From: Lu Baolu baolu.lu@linux.intel.com
mainline inclusion from mainline-v6.11-rc1 commit 3e7f57d1ef3f5fbed58974fae38d35e430f57d35 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/IB4WDJ CVE: NA
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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The struct sva_iommu represents an association between an SVA domain and a PASID of a device. It's stored in the iommu group's pasid array and also tracked by a list in the per-mm data structure. Removes duplicate tracking of sva_iommu by eliminating the list.
Signed-off-by: Lu Baolu baolu.lu@linux.intel.com Reviewed-by: Jason Gunthorpe jgg@nvidia.com Reviewed-by: Kevin Tian kevin.tian@intel.com Link: https://lore.kernel.org/r/20240702063444.105814-3-baolu.lu@linux.intel.com Signed-off-by: Will Deacon will@kernel.org Signed-off-by: Kunkun Jiang jiangkunkun@huawei.com --- drivers/iommu/iommu-priv.h | 3 +++ drivers/iommu/iommu-sva.c | 30 ++++++++++++++++++++---------- drivers/iommu/iommu.c | 31 +++++++++++++++++++++++++++++++ include/linux/iommu.h | 2 -- 4 files changed, 54 insertions(+), 12 deletions(-)
diff --git a/drivers/iommu/iommu-priv.h b/drivers/iommu/iommu-priv.h index 2024a2313348..7708f60bd01a 100644 --- a/drivers/iommu/iommu-priv.h +++ b/drivers/iommu/iommu-priv.h @@ -27,4 +27,7 @@ void iommu_device_unregister_bus(struct iommu_device *iommu, struct bus_type *bus, struct notifier_block *nb);
+struct iommu_attach_handle *iommu_attach_handle_get(struct iommu_group *group, + ioasid_t pasid, + unsigned int type); #endif /* __LINUX_IOMMU_PRIV_H */ diff --git a/drivers/iommu/iommu-sva.c b/drivers/iommu/iommu-sva.c index 0fb923254062..9b7f62517419 100644 --- a/drivers/iommu/iommu-sva.c +++ b/drivers/iommu/iommu-sva.c @@ -41,7 +41,6 @@ static struct iommu_mm_data *iommu_alloc_mm_data(struct mm_struct *mm, struct de } iommu_mm->pasid = pasid; INIT_LIST_HEAD(&iommu_mm->sva_domains); - INIT_LIST_HEAD(&iommu_mm->sva_handles); /* * Make sure the write to mm->iommu_mm is not reordered in front of * initialization to iommu_mm fields. If it does, readers may see a @@ -69,11 +68,16 @@ static struct iommu_mm_data *iommu_alloc_mm_data(struct mm_struct *mm, struct de */ struct iommu_sva *iommu_sva_bind_device(struct device *dev, struct mm_struct *mm) { + struct iommu_group *group = dev->iommu_group; + struct iommu_attach_handle *attach_handle; struct iommu_mm_data *iommu_mm; struct iommu_domain *domain; struct iommu_sva *handle; int ret;
+ if (!group) + return ERR_PTR(-ENODEV); + mutex_lock(&iommu_sva_lock);
/* Allocate mm->pasid if necessary. */ @@ -83,12 +87,22 @@ struct iommu_sva *iommu_sva_bind_device(struct device *dev, struct mm_struct *mm goto out_unlock; }
- list_for_each_entry(handle, &mm->iommu_mm->sva_handles, handle_item) { - if (handle->dev == dev) { - refcount_inc(&handle->users); - mutex_unlock(&iommu_sva_lock); - return handle; + /* A bond already exists, just take a reference`. */ + attach_handle = iommu_attach_handle_get(group, iommu_mm->pasid, IOMMU_DOMAIN_SVA); + if (!IS_ERR(attach_handle)) { + handle = container_of(attach_handle, struct iommu_sva, handle); + if (attach_handle->domain->mm != mm) { + ret = -EBUSY; + goto out_unlock; } + refcount_inc(&handle->users); + mutex_unlock(&iommu_sva_lock); + return handle; + } + + if (PTR_ERR(attach_handle) != -ENOENT) { + ret = PTR_ERR(attach_handle); + goto out_unlock; }
handle = kzalloc(sizeof(*handle), GFP_KERNEL); @@ -99,7 +113,6 @@ struct iommu_sva *iommu_sva_bind_device(struct device *dev, struct mm_struct *mm
/* Search for an existing domain. */ list_for_each_entry(domain, &mm->iommu_mm->sva_domains, next) { - handle->handle.domain = domain; ret = iommu_attach_device_pasid(domain, dev, iommu_mm->pasid, &handle->handle); if (!ret) { @@ -115,7 +128,6 @@ struct iommu_sva *iommu_sva_bind_device(struct device *dev, struct mm_struct *mm goto out_free_handle; }
- handle->handle.domain = domain; ret = iommu_attach_device_pasid(domain, dev, iommu_mm->pasid, &handle->handle); if (ret) @@ -125,7 +137,6 @@ struct iommu_sva *iommu_sva_bind_device(struct device *dev, struct mm_struct *mm
out: refcount_set(&handle->users, 1); - list_add(&handle->handle_item, &mm->iommu_mm->sva_handles); mutex_unlock(&iommu_sva_lock); handle->dev = dev; return handle; @@ -159,7 +170,6 @@ void iommu_sva_unbind_device(struct iommu_sva *handle) mutex_unlock(&iommu_sva_lock); return; } - list_del(&handle->handle_item);
iommu_detach_device_pasid(domain, dev, iommu_mm->pasid); if (--domain->users == 0) { diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 463eba849495..2e05e2725e36 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -3698,3 +3698,34 @@ void iommu_free_global_pasid(ioasid_t pasid) ida_free(&iommu_global_pasid_ida, pasid); } EXPORT_SYMBOL_GPL(iommu_free_global_pasid); + +/** + * iommu_attach_handle_get - Return the attach handle + * @group: the iommu group that domain was attached to + * @pasid: the pasid within the group + * @type: matched domain type, 0 for any match + * + * Return handle or ERR_PTR(-ENOENT) on none, ERR_PTR(-EBUSY) on mismatch. + * + * Return the attach handle to the caller. The life cycle of an iommu attach + * handle is from the time when the domain is attached to the time when the + * domain is detached. Callers are required to synchronize the call of + * iommu_attach_handle_get() with domain attachment and detachment. The attach + * handle can only be used during its life cycle. + */ +struct iommu_attach_handle * +iommu_attach_handle_get(struct iommu_group *group, ioasid_t pasid, unsigned int type) +{ + struct iommu_attach_handle *handle; + + xa_lock(&group->pasid_array); + handle = xa_load(&group->pasid_array, pasid); + if (!handle) + handle = ERR_PTR(-ENOENT); + else if (type && handle->domain->type != type) + handle = ERR_PTR(-EBUSY); + xa_unlock(&group->pasid_array); + + return handle; +} +EXPORT_SYMBOL_NS_GPL(iommu_attach_handle_get, IOMMUFD_INTERNAL); diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 4634e70ad699..bc61593a4a9f 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -1123,14 +1123,12 @@ struct iommu_attach_handle { struct iommu_sva { struct iommu_attach_handle handle; struct device *dev; - struct list_head handle_item; refcount_t users; };
struct iommu_mm_data { u32 pasid; struct list_head sva_domains; - struct list_head sva_handles; };
int iommu_fwspec_init(struct device *dev, struct fwnode_handle *iommu_fwnode,