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Commit 9dc00f4c authored by Jesse Barnes's avatar Jesse Barnes Committed by Linus Torvalds
Browse files

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: default avatarJesse Barnes <jbarnes@virtuousgeek.org>
Tested-by: default avatarOded Gabbay <oded.gabbay@amd.com>
Cc: Joerg Roedel <jroedel@suse.de>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent e1d6d01a

drivers/iommu/amd_iommu_v2.c

+53 −31
Original line number Diff line number Diff line
@@ -513,24 +513,15 @@ static void finish_pri_tag(struct device_state *dev_state, 
	spin_unlock_irqrestore(&pasid_state->lock, flags);

}



static void do_fault(struct work_struct *work)

static void handle_fault_error(struct fault *fault)

{

	struct fault *fault = container_of(work, struct fault, work);

	int npages, write;

	struct page *page;



	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;



	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,
@@ -548,10 +539,41 @@ static void do_fault(struct work_struct *work) 
	default:

		BUG();

	}

	} else {

		set_pri_tag_status(fault->state, fault->tag, PPR_INVALID);

}



static void do_fault(struct work_struct *work)

{

	struct fault *fault = container_of(work, struct fault, work);

	struct mm_struct *mm;

	struct vm_area_struct *vma;

	u64 address;

	int ret, write;



	write = !!(fault->flags & PPR_FAULT_WRITE);



	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);