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

[Jan Kara]

From: Jan Kara <j...@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