[PATCH 6/7] drm/i915: Convert to use get_user_page_unlocked()

[Jan Kara]

From: Jan Kara <jack at suse.cz>

Convert __i915_gem_userptr_get_pages_worker() to use
get_user_page_unlocked() so that we don't unnecessarily leak knowledge of
mm locking into driver code.

CC: Daniel Vetter <daniel.vetter at intel.com>
CC: David Airlie <airlied at linux.ie>
CC: dri-devel at lists.freedesktop.org
Signed-off-by: Jan Kara <jack at suse.cz>
---
 drivers/gpu/drm/i915/i915_gem_userptr.c | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem_userptr.c b/drivers/gpu/drm/i915/i915_gem_userptr.c
index 8fd431bcdfd3..5138fe61d2fa 100644
--- a/drivers/gpu/drm/i915/i915_gem_userptr.c
+++ b/drivers/gpu/drm/i915/i915_gem_userptr.c
@@ -585,19 +585,18 @@ __i915_gem_userptr_get_pages_worker(struct work_struct *_work)
 	if (pvec != NULL) {
 		struct mm_struct *mm = obj->userptr.mm->mm;
 
-		down_read(&mm->mmap_sem);
 		while (pinned < num_pages) {
-			ret = get_user_pages(work->task, mm,
-					     obj->userptr.ptr + pinned * PAGE_SIZE,
-					     num_pages - pinned,
-					     !obj->userptr.read_only, 0,
-					     pvec + pinned, NULL);
+			ret = get_user_pages_unlocked(
+					work->task, mm,
+					obj->userptr.ptr + pinned * PAGE_SIZE,
+					num_pages - pinned,
+					!obj->userptr.read_only, 0,
+					pvec + pinned);
 			if (ret < 0)
 				break;
 
 			pinned += ret;
 		}
-		up_read(&mm->mmap_sem);
 	}
 
 	mutex_lock(&dev->struct_mutex);
-- 
2.1.4