drm/radeon: fence virtual address and free it once idle v4

Virtual address need to be fenced to know when we can safely remove it.
This patch also properly clear the pagetable. Previously it was
serouisly broken.

Kernel 3.5/3.4 need a similar patch but adapted for difference in mutex locking.

v2: For to update pagetable when unbinding bo (don't bailout if
    bo_va->valid is true).
v3: Add kernel 3.5/3.4 comment.
v4: Fix compilation warnings.

Signed-off-by: Jerome Glisse <jglisse@redhat.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
diff --git a/drivers/gpu/drm/radeon/radeon_cs.c b/drivers/gpu/drm/radeon/radeon_cs.c
index 8a4c49e..b4a0db24 100644
--- a/drivers/gpu/drm/radeon/radeon_cs.c
+++ b/drivers/gpu/drm/radeon/radeon_cs.c
@@ -278,6 +278,30 @@
 	return 0;
 }
 
+static void radeon_bo_vm_fence_va(struct radeon_cs_parser *parser,
+				  struct radeon_fence *fence)
+{
+	struct radeon_fpriv *fpriv = parser->filp->driver_priv;
+	struct radeon_vm *vm = &fpriv->vm;
+	struct radeon_bo_list *lobj;
+
+	if (parser->chunk_ib_idx == -1) {
+		return;
+	}
+	if ((parser->cs_flags & RADEON_CS_USE_VM) == 0) {
+		return;
+	}
+
+	list_for_each_entry(lobj, &parser->validated, tv.head) {
+		struct radeon_bo_va *bo_va;
+		struct radeon_bo *rbo = lobj->bo;
+
+		bo_va = radeon_bo_va(rbo, vm);
+		radeon_fence_unref(&bo_va->fence);
+		bo_va->fence = radeon_fence_ref(fence);
+	}
+}
+
 /**
  * cs_parser_fini() - clean parser states
  * @parser:	parser structure holding parsing context.
@@ -290,11 +314,14 @@
 {
 	unsigned i;
 
-	if (!error)
+	if (!error) {
+		/* fence all bo va before ttm_eu_fence_buffer_objects so bo are still reserved */
+		radeon_bo_vm_fence_va(parser, parser->ib.fence);
 		ttm_eu_fence_buffer_objects(&parser->validated,
 					    parser->ib.fence);
-	else
+	} else {
 		ttm_eu_backoff_reservation(&parser->validated);
+	}
 
 	if (parser->relocs != NULL) {
 		for (i = 0; i < parser->nrelocs; i++) {
@@ -388,7 +415,6 @@
 
 	if (parser->chunk_ib_idx == -1)
 		return 0;
-
 	if ((parser->cs_flags & RADEON_CS_USE_VM) == 0)
 		return 0;