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However, there is no requirement to access the iommu device list in interrupt context. Therefore, a mutex is sufficient. This also prepares for the next change, which will iterate the iommu device list and call the probe callback within the locking area. Signed-off-by: Lu Baolu Reviewed-by: Kevin Tian Reviewed-by: Jason Gunthorpe --- drivers/iommu/iommu.c | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-) diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 68e648b55767..0af0b5544072 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -146,7 +146,7 @@ struct iommu_group_attribute iommu_group_attr_##_name = \ container_of(_kobj, struct iommu_group, kobj) static LIST_HEAD(iommu_device_list); -static DEFINE_SPINLOCK(iommu_device_lock); +static DEFINE_MUTEX(iommu_device_lock); static const struct bus_type * const iommu_buses[] = { &platform_bus_type, @@ -262,9 +262,9 @@ int iommu_device_register(struct iommu_device *iommu, if (hwdev) iommu->fwnode = dev_fwnode(hwdev); - spin_lock(&iommu_device_lock); + mutex_lock(&iommu_device_lock); list_add_tail(&iommu->list, &iommu_device_list); - spin_unlock(&iommu_device_lock); + mutex_unlock(&iommu_device_lock); for (int i = 0; i < ARRAY_SIZE(iommu_buses) && !err; i++) err = bus_iommu_probe(iommu_buses[i]); @@ -279,9 +279,9 @@ void iommu_device_unregister(struct iommu_device *iommu) for (int i = 0; i < ARRAY_SIZE(iommu_buses); i++) bus_for_each_dev(iommu_buses[i], NULL, iommu, remove_iommu_group); - spin_lock(&iommu_device_lock); + mutex_lock(&iommu_device_lock); list_del(&iommu->list); - spin_unlock(&iommu_device_lock); + mutex_unlock(&iommu_device_lock); /* Pairs with the alloc in generic_single_device_group() */ iommu_group_put(iommu->singleton_group); @@ -316,9 +316,9 @@ int iommu_device_register_bus(struct iommu_device *iommu, if (err) return err; - spin_lock(&iommu_device_lock); + mutex_lock(&iommu_device_lock); list_add_tail(&iommu->list, &iommu_device_list); - spin_unlock(&iommu_device_lock); + mutex_unlock(&iommu_device_lock); err = bus_iommu_probe(bus); if (err) { @@ -2033,9 +2033,9 @@ bool iommu_present(const struct bus_type *bus) for (int i = 0; i < ARRAY_SIZE(iommu_buses); i++) { if (iommu_buses[i] == bus) { - spin_lock(&iommu_device_lock); + mutex_lock(&iommu_device_lock); ret = !list_empty(&iommu_device_list); - spin_unlock(&iommu_device_lock); + mutex_unlock(&iommu_device_lock); } } return ret; @@ -2983,13 +2983,13 @@ const struct iommu_ops *iommu_ops_from_fwnode(struct fwnode_handle *fwnode) const struct iommu_ops *ops = NULL; struct iommu_device *iommu; - spin_lock(&iommu_device_lock); + mutex_lock(&iommu_device_lock); list_for_each_entry(iommu, &iommu_device_list, list) if (iommu->fwnode == fwnode) { ops = iommu->ops; break; } - spin_unlock(&iommu_device_lock); + mutex_unlock(&iommu_device_lock); return ops; }