Messages in this thread Patch in this message | | | From | Tina Zhang <> | Subject | [RFC PATCH 5/6] iommu: Support mm PASID 1:1 with sva domain | Date | Fri, 7 Jul 2023 09:34:40 +0800 |
| |
Each mm bound to devices gets a PASID and a corresponding sva domain allocated in iommu_sva_bind_device(), which are referenced by iommu_mm field of the mm. And that PASID and sva domain get released in iommu_sva_ unbind_device() when no devices are binding to that mm. As a result, during the life cycle, sva domain has 1:1 with mm PASID.
Since the required info of PASID and sva domain are kept in struct iommu_mm_data of a mm, use mm->iommu_mm field instead of the old pasid field in mm struct.
Signed-off-by: Tina Zhang <tina.zhang@intel.com> --- drivers/iommu/iommu-sva.c | 54 +++++++++++++++++++++++++++------------ drivers/iommu/iommu.c | 1 + include/linux/iommu.h | 8 +++--- 3 files changed, 42 insertions(+), 21 deletions(-)
diff --git a/drivers/iommu/iommu-sva.c b/drivers/iommu/iommu-sva.c index 7a41b6510e385..342d8ba9ab479 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 || @@ -33,9 +34,18 @@ 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; + } + mm->iommu_mm = iommu_mm; + ret = ida_alloc_range(&iommu_global_pasid_ida, min, max, GFP_KERNEL); - if (ret < min) + if (ret < min) { + kfree(iommu_mm); goto out; + } mm_set_pasid(mm, ret); ret = 0; out: @@ -61,7 +71,7 @@ static int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t ma */ struct iommu_sva *iommu_sva_bind_device(struct device *dev, struct mm_struct *mm) { - struct iommu_domain *domain; + struct iommu_domain *domain, *sva_domain = mm->iommu_mm->sva_domain; struct iommu_sva *handle; ioasid_t max_pasids; int ret; @@ -88,31 +98,41 @@ struct iommu_sva *iommu_sva_bind_device(struct device *dev, struct mm_struct *mm goto out_unlock; } - if (domain) { - domain->users++; - goto out; + if (unlikely(domain)) { + /* Re-attach the device to the same domain? */ + if (domain == sva_domain) { + goto out; + } else { + /* Didn't get detached from the previous domain? */ + ret = -EBUSY; + goto out_unlock; + } } - /* Allocate a new domain and set it on device pasid. */ - domain = iommu_sva_domain_alloc(dev, mm); - if (!domain) { - ret = -ENOMEM; - goto out_unlock; + if (sva_domain) { + sva_domain->users++; + } else { + /* Allocate a new domain and set it on device pasid. */ + sva_domain = iommu_sva_domain_alloc(dev, mm); + if (!sva_domain) { + ret = -ENOMEM; + goto out_unlock; + } + sva_domain->users = 1; } - ret = iommu_attach_device_pasid(domain, dev, mm_get_pasid(mm)); + ret = iommu_attach_device_pasid(sva_domain, dev, mm_get_pasid(mm)); if (ret) goto out_free_domain; - domain->users = 1; out: mutex_unlock(&iommu_sva_lock); handle->dev = dev; - handle->domain = domain; + handle->domain = sva_domain; return handle; out_free_domain: - iommu_domain_free(domain); + iommu_domain_free(sva_domain); out_unlock: mutex_unlock(&iommu_sva_lock); kfree(handle); @@ -136,10 +156,9 @@ void iommu_sva_unbind_device(struct iommu_sva *handle) struct device *dev = handle->dev; mutex_lock(&iommu_sva_lock); - if (--domain->users == 0) { - iommu_detach_device_pasid(domain, dev, pasid); + iommu_detach_device_pasid(domain, dev, pasid); + if (--domain->users == 0) iommu_domain_free(domain); - } mutex_unlock(&iommu_sva_lock); kfree(handle); } @@ -217,4 +236,5 @@ 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/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 35fa1c1b12826..2f55a157b1f15 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -3393,5 +3393,6 @@ struct iommu_domain *iommu_sva_domain_alloc(struct device *dev, domain->iopf_handler = iommu_sva_handle_iopf; domain->fault_data = mm; + mm->iommu_mm->sva_domain = domain; return domain; } diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 20135912584ba..1511ded7bc910 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -1175,20 +1175,20 @@ 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; + mm->iommu_mm = &default_iommu_mm; } static inline bool mm_valid_pasid(struct mm_struct *mm) { - return mm->pasid != IOMMU_PASID_INVALID; + return mm->iommu_mm->pasid != IOMMU_PASID_INVALID; } static inline u32 mm_get_pasid(struct mm_struct *mm) { - return mm->pasid; + return mm->iommu_mm->pasid; } static inline void mm_set_pasid(struct mm_struct *mm, u32 pasid) { - mm->pasid = pasid; + mm->iommu_mm->pasid = pasid; } void mm_pasid_drop(struct mm_struct *mm); struct iommu_sva *iommu_sva_bind_device(struct device *dev, -- 2.34.1
| |