Merge v6.18.40linux-rolling-lts

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 50 insertions, 10 deletions

diff --git a/drivers/gpu/drm/xe/xe_pt.c b/drivers/gpu/drm/xe/xe_pt.c
index a21383fba1e8..1f0262adc3ae 100644
--- a/drivers/gpu/drm/xe/xe_pt.c
+++ b/drivers/gpu/drm/xe/xe_pt.c
@@ -860,13 +860,21 @@ static int xe_pt_zap_ptes_entry(struct xe_ptw *parent, pgoff_t offset,
 {
 	struct xe_pt_zap_ptes_walk *xe_walk =
 		container_of(walk, typeof(*xe_walk), base);
-	struct xe_pt *xe_child = container_of(*child, typeof(*xe_child), base);
+	struct xe_pt *xe_child;
 	pgoff_t end_offset;
 
-	XE_WARN_ON(!*child);
 	XE_WARN_ON(!level);
 
 	/*
+	 * Below would be unexpected behavior that needs to be root caused
+	 * but better warn and bail than crash the driver.
+	 */
+	if (XE_WARN_ON(!*child))
+		return 0;
+
+	xe_child = container_of(*child, typeof(*xe_child), base);
+
+	/*
 	 * Note that we're called from an entry callback, and we're dealing
 	 * with the child of that entry rather than the parent, so need to
 	 * adjust level down.
@@ -1053,7 +1061,7 @@ static void xe_pt_commit_locks_assert(struct xe_vma *vma)
 	xe_pt_commit_prepare_locks_assert(vma);
 
 	if (xe_vma_is_userptr(vma))
-		xe_svm_assert_held_read(vm);
+		xe_svm_assert_held_read_or_inject_write(vm);
 }
 
 static void xe_pt_commit(struct xe_vma *vma,
@@ -1381,6 +1389,38 @@ static int xe_pt_pre_commit(struct xe_migrate_pt_update *pt_update)
 }
 
 #if IS_ENABLED(CONFIG_DRM_GPUSVM)
+/*
+ * Acquire/release the svm notifier_lock around xe_pt_svm_userptr_pre_commit()
+ * and the matching late release in xe_pt_update_ops_run(). Read mode by
+ * default; write mode when CONFIG_DRM_XE_USERPTR_INVAL_INJECT is on,
+ * because a userptr op in this critical section may invoke the injected
+ * xe_vma_userptr_force_invalidate() path that calls
+ * drm_gpusvm_unmap_pages() with ctx->in_notifier=true, which requires the
+ * lock held for write.
+ */
+static void xe_pt_svm_userptr_notifier_lock(struct xe_vm *vm)
+{
+#if IS_ENABLED(CONFIG_DRM_XE_USERPTR_INVAL_INJECT)
+	down_write(&vm->svm.gpusvm.notifier_lock);
+#else
+	xe_svm_notifier_lock(vm);
+#endif
+}
+
+static void xe_pt_svm_userptr_notifier_unlock(struct xe_vm *vm)
+{
+#if IS_ENABLED(CONFIG_DRM_XE_USERPTR_INVAL_INJECT)
+	up_write(&vm->svm.gpusvm.notifier_lock);
+#else
+	xe_svm_notifier_unlock(vm);
+#endif
+}
+#else
+static inline void xe_pt_svm_userptr_notifier_lock(struct xe_vm *vm) { }
+static inline void xe_pt_svm_userptr_notifier_unlock(struct xe_vm *vm) { }
+#endif
+
+#if IS_ENABLED(CONFIG_DRM_GPUSVM)
 #ifdef CONFIG_DRM_XE_USERPTR_INVAL_INJECT
 
 static bool xe_pt_userptr_inject_eagain(struct xe_userptr_vma *uvma)
@@ -1411,7 +1451,7 @@ static int vma_check_userptr(struct xe_vm *vm, struct xe_vma *vma,
 	struct xe_userptr_vma *uvma;
 	unsigned long notifier_seq;
 
-	xe_svm_assert_held_read(vm);
+	xe_svm_assert_held_read_or_inject_write(vm);
 
 	if (!xe_vma_is_userptr(vma))
 		return 0;
@@ -1441,7 +1481,7 @@ static int op_check_svm_userptr(struct xe_vm *vm, struct xe_vma_op *op,
 {
 	int err = 0;
 
-	xe_svm_assert_held_read(vm);
+	xe_svm_assert_held_read_or_inject_write(vm);
 
 	switch (op->base.op) {
 	case DRM_GPUVA_OP_MAP:
@@ -1513,12 +1553,12 @@ static int xe_pt_svm_userptr_pre_commit(struct xe_migrate_pt_update *pt_update)
 	if (err)
 		return err;
 
-	xe_svm_notifier_lock(vm);
+	xe_pt_svm_userptr_notifier_lock(vm);
 
 	list_for_each_entry(op, &vops->list, link) {
 		err = op_check_svm_userptr(vm, op, pt_update_ops);
 		if (err) {
-			xe_svm_notifier_unlock(vm);
+			xe_pt_svm_userptr_notifier_unlock(vm);
 			break;
 		}
 	}
@@ -2184,7 +2224,7 @@ static void bind_op_commit(struct xe_vm *vm, struct xe_tile *tile,
 			   vma->tile_invalidated & ~BIT(tile->id));
 	vma->tile_staged &= ~BIT(tile->id);
 	if (xe_vma_is_userptr(vma)) {
-		xe_svm_assert_held_read(vm);
+		xe_svm_assert_held_read_or_inject_write(vm);
 		to_userptr_vma(vma)->userptr.initial_bind = true;
 	}
 
@@ -2220,7 +2260,7 @@ static void unbind_op_commit(struct xe_vm *vm, struct xe_tile *tile,
 	if (!vma->tile_present) {
 		list_del_init(&vma->combined_links.rebind);
 		if (xe_vma_is_userptr(vma)) {
-			xe_svm_assert_held_read(vm);
+			xe_svm_assert_held_read_or_inject_write(vm);
 
 			spin_lock(&vm->userptr.invalidated_lock);
 			list_del_init(&to_userptr_vma(vma)->userptr.invalidate_link);
@@ -2509,7 +2549,7 @@ xe_pt_update_ops_run(struct xe_tile *tile, struct xe_vma_ops *vops)
 	}
 
 	if (pt_update_ops->needs_svm_lock)
-		xe_svm_notifier_unlock(vm);
+		xe_pt_svm_userptr_notifier_unlock(vm);
 
 	xe_tlb_inval_job_put(mjob);
 	xe_tlb_inval_job_put(ijob);