drm/ttm/tests: Add tests with mock resource managers

Add mock resource manager to test ttm_bo_validate() with non-system
placements. Update KConfig entry to enable DRM Buddy allocator, used
by the mock manager. Update move function to do more than just assign
a resource.
Signed-off-by: Karolina Stolarek <karolina.stolarek@intel.com>
Tested-by: Somalapuram, Amaranath <asomalap@amd.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Signed-off-by: Arunpravin Paneer Selvam <Arunpravin.PaneerSelvam@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/664791dbb7cbada29e705d2fcaf176023f1b8649.1718192625.git.karolina.stolarek@intel.com

drivers/gpu/drm/Kconfig

@@ -248,6 +248,7 @@ config DRM_TTM_KUNIT_TEST
         default n
         depends on DRM && KUNIT && MMU && (UML || COMPILE_TEST)
         select DRM_TTM
+        select DRM_BUDDY
         select DRM_EXPORT_FOR_TESTS if m
         select DRM_KUNIT_TEST_HELPERS
         default KUNIT_ALL_TESTS

drivers/gpu/drm/ttm/tests/Makefile

@@ -7,4 +7,5 @@ obj-$(CONFIG_DRM_TTM_KUNIT_TEST) += \
         ttm_tt_test.o \
         ttm_bo_test.o \
         ttm_bo_validate_test.o \
+        ttm_mock_manager.o \
         ttm_kunit_helpers.o

drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.c

@@ -27,8 +27,31 @@ static int mock_move(struct ttm_buffer_object *bo, bool evict,
 		     struct ttm_resource *new_mem,
 		     struct ttm_place *hop)
 {
-	bo->resource = new_mem;
+	struct ttm_resource *old_mem = bo->resource;
+
+	if (!old_mem || (old_mem->mem_type == TTM_PL_SYSTEM && !bo->ttm)) {
+		ttm_bo_move_null(bo, new_mem);
+		return 0;
+	}
+
+	if (bo->resource->mem_type == TTM_PL_VRAM &&
+	    new_mem->mem_type == TTM_PL_SYSTEM) {
+		hop->mem_type = TTM_PL_TT;
+		hop->flags = TTM_PL_FLAG_TEMPORARY;
+		hop->fpfn = 0;
+		hop->lpfn = 0;
+		return -EMULTIHOP;
+	}
+
+	if ((old_mem->mem_type == TTM_PL_SYSTEM &&
+	     new_mem->mem_type == TTM_PL_TT) ||
+	    (old_mem->mem_type == TTM_PL_TT &&
+	     new_mem->mem_type == TTM_PL_SYSTEM)) {
+		ttm_bo_move_null(bo, new_mem);
 		return 0;
+	}
+
+	return ttm_bo_move_memcpy(bo, ctx, new_mem);
 }
 
 struct ttm_device_funcs ttm_dev_funcs = {

drivers/gpu/drm/ttm/tests/ttm_mock_manager.c

+// SPDX-License-Identifier: GPL-2.0 AND MIT
+/*
+ * Copyright © 2023 Intel Corporation
+ */
+#include <drm/ttm/ttm_resource.h>
+#include <drm/ttm/ttm_device.h>
+#include <drm/ttm/ttm_placement.h>
+
+#include "ttm_mock_manager.h"
+
+static inline struct ttm_mock_manager *
+to_mock_mgr(struct ttm_resource_manager *man)
+{
+	return container_of(man, struct ttm_mock_manager, man);
+}
+
+static inline struct ttm_mock_resource *
+to_mock_mgr_resource(struct ttm_resource *res)
+{
+	return container_of(res, struct ttm_mock_resource, base);
+}
+
+static int ttm_mock_manager_alloc(struct ttm_resource_manager *man,
+				  struct ttm_buffer_object *bo,
+				  const struct ttm_place *place,
+				  struct ttm_resource **res)
+{
+	struct ttm_mock_manager *manager = to_mock_mgr(man);
+	struct ttm_mock_resource *mock_res;
+	struct drm_buddy *mm = &manager->mm;
+	u64 lpfn, fpfn, alloc_size;
+	int err;
+
+	mock_res = kzalloc(sizeof(*mock_res), GFP_KERNEL);
+
+	if (!mock_res)
+		return -ENOMEM;
+
+	fpfn = 0;
+	lpfn = man->size;
+
+	ttm_resource_init(bo, place, &mock_res->base);
+	INIT_LIST_HEAD(&mock_res->blocks);
+
+	if (place->flags & TTM_PL_FLAG_TOPDOWN)
+		mock_res->flags |= DRM_BUDDY_TOPDOWN_ALLOCATION;
+
+	if (place->flags & TTM_PL_FLAG_CONTIGUOUS)
+		mock_res->flags |= DRM_BUDDY_CONTIGUOUS_ALLOCATION;
+
+	alloc_size = (uint64_t)mock_res->base.size;
+	mutex_lock(&manager->lock);
+	err = drm_buddy_alloc_blocks(mm, fpfn, lpfn, alloc_size,
+				     manager->default_page_size,
+				     &mock_res->blocks,
+				     mock_res->flags);
+
+	if (err)
+		goto error_free_blocks;
+	mutex_unlock(&manager->lock);
+
+	*res = &mock_res->base;
+	return 0;
+
+error_free_blocks:
+	drm_buddy_free_list(mm, &mock_res->blocks, 0);
+	ttm_resource_fini(man, &mock_res->base);
+	mutex_unlock(&manager->lock);
+
+	return err;
+}
+
+static void ttm_mock_manager_free(struct ttm_resource_manager *man,
+				  struct ttm_resource *res)
+{
+	struct ttm_mock_manager *manager = to_mock_mgr(man);
+	struct ttm_mock_resource *mock_res = to_mock_mgr_resource(res);
+	struct drm_buddy *mm = &manager->mm;
+
+	mutex_lock(&manager->lock);
+	drm_buddy_free_list(mm, &mock_res->blocks, 0);
+	mutex_unlock(&manager->lock);
+
+	ttm_resource_fini(man, res);
+	kfree(mock_res);
+}
+
+static const struct ttm_resource_manager_func ttm_mock_manager_funcs = {
+	.alloc = ttm_mock_manager_alloc,
+	.free = ttm_mock_manager_free,
+};
+
+int ttm_mock_manager_init(struct ttm_device *bdev, u32 mem_type, u32 size)
+{
+	struct ttm_mock_manager *manager;
+	struct ttm_resource_manager *base;
+	int err;
+
+	manager = kzalloc(sizeof(*manager), GFP_KERNEL);
+	if (!manager)
+		return -ENOMEM;
+
+	mutex_init(&manager->lock);
+
+	err = drm_buddy_init(&manager->mm, size, PAGE_SIZE);
+
+	if (err) {
+		kfree(manager);
+		return err;
+	}
+
+	manager->default_page_size = PAGE_SIZE;
+	base = &manager->man;
+	base->func = &ttm_mock_manager_funcs;
+	base->use_tt = true;
+
+	ttm_resource_manager_init(base, bdev, size);
+	ttm_set_driver_manager(bdev, mem_type, base);
+	ttm_resource_manager_set_used(base, true);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ttm_mock_manager_init);
+
+void ttm_mock_manager_fini(struct ttm_device *bdev, u32 mem_type)
+{
+	struct ttm_resource_manager *man;
+	struct ttm_mock_manager *mock_man;
+	int err;
+
+	man = ttm_manager_type(bdev, mem_type);
+	mock_man = to_mock_mgr(man);
+
+	err = ttm_resource_manager_evict_all(bdev, man);
+	if (err)
+		return;
+
+	ttm_resource_manager_set_used(man, false);
+
+	mutex_lock(&mock_man->lock);
+	drm_buddy_fini(&mock_man->mm);
+	mutex_unlock(&mock_man->lock);
+
+	ttm_set_driver_manager(bdev, mem_type, NULL);
+}
+EXPORT_SYMBOL_GPL(ttm_mock_manager_fini);
+
+static int ttm_bad_manager_alloc(struct ttm_resource_manager *man,
+				 struct ttm_buffer_object *bo,
+				 const struct ttm_place *place,
+				 struct ttm_resource **res)
+{
+	return -ENOSPC;
+}
+
+static void ttm_bad_manager_free(struct ttm_resource_manager *man,
+				 struct ttm_resource *res)
+{
+}
+
+static bool ttm_bad_manager_compatible(struct ttm_resource_manager *man,
+				       struct ttm_resource *res,
+				       const struct ttm_place *place,
+				       size_t size)
+{
+	return true;
+}
+
+static const struct ttm_resource_manager_func ttm_bad_manager_funcs = {
+	.alloc = ttm_bad_manager_alloc,
+	.free = ttm_bad_manager_free,
+	.compatible = ttm_bad_manager_compatible
+};
+
+int ttm_bad_manager_init(struct ttm_device *bdev, u32 mem_type, u32 size)
+{
+	struct ttm_resource_manager *man;
+
+	man = kzalloc(sizeof(*man), GFP_KERNEL);
+	if (!man)
+		return -ENOMEM;
+
+	man->func = &ttm_bad_manager_funcs;
+
+	ttm_resource_manager_init(man, bdev, size);
+	ttm_set_driver_manager(bdev, mem_type, man);
+	ttm_resource_manager_set_used(man, true);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ttm_bad_manager_init);
+
+void ttm_bad_manager_fini(struct ttm_device *bdev, u32 mem_type)
+{
+	struct ttm_resource_manager *man;
+
+	man = ttm_manager_type(bdev, mem_type);
+
+	ttm_resource_manager_set_used(man, false);
+	ttm_set_driver_manager(bdev, mem_type, NULL);
+
+	kfree(man);
+}
+EXPORT_SYMBOL_GPL(ttm_bad_manager_fini);
+
+MODULE_LICENSE("GPL and additional rights");

drivers/gpu/drm/ttm/tests/ttm_mock_manager.h

+/* SPDX-License-Identifier: GPL-2.0 AND MIT */
+/*
+ * Copyright © 2023 Intel Corporation
+ */
+#ifndef TTM_MOCK_MANAGER_H
+#define TTM_MOCK_MANAGER_H
+
+#include <drm/drm_buddy.h>
+
+struct ttm_mock_manager {
+	struct ttm_resource_manager man;
+	struct drm_buddy mm;
+	u64 default_page_size;
+	/* protects allocations of mock buffer objects */
+	struct mutex lock;
+};
+
+struct ttm_mock_resource {
+	struct ttm_resource base;
+	struct list_head blocks;
+	unsigned long flags;
+};
+
+int ttm_mock_manager_init(struct ttm_device *bdev, u32 mem_type, u32 size);
+int ttm_bad_manager_init(struct ttm_device *bdev, u32 mem_type, u32 size);
+void ttm_mock_manager_fini(struct ttm_device *bdev, u32 mem_type);
+void ttm_bad_manager_fini(struct ttm_device *bdev, u32 mem_type);
+
+#endif // TTM_MOCK_MANAGER_H