1 /* 2 * SPDX-License-Identifier: MIT 3 * 4 * Copyright © 2017 Intel Corporation 5 */ 6 7 #include <linux/prime_numbers.h> 8 9 #include "gt/intel_engine_pm.h" 10 #include "gt/intel_gpu_commands.h" 11 #include "gt/intel_gt.h" 12 #include "gt/intel_gt_pm.h" 13 #include "gt/intel_ring.h" 14 15 #include "i915_selftest.h" 16 #include "selftests/i915_random.h" 17 18 struct context { 19 struct drm_i915_gem_object *obj; 20 struct intel_engine_cs *engine; 21 }; 22 23 static int cpu_set(struct context *ctx, unsigned long offset, u32 v) 24 { 25 unsigned int needs_clflush; 26 struct page *page; 27 void *map; 28 u32 *cpu; 29 int err; 30 31 i915_gem_object_lock(ctx->obj, NULL); 32 err = i915_gem_object_prepare_write(ctx->obj, &needs_clflush); 33 if (err) 34 goto out; 35 36 page = i915_gem_object_get_page(ctx->obj, offset >> PAGE_SHIFT); 37 map = kmap_atomic(page); 38 cpu = map + offset_in_page(offset); 39 40 if (needs_clflush & CLFLUSH_BEFORE) 41 drm_clflush_virt_range(cpu, sizeof(*cpu)); 42 43 *cpu = v; 44 45 if (needs_clflush & CLFLUSH_AFTER) 46 drm_clflush_virt_range(cpu, sizeof(*cpu)); 47 48 kunmap_atomic(map); 49 i915_gem_object_finish_access(ctx->obj); 50 51 out: 52 i915_gem_object_unlock(ctx->obj); 53 return err; 54 } 55 56 static int cpu_get(struct context *ctx, unsigned long offset, u32 *v) 57 { 58 unsigned int needs_clflush; 59 struct page *page; 60 void *map; 61 u32 *cpu; 62 int err; 63 64 i915_gem_object_lock(ctx->obj, NULL); 65 err = i915_gem_object_prepare_read(ctx->obj, &needs_clflush); 66 if (err) 67 goto out; 68 69 page = i915_gem_object_get_page(ctx->obj, offset >> PAGE_SHIFT); 70 map = kmap_atomic(page); 71 cpu = map + offset_in_page(offset); 72 73 if (needs_clflush & CLFLUSH_BEFORE) 74 drm_clflush_virt_range(cpu, sizeof(*cpu)); 75 76 *v = *cpu; 77 78 kunmap_atomic(map); 79 i915_gem_object_finish_access(ctx->obj); 80 81 out: 82 i915_gem_object_unlock(ctx->obj); 83 return err; 84 } 85 86 static int gtt_set(struct context *ctx, unsigned long offset, u32 v) 87 { 88 struct i915_vma *vma; 89 u32 __iomem *map; 90 int err = 0; 91 92 i915_gem_object_lock(ctx->obj, NULL); 93 err = i915_gem_object_set_to_gtt_domain(ctx->obj, true); 94 i915_gem_object_unlock(ctx->obj); 95 if (err) 96 return err; 97 98 vma = i915_gem_object_ggtt_pin(ctx->obj, NULL, 0, 0, PIN_MAPPABLE); 99 if (IS_ERR(vma)) 100 return PTR_ERR(vma); 101 102 intel_gt_pm_get(vma->vm->gt); 103 104 map = i915_vma_pin_iomap(vma); 105 i915_vma_unpin(vma); 106 if (IS_ERR(map)) { 107 err = PTR_ERR(map); 108 goto out_rpm; 109 } 110 111 iowrite32(v, &map[offset / sizeof(*map)]); 112 i915_vma_unpin_iomap(vma); 113 114 out_rpm: 115 intel_gt_pm_put(vma->vm->gt); 116 return err; 117 } 118 119 static int gtt_get(struct context *ctx, unsigned long offset, u32 *v) 120 { 121 struct i915_vma *vma; 122 u32 __iomem *map; 123 int err = 0; 124 125 i915_gem_object_lock(ctx->obj, NULL); 126 err = i915_gem_object_set_to_gtt_domain(ctx->obj, false); 127 i915_gem_object_unlock(ctx->obj); 128 if (err) 129 return err; 130 131 vma = i915_gem_object_ggtt_pin(ctx->obj, NULL, 0, 0, PIN_MAPPABLE); 132 if (IS_ERR(vma)) 133 return PTR_ERR(vma); 134 135 intel_gt_pm_get(vma->vm->gt); 136 137 map = i915_vma_pin_iomap(vma); 138 i915_vma_unpin(vma); 139 if (IS_ERR(map)) { 140 err = PTR_ERR(map); 141 goto out_rpm; 142 } 143 144 *v = ioread32(&map[offset / sizeof(*map)]); 145 i915_vma_unpin_iomap(vma); 146 147 out_rpm: 148 intel_gt_pm_put(vma->vm->gt); 149 return err; 150 } 151 152 static int wc_set(struct context *ctx, unsigned long offset, u32 v) 153 { 154 u32 *map; 155 int err; 156 157 i915_gem_object_lock(ctx->obj, NULL); 158 err = i915_gem_object_set_to_wc_domain(ctx->obj, true); 159 i915_gem_object_unlock(ctx->obj); 160 if (err) 161 return err; 162 163 map = i915_gem_object_pin_map_unlocked(ctx->obj, I915_MAP_WC); 164 if (IS_ERR(map)) 165 return PTR_ERR(map); 166 167 map[offset / sizeof(*map)] = v; 168 169 __i915_gem_object_flush_map(ctx->obj, offset, sizeof(*map)); 170 i915_gem_object_unpin_map(ctx->obj); 171 172 return 0; 173 } 174 175 static int wc_get(struct context *ctx, unsigned long offset, u32 *v) 176 { 177 u32 *map; 178 int err; 179 180 i915_gem_object_lock(ctx->obj, NULL); 181 err = i915_gem_object_set_to_wc_domain(ctx->obj, false); 182 i915_gem_object_unlock(ctx->obj); 183 if (err) 184 return err; 185 186 map = i915_gem_object_pin_map_unlocked(ctx->obj, I915_MAP_WC); 187 if (IS_ERR(map)) 188 return PTR_ERR(map); 189 190 *v = map[offset / sizeof(*map)]; 191 i915_gem_object_unpin_map(ctx->obj); 192 193 return 0; 194 } 195 196 static int gpu_set(struct context *ctx, unsigned long offset, u32 v) 197 { 198 struct i915_request *rq; 199 struct i915_vma *vma; 200 u32 *cs; 201 int err; 202 203 vma = i915_gem_object_ggtt_pin(ctx->obj, NULL, 0, 0, 0); 204 if (IS_ERR(vma)) 205 return PTR_ERR(vma); 206 207 i915_gem_object_lock(ctx->obj, NULL); 208 err = i915_gem_object_set_to_gtt_domain(ctx->obj, true); 209 if (err) 210 goto out_unlock; 211 212 rq = intel_engine_create_kernel_request(ctx->engine); 213 if (IS_ERR(rq)) { 214 err = PTR_ERR(rq); 215 goto out_unpin; 216 } 217 218 cs = intel_ring_begin(rq, 4); 219 if (IS_ERR(cs)) { 220 err = PTR_ERR(cs); 221 goto out_rq; 222 } 223 224 if (GRAPHICS_VER(ctx->engine->i915) >= 8) { 225 *cs++ = MI_STORE_DWORD_IMM_GEN4 | 1 << 22; 226 *cs++ = lower_32_bits(i915_ggtt_offset(vma) + offset); 227 *cs++ = upper_32_bits(i915_ggtt_offset(vma) + offset); 228 *cs++ = v; 229 } else if (GRAPHICS_VER(ctx->engine->i915) >= 4) { 230 *cs++ = MI_STORE_DWORD_IMM_GEN4 | MI_USE_GGTT; 231 *cs++ = 0; 232 *cs++ = i915_ggtt_offset(vma) + offset; 233 *cs++ = v; 234 } else { 235 *cs++ = MI_STORE_DWORD_IMM | MI_MEM_VIRTUAL; 236 *cs++ = i915_ggtt_offset(vma) + offset; 237 *cs++ = v; 238 *cs++ = MI_NOOP; 239 } 240 intel_ring_advance(rq, cs); 241 242 err = i915_request_await_object(rq, vma->obj, true); 243 if (err == 0) 244 err = i915_vma_move_to_active(vma, rq, EXEC_OBJECT_WRITE); 245 246 out_rq: 247 i915_request_add(rq); 248 out_unpin: 249 i915_vma_unpin(vma); 250 out_unlock: 251 i915_gem_object_unlock(ctx->obj); 252 253 return err; 254 } 255 256 static bool always_valid(struct context *ctx) 257 { 258 return true; 259 } 260 261 static bool needs_fence_registers(struct context *ctx) 262 { 263 struct intel_gt *gt = ctx->engine->gt; 264 265 if (intel_gt_is_wedged(gt)) 266 return false; 267 268 return gt->ggtt->num_fences; 269 } 270 271 static bool needs_mi_store_dword(struct context *ctx) 272 { 273 if (intel_gt_is_wedged(ctx->engine->gt)) 274 return false; 275 276 return intel_engine_can_store_dword(ctx->engine); 277 } 278 279 static const struct igt_coherency_mode { 280 const char *name; 281 int (*set)(struct context *ctx, unsigned long offset, u32 v); 282 int (*get)(struct context *ctx, unsigned long offset, u32 *v); 283 bool (*valid)(struct context *ctx); 284 } igt_coherency_mode[] = { 285 { "cpu", cpu_set, cpu_get, always_valid }, 286 { "gtt", gtt_set, gtt_get, needs_fence_registers }, 287 { "wc", wc_set, wc_get, always_valid }, 288 { "gpu", gpu_set, NULL, needs_mi_store_dword }, 289 { }, 290 }; 291 292 static struct intel_engine_cs * 293 random_engine(struct drm_i915_private *i915, struct rnd_state *prng) 294 { 295 struct intel_engine_cs *engine; 296 unsigned int count; 297 298 count = 0; 299 for_each_uabi_engine(engine, i915) 300 count++; 301 302 count = i915_prandom_u32_max_state(count, prng); 303 for_each_uabi_engine(engine, i915) 304 if (count-- == 0) 305 return engine; 306 307 return NULL; 308 } 309 310 static int igt_gem_coherency(void *arg) 311 { 312 const unsigned int ncachelines = PAGE_SIZE/64; 313 struct drm_i915_private *i915 = arg; 314 const struct igt_coherency_mode *read, *write, *over; 315 unsigned long count, n; 316 u32 *offsets, *values; 317 I915_RND_STATE(prng); 318 struct context ctx; 319 int err = 0; 320 321 /* 322 * We repeatedly write, overwrite and read from a sequence of 323 * cachelines in order to try and detect incoherency (unflushed writes 324 * from either the CPU or GPU). Each setter/getter uses our cache 325 * domain API which should prevent incoherency. 326 */ 327 328 offsets = kmalloc_array(ncachelines, 2*sizeof(u32), GFP_KERNEL); 329 if (!offsets) 330 return -ENOMEM; 331 for (count = 0; count < ncachelines; count++) 332 offsets[count] = count * 64 + 4 * (count % 16); 333 334 values = offsets + ncachelines; 335 336 ctx.engine = random_engine(i915, &prng); 337 if (!ctx.engine) { 338 err = -ENODEV; 339 goto out_free; 340 } 341 pr_info("%s: using %s\n", __func__, ctx.engine->name); 342 intel_engine_pm_get(ctx.engine); 343 344 for (over = igt_coherency_mode; over->name; over++) { 345 if (!over->set) 346 continue; 347 348 if (!over->valid(&ctx)) 349 continue; 350 351 for (write = igt_coherency_mode; write->name; write++) { 352 if (!write->set) 353 continue; 354 355 if (!write->valid(&ctx)) 356 continue; 357 358 for (read = igt_coherency_mode; read->name; read++) { 359 if (!read->get) 360 continue; 361 362 if (!read->valid(&ctx)) 363 continue; 364 365 for_each_prime_number_from(count, 1, ncachelines) { 366 ctx.obj = i915_gem_object_create_internal(i915, PAGE_SIZE); 367 if (IS_ERR(ctx.obj)) { 368 err = PTR_ERR(ctx.obj); 369 goto out_pm; 370 } 371 372 i915_random_reorder(offsets, ncachelines, &prng); 373 for (n = 0; n < count; n++) 374 values[n] = prandom_u32_state(&prng); 375 376 for (n = 0; n < count; n++) { 377 err = over->set(&ctx, offsets[n], ~values[n]); 378 if (err) { 379 pr_err("Failed to set stale value[%ld/%ld] in object using %s, err=%d\n", 380 n, count, over->name, err); 381 goto put_object; 382 } 383 } 384 385 for (n = 0; n < count; n++) { 386 err = write->set(&ctx, offsets[n], values[n]); 387 if (err) { 388 pr_err("Failed to set value[%ld/%ld] in object using %s, err=%d\n", 389 n, count, write->name, err); 390 goto put_object; 391 } 392 } 393 394 for (n = 0; n < count; n++) { 395 u32 found; 396 397 err = read->get(&ctx, offsets[n], &found); 398 if (err) { 399 pr_err("Failed to get value[%ld/%ld] in object using %s, err=%d\n", 400 n, count, read->name, err); 401 goto put_object; 402 } 403 404 if (found != values[n]) { 405 pr_err("Value[%ld/%ld] mismatch, (overwrite with %s) wrote [%s] %x read [%s] %x (inverse %x), at offset %x\n", 406 n, count, over->name, 407 write->name, values[n], 408 read->name, found, 409 ~values[n], offsets[n]); 410 err = -EINVAL; 411 goto put_object; 412 } 413 } 414 415 i915_gem_object_put(ctx.obj); 416 } 417 } 418 } 419 } 420 out_pm: 421 intel_engine_pm_put(ctx.engine); 422 out_free: 423 kfree(offsets); 424 return err; 425 426 put_object: 427 i915_gem_object_put(ctx.obj); 428 goto out_pm; 429 } 430 431 int i915_gem_coherency_live_selftests(struct drm_i915_private *i915) 432 { 433 static const struct i915_subtest tests[] = { 434 SUBTEST(igt_gem_coherency), 435 }; 436 437 return i915_subtests(tests, i915); 438 } 439