drm/ttm: TTM fault handler helpers

With the vmwgfx dirty tracking, the default TTM fault handler is not
completely sufficient (vmwgfx need to modify the vma->vm_flags member,
and also needs to restrict the number of prefaults).

We also want to replicate the new ttm_bo_vm_reserve() functionality

So start turning the TTM vm code into helpers: ttm_bo_vm_fault_reserved()
and ttm_bo_vm_reserve(), and provide a default TTM fault handler for other
drivers to use.

Cc: "Christian König" <christian.koenig@amd.com>

Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: "Christian König" <christian.koenig@amd.com> #v1

1 files changed, 10 insertions, 0 deletions

diff --git a/include/drm/ttm/ttm_bo_api.h b/include/drm/ttm/ttm_bo_api.h
index 49d9cdfc58f2..435d02f719a8 100644
--- a/include/drm/ttm/ttm_bo_api.h
+++ b/include/drm/ttm/ttm_bo_api.h
@@ -768,4 +768,14 @@ int ttm_bo_swapout(struct ttm_bo_global *glob,
                         struct ttm_operation_ctx *ctx);
 void ttm_bo_swapout_all(struct ttm_bo_device *bdev);
 int ttm_bo_wait_unreserved(struct ttm_buffer_object *bo);
+
+/* Default number of pre-faulted pages in the TTM fault handler */
+#define TTM_BO_VM_NUM_PREFAULT 16
+
+vm_fault_t ttm_bo_vm_reserve(struct ttm_buffer_object *bo,
+                             struct vm_fault *vmf);
+
+vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf,
+                                    pgprot_t prot,
+                                    pgoff_t num_prefault);
 #endif