Messages in this thread Patch in this message | | | From | Tina Zhang <> | Subject | [PATCH 4/5] iommu: Support mm PASID 1:n with sva domains | Date | Tue, 8 Aug 2023 15:49:43 +0800 |
| |
Each mm bound to devices gets a PASID and corresponding sva domains allocated in iommu_sva_bind_device(), which are referenced by iommu_mm field of the mm. The PASID is released in __mmdrop(), while a sva domain is released when on one is using it (the reference count is decremented in iommu_sva_unbind_device()).
Since the required info of PASID and sva domains is kept in struct iommu_mm_data of a mm, use mm->iommu_mm field instead of the old pasid field in mm struct. The sva domain list is protected by iommu_sva_lock.
Besides, this patch removes mm_pasid_init(), as with the introduced iommu_mm structure, initializing mm pasid in mm_init() is unnecessary.
Signed-off-by: Tina Zhang <tina.zhang@intel.com> --- drivers/iommu/iommu-sva.c | 38 +++++++++++++++++++++++++------------- include/linux/iommu.h | 10 +++------- kernel/fork.c | 1 - 3 files changed, 28 insertions(+), 21 deletions(-)
diff --git a/drivers/iommu/iommu-sva.c b/drivers/iommu/iommu-sva.c index 0a4a1ed40814..35366f51ad27 100644 --- a/drivers/iommu/iommu-sva.c +++ b/drivers/iommu/iommu-sva.c @@ -15,6 +15,7 @@ static DEFINE_IDA(iommu_global_pasid_ida); /* Allocate a PASID for the mm within range (inclusive) */ static int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t max) { + struct iommu_mm_data *iommu_mm = NULL; int ret = 0; if (min == IOMMU_PASID_INVALID || @@ -33,11 +34,22 @@ static int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t ma goto out; } + iommu_mm = kzalloc(sizeof(struct iommu_mm_data), GFP_KERNEL); + if (!iommu_mm) { + ret = -ENOMEM; + goto out; + } + ret = ida_alloc_range(&iommu_global_pasid_ida, min, max, GFP_KERNEL); - if (ret < 0) + if (ret < 0) { + kfree(iommu_mm); goto out; + } + + iommu_mm->pasid = ret; + mm->iommu_mm = iommu_mm; + INIT_LIST_HEAD(&mm->iommu_mm->sva_domains); - mm->pasid = ret; ret = 0; out: mutex_unlock(&iommu_sva_lock); @@ -82,16 +94,12 @@ struct iommu_sva *iommu_sva_bind_device(struct device *dev, struct mm_struct *mm mutex_lock(&iommu_sva_lock); /* Search for an existing domain. */ - domain = iommu_get_domain_for_dev_pasid(dev, mm_get_pasid(mm), - IOMMU_DOMAIN_SVA); - if (IS_ERR(domain)) { - ret = PTR_ERR(domain); - goto out_unlock; - } - - if (domain) { - domain->users++; - goto out; + list_for_each_entry(domain, &mm->iommu_mm->sva_domains, next) { + ret = iommu_attach_device_pasid(domain, dev, mm_get_pasid(mm)); + if (!ret) { + domain->users++; + goto out; + } } /* Allocate a new domain and set it on device pasid. */ @@ -105,6 +113,8 @@ struct iommu_sva *iommu_sva_bind_device(struct device *dev, struct mm_struct *mm if (ret) goto out_free_domain; domain->users = 1; + list_add(&domain->next, &mm->iommu_mm->sva_domains); + out: mutex_unlock(&iommu_sva_lock); handle->dev = dev; @@ -137,8 +147,9 @@ void iommu_sva_unbind_device(struct iommu_sva *handle) struct device *dev = handle->dev; mutex_lock(&iommu_sva_lock); + iommu_detach_device_pasid(domain, dev, pasid); if (--domain->users == 0) { - iommu_detach_device_pasid(domain, dev, pasid); + list_del(&domain->next); iommu_domain_free(domain); } mutex_unlock(&iommu_sva_lock); @@ -218,4 +229,5 @@ void mm_pasid_drop(struct mm_struct *mm) return; ida_free(&iommu_global_pasid_ida, mm_get_pasid(mm)); + kfree(mm->iommu_mm); } diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 435d1c1afd23..6a87df6d8637 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -109,6 +109,7 @@ struct iommu_domain { struct { /* IOMMU_DOMAIN_SVA */ struct mm_struct *mm; int users; + struct list_head next; }; }; }; @@ -1177,17 +1178,13 @@ static inline bool tegra_dev_iommu_get_stream_id(struct device *dev, u32 *stream } #ifdef CONFIG_IOMMU_SVA -static inline void mm_pasid_init(struct mm_struct *mm) -{ - mm->pasid = IOMMU_PASID_INVALID; -} static inline bool mm_valid_pasid(struct mm_struct *mm) { - return mm->pasid != IOMMU_PASID_INVALID; + return mm->iommu_mm ? true : false; } static inline u32 mm_get_pasid(struct mm_struct *mm) { - return mm->pasid; + return mm->iommu_mm ? mm->iommu_mm->pasid : IOMMU_PASID_INVALID; } void mm_pasid_drop(struct mm_struct *mm); struct iommu_sva *iommu_sva_bind_device(struct device *dev, @@ -1209,7 +1206,6 @@ static inline u32 iommu_sva_get_pasid(struct iommu_sva *handle) { return IOMMU_PASID_INVALID; } -static inline void mm_pasid_init(struct mm_struct *mm) {} static inline bool mm_valid_pasid(struct mm_struct *mm) { return false; } static inline u32 mm_get_pasid(struct mm_struct *mm) { diff --git a/kernel/fork.c b/kernel/fork.c index d2e12b6d2b18..f06392dd1ca8 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1274,7 +1274,6 @@ static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p, mm_init_cpumask(mm); mm_init_aio(mm); mm_init_owner(mm, p); - mm_pasid_init(mm); RCU_INIT_POINTER(mm->exe_file, NULL); mmu_notifier_subscriptions_init(mm); init_tlb_flush_pending(mm); -- 2.17.1
| |