1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * KUnit test suite for GEM objects backed by shmem buffers
  4 *
  5 * Copyright (C) 2023 Red Hat, Inc.
  6 *
  7 * Author: Marco Pagani <marpagan@redhat.com>
  8 */
  9
 10#include <linux/dma-buf.h>
 11#include <linux/iosys-map.h>
 12#include <linux/sizes.h>
 13
 14#include <kunit/test.h>
 15
 16#include <drm/drm_device.h>
 17#include <drm/drm_drv.h>
 18#include <drm/drm_gem.h>
 19#include <drm/drm_gem_shmem_helper.h>
 20#include <drm/drm_kunit_helpers.h>
 21
 22#define TEST_SIZE		SZ_1M
 23#define TEST_BYTE		0xae
 24
 25/*
 26 * Wrappers to avoid an explicit type casting when passing action
 27 * functions to kunit_add_action().
 28 */
 29static void kfree_wrapper(void *ptr)
 30{
 31	const void *obj = ptr;
 32
 33	kfree(obj);
 34}
 35
 36static void sg_free_table_wrapper(void *ptr)
 37{
 38	struct sg_table *sgt = ptr;
 39
 40	sg_free_table(sgt);
 41}
 42
 43static void drm_gem_shmem_free_wrapper(void *ptr)
 44{
 45	struct drm_gem_shmem_object *shmem = ptr;
 46
 47	drm_gem_shmem_free(shmem);
 48}
 49
 50/*
 51 * Test creating a shmem GEM object backed by shmem buffer. The test
 52 * case succeeds if the GEM object is successfully allocated with the
 53 * shmem file node and object functions attributes set, and the size
 54 * attribute is equal to the correct size.
 55 */
 56static void drm_gem_shmem_test_obj_create(struct kunit *test)
 57{
 58	struct drm_device *drm_dev = test->priv;
 59	struct drm_gem_shmem_object *shmem;
 60
 61	shmem = drm_gem_shmem_create(drm_dev, TEST_SIZE);
 62	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, shmem);
 63	KUNIT_EXPECT_EQ(test, shmem->base.size, TEST_SIZE);
 64	KUNIT_EXPECT_NOT_NULL(test, shmem->base.filp);
 65	KUNIT_EXPECT_NOT_NULL(test, shmem->base.funcs);
 66
 67	drm_gem_shmem_free(shmem);
 68}
 69
 70/*
 71 * Test creating a shmem GEM object from a scatter/gather table exported
 72 * via a DMA-BUF. The test case succeed if the GEM object is successfully
 73 * created with the shmem file node attribute equal to NULL and the sgt
 74 * attribute pointing to the scatter/gather table that has been imported.
 75 */
 76static void drm_gem_shmem_test_obj_create_private(struct kunit *test)
 77{
 78	struct drm_device *drm_dev = test->priv;
 79	struct drm_gem_shmem_object *shmem;
 80	struct drm_gem_object *gem_obj;
 81	struct dma_buf buf_mock;
 82	struct dma_buf_attachment attach_mock;
 83	struct sg_table *sgt;
 84	char *buf;
 85	int ret;
 86
 87	/* Create a mock scatter/gather table */
 88	buf = kunit_kzalloc(test, TEST_SIZE, GFP_KERNEL);
 89	KUNIT_ASSERT_NOT_NULL(test, buf);
 90
 91	sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
 92	KUNIT_ASSERT_NOT_NULL(test, sgt);
 93
 94	ret = kunit_add_action_or_reset(test, kfree_wrapper, sgt);
 95	KUNIT_ASSERT_EQ(test, ret, 0);
 96
 97	ret = sg_alloc_table(sgt, 1, GFP_KERNEL);
 98	KUNIT_ASSERT_EQ(test, ret, 0);
 99
100	ret = kunit_add_action_or_reset(test, sg_free_table_wrapper, sgt);
101	KUNIT_ASSERT_EQ(test, ret, 0);
102
103	sg_init_one(sgt->sgl, buf, TEST_SIZE);
104
105	/* Init a mock DMA-BUF */
106	buf_mock.size = TEST_SIZE;
107	attach_mock.dmabuf = &buf_mock;
108
109	gem_obj = drm_gem_shmem_prime_import_sg_table(drm_dev, &attach_mock, sgt);
110	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, gem_obj);
111	KUNIT_EXPECT_EQ(test, gem_obj->size, TEST_SIZE);
112	KUNIT_EXPECT_NULL(test, gem_obj->filp);
113	KUNIT_EXPECT_NOT_NULL(test, gem_obj->funcs);
114
115	/* The scatter/gather table will be freed by drm_gem_shmem_free */
116	kunit_remove_action(test, sg_free_table_wrapper, sgt);
117	kunit_remove_action(test, kfree_wrapper, sgt);
118
119	shmem = to_drm_gem_shmem_obj(gem_obj);
120	KUNIT_EXPECT_PTR_EQ(test, shmem->sgt, sgt);
121
122	drm_gem_shmem_free(shmem);
123}
124
125/*
126 * Test pinning backing pages for a shmem GEM object. The test case
127 * succeeds if a suitable number of backing pages are allocated, and
128 * the pages table counter attribute is increased by one.
129 */
130static void drm_gem_shmem_test_pin_pages(struct kunit *test)
131{
132	struct drm_device *drm_dev = test->priv;
133	struct drm_gem_shmem_object *shmem;
134	int i, ret;
135
136	shmem = drm_gem_shmem_create(drm_dev, TEST_SIZE);
137	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, shmem);
138	KUNIT_EXPECT_NULL(test, shmem->pages);
139	KUNIT_EXPECT_EQ(test, shmem->pages_use_count, 0);
140
141	ret = kunit_add_action_or_reset(test, drm_gem_shmem_free_wrapper, shmem);
142	KUNIT_ASSERT_EQ(test, ret, 0);
143
144	ret = drm_gem_shmem_pin(shmem);
145	KUNIT_ASSERT_EQ(test, ret, 0);
146	KUNIT_ASSERT_NOT_NULL(test, shmem->pages);
147	KUNIT_EXPECT_EQ(test, shmem->pages_use_count, 1);
148
149	for (i = 0; i < (shmem->base.size >> PAGE_SHIFT); i++)
150		KUNIT_ASSERT_NOT_NULL(test, shmem->pages[i]);
151
152	drm_gem_shmem_unpin(shmem);
153	KUNIT_EXPECT_NULL(test, shmem->pages);
154	KUNIT_EXPECT_EQ(test, shmem->pages_use_count, 0);
155}
156
157/*
158 * Test creating a virtual mapping for a shmem GEM object. The test
159 * case succeeds if the backing memory is mapped and the reference
160 * counter for virtual mapping is increased by one. Moreover, the test
161 * case writes and then reads a test pattern over the mapped memory.
162 */
163static void drm_gem_shmem_test_vmap(struct kunit *test)
164{
165	struct drm_device *drm_dev = test->priv;
166	struct drm_gem_shmem_object *shmem;
167	struct iosys_map map;
168	int ret, i;
169
170	shmem = drm_gem_shmem_create(drm_dev, TEST_SIZE);
171	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, shmem);
172	KUNIT_EXPECT_NULL(test, shmem->vaddr);
173	KUNIT_EXPECT_EQ(test, shmem->vmap_use_count, 0);
174
175	ret = kunit_add_action_or_reset(test, drm_gem_shmem_free_wrapper, shmem);
176	KUNIT_ASSERT_EQ(test, ret, 0);
177
178	ret = drm_gem_shmem_vmap(shmem, &map);
179	KUNIT_ASSERT_EQ(test, ret, 0);
180	KUNIT_ASSERT_NOT_NULL(test, shmem->vaddr);
181	KUNIT_ASSERT_FALSE(test, iosys_map_is_null(&map));
182	KUNIT_EXPECT_EQ(test, shmem->vmap_use_count, 1);
183
184	iosys_map_memset(&map, 0, TEST_BYTE, TEST_SIZE);
185	for (i = 0; i < TEST_SIZE; i++)
186		KUNIT_EXPECT_EQ(test, iosys_map_rd(&map, i, u8), TEST_BYTE);
187
188	drm_gem_shmem_vunmap(shmem, &map);
189	KUNIT_EXPECT_NULL(test, shmem->vaddr);
190	KUNIT_EXPECT_EQ(test, shmem->vmap_use_count, 0);
191}
192
193/*
194 * Test exporting a scatter/gather table of pinned pages suitable for
195 * PRIME usage from a shmem GEM object. The test case succeeds if a
196 * scatter/gather table large enough to accommodate the backing memory
197 * is successfully exported.
198 */
199static void drm_gem_shmem_test_get_pages_sgt(struct kunit *test)
200{
201	struct drm_device *drm_dev = test->priv;
202	struct drm_gem_shmem_object *shmem;
203	struct sg_table *sgt;
204	struct scatterlist *sg;
205	unsigned int si, len = 0;
206	int ret;
207
208	shmem = drm_gem_shmem_create(drm_dev, TEST_SIZE);
209	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, shmem);
210
211	ret = kunit_add_action_or_reset(test, drm_gem_shmem_free_wrapper, shmem);
212	KUNIT_ASSERT_EQ(test, ret, 0);
213
214	ret = drm_gem_shmem_pin(shmem);
215	KUNIT_ASSERT_EQ(test, ret, 0);
216
217	sgt = drm_gem_shmem_get_sg_table(shmem);
218	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, sgt);
219	KUNIT_EXPECT_NULL(test, shmem->sgt);
220
221	ret = kunit_add_action_or_reset(test, sg_free_table_wrapper, sgt);
222	KUNIT_ASSERT_EQ(test, ret, 0);
223
224	for_each_sgtable_sg(sgt, sg, si) {
225		KUNIT_EXPECT_NOT_NULL(test, sg);
226		len += sg->length;
227	}
228
229	KUNIT_EXPECT_GE(test, len, TEST_SIZE);
230}
231
232/*
233 * Test pinning pages and exporting a scatter/gather table suitable for
234 * driver usage from a shmem GEM object. The test case succeeds if the
235 * backing pages are pinned and a scatter/gather table large enough to
236 * accommodate the backing memory is successfully exported.
237 */
238static void drm_gem_shmem_test_get_sg_table(struct kunit *test)
239{
240	struct drm_device *drm_dev = test->priv;
241	struct drm_gem_shmem_object *shmem;
242	struct sg_table *sgt;
243	struct scatterlist *sg;
244	unsigned int si, ret, len = 0;
245
246	shmem = drm_gem_shmem_create(drm_dev, TEST_SIZE);
247	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, shmem);
248
249	ret = kunit_add_action_or_reset(test, drm_gem_shmem_free_wrapper, shmem);
250	KUNIT_ASSERT_EQ(test, ret, 0);
251
252	/* The scatter/gather table will be freed by drm_gem_shmem_free */
253	sgt = drm_gem_shmem_get_pages_sgt(shmem);
254	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, sgt);
255	KUNIT_ASSERT_NOT_NULL(test, shmem->pages);
256	KUNIT_EXPECT_EQ(test, shmem->pages_use_count, 1);
257	KUNIT_EXPECT_PTR_EQ(test, sgt, shmem->sgt);
258
259	for_each_sgtable_sg(sgt, sg, si) {
260		KUNIT_EXPECT_NOT_NULL(test, sg);
261		len += sg->length;
262	}
263
264	KUNIT_EXPECT_GE(test, len, TEST_SIZE);
265}
266
267/*
268 * Test updating the madvise state of a shmem GEM object. The test
269 * case checks that the function for setting madv updates it only if
270 * its current value is greater or equal than zero and returns false
271 * if it has a negative value.
272 */
273static void drm_gem_shmem_test_madvise(struct kunit *test)
274{
275	struct drm_device *drm_dev = test->priv;
276	struct drm_gem_shmem_object *shmem;
277	int ret;
278
279	shmem = drm_gem_shmem_create(drm_dev, TEST_SIZE);
280	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, shmem);
281	KUNIT_ASSERT_EQ(test, shmem->madv, 0);
282
283	ret = kunit_add_action_or_reset(test, drm_gem_shmem_free_wrapper, shmem);
284	KUNIT_ASSERT_EQ(test, ret, 0);
285
286	ret = drm_gem_shmem_madvise(shmem, 1);
287	KUNIT_EXPECT_TRUE(test, ret);
288	KUNIT_ASSERT_EQ(test, shmem->madv, 1);
289
290	/* Set madv to a negative value */
291	ret = drm_gem_shmem_madvise(shmem, -1);
292	KUNIT_EXPECT_FALSE(test, ret);
293	KUNIT_ASSERT_EQ(test, shmem->madv, -1);
294
295	/* Check that madv cannot be set back to a positive value */
296	ret = drm_gem_shmem_madvise(shmem, 0);
297	KUNIT_EXPECT_FALSE(test, ret);
298	KUNIT_ASSERT_EQ(test, shmem->madv, -1);
299}
300
301/*
302 * Test purging a shmem GEM object. First, assert that a newly created
303 * shmem GEM object is not purgeable. Then, set madvise to a positive
304 * value and call drm_gem_shmem_get_pages_sgt() to pin and dma-map the
305 * backing pages. Finally, assert that the shmem GEM object is now
306 * purgeable and purge it.
307 */
308static void drm_gem_shmem_test_purge(struct kunit *test)
309{
310	struct drm_device *drm_dev = test->priv;
311	struct drm_gem_shmem_object *shmem;
312	struct sg_table *sgt;
313	int ret;
314
315	shmem = drm_gem_shmem_create(drm_dev, TEST_SIZE);
316	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, shmem);
317
318	ret = kunit_add_action_or_reset(test, drm_gem_shmem_free_wrapper, shmem);
319	KUNIT_ASSERT_EQ(test, ret, 0);
320
321	ret = drm_gem_shmem_is_purgeable(shmem);
322	KUNIT_EXPECT_FALSE(test, ret);
323
324	ret = drm_gem_shmem_madvise(shmem, 1);
325	KUNIT_EXPECT_TRUE(test, ret);
326
327	/* The scatter/gather table will be freed by drm_gem_shmem_free */
328	sgt = drm_gem_shmem_get_pages_sgt(shmem);
329	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, sgt);
330
331	ret = drm_gem_shmem_is_purgeable(shmem);
332	KUNIT_EXPECT_TRUE(test, ret);
333
334	drm_gem_shmem_purge(shmem);
335	KUNIT_EXPECT_NULL(test, shmem->pages);
336	KUNIT_EXPECT_NULL(test, shmem->sgt);
337	KUNIT_EXPECT_EQ(test, shmem->madv, -1);
338}
339
340static int drm_gem_shmem_test_init(struct kunit *test)
341{
342	struct device *dev;
343	struct drm_device *drm_dev;
344
345	/* Allocate a parent device */
346	dev = drm_kunit_helper_alloc_device(test);
347	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, dev);
348
349	/*
350	 * The DRM core will automatically initialize the GEM core and create
351	 * a DRM Memory Manager object which provides an address space pool
352	 * for GEM objects allocation.
353	 */
354	drm_dev = __drm_kunit_helper_alloc_drm_device(test, dev, sizeof(*drm_dev),
355						      0, DRIVER_GEM);
356	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, drm_dev);
357
358	test->priv = drm_dev;
359
360	return 0;
361}
362
363static struct kunit_case drm_gem_shmem_test_cases[] = {
364	KUNIT_CASE(drm_gem_shmem_test_obj_create),
365	KUNIT_CASE(drm_gem_shmem_test_obj_create_private),
366	KUNIT_CASE(drm_gem_shmem_test_pin_pages),
367	KUNIT_CASE(drm_gem_shmem_test_vmap),
368	KUNIT_CASE(drm_gem_shmem_test_get_pages_sgt),
369	KUNIT_CASE(drm_gem_shmem_test_get_sg_table),
370	KUNIT_CASE(drm_gem_shmem_test_madvise),
371	KUNIT_CASE(drm_gem_shmem_test_purge),
372	{}
373};
374
375static struct kunit_suite drm_gem_shmem_suite = {
376	.name = "drm_gem_shmem",
377	.init = drm_gem_shmem_test_init,
378	.test_cases = drm_gem_shmem_test_cases
379};
380
381kunit_test_suite(drm_gem_shmem_suite);
382
383MODULE_LICENSE("GPL");