drm/radeon: sync all BOs involved in a CS v2

commit 86b27638 upstream.

Not just the userspace relocs, otherwise we won't wait
for a swapped out page tables to be swapped in again.

v2: rebased on Alex current drm-fixes-3.18
Signed-off-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
[ luis: backported to 3.16: used Christian's backport to 3.17 ]
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

drivers/gpu/drm/radeon/radeon_cs.c

@@ -226,14 +226,11 @@ static int radeon_cs_get_ring(struct radeon_cs_parser *p, u32 ring, s32 priority
 
 static void radeon_cs_sync_rings(struct radeon_cs_parser *p)
 {
-	int i;
-
-	for (i = 0; i < p->nrelocs; i++) {
-		if (!p->relocs[i].robj)
-			continue;
+	struct radeon_cs_reloc *reloc;
 
+	list_for_each_entry(reloc, &p->validated, tv.head) {
 		radeon_semaphore_sync_to(p->ib.semaphore,
-					 p->relocs[i].robj->tbo.sync_obj);
+					 reloc->robj->tbo.sync_obj);
 	}
 }