1 // SPDX-License-Identifier: MIT 2 /* 3 * Copyright © 2020 Intel Corporation 4 */ 5 6 #include <linux/log2.h> 7 8 #include "gem/i915_gem_internal.h" 9 10 #include "gen6_ppgtt.h" 11 #include "i915_scatterlist.h" 12 #include "i915_trace.h" 13 #include "i915_vgpu.h" 14 #include "intel_gt_regs.h" 15 #include "intel_engine_regs.h" 16 #include "intel_gt.h" 17 18 /* Write pde (index) from the page directory @pd to the page table @pt */ 19 static void gen6_write_pde(const struct gen6_ppgtt *ppgtt, 20 const unsigned int pde, 21 const struct i915_page_table *pt) 22 { 23 dma_addr_t addr = pt ? px_dma(pt) : px_dma(ppgtt->base.vm.scratch[1]); 24 25 /* Caller needs to make sure the write completes if necessary */ 26 iowrite32(GEN6_PDE_ADDR_ENCODE(addr) | GEN6_PDE_VALID, 27 ppgtt->pd_addr + pde); 28 } 29 30 void gen7_ppgtt_enable(struct intel_gt *gt) 31 { 32 struct drm_i915_private *i915 = gt->i915; 33 struct intel_uncore *uncore = gt->uncore; 34 u32 ecochk; 35 36 intel_uncore_rmw(uncore, GAC_ECO_BITS, 0, ECOBITS_PPGTT_CACHE64B); 37 38 ecochk = intel_uncore_read(uncore, GAM_ECOCHK); 39 if (IS_HASWELL(i915)) { 40 ecochk |= ECOCHK_PPGTT_WB_HSW; 41 } else { 42 ecochk |= ECOCHK_PPGTT_LLC_IVB; 43 ecochk &= ~ECOCHK_PPGTT_GFDT_IVB; 44 } 45 intel_uncore_write(uncore, GAM_ECOCHK, ecochk); 46 } 47 48 void gen6_ppgtt_enable(struct intel_gt *gt) 49 { 50 struct intel_uncore *uncore = gt->uncore; 51 52 intel_uncore_rmw(uncore, 53 GAC_ECO_BITS, 54 0, 55 ECOBITS_SNB_BIT | ECOBITS_PPGTT_CACHE64B); 56 57 intel_uncore_rmw(uncore, 58 GAB_CTL, 59 0, 60 GAB_CTL_CONT_AFTER_PAGEFAULT); 61 62 intel_uncore_rmw(uncore, 63 GAM_ECOCHK, 64 0, 65 ECOCHK_SNB_BIT | ECOCHK_PPGTT_CACHE64B); 66 67 if (HAS_PPGTT(uncore->i915)) /* may be disabled for VT-d */ 68 intel_uncore_write(uncore, 69 GFX_MODE, 70 _MASKED_BIT_ENABLE(GFX_PPGTT_ENABLE)); 71 } 72 73 /* PPGTT support for Sandybdrige/Gen6 and later */ 74 static void gen6_ppgtt_clear_range(struct i915_address_space *vm, 75 u64 start, u64 length) 76 { 77 struct gen6_ppgtt * const ppgtt = to_gen6_ppgtt(i915_vm_to_ppgtt(vm)); 78 const unsigned int first_entry = start / I915_GTT_PAGE_SIZE; 79 const gen6_pte_t scratch_pte = vm->scratch[0]->encode; 80 unsigned int pde = first_entry / GEN6_PTES; 81 unsigned int pte = first_entry % GEN6_PTES; 82 unsigned int num_entries = length / I915_GTT_PAGE_SIZE; 83 84 while (num_entries) { 85 struct i915_page_table * const pt = 86 i915_pt_entry(ppgtt->base.pd, pde++); 87 const unsigned int count = min(num_entries, GEN6_PTES - pte); 88 gen6_pte_t *vaddr; 89 90 num_entries -= count; 91 92 GEM_BUG_ON(count > atomic_read(&pt->used)); 93 if (!atomic_sub_return(count, &pt->used)) 94 ppgtt->scan_for_unused_pt = true; 95 96 /* 97 * Note that the hw doesn't support removing PDE on the fly 98 * (they are cached inside the context with no means to 99 * invalidate the cache), so we can only reset the PTE 100 * entries back to scratch. 101 */ 102 103 vaddr = px_vaddr(pt); 104 memset32(vaddr + pte, scratch_pte, count); 105 106 pte = 0; 107 } 108 } 109 110 static void gen6_ppgtt_insert_entries(struct i915_address_space *vm, 111 struct i915_vma_resource *vma_res, 112 enum i915_cache_level cache_level, 113 u32 flags) 114 { 115 struct i915_ppgtt *ppgtt = i915_vm_to_ppgtt(vm); 116 struct i915_page_directory * const pd = ppgtt->pd; 117 unsigned int first_entry = vma_res->start / I915_GTT_PAGE_SIZE; 118 unsigned int act_pt = first_entry / GEN6_PTES; 119 unsigned int act_pte = first_entry % GEN6_PTES; 120 const u32 pte_encode = vm->pte_encode(0, cache_level, flags); 121 struct sgt_dma iter = sgt_dma(vma_res); 122 gen6_pte_t *vaddr; 123 124 GEM_BUG_ON(!pd->entry[act_pt]); 125 126 vaddr = px_vaddr(i915_pt_entry(pd, act_pt)); 127 do { 128 GEM_BUG_ON(sg_dma_len(iter.sg) < I915_GTT_PAGE_SIZE); 129 vaddr[act_pte] = pte_encode | GEN6_PTE_ADDR_ENCODE(iter.dma); 130 131 iter.dma += I915_GTT_PAGE_SIZE; 132 if (iter.dma == iter.max) { 133 iter.sg = __sg_next(iter.sg); 134 if (!iter.sg || sg_dma_len(iter.sg) == 0) 135 break; 136 137 iter.dma = sg_dma_address(iter.sg); 138 iter.max = iter.dma + sg_dma_len(iter.sg); 139 } 140 141 if (++act_pte == GEN6_PTES) { 142 vaddr = px_vaddr(i915_pt_entry(pd, ++act_pt)); 143 act_pte = 0; 144 } 145 } while (1); 146 147 vma_res->page_sizes_gtt = I915_GTT_PAGE_SIZE; 148 } 149 150 static void gen6_flush_pd(struct gen6_ppgtt *ppgtt, u64 start, u64 end) 151 { 152 struct i915_page_directory * const pd = ppgtt->base.pd; 153 struct i915_page_table *pt; 154 unsigned int pde; 155 156 start = round_down(start, SZ_64K); 157 end = round_up(end, SZ_64K) - start; 158 159 mutex_lock(&ppgtt->flush); 160 161 gen6_for_each_pde(pt, pd, start, end, pde) 162 gen6_write_pde(ppgtt, pde, pt); 163 164 mb(); 165 ioread32(ppgtt->pd_addr + pde - 1); 166 gen6_ggtt_invalidate(ppgtt->base.vm.gt->ggtt); 167 mb(); 168 169 mutex_unlock(&ppgtt->flush); 170 } 171 172 static void gen6_alloc_va_range(struct i915_address_space *vm, 173 struct i915_vm_pt_stash *stash, 174 u64 start, u64 length) 175 { 176 struct gen6_ppgtt *ppgtt = to_gen6_ppgtt(i915_vm_to_ppgtt(vm)); 177 struct i915_page_directory * const pd = ppgtt->base.pd; 178 struct i915_page_table *pt; 179 bool flush = false; 180 u64 from = start; 181 unsigned int pde; 182 183 spin_lock(&pd->lock); 184 gen6_for_each_pde(pt, pd, start, length, pde) { 185 const unsigned int count = gen6_pte_count(start, length); 186 187 if (!pt) { 188 spin_unlock(&pd->lock); 189 190 pt = stash->pt[0]; 191 __i915_gem_object_pin_pages(pt->base); 192 193 fill32_px(pt, vm->scratch[0]->encode); 194 195 spin_lock(&pd->lock); 196 if (!pd->entry[pde]) { 197 stash->pt[0] = pt->stash; 198 atomic_set(&pt->used, 0); 199 pd->entry[pde] = pt; 200 } else { 201 pt = pd->entry[pde]; 202 } 203 204 flush = true; 205 } 206 207 atomic_add(count, &pt->used); 208 } 209 spin_unlock(&pd->lock); 210 211 if (flush && i915_vma_is_bound(ppgtt->vma, I915_VMA_GLOBAL_BIND)) { 212 intel_wakeref_t wakeref; 213 214 with_intel_runtime_pm(&vm->i915->runtime_pm, wakeref) 215 gen6_flush_pd(ppgtt, from, start); 216 } 217 } 218 219 static int gen6_ppgtt_init_scratch(struct gen6_ppgtt *ppgtt) 220 { 221 struct i915_address_space * const vm = &ppgtt->base.vm; 222 int ret; 223 224 ret = setup_scratch_page(vm); 225 if (ret) 226 return ret; 227 228 vm->scratch[0]->encode = 229 vm->pte_encode(px_dma(vm->scratch[0]), 230 I915_CACHE_NONE, PTE_READ_ONLY); 231 232 vm->scratch[1] = vm->alloc_pt_dma(vm, I915_GTT_PAGE_SIZE_4K); 233 if (IS_ERR(vm->scratch[1])) { 234 ret = PTR_ERR(vm->scratch[1]); 235 goto err_scratch0; 236 } 237 238 ret = map_pt_dma(vm, vm->scratch[1]); 239 if (ret) 240 goto err_scratch1; 241 242 fill32_px(vm->scratch[1], vm->scratch[0]->encode); 243 244 return 0; 245 246 err_scratch1: 247 i915_gem_object_put(vm->scratch[1]); 248 err_scratch0: 249 i915_gem_object_put(vm->scratch[0]); 250 return ret; 251 } 252 253 static void gen6_ppgtt_free_pd(struct gen6_ppgtt *ppgtt) 254 { 255 struct i915_page_directory * const pd = ppgtt->base.pd; 256 struct i915_page_table *pt; 257 u32 pde; 258 259 gen6_for_all_pdes(pt, pd, pde) 260 if (pt) 261 free_pt(&ppgtt->base.vm, pt); 262 } 263 264 static void gen6_ppgtt_cleanup(struct i915_address_space *vm) 265 { 266 struct gen6_ppgtt *ppgtt = to_gen6_ppgtt(i915_vm_to_ppgtt(vm)); 267 268 gen6_ppgtt_free_pd(ppgtt); 269 free_scratch(vm); 270 271 mutex_destroy(&ppgtt->flush); 272 273 free_pd(&ppgtt->base.vm, ppgtt->base.pd); 274 } 275 276 static void pd_vma_bind(struct i915_address_space *vm, 277 struct i915_vm_pt_stash *stash, 278 struct i915_vma_resource *vma_res, 279 enum i915_cache_level cache_level, 280 u32 unused) 281 { 282 struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm); 283 struct gen6_ppgtt *ppgtt = vma_res->private; 284 u32 ggtt_offset = vma_res->start / I915_GTT_PAGE_SIZE; 285 286 ppgtt->pp_dir = ggtt_offset * sizeof(gen6_pte_t) << 10; 287 ppgtt->pd_addr = (gen6_pte_t __iomem *)ggtt->gsm + ggtt_offset; 288 289 gen6_flush_pd(ppgtt, 0, ppgtt->base.vm.total); 290 } 291 292 static void pd_vma_unbind(struct i915_address_space *vm, 293 struct i915_vma_resource *vma_res) 294 { 295 struct gen6_ppgtt *ppgtt = vma_res->private; 296 struct i915_page_directory * const pd = ppgtt->base.pd; 297 struct i915_page_table *pt; 298 unsigned int pde; 299 300 if (!ppgtt->scan_for_unused_pt) 301 return; 302 303 /* Free all no longer used page tables */ 304 gen6_for_all_pdes(pt, ppgtt->base.pd, pde) { 305 if (!pt || atomic_read(&pt->used)) 306 continue; 307 308 free_pt(&ppgtt->base.vm, pt); 309 pd->entry[pde] = NULL; 310 } 311 312 ppgtt->scan_for_unused_pt = false; 313 } 314 315 static const struct i915_vma_ops pd_vma_ops = { 316 .bind_vma = pd_vma_bind, 317 .unbind_vma = pd_vma_unbind, 318 }; 319 320 int gen6_ppgtt_pin(struct i915_ppgtt *base, struct i915_gem_ww_ctx *ww) 321 { 322 struct gen6_ppgtt *ppgtt = to_gen6_ppgtt(base); 323 int err; 324 325 GEM_BUG_ON(!kref_read(&ppgtt->base.vm.ref)); 326 327 /* 328 * Workaround the limited maximum vma->pin_count and the aliasing_ppgtt 329 * which will be pinned into every active context. 330 * (When vma->pin_count becomes atomic, I expect we will naturally 331 * need a larger, unpacked, type and kill this redundancy.) 332 */ 333 if (atomic_add_unless(&ppgtt->pin_count, 1, 0)) 334 return 0; 335 336 /* grab the ppgtt resv to pin the object */ 337 err = i915_vm_lock_objects(&ppgtt->base.vm, ww); 338 if (err) 339 return err; 340 341 /* 342 * PPGTT PDEs reside in the GGTT and consists of 512 entries. The 343 * allocator works in address space sizes, so it's multiplied by page 344 * size. We allocate at the top of the GTT to avoid fragmentation. 345 */ 346 if (!atomic_read(&ppgtt->pin_count)) { 347 err = i915_ggtt_pin(ppgtt->vma, ww, GEN6_PD_ALIGN, PIN_HIGH); 348 349 GEM_BUG_ON(ppgtt->vma->fence); 350 clear_bit(I915_VMA_CAN_FENCE_BIT, __i915_vma_flags(ppgtt->vma)); 351 } 352 if (!err) 353 atomic_inc(&ppgtt->pin_count); 354 355 return err; 356 } 357 358 static int pd_dummy_obj_get_pages(struct drm_i915_gem_object *obj) 359 { 360 obj->mm.pages = ZERO_SIZE_PTR; 361 return 0; 362 } 363 364 static void pd_dummy_obj_put_pages(struct drm_i915_gem_object *obj, 365 struct sg_table *pages) 366 { 367 } 368 369 static const struct drm_i915_gem_object_ops pd_dummy_obj_ops = { 370 .name = "pd_dummy_obj", 371 .get_pages = pd_dummy_obj_get_pages, 372 .put_pages = pd_dummy_obj_put_pages, 373 }; 374 375 static struct i915_page_directory * 376 gen6_alloc_top_pd(struct gen6_ppgtt *ppgtt) 377 { 378 struct i915_ggtt * const ggtt = ppgtt->base.vm.gt->ggtt; 379 struct i915_page_directory *pd; 380 int err; 381 382 pd = __alloc_pd(I915_PDES); 383 if (unlikely(!pd)) 384 return ERR_PTR(-ENOMEM); 385 386 pd->pt.base = __i915_gem_object_create_internal(ppgtt->base.vm.gt->i915, 387 &pd_dummy_obj_ops, 388 I915_PDES * SZ_4K); 389 if (IS_ERR(pd->pt.base)) { 390 err = PTR_ERR(pd->pt.base); 391 pd->pt.base = NULL; 392 goto err_pd; 393 } 394 395 pd->pt.base->base.resv = i915_vm_resv_get(&ppgtt->base.vm); 396 pd->pt.base->shares_resv_from = &ppgtt->base.vm; 397 398 ppgtt->vma = i915_vma_instance(pd->pt.base, &ggtt->vm, NULL); 399 if (IS_ERR(ppgtt->vma)) { 400 err = PTR_ERR(ppgtt->vma); 401 ppgtt->vma = NULL; 402 goto err_pd; 403 } 404 405 /* The dummy object we create is special, override ops.. */ 406 ppgtt->vma->ops = &pd_vma_ops; 407 ppgtt->vma->private = ppgtt; 408 return pd; 409 410 err_pd: 411 free_pd(&ppgtt->base.vm, pd); 412 return ERR_PTR(err); 413 } 414 415 void gen6_ppgtt_unpin(struct i915_ppgtt *base) 416 { 417 struct gen6_ppgtt *ppgtt = to_gen6_ppgtt(base); 418 419 GEM_BUG_ON(!atomic_read(&ppgtt->pin_count)); 420 if (atomic_dec_and_test(&ppgtt->pin_count)) 421 i915_vma_unpin(ppgtt->vma); 422 } 423 424 struct i915_ppgtt *gen6_ppgtt_create(struct intel_gt *gt) 425 { 426 struct i915_ggtt * const ggtt = gt->ggtt; 427 struct gen6_ppgtt *ppgtt; 428 int err; 429 430 ppgtt = kzalloc(sizeof(*ppgtt), GFP_KERNEL); 431 if (!ppgtt) 432 return ERR_PTR(-ENOMEM); 433 434 mutex_init(&ppgtt->flush); 435 436 ppgtt_init(&ppgtt->base, gt, 0); 437 ppgtt->base.vm.pd_shift = ilog2(SZ_4K * SZ_4K / sizeof(gen6_pte_t)); 438 ppgtt->base.vm.top = 1; 439 440 ppgtt->base.vm.bind_async_flags = I915_VMA_LOCAL_BIND; 441 ppgtt->base.vm.allocate_va_range = gen6_alloc_va_range; 442 ppgtt->base.vm.clear_range = gen6_ppgtt_clear_range; 443 ppgtt->base.vm.insert_entries = gen6_ppgtt_insert_entries; 444 ppgtt->base.vm.cleanup = gen6_ppgtt_cleanup; 445 446 ppgtt->base.vm.alloc_pt_dma = alloc_pt_dma; 447 ppgtt->base.vm.alloc_scratch_dma = alloc_pt_dma; 448 ppgtt->base.vm.pte_encode = ggtt->vm.pte_encode; 449 450 err = gen6_ppgtt_init_scratch(ppgtt); 451 if (err) 452 goto err_free; 453 454 ppgtt->base.pd = gen6_alloc_top_pd(ppgtt); 455 if (IS_ERR(ppgtt->base.pd)) { 456 err = PTR_ERR(ppgtt->base.pd); 457 goto err_scratch; 458 } 459 460 return &ppgtt->base; 461 462 err_scratch: 463 free_scratch(&ppgtt->base.vm); 464 err_free: 465 kfree(ppgtt); 466 return ERR_PTR(err); 467 } 468