diff options
| -rw-r--r-- | drivers/iommu/dmar.c | 2 | ||||
| -rw-r--r-- | drivers/iommu/intel-svm.c | 37 | ||||
| -rw-r--r-- | drivers/iommu/intel_irq_remapping.c | 2 | ||||
| -rw-r--r-- | include/linux/intel-iommu.h | 3 |
4 files changed, 36 insertions, 8 deletions
diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c index 62a400c5ba06..fb092f3f11cb 100644 --- a/drivers/iommu/dmar.c +++ b/drivers/iommu/dmar.c @@ -1353,7 +1353,7 @@ void dmar_disable_qi(struct intel_iommu *iommu) raw_spin_lock_irqsave(&iommu->register_lock, flags); - sts = dmar_readq(iommu->reg + DMAR_GSTS_REG); + sts = readl(iommu->reg + DMAR_GSTS_REG); if (!(sts & DMA_GSTS_QIES)) goto end; diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c index 50464833d0b8..d9939fa9b588 100644 --- a/drivers/iommu/intel-svm.c +++ b/drivers/iommu/intel-svm.c @@ -249,12 +249,30 @@ static void intel_flush_pasid_dev(struct intel_svm *svm, struct intel_svm_dev *s static void intel_mm_release(struct mmu_notifier *mn, struct mm_struct *mm) { struct intel_svm *svm = container_of(mn, struct intel_svm, notifier); + struct intel_svm_dev *sdev; + /* This might end up being called from exit_mmap(), *before* the page + * tables are cleared. And __mmu_notifier_release() will delete us from + * the list of notifiers so that our invalidate_range() callback doesn't + * get called when the page tables are cleared. So we need to protect + * against hardware accessing those page tables. + * + * We do it by clearing the entry in the PASID table and then flushing + * the IOTLB and the PASID table caches. This might upset hardware; + * perhaps we'll want to point the PASID to a dummy PGD (like the zero + * page) so that we end up taking a fault that the hardware really + * *has* to handle gracefully without affecting other processes. + */ svm->iommu->pasid_table[svm->pasid].val = 0; + wmb(); + + rcu_read_lock(); + list_for_each_entry_rcu(sdev, &svm->devs, list) { + intel_flush_pasid_dev(svm, sdev, svm->pasid); + intel_flush_svm_range_dev(svm, sdev, 0, -1, 0, !svm->mm); + } + rcu_read_unlock(); - /* There's no need to do any flush because we can't get here if there - * are any devices left anyway. */ - WARN_ON(!list_empty(&svm->devs)); } static const struct mmu_notifier_ops intel_mmuops = { @@ -379,7 +397,6 @@ int intel_svm_bind_mm(struct device *dev, int *pasid, int flags, struct svm_dev_ goto out; } iommu->pasid_table[svm->pasid].val = (u64)__pa(mm->pgd) | 1; - mm = NULL; } else iommu->pasid_table[svm->pasid].val = (u64)__pa(init_mm.pgd) | 1 | (1ULL << 11); wmb(); @@ -442,11 +459,11 @@ int intel_svm_unbind_mm(struct device *dev, int pasid) kfree_rcu(sdev, rcu); if (list_empty(&svm->devs)) { - mmu_notifier_unregister(&svm->notifier, svm->mm); idr_remove(&svm->iommu->pasid_idr, svm->pasid); if (svm->mm) - mmput(svm->mm); + mmu_notifier_unregister(&svm->notifier, svm->mm); + /* We mandate that no page faults may be outstanding * for the PASID when intel_svm_unbind_mm() is called. * If that is not obeyed, subtle errors will happen. @@ -507,6 +524,10 @@ static irqreturn_t prq_event_thread(int irq, void *d) struct intel_svm *svm = NULL; int head, tail, handled = 0; + /* Clear PPR bit before reading head/tail registers, to + * ensure that we get a new interrupt if needed. */ + writel(DMA_PRS_PPR, iommu->reg + DMAR_PRS_REG); + tail = dmar_readq(iommu->reg + DMAR_PQT_REG) & PRQ_RING_MASK; head = dmar_readq(iommu->reg + DMAR_PQH_REG) & PRQ_RING_MASK; while (head != tail) { @@ -551,6 +572,9 @@ static irqreturn_t prq_event_thread(int irq, void *d) * any faults on kernel addresses. */ if (!svm->mm) goto bad_req; + /* If the mm is already defunct, don't handle faults. */ + if (!atomic_inc_not_zero(&svm->mm->mm_users)) + goto bad_req; down_read(&svm->mm->mmap_sem); vma = find_extend_vma(svm->mm, address); if (!vma || address < vma->vm_start) @@ -567,6 +591,7 @@ static irqreturn_t prq_event_thread(int irq, void *d) result = QI_RESP_SUCCESS; invalid: up_read(&svm->mm->mmap_sem); + mmput(svm->mm); bad_req: /* Accounting for major/minor faults? */ rcu_read_lock(); diff --git a/drivers/iommu/intel_irq_remapping.c b/drivers/iommu/intel_irq_remapping.c index c12ba4516df2..ac596928f6b4 100644 --- a/drivers/iommu/intel_irq_remapping.c +++ b/drivers/iommu/intel_irq_remapping.c @@ -629,7 +629,7 @@ static void iommu_disable_irq_remapping(struct intel_iommu *iommu) raw_spin_lock_irqsave(&iommu->register_lock, flags); - sts = dmar_readq(iommu->reg + DMAR_GSTS_REG); + sts = readl(iommu->reg + DMAR_GSTS_REG); if (!(sts & DMA_GSTS_IRES)) goto end; diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h index 821273ca4873..2d9b650047a5 100644 --- a/include/linux/intel-iommu.h +++ b/include/linux/intel-iommu.h @@ -235,6 +235,9 @@ static inline void dmar_writeq(void __iomem *addr, u64 val) /* low 64 bit */ #define dma_frcd_page_addr(d) (d & (((u64)-1) << PAGE_SHIFT)) +/* PRS_REG */ +#define DMA_PRS_PPR ((u32)1) + #define IOMMU_WAIT_OP(iommu, offset, op, cond, sts) \ do { \ cycles_t start_time = get_cycles(); \ |