[PATCH 59/64] drivers/iommu: use mm locking helpers

From: Davidlohr Bueso
Date: Sun Feb 04 2018 - 20:32:16 EST


From: Davidlohr Bueso <dave@xxxxxxxxxxxx>

This becomes quite straightforward with the mmrange in place.

Signed-off-by: Davidlohr Bueso <dbueso@xxxxxxx>
---
drivers/iommu/amd_iommu_v2.c | 4 ++--
drivers/iommu/intel-svm.c | 4 ++--
2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/iommu/amd_iommu_v2.c b/drivers/iommu/amd_iommu_v2.c
index 15a7103fd84c..d3aee158d251 100644
--- a/drivers/iommu/amd_iommu_v2.c
+++ b/drivers/iommu/amd_iommu_v2.c
@@ -523,7 +523,7 @@ static void do_fault(struct work_struct *work)
flags |= FAULT_FLAG_WRITE;
flags |= FAULT_FLAG_REMOTE;

- down_read(&mm->mmap_sem);
+ mm_read_lock(mm, &mmrange);
vma = find_extend_vma(mm, address, &mmrange);
if (!vma || address < vma->vm_start)
/* failed to get a vma in the right range */
@@ -535,7 +535,7 @@ static void do_fault(struct work_struct *work)

ret = handle_mm_fault(vma, address, flags, &mmrange);
out:
- up_read(&mm->mmap_sem);
+ mm_read_unlock(mm, &mmrange);

if (ret & VM_FAULT_ERROR)
/* failed to service fault */
diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c
index 6a74386ee83f..c4d0d2398052 100644
--- a/drivers/iommu/intel-svm.c
+++ b/drivers/iommu/intel-svm.c
@@ -643,7 +643,7 @@ static irqreturn_t prq_event_thread(int irq, void *d)
if (!is_canonical_address(address))
goto bad_req;

- down_read(&svm->mm->mmap_sem);
+ mm_read_lock(svm->mm, &mmrange);
vma = find_extend_vma(svm->mm, address, &mmrange);
if (!vma || address < vma->vm_start)
goto invalid;
@@ -658,7 +658,7 @@ static irqreturn_t prq_event_thread(int irq, void *d)

result = QI_RESP_SUCCESS;
invalid:
- up_read(&svm->mm->mmap_sem);
+ mm_read_unlock(svm->mm, &mmrange);
mmput(svm->mm);
bad_req:
/* Accounting for major/minor faults? */
--
2.13.6