICAL_TASK, - &adapter->crit_section)) + while (!mutex_trylock(&adapter->crit_lock)) usleep_range(500, 1000); if (netif_running(netdev)) { @@ -3874,7 +3867,7 @@ static int __maybe_unused iavf_suspend(struct device *dev_d) iavf_free_misc_irq(adapter); iavf_reset_interrupt_capability(adapter); - clear_bit(__IAVF_IN_CRITICAL_TASK, &adapter->crit_section); + mutex_unlock(&adapter->crit_lock); return 0; } @@ -3936,7 +3929,7 @@ static void iavf_remove(struct pci_dev *pdev) struct iavf_hw *hw = &adapter->hw; int err; /* Indicate we are in remove and not to run reset_task */ - set_bit(__IAVF_IN_REMOVE_TASK, &adapter->crit_section); + mutex_lock(&adapter->remove_lock); cancel_delayed_work_sync(&adapter->init_task); cancel_work_sync(&adapter->reset_task); cancel_delayed_work_sync(&adapter->client_task); @@ -3958,8 +3951,8 @@ static void iavf_remove(struct pci_dev *pdev) iavf_request_reset(adapter); msleep(50); } - if (iavf_lock_timeout(adapter, __IAVF_IN_CRITICAL_TASK, 5000)) - dev_warn(&adapter->pdev->dev, "failed to set __IAVF_IN_CRITICAL_TASK in %s\n", __FUNCTION__); + if (iavf_lock_timeout(&adapter->crit_lock, 5000)) + dev_warn(&adapter->pdev->dev, "failed to acquire crit_lock in %s\n", __FUNCTION__); /* Shut down all the garbage mashers on the detention level */ adapter->state = __IAVF_REMOVE; @@ -3984,6 +3977,11 @@ static void iavf_remove(struct pci_dev *pdev) /* destroy the locks only once, here */ mutex_destroy(&hw->aq.arq_mutex); mutex_destroy(&hw->aq.asq_mutex); + mutex_destroy(&adapter->client_lock); + mutex_unlock(&adapter->crit_lock); + mutex_destroy(&adapter->crit_lock); + mutex_unlock(&adapter->remove_lock); + mutex_destroy(&adapter->remove_lock); iounmap(hw->hw_addr); pci_release_regions(pdev); -- 2.30.2
