drm/radeon: add proper support for RADEON_VM_BLOCK_SIZE v2

This patch makes it possible to decide how many address
bits are spend on the page directory vs the page tables.

v2: remove unintended change

Signed-off-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
diff --git a/drivers/gpu/drm/radeon/radeon_vm.c b/drivers/gpu/drm/radeon/radeon_vm.c
index f8d5b65..a128a4f 100644
--- a/drivers/gpu/drm/radeon/radeon_vm.c
+++ b/drivers/gpu/drm/radeon/radeon_vm.c
@@ -964,6 +964,8 @@
  */
 int radeon_vm_init(struct radeon_device *rdev, struct radeon_vm *vm)
 {
+	const unsigned align = min(RADEON_VM_PTB_ALIGN_SIZE,
+		RADEON_VM_PTE_COUNT * 8);
 	unsigned pd_size, pd_entries, pts_size;
 	int r;
 
@@ -985,7 +987,7 @@
 		return -ENOMEM;
 	}
 
-	r = radeon_bo_create(rdev, pd_size, RADEON_VM_PTB_ALIGN_SIZE, false,
+	r = radeon_bo_create(rdev, pd_size, align, false,
 			     RADEON_GEM_DOMAIN_VRAM, NULL,
 			     &vm->page_directory);
 	if (r)