From 6a146f3a5894b751cef16feb3d7903e45e3c445c Mon Sep 17 00:00:00 2001 From: "Guilherme G. Piccoli" Date: Mon, 10 Jul 2017 10:55:46 -0300 Subject: [PATCH] cxgb4: fix BUG() on interrupt deallocating path of ULD Since the introduction of ULD (Upper-Layer Drivers), the MSI-X deallocating path changed in cxgb4: the driver frees the interrupts of ULD when unregistering it or on shutdown PCI handler. Problem is that if a MSI-X is not freed before deallocated in the PCI layer, it will trigger a BUG() due to still "alive" interrupt being tentatively quiesced. The below trace was observed when doing a simple unbind of Chelsio's adapter PCI function, like: "echo 001e:80:00.4 > /sys/bus/pci/drivers/cxgb4/unbind" Trace: kernel BUG at drivers/pci/msi.c:352! Oops: Exception in kernel mode, sig: 5 [#1] ... NIP [c0000000005a5e60] free_msi_irqs+0xa0/0x250 LR [c0000000005a5e50] free_msi_irqs+0x90/0x250 Call Trace: [c0000000005a5e50] free_msi_irqs+0x90/0x250 (unreliable) [c0000000005a72c4] pci_disable_msix+0x124/0x180 [d000000011e06708] disable_msi+0x88/0xb0 [cxgb4] [d000000011e06948] free_some_resources+0xa8/0x160 [cxgb4] [d000000011e06d60] remove_one+0x170/0x3c0 [cxgb4] [c00000000058a910] pci_device_remove+0x70/0x110 [c00000000064ef04] device_release_driver_internal+0x1f4/0x2c0 ... This patch fixes the issue by refactoring the shutdown path of ULD on cxgb4 driver, by properly freeing and disabling interrupts on PCI remove handler too. Fixes: 0fbc81b3ad51 ("Allocate resources dynamically for all cxgb4 ULD's") Reported-by: Harsha Thyagaraja Signed-off-by: Guilherme G. Piccoli Signed-off-by: David S. Miller --- .../net/ethernet/chelsio/cxgb4/cxgb4_main.c | 16 ++++--- .../net/ethernet/chelsio/cxgb4/cxgb4_uld.c | 42 +++++++++++-------- 2 files changed, 36 insertions(+), 22 deletions(-) diff --git a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c index 86f92e31e8aa..e403fa18f1b1 100644 --- a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c +++ b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c @@ -2083,12 +2083,12 @@ static void detach_ulds(struct adapter *adap) mutex_lock(&uld_mutex); list_del(&adap->list_node); + for (i = 0; i < CXGB4_ULD_MAX; i++) - if (adap->uld && adap->uld[i].handle) { + if (adap->uld && adap->uld[i].handle) adap->uld[i].state_change(adap->uld[i].handle, CXGB4_STATE_DETACH); - adap->uld[i].handle = NULL; - } + if (netevent_registered && list_empty(&adapter_list)) { unregister_netevent_notifier(&cxgb4_netevent_nb); netevent_registered = false; @@ -5303,8 +5303,10 @@ static void remove_one(struct pci_dev *pdev) */ destroy_workqueue(adapter->workq); - if (is_uld(adapter)) + if (is_uld(adapter)) { detach_ulds(adapter); + t4_uld_clean_up(adapter); + } disable_interrupts(adapter); @@ -5385,7 +5387,11 @@ static void shutdown_one(struct pci_dev *pdev) if (adapter->port[i]->reg_state == NETREG_REGISTERED) cxgb_close(adapter->port[i]); - t4_uld_clean_up(adapter); + if (is_uld(adapter)) { + detach_ulds(adapter); + t4_uld_clean_up(adapter); + } + disable_interrupts(adapter); disable_msi(adapter); diff --git a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_uld.c b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_uld.c index ec53fe9dec68..71a315bc1409 100644 --- a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_uld.c +++ b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_uld.c @@ -589,22 +589,37 @@ void t4_uld_mem_free(struct adapter *adap) kfree(adap->uld); } +/* This function should be called with uld_mutex taken. */ +static void cxgb4_shutdown_uld_adapter(struct adapter *adap, enum cxgb4_uld type) +{ + if (adap->uld[type].handle) { + adap->uld[type].handle = NULL; + adap->uld[type].add = NULL; + release_sge_txq_uld(adap, type); + + if (adap->flags & FULL_INIT_DONE) + quiesce_rx_uld(adap, type); + + if (adap->flags & USING_MSIX) + free_msix_queue_irqs_uld(adap, type); + + free_sge_queues_uld(adap, type); + free_queues_uld(adap, type); + } +} + void t4_uld_clean_up(struct adapter *adap) { unsigned int i; - if (!adap->uld) - return; + mutex_lock(&uld_mutex); for (i = 0; i < CXGB4_ULD_MAX; i++) { if (!adap->uld[i].handle) continue; - if (adap->flags & FULL_INIT_DONE) - quiesce_rx_uld(adap, i); - if (adap->flags & USING_MSIX) - free_msix_queue_irqs_uld(adap, i); - free_sge_queues_uld(adap, i); - free_queues_uld(adap, i); + + cxgb4_shutdown_uld_adapter(adap, i); } + mutex_unlock(&uld_mutex); } static void uld_init(struct adapter *adap, struct cxgb4_lld_info *lld) @@ -783,15 +798,8 @@ int cxgb4_unregister_uld(enum cxgb4_uld type) continue; if (type == CXGB4_ULD_ISCSIT && is_t4(adap->params.chip)) continue; - adap->uld[type].handle = NULL; - adap->uld[type].add = NULL; - release_sge_txq_uld(adap, type); - if (adap->flags & FULL_INIT_DONE) - quiesce_rx_uld(adap, type); - if (adap->flags & USING_MSIX) - free_msix_queue_irqs_uld(adap, type); - free_sge_queues_uld(adap, type); - free_queues_uld(adap, type); + + cxgb4_shutdown_uld_adapter(adap, type); } mutex_unlock(&uld_mutex);