From: Joerg Roedel <[email protected]> The .probe_finalize() call-back of some IOMMU drivers calls into arm_iommu_attach_device(). This function will call back into the IOMMU core code, where it tries to take group->mutex again, resulting in a deadlock.
As there is no reason why .probe_finalize() needs to be called under that mutex, move it after the lock has been released to fix the deadlock. Cc: Yong Wu <[email protected]> Reported-by: Yong Wu <[email protected]> Fixes: deac0b3bed26 ("iommu: Split off default domain allocation from group assignment") Signed-off-by: Joerg Roedel <[email protected]> --- drivers/iommu/iommu.c | 28 ++++++++++++++++++---------- 1 file changed, 18 insertions(+), 10 deletions(-) diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 629d209b8e88..d5d9fcbc9714 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -1683,17 +1683,8 @@ static void probe_alloc_default_domain(struct bus_type *bus, static int iommu_group_do_dma_attach(struct device *dev, void *data) { struct iommu_domain *domain = data; - const struct iommu_ops *ops; - int ret; - - ret = __iommu_attach_device(domain, dev); - - ops = domain->ops; - - if (ret == 0 && ops->probe_finalize) - ops->probe_finalize(dev); - return ret; + return __iommu_attach_device(domain, dev); } static int __iommu_group_dma_attach(struct iommu_group *group) @@ -1702,6 +1693,21 @@ static int __iommu_group_dma_attach(struct iommu_group *group) iommu_group_do_dma_attach); } +static int iommu_group_do_probe_finalize(struct device *dev, void *data) +{ + struct iommu_domain *domain = data; + + if (domain->ops->probe_finalize) + domain->ops->probe_finalize(dev); + + return 0; +} + +static void __iommu_group_dma_finalize(struct iommu_group *group) +{ + __iommu_group_for_each_dev(group, group->default_domain, + iommu_group_do_probe_finalize); +} static int iommu_do_create_direct_mappings(struct device *dev, void *data) { struct iommu_group *group = data; @@ -1754,6 +1760,8 @@ int bus_iommu_probe(struct bus_type *bus) if (ret) break; + + __iommu_group_dma_finalize(group); } return ret; -- 2.25.1
