From: Jianfeng Tan Date: Tue, 24 Apr 2018 05:51:21 +0000 (+0000) Subject: bus/vdev: add lock on device list X-Git-Url: http://git.droids-corp.org/?a=commitdiff_plain;h=35f462839b69;p=dpdk.git bus/vdev: add lock on device list As we could add virtual devices from different threads now, we add a spin lock to protect the vdev device list. Suggested-by: Anatoly Burakov Signed-off-by: Jianfeng Tan Reviewed-by: Qi Zhang Acked-by: Anatoly Burakov --- diff --git a/drivers/bus/vdev/vdev.c b/drivers/bus/vdev/vdev.c index f8dd1f5e63..70964f54a3 100644 --- a/drivers/bus/vdev/vdev.c +++ b/drivers/bus/vdev/vdev.c @@ -33,6 +33,8 @@ TAILQ_HEAD(vdev_device_list, rte_vdev_device); static struct vdev_device_list vdev_device_list = TAILQ_HEAD_INITIALIZER(vdev_device_list); +static rte_spinlock_t vdev_device_list_lock = RTE_SPINLOCK_INITIALIZER; + struct vdev_driver_list vdev_driver_list = TAILQ_HEAD_INITIALIZER(vdev_driver_list); @@ -149,6 +151,7 @@ vdev_probe_all_drivers(struct rte_vdev_device *dev) return ret; } +/* The caller shall be responsible for thread-safe */ static struct rte_vdev_device * find_vdev(const char *name) { @@ -193,8 +196,8 @@ alloc_devargs(const char *name, const char *args) return devargs; } -int -rte_vdev_init(const char *name, const char *args) +static int +insert_vdev(const char *name, const char *args, struct rte_vdev_device **p_dev) { struct rte_vdev_device *dev; struct rte_devargs *devargs; @@ -203,10 +206,6 @@ rte_vdev_init(const char *name, const char *args) if (name == NULL) return -EINVAL; - dev = find_vdev(name); - if (dev) - return -EEXIST; - devargs = alloc_devargs(name, args); if (!devargs) return -ENOMEM; @@ -221,18 +220,18 @@ rte_vdev_init(const char *name, const char *args) dev->device.numa_node = SOCKET_ID_ANY; dev->device.name = devargs->name; - ret = vdev_probe_all_drivers(dev); - if (ret) { - if (ret > 0) - VDEV_LOG(ERR, "no driver found for %s\n", name); + if (find_vdev(name)) { + ret = -EEXIST; goto fail; } + TAILQ_INSERT_TAIL(&vdev_device_list, dev, next); TAILQ_INSERT_TAIL(&devargs_list, devargs, next); - TAILQ_INSERT_TAIL(&vdev_device_list, dev, next); - return 0; + if (p_dev) + *p_dev = dev; + return 0; fail: free(devargs->args); free(devargs); @@ -240,6 +239,33 @@ fail: return ret; } +int +rte_vdev_init(const char *name, const char *args) +{ + struct rte_vdev_device *dev; + struct rte_devargs *devargs; + int ret; + + rte_spinlock_lock(&vdev_device_list_lock); + ret = insert_vdev(name, args, &dev); + if (ret == 0) { + ret = vdev_probe_all_drivers(dev); + if (ret) { + if (ret > 0) + VDEV_LOG(ERR, "no driver found for %s\n", name); + /* If fails, remove it from vdev list */ + devargs = dev->device.devargs; + TAILQ_REMOVE(&vdev_device_list, dev, next); + TAILQ_REMOVE(&devargs_list, devargs, next); + free(devargs->args); + free(devargs); + free(dev); + } + } + rte_spinlock_unlock(&vdev_device_list_lock); + return ret; +} + static int vdev_remove_driver(struct rte_vdev_device *dev) { @@ -266,24 +292,28 @@ rte_vdev_uninit(const char *name) if (name == NULL) return -EINVAL; - dev = find_vdev(name); - if (!dev) - return -ENOENT; + rte_spinlock_lock(&vdev_device_list_lock); - devargs = dev->device.devargs; + dev = find_vdev(name); + if (!dev) { + ret = -ENOENT; + goto unlock; + } ret = vdev_remove_driver(dev); if (ret) - return ret; + goto unlock; TAILQ_REMOVE(&vdev_device_list, dev, next); - + devargs = dev->device.devargs; TAILQ_REMOVE(&devargs_list, devargs, next); - free(devargs->args); free(devargs); free(dev); - return 0; + +unlock: + rte_spinlock_unlock(&vdev_device_list_lock); + return ret; } static int @@ -314,19 +344,25 @@ vdev_scan(void) if (devargs->bus != &rte_vdev_bus) continue; - dev = find_vdev(devargs->name); - if (dev) - continue; - dev = calloc(1, sizeof(*dev)); if (!dev) return -1; + rte_spinlock_lock(&vdev_device_list_lock); + + if (find_vdev(devargs->name)) { + rte_spinlock_unlock(&vdev_device_list_lock); + free(dev); + continue; + } + dev->device.devargs = devargs; dev->device.numa_node = SOCKET_ID_ANY; dev->device.name = devargs->name; TAILQ_INSERT_TAIL(&vdev_device_list, dev, next); + + rte_spinlock_unlock(&vdev_device_list_lock); } return 0; @@ -340,6 +376,10 @@ vdev_probe(void) /* call the init function for each virtual device */ TAILQ_FOREACH(dev, &vdev_device_list, next) { + /* we don't use the vdev lock here, as it's only used in DPDK + * initialization; and we don't want to hold such a lock when + * we call each driver probe. + */ if (dev->device.driver) continue; @@ -360,15 +400,18 @@ vdev_find_device(const struct rte_device *start, rte_dev_cmp_t cmp, { struct rte_vdev_device *dev; + rte_spinlock_lock(&vdev_device_list_lock); TAILQ_FOREACH(dev, &vdev_device_list, next) { if (start && &dev->device == start) { start = NULL; continue; } if (cmp(&dev->device, data) == 0) - return &dev->device; + break; } - return NULL; + rte_spinlock_unlock(&vdev_device_list_lock); + + return dev ? &dev->device : NULL; } static int