drm/gpuvm: Add locking helpers

For UNMAP/REMAP steps we could be needing to lock objects that are not
explicitly listed in the VM_BIND ioctl in order to tear-down unmapped
VAs.  These helpers handle locking/preparing the needed objects.

Note that these functions do not strictly require the VM changes to be
applied before the next drm_gpuvm_sm_map_lock()/_unmap_lock() call.  In
the case that VM changes from an earlier drm_gpuvm_sm_map()/_unmap()
call result in a differing sequence of steps when the VM changes are
actually applied, it will be the same set of GEM objects involved, so
the locking is still correct.

v2: Rename to drm_gpuvm_sm_*_exec_locked() [Danilo]
v3: Expand comments to show expected usage, and explain how the usage
    is safe in the case of overlapping driver VM_BIND ops.

Signed-off-by: Rob Clark <[email protected]>
Tested-by: Antonino Maniscalco <[email protected]>
Reviewed-by: Antonino Maniscalco <[email protected]>
Acked-by: Danilo Krummrich <[email protected]>
Patchwork: https://patchwork.freedesktop.org/patch/661458/

1 files changed, 8 insertions, 0 deletions

diff --git a/include/drm/drm_gpuvm.h b/include/drm/drm_gpuvm.h
index 2a9629377633..274532facfd6 100644
--- a/include/drm/drm_gpuvm.h
+++ b/include/drm/drm_gpuvm.h
@@ -1211,6 +1211,14 @@ int drm_gpuvm_sm_map(struct drm_gpuvm *gpuvm, void *priv,
 int drm_gpuvm_sm_unmap(struct drm_gpuvm *gpuvm, void *priv,
 		       u64 addr, u64 range);
 
+int drm_gpuvm_sm_map_exec_lock(struct drm_gpuvm *gpuvm,
+			  struct drm_exec *exec, unsigned int num_fences,
+			  u64 req_addr, u64 req_range,
+			  struct drm_gem_object *obj, u64 offset);
+
+int drm_gpuvm_sm_unmap_exec_lock(struct drm_gpuvm *gpuvm, struct drm_exec *exec,
+				 u64 req_addr, u64 req_range);
+
 void drm_gpuva_map(struct drm_gpuvm *gpuvm,
 		   struct drm_gpuva *va,
 		   struct drm_gpuva_op_map *op);