/* number of entries in page table */
 #define RADEON_VM_PTE_COUNT (1 << RADEON_VM_BLOCK_SIZE)
 
+/* PTBs (Page Table Blocks) need to be aligned to 32K */
+#define RADEON_VM_PTB_ALIGN_SIZE   32768
+#define RADEON_VM_PTB_ALIGN_MASK (RADEON_VM_PTB_ALIGN_SIZE - 1)
+#define RADEON_VM_PTB_ALIGN(a) (((a) + RADEON_VM_PTB_ALIGN_MASK) & ~RADEON_VM_PTB_ALIGN_MASK)
+
 struct radeon_vm {
        struct list_head                list;
        struct list_head                va;
 
                size += rdev->vm_manager.max_pfn * 8;
                size *= 2;
                r = radeon_sa_bo_manager_init(rdev, &rdev->vm_manager.sa_manager,
-                                             RADEON_GPU_PAGE_ALIGN(size),
-                                             RADEON_GPU_PAGE_SIZE,
+                                             RADEON_VM_PTB_ALIGN(size),
+                                             RADEON_VM_PTB_ALIGN_SIZE,
                                              RADEON_GEM_DOMAIN_VRAM);
                if (r) {
                        dev_err(rdev->dev, "failed to allocate vm bo (%dKB)\n",
        }
 
 retry:
-       pd_size = RADEON_GPU_PAGE_ALIGN(radeon_vm_directory_size(rdev));
+       pd_size = RADEON_VM_PTB_ALIGN(radeon_vm_directory_size(rdev));
        r = radeon_sa_bo_new(rdev, &rdev->vm_manager.sa_manager,
                             &vm->page_directory, pd_size,
-                            RADEON_GPU_PAGE_SIZE, false);
+                            RADEON_VM_PTB_ALIGN_SIZE, false);
        if (r == -ENOMEM) {
                r = radeon_vm_evict(rdev, vm);
                if (r)
 retry:
                r = radeon_sa_bo_new(rdev, &rdev->vm_manager.sa_manager,
                                     &vm->page_tables[pt_idx],
-                                    RADEON_VM_PTE_COUNT * 8,
-                                    RADEON_GPU_PAGE_SIZE, false);
+                                    RADEON_VM_PTB_ALIGN(RADEON_VM_PTE_COUNT * 8),
+                                    RADEON_VM_PTB_ALIGN_SIZE, false);
 
                if (r == -ENOMEM) {
                        r = radeon_vm_evict(rdev, vm);