mm: replace get_user_pages() write/force parameters with gup_flags

This removes the 'write' and 'force' from get_user_pages() and replaces
them with 'gup_flags' to make the use of FOLL_FORCE explicit in callers
as use of this flag can result in surprising behaviour (and hence bugs)
within the mm subsystem.

Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
Acked-by: Christian König <christian.koenig@amd.com>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 9 insertions, 5 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index 887483b8b818..dcaf691f56b5 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -555,10 +555,13 @@ struct amdgpu_ttm_tt {
 int amdgpu_ttm_tt_get_user_pages(struct ttm_tt *ttm, struct page **pages)
 {
         struct amdgpu_ttm_tt *gtt = (void *)ttm;
-        int write = !(gtt->userflags & AMDGPU_GEM_USERPTR_READONLY);
+        unsigned int flags = 0;
         unsigned pinned = 0;
         int r;
 
+        if (!(gtt->userflags & AMDGPU_GEM_USERPTR_READONLY))
+                flags |= FOLL_WRITE;
+
         if (gtt->userflags & AMDGPU_GEM_USERPTR_ANONONLY) {
                 /* check that we only use anonymous memory
                    to prevent problems with writeback */
@@ -581,7 +584,7 @@ int amdgpu_ttm_tt_get_user_pages(struct ttm_tt *ttm, struct page **pages)
                 list_add(&guptask.list, &gtt->guptasks);
                 spin_unlock(&gtt->guptasklock);
 
-                r = get_user_pages(userptr, num_pages, write, 0, p, NULL);
+                r = get_user_pages(userptr, num_pages, flags, p, NULL);
 
                 spin_lock(&gtt->guptasklock);
                 list_del(&guptask.list);
diff --git a/drivers/gpu/drm/radeon/radeon_ttm.c b/drivers/gpu/drm/radeon/radeon_ttm.c
index 455268214b89..3de5e6e21662 100644
--- a/drivers/gpu/drm/radeon/radeon_ttm.c
+++ b/drivers/gpu/drm/radeon/radeon_ttm.c
@@ -566,7 +566,8 @@ static int radeon_ttm_tt_pin_userptr(struct ttm_tt *ttm)
                 uint64_t userptr = gtt->userptr + pinned * PAGE_SIZE;
                 struct page **pages = ttm->pages + pinned;
 
-                r = get_user_pages(userptr, num_pages, write, 0, pages, NULL);
+                r = get_user_pages(userptr, num_pages, write ? FOLL_WRITE : 0,
+                                   pages, NULL);
                 if (r < 0)
                         goto release_pages;
 
diff --git a/drivers/gpu/drm/via/via_dmablit.c b/drivers/gpu/drm/via/via_dmablit.c
index 7e2a12c4fed2..1a3ad769f8c8 100644
--- a/drivers/gpu/drm/via/via_dmablit.c
+++ b/drivers/gpu/drm/via/via_dmablit.c
@@ -241,8 +241,8 @@ via_lock_all_dma_pages(drm_via_sg_info_t *vsg,  drm_via_dmablit_t *xfer)
         down_read(&current->mm->mmap_sem);
         ret = get_user_pages((unsigned long)xfer->mem_addr,
                              vsg->num_pages,
-                             (vsg->direction == DMA_FROM_DEVICE),
-                             0, vsg->pages, NULL);
+                             (vsg->direction == DMA_FROM_DEVICE) ? FOLL_WRITE : 0,
+                             vsg->pages, NULL);
 
         up_read(&current->mm->mmap_sem);
         if (ret != vsg->num_pages) {