diff options
| -rw-r--r-- | drivers/iommu/iommu.c | 28 |
1 files changed, 22 insertions, 6 deletions
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 65a3b3d886dc..959d895fc1df 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -283,13 +283,23 @@ static int __iommu_probe_device(struct device *dev, struct list_head *group_list const struct iommu_ops *ops = dev->bus->iommu_ops; struct iommu_device *iommu_dev; struct iommu_group *group; + static DEFINE_MUTEX(iommu_probe_device_lock); int ret; if (!ops) return -ENODEV; - - if (!dev_iommu_get(dev)) - return -ENOMEM; + /* + * Serialise to avoid races between IOMMU drivers registering in + * parallel and/or the "replay" calls from ACPI/OF code via client + * driver probe. Once the latter have been cleaned up we should + * probably be able to use device_lock() here to minimise the scope, + * but for now enforcing a simple global ordering is fine. + */ + mutex_lock(&iommu_probe_device_lock); + if (!dev_iommu_get(dev)) { + ret = -ENOMEM; + goto err_unlock; + } if (!try_module_get(ops->owner)) { ret = -EINVAL; @@ -309,11 +319,14 @@ static int __iommu_probe_device(struct device *dev, struct list_head *group_list ret = PTR_ERR(group); goto out_release; } - iommu_group_put(group); + mutex_lock(&group->mutex); if (group_list && !group->default_domain && list_empty(&group->entry)) list_add_tail(&group->entry, group_list); + mutex_unlock(&group->mutex); + iommu_group_put(group); + mutex_unlock(&iommu_probe_device_lock); iommu_device_link(iommu_dev, dev); return 0; @@ -328,6 +341,9 @@ out_module_put: err_free: dev_iommu_free(dev); +err_unlock: + mutex_unlock(&iommu_probe_device_lock); + return ret; } @@ -1799,11 +1815,11 @@ int bus_iommu_probe(struct bus_type *bus) return ret; list_for_each_entry_safe(group, next, &group_list, entry) { + mutex_lock(&group->mutex); + /* Remove item from the list */ list_del_init(&group->entry); - mutex_lock(&group->mutex); - /* Try to allocate default domain */ probe_alloc_default_domain(bus, group); |