1 // SPDX-License-Identifier: MIT 2 /* 3 * Copyright © 2008-2015 Intel Corporation 4 */ 5 6 #include <linux/highmem.h> 7 8 #include "i915_drv.h" 9 #include "i915_reg.h" 10 #include "i915_scatterlist.h" 11 #include "i915_pvinfo.h" 12 #include "i915_vgpu.h" 13 #include "intel_gt_regs.h" 14 #include "intel_mchbar_regs.h" 15 16 /** 17 * DOC: fence register handling 18 * 19 * Important to avoid confusions: "fences" in the i915 driver are not execution 20 * fences used to track command completion but hardware detiler objects which 21 * wrap a given range of the global GTT. Each platform has only a fairly limited 22 * set of these objects. 23 * 24 * Fences are used to detile GTT memory mappings. They're also connected to the 25 * hardware frontbuffer render tracking and hence interact with frontbuffer 26 * compression. Furthermore on older platforms fences are required for tiled 27 * objects used by the display engine. They can also be used by the render 28 * engine - they're required for blitter commands and are optional for render 29 * commands. But on gen4+ both display (with the exception of fbc) and rendering 30 * have their own tiling state bits and don't need fences. 31 * 32 * Also note that fences only support X and Y tiling and hence can't be used for 33 * the fancier new tiling formats like W, Ys and Yf. 34 * 35 * Finally note that because fences are such a restricted resource they're 36 * dynamically associated with objects. Furthermore fence state is committed to 37 * the hardware lazily to avoid unnecessary stalls on gen2/3. Therefore code must 38 * explicitly call i915_gem_object_get_fence() to synchronize fencing status 39 * for cpu access. Also note that some code wants an unfenced view, for those 40 * cases the fence can be removed forcefully with i915_gem_object_put_fence(). 41 * 42 * Internally these functions will synchronize with userspace access by removing 43 * CPU ptes into GTT mmaps (not the GTT ptes themselves) as needed. 44 */ 45 46 #define pipelined 0 47 48 static struct drm_i915_private *fence_to_i915(struct i915_fence_reg *fence) 49 { 50 return fence->ggtt->vm.i915; 51 } 52 53 static struct intel_uncore *fence_to_uncore(struct i915_fence_reg *fence) 54 { 55 return fence->ggtt->vm.gt->uncore; 56 } 57 58 static void i965_write_fence_reg(struct i915_fence_reg *fence) 59 { 60 i915_reg_t fence_reg_lo, fence_reg_hi; 61 int fence_pitch_shift; 62 u64 val; 63 64 if (GRAPHICS_VER(fence_to_i915(fence)) >= 6) { 65 fence_reg_lo = FENCE_REG_GEN6_LO(fence->id); 66 fence_reg_hi = FENCE_REG_GEN6_HI(fence->id); 67 fence_pitch_shift = GEN6_FENCE_PITCH_SHIFT; 68 69 } else { 70 fence_reg_lo = FENCE_REG_965_LO(fence->id); 71 fence_reg_hi = FENCE_REG_965_HI(fence->id); 72 fence_pitch_shift = I965_FENCE_PITCH_SHIFT; 73 } 74 75 val = 0; 76 if (fence->tiling) { 77 unsigned int stride = fence->stride; 78 79 GEM_BUG_ON(!IS_ALIGNED(stride, 128)); 80 81 val = fence->start + fence->size - I965_FENCE_PAGE; 82 val <<= 32; 83 val |= fence->start; 84 val |= (u64)((stride / 128) - 1) << fence_pitch_shift; 85 if (fence->tiling == I915_TILING_Y) 86 val |= BIT(I965_FENCE_TILING_Y_SHIFT); 87 val |= I965_FENCE_REG_VALID; 88 } 89 90 if (!pipelined) { 91 struct intel_uncore *uncore = fence_to_uncore(fence); 92 93 /* 94 * To w/a incoherency with non-atomic 64-bit register updates, 95 * we split the 64-bit update into two 32-bit writes. In order 96 * for a partial fence not to be evaluated between writes, we 97 * precede the update with write to turn off the fence register, 98 * and only enable the fence as the last step. 99 * 100 * For extra levels of paranoia, we make sure each step lands 101 * before applying the next step. 102 */ 103 intel_uncore_write_fw(uncore, fence_reg_lo, 0); 104 intel_uncore_posting_read_fw(uncore, fence_reg_lo); 105 106 intel_uncore_write_fw(uncore, fence_reg_hi, upper_32_bits(val)); 107 intel_uncore_write_fw(uncore, fence_reg_lo, lower_32_bits(val)); 108 intel_uncore_posting_read_fw(uncore, fence_reg_lo); 109 } 110 } 111 112 static void i915_write_fence_reg(struct i915_fence_reg *fence) 113 { 114 u32 val; 115 116 val = 0; 117 if (fence->tiling) { 118 unsigned int stride = fence->stride; 119 unsigned int tiling = fence->tiling; 120 bool is_y_tiled = tiling == I915_TILING_Y; 121 122 if (is_y_tiled && HAS_128_BYTE_Y_TILING(fence_to_i915(fence))) 123 stride /= 128; 124 else 125 stride /= 512; 126 GEM_BUG_ON(!is_power_of_2(stride)); 127 128 val = fence->start; 129 if (is_y_tiled) 130 val |= BIT(I830_FENCE_TILING_Y_SHIFT); 131 val |= I915_FENCE_SIZE_BITS(fence->size); 132 val |= ilog2(stride) << I830_FENCE_PITCH_SHIFT; 133 134 val |= I830_FENCE_REG_VALID; 135 } 136 137 if (!pipelined) { 138 struct intel_uncore *uncore = fence_to_uncore(fence); 139 i915_reg_t reg = FENCE_REG(fence->id); 140 141 intel_uncore_write_fw(uncore, reg, val); 142 intel_uncore_posting_read_fw(uncore, reg); 143 } 144 } 145 146 static void i830_write_fence_reg(struct i915_fence_reg *fence) 147 { 148 u32 val; 149 150 val = 0; 151 if (fence->tiling) { 152 unsigned int stride = fence->stride; 153 154 val = fence->start; 155 if (fence->tiling == I915_TILING_Y) 156 val |= BIT(I830_FENCE_TILING_Y_SHIFT); 157 val |= I830_FENCE_SIZE_BITS(fence->size); 158 val |= ilog2(stride / 128) << I830_FENCE_PITCH_SHIFT; 159 val |= I830_FENCE_REG_VALID; 160 } 161 162 if (!pipelined) { 163 struct intel_uncore *uncore = fence_to_uncore(fence); 164 i915_reg_t reg = FENCE_REG(fence->id); 165 166 intel_uncore_write_fw(uncore, reg, val); 167 intel_uncore_posting_read_fw(uncore, reg); 168 } 169 } 170 171 static void fence_write(struct i915_fence_reg *fence) 172 { 173 struct drm_i915_private *i915 = fence_to_i915(fence); 174 175 /* 176 * Previous access through the fence register is marshalled by 177 * the mb() inside the fault handlers (i915_gem_release_mmaps) 178 * and explicitly managed for internal users. 179 */ 180 181 if (GRAPHICS_VER(i915) == 2) 182 i830_write_fence_reg(fence); 183 else if (GRAPHICS_VER(i915) == 3) 184 i915_write_fence_reg(fence); 185 else 186 i965_write_fence_reg(fence); 187 188 /* 189 * Access through the fenced region afterwards is 190 * ordered by the posting reads whilst writing the registers. 191 */ 192 } 193 194 static bool gpu_uses_fence_registers(struct i915_fence_reg *fence) 195 { 196 return GRAPHICS_VER(fence_to_i915(fence)) < 4; 197 } 198 199 static int fence_update(struct i915_fence_reg *fence, 200 struct i915_vma *vma) 201 { 202 struct i915_ggtt *ggtt = fence->ggtt; 203 struct intel_uncore *uncore = fence_to_uncore(fence); 204 intel_wakeref_t wakeref; 205 struct i915_vma *old; 206 int ret; 207 208 fence->tiling = 0; 209 if (vma) { 210 GEM_BUG_ON(!i915_gem_object_get_stride(vma->obj) || 211 !i915_gem_object_get_tiling(vma->obj)); 212 213 if (!i915_vma_is_map_and_fenceable(vma)) 214 return -EINVAL; 215 216 if (gpu_uses_fence_registers(fence)) { 217 /* implicit 'unfenced' GPU blits */ 218 ret = i915_vma_sync(vma); 219 if (ret) 220 return ret; 221 } 222 223 fence->start = vma->node.start; 224 fence->size = vma->fence_size; 225 fence->stride = i915_gem_object_get_stride(vma->obj); 226 fence->tiling = i915_gem_object_get_tiling(vma->obj); 227 } 228 WRITE_ONCE(fence->dirty, false); 229 230 old = xchg(&fence->vma, NULL); 231 if (old) { 232 /* XXX Ideally we would move the waiting to outside the mutex */ 233 ret = i915_active_wait(&fence->active); 234 if (ret) { 235 fence->vma = old; 236 return ret; 237 } 238 239 i915_vma_flush_writes(old); 240 241 /* 242 * Ensure that all userspace CPU access is completed before 243 * stealing the fence. 244 */ 245 if (old != vma) { 246 GEM_BUG_ON(old->fence != fence); 247 i915_vma_revoke_mmap(old); 248 old->fence = NULL; 249 } 250 251 list_move(&fence->link, &ggtt->fence_list); 252 } 253 254 /* 255 * We only need to update the register itself if the device is awake. 256 * If the device is currently powered down, we will defer the write 257 * to the runtime resume, see intel_ggtt_restore_fences(). 258 * 259 * This only works for removing the fence register, on acquisition 260 * the caller must hold the rpm wakeref. The fence register must 261 * be cleared before we can use any other fences to ensure that 262 * the new fences do not overlap the elided clears, confusing HW. 263 */ 264 wakeref = intel_runtime_pm_get_if_in_use(uncore->rpm); 265 if (!wakeref) { 266 GEM_BUG_ON(vma); 267 return 0; 268 } 269 270 WRITE_ONCE(fence->vma, vma); 271 fence_write(fence); 272 273 if (vma) { 274 vma->fence = fence; 275 list_move_tail(&fence->link, &ggtt->fence_list); 276 } 277 278 intel_runtime_pm_put(uncore->rpm, wakeref); 279 return 0; 280 } 281 282 /** 283 * i915_vma_revoke_fence - force-remove fence for a VMA 284 * @vma: vma to map linearly (not through a fence reg) 285 * 286 * This function force-removes any fence from the given object, which is useful 287 * if the kernel wants to do untiled GTT access. 288 */ 289 void i915_vma_revoke_fence(struct i915_vma *vma) 290 { 291 struct i915_fence_reg *fence = vma->fence; 292 intel_wakeref_t wakeref; 293 294 lockdep_assert_held(&vma->vm->mutex); 295 if (!fence) 296 return; 297 298 GEM_BUG_ON(fence->vma != vma); 299 GEM_BUG_ON(!i915_active_is_idle(&fence->active)); 300 GEM_BUG_ON(atomic_read(&fence->pin_count)); 301 302 fence->tiling = 0; 303 WRITE_ONCE(fence->vma, NULL); 304 vma->fence = NULL; 305 306 /* 307 * Skip the write to HW if and only if the device is currently 308 * suspended. 309 * 310 * If the driver does not currently hold a wakeref (if_in_use == 0), 311 * the device may currently be runtime suspended, or it may be woken 312 * up before the suspend takes place. If the device is not suspended 313 * (powered down) and we skip clearing the fence register, the HW is 314 * left in an undefined state where we may end up with multiple 315 * registers overlapping. 316 */ 317 with_intel_runtime_pm_if_active(fence_to_uncore(fence)->rpm, wakeref) 318 fence_write(fence); 319 } 320 321 static bool fence_is_active(const struct i915_fence_reg *fence) 322 { 323 return fence->vma && i915_vma_is_active(fence->vma); 324 } 325 326 static struct i915_fence_reg *fence_find(struct i915_ggtt *ggtt) 327 { 328 struct i915_fence_reg *active = NULL; 329 struct i915_fence_reg *fence, *fn; 330 331 list_for_each_entry_safe(fence, fn, &ggtt->fence_list, link) { 332 GEM_BUG_ON(fence->vma && fence->vma->fence != fence); 333 334 if (fence == active) /* now seen this fence twice */ 335 active = ERR_PTR(-EAGAIN); 336 337 /* Prefer idle fences so we do not have to wait on the GPU */ 338 if (active != ERR_PTR(-EAGAIN) && fence_is_active(fence)) { 339 if (!active) 340 active = fence; 341 342 list_move_tail(&fence->link, &ggtt->fence_list); 343 continue; 344 } 345 346 if (atomic_read(&fence->pin_count)) 347 continue; 348 349 return fence; 350 } 351 352 /* Wait for completion of pending flips which consume fences */ 353 if (intel_has_pending_fb_unpin(ggtt->vm.i915)) 354 return ERR_PTR(-EAGAIN); 355 356 return ERR_PTR(-ENOBUFS); 357 } 358 359 int __i915_vma_pin_fence(struct i915_vma *vma) 360 { 361 struct i915_ggtt *ggtt = i915_vm_to_ggtt(vma->vm); 362 struct i915_fence_reg *fence; 363 struct i915_vma *set = i915_gem_object_is_tiled(vma->obj) ? vma : NULL; 364 int err; 365 366 lockdep_assert_held(&vma->vm->mutex); 367 368 /* Just update our place in the LRU if our fence is getting reused. */ 369 if (vma->fence) { 370 fence = vma->fence; 371 GEM_BUG_ON(fence->vma != vma); 372 atomic_inc(&fence->pin_count); 373 if (!fence->dirty) { 374 list_move_tail(&fence->link, &ggtt->fence_list); 375 return 0; 376 } 377 } else if (set) { 378 fence = fence_find(ggtt); 379 if (IS_ERR(fence)) 380 return PTR_ERR(fence); 381 382 GEM_BUG_ON(atomic_read(&fence->pin_count)); 383 atomic_inc(&fence->pin_count); 384 } else { 385 return 0; 386 } 387 388 err = fence_update(fence, set); 389 if (err) 390 goto out_unpin; 391 392 GEM_BUG_ON(fence->vma != set); 393 GEM_BUG_ON(vma->fence != (set ? fence : NULL)); 394 395 if (set) 396 return 0; 397 398 out_unpin: 399 atomic_dec(&fence->pin_count); 400 return err; 401 } 402 403 /** 404 * i915_vma_pin_fence - set up fencing for a vma 405 * @vma: vma to map through a fence reg 406 * 407 * When mapping objects through the GTT, userspace wants to be able to write 408 * to them without having to worry about swizzling if the object is tiled. 409 * This function walks the fence regs looking for a free one for @obj, 410 * stealing one if it can't find any. 411 * 412 * It then sets up the reg based on the object's properties: address, pitch 413 * and tiling format. 414 * 415 * For an untiled surface, this removes any existing fence. 416 * 417 * Returns: 418 * 419 * 0 on success, negative error code on failure. 420 */ 421 int i915_vma_pin_fence(struct i915_vma *vma) 422 { 423 int err; 424 425 if (!vma->fence && !i915_gem_object_is_tiled(vma->obj)) 426 return 0; 427 428 /* 429 * Note that we revoke fences on runtime suspend. Therefore the user 430 * must keep the device awake whilst using the fence. 431 */ 432 assert_rpm_wakelock_held(vma->vm->gt->uncore->rpm); 433 GEM_BUG_ON(!i915_vma_is_ggtt(vma)); 434 435 err = mutex_lock_interruptible(&vma->vm->mutex); 436 if (err) 437 return err; 438 439 err = __i915_vma_pin_fence(vma); 440 mutex_unlock(&vma->vm->mutex); 441 442 return err; 443 } 444 445 /** 446 * i915_reserve_fence - Reserve a fence for vGPU 447 * @ggtt: Global GTT 448 * 449 * This function walks the fence regs looking for a free one and remove 450 * it from the fence_list. It is used to reserve fence for vGPU to use. 451 */ 452 struct i915_fence_reg *i915_reserve_fence(struct i915_ggtt *ggtt) 453 { 454 struct i915_fence_reg *fence; 455 int count; 456 int ret; 457 458 lockdep_assert_held(&ggtt->vm.mutex); 459 460 /* Keep at least one fence available for the display engine. */ 461 count = 0; 462 list_for_each_entry(fence, &ggtt->fence_list, link) 463 count += !atomic_read(&fence->pin_count); 464 if (count <= 1) 465 return ERR_PTR(-ENOSPC); 466 467 fence = fence_find(ggtt); 468 if (IS_ERR(fence)) 469 return fence; 470 471 if (fence->vma) { 472 /* Force-remove fence from VMA */ 473 ret = fence_update(fence, NULL); 474 if (ret) 475 return ERR_PTR(ret); 476 } 477 478 list_del(&fence->link); 479 480 return fence; 481 } 482 483 /** 484 * i915_unreserve_fence - Reclaim a reserved fence 485 * @fence: the fence reg 486 * 487 * This function add a reserved fence register from vGPU to the fence_list. 488 */ 489 void i915_unreserve_fence(struct i915_fence_reg *fence) 490 { 491 struct i915_ggtt *ggtt = fence->ggtt; 492 493 lockdep_assert_held(&ggtt->vm.mutex); 494 495 list_add(&fence->link, &ggtt->fence_list); 496 } 497 498 /** 499 * intel_ggtt_restore_fences - restore fence state 500 * @ggtt: Global GTT 501 * 502 * Restore the hw fence state to match the software tracking again, to be called 503 * after a gpu reset and on resume. Note that on runtime suspend we only cancel 504 * the fences, to be reacquired by the user later. 505 */ 506 void intel_ggtt_restore_fences(struct i915_ggtt *ggtt) 507 { 508 int i; 509 510 for (i = 0; i < ggtt->num_fences; i++) 511 fence_write(&ggtt->fence_regs[i]); 512 } 513 514 /** 515 * DOC: tiling swizzling details 516 * 517 * The idea behind tiling is to increase cache hit rates by rearranging 518 * pixel data so that a group of pixel accesses are in the same cacheline. 519 * Performance improvement from doing this on the back/depth buffer are on 520 * the order of 30%. 521 * 522 * Intel architectures make this somewhat more complicated, though, by 523 * adjustments made to addressing of data when the memory is in interleaved 524 * mode (matched pairs of DIMMS) to improve memory bandwidth. 525 * For interleaved memory, the CPU sends every sequential 64 bytes 526 * to an alternate memory channel so it can get the bandwidth from both. 527 * 528 * The GPU also rearranges its accesses for increased bandwidth to interleaved 529 * memory, and it matches what the CPU does for non-tiled. However, when tiled 530 * it does it a little differently, since one walks addresses not just in the 531 * X direction but also Y. So, along with alternating channels when bit 532 * 6 of the address flips, it also alternates when other bits flip -- Bits 9 533 * (every 512 bytes, an X tile scanline) and 10 (every two X tile scanlines) 534 * are common to both the 915 and 965-class hardware. 535 * 536 * The CPU also sometimes XORs in higher bits as well, to improve 537 * bandwidth doing strided access like we do so frequently in graphics. This 538 * is called "Channel XOR Randomization" in the MCH documentation. The result 539 * is that the CPU is XORing in either bit 11 or bit 17 to bit 6 of its address 540 * decode. 541 * 542 * All of this bit 6 XORing has an effect on our memory management, 543 * as we need to make sure that the 3d driver can correctly address object 544 * contents. 545 * 546 * If we don't have interleaved memory, all tiling is safe and no swizzling is 547 * required. 548 * 549 * When bit 17 is XORed in, we simply refuse to tile at all. Bit 550 * 17 is not just a page offset, so as we page an object out and back in, 551 * individual pages in it will have different bit 17 addresses, resulting in 552 * each 64 bytes being swapped with its neighbor! 553 * 554 * Otherwise, if interleaved, we have to tell the 3d driver what the address 555 * swizzling it needs to do is, since it's writing with the CPU to the pages 556 * (bit 6 and potentially bit 11 XORed in), and the GPU is reading from the 557 * pages (bit 6, 9, and 10 XORed in), resulting in a cumulative bit swizzling 558 * required by the CPU of XORing in bit 6, 9, 10, and potentially 11, in order 559 * to match what the GPU expects. 560 */ 561 562 /** 563 * detect_bit_6_swizzle - detect bit 6 swizzling pattern 564 * @ggtt: Global GGTT 565 * 566 * Detects bit 6 swizzling of address lookup between IGD access and CPU 567 * access through main memory. 568 */ 569 static void detect_bit_6_swizzle(struct i915_ggtt *ggtt) 570 { 571 struct intel_uncore *uncore = ggtt->vm.gt->uncore; 572 struct drm_i915_private *i915 = ggtt->vm.i915; 573 u32 swizzle_x = I915_BIT_6_SWIZZLE_UNKNOWN; 574 u32 swizzle_y = I915_BIT_6_SWIZZLE_UNKNOWN; 575 576 if (GRAPHICS_VER(i915) >= 8 || IS_VALLEYVIEW(i915)) { 577 /* 578 * On BDW+, swizzling is not used. We leave the CPU memory 579 * controller in charge of optimizing memory accesses without 580 * the extra address manipulation GPU side. 581 * 582 * VLV and CHV don't have GPU swizzling. 583 */ 584 swizzle_x = I915_BIT_6_SWIZZLE_NONE; 585 swizzle_y = I915_BIT_6_SWIZZLE_NONE; 586 } else if (GRAPHICS_VER(i915) >= 6) { 587 if (i915->preserve_bios_swizzle) { 588 if (intel_uncore_read(uncore, DISP_ARB_CTL) & 589 DISP_TILE_SURFACE_SWIZZLING) { 590 swizzle_x = I915_BIT_6_SWIZZLE_9_10; 591 swizzle_y = I915_BIT_6_SWIZZLE_9; 592 } else { 593 swizzle_x = I915_BIT_6_SWIZZLE_NONE; 594 swizzle_y = I915_BIT_6_SWIZZLE_NONE; 595 } 596 } else { 597 u32 dimm_c0, dimm_c1; 598 599 dimm_c0 = intel_uncore_read(uncore, MAD_DIMM_C0); 600 dimm_c1 = intel_uncore_read(uncore, MAD_DIMM_C1); 601 dimm_c0 &= MAD_DIMM_A_SIZE_MASK | MAD_DIMM_B_SIZE_MASK; 602 dimm_c1 &= MAD_DIMM_A_SIZE_MASK | MAD_DIMM_B_SIZE_MASK; 603 /* 604 * Enable swizzling when the channels are populated 605 * with identically sized dimms. We don't need to check 606 * the 3rd channel because no cpu with gpu attached 607 * ships in that configuration. Also, swizzling only 608 * makes sense for 2 channels anyway. 609 */ 610 if (dimm_c0 == dimm_c1) { 611 swizzle_x = I915_BIT_6_SWIZZLE_9_10; 612 swizzle_y = I915_BIT_6_SWIZZLE_9; 613 } else { 614 swizzle_x = I915_BIT_6_SWIZZLE_NONE; 615 swizzle_y = I915_BIT_6_SWIZZLE_NONE; 616 } 617 } 618 } else if (GRAPHICS_VER(i915) == 5) { 619 /* 620 * On Ironlake whatever DRAM config, GPU always do 621 * same swizzling setup. 622 */ 623 swizzle_x = I915_BIT_6_SWIZZLE_9_10; 624 swizzle_y = I915_BIT_6_SWIZZLE_9; 625 } else if (GRAPHICS_VER(i915) == 2) { 626 /* 627 * As far as we know, the 865 doesn't have these bit 6 628 * swizzling issues. 629 */ 630 swizzle_x = I915_BIT_6_SWIZZLE_NONE; 631 swizzle_y = I915_BIT_6_SWIZZLE_NONE; 632 } else if (IS_G45(i915) || IS_I965G(i915) || IS_G33(i915)) { 633 /* 634 * The 965, G33, and newer, have a very flexible memory 635 * configuration. It will enable dual-channel mode 636 * (interleaving) on as much memory as it can, and the GPU 637 * will additionally sometimes enable different bit 6 638 * swizzling for tiled objects from the CPU. 639 * 640 * Here's what I found on the G965: 641 * slot fill memory size swizzling 642 * 0A 0B 1A 1B 1-ch 2-ch 643 * 512 0 0 0 512 0 O 644 * 512 0 512 0 16 1008 X 645 * 512 0 0 512 16 1008 X 646 * 0 512 0 512 16 1008 X 647 * 1024 1024 1024 0 2048 1024 O 648 * 649 * We could probably detect this based on either the DRB 650 * matching, which was the case for the swizzling required in 651 * the table above, or from the 1-ch value being less than 652 * the minimum size of a rank. 653 * 654 * Reports indicate that the swizzling actually 655 * varies depending upon page placement inside the 656 * channels, i.e. we see swizzled pages where the 657 * banks of memory are paired and unswizzled on the 658 * uneven portion, so leave that as unknown. 659 */ 660 if (intel_uncore_read16(uncore, C0DRB3_BW) == 661 intel_uncore_read16(uncore, C1DRB3_BW)) { 662 swizzle_x = I915_BIT_6_SWIZZLE_9_10; 663 swizzle_y = I915_BIT_6_SWIZZLE_9; 664 } 665 } else { 666 u32 dcc = intel_uncore_read(uncore, DCC); 667 668 /* 669 * On 9xx chipsets, channel interleave by the CPU is 670 * determined by DCC. For single-channel, neither the CPU 671 * nor the GPU do swizzling. For dual channel interleaved, 672 * the GPU's interleave is bit 9 and 10 for X tiled, and bit 673 * 9 for Y tiled. The CPU's interleave is independent, and 674 * can be based on either bit 11 (haven't seen this yet) or 675 * bit 17 (common). 676 */ 677 switch (dcc & DCC_ADDRESSING_MODE_MASK) { 678 case DCC_ADDRESSING_MODE_SINGLE_CHANNEL: 679 case DCC_ADDRESSING_MODE_DUAL_CHANNEL_ASYMMETRIC: 680 swizzle_x = I915_BIT_6_SWIZZLE_NONE; 681 swizzle_y = I915_BIT_6_SWIZZLE_NONE; 682 break; 683 case DCC_ADDRESSING_MODE_DUAL_CHANNEL_INTERLEAVED: 684 if (dcc & DCC_CHANNEL_XOR_DISABLE) { 685 /* 686 * This is the base swizzling by the GPU for 687 * tiled buffers. 688 */ 689 swizzle_x = I915_BIT_6_SWIZZLE_9_10; 690 swizzle_y = I915_BIT_6_SWIZZLE_9; 691 } else if ((dcc & DCC_CHANNEL_XOR_BIT_17) == 0) { 692 /* Bit 11 swizzling by the CPU in addition. */ 693 swizzle_x = I915_BIT_6_SWIZZLE_9_10_11; 694 swizzle_y = I915_BIT_6_SWIZZLE_9_11; 695 } else { 696 /* Bit 17 swizzling by the CPU in addition. */ 697 swizzle_x = I915_BIT_6_SWIZZLE_9_10_17; 698 swizzle_y = I915_BIT_6_SWIZZLE_9_17; 699 } 700 break; 701 } 702 703 /* check for L-shaped memory aka modified enhanced addressing */ 704 if (GRAPHICS_VER(i915) == 4 && 705 !(intel_uncore_read(uncore, DCC2) & DCC2_MODIFIED_ENHANCED_DISABLE)) { 706 swizzle_x = I915_BIT_6_SWIZZLE_UNKNOWN; 707 swizzle_y = I915_BIT_6_SWIZZLE_UNKNOWN; 708 } 709 710 if (dcc == 0xffffffff) { 711 drm_err(&i915->drm, "Couldn't read from MCHBAR. " 712 "Disabling tiling.\n"); 713 swizzle_x = I915_BIT_6_SWIZZLE_UNKNOWN; 714 swizzle_y = I915_BIT_6_SWIZZLE_UNKNOWN; 715 } 716 } 717 718 if (swizzle_x == I915_BIT_6_SWIZZLE_UNKNOWN || 719 swizzle_y == I915_BIT_6_SWIZZLE_UNKNOWN) { 720 /* 721 * Userspace likes to explode if it sees unknown swizzling, 722 * so lie. We will finish the lie when reporting through 723 * the get-tiling-ioctl by reporting the physical swizzle 724 * mode as unknown instead. 725 * 726 * As we don't strictly know what the swizzling is, it may be 727 * bit17 dependent, and so we need to also prevent the pages 728 * from being moved. 729 */ 730 i915->gem_quirks |= GEM_QUIRK_PIN_SWIZZLED_PAGES; 731 swizzle_x = I915_BIT_6_SWIZZLE_NONE; 732 swizzle_y = I915_BIT_6_SWIZZLE_NONE; 733 } 734 735 to_gt(i915)->ggtt->bit_6_swizzle_x = swizzle_x; 736 to_gt(i915)->ggtt->bit_6_swizzle_y = swizzle_y; 737 } 738 739 /* 740 * Swap every 64 bytes of this page around, to account for it having a new 741 * bit 17 of its physical address and therefore being interpreted differently 742 * by the GPU. 743 */ 744 static void swizzle_page(struct page *page) 745 { 746 char temp[64]; 747 char *vaddr; 748 int i; 749 750 vaddr = kmap(page); 751 752 for (i = 0; i < PAGE_SIZE; i += 128) { 753 memcpy(temp, &vaddr[i], 64); 754 memcpy(&vaddr[i], &vaddr[i + 64], 64); 755 memcpy(&vaddr[i + 64], temp, 64); 756 } 757 758 kunmap(page); 759 } 760 761 /** 762 * i915_gem_object_do_bit_17_swizzle - fixup bit 17 swizzling 763 * @obj: i915 GEM buffer object 764 * @pages: the scattergather list of physical pages 765 * 766 * This function fixes up the swizzling in case any page frame number for this 767 * object has changed in bit 17 since that state has been saved with 768 * i915_gem_object_save_bit_17_swizzle(). 769 * 770 * This is called when pinning backing storage again, since the kernel is free 771 * to move unpinned backing storage around (either by directly moving pages or 772 * by swapping them out and back in again). 773 */ 774 void 775 i915_gem_object_do_bit_17_swizzle(struct drm_i915_gem_object *obj, 776 struct sg_table *pages) 777 { 778 struct sgt_iter sgt_iter; 779 struct page *page; 780 int i; 781 782 if (obj->bit_17 == NULL) 783 return; 784 785 i = 0; 786 for_each_sgt_page(page, sgt_iter, pages) { 787 char new_bit_17 = page_to_phys(page) >> 17; 788 789 if ((new_bit_17 & 0x1) != (test_bit(i, obj->bit_17) != 0)) { 790 swizzle_page(page); 791 set_page_dirty(page); 792 } 793 794 i++; 795 } 796 } 797 798 /** 799 * i915_gem_object_save_bit_17_swizzle - save bit 17 swizzling 800 * @obj: i915 GEM buffer object 801 * @pages: the scattergather list of physical pages 802 * 803 * This function saves the bit 17 of each page frame number so that swizzling 804 * can be fixed up later on with i915_gem_object_do_bit_17_swizzle(). This must 805 * be called before the backing storage can be unpinned. 806 */ 807 void 808 i915_gem_object_save_bit_17_swizzle(struct drm_i915_gem_object *obj, 809 struct sg_table *pages) 810 { 811 const unsigned int page_count = obj->base.size >> PAGE_SHIFT; 812 struct sgt_iter sgt_iter; 813 struct page *page; 814 int i; 815 816 if (obj->bit_17 == NULL) { 817 obj->bit_17 = bitmap_zalloc(page_count, GFP_KERNEL); 818 if (obj->bit_17 == NULL) { 819 drm_err(&to_i915(obj->base.dev)->drm, 820 "Failed to allocate memory for bit 17 record\n"); 821 return; 822 } 823 } 824 825 i = 0; 826 827 for_each_sgt_page(page, sgt_iter, pages) { 828 if (page_to_phys(page) & (1 << 17)) 829 __set_bit(i, obj->bit_17); 830 else 831 __clear_bit(i, obj->bit_17); 832 i++; 833 } 834 } 835 836 void intel_ggtt_init_fences(struct i915_ggtt *ggtt) 837 { 838 struct drm_i915_private *i915 = ggtt->vm.i915; 839 struct intel_uncore *uncore = ggtt->vm.gt->uncore; 840 int num_fences; 841 int i; 842 843 INIT_LIST_HEAD(&ggtt->fence_list); 844 INIT_LIST_HEAD(&ggtt->userfault_list); 845 846 detect_bit_6_swizzle(ggtt); 847 848 if (!i915_ggtt_has_aperture(ggtt)) 849 num_fences = 0; 850 else if (GRAPHICS_VER(i915) >= 7 && 851 !(IS_VALLEYVIEW(i915) || IS_CHERRYVIEW(i915))) 852 num_fences = 32; 853 else if (GRAPHICS_VER(i915) >= 4 || 854 IS_I945G(i915) || IS_I945GM(i915) || 855 IS_G33(i915) || IS_PINEVIEW(i915)) 856 num_fences = 16; 857 else 858 num_fences = 8; 859 860 if (intel_vgpu_active(i915)) 861 num_fences = intel_uncore_read(uncore, 862 vgtif_reg(avail_rs.fence_num)); 863 ggtt->fence_regs = kcalloc(num_fences, 864 sizeof(*ggtt->fence_regs), 865 GFP_KERNEL); 866 if (!ggtt->fence_regs) 867 num_fences = 0; 868 869 /* Initialize fence registers to zero */ 870 for (i = 0; i < num_fences; i++) { 871 struct i915_fence_reg *fence = &ggtt->fence_regs[i]; 872 873 i915_active_init(&fence->active, NULL, NULL, 0); 874 fence->ggtt = ggtt; 875 fence->id = i; 876 list_add_tail(&fence->link, &ggtt->fence_list); 877 } 878 ggtt->num_fences = num_fences; 879 880 intel_ggtt_restore_fences(ggtt); 881 } 882 883 void intel_ggtt_fini_fences(struct i915_ggtt *ggtt) 884 { 885 int i; 886 887 for (i = 0; i < ggtt->num_fences; i++) { 888 struct i915_fence_reg *fence = &ggtt->fence_regs[i]; 889 890 i915_active_fini(&fence->active); 891 } 892 893 kfree(ggtt->fence_regs); 894 } 895 896 void intel_gt_init_swizzling(struct intel_gt *gt) 897 { 898 struct drm_i915_private *i915 = gt->i915; 899 struct intel_uncore *uncore = gt->uncore; 900 901 if (GRAPHICS_VER(i915) < 5 || 902 to_gt(i915)->ggtt->bit_6_swizzle_x == I915_BIT_6_SWIZZLE_NONE) 903 return; 904 905 intel_uncore_rmw(uncore, DISP_ARB_CTL, 0, DISP_TILE_SURFACE_SWIZZLING); 906 907 if (GRAPHICS_VER(i915) == 5) 908 return; 909 910 intel_uncore_rmw(uncore, TILECTL, 0, TILECTL_SWZCTL); 911 912 if (GRAPHICS_VER(i915) == 6) 913 intel_uncore_write(uncore, 914 ARB_MODE, 915 _MASKED_BIT_ENABLE(ARB_MODE_SWIZZLE_SNB)); 916 else if (GRAPHICS_VER(i915) == 7) 917 intel_uncore_write(uncore, 918 ARB_MODE, 919 _MASKED_BIT_ENABLE(ARB_MODE_SWIZZLE_IVB)); 920 else if (GRAPHICS_VER(i915) == 8) 921 intel_uncore_write(uncore, 922 GAMTARBMODE, 923 _MASKED_BIT_ENABLE(ARB_MODE_SWIZZLE_BDW)); 924 else 925 MISSING_CASE(GRAPHICS_VER(i915)); 926 } 927