diff options
| -rw-r--r-- | drivers/iommu/intel/iommu.c | 4 | ||||
| -rw-r--r-- | drivers/iommu/intel/svm.c | 6 | ||||
| -rw-r--r-- | drivers/iommu/ioasid.c | 38 | ||||
| -rw-r--r-- | include/linux/ioasid.h | 10 |
4 files changed, 47 insertions, 11 deletions
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c index 1b1ca63e6bbe..8b26223979a2 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -5198,7 +5198,7 @@ static void auxiliary_unlink_device(struct dmar_domain *domain, domain->auxd_refcnt--; if (!domain->auxd_refcnt && domain->default_pasid > 0) - ioasid_free(domain->default_pasid); + ioasid_put(domain->default_pasid); } static int aux_domain_add_dev(struct dmar_domain *domain, @@ -5259,7 +5259,7 @@ attach_failed: spin_unlock(&iommu->lock); spin_unlock_irqrestore(&device_domain_lock, flags); if (!domain->auxd_refcnt && domain->default_pasid > 0) - ioasid_free(domain->default_pasid); + ioasid_put(domain->default_pasid); return ret; } diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c index 3242ebd0bca3..4fa248b98031 100644 --- a/drivers/iommu/intel/svm.c +++ b/drivers/iommu/intel/svm.c @@ -598,7 +598,7 @@ intel_svm_bind_mm(struct device *dev, unsigned int flags, if (mm) { ret = mmu_notifier_register(&svm->notifier, mm); if (ret) { - ioasid_free(svm->pasid); + ioasid_put(svm->pasid); kfree(svm); kfree(sdev); goto out; @@ -616,7 +616,7 @@ intel_svm_bind_mm(struct device *dev, unsigned int flags, if (ret) { if (mm) mmu_notifier_unregister(&svm->notifier, mm); - ioasid_free(svm->pasid); + ioasid_put(svm->pasid); kfree(svm); kfree(sdev); goto out; @@ -689,7 +689,7 @@ static int intel_svm_unbind_mm(struct device *dev, u32 pasid) kfree_rcu(sdev, rcu); if (list_empty(&svm->devs)) { - ioasid_free(svm->pasid); + ioasid_put(svm->pasid); if (svm->mm) { mmu_notifier_unregister(&svm->notifier, svm->mm); /* Clear mm's pasid. */ diff --git a/drivers/iommu/ioasid.c b/drivers/iommu/ioasid.c index 0f8dd377aada..50ee27bbd04e 100644 --- a/drivers/iommu/ioasid.c +++ b/drivers/iommu/ioasid.c @@ -2,7 +2,7 @@ /* * I/O Address Space ID allocator. There is one global IOASID space, split into * subsets. Users create a subset with DECLARE_IOASID_SET, then allocate and - * free IOASIDs with ioasid_alloc and ioasid_free. + * free IOASIDs with ioasid_alloc and ioasid_put. */ #include <linux/ioasid.h> #include <linux/module.h> @@ -15,6 +15,7 @@ struct ioasid_data { struct ioasid_set *set; void *private; struct rcu_head rcu; + refcount_t refs; }; /* @@ -314,6 +315,7 @@ ioasid_t ioasid_alloc(struct ioasid_set *set, ioasid_t min, ioasid_t max, data->set = set; data->private = private; + refcount_set(&data->refs, 1); /* * Custom allocator needs allocator data to perform platform specific @@ -346,11 +348,34 @@ exit_free: EXPORT_SYMBOL_GPL(ioasid_alloc); /** - * ioasid_free - Free an IOASID + * ioasid_get - obtain a reference to the IOASID + */ +void ioasid_get(ioasid_t ioasid) +{ + struct ioasid_data *ioasid_data; + + spin_lock(&ioasid_allocator_lock); + ioasid_data = xa_load(&active_allocator->xa, ioasid); + if (ioasid_data) + refcount_inc(&ioasid_data->refs); + else + WARN_ON(1); + spin_unlock(&ioasid_allocator_lock); +} +EXPORT_SYMBOL_GPL(ioasid_get); + +/** + * ioasid_put - Release a reference to an ioasid * @ioasid: the ID to remove + * + * Put a reference to the IOASID, free it when the number of references drops to + * zero. + * + * Return: %true if the IOASID was freed, %false otherwise. */ -void ioasid_free(ioasid_t ioasid) +bool ioasid_put(ioasid_t ioasid) { + bool free = false; struct ioasid_data *ioasid_data; spin_lock(&ioasid_allocator_lock); @@ -360,6 +385,10 @@ void ioasid_free(ioasid_t ioasid) goto exit_unlock; } + free = refcount_dec_and_test(&ioasid_data->refs); + if (!free) + goto exit_unlock; + active_allocator->ops->free(ioasid, active_allocator->ops->pdata); /* Custom allocator needs additional steps to free the xa element */ if (active_allocator->flags & IOASID_ALLOCATOR_CUSTOM) { @@ -369,8 +398,9 @@ void ioasid_free(ioasid_t ioasid) exit_unlock: spin_unlock(&ioasid_allocator_lock); + return free; } -EXPORT_SYMBOL_GPL(ioasid_free); +EXPORT_SYMBOL_GPL(ioasid_put); /** * ioasid_find - Find IOASID data diff --git a/include/linux/ioasid.h b/include/linux/ioasid.h index 6f000d7a0ddc..e9dacd4b9f6b 100644 --- a/include/linux/ioasid.h +++ b/include/linux/ioasid.h @@ -34,7 +34,8 @@ struct ioasid_allocator_ops { #if IS_ENABLED(CONFIG_IOASID) ioasid_t ioasid_alloc(struct ioasid_set *set, ioasid_t min, ioasid_t max, void *private); -void ioasid_free(ioasid_t ioasid); +void ioasid_get(ioasid_t ioasid); +bool ioasid_put(ioasid_t ioasid); void *ioasid_find(struct ioasid_set *set, ioasid_t ioasid, bool (*getter)(void *)); int ioasid_register_allocator(struct ioasid_allocator_ops *allocator); @@ -48,10 +49,15 @@ static inline ioasid_t ioasid_alloc(struct ioasid_set *set, ioasid_t min, return INVALID_IOASID; } -static inline void ioasid_free(ioasid_t ioasid) +static inline void ioasid_get(ioasid_t ioasid) { } +static inline bool ioasid_put(ioasid_t ioasid) +{ + return false; +} + static inline void *ioasid_find(struct ioasid_set *set, ioasid_t ioasid, bool (*getter)(void *)) { |