This adds a helper to retrieve the iommu_domain which has been attached to
a {device, pasid}. One usage scenario of this helper exists in the I/O page
fault handling framework, where {device, pasid} was reported by hardware,
and software needs to retrieve the attached domain for further routing.Signed-off-by: Lu Baolu <[email protected]> --- include/linux/iommu.h | 8 ++++++++ drivers/iommu/iommu.c | 31 +++++++++++++++++++++++++++++++ 2 files changed, 39 insertions(+) diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 47c9aa5aa9c8..803e7b07605e 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -676,6 +676,8 @@ int iommu_attach_device_pasid(struct iommu_domain *domain, struct device *dev, ioasid_t pasid); void iommu_detach_device_pasid(struct iommu_domain *domain, struct device *dev, ioasid_t pasid); +struct iommu_domain * +iommu_get_domain_for_dev_pasid(struct device *dev, ioasid_t pasid); #else /* CONFIG_IOMMU_API */ @@ -1041,6 +1043,12 @@ static inline void iommu_detach_device_pasid(struct iommu_domain *domain, struct device *dev, ioasid_t pasid) { } + +static inline struct iommu_domain * +iommu_get_domain_for_dev_pasid(struct device *dev, ioasid_t pasid) +{ + return NULL; +} #endif /* CONFIG_IOMMU_API */ #ifdef CONFIG_IOMMU_SVA diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 4f90b71c6f6e..508fdcabda5c 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -40,6 +40,7 @@ struct iommu_group { struct kobject kobj; struct kobject *devices_kobj; struct list_head devices; + struct xarray pasid_array; struct mutex mutex; void *iommu_data; void (*iommu_data_release)(void *iommu_data); @@ -632,6 +633,7 @@ struct iommu_group *iommu_group_alloc(void) mutex_init(&group->mutex); INIT_LIST_HEAD(&group->devices); INIT_LIST_HEAD(&group->entry); + xa_init(&group->pasid_array); ret = ida_simple_get(&iommu_group_ida, 0, 0, GFP_KERNEL); if (ret < 0) { @@ -3086,6 +3088,7 @@ int iommu_attach_device_pasid(struct iommu_domain *domain, { struct iommu_group *group; int ret = -EINVAL; + void *curr; if (!domain->ops->attach_dev_pasid) return -EINVAL; @@ -3098,7 +3101,16 @@ int iommu_attach_device_pasid(struct iommu_domain *domain, if (iommu_group_device_count(group) != 1) goto out_unlock; + xa_lock(&group->pasid_array); + curr = __xa_cmpxchg(&group->pasid_array, pasid, NULL, + domain, GFP_KERNEL); + xa_unlock(&group->pasid_array); + if (curr) + goto out_unlock; + ret = domain->ops->attach_dev_pasid(domain, dev, pasid); + if (ret) + xa_erase(&group->pasid_array, pasid); out_unlock: mutex_unlock(&group->mutex); @@ -3118,6 +3130,25 @@ void iommu_detach_device_pasid(struct iommu_domain *domain, mutex_lock(&group->mutex); domain->ops->detach_dev_pasid(domain, dev, pasid); + xa_erase(&group->pasid_array, pasid); + mutex_unlock(&group->mutex); + iommu_group_put(group); +} + +struct iommu_domain * +iommu_get_domain_for_dev_pasid(struct device *dev, ioasid_t pasid) +{ + struct iommu_domain *domain; + struct iommu_group *group; + + group = iommu_group_get(dev); + if (!group) + return NULL; + + mutex_lock(&group->mutex); + domain = xa_load(&group->pasid_array, pasid); mutex_unlock(&group->mutex); iommu_group_put(group); + + return domain; } -- 2.25.1 _______________________________________________ iommu mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/iommu
