From 3b1ea43009f2aca9f8ff0dd6540f6701e0871baf Mon Sep 17 00:00:00 2001 From: Devesh Sharma Date: Thu, 24 Dec 2015 13:14:07 -0500 Subject: RDMA/ocrdma: Depend on async link events from CNA Recently Dough Ledford reported a deadlock happening between ocrdma-load sequence and NetworkManager service issuing "open" on be2net interface. The deadlock happens when any be2net hook (e.g. open/close) is called in parallel to insmod ocrdma.ko. A. be2net is sending administrative open/close event to ocrdma holding device_list_mutex. It does this from ndo_open/ndo_stop hooks of be2net. So sequence of locks is rtnl_lock---> device_list lock B. When new ocrdma roce device gets registered, infiniband stack now takes rtnl_lock in ib_register_device() in GID initialization routines. So sequence of locks in this path is device_list lock ---> rtnl_lock. This improper locking sequence causes deadlock. With this patch we stop using administrative open and close events injected by be2net driver. These events were used to dispatch PORT_ACTIVE and PORT_ERROR events to the IB-stack. This patch implements a logic to receive async-link-events generated from CNA whenever link-state-change is detected. Now on, these async-events will be used to dispatch PORT_ACTIVE and PORT_ERROR events to IB-stack. Depending on async-events from CNA removes the need to hold device-list-mutex and thus breaks the busy-wait scenario. Reported-by: Doug Ledford CC: Sathya Perla Signed-off-by: Padmanabh Ratnakar Signed-off-by: Selvin Xavier Signed-off-by: Devesh Sharma Signed-off-by: Doug Ledford --- drivers/infiniband/hw/ocrdma/ocrdma_main.c | 34 ++++++++++++++++++++++-------- 1 file changed, 25 insertions(+), 9 deletions(-) (limited to 'drivers/infiniband/hw/ocrdma/ocrdma_main.c') diff --git a/drivers/infiniband/hw/ocrdma/ocrdma_main.c b/drivers/infiniband/hw/ocrdma/ocrdma_main.c index d47df97449ae..573849354cb9 100644 --- a/drivers/infiniband/hw/ocrdma/ocrdma_main.c +++ b/drivers/infiniband/hw/ocrdma/ocrdma_main.c @@ -289,6 +289,7 @@ static void ocrdma_remove_sysfiles(struct ocrdma_dev *dev) static struct ocrdma_dev *ocrdma_add(struct be_dev_info *dev_info) { int status = 0, i; + u8 lstate = 0; struct ocrdma_dev *dev; dev = (struct ocrdma_dev *)ib_alloc_device(sizeof(struct ocrdma_dev)); @@ -318,6 +319,11 @@ static struct ocrdma_dev *ocrdma_add(struct be_dev_info *dev_info) if (status) goto alloc_err; + /* Query Link state and update */ + status = ocrdma_mbx_get_link_speed(dev, NULL, &lstate); + if (!status) + ocrdma_update_link_state(dev, lstate); + for (i = 0; i < ARRAY_SIZE(ocrdma_attributes); i++) if (device_create_file(&dev->ibdev.dev, ocrdma_attributes[i])) goto sysfs_err; @@ -372,7 +378,7 @@ static void ocrdma_remove(struct ocrdma_dev *dev) ocrdma_remove_free(dev); } -static int ocrdma_open(struct ocrdma_dev *dev) +static int ocrdma_dispatch_port_active(struct ocrdma_dev *dev) { struct ib_event port_event; @@ -383,7 +389,7 @@ static int ocrdma_open(struct ocrdma_dev *dev) return 0; } -static int ocrdma_close(struct ocrdma_dev *dev) +static int ocrdma_dispatch_port_error(struct ocrdma_dev *dev) { struct ib_event err_event; @@ -396,7 +402,7 @@ static int ocrdma_close(struct ocrdma_dev *dev) static void ocrdma_shutdown(struct ocrdma_dev *dev) { - ocrdma_close(dev); + ocrdma_dispatch_port_error(dev); ocrdma_remove(dev); } @@ -407,18 +413,28 @@ static void ocrdma_shutdown(struct ocrdma_dev *dev) static void ocrdma_event_handler(struct ocrdma_dev *dev, u32 event) { switch (event) { - case BE_DEV_UP: - ocrdma_open(dev); - break; - case BE_DEV_DOWN: - ocrdma_close(dev); - break; case BE_DEV_SHUTDOWN: ocrdma_shutdown(dev); break; + default: + break; } } +void ocrdma_update_link_state(struct ocrdma_dev *dev, u8 lstate) +{ + if (!(dev->flags & OCRDMA_FLAGS_LINK_STATUS_INIT)) { + dev->flags |= OCRDMA_FLAGS_LINK_STATUS_INIT; + if (!lstate) + return; + } + + if (!lstate) + ocrdma_dispatch_port_error(dev); + else + ocrdma_dispatch_port_active(dev); +} + static struct ocrdma_driver ocrdma_drv = { .name = "ocrdma_driver", .add = ocrdma_add, -- cgit v1.2.3-59-g8ed1b