diff options
| -rw-r--r-- | drivers/iommu/iommufd/driver.c | 28 | ||||
| -rw-r--r-- | include/linux/iommufd.h | 44 |
2 files changed, 72 insertions, 0 deletions
diff --git a/drivers/iommu/iommufd/driver.c b/drivers/iommu/iommufd/driver.c index 887719016804..e578ef32d30c 100644 --- a/drivers/iommu/iommufd/driver.c +++ b/drivers/iommu/iommufd/driver.c @@ -3,6 +3,34 @@ */ #include "iommufd_private.h" +/* Driver should use a per-structure helper in include/linux/iommufd.h */ +int _iommufd_object_depend(struct iommufd_object *obj_dependent, + struct iommufd_object *obj_depended) +{ + /* Reject self dependency that dead locks */ + if (obj_dependent == obj_depended) + return -EINVAL; + /* Only support dependency between two objects of the same type */ + if (obj_dependent->type != obj_depended->type) + return -EINVAL; + + refcount_inc(&obj_depended->users); + return 0; +} +EXPORT_SYMBOL_NS_GPL(_iommufd_object_depend, "IOMMUFD"); + +/* Driver should use a per-structure helper in include/linux/iommufd.h */ +void _iommufd_object_undepend(struct iommufd_object *obj_dependent, + struct iommufd_object *obj_depended) +{ + if (WARN_ON_ONCE(obj_dependent == obj_depended || + obj_dependent->type != obj_depended->type)) + return; + + refcount_dec(&obj_depended->users); +} +EXPORT_SYMBOL_NS_GPL(_iommufd_object_undepend, "IOMMUFD"); + /* Caller should xa_lock(&viommu->vdevs) to protect the return value */ struct device *iommufd_viommu_find_dev(struct iommufd_viommu *viommu, unsigned long vdev_id) diff --git a/include/linux/iommufd.h b/include/linux/iommufd.h index ce4011a2fc27..fa23439fa483 100644 --- a/include/linux/iommufd.h +++ b/include/linux/iommufd.h @@ -251,6 +251,10 @@ static inline int iommufd_vfio_compat_set_no_iommu(struct iommufd_ctx *ictx) #endif /* CONFIG_IOMMUFD */ #if IS_ENABLED(CONFIG_IOMMUFD_DRIVER_CORE) +int _iommufd_object_depend(struct iommufd_object *obj_dependent, + struct iommufd_object *obj_depended); +void _iommufd_object_undepend(struct iommufd_object *obj_dependent, + struct iommufd_object *obj_depended); struct device *iommufd_viommu_find_dev(struct iommufd_viommu *viommu, unsigned long vdev_id); int iommufd_viommu_get_vdev_id(struct iommufd_viommu *viommu, @@ -259,6 +263,18 @@ int iommufd_viommu_report_event(struct iommufd_viommu *viommu, enum iommu_veventq_type type, void *event_data, size_t data_len); #else /* !CONFIG_IOMMUFD_DRIVER_CORE */ +static inline int _iommufd_object_depend(struct iommufd_object *obj_dependent, + struct iommufd_object *obj_depended) +{ + return -EOPNOTSUPP; +} + +static inline void +_iommufd_object_undepend(struct iommufd_object *obj_dependent, + struct iommufd_object *obj_depended) +{ +} + static inline struct device * iommufd_viommu_find_dev(struct iommufd_viommu *viommu, unsigned long vdev_id) { @@ -298,4 +314,32 @@ static inline int iommufd_viommu_report_event(struct iommufd_viommu *viommu, BUILD_BUG_ON_ZERO(!__same_type(struct iommufd_hw_queue, \ ((drv_struct *)NULL)->member))) +/* + * Helpers for IOMMU driver to build/destroy a dependency between two sibling + * structures created by one of the allocators above + */ +#define iommufd_hw_queue_depend(dependent, depended, member) \ + ({ \ + int ret = -EINVAL; \ + \ + static_assert(__same_type(struct iommufd_hw_queue, \ + dependent->member)); \ + static_assert(__same_type(typeof(*dependent), *depended)); \ + if (!WARN_ON_ONCE(dependent->member.viommu != \ + depended->member.viommu)) \ + ret = _iommufd_object_depend(&dependent->member.obj, \ + &depended->member.obj); \ + ret; \ + }) + +#define iommufd_hw_queue_undepend(dependent, depended, member) \ + ({ \ + static_assert(__same_type(struct iommufd_hw_queue, \ + dependent->member)); \ + static_assert(__same_type(typeof(*dependent), *depended)); \ + WARN_ON_ONCE(dependent->member.viommu != \ + depended->member.viommu); \ + _iommufd_object_undepend(&dependent->member.obj, \ + &depended->member.obj); \ + }) #endif |