xref: /linux/drivers/gpu/drm/i915/gt/intel_ggtt.c (revision 06bd48b6cd97ef3889b68c8e09014d81dbc463f1)
1 // SPDX-License-Identifier: MIT
2 /*
3  * Copyright © 2020 Intel Corporation
4  */
5 
6 #include <linux/stop_machine.h>
7 
8 #include <asm/set_memory.h>
9 #include <asm/smp.h>
10 
11 #include <drm/i915_drm.h>
12 
13 #include "intel_gt.h"
14 #include "i915_drv.h"
15 #include "i915_scatterlist.h"
16 #include "i915_vgpu.h"
17 
18 #include "intel_gtt.h"
19 
20 static int
21 i915_get_ggtt_vma_pages(struct i915_vma *vma);
22 
23 static void i915_ggtt_color_adjust(const struct drm_mm_node *node,
24 				   unsigned long color,
25 				   u64 *start,
26 				   u64 *end)
27 {
28 	if (i915_node_color_differs(node, color))
29 		*start += I915_GTT_PAGE_SIZE;
30 
31 	/*
32 	 * Also leave a space between the unallocated reserved node after the
33 	 * GTT and any objects within the GTT, i.e. we use the color adjustment
34 	 * to insert a guard page to prevent prefetches crossing over the
35 	 * GTT boundary.
36 	 */
37 	node = list_next_entry(node, node_list);
38 	if (node->color != color)
39 		*end -= I915_GTT_PAGE_SIZE;
40 }
41 
42 static int ggtt_init_hw(struct i915_ggtt *ggtt)
43 {
44 	struct drm_i915_private *i915 = ggtt->vm.i915;
45 
46 	i915_address_space_init(&ggtt->vm, VM_CLASS_GGTT);
47 
48 	ggtt->vm.is_ggtt = true;
49 
50 	/* Only VLV supports read-only GGTT mappings */
51 	ggtt->vm.has_read_only = IS_VALLEYVIEW(i915);
52 
53 	if (!HAS_LLC(i915) && !HAS_PPGTT(i915))
54 		ggtt->vm.mm.color_adjust = i915_ggtt_color_adjust;
55 
56 	if (ggtt->mappable_end) {
57 		if (!io_mapping_init_wc(&ggtt->iomap,
58 					ggtt->gmadr.start,
59 					ggtt->mappable_end)) {
60 			ggtt->vm.cleanup(&ggtt->vm);
61 			return -EIO;
62 		}
63 
64 		ggtt->mtrr = arch_phys_wc_add(ggtt->gmadr.start,
65 					      ggtt->mappable_end);
66 	}
67 
68 	i915_ggtt_init_fences(ggtt);
69 
70 	return 0;
71 }
72 
73 /**
74  * i915_ggtt_init_hw - Initialize GGTT hardware
75  * @i915: i915 device
76  */
77 int i915_ggtt_init_hw(struct drm_i915_private *i915)
78 {
79 	int ret;
80 
81 	stash_init(&i915->mm.wc_stash);
82 
83 	/*
84 	 * Note that we use page colouring to enforce a guard page at the
85 	 * end of the address space. This is required as the CS may prefetch
86 	 * beyond the end of the batch buffer, across the page boundary,
87 	 * and beyond the end of the GTT if we do not provide a guard.
88 	 */
89 	ret = ggtt_init_hw(&i915->ggtt);
90 	if (ret)
91 		return ret;
92 
93 	return 0;
94 }
95 
96 /*
97  * Certain Gen5 chipsets require require idling the GPU before
98  * unmapping anything from the GTT when VT-d is enabled.
99  */
100 static bool needs_idle_maps(struct drm_i915_private *i915)
101 {
102 	/*
103 	 * Query intel_iommu to see if we need the workaround. Presumably that
104 	 * was loaded first.
105 	 */
106 	return IS_GEN(i915, 5) && IS_MOBILE(i915) && intel_vtd_active();
107 }
108 
109 void i915_ggtt_suspend(struct i915_ggtt *ggtt)
110 {
111 	struct i915_vma *vma;
112 
113 	list_for_each_entry(vma, &ggtt->vm.bound_list, vm_link)
114 		i915_vma_wait_for_bind(vma);
115 
116 	ggtt->vm.clear_range(&ggtt->vm, 0, ggtt->vm.total);
117 	ggtt->invalidate(ggtt);
118 
119 	intel_gt_check_and_clear_faults(ggtt->vm.gt);
120 }
121 
122 void gen6_ggtt_invalidate(struct i915_ggtt *ggtt)
123 {
124 	struct intel_uncore *uncore = ggtt->vm.gt->uncore;
125 
126 	spin_lock_irq(&uncore->lock);
127 	intel_uncore_write_fw(uncore, GFX_FLSH_CNTL_GEN6, GFX_FLSH_CNTL_EN);
128 	intel_uncore_read_fw(uncore, GFX_FLSH_CNTL_GEN6);
129 	spin_unlock_irq(&uncore->lock);
130 }
131 
132 static void gen8_ggtt_invalidate(struct i915_ggtt *ggtt)
133 {
134 	struct intel_uncore *uncore = ggtt->vm.gt->uncore;
135 
136 	/*
137 	 * Note that as an uncached mmio write, this will flush the
138 	 * WCB of the writes into the GGTT before it triggers the invalidate.
139 	 */
140 	intel_uncore_write_fw(uncore, GFX_FLSH_CNTL_GEN6, GFX_FLSH_CNTL_EN);
141 }
142 
143 static void guc_ggtt_invalidate(struct i915_ggtt *ggtt)
144 {
145 	struct intel_uncore *uncore = ggtt->vm.gt->uncore;
146 	struct drm_i915_private *i915 = ggtt->vm.i915;
147 
148 	gen8_ggtt_invalidate(ggtt);
149 
150 	if (INTEL_GEN(i915) >= 12)
151 		intel_uncore_write_fw(uncore, GEN12_GUC_TLB_INV_CR,
152 				      GEN12_GUC_TLB_INV_CR_INVALIDATE);
153 	else
154 		intel_uncore_write_fw(uncore, GEN8_GTCR, GEN8_GTCR_INVALIDATE);
155 }
156 
157 static void gmch_ggtt_invalidate(struct i915_ggtt *ggtt)
158 {
159 	intel_gtt_chipset_flush();
160 }
161 
162 static u64 gen8_ggtt_pte_encode(dma_addr_t addr,
163 				enum i915_cache_level level,
164 				u32 flags)
165 {
166 	return addr | _PAGE_PRESENT;
167 }
168 
169 static void gen8_set_pte(void __iomem *addr, gen8_pte_t pte)
170 {
171 	writeq(pte, addr);
172 }
173 
174 static void gen8_ggtt_insert_page(struct i915_address_space *vm,
175 				  dma_addr_t addr,
176 				  u64 offset,
177 				  enum i915_cache_level level,
178 				  u32 unused)
179 {
180 	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
181 	gen8_pte_t __iomem *pte =
182 		(gen8_pte_t __iomem *)ggtt->gsm + offset / I915_GTT_PAGE_SIZE;
183 
184 	gen8_set_pte(pte, gen8_ggtt_pte_encode(addr, level, 0));
185 
186 	ggtt->invalidate(ggtt);
187 }
188 
189 static void gen8_ggtt_insert_entries(struct i915_address_space *vm,
190 				     struct i915_vma *vma,
191 				     enum i915_cache_level level,
192 				     u32 flags)
193 {
194 	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
195 	struct sgt_iter sgt_iter;
196 	gen8_pte_t __iomem *gtt_entries;
197 	const gen8_pte_t pte_encode = gen8_ggtt_pte_encode(0, level, 0);
198 	dma_addr_t addr;
199 
200 	/*
201 	 * Note that we ignore PTE_READ_ONLY here. The caller must be careful
202 	 * not to allow the user to override access to a read only page.
203 	 */
204 
205 	gtt_entries = (gen8_pte_t __iomem *)ggtt->gsm;
206 	gtt_entries += vma->node.start / I915_GTT_PAGE_SIZE;
207 	for_each_sgt_daddr(addr, sgt_iter, vma->pages)
208 		gen8_set_pte(gtt_entries++, pte_encode | addr);
209 
210 	/*
211 	 * We want to flush the TLBs only after we're certain all the PTE
212 	 * updates have finished.
213 	 */
214 	ggtt->invalidate(ggtt);
215 }
216 
217 static void gen6_ggtt_insert_page(struct i915_address_space *vm,
218 				  dma_addr_t addr,
219 				  u64 offset,
220 				  enum i915_cache_level level,
221 				  u32 flags)
222 {
223 	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
224 	gen6_pte_t __iomem *pte =
225 		(gen6_pte_t __iomem *)ggtt->gsm + offset / I915_GTT_PAGE_SIZE;
226 
227 	iowrite32(vm->pte_encode(addr, level, flags), pte);
228 
229 	ggtt->invalidate(ggtt);
230 }
231 
232 /*
233  * Binds an object into the global gtt with the specified cache level.
234  * The object will be accessible to the GPU via commands whose operands
235  * reference offsets within the global GTT as well as accessible by the GPU
236  * through the GMADR mapped BAR (i915->mm.gtt->gtt).
237  */
238 static void gen6_ggtt_insert_entries(struct i915_address_space *vm,
239 				     struct i915_vma *vma,
240 				     enum i915_cache_level level,
241 				     u32 flags)
242 {
243 	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
244 	gen6_pte_t __iomem *entries = (gen6_pte_t __iomem *)ggtt->gsm;
245 	unsigned int i = vma->node.start / I915_GTT_PAGE_SIZE;
246 	struct sgt_iter iter;
247 	dma_addr_t addr;
248 
249 	for_each_sgt_daddr(addr, iter, vma->pages)
250 		iowrite32(vm->pte_encode(addr, level, flags), &entries[i++]);
251 
252 	/*
253 	 * We want to flush the TLBs only after we're certain all the PTE
254 	 * updates have finished.
255 	 */
256 	ggtt->invalidate(ggtt);
257 }
258 
259 static void nop_clear_range(struct i915_address_space *vm,
260 			    u64 start, u64 length)
261 {
262 }
263 
264 static void gen8_ggtt_clear_range(struct i915_address_space *vm,
265 				  u64 start, u64 length)
266 {
267 	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
268 	unsigned int first_entry = start / I915_GTT_PAGE_SIZE;
269 	unsigned int num_entries = length / I915_GTT_PAGE_SIZE;
270 	const gen8_pte_t scratch_pte = vm->scratch[0].encode;
271 	gen8_pte_t __iomem *gtt_base =
272 		(gen8_pte_t __iomem *)ggtt->gsm + first_entry;
273 	const int max_entries = ggtt_total_entries(ggtt) - first_entry;
274 	int i;
275 
276 	if (WARN(num_entries > max_entries,
277 		 "First entry = %d; Num entries = %d (max=%d)\n",
278 		 first_entry, num_entries, max_entries))
279 		num_entries = max_entries;
280 
281 	for (i = 0; i < num_entries; i++)
282 		gen8_set_pte(&gtt_base[i], scratch_pte);
283 }
284 
285 static void bxt_vtd_ggtt_wa(struct i915_address_space *vm)
286 {
287 	/*
288 	 * Make sure the internal GAM fifo has been cleared of all GTT
289 	 * writes before exiting stop_machine(). This guarantees that
290 	 * any aperture accesses waiting to start in another process
291 	 * cannot back up behind the GTT writes causing a hang.
292 	 * The register can be any arbitrary GAM register.
293 	 */
294 	intel_uncore_posting_read_fw(vm->gt->uncore, GFX_FLSH_CNTL_GEN6);
295 }
296 
297 struct insert_page {
298 	struct i915_address_space *vm;
299 	dma_addr_t addr;
300 	u64 offset;
301 	enum i915_cache_level level;
302 };
303 
304 static int bxt_vtd_ggtt_insert_page__cb(void *_arg)
305 {
306 	struct insert_page *arg = _arg;
307 
308 	gen8_ggtt_insert_page(arg->vm, arg->addr, arg->offset, arg->level, 0);
309 	bxt_vtd_ggtt_wa(arg->vm);
310 
311 	return 0;
312 }
313 
314 static void bxt_vtd_ggtt_insert_page__BKL(struct i915_address_space *vm,
315 					  dma_addr_t addr,
316 					  u64 offset,
317 					  enum i915_cache_level level,
318 					  u32 unused)
319 {
320 	struct insert_page arg = { vm, addr, offset, level };
321 
322 	stop_machine(bxt_vtd_ggtt_insert_page__cb, &arg, NULL);
323 }
324 
325 struct insert_entries {
326 	struct i915_address_space *vm;
327 	struct i915_vma *vma;
328 	enum i915_cache_level level;
329 	u32 flags;
330 };
331 
332 static int bxt_vtd_ggtt_insert_entries__cb(void *_arg)
333 {
334 	struct insert_entries *arg = _arg;
335 
336 	gen8_ggtt_insert_entries(arg->vm, arg->vma, arg->level, arg->flags);
337 	bxt_vtd_ggtt_wa(arg->vm);
338 
339 	return 0;
340 }
341 
342 static void bxt_vtd_ggtt_insert_entries__BKL(struct i915_address_space *vm,
343 					     struct i915_vma *vma,
344 					     enum i915_cache_level level,
345 					     u32 flags)
346 {
347 	struct insert_entries arg = { vm, vma, level, flags };
348 
349 	stop_machine(bxt_vtd_ggtt_insert_entries__cb, &arg, NULL);
350 }
351 
352 static void gen6_ggtt_clear_range(struct i915_address_space *vm,
353 				  u64 start, u64 length)
354 {
355 	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
356 	unsigned int first_entry = start / I915_GTT_PAGE_SIZE;
357 	unsigned int num_entries = length / I915_GTT_PAGE_SIZE;
358 	gen6_pte_t scratch_pte, __iomem *gtt_base =
359 		(gen6_pte_t __iomem *)ggtt->gsm + first_entry;
360 	const int max_entries = ggtt_total_entries(ggtt) - first_entry;
361 	int i;
362 
363 	if (WARN(num_entries > max_entries,
364 		 "First entry = %d; Num entries = %d (max=%d)\n",
365 		 first_entry, num_entries, max_entries))
366 		num_entries = max_entries;
367 
368 	scratch_pte = vm->scratch[0].encode;
369 	for (i = 0; i < num_entries; i++)
370 		iowrite32(scratch_pte, &gtt_base[i]);
371 }
372 
373 static void i915_ggtt_insert_page(struct i915_address_space *vm,
374 				  dma_addr_t addr,
375 				  u64 offset,
376 				  enum i915_cache_level cache_level,
377 				  u32 unused)
378 {
379 	unsigned int flags = (cache_level == I915_CACHE_NONE) ?
380 		AGP_USER_MEMORY : AGP_USER_CACHED_MEMORY;
381 
382 	intel_gtt_insert_page(addr, offset >> PAGE_SHIFT, flags);
383 }
384 
385 static void i915_ggtt_insert_entries(struct i915_address_space *vm,
386 				     struct i915_vma *vma,
387 				     enum i915_cache_level cache_level,
388 				     u32 unused)
389 {
390 	unsigned int flags = (cache_level == I915_CACHE_NONE) ?
391 		AGP_USER_MEMORY : AGP_USER_CACHED_MEMORY;
392 
393 	intel_gtt_insert_sg_entries(vma->pages, vma->node.start >> PAGE_SHIFT,
394 				    flags);
395 }
396 
397 static void i915_ggtt_clear_range(struct i915_address_space *vm,
398 				  u64 start, u64 length)
399 {
400 	intel_gtt_clear_range(start >> PAGE_SHIFT, length >> PAGE_SHIFT);
401 }
402 
403 static int ggtt_bind_vma(struct i915_vma *vma,
404 			 enum i915_cache_level cache_level,
405 			 u32 flags)
406 {
407 	struct drm_i915_gem_object *obj = vma->obj;
408 	u32 pte_flags;
409 
410 	/* Applicable to VLV (gen8+ do not support RO in the GGTT) */
411 	pte_flags = 0;
412 	if (i915_gem_object_is_readonly(obj))
413 		pte_flags |= PTE_READ_ONLY;
414 
415 	vma->vm->insert_entries(vma->vm, vma, cache_level, pte_flags);
416 
417 	vma->page_sizes.gtt = I915_GTT_PAGE_SIZE;
418 
419 	/*
420 	 * Without aliasing PPGTT there's no difference between
421 	 * GLOBAL/LOCAL_BIND, it's all the same ptes. Hence unconditionally
422 	 * upgrade to both bound if we bind either to avoid double-binding.
423 	 */
424 	atomic_or(I915_VMA_GLOBAL_BIND | I915_VMA_LOCAL_BIND, &vma->flags);
425 
426 	return 0;
427 }
428 
429 static void ggtt_unbind_vma(struct i915_vma *vma)
430 {
431 	vma->vm->clear_range(vma->vm, vma->node.start, vma->size);
432 }
433 
434 static int ggtt_reserve_guc_top(struct i915_ggtt *ggtt)
435 {
436 	u64 size;
437 	int ret;
438 
439 	if (!intel_uc_uses_guc(&ggtt->vm.gt->uc))
440 		return 0;
441 
442 	GEM_BUG_ON(ggtt->vm.total <= GUC_GGTT_TOP);
443 	size = ggtt->vm.total - GUC_GGTT_TOP;
444 
445 	ret = i915_gem_gtt_reserve(&ggtt->vm, &ggtt->uc_fw, size,
446 				   GUC_GGTT_TOP, I915_COLOR_UNEVICTABLE,
447 				   PIN_NOEVICT);
448 	if (ret)
449 		drm_dbg(&ggtt->vm.i915->drm,
450 			"Failed to reserve top of GGTT for GuC\n");
451 
452 	return ret;
453 }
454 
455 static void ggtt_release_guc_top(struct i915_ggtt *ggtt)
456 {
457 	if (drm_mm_node_allocated(&ggtt->uc_fw))
458 		drm_mm_remove_node(&ggtt->uc_fw);
459 }
460 
461 static void cleanup_init_ggtt(struct i915_ggtt *ggtt)
462 {
463 	ggtt_release_guc_top(ggtt);
464 	if (drm_mm_node_allocated(&ggtt->error_capture))
465 		drm_mm_remove_node(&ggtt->error_capture);
466 	mutex_destroy(&ggtt->error_mutex);
467 }
468 
469 static int init_ggtt(struct i915_ggtt *ggtt)
470 {
471 	/*
472 	 * Let GEM Manage all of the aperture.
473 	 *
474 	 * However, leave one page at the end still bound to the scratch page.
475 	 * There are a number of places where the hardware apparently prefetches
476 	 * past the end of the object, and we've seen multiple hangs with the
477 	 * GPU head pointer stuck in a batchbuffer bound at the last page of the
478 	 * aperture.  One page should be enough to keep any prefetching inside
479 	 * of the aperture.
480 	 */
481 	unsigned long hole_start, hole_end;
482 	struct drm_mm_node *entry;
483 	int ret;
484 
485 	/*
486 	 * GuC requires all resources that we're sharing with it to be placed in
487 	 * non-WOPCM memory. If GuC is not present or not in use we still need a
488 	 * small bias as ring wraparound at offset 0 sometimes hangs. No idea
489 	 * why.
490 	 */
491 	ggtt->pin_bias = max_t(u32, I915_GTT_PAGE_SIZE,
492 			       intel_wopcm_guc_size(&ggtt->vm.i915->wopcm));
493 
494 	ret = intel_vgt_balloon(ggtt);
495 	if (ret)
496 		return ret;
497 
498 	mutex_init(&ggtt->error_mutex);
499 	if (ggtt->mappable_end) {
500 		/* Reserve a mappable slot for our lockless error capture */
501 		ret = drm_mm_insert_node_in_range(&ggtt->vm.mm,
502 						  &ggtt->error_capture,
503 						  PAGE_SIZE, 0,
504 						  I915_COLOR_UNEVICTABLE,
505 						  0, ggtt->mappable_end,
506 						  DRM_MM_INSERT_LOW);
507 		if (ret)
508 			return ret;
509 	}
510 
511 	/*
512 	 * The upper portion of the GuC address space has a sizeable hole
513 	 * (several MB) that is inaccessible by GuC. Reserve this range within
514 	 * GGTT as it can comfortably hold GuC/HuC firmware images.
515 	 */
516 	ret = ggtt_reserve_guc_top(ggtt);
517 	if (ret)
518 		goto err;
519 
520 	/* Clear any non-preallocated blocks */
521 	drm_mm_for_each_hole(entry, &ggtt->vm.mm, hole_start, hole_end) {
522 		drm_dbg_kms(&ggtt->vm.i915->drm,
523 			    "clearing unused GTT space: [%lx, %lx]\n",
524 			    hole_start, hole_end);
525 		ggtt->vm.clear_range(&ggtt->vm, hole_start,
526 				     hole_end - hole_start);
527 	}
528 
529 	/* And finally clear the reserved guard page */
530 	ggtt->vm.clear_range(&ggtt->vm, ggtt->vm.total - PAGE_SIZE, PAGE_SIZE);
531 
532 	return 0;
533 
534 err:
535 	cleanup_init_ggtt(ggtt);
536 	return ret;
537 }
538 
539 static int aliasing_gtt_bind_vma(struct i915_vma *vma,
540 				 enum i915_cache_level cache_level,
541 				 u32 flags)
542 {
543 	u32 pte_flags;
544 	int ret;
545 
546 	/* Currently applicable only to VLV */
547 	pte_flags = 0;
548 	if (i915_gem_object_is_readonly(vma->obj))
549 		pte_flags |= PTE_READ_ONLY;
550 
551 	if (flags & I915_VMA_LOCAL_BIND) {
552 		struct i915_ppgtt *alias = i915_vm_to_ggtt(vma->vm)->alias;
553 
554 		if (flags & I915_VMA_ALLOC) {
555 			ret = alias->vm.allocate_va_range(&alias->vm,
556 							  vma->node.start,
557 							  vma->size);
558 			if (ret)
559 				return ret;
560 
561 			set_bit(I915_VMA_ALLOC_BIT, __i915_vma_flags(vma));
562 		}
563 
564 		GEM_BUG_ON(!test_bit(I915_VMA_ALLOC_BIT,
565 				     __i915_vma_flags(vma)));
566 		alias->vm.insert_entries(&alias->vm, vma,
567 					 cache_level, pte_flags);
568 	}
569 
570 	if (flags & I915_VMA_GLOBAL_BIND)
571 		vma->vm->insert_entries(vma->vm, vma, cache_level, pte_flags);
572 
573 	return 0;
574 }
575 
576 static void aliasing_gtt_unbind_vma(struct i915_vma *vma)
577 {
578 	if (i915_vma_is_bound(vma, I915_VMA_GLOBAL_BIND)) {
579 		struct i915_address_space *vm = vma->vm;
580 
581 		vm->clear_range(vm, vma->node.start, vma->size);
582 	}
583 
584 	if (test_and_clear_bit(I915_VMA_ALLOC_BIT, __i915_vma_flags(vma))) {
585 		struct i915_address_space *vm =
586 			&i915_vm_to_ggtt(vma->vm)->alias->vm;
587 
588 		vm->clear_range(vm, vma->node.start, vma->size);
589 	}
590 }
591 
592 static int init_aliasing_ppgtt(struct i915_ggtt *ggtt)
593 {
594 	struct i915_ppgtt *ppgtt;
595 	int err;
596 
597 	ppgtt = i915_ppgtt_create(ggtt->vm.gt);
598 	if (IS_ERR(ppgtt))
599 		return PTR_ERR(ppgtt);
600 
601 	if (GEM_WARN_ON(ppgtt->vm.total < ggtt->vm.total)) {
602 		err = -ENODEV;
603 		goto err_ppgtt;
604 	}
605 
606 	/*
607 	 * Note we only pre-allocate as far as the end of the global
608 	 * GTT. On 48b / 4-level page-tables, the difference is very,
609 	 * very significant! We have to preallocate as GVT/vgpu does
610 	 * not like the page directory disappearing.
611 	 */
612 	err = ppgtt->vm.allocate_va_range(&ppgtt->vm, 0, ggtt->vm.total);
613 	if (err)
614 		goto err_ppgtt;
615 
616 	ggtt->alias = ppgtt;
617 	ggtt->vm.bind_async_flags |= ppgtt->vm.bind_async_flags;
618 
619 	GEM_BUG_ON(ggtt->vm.vma_ops.bind_vma != ggtt_bind_vma);
620 	ggtt->vm.vma_ops.bind_vma = aliasing_gtt_bind_vma;
621 
622 	GEM_BUG_ON(ggtt->vm.vma_ops.unbind_vma != ggtt_unbind_vma);
623 	ggtt->vm.vma_ops.unbind_vma = aliasing_gtt_unbind_vma;
624 
625 	return 0;
626 
627 err_ppgtt:
628 	i915_vm_put(&ppgtt->vm);
629 	return err;
630 }
631 
632 static void fini_aliasing_ppgtt(struct i915_ggtt *ggtt)
633 {
634 	struct i915_ppgtt *ppgtt;
635 
636 	ppgtt = fetch_and_zero(&ggtt->alias);
637 	if (!ppgtt)
638 		return;
639 
640 	i915_vm_put(&ppgtt->vm);
641 
642 	ggtt->vm.vma_ops.bind_vma   = ggtt_bind_vma;
643 	ggtt->vm.vma_ops.unbind_vma = ggtt_unbind_vma;
644 }
645 
646 int i915_init_ggtt(struct drm_i915_private *i915)
647 {
648 	int ret;
649 
650 	ret = init_ggtt(&i915->ggtt);
651 	if (ret)
652 		return ret;
653 
654 	if (INTEL_PPGTT(i915) == INTEL_PPGTT_ALIASING) {
655 		ret = init_aliasing_ppgtt(&i915->ggtt);
656 		if (ret)
657 			cleanup_init_ggtt(&i915->ggtt);
658 	}
659 
660 	return 0;
661 }
662 
663 static void ggtt_cleanup_hw(struct i915_ggtt *ggtt)
664 {
665 	struct i915_vma *vma, *vn;
666 
667 	atomic_set(&ggtt->vm.open, 0);
668 
669 	rcu_barrier(); /* flush the RCU'ed__i915_vm_release */
670 	flush_workqueue(ggtt->vm.i915->wq);
671 
672 	mutex_lock(&ggtt->vm.mutex);
673 
674 	list_for_each_entry_safe(vma, vn, &ggtt->vm.bound_list, vm_link)
675 		WARN_ON(__i915_vma_unbind(vma));
676 
677 	if (drm_mm_node_allocated(&ggtt->error_capture))
678 		drm_mm_remove_node(&ggtt->error_capture);
679 	mutex_destroy(&ggtt->error_mutex);
680 
681 	ggtt_release_guc_top(ggtt);
682 	intel_vgt_deballoon(ggtt);
683 
684 	ggtt->vm.cleanup(&ggtt->vm);
685 
686 	mutex_unlock(&ggtt->vm.mutex);
687 	i915_address_space_fini(&ggtt->vm);
688 
689 	arch_phys_wc_del(ggtt->mtrr);
690 
691 	if (ggtt->iomap.size)
692 		io_mapping_fini(&ggtt->iomap);
693 }
694 
695 /**
696  * i915_ggtt_driver_release - Clean up GGTT hardware initialization
697  * @i915: i915 device
698  */
699 void i915_ggtt_driver_release(struct drm_i915_private *i915)
700 {
701 	struct pagevec *pvec;
702 
703 	fini_aliasing_ppgtt(&i915->ggtt);
704 
705 	ggtt_cleanup_hw(&i915->ggtt);
706 
707 	pvec = &i915->mm.wc_stash.pvec;
708 	if (pvec->nr) {
709 		set_pages_array_wb(pvec->pages, pvec->nr);
710 		__pagevec_release(pvec);
711 	}
712 }
713 
714 static unsigned int gen6_get_total_gtt_size(u16 snb_gmch_ctl)
715 {
716 	snb_gmch_ctl >>= SNB_GMCH_GGMS_SHIFT;
717 	snb_gmch_ctl &= SNB_GMCH_GGMS_MASK;
718 	return snb_gmch_ctl << 20;
719 }
720 
721 static unsigned int gen8_get_total_gtt_size(u16 bdw_gmch_ctl)
722 {
723 	bdw_gmch_ctl >>= BDW_GMCH_GGMS_SHIFT;
724 	bdw_gmch_ctl &= BDW_GMCH_GGMS_MASK;
725 	if (bdw_gmch_ctl)
726 		bdw_gmch_ctl = 1 << bdw_gmch_ctl;
727 
728 #ifdef CONFIG_X86_32
729 	/* Limit 32b platforms to a 2GB GGTT: 4 << 20 / pte size * I915_GTT_PAGE_SIZE */
730 	if (bdw_gmch_ctl > 4)
731 		bdw_gmch_ctl = 4;
732 #endif
733 
734 	return bdw_gmch_ctl << 20;
735 }
736 
737 static unsigned int chv_get_total_gtt_size(u16 gmch_ctrl)
738 {
739 	gmch_ctrl >>= SNB_GMCH_GGMS_SHIFT;
740 	gmch_ctrl &= SNB_GMCH_GGMS_MASK;
741 
742 	if (gmch_ctrl)
743 		return 1 << (20 + gmch_ctrl);
744 
745 	return 0;
746 }
747 
748 static int ggtt_probe_common(struct i915_ggtt *ggtt, u64 size)
749 {
750 	struct drm_i915_private *i915 = ggtt->vm.i915;
751 	struct pci_dev *pdev = i915->drm.pdev;
752 	phys_addr_t phys_addr;
753 	int ret;
754 
755 	/* For Modern GENs the PTEs and register space are split in the BAR */
756 	phys_addr = pci_resource_start(pdev, 0) + pci_resource_len(pdev, 0) / 2;
757 
758 	/*
759 	 * On BXT+/CNL+ writes larger than 64 bit to the GTT pagetable range
760 	 * will be dropped. For WC mappings in general we have 64 byte burst
761 	 * writes when the WC buffer is flushed, so we can't use it, but have to
762 	 * resort to an uncached mapping. The WC issue is easily caught by the
763 	 * readback check when writing GTT PTE entries.
764 	 */
765 	if (IS_GEN9_LP(i915) || INTEL_GEN(i915) >= 10)
766 		ggtt->gsm = ioremap(phys_addr, size);
767 	else
768 		ggtt->gsm = ioremap_wc(phys_addr, size);
769 	if (!ggtt->gsm) {
770 		DRM_ERROR("Failed to map the ggtt page table\n");
771 		return -ENOMEM;
772 	}
773 
774 	ret = setup_scratch_page(&ggtt->vm, GFP_DMA32);
775 	if (ret) {
776 		DRM_ERROR("Scratch setup failed\n");
777 		/* iounmap will also get called at remove, but meh */
778 		iounmap(ggtt->gsm);
779 		return ret;
780 	}
781 
782 	ggtt->vm.scratch[0].encode =
783 		ggtt->vm.pte_encode(px_dma(&ggtt->vm.scratch[0]),
784 				    I915_CACHE_NONE, 0);
785 
786 	return 0;
787 }
788 
789 int ggtt_set_pages(struct i915_vma *vma)
790 {
791 	int ret;
792 
793 	GEM_BUG_ON(vma->pages);
794 
795 	ret = i915_get_ggtt_vma_pages(vma);
796 	if (ret)
797 		return ret;
798 
799 	vma->page_sizes = vma->obj->mm.page_sizes;
800 
801 	return 0;
802 }
803 
804 static void gen6_gmch_remove(struct i915_address_space *vm)
805 {
806 	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
807 
808 	iounmap(ggtt->gsm);
809 	cleanup_scratch_page(vm);
810 }
811 
812 static struct resource pci_resource(struct pci_dev *pdev, int bar)
813 {
814 	return (struct resource)DEFINE_RES_MEM(pci_resource_start(pdev, bar),
815 					       pci_resource_len(pdev, bar));
816 }
817 
818 static int gen8_gmch_probe(struct i915_ggtt *ggtt)
819 {
820 	struct drm_i915_private *i915 = ggtt->vm.i915;
821 	struct pci_dev *pdev = i915->drm.pdev;
822 	unsigned int size;
823 	u16 snb_gmch_ctl;
824 	int err;
825 
826 	/* TODO: We're not aware of mappable constraints on gen8 yet */
827 	if (!IS_DGFX(i915)) {
828 		ggtt->gmadr = pci_resource(pdev, 2);
829 		ggtt->mappable_end = resource_size(&ggtt->gmadr);
830 	}
831 
832 	err = pci_set_dma_mask(pdev, DMA_BIT_MASK(39));
833 	if (!err)
834 		err = pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(39));
835 	if (err)
836 		DRM_ERROR("Can't set DMA mask/consistent mask (%d)\n", err);
837 
838 	pci_read_config_word(pdev, SNB_GMCH_CTRL, &snb_gmch_ctl);
839 	if (IS_CHERRYVIEW(i915))
840 		size = chv_get_total_gtt_size(snb_gmch_ctl);
841 	else
842 		size = gen8_get_total_gtt_size(snb_gmch_ctl);
843 
844 	ggtt->vm.total = (size / sizeof(gen8_pte_t)) * I915_GTT_PAGE_SIZE;
845 	ggtt->vm.cleanup = gen6_gmch_remove;
846 	ggtt->vm.insert_page = gen8_ggtt_insert_page;
847 	ggtt->vm.clear_range = nop_clear_range;
848 	if (intel_scanout_needs_vtd_wa(i915))
849 		ggtt->vm.clear_range = gen8_ggtt_clear_range;
850 
851 	ggtt->vm.insert_entries = gen8_ggtt_insert_entries;
852 
853 	/* Serialize GTT updates with aperture access on BXT if VT-d is on. */
854 	if (intel_ggtt_update_needs_vtd_wa(i915) ||
855 	    IS_CHERRYVIEW(i915) /* fails with concurrent use/update */) {
856 		ggtt->vm.insert_entries = bxt_vtd_ggtt_insert_entries__BKL;
857 		ggtt->vm.insert_page    = bxt_vtd_ggtt_insert_page__BKL;
858 		ggtt->vm.bind_async_flags =
859 			I915_VMA_GLOBAL_BIND | I915_VMA_LOCAL_BIND;
860 	}
861 
862 	ggtt->invalidate = gen8_ggtt_invalidate;
863 
864 	ggtt->vm.vma_ops.bind_vma    = ggtt_bind_vma;
865 	ggtt->vm.vma_ops.unbind_vma  = ggtt_unbind_vma;
866 	ggtt->vm.vma_ops.set_pages   = ggtt_set_pages;
867 	ggtt->vm.vma_ops.clear_pages = clear_pages;
868 
869 	ggtt->vm.pte_encode = gen8_ggtt_pte_encode;
870 
871 	setup_private_pat(ggtt->vm.gt->uncore);
872 
873 	return ggtt_probe_common(ggtt, size);
874 }
875 
876 static u64 snb_pte_encode(dma_addr_t addr,
877 			  enum i915_cache_level level,
878 			  u32 flags)
879 {
880 	gen6_pte_t pte = GEN6_PTE_ADDR_ENCODE(addr) | GEN6_PTE_VALID;
881 
882 	switch (level) {
883 	case I915_CACHE_L3_LLC:
884 	case I915_CACHE_LLC:
885 		pte |= GEN6_PTE_CACHE_LLC;
886 		break;
887 	case I915_CACHE_NONE:
888 		pte |= GEN6_PTE_UNCACHED;
889 		break;
890 	default:
891 		MISSING_CASE(level);
892 	}
893 
894 	return pte;
895 }
896 
897 static u64 ivb_pte_encode(dma_addr_t addr,
898 			  enum i915_cache_level level,
899 			  u32 flags)
900 {
901 	gen6_pte_t pte = GEN6_PTE_ADDR_ENCODE(addr) | GEN6_PTE_VALID;
902 
903 	switch (level) {
904 	case I915_CACHE_L3_LLC:
905 		pte |= GEN7_PTE_CACHE_L3_LLC;
906 		break;
907 	case I915_CACHE_LLC:
908 		pte |= GEN6_PTE_CACHE_LLC;
909 		break;
910 	case I915_CACHE_NONE:
911 		pte |= GEN6_PTE_UNCACHED;
912 		break;
913 	default:
914 		MISSING_CASE(level);
915 	}
916 
917 	return pte;
918 }
919 
920 static u64 byt_pte_encode(dma_addr_t addr,
921 			  enum i915_cache_level level,
922 			  u32 flags)
923 {
924 	gen6_pte_t pte = GEN6_PTE_ADDR_ENCODE(addr) | GEN6_PTE_VALID;
925 
926 	if (!(flags & PTE_READ_ONLY))
927 		pte |= BYT_PTE_WRITEABLE;
928 
929 	if (level != I915_CACHE_NONE)
930 		pte |= BYT_PTE_SNOOPED_BY_CPU_CACHES;
931 
932 	return pte;
933 }
934 
935 static u64 hsw_pte_encode(dma_addr_t addr,
936 			  enum i915_cache_level level,
937 			  u32 flags)
938 {
939 	gen6_pte_t pte = HSW_PTE_ADDR_ENCODE(addr) | GEN6_PTE_VALID;
940 
941 	if (level != I915_CACHE_NONE)
942 		pte |= HSW_WB_LLC_AGE3;
943 
944 	return pte;
945 }
946 
947 static u64 iris_pte_encode(dma_addr_t addr,
948 			   enum i915_cache_level level,
949 			   u32 flags)
950 {
951 	gen6_pte_t pte = HSW_PTE_ADDR_ENCODE(addr) | GEN6_PTE_VALID;
952 
953 	switch (level) {
954 	case I915_CACHE_NONE:
955 		break;
956 	case I915_CACHE_WT:
957 		pte |= HSW_WT_ELLC_LLC_AGE3;
958 		break;
959 	default:
960 		pte |= HSW_WB_ELLC_LLC_AGE3;
961 		break;
962 	}
963 
964 	return pte;
965 }
966 
967 static int gen6_gmch_probe(struct i915_ggtt *ggtt)
968 {
969 	struct drm_i915_private *i915 = ggtt->vm.i915;
970 	struct pci_dev *pdev = i915->drm.pdev;
971 	unsigned int size;
972 	u16 snb_gmch_ctl;
973 	int err;
974 
975 	ggtt->gmadr = pci_resource(pdev, 2);
976 	ggtt->mappable_end = resource_size(&ggtt->gmadr);
977 
978 	/*
979 	 * 64/512MB is the current min/max we actually know of, but this is
980 	 * just a coarse sanity check.
981 	 */
982 	if (ggtt->mappable_end < (64<<20) || ggtt->mappable_end > (512<<20)) {
983 		DRM_ERROR("Unknown GMADR size (%pa)\n", &ggtt->mappable_end);
984 		return -ENXIO;
985 	}
986 
987 	err = pci_set_dma_mask(pdev, DMA_BIT_MASK(40));
988 	if (!err)
989 		err = pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(40));
990 	if (err)
991 		DRM_ERROR("Can't set DMA mask/consistent mask (%d)\n", err);
992 	pci_read_config_word(pdev, SNB_GMCH_CTRL, &snb_gmch_ctl);
993 
994 	size = gen6_get_total_gtt_size(snb_gmch_ctl);
995 	ggtt->vm.total = (size / sizeof(gen6_pte_t)) * I915_GTT_PAGE_SIZE;
996 
997 	ggtt->vm.clear_range = nop_clear_range;
998 	if (!HAS_FULL_PPGTT(i915) || intel_scanout_needs_vtd_wa(i915))
999 		ggtt->vm.clear_range = gen6_ggtt_clear_range;
1000 	ggtt->vm.insert_page = gen6_ggtt_insert_page;
1001 	ggtt->vm.insert_entries = gen6_ggtt_insert_entries;
1002 	ggtt->vm.cleanup = gen6_gmch_remove;
1003 
1004 	ggtt->invalidate = gen6_ggtt_invalidate;
1005 
1006 	if (HAS_EDRAM(i915))
1007 		ggtt->vm.pte_encode = iris_pte_encode;
1008 	else if (IS_HASWELL(i915))
1009 		ggtt->vm.pte_encode = hsw_pte_encode;
1010 	else if (IS_VALLEYVIEW(i915))
1011 		ggtt->vm.pte_encode = byt_pte_encode;
1012 	else if (INTEL_GEN(i915) >= 7)
1013 		ggtt->vm.pte_encode = ivb_pte_encode;
1014 	else
1015 		ggtt->vm.pte_encode = snb_pte_encode;
1016 
1017 	ggtt->vm.vma_ops.bind_vma    = ggtt_bind_vma;
1018 	ggtt->vm.vma_ops.unbind_vma  = ggtt_unbind_vma;
1019 	ggtt->vm.vma_ops.set_pages   = ggtt_set_pages;
1020 	ggtt->vm.vma_ops.clear_pages = clear_pages;
1021 
1022 	return ggtt_probe_common(ggtt, size);
1023 }
1024 
1025 static void i915_gmch_remove(struct i915_address_space *vm)
1026 {
1027 	intel_gmch_remove();
1028 }
1029 
1030 static int i915_gmch_probe(struct i915_ggtt *ggtt)
1031 {
1032 	struct drm_i915_private *i915 = ggtt->vm.i915;
1033 	phys_addr_t gmadr_base;
1034 	int ret;
1035 
1036 	ret = intel_gmch_probe(i915->bridge_dev, i915->drm.pdev, NULL);
1037 	if (!ret) {
1038 		DRM_ERROR("failed to set up gmch\n");
1039 		return -EIO;
1040 	}
1041 
1042 	intel_gtt_get(&ggtt->vm.total, &gmadr_base, &ggtt->mappable_end);
1043 
1044 	ggtt->gmadr =
1045 		(struct resource)DEFINE_RES_MEM(gmadr_base, ggtt->mappable_end);
1046 
1047 	ggtt->do_idle_maps = needs_idle_maps(i915);
1048 	ggtt->vm.insert_page = i915_ggtt_insert_page;
1049 	ggtt->vm.insert_entries = i915_ggtt_insert_entries;
1050 	ggtt->vm.clear_range = i915_ggtt_clear_range;
1051 	ggtt->vm.cleanup = i915_gmch_remove;
1052 
1053 	ggtt->invalidate = gmch_ggtt_invalidate;
1054 
1055 	ggtt->vm.vma_ops.bind_vma    = ggtt_bind_vma;
1056 	ggtt->vm.vma_ops.unbind_vma  = ggtt_unbind_vma;
1057 	ggtt->vm.vma_ops.set_pages   = ggtt_set_pages;
1058 	ggtt->vm.vma_ops.clear_pages = clear_pages;
1059 
1060 	if (unlikely(ggtt->do_idle_maps))
1061 		dev_notice(i915->drm.dev,
1062 			   "Applying Ironlake quirks for intel_iommu\n");
1063 
1064 	return 0;
1065 }
1066 
1067 static int ggtt_probe_hw(struct i915_ggtt *ggtt, struct intel_gt *gt)
1068 {
1069 	struct drm_i915_private *i915 = gt->i915;
1070 	int ret;
1071 
1072 	ggtt->vm.gt = gt;
1073 	ggtt->vm.i915 = i915;
1074 	ggtt->vm.dma = &i915->drm.pdev->dev;
1075 
1076 	if (INTEL_GEN(i915) <= 5)
1077 		ret = i915_gmch_probe(ggtt);
1078 	else if (INTEL_GEN(i915) < 8)
1079 		ret = gen6_gmch_probe(ggtt);
1080 	else
1081 		ret = gen8_gmch_probe(ggtt);
1082 	if (ret)
1083 		return ret;
1084 
1085 	if ((ggtt->vm.total - 1) >> 32) {
1086 		DRM_ERROR("We never expected a Global GTT with more than 32bits"
1087 			  " of address space! Found %lldM!\n",
1088 			  ggtt->vm.total >> 20);
1089 		ggtt->vm.total = 1ULL << 32;
1090 		ggtt->mappable_end =
1091 			min_t(u64, ggtt->mappable_end, ggtt->vm.total);
1092 	}
1093 
1094 	if (ggtt->mappable_end > ggtt->vm.total) {
1095 		DRM_ERROR("mappable aperture extends past end of GGTT,"
1096 			  " aperture=%pa, total=%llx\n",
1097 			  &ggtt->mappable_end, ggtt->vm.total);
1098 		ggtt->mappable_end = ggtt->vm.total;
1099 	}
1100 
1101 	/* GMADR is the PCI mmio aperture into the global GTT. */
1102 	DRM_DEBUG_DRIVER("GGTT size = %lluM\n", ggtt->vm.total >> 20);
1103 	DRM_DEBUG_DRIVER("GMADR size = %lluM\n", (u64)ggtt->mappable_end >> 20);
1104 	DRM_DEBUG_DRIVER("DSM size = %lluM\n",
1105 			 (u64)resource_size(&intel_graphics_stolen_res) >> 20);
1106 
1107 	return 0;
1108 }
1109 
1110 /**
1111  * i915_ggtt_probe_hw - Probe GGTT hardware location
1112  * @i915: i915 device
1113  */
1114 int i915_ggtt_probe_hw(struct drm_i915_private *i915)
1115 {
1116 	int ret;
1117 
1118 	ret = ggtt_probe_hw(&i915->ggtt, &i915->gt);
1119 	if (ret)
1120 		return ret;
1121 
1122 	if (intel_vtd_active())
1123 		dev_info(i915->drm.dev, "VT-d active for gfx access\n");
1124 
1125 	return 0;
1126 }
1127 
1128 int i915_ggtt_enable_hw(struct drm_i915_private *i915)
1129 {
1130 	if (INTEL_GEN(i915) < 6 && !intel_enable_gtt())
1131 		return -EIO;
1132 
1133 	return 0;
1134 }
1135 
1136 void i915_ggtt_enable_guc(struct i915_ggtt *ggtt)
1137 {
1138 	GEM_BUG_ON(ggtt->invalidate != gen8_ggtt_invalidate);
1139 
1140 	ggtt->invalidate = guc_ggtt_invalidate;
1141 
1142 	ggtt->invalidate(ggtt);
1143 }
1144 
1145 void i915_ggtt_disable_guc(struct i915_ggtt *ggtt)
1146 {
1147 	/* XXX Temporary pardon for error unload */
1148 	if (ggtt->invalidate == gen8_ggtt_invalidate)
1149 		return;
1150 
1151 	/* We should only be called after i915_ggtt_enable_guc() */
1152 	GEM_BUG_ON(ggtt->invalidate != guc_ggtt_invalidate);
1153 
1154 	ggtt->invalidate = gen8_ggtt_invalidate;
1155 
1156 	ggtt->invalidate(ggtt);
1157 }
1158 
1159 void i915_ggtt_resume(struct i915_ggtt *ggtt)
1160 {
1161 	struct i915_vma *vma;
1162 	bool flush = false;
1163 	int open;
1164 
1165 	intel_gt_check_and_clear_faults(ggtt->vm.gt);
1166 
1167 	/* First fill our portion of the GTT with scratch pages */
1168 	ggtt->vm.clear_range(&ggtt->vm, 0, ggtt->vm.total);
1169 
1170 	/* Skip rewriting PTE on VMA unbind. */
1171 	open = atomic_xchg(&ggtt->vm.open, 0);
1172 
1173 	/* clflush objects bound into the GGTT and rebind them. */
1174 	list_for_each_entry(vma, &ggtt->vm.bound_list, vm_link) {
1175 		struct drm_i915_gem_object *obj = vma->obj;
1176 
1177 		if (!i915_vma_is_bound(vma, I915_VMA_GLOBAL_BIND))
1178 			continue;
1179 
1180 		clear_bit(I915_VMA_GLOBAL_BIND_BIT, __i915_vma_flags(vma));
1181 		WARN_ON(i915_vma_bind(vma,
1182 				      obj ? obj->cache_level : 0,
1183 				      PIN_GLOBAL, NULL));
1184 		if (obj) { /* only used during resume => exclusive access */
1185 			flush |= fetch_and_zero(&obj->write_domain);
1186 			obj->read_domains |= I915_GEM_DOMAIN_GTT;
1187 		}
1188 	}
1189 
1190 	atomic_set(&ggtt->vm.open, open);
1191 	ggtt->invalidate(ggtt);
1192 
1193 	if (flush)
1194 		wbinvd_on_all_cpus();
1195 
1196 	if (INTEL_GEN(ggtt->vm.i915) >= 8)
1197 		setup_private_pat(ggtt->vm.gt->uncore);
1198 }
1199 
1200 static struct scatterlist *
1201 rotate_pages(struct drm_i915_gem_object *obj, unsigned int offset,
1202 	     unsigned int width, unsigned int height,
1203 	     unsigned int stride,
1204 	     struct sg_table *st, struct scatterlist *sg)
1205 {
1206 	unsigned int column, row;
1207 	unsigned int src_idx;
1208 
1209 	for (column = 0; column < width; column++) {
1210 		src_idx = stride * (height - 1) + column + offset;
1211 		for (row = 0; row < height; row++) {
1212 			st->nents++;
1213 			/*
1214 			 * We don't need the pages, but need to initialize
1215 			 * the entries so the sg list can be happily traversed.
1216 			 * The only thing we need are DMA addresses.
1217 			 */
1218 			sg_set_page(sg, NULL, I915_GTT_PAGE_SIZE, 0);
1219 			sg_dma_address(sg) =
1220 				i915_gem_object_get_dma_address(obj, src_idx);
1221 			sg_dma_len(sg) = I915_GTT_PAGE_SIZE;
1222 			sg = sg_next(sg);
1223 			src_idx -= stride;
1224 		}
1225 	}
1226 
1227 	return sg;
1228 }
1229 
1230 static noinline struct sg_table *
1231 intel_rotate_pages(struct intel_rotation_info *rot_info,
1232 		   struct drm_i915_gem_object *obj)
1233 {
1234 	unsigned int size = intel_rotation_info_size(rot_info);
1235 	struct drm_i915_private *i915 = to_i915(obj->base.dev);
1236 	struct sg_table *st;
1237 	struct scatterlist *sg;
1238 	int ret = -ENOMEM;
1239 	int i;
1240 
1241 	/* Allocate target SG list. */
1242 	st = kmalloc(sizeof(*st), GFP_KERNEL);
1243 	if (!st)
1244 		goto err_st_alloc;
1245 
1246 	ret = sg_alloc_table(st, size, GFP_KERNEL);
1247 	if (ret)
1248 		goto err_sg_alloc;
1249 
1250 	st->nents = 0;
1251 	sg = st->sgl;
1252 
1253 	for (i = 0 ; i < ARRAY_SIZE(rot_info->plane); i++) {
1254 		sg = rotate_pages(obj, rot_info->plane[i].offset,
1255 				  rot_info->plane[i].width, rot_info->plane[i].height,
1256 				  rot_info->plane[i].stride, st, sg);
1257 	}
1258 
1259 	return st;
1260 
1261 err_sg_alloc:
1262 	kfree(st);
1263 err_st_alloc:
1264 
1265 	drm_dbg(&i915->drm, "Failed to create rotated mapping for object size %zu! (%ux%u tiles, %u pages)\n",
1266 		obj->base.size, rot_info->plane[0].width,
1267 		rot_info->plane[0].height, size);
1268 
1269 	return ERR_PTR(ret);
1270 }
1271 
1272 static struct scatterlist *
1273 remap_pages(struct drm_i915_gem_object *obj, unsigned int offset,
1274 	    unsigned int width, unsigned int height,
1275 	    unsigned int stride,
1276 	    struct sg_table *st, struct scatterlist *sg)
1277 {
1278 	unsigned int row;
1279 
1280 	for (row = 0; row < height; row++) {
1281 		unsigned int left = width * I915_GTT_PAGE_SIZE;
1282 
1283 		while (left) {
1284 			dma_addr_t addr;
1285 			unsigned int length;
1286 
1287 			/*
1288 			 * We don't need the pages, but need to initialize
1289 			 * the entries so the sg list can be happily traversed.
1290 			 * The only thing we need are DMA addresses.
1291 			 */
1292 
1293 			addr = i915_gem_object_get_dma_address_len(obj, offset, &length);
1294 
1295 			length = min(left, length);
1296 
1297 			st->nents++;
1298 
1299 			sg_set_page(sg, NULL, length, 0);
1300 			sg_dma_address(sg) = addr;
1301 			sg_dma_len(sg) = length;
1302 			sg = sg_next(sg);
1303 
1304 			offset += length / I915_GTT_PAGE_SIZE;
1305 			left -= length;
1306 		}
1307 
1308 		offset += stride - width;
1309 	}
1310 
1311 	return sg;
1312 }
1313 
1314 static noinline struct sg_table *
1315 intel_remap_pages(struct intel_remapped_info *rem_info,
1316 		  struct drm_i915_gem_object *obj)
1317 {
1318 	unsigned int size = intel_remapped_info_size(rem_info);
1319 	struct drm_i915_private *i915 = to_i915(obj->base.dev);
1320 	struct sg_table *st;
1321 	struct scatterlist *sg;
1322 	int ret = -ENOMEM;
1323 	int i;
1324 
1325 	/* Allocate target SG list. */
1326 	st = kmalloc(sizeof(*st), GFP_KERNEL);
1327 	if (!st)
1328 		goto err_st_alloc;
1329 
1330 	ret = sg_alloc_table(st, size, GFP_KERNEL);
1331 	if (ret)
1332 		goto err_sg_alloc;
1333 
1334 	st->nents = 0;
1335 	sg = st->sgl;
1336 
1337 	for (i = 0 ; i < ARRAY_SIZE(rem_info->plane); i++) {
1338 		sg = remap_pages(obj, rem_info->plane[i].offset,
1339 				 rem_info->plane[i].width, rem_info->plane[i].height,
1340 				 rem_info->plane[i].stride, st, sg);
1341 	}
1342 
1343 	i915_sg_trim(st);
1344 
1345 	return st;
1346 
1347 err_sg_alloc:
1348 	kfree(st);
1349 err_st_alloc:
1350 
1351 	drm_dbg(&i915->drm, "Failed to create remapped mapping for object size %zu! (%ux%u tiles, %u pages)\n",
1352 		obj->base.size, rem_info->plane[0].width,
1353 		rem_info->plane[0].height, size);
1354 
1355 	return ERR_PTR(ret);
1356 }
1357 
1358 static noinline struct sg_table *
1359 intel_partial_pages(const struct i915_ggtt_view *view,
1360 		    struct drm_i915_gem_object *obj)
1361 {
1362 	struct sg_table *st;
1363 	struct scatterlist *sg, *iter;
1364 	unsigned int count = view->partial.size;
1365 	unsigned int offset;
1366 	int ret = -ENOMEM;
1367 
1368 	st = kmalloc(sizeof(*st), GFP_KERNEL);
1369 	if (!st)
1370 		goto err_st_alloc;
1371 
1372 	ret = sg_alloc_table(st, count, GFP_KERNEL);
1373 	if (ret)
1374 		goto err_sg_alloc;
1375 
1376 	iter = i915_gem_object_get_sg(obj, view->partial.offset, &offset);
1377 	GEM_BUG_ON(!iter);
1378 
1379 	sg = st->sgl;
1380 	st->nents = 0;
1381 	do {
1382 		unsigned int len;
1383 
1384 		len = min(iter->length - (offset << PAGE_SHIFT),
1385 			  count << PAGE_SHIFT);
1386 		sg_set_page(sg, NULL, len, 0);
1387 		sg_dma_address(sg) =
1388 			sg_dma_address(iter) + (offset << PAGE_SHIFT);
1389 		sg_dma_len(sg) = len;
1390 
1391 		st->nents++;
1392 		count -= len >> PAGE_SHIFT;
1393 		if (count == 0) {
1394 			sg_mark_end(sg);
1395 			i915_sg_trim(st); /* Drop any unused tail entries. */
1396 
1397 			return st;
1398 		}
1399 
1400 		sg = __sg_next(sg);
1401 		iter = __sg_next(iter);
1402 		offset = 0;
1403 	} while (1);
1404 
1405 err_sg_alloc:
1406 	kfree(st);
1407 err_st_alloc:
1408 	return ERR_PTR(ret);
1409 }
1410 
1411 static int
1412 i915_get_ggtt_vma_pages(struct i915_vma *vma)
1413 {
1414 	int ret;
1415 
1416 	/*
1417 	 * The vma->pages are only valid within the lifespan of the borrowed
1418 	 * obj->mm.pages. When the obj->mm.pages sg_table is regenerated, so
1419 	 * must be the vma->pages. A simple rule is that vma->pages must only
1420 	 * be accessed when the obj->mm.pages are pinned.
1421 	 */
1422 	GEM_BUG_ON(!i915_gem_object_has_pinned_pages(vma->obj));
1423 
1424 	switch (vma->ggtt_view.type) {
1425 	default:
1426 		GEM_BUG_ON(vma->ggtt_view.type);
1427 		/* fall through */
1428 	case I915_GGTT_VIEW_NORMAL:
1429 		vma->pages = vma->obj->mm.pages;
1430 		return 0;
1431 
1432 	case I915_GGTT_VIEW_ROTATED:
1433 		vma->pages =
1434 			intel_rotate_pages(&vma->ggtt_view.rotated, vma->obj);
1435 		break;
1436 
1437 	case I915_GGTT_VIEW_REMAPPED:
1438 		vma->pages =
1439 			intel_remap_pages(&vma->ggtt_view.remapped, vma->obj);
1440 		break;
1441 
1442 	case I915_GGTT_VIEW_PARTIAL:
1443 		vma->pages = intel_partial_pages(&vma->ggtt_view, vma->obj);
1444 		break;
1445 	}
1446 
1447 	ret = 0;
1448 	if (IS_ERR(vma->pages)) {
1449 		ret = PTR_ERR(vma->pages);
1450 		vma->pages = NULL;
1451 		drm_err(&vma->vm->i915->drm,
1452 			"Failed to get pages for VMA view type %u (%d)!\n",
1453 			vma->ggtt_view.type, ret);
1454 	}
1455 	return ret;
1456 }
1457