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 MODULE_IMPORT_NS("EXPORTED_FOR_KUNIT_TESTING"); 23 24 #define TEST_SIZE SZ_1M 25 #define TEST_BYTE 0xae 26 27 /* 28 * Wrappers to avoid cast warnings when passing action functions 29 * directly to kunit_add_action(). 30 */ 31 KUNIT_DEFINE_ACTION_WRAPPER(kfree_wrapper, kfree, const void *); 32 33 KUNIT_DEFINE_ACTION_WRAPPER(sg_free_table_wrapper, sg_free_table, 34 struct sg_table *); 35 36 KUNIT_DEFINE_ACTION_WRAPPER(drm_gem_shmem_free_wrapper, drm_gem_shmem_free, 37 struct drm_gem_shmem_object *); 38 39 KUNIT_DEFINE_ACTION_WRAPPER(drm_gem_shmem_unpin_wrapper, drm_gem_shmem_unpin, 40 struct drm_gem_shmem_object *); 41 42 /* 43 * Test creating a shmem GEM object backed by shmem buffer. The test 44 * case succeeds if the GEM object is successfully allocated with the 45 * shmem file node and object functions attributes set, and the size 46 * attribute is equal to the correct size. 47 */ 48 static void drm_gem_shmem_test_obj_create(struct kunit *test) 49 { 50 struct drm_device *drm_dev = test->priv; 51 struct drm_gem_shmem_object *shmem; 52 53 shmem = drm_gem_shmem_create(drm_dev, TEST_SIZE); 54 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, shmem); 55 KUNIT_EXPECT_EQ(test, shmem->base.size, TEST_SIZE); 56 KUNIT_EXPECT_NOT_NULL(test, shmem->base.filp); 57 KUNIT_EXPECT_NOT_NULL(test, shmem->base.funcs); 58 59 drm_gem_shmem_free(shmem); 60 } 61 62 /* 63 * Test creating a shmem GEM object from a scatter/gather table exported 64 * via a DMA-BUF. The test case succeed if the GEM object is successfully 65 * created with the shmem file node attribute equal to NULL and the sgt 66 * attribute pointing to the scatter/gather table that has been imported. 67 */ 68 static void drm_gem_shmem_test_obj_create_private(struct kunit *test) 69 { 70 struct drm_device *drm_dev = test->priv; 71 struct drm_gem_shmem_object *shmem; 72 struct drm_gem_object *gem_obj; 73 struct dma_buf buf_mock; 74 struct dma_buf_attachment attach_mock; 75 struct sg_table *sgt; 76 char *buf; 77 int ret; 78 79 /* Create a mock scatter/gather table */ 80 buf = kunit_kzalloc(test, TEST_SIZE, GFP_KERNEL); 81 KUNIT_ASSERT_NOT_NULL(test, buf); 82 83 sgt = kzalloc(sizeof(*sgt), GFP_KERNEL); 84 KUNIT_ASSERT_NOT_NULL(test, sgt); 85 86 ret = kunit_add_action_or_reset(test, kfree_wrapper, sgt); 87 KUNIT_ASSERT_EQ(test, ret, 0); 88 89 ret = sg_alloc_table(sgt, 1, GFP_KERNEL); 90 KUNIT_ASSERT_EQ(test, ret, 0); 91 92 ret = kunit_add_action_or_reset(test, sg_free_table_wrapper, sgt); 93 KUNIT_ASSERT_EQ(test, ret, 0); 94 95 sg_init_one(sgt->sgl, buf, TEST_SIZE); 96 97 /* 98 * Set the DMA mask to 64-bits and map the sgtables 99 * otherwise drm_gem_shmem_free will cause a warning 100 * on debug kernels. 101 */ 102 ret = dma_set_mask(drm_dev->dev, DMA_BIT_MASK(64)); 103 KUNIT_ASSERT_EQ(test, ret, 0); 104 105 ret = dma_map_sgtable(drm_dev->dev, sgt, DMA_BIDIRECTIONAL, 0); 106 KUNIT_ASSERT_EQ(test, ret, 0); 107 108 /* Init a mock DMA-BUF */ 109 buf_mock.size = TEST_SIZE; 110 attach_mock.dmabuf = &buf_mock; 111 112 gem_obj = drm_gem_shmem_prime_import_sg_table(drm_dev, &attach_mock, sgt); 113 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, gem_obj); 114 KUNIT_EXPECT_EQ(test, gem_obj->size, TEST_SIZE); 115 KUNIT_EXPECT_NULL(test, gem_obj->filp); 116 KUNIT_EXPECT_NOT_NULL(test, gem_obj->funcs); 117 118 /* The scatter/gather table will be freed by drm_gem_shmem_free */ 119 kunit_remove_action(test, sg_free_table_wrapper, sgt); 120 kunit_remove_action(test, kfree_wrapper, sgt); 121 122 shmem = to_drm_gem_shmem_obj(gem_obj); 123 KUNIT_EXPECT_PTR_EQ(test, shmem->sgt, sgt); 124 125 drm_gem_shmem_free(shmem); 126 } 127 128 /* 129 * Test pinning backing pages for a shmem GEM object. The test case 130 * succeeds if a suitable number of backing pages are allocated, and 131 * the pages table counter attribute is increased by one. 132 */ 133 static void drm_gem_shmem_test_pin_pages(struct kunit *test) 134 { 135 struct drm_device *drm_dev = test->priv; 136 struct drm_gem_shmem_object *shmem; 137 int i, ret; 138 139 shmem = drm_gem_shmem_create(drm_dev, TEST_SIZE); 140 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, shmem); 141 KUNIT_EXPECT_NULL(test, shmem->pages); 142 KUNIT_EXPECT_EQ(test, refcount_read(&shmem->pages_use_count), 0); 143 144 ret = kunit_add_action_or_reset(test, drm_gem_shmem_free_wrapper, shmem); 145 KUNIT_ASSERT_EQ(test, ret, 0); 146 147 ret = drm_gem_shmem_pin(shmem); 148 KUNIT_ASSERT_EQ(test, ret, 0); 149 KUNIT_ASSERT_NOT_NULL(test, shmem->pages); 150 KUNIT_EXPECT_EQ(test, refcount_read(&shmem->pages_use_count), 1); 151 152 for (i = 0; i < (shmem->base.size >> PAGE_SHIFT); i++) 153 KUNIT_ASSERT_NOT_NULL(test, shmem->pages[i]); 154 155 drm_gem_shmem_unpin(shmem); 156 KUNIT_EXPECT_NULL(test, shmem->pages); 157 KUNIT_EXPECT_EQ(test, refcount_read(&shmem->pages_use_count), 0); 158 } 159 160 /* 161 * Test creating a virtual mapping for a shmem GEM object. The test 162 * case succeeds if the backing memory is mapped and the reference 163 * counter for virtual mapping is increased by one. Moreover, the test 164 * case writes and then reads a test pattern over the mapped memory. 165 */ 166 static void drm_gem_shmem_test_vmap(struct kunit *test) 167 { 168 struct drm_device *drm_dev = test->priv; 169 struct drm_gem_shmem_object *shmem; 170 struct iosys_map map; 171 int ret, i; 172 173 shmem = drm_gem_shmem_create(drm_dev, TEST_SIZE); 174 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, shmem); 175 KUNIT_EXPECT_NULL(test, shmem->vaddr); 176 KUNIT_EXPECT_EQ(test, refcount_read(&shmem->vmap_use_count), 0); 177 178 ret = kunit_add_action_or_reset(test, drm_gem_shmem_free_wrapper, shmem); 179 KUNIT_ASSERT_EQ(test, ret, 0); 180 181 ret = drm_gem_shmem_vmap(shmem, &map); 182 KUNIT_ASSERT_EQ(test, ret, 0); 183 KUNIT_ASSERT_NOT_NULL(test, shmem->vaddr); 184 KUNIT_ASSERT_FALSE(test, iosys_map_is_null(&map)); 185 KUNIT_EXPECT_EQ(test, refcount_read(&shmem->vmap_use_count), 1); 186 187 iosys_map_memset(&map, 0, TEST_BYTE, TEST_SIZE); 188 for (i = 0; i < TEST_SIZE; i++) 189 KUNIT_EXPECT_EQ(test, iosys_map_rd(&map, i, u8), TEST_BYTE); 190 191 drm_gem_shmem_vunmap(shmem, &map); 192 KUNIT_EXPECT_NULL(test, shmem->vaddr); 193 KUNIT_EXPECT_EQ(test, refcount_read(&shmem->vmap_use_count), 0); 194 } 195 196 /* 197 * Test exporting a scatter/gather table of pinned pages suitable for 198 * PRIME usage from a shmem GEM object. The test case succeeds if a 199 * scatter/gather table large enough to accommodate the backing memory 200 * is successfully exported. 201 */ 202 static void drm_gem_shmem_test_get_sg_table(struct kunit *test) 203 { 204 struct drm_device *drm_dev = test->priv; 205 struct drm_gem_shmem_object *shmem; 206 struct sg_table *sgt; 207 struct scatterlist *sg; 208 unsigned int si, len = 0; 209 int ret; 210 211 shmem = drm_gem_shmem_create(drm_dev, TEST_SIZE); 212 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, shmem); 213 214 ret = kunit_add_action_or_reset(test, drm_gem_shmem_free_wrapper, shmem); 215 KUNIT_ASSERT_EQ(test, ret, 0); 216 217 ret = drm_gem_shmem_pin(shmem); 218 KUNIT_ASSERT_EQ(test, ret, 0); 219 220 ret = kunit_add_action_or_reset(test, drm_gem_shmem_unpin_wrapper, shmem); 221 KUNIT_ASSERT_EQ(test, ret, 0); 222 223 sgt = drm_gem_shmem_get_sg_table(shmem); 224 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, sgt); 225 KUNIT_EXPECT_NULL(test, shmem->sgt); 226 227 ret = kunit_add_action_or_reset(test, kfree_wrapper, sgt); 228 KUNIT_ASSERT_EQ(test, ret, 0); 229 230 ret = kunit_add_action_or_reset(test, sg_free_table_wrapper, sgt); 231 KUNIT_ASSERT_EQ(test, ret, 0); 232 233 for_each_sgtable_sg(sgt, sg, si) { 234 KUNIT_EXPECT_NOT_NULL(test, sg); 235 len += sg->length; 236 } 237 238 KUNIT_EXPECT_GE(test, len, TEST_SIZE); 239 } 240 241 /* 242 * Test pinning pages and exporting a scatter/gather table suitable for 243 * driver usage from a shmem GEM object. The test case succeeds if the 244 * backing pages are pinned and a scatter/gather table large enough to 245 * accommodate the backing memory is successfully exported. 246 */ 247 static void drm_gem_shmem_test_get_pages_sgt(struct kunit *test) 248 { 249 struct drm_device *drm_dev = test->priv; 250 struct drm_gem_shmem_object *shmem; 251 struct sg_table *sgt; 252 struct scatterlist *sg; 253 unsigned int si, ret, len = 0; 254 255 shmem = drm_gem_shmem_create(drm_dev, TEST_SIZE); 256 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, shmem); 257 258 ret = kunit_add_action_or_reset(test, drm_gem_shmem_free_wrapper, shmem); 259 KUNIT_ASSERT_EQ(test, ret, 0); 260 261 /* The scatter/gather table will be freed by drm_gem_shmem_free */ 262 sgt = drm_gem_shmem_get_pages_sgt(shmem); 263 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, sgt); 264 KUNIT_ASSERT_NOT_NULL(test, shmem->pages); 265 KUNIT_EXPECT_EQ(test, refcount_read(&shmem->pages_use_count), 1); 266 KUNIT_EXPECT_PTR_EQ(test, sgt, shmem->sgt); 267 268 for_each_sgtable_sg(sgt, sg, si) { 269 KUNIT_EXPECT_NOT_NULL(test, sg); 270 len += sg->length; 271 } 272 273 KUNIT_EXPECT_GE(test, len, TEST_SIZE); 274 } 275 276 /* 277 * Test updating the madvise state of a shmem GEM object. The test 278 * case checks that the function for setting madv updates it only if 279 * its current value is greater or equal than zero and returns false 280 * if it has a negative value. 281 */ 282 static void drm_gem_shmem_test_madvise(struct kunit *test) 283 { 284 struct drm_device *drm_dev = test->priv; 285 struct drm_gem_shmem_object *shmem; 286 int ret; 287 288 shmem = drm_gem_shmem_create(drm_dev, TEST_SIZE); 289 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, shmem); 290 KUNIT_ASSERT_EQ(test, shmem->madv, 0); 291 292 ret = kunit_add_action_or_reset(test, drm_gem_shmem_free_wrapper, shmem); 293 KUNIT_ASSERT_EQ(test, ret, 0); 294 295 ret = drm_gem_shmem_madvise(shmem, 1); 296 KUNIT_EXPECT_TRUE(test, ret); 297 KUNIT_ASSERT_EQ(test, shmem->madv, 1); 298 299 /* Set madv to a negative value */ 300 ret = drm_gem_shmem_madvise(shmem, -1); 301 KUNIT_EXPECT_FALSE(test, ret); 302 KUNIT_ASSERT_EQ(test, shmem->madv, -1); 303 304 /* Check that madv cannot be set back to a positive value */ 305 ret = drm_gem_shmem_madvise(shmem, 0); 306 KUNIT_EXPECT_FALSE(test, ret); 307 KUNIT_ASSERT_EQ(test, shmem->madv, -1); 308 } 309 310 /* 311 * Test purging a shmem GEM object. First, assert that a newly created 312 * shmem GEM object is not purgeable. Then, set madvise to a positive 313 * value and call drm_gem_shmem_get_pages_sgt() to pin and dma-map the 314 * backing pages. Finally, assert that the shmem GEM object is now 315 * purgeable and purge it. 316 */ 317 static void drm_gem_shmem_test_purge(struct kunit *test) 318 { 319 struct drm_device *drm_dev = test->priv; 320 struct drm_gem_shmem_object *shmem; 321 struct sg_table *sgt; 322 int ret; 323 324 shmem = drm_gem_shmem_create(drm_dev, TEST_SIZE); 325 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, shmem); 326 327 ret = kunit_add_action_or_reset(test, drm_gem_shmem_free_wrapper, shmem); 328 KUNIT_ASSERT_EQ(test, ret, 0); 329 330 ret = drm_gem_shmem_is_purgeable(shmem); 331 KUNIT_EXPECT_FALSE(test, ret); 332 333 ret = drm_gem_shmem_madvise(shmem, 1); 334 KUNIT_EXPECT_TRUE(test, ret); 335 336 /* The scatter/gather table will be freed by drm_gem_shmem_free */ 337 sgt = drm_gem_shmem_get_pages_sgt(shmem); 338 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, sgt); 339 340 ret = drm_gem_shmem_is_purgeable(shmem); 341 KUNIT_EXPECT_TRUE(test, ret); 342 343 ret = drm_gem_shmem_purge(shmem); 344 KUNIT_ASSERT_EQ(test, ret, 0); 345 346 KUNIT_EXPECT_NULL(test, shmem->pages); 347 KUNIT_EXPECT_NULL(test, shmem->sgt); 348 KUNIT_EXPECT_EQ(test, shmem->madv, -1); 349 } 350 351 static int drm_gem_shmem_test_init(struct kunit *test) 352 { 353 struct device *dev; 354 struct drm_device *drm_dev; 355 356 /* Allocate a parent device */ 357 dev = drm_kunit_helper_alloc_device(test); 358 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, dev); 359 360 /* 361 * The DRM core will automatically initialize the GEM core and create 362 * a DRM Memory Manager object which provides an address space pool 363 * for GEM objects allocation. 364 */ 365 drm_dev = __drm_kunit_helper_alloc_drm_device(test, dev, sizeof(*drm_dev), 366 0, DRIVER_GEM); 367 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, drm_dev); 368 369 test->priv = drm_dev; 370 371 return 0; 372 } 373 374 static struct kunit_case drm_gem_shmem_test_cases[] = { 375 KUNIT_CASE(drm_gem_shmem_test_obj_create), 376 KUNIT_CASE(drm_gem_shmem_test_obj_create_private), 377 KUNIT_CASE(drm_gem_shmem_test_pin_pages), 378 KUNIT_CASE(drm_gem_shmem_test_vmap), 379 KUNIT_CASE(drm_gem_shmem_test_get_sg_table), 380 KUNIT_CASE(drm_gem_shmem_test_get_pages_sgt), 381 KUNIT_CASE(drm_gem_shmem_test_madvise), 382 KUNIT_CASE(drm_gem_shmem_test_purge), 383 {} 384 }; 385 386 static struct kunit_suite drm_gem_shmem_suite = { 387 .name = "drm_gem_shmem", 388 .init = drm_gem_shmem_test_init, 389 .test_cases = drm_gem_shmem_test_cases 390 }; 391 392 kunit_test_suite(drm_gem_shmem_suite); 393 394 MODULE_DESCRIPTION("KUnit test suite for GEM objects backed by shmem buffers"); 395 MODULE_LICENSE("GPL"); 396