drm/xe/vm: Don't pin the vm_resv during validation

The pinning has the odd side-effect that unlocking *any* resv
during validation triggers an "unlocking pinned lock" warning.

Cc: Matthew Brost <matthew.brost@intel.com>
Fixes: 5cc3325 ("drm/xe: Rework eviction rejection of bound external bos")
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Link: https://lore.kernel.org/r/20250821143045.106005-2-thomas.hellstrom@linux.intel.com
(cherry picked from commit 0a51bf3)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

Author: Thomas Hellström

drivers/gpu/drm/xe/xe_bo.c

@@ -2438,7 +2438,6 @@ int xe_bo_validate(struct xe_bo *bo, struct xe_vm *vm, bool allow_res_evict)
 		.no_wait_gpu = false,
 		.gfp_retry_mayfail = true,
 	};
-	struct pin_cookie cookie;
 	int ret;
 
 	if (vm) {
@@ -2449,10 +2448,10 @@ int xe_bo_validate(struct xe_bo *bo, struct xe_vm *vm, bool allow_res_evict)
 		ctx.resv = xe_vm_resv(vm);
 	}
 
-	cookie = xe_vm_set_validating(vm, allow_res_evict);
+	xe_vm_set_validating(vm, allow_res_evict);
 	trace_xe_bo_validate(bo);
 	ret = ttm_bo_validate(&bo->ttm, &bo->placement, &ctx);
-	xe_vm_clear_validating(vm, allow_res_evict, cookie);
+	xe_vm_clear_validating(vm, allow_res_evict);
 
 	return ret;
 }

drivers/gpu/drm/xe/xe_vm.h

@@ -315,40 +315,29 @@ void xe_vm_snapshot_free(struct xe_vm_snapshot *snap);
  * Register this task as currently making bos resident for the vm. Intended
  * to avoid eviction by the same task of shared bos bound to the vm.
  * Call with the vm's resv lock held.
- *
- * Return: A pin cookie that should be used for xe_vm_clear_validating().
  */
-static inline struct pin_cookie xe_vm_set_validating(struct xe_vm *vm,
-						     bool allow_res_evict)
+static inline void xe_vm_set_validating(struct xe_vm *vm, bool allow_res_evict)
 {
-	struct pin_cookie cookie = {};
-
 	if (vm && !allow_res_evict) {
 		xe_vm_assert_held(vm);
-		cookie = lockdep_pin_lock(&xe_vm_resv(vm)->lock.base);
 		/* Pairs with READ_ONCE in xe_vm_is_validating() */
 		WRITE_ONCE(vm->validating, current);
 	}
-
-	return cookie;
 }
 
 /**
  * xe_vm_clear_validating() - Unregister this task as currently making bos resident
  * @vm: Pointer to the vm or NULL
  * @allow_res_evict: Eviction from @vm was allowed. Must be set to the same
  * value as for xe_vm_set_validation().
- * @cookie: Cookie obtained from xe_vm_set_validating().
  *
  * Register this task as currently making bos resident for the vm. Intended
  * to avoid eviction by the same task of shared bos bound to the vm.
  * Call with the vm's resv lock held.
  */
-static inline void xe_vm_clear_validating(struct xe_vm *vm, bool allow_res_evict,
-					  struct pin_cookie cookie)
+static inline void xe_vm_clear_validating(struct xe_vm *vm, bool allow_res_evict)
 {
 	if (vm && !allow_res_evict) {
-		lockdep_unpin_lock(&xe_vm_resv(vm)->lock.base, cookie);
 		/* Pairs with READ_ONCE in xe_vm_is_validating() */
 		WRITE_ONCE(vm->validating, NULL);
 	}