From 9dc00f4c4fdd1fab12a4da9a966e535b4284b0a4 Mon Sep 17 00:00:00 2001 From: Jesse Barnes Date: Fri, 12 Dec 2014 16:55:30 -0800 Subject: [PATCH] iommu/amd: use handle_mm_fault directly This could be useful for debug in the future if we want to track major/minor faults more closely, and also avoids the put_page trick we used with gup. In order to do this, we also track the task struct in the PASID state structure. This lets us update the appropriate task stats after the fault has been handled, and may aid with debug in the future as well. Signed-off-by: Jesse Barnes Tested-by: Oded Gabbay Cc: Joerg Roedel Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/iommu/amd_iommu_v2.c | 84 ++++++++++++++++++++++++++++---------------- 1 file changed, 53 insertions(+), 31 deletions(-) diff --git a/drivers/iommu/amd_iommu_v2.c b/drivers/iommu/amd_iommu_v2.c index 90d734b..9c0d6e2 100644 --- a/drivers/iommu/amd_iommu_v2.c +++ b/drivers/iommu/amd_iommu_v2.c @@ -513,45 +513,67 @@ static void finish_pri_tag(struct device_state *dev_state, spin_unlock_irqrestore(&pasid_state->lock, flags); } +static void handle_fault_error(struct fault *fault) +{ + int status; + + if (!fault->dev_state->inv_ppr_cb) { + set_pri_tag_status(fault->state, fault->tag, PPR_INVALID); + return; + } + + status = fault->dev_state->inv_ppr_cb(fault->dev_state->pdev, + fault->pasid, + fault->address, + fault->flags); + switch (status) { + case AMD_IOMMU_INV_PRI_RSP_SUCCESS: + set_pri_tag_status(fault->state, fault->tag, PPR_SUCCESS); + break; + case AMD_IOMMU_INV_PRI_RSP_INVALID: + set_pri_tag_status(fault->state, fault->tag, PPR_INVALID); + break; + case AMD_IOMMU_INV_PRI_RSP_FAIL: + set_pri_tag_status(fault->state, fault->tag, PPR_FAILURE); + break; + default: + BUG(); + } +} + static void do_fault(struct work_struct *work) { struct fault *fault = container_of(work, struct fault, work); - int npages, write; - struct page *page; + struct mm_struct *mm; + struct vm_area_struct *vma; + u64 address; + int ret, write; write = !!(fault->flags & PPR_FAULT_WRITE); - down_read(&fault->state->mm->mmap_sem); - npages = get_user_pages(NULL, fault->state->mm, - fault->address, 1, write, 0, &page, NULL); - up_read(&fault->state->mm->mmap_sem); - - if (npages == 1) { - put_page(page); - } else if (fault->dev_state->inv_ppr_cb) { - int status; - - status = fault->dev_state->inv_ppr_cb(fault->dev_state->pdev, - fault->pasid, - fault->address, - fault->flags); - switch (status) { - case AMD_IOMMU_INV_PRI_RSP_SUCCESS: - set_pri_tag_status(fault->state, fault->tag, PPR_SUCCESS); - break; - case AMD_IOMMU_INV_PRI_RSP_INVALID: - set_pri_tag_status(fault->state, fault->tag, PPR_INVALID); - break; - case AMD_IOMMU_INV_PRI_RSP_FAIL: - set_pri_tag_status(fault->state, fault->tag, PPR_FAILURE); - break; - default: - BUG(); - } - } else { - set_pri_tag_status(fault->state, fault->tag, PPR_INVALID); + mm = fault->state->mm; + address = fault->address; + + down_read(&mm->mmap_sem); + vma = find_extend_vma(mm, address); + if (!vma || address < vma->vm_start) { + /* failed to get a vma in the right range */ + up_read(&mm->mmap_sem); + handle_fault_error(fault); + goto out; + } + + ret = handle_mm_fault(mm, vma, address, write); + if (ret & VM_FAULT_ERROR) { + /* failed to service fault */ + up_read(&mm->mmap_sem); + handle_fault_error(fault); + goto out; } + up_read(&mm->mmap_sem); + +out: finish_pri_tag(fault->dev_state, fault->state, fault->tag); put_pasid_state(fault->state); -- 2.7.4