xref: /openbmc/linux/drivers/gpu/drm/i915/i915_gem_gtt.c (revision bbde9fc1824aab58bc78c084163007dd6c03fe5b)
1 /*
2  * Copyright © 2010 Daniel Vetter
3  * Copyright © 2011-2014 Intel Corporation
4  *
5  * Permission is hereby granted, free of charge, to any person obtaining a
6  * copy of this software and associated documentation files (the "Software"),
7  * to deal in the Software without restriction, including without limitation
8  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
9  * and/or sell copies of the Software, and to permit persons to whom the
10  * Software is furnished to do so, subject to the following conditions:
11  *
12  * The above copyright notice and this permission notice (including the next
13  * paragraph) shall be included in all copies or substantial portions of the
14  * Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
21  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
22  * IN THE SOFTWARE.
23  *
24  */
25 
26 #include <linux/seq_file.h>
27 #include <drm/drmP.h>
28 #include <drm/i915_drm.h>
29 #include "i915_drv.h"
30 #include "i915_vgpu.h"
31 #include "i915_trace.h"
32 #include "intel_drv.h"
33 
34 /**
35  * DOC: Global GTT views
36  *
37  * Background and previous state
38  *
39  * Historically objects could exists (be bound) in global GTT space only as
40  * singular instances with a view representing all of the object's backing pages
41  * in a linear fashion. This view will be called a normal view.
42  *
43  * To support multiple views of the same object, where the number of mapped
44  * pages is not equal to the backing store, or where the layout of the pages
45  * is not linear, concept of a GGTT view was added.
46  *
47  * One example of an alternative view is a stereo display driven by a single
48  * image. In this case we would have a framebuffer looking like this
49  * (2x2 pages):
50  *
51  *    12
52  *    34
53  *
54  * Above would represent a normal GGTT view as normally mapped for GPU or CPU
55  * rendering. In contrast, fed to the display engine would be an alternative
56  * view which could look something like this:
57  *
58  *   1212
59  *   3434
60  *
61  * In this example both the size and layout of pages in the alternative view is
62  * different from the normal view.
63  *
64  * Implementation and usage
65  *
66  * GGTT views are implemented using VMAs and are distinguished via enum
67  * i915_ggtt_view_type and struct i915_ggtt_view.
68  *
69  * A new flavour of core GEM functions which work with GGTT bound objects were
70  * added with the _ggtt_ infix, and sometimes with _view postfix to avoid
71  * renaming  in large amounts of code. They take the struct i915_ggtt_view
72  * parameter encapsulating all metadata required to implement a view.
73  *
74  * As a helper for callers which are only interested in the normal view,
75  * globally const i915_ggtt_view_normal singleton instance exists. All old core
76  * GEM API functions, the ones not taking the view parameter, are operating on,
77  * or with the normal GGTT view.
78  *
79  * Code wanting to add or use a new GGTT view needs to:
80  *
81  * 1. Add a new enum with a suitable name.
82  * 2. Extend the metadata in the i915_ggtt_view structure if required.
83  * 3. Add support to i915_get_vma_pages().
84  *
85  * New views are required to build a scatter-gather table from within the
86  * i915_get_vma_pages function. This table is stored in the vma.ggtt_view and
87  * exists for the lifetime of an VMA.
88  *
89  * Core API is designed to have copy semantics which means that passed in
90  * struct i915_ggtt_view does not need to be persistent (left around after
91  * calling the core API functions).
92  *
93  */
94 
95 static int
96 i915_get_ggtt_vma_pages(struct i915_vma *vma);
97 
98 const struct i915_ggtt_view i915_ggtt_view_normal;
99 const struct i915_ggtt_view i915_ggtt_view_rotated = {
100         .type = I915_GGTT_VIEW_ROTATED
101 };
102 
103 static int sanitize_enable_ppgtt(struct drm_device *dev, int enable_ppgtt)
104 {
105 	bool has_aliasing_ppgtt;
106 	bool has_full_ppgtt;
107 
108 	has_aliasing_ppgtt = INTEL_INFO(dev)->gen >= 6;
109 	has_full_ppgtt = INTEL_INFO(dev)->gen >= 7;
110 
111 	if (intel_vgpu_active(dev))
112 		has_full_ppgtt = false; /* emulation is too hard */
113 
114 	/*
115 	 * We don't allow disabling PPGTT for gen9+ as it's a requirement for
116 	 * execlists, the sole mechanism available to submit work.
117 	 */
118 	if (INTEL_INFO(dev)->gen < 9 &&
119 	    (enable_ppgtt == 0 || !has_aliasing_ppgtt))
120 		return 0;
121 
122 	if (enable_ppgtt == 1)
123 		return 1;
124 
125 	if (enable_ppgtt == 2 && has_full_ppgtt)
126 		return 2;
127 
128 #ifdef CONFIG_INTEL_IOMMU
129 	/* Disable ppgtt on SNB if VT-d is on. */
130 	if (INTEL_INFO(dev)->gen == 6 && intel_iommu_gfx_mapped) {
131 		DRM_INFO("Disabling PPGTT because VT-d is on\n");
132 		return 0;
133 	}
134 #endif
135 
136 	/* Early VLV doesn't have this */
137 	if (IS_VALLEYVIEW(dev) && !IS_CHERRYVIEW(dev) &&
138 	    dev->pdev->revision < 0xb) {
139 		DRM_DEBUG_DRIVER("disabling PPGTT on pre-B3 step VLV\n");
140 		return 0;
141 	}
142 
143 	if (INTEL_INFO(dev)->gen >= 8 && i915.enable_execlists)
144 		return 2;
145 	else
146 		return has_aliasing_ppgtt ? 1 : 0;
147 }
148 
149 static int ppgtt_bind_vma(struct i915_vma *vma,
150 			  enum i915_cache_level cache_level,
151 			  u32 unused)
152 {
153 	u32 pte_flags = 0;
154 
155 	/* Currently applicable only to VLV */
156 	if (vma->obj->gt_ro)
157 		pte_flags |= PTE_READ_ONLY;
158 
159 	vma->vm->insert_entries(vma->vm, vma->obj->pages, vma->node.start,
160 				cache_level, pte_flags);
161 
162 	return 0;
163 }
164 
165 static void ppgtt_unbind_vma(struct i915_vma *vma)
166 {
167 	vma->vm->clear_range(vma->vm,
168 			     vma->node.start,
169 			     vma->obj->base.size,
170 			     true);
171 }
172 
173 static gen8_pte_t gen8_pte_encode(dma_addr_t addr,
174 				  enum i915_cache_level level,
175 				  bool valid)
176 {
177 	gen8_pte_t pte = valid ? _PAGE_PRESENT | _PAGE_RW : 0;
178 	pte |= addr;
179 
180 	switch (level) {
181 	case I915_CACHE_NONE:
182 		pte |= PPAT_UNCACHED_INDEX;
183 		break;
184 	case I915_CACHE_WT:
185 		pte |= PPAT_DISPLAY_ELLC_INDEX;
186 		break;
187 	default:
188 		pte |= PPAT_CACHED_INDEX;
189 		break;
190 	}
191 
192 	return pte;
193 }
194 
195 static gen8_pde_t gen8_pde_encode(struct drm_device *dev,
196 				  dma_addr_t addr,
197 				  enum i915_cache_level level)
198 {
199 	gen8_pde_t pde = _PAGE_PRESENT | _PAGE_RW;
200 	pde |= addr;
201 	if (level != I915_CACHE_NONE)
202 		pde |= PPAT_CACHED_PDE_INDEX;
203 	else
204 		pde |= PPAT_UNCACHED_INDEX;
205 	return pde;
206 }
207 
208 static gen6_pte_t snb_pte_encode(dma_addr_t addr,
209 				 enum i915_cache_level level,
210 				 bool valid, u32 unused)
211 {
212 	gen6_pte_t pte = valid ? GEN6_PTE_VALID : 0;
213 	pte |= GEN6_PTE_ADDR_ENCODE(addr);
214 
215 	switch (level) {
216 	case I915_CACHE_L3_LLC:
217 	case I915_CACHE_LLC:
218 		pte |= GEN6_PTE_CACHE_LLC;
219 		break;
220 	case I915_CACHE_NONE:
221 		pte |= GEN6_PTE_UNCACHED;
222 		break;
223 	default:
224 		MISSING_CASE(level);
225 	}
226 
227 	return pte;
228 }
229 
230 static gen6_pte_t ivb_pte_encode(dma_addr_t addr,
231 				 enum i915_cache_level level,
232 				 bool valid, u32 unused)
233 {
234 	gen6_pte_t pte = valid ? GEN6_PTE_VALID : 0;
235 	pte |= GEN6_PTE_ADDR_ENCODE(addr);
236 
237 	switch (level) {
238 	case I915_CACHE_L3_LLC:
239 		pte |= GEN7_PTE_CACHE_L3_LLC;
240 		break;
241 	case I915_CACHE_LLC:
242 		pte |= GEN6_PTE_CACHE_LLC;
243 		break;
244 	case I915_CACHE_NONE:
245 		pte |= GEN6_PTE_UNCACHED;
246 		break;
247 	default:
248 		MISSING_CASE(level);
249 	}
250 
251 	return pte;
252 }
253 
254 static gen6_pte_t byt_pte_encode(dma_addr_t addr,
255 				 enum i915_cache_level level,
256 				 bool valid, u32 flags)
257 {
258 	gen6_pte_t pte = valid ? GEN6_PTE_VALID : 0;
259 	pte |= GEN6_PTE_ADDR_ENCODE(addr);
260 
261 	if (!(flags & PTE_READ_ONLY))
262 		pte |= BYT_PTE_WRITEABLE;
263 
264 	if (level != I915_CACHE_NONE)
265 		pte |= BYT_PTE_SNOOPED_BY_CPU_CACHES;
266 
267 	return pte;
268 }
269 
270 static gen6_pte_t hsw_pte_encode(dma_addr_t addr,
271 				 enum i915_cache_level level,
272 				 bool valid, u32 unused)
273 {
274 	gen6_pte_t pte = valid ? GEN6_PTE_VALID : 0;
275 	pte |= HSW_PTE_ADDR_ENCODE(addr);
276 
277 	if (level != I915_CACHE_NONE)
278 		pte |= HSW_WB_LLC_AGE3;
279 
280 	return pte;
281 }
282 
283 static gen6_pte_t iris_pte_encode(dma_addr_t addr,
284 				  enum i915_cache_level level,
285 				  bool valid, u32 unused)
286 {
287 	gen6_pte_t pte = valid ? GEN6_PTE_VALID : 0;
288 	pte |= HSW_PTE_ADDR_ENCODE(addr);
289 
290 	switch (level) {
291 	case I915_CACHE_NONE:
292 		break;
293 	case I915_CACHE_WT:
294 		pte |= HSW_WT_ELLC_LLC_AGE3;
295 		break;
296 	default:
297 		pte |= HSW_WB_ELLC_LLC_AGE3;
298 		break;
299 	}
300 
301 	return pte;
302 }
303 
304 #define i915_dma_unmap_single(px, dev) \
305 	__i915_dma_unmap_single((px)->daddr, dev)
306 
307 static void __i915_dma_unmap_single(dma_addr_t daddr,
308 				    struct drm_device *dev)
309 {
310 	struct device *device = &dev->pdev->dev;
311 
312 	dma_unmap_page(device, daddr, 4096, PCI_DMA_BIDIRECTIONAL);
313 }
314 
315 /**
316  * i915_dma_map_single() - Create a dma mapping for a page table/dir/etc.
317  * @px:	Page table/dir/etc to get a DMA map for
318  * @dev:	drm device
319  *
320  * Page table allocations are unified across all gens. They always require a
321  * single 4k allocation, as well as a DMA mapping. If we keep the structs
322  * symmetric here, the simple macro covers us for every page table type.
323  *
324  * Return: 0 if success.
325  */
326 #define i915_dma_map_single(px, dev) \
327 	i915_dma_map_page_single((px)->page, (dev), &(px)->daddr)
328 
329 static int i915_dma_map_page_single(struct page *page,
330 				    struct drm_device *dev,
331 				    dma_addr_t *daddr)
332 {
333 	struct device *device = &dev->pdev->dev;
334 
335 	*daddr = dma_map_page(device, page, 0, 4096, PCI_DMA_BIDIRECTIONAL);
336 	if (dma_mapping_error(device, *daddr))
337 		return -ENOMEM;
338 
339 	return 0;
340 }
341 
342 static void unmap_and_free_pt(struct i915_page_table *pt,
343 			       struct drm_device *dev)
344 {
345 	if (WARN_ON(!pt->page))
346 		return;
347 
348 	i915_dma_unmap_single(pt, dev);
349 	__free_page(pt->page);
350 	kfree(pt->used_ptes);
351 	kfree(pt);
352 }
353 
354 static void gen8_initialize_pt(struct i915_address_space *vm,
355 			       struct i915_page_table *pt)
356 {
357 	gen8_pte_t *pt_vaddr, scratch_pte;
358 	int i;
359 
360 	pt_vaddr = kmap_atomic(pt->page);
361 	scratch_pte = gen8_pte_encode(vm->scratch.addr,
362 				      I915_CACHE_LLC, true);
363 
364 	for (i = 0; i < GEN8_PTES; i++)
365 		pt_vaddr[i] = scratch_pte;
366 
367 	if (!HAS_LLC(vm->dev))
368 		drm_clflush_virt_range(pt_vaddr, PAGE_SIZE);
369 	kunmap_atomic(pt_vaddr);
370 }
371 
372 static struct i915_page_table *alloc_pt_single(struct drm_device *dev)
373 {
374 	struct i915_page_table *pt;
375 	const size_t count = INTEL_INFO(dev)->gen >= 8 ?
376 		GEN8_PTES : GEN6_PTES;
377 	int ret = -ENOMEM;
378 
379 	pt = kzalloc(sizeof(*pt), GFP_KERNEL);
380 	if (!pt)
381 		return ERR_PTR(-ENOMEM);
382 
383 	pt->used_ptes = kcalloc(BITS_TO_LONGS(count), sizeof(*pt->used_ptes),
384 				GFP_KERNEL);
385 
386 	if (!pt->used_ptes)
387 		goto fail_bitmap;
388 
389 	pt->page = alloc_page(GFP_KERNEL);
390 	if (!pt->page)
391 		goto fail_page;
392 
393 	ret = i915_dma_map_single(pt, dev);
394 	if (ret)
395 		goto fail_dma;
396 
397 	return pt;
398 
399 fail_dma:
400 	__free_page(pt->page);
401 fail_page:
402 	kfree(pt->used_ptes);
403 fail_bitmap:
404 	kfree(pt);
405 
406 	return ERR_PTR(ret);
407 }
408 
409 static void unmap_and_free_pd(struct i915_page_directory *pd,
410 			      struct drm_device *dev)
411 {
412 	if (pd->page) {
413 		i915_dma_unmap_single(pd, dev);
414 		__free_page(pd->page);
415 		kfree(pd->used_pdes);
416 		kfree(pd);
417 	}
418 }
419 
420 static struct i915_page_directory *alloc_pd_single(struct drm_device *dev)
421 {
422 	struct i915_page_directory *pd;
423 	int ret = -ENOMEM;
424 
425 	pd = kzalloc(sizeof(*pd), GFP_KERNEL);
426 	if (!pd)
427 		return ERR_PTR(-ENOMEM);
428 
429 	pd->used_pdes = kcalloc(BITS_TO_LONGS(I915_PDES),
430 				sizeof(*pd->used_pdes), GFP_KERNEL);
431 	if (!pd->used_pdes)
432 		goto free_pd;
433 
434 	pd->page = alloc_page(GFP_KERNEL);
435 	if (!pd->page)
436 		goto free_bitmap;
437 
438 	ret = i915_dma_map_single(pd, dev);
439 	if (ret)
440 		goto free_page;
441 
442 	return pd;
443 
444 free_page:
445 	__free_page(pd->page);
446 free_bitmap:
447 	kfree(pd->used_pdes);
448 free_pd:
449 	kfree(pd);
450 
451 	return ERR_PTR(ret);
452 }
453 
454 /* Broadwell Page Directory Pointer Descriptors */
455 static int gen8_write_pdp(struct intel_engine_cs *ring,
456 			  unsigned entry,
457 			  dma_addr_t addr)
458 {
459 	int ret;
460 
461 	BUG_ON(entry >= 4);
462 
463 	ret = intel_ring_begin(ring, 6);
464 	if (ret)
465 		return ret;
466 
467 	intel_ring_emit(ring, MI_LOAD_REGISTER_IMM(1));
468 	intel_ring_emit(ring, GEN8_RING_PDP_UDW(ring, entry));
469 	intel_ring_emit(ring, upper_32_bits(addr));
470 	intel_ring_emit(ring, MI_LOAD_REGISTER_IMM(1));
471 	intel_ring_emit(ring, GEN8_RING_PDP_LDW(ring, entry));
472 	intel_ring_emit(ring, lower_32_bits(addr));
473 	intel_ring_advance(ring);
474 
475 	return 0;
476 }
477 
478 static int gen8_mm_switch(struct i915_hw_ppgtt *ppgtt,
479 			  struct intel_engine_cs *ring)
480 {
481 	int i, ret;
482 
483 	for (i = GEN8_LEGACY_PDPES - 1; i >= 0; i--) {
484 		struct i915_page_directory *pd = ppgtt->pdp.page_directory[i];
485 		dma_addr_t pd_daddr = pd ? pd->daddr : ppgtt->scratch_pd->daddr;
486 		/* The page directory might be NULL, but we need to clear out
487 		 * whatever the previous context might have used. */
488 		ret = gen8_write_pdp(ring, i, pd_daddr);
489 		if (ret)
490 			return ret;
491 	}
492 
493 	return 0;
494 }
495 
496 static void gen8_ppgtt_clear_range(struct i915_address_space *vm,
497 				   uint64_t start,
498 				   uint64_t length,
499 				   bool use_scratch)
500 {
501 	struct i915_hw_ppgtt *ppgtt =
502 		container_of(vm, struct i915_hw_ppgtt, base);
503 	gen8_pte_t *pt_vaddr, scratch_pte;
504 	unsigned pdpe = start >> GEN8_PDPE_SHIFT & GEN8_PDPE_MASK;
505 	unsigned pde = start >> GEN8_PDE_SHIFT & GEN8_PDE_MASK;
506 	unsigned pte = start >> GEN8_PTE_SHIFT & GEN8_PTE_MASK;
507 	unsigned num_entries = length >> PAGE_SHIFT;
508 	unsigned last_pte, i;
509 
510 	scratch_pte = gen8_pte_encode(ppgtt->base.scratch.addr,
511 				      I915_CACHE_LLC, use_scratch);
512 
513 	while (num_entries) {
514 		struct i915_page_directory *pd;
515 		struct i915_page_table *pt;
516 		struct page *page_table;
517 
518 		if (WARN_ON(!ppgtt->pdp.page_directory[pdpe]))
519 			break;
520 
521 		pd = ppgtt->pdp.page_directory[pdpe];
522 
523 		if (WARN_ON(!pd->page_table[pde]))
524 			break;
525 
526 		pt = pd->page_table[pde];
527 
528 		if (WARN_ON(!pt->page))
529 			break;
530 
531 		page_table = pt->page;
532 
533 		last_pte = pte + num_entries;
534 		if (last_pte > GEN8_PTES)
535 			last_pte = GEN8_PTES;
536 
537 		pt_vaddr = kmap_atomic(page_table);
538 
539 		for (i = pte; i < last_pte; i++) {
540 			pt_vaddr[i] = scratch_pte;
541 			num_entries--;
542 		}
543 
544 		if (!HAS_LLC(ppgtt->base.dev))
545 			drm_clflush_virt_range(pt_vaddr, PAGE_SIZE);
546 		kunmap_atomic(pt_vaddr);
547 
548 		pte = 0;
549 		if (++pde == I915_PDES) {
550 			pdpe++;
551 			pde = 0;
552 		}
553 	}
554 }
555 
556 static void gen8_ppgtt_insert_entries(struct i915_address_space *vm,
557 				      struct sg_table *pages,
558 				      uint64_t start,
559 				      enum i915_cache_level cache_level, u32 unused)
560 {
561 	struct i915_hw_ppgtt *ppgtt =
562 		container_of(vm, struct i915_hw_ppgtt, base);
563 	gen8_pte_t *pt_vaddr;
564 	unsigned pdpe = start >> GEN8_PDPE_SHIFT & GEN8_PDPE_MASK;
565 	unsigned pde = start >> GEN8_PDE_SHIFT & GEN8_PDE_MASK;
566 	unsigned pte = start >> GEN8_PTE_SHIFT & GEN8_PTE_MASK;
567 	struct sg_page_iter sg_iter;
568 
569 	pt_vaddr = NULL;
570 
571 	for_each_sg_page(pages->sgl, &sg_iter, pages->nents, 0) {
572 		if (WARN_ON(pdpe >= GEN8_LEGACY_PDPES))
573 			break;
574 
575 		if (pt_vaddr == NULL) {
576 			struct i915_page_directory *pd = ppgtt->pdp.page_directory[pdpe];
577 			struct i915_page_table *pt = pd->page_table[pde];
578 			struct page *page_table = pt->page;
579 
580 			pt_vaddr = kmap_atomic(page_table);
581 		}
582 
583 		pt_vaddr[pte] =
584 			gen8_pte_encode(sg_page_iter_dma_address(&sg_iter),
585 					cache_level, true);
586 		if (++pte == GEN8_PTES) {
587 			if (!HAS_LLC(ppgtt->base.dev))
588 				drm_clflush_virt_range(pt_vaddr, PAGE_SIZE);
589 			kunmap_atomic(pt_vaddr);
590 			pt_vaddr = NULL;
591 			if (++pde == I915_PDES) {
592 				pdpe++;
593 				pde = 0;
594 			}
595 			pte = 0;
596 		}
597 	}
598 	if (pt_vaddr) {
599 		if (!HAS_LLC(ppgtt->base.dev))
600 			drm_clflush_virt_range(pt_vaddr, PAGE_SIZE);
601 		kunmap_atomic(pt_vaddr);
602 	}
603 }
604 
605 static void __gen8_do_map_pt(gen8_pde_t * const pde,
606 			     struct i915_page_table *pt,
607 			     struct drm_device *dev)
608 {
609 	gen8_pde_t entry =
610 		gen8_pde_encode(dev, pt->daddr, I915_CACHE_LLC);
611 	*pde = entry;
612 }
613 
614 static void gen8_initialize_pd(struct i915_address_space *vm,
615 			       struct i915_page_directory *pd)
616 {
617 	struct i915_hw_ppgtt *ppgtt =
618 			container_of(vm, struct i915_hw_ppgtt, base);
619 	gen8_pde_t *page_directory;
620 	struct i915_page_table *pt;
621 	int i;
622 
623 	page_directory = kmap_atomic(pd->page);
624 	pt = ppgtt->scratch_pt;
625 	for (i = 0; i < I915_PDES; i++)
626 		/* Map the PDE to the page table */
627 		__gen8_do_map_pt(page_directory + i, pt, vm->dev);
628 
629 	if (!HAS_LLC(vm->dev))
630 		drm_clflush_virt_range(page_directory, PAGE_SIZE);
631 	kunmap_atomic(page_directory);
632 }
633 
634 static void gen8_free_page_tables(struct i915_page_directory *pd, struct drm_device *dev)
635 {
636 	int i;
637 
638 	if (!pd->page)
639 		return;
640 
641 	for_each_set_bit(i, pd->used_pdes, I915_PDES) {
642 		if (WARN_ON(!pd->page_table[i]))
643 			continue;
644 
645 		unmap_and_free_pt(pd->page_table[i], dev);
646 		pd->page_table[i] = NULL;
647 	}
648 }
649 
650 static void gen8_ppgtt_cleanup(struct i915_address_space *vm)
651 {
652 	struct i915_hw_ppgtt *ppgtt =
653 		container_of(vm, struct i915_hw_ppgtt, base);
654 	int i;
655 
656 	for_each_set_bit(i, ppgtt->pdp.used_pdpes, GEN8_LEGACY_PDPES) {
657 		if (WARN_ON(!ppgtt->pdp.page_directory[i]))
658 			continue;
659 
660 		gen8_free_page_tables(ppgtt->pdp.page_directory[i], ppgtt->base.dev);
661 		unmap_and_free_pd(ppgtt->pdp.page_directory[i], ppgtt->base.dev);
662 	}
663 
664 	unmap_and_free_pd(ppgtt->scratch_pd, ppgtt->base.dev);
665 	unmap_and_free_pt(ppgtt->scratch_pt, ppgtt->base.dev);
666 }
667 
668 /**
669  * gen8_ppgtt_alloc_pagetabs() - Allocate page tables for VA range.
670  * @ppgtt:	Master ppgtt structure.
671  * @pd:		Page directory for this address range.
672  * @start:	Starting virtual address to begin allocations.
673  * @length	Size of the allocations.
674  * @new_pts:	Bitmap set by function with new allocations. Likely used by the
675  *		caller to free on error.
676  *
677  * Allocate the required number of page tables. Extremely similar to
678  * gen8_ppgtt_alloc_page_directories(). The main difference is here we are limited by
679  * the page directory boundary (instead of the page directory pointer). That
680  * boundary is 1GB virtual. Therefore, unlike gen8_ppgtt_alloc_page_directories(), it is
681  * possible, and likely that the caller will need to use multiple calls of this
682  * function to achieve the appropriate allocation.
683  *
684  * Return: 0 if success; negative error code otherwise.
685  */
686 static int gen8_ppgtt_alloc_pagetabs(struct i915_hw_ppgtt *ppgtt,
687 				     struct i915_page_directory *pd,
688 				     uint64_t start,
689 				     uint64_t length,
690 				     unsigned long *new_pts)
691 {
692 	struct drm_device *dev = ppgtt->base.dev;
693 	struct i915_page_table *pt;
694 	uint64_t temp;
695 	uint32_t pde;
696 
697 	gen8_for_each_pde(pt, pd, start, length, temp, pde) {
698 		/* Don't reallocate page tables */
699 		if (pt) {
700 			/* Scratch is never allocated this way */
701 			WARN_ON(pt == ppgtt->scratch_pt);
702 			continue;
703 		}
704 
705 		pt = alloc_pt_single(dev);
706 		if (IS_ERR(pt))
707 			goto unwind_out;
708 
709 		gen8_initialize_pt(&ppgtt->base, pt);
710 		pd->page_table[pde] = pt;
711 		set_bit(pde, new_pts);
712 	}
713 
714 	return 0;
715 
716 unwind_out:
717 	for_each_set_bit(pde, new_pts, I915_PDES)
718 		unmap_and_free_pt(pd->page_table[pde], dev);
719 
720 	return -ENOMEM;
721 }
722 
723 /**
724  * gen8_ppgtt_alloc_page_directories() - Allocate page directories for VA range.
725  * @ppgtt:	Master ppgtt structure.
726  * @pdp:	Page directory pointer for this address range.
727  * @start:	Starting virtual address to begin allocations.
728  * @length	Size of the allocations.
729  * @new_pds	Bitmap set by function with new allocations. Likely used by the
730  *		caller to free on error.
731  *
732  * Allocate the required number of page directories starting at the pde index of
733  * @start, and ending at the pde index @start + @length. This function will skip
734  * over already allocated page directories within the range, and only allocate
735  * new ones, setting the appropriate pointer within the pdp as well as the
736  * correct position in the bitmap @new_pds.
737  *
738  * The function will only allocate the pages within the range for a give page
739  * directory pointer. In other words, if @start + @length straddles a virtually
740  * addressed PDP boundary (512GB for 4k pages), there will be more allocations
741  * required by the caller, This is not currently possible, and the BUG in the
742  * code will prevent it.
743  *
744  * Return: 0 if success; negative error code otherwise.
745  */
746 static int gen8_ppgtt_alloc_page_directories(struct i915_hw_ppgtt *ppgtt,
747 				     struct i915_page_directory_pointer *pdp,
748 				     uint64_t start,
749 				     uint64_t length,
750 				     unsigned long *new_pds)
751 {
752 	struct drm_device *dev = ppgtt->base.dev;
753 	struct i915_page_directory *pd;
754 	uint64_t temp;
755 	uint32_t pdpe;
756 
757 	WARN_ON(!bitmap_empty(new_pds, GEN8_LEGACY_PDPES));
758 
759 	/* FIXME: upper bound must not overflow 32 bits  */
760 	WARN_ON((start + length) > (1ULL << 32));
761 
762 	gen8_for_each_pdpe(pd, pdp, start, length, temp, pdpe) {
763 		if (pd)
764 			continue;
765 
766 		pd = alloc_pd_single(dev);
767 		if (IS_ERR(pd))
768 			goto unwind_out;
769 
770 		gen8_initialize_pd(&ppgtt->base, pd);
771 		pdp->page_directory[pdpe] = pd;
772 		set_bit(pdpe, new_pds);
773 	}
774 
775 	return 0;
776 
777 unwind_out:
778 	for_each_set_bit(pdpe, new_pds, GEN8_LEGACY_PDPES)
779 		unmap_and_free_pd(pdp->page_directory[pdpe], dev);
780 
781 	return -ENOMEM;
782 }
783 
784 static void
785 free_gen8_temp_bitmaps(unsigned long *new_pds, unsigned long **new_pts)
786 {
787 	int i;
788 
789 	for (i = 0; i < GEN8_LEGACY_PDPES; i++)
790 		kfree(new_pts[i]);
791 	kfree(new_pts);
792 	kfree(new_pds);
793 }
794 
795 /* Fills in the page directory bitmap, and the array of page tables bitmap. Both
796  * of these are based on the number of PDPEs in the system.
797  */
798 static
799 int __must_check alloc_gen8_temp_bitmaps(unsigned long **new_pds,
800 					 unsigned long ***new_pts)
801 {
802 	int i;
803 	unsigned long *pds;
804 	unsigned long **pts;
805 
806 	pds = kcalloc(BITS_TO_LONGS(GEN8_LEGACY_PDPES), sizeof(unsigned long), GFP_KERNEL);
807 	if (!pds)
808 		return -ENOMEM;
809 
810 	pts = kcalloc(GEN8_LEGACY_PDPES, sizeof(unsigned long *), GFP_KERNEL);
811 	if (!pts) {
812 		kfree(pds);
813 		return -ENOMEM;
814 	}
815 
816 	for (i = 0; i < GEN8_LEGACY_PDPES; i++) {
817 		pts[i] = kcalloc(BITS_TO_LONGS(I915_PDES),
818 				 sizeof(unsigned long), GFP_KERNEL);
819 		if (!pts[i])
820 			goto err_out;
821 	}
822 
823 	*new_pds = pds;
824 	*new_pts = pts;
825 
826 	return 0;
827 
828 err_out:
829 	free_gen8_temp_bitmaps(pds, pts);
830 	return -ENOMEM;
831 }
832 
833 static int gen8_alloc_va_range(struct i915_address_space *vm,
834 			       uint64_t start,
835 			       uint64_t length)
836 {
837 	struct i915_hw_ppgtt *ppgtt =
838 		container_of(vm, struct i915_hw_ppgtt, base);
839 	unsigned long *new_page_dirs, **new_page_tables;
840 	struct i915_page_directory *pd;
841 	const uint64_t orig_start = start;
842 	const uint64_t orig_length = length;
843 	uint64_t temp;
844 	uint32_t pdpe;
845 	int ret;
846 
847 	/* Wrap is never okay since we can only represent 48b, and we don't
848 	 * actually use the other side of the canonical address space.
849 	 */
850 	if (WARN_ON(start + length < start))
851 		return -ERANGE;
852 
853 	ret = alloc_gen8_temp_bitmaps(&new_page_dirs, &new_page_tables);
854 	if (ret)
855 		return ret;
856 
857 	/* Do the allocations first so we can easily bail out */
858 	ret = gen8_ppgtt_alloc_page_directories(ppgtt, &ppgtt->pdp, start, length,
859 					new_page_dirs);
860 	if (ret) {
861 		free_gen8_temp_bitmaps(new_page_dirs, new_page_tables);
862 		return ret;
863 	}
864 
865 	/* For every page directory referenced, allocate page tables */
866 	gen8_for_each_pdpe(pd, &ppgtt->pdp, start, length, temp, pdpe) {
867 		ret = gen8_ppgtt_alloc_pagetabs(ppgtt, pd, start, length,
868 						new_page_tables[pdpe]);
869 		if (ret)
870 			goto err_out;
871 	}
872 
873 	start = orig_start;
874 	length = orig_length;
875 
876 	/* Allocations have completed successfully, so set the bitmaps, and do
877 	 * the mappings. */
878 	gen8_for_each_pdpe(pd, &ppgtt->pdp, start, length, temp, pdpe) {
879 		gen8_pde_t *const page_directory = kmap_atomic(pd->page);
880 		struct i915_page_table *pt;
881 		uint64_t pd_len = gen8_clamp_pd(start, length);
882 		uint64_t pd_start = start;
883 		uint32_t pde;
884 
885 		/* Every pd should be allocated, we just did that above. */
886 		WARN_ON(!pd);
887 
888 		gen8_for_each_pde(pt, pd, pd_start, pd_len, temp, pde) {
889 			/* Same reasoning as pd */
890 			WARN_ON(!pt);
891 			WARN_ON(!pd_len);
892 			WARN_ON(!gen8_pte_count(pd_start, pd_len));
893 
894 			/* Set our used ptes within the page table */
895 			bitmap_set(pt->used_ptes,
896 				   gen8_pte_index(pd_start),
897 				   gen8_pte_count(pd_start, pd_len));
898 
899 			/* Our pde is now pointing to the pagetable, pt */
900 			set_bit(pde, pd->used_pdes);
901 
902 			/* Map the PDE to the page table */
903 			__gen8_do_map_pt(page_directory + pde, pt, vm->dev);
904 
905 			/* NB: We haven't yet mapped ptes to pages. At this
906 			 * point we're still relying on insert_entries() */
907 		}
908 
909 		if (!HAS_LLC(vm->dev))
910 			drm_clflush_virt_range(page_directory, PAGE_SIZE);
911 
912 		kunmap_atomic(page_directory);
913 
914 		set_bit(pdpe, ppgtt->pdp.used_pdpes);
915 	}
916 
917 	free_gen8_temp_bitmaps(new_page_dirs, new_page_tables);
918 	return 0;
919 
920 err_out:
921 	while (pdpe--) {
922 		for_each_set_bit(temp, new_page_tables[pdpe], I915_PDES)
923 			unmap_and_free_pt(ppgtt->pdp.page_directory[pdpe]->page_table[temp], vm->dev);
924 	}
925 
926 	for_each_set_bit(pdpe, new_page_dirs, GEN8_LEGACY_PDPES)
927 		unmap_and_free_pd(ppgtt->pdp.page_directory[pdpe], vm->dev);
928 
929 	free_gen8_temp_bitmaps(new_page_dirs, new_page_tables);
930 	return ret;
931 }
932 
933 /*
934  * GEN8 legacy ppgtt programming is accomplished through a max 4 PDP registers
935  * with a net effect resembling a 2-level page table in normal x86 terms. Each
936  * PDP represents 1GB of memory 4 * 512 * 512 * 4096 = 4GB legacy 32b address
937  * space.
938  *
939  */
940 static int gen8_ppgtt_init(struct i915_hw_ppgtt *ppgtt)
941 {
942 	ppgtt->scratch_pt = alloc_pt_single(ppgtt->base.dev);
943 	if (IS_ERR(ppgtt->scratch_pt))
944 		return PTR_ERR(ppgtt->scratch_pt);
945 
946 	ppgtt->scratch_pd = alloc_pd_single(ppgtt->base.dev);
947 	if (IS_ERR(ppgtt->scratch_pd))
948 		return PTR_ERR(ppgtt->scratch_pd);
949 
950 	gen8_initialize_pt(&ppgtt->base, ppgtt->scratch_pt);
951 	gen8_initialize_pd(&ppgtt->base, ppgtt->scratch_pd);
952 
953 	ppgtt->base.start = 0;
954 	ppgtt->base.total = 1ULL << 32;
955 	if (IS_ENABLED(CONFIG_X86_32))
956 		/* While we have a proliferation of size_t variables
957 		 * we cannot represent the full ppgtt size on 32bit,
958 		 * so limit it to the same size as the GGTT (currently
959 		 * 2GiB).
960 		 */
961 		ppgtt->base.total = to_i915(ppgtt->base.dev)->gtt.base.total;
962 	ppgtt->base.cleanup = gen8_ppgtt_cleanup;
963 	ppgtt->base.allocate_va_range = gen8_alloc_va_range;
964 	ppgtt->base.insert_entries = gen8_ppgtt_insert_entries;
965 	ppgtt->base.clear_range = gen8_ppgtt_clear_range;
966 	ppgtt->base.unbind_vma = ppgtt_unbind_vma;
967 	ppgtt->base.bind_vma = ppgtt_bind_vma;
968 
969 	ppgtt->switch_mm = gen8_mm_switch;
970 
971 	return 0;
972 }
973 
974 static void gen6_dump_ppgtt(struct i915_hw_ppgtt *ppgtt, struct seq_file *m)
975 {
976 	struct i915_address_space *vm = &ppgtt->base;
977 	struct i915_page_table *unused;
978 	gen6_pte_t scratch_pte;
979 	uint32_t pd_entry;
980 	uint32_t  pte, pde, temp;
981 	uint32_t start = ppgtt->base.start, length = ppgtt->base.total;
982 
983 	scratch_pte = vm->pte_encode(vm->scratch.addr, I915_CACHE_LLC, true, 0);
984 
985 	gen6_for_each_pde(unused, &ppgtt->pd, start, length, temp, pde) {
986 		u32 expected;
987 		gen6_pte_t *pt_vaddr;
988 		dma_addr_t pt_addr = ppgtt->pd.page_table[pde]->daddr;
989 		pd_entry = readl(ppgtt->pd_addr + pde);
990 		expected = (GEN6_PDE_ADDR_ENCODE(pt_addr) | GEN6_PDE_VALID);
991 
992 		if (pd_entry != expected)
993 			seq_printf(m, "\tPDE #%d mismatch: Actual PDE: %x Expected PDE: %x\n",
994 				   pde,
995 				   pd_entry,
996 				   expected);
997 		seq_printf(m, "\tPDE: %x\n", pd_entry);
998 
999 		pt_vaddr = kmap_atomic(ppgtt->pd.page_table[pde]->page);
1000 		for (pte = 0; pte < GEN6_PTES; pte+=4) {
1001 			unsigned long va =
1002 				(pde * PAGE_SIZE * GEN6_PTES) +
1003 				(pte * PAGE_SIZE);
1004 			int i;
1005 			bool found = false;
1006 			for (i = 0; i < 4; i++)
1007 				if (pt_vaddr[pte + i] != scratch_pte)
1008 					found = true;
1009 			if (!found)
1010 				continue;
1011 
1012 			seq_printf(m, "\t\t0x%lx [%03d,%04d]: =", va, pde, pte);
1013 			for (i = 0; i < 4; i++) {
1014 				if (pt_vaddr[pte + i] != scratch_pte)
1015 					seq_printf(m, " %08x", pt_vaddr[pte + i]);
1016 				else
1017 					seq_puts(m, "  SCRATCH ");
1018 			}
1019 			seq_puts(m, "\n");
1020 		}
1021 		kunmap_atomic(pt_vaddr);
1022 	}
1023 }
1024 
1025 /* Write pde (index) from the page directory @pd to the page table @pt */
1026 static void gen6_write_pde(struct i915_page_directory *pd,
1027 			    const int pde, struct i915_page_table *pt)
1028 {
1029 	/* Caller needs to make sure the write completes if necessary */
1030 	struct i915_hw_ppgtt *ppgtt =
1031 		container_of(pd, struct i915_hw_ppgtt, pd);
1032 	u32 pd_entry;
1033 
1034 	pd_entry = GEN6_PDE_ADDR_ENCODE(pt->daddr);
1035 	pd_entry |= GEN6_PDE_VALID;
1036 
1037 	writel(pd_entry, ppgtt->pd_addr + pde);
1038 }
1039 
1040 /* Write all the page tables found in the ppgtt structure to incrementing page
1041  * directories. */
1042 static void gen6_write_page_range(struct drm_i915_private *dev_priv,
1043 				  struct i915_page_directory *pd,
1044 				  uint32_t start, uint32_t length)
1045 {
1046 	struct i915_page_table *pt;
1047 	uint32_t pde, temp;
1048 
1049 	gen6_for_each_pde(pt, pd, start, length, temp, pde)
1050 		gen6_write_pde(pd, pde, pt);
1051 
1052 	/* Make sure write is complete before other code can use this page
1053 	 * table. Also require for WC mapped PTEs */
1054 	readl(dev_priv->gtt.gsm);
1055 }
1056 
1057 static uint32_t get_pd_offset(struct i915_hw_ppgtt *ppgtt)
1058 {
1059 	BUG_ON(ppgtt->pd.pd_offset & 0x3f);
1060 
1061 	return (ppgtt->pd.pd_offset / 64) << 16;
1062 }
1063 
1064 static int hsw_mm_switch(struct i915_hw_ppgtt *ppgtt,
1065 			 struct intel_engine_cs *ring)
1066 {
1067 	int ret;
1068 
1069 	/* NB: TLBs must be flushed and invalidated before a switch */
1070 	ret = ring->flush(ring, I915_GEM_GPU_DOMAINS, I915_GEM_GPU_DOMAINS);
1071 	if (ret)
1072 		return ret;
1073 
1074 	ret = intel_ring_begin(ring, 6);
1075 	if (ret)
1076 		return ret;
1077 
1078 	intel_ring_emit(ring, MI_LOAD_REGISTER_IMM(2));
1079 	intel_ring_emit(ring, RING_PP_DIR_DCLV(ring));
1080 	intel_ring_emit(ring, PP_DIR_DCLV_2G);
1081 	intel_ring_emit(ring, RING_PP_DIR_BASE(ring));
1082 	intel_ring_emit(ring, get_pd_offset(ppgtt));
1083 	intel_ring_emit(ring, MI_NOOP);
1084 	intel_ring_advance(ring);
1085 
1086 	return 0;
1087 }
1088 
1089 static int vgpu_mm_switch(struct i915_hw_ppgtt *ppgtt,
1090 			  struct intel_engine_cs *ring)
1091 {
1092 	struct drm_i915_private *dev_priv = to_i915(ppgtt->base.dev);
1093 
1094 	I915_WRITE(RING_PP_DIR_DCLV(ring), PP_DIR_DCLV_2G);
1095 	I915_WRITE(RING_PP_DIR_BASE(ring), get_pd_offset(ppgtt));
1096 	return 0;
1097 }
1098 
1099 static int gen7_mm_switch(struct i915_hw_ppgtt *ppgtt,
1100 			  struct intel_engine_cs *ring)
1101 {
1102 	int ret;
1103 
1104 	/* NB: TLBs must be flushed and invalidated before a switch */
1105 	ret = ring->flush(ring, I915_GEM_GPU_DOMAINS, I915_GEM_GPU_DOMAINS);
1106 	if (ret)
1107 		return ret;
1108 
1109 	ret = intel_ring_begin(ring, 6);
1110 	if (ret)
1111 		return ret;
1112 
1113 	intel_ring_emit(ring, MI_LOAD_REGISTER_IMM(2));
1114 	intel_ring_emit(ring, RING_PP_DIR_DCLV(ring));
1115 	intel_ring_emit(ring, PP_DIR_DCLV_2G);
1116 	intel_ring_emit(ring, RING_PP_DIR_BASE(ring));
1117 	intel_ring_emit(ring, get_pd_offset(ppgtt));
1118 	intel_ring_emit(ring, MI_NOOP);
1119 	intel_ring_advance(ring);
1120 
1121 	/* XXX: RCS is the only one to auto invalidate the TLBs? */
1122 	if (ring->id != RCS) {
1123 		ret = ring->flush(ring, I915_GEM_GPU_DOMAINS, I915_GEM_GPU_DOMAINS);
1124 		if (ret)
1125 			return ret;
1126 	}
1127 
1128 	return 0;
1129 }
1130 
1131 static int gen6_mm_switch(struct i915_hw_ppgtt *ppgtt,
1132 			  struct intel_engine_cs *ring)
1133 {
1134 	struct drm_device *dev = ppgtt->base.dev;
1135 	struct drm_i915_private *dev_priv = dev->dev_private;
1136 
1137 
1138 	I915_WRITE(RING_PP_DIR_DCLV(ring), PP_DIR_DCLV_2G);
1139 	I915_WRITE(RING_PP_DIR_BASE(ring), get_pd_offset(ppgtt));
1140 
1141 	POSTING_READ(RING_PP_DIR_DCLV(ring));
1142 
1143 	return 0;
1144 }
1145 
1146 static void gen8_ppgtt_enable(struct drm_device *dev)
1147 {
1148 	struct drm_i915_private *dev_priv = dev->dev_private;
1149 	struct intel_engine_cs *ring;
1150 	int j;
1151 
1152 	for_each_ring(ring, dev_priv, j) {
1153 		I915_WRITE(RING_MODE_GEN7(ring),
1154 			   _MASKED_BIT_ENABLE(GFX_PPGTT_ENABLE));
1155 	}
1156 }
1157 
1158 static void gen7_ppgtt_enable(struct drm_device *dev)
1159 {
1160 	struct drm_i915_private *dev_priv = dev->dev_private;
1161 	struct intel_engine_cs *ring;
1162 	uint32_t ecochk, ecobits;
1163 	int i;
1164 
1165 	ecobits = I915_READ(GAC_ECO_BITS);
1166 	I915_WRITE(GAC_ECO_BITS, ecobits | ECOBITS_PPGTT_CACHE64B);
1167 
1168 	ecochk = I915_READ(GAM_ECOCHK);
1169 	if (IS_HASWELL(dev)) {
1170 		ecochk |= ECOCHK_PPGTT_WB_HSW;
1171 	} else {
1172 		ecochk |= ECOCHK_PPGTT_LLC_IVB;
1173 		ecochk &= ~ECOCHK_PPGTT_GFDT_IVB;
1174 	}
1175 	I915_WRITE(GAM_ECOCHK, ecochk);
1176 
1177 	for_each_ring(ring, dev_priv, i) {
1178 		/* GFX_MODE is per-ring on gen7+ */
1179 		I915_WRITE(RING_MODE_GEN7(ring),
1180 			   _MASKED_BIT_ENABLE(GFX_PPGTT_ENABLE));
1181 	}
1182 }
1183 
1184 static void gen6_ppgtt_enable(struct drm_device *dev)
1185 {
1186 	struct drm_i915_private *dev_priv = dev->dev_private;
1187 	uint32_t ecochk, gab_ctl, ecobits;
1188 
1189 	ecobits = I915_READ(GAC_ECO_BITS);
1190 	I915_WRITE(GAC_ECO_BITS, ecobits | ECOBITS_SNB_BIT |
1191 		   ECOBITS_PPGTT_CACHE64B);
1192 
1193 	gab_ctl = I915_READ(GAB_CTL);
1194 	I915_WRITE(GAB_CTL, gab_ctl | GAB_CTL_CONT_AFTER_PAGEFAULT);
1195 
1196 	ecochk = I915_READ(GAM_ECOCHK);
1197 	I915_WRITE(GAM_ECOCHK, ecochk | ECOCHK_SNB_BIT | ECOCHK_PPGTT_CACHE64B);
1198 
1199 	I915_WRITE(GFX_MODE, _MASKED_BIT_ENABLE(GFX_PPGTT_ENABLE));
1200 }
1201 
1202 /* PPGTT support for Sandybdrige/Gen6 and later */
1203 static void gen6_ppgtt_clear_range(struct i915_address_space *vm,
1204 				   uint64_t start,
1205 				   uint64_t length,
1206 				   bool use_scratch)
1207 {
1208 	struct i915_hw_ppgtt *ppgtt =
1209 		container_of(vm, struct i915_hw_ppgtt, base);
1210 	gen6_pte_t *pt_vaddr, scratch_pte;
1211 	unsigned first_entry = start >> PAGE_SHIFT;
1212 	unsigned num_entries = length >> PAGE_SHIFT;
1213 	unsigned act_pt = first_entry / GEN6_PTES;
1214 	unsigned first_pte = first_entry % GEN6_PTES;
1215 	unsigned last_pte, i;
1216 
1217 	scratch_pte = vm->pte_encode(vm->scratch.addr, I915_CACHE_LLC, true, 0);
1218 
1219 	while (num_entries) {
1220 		last_pte = first_pte + num_entries;
1221 		if (last_pte > GEN6_PTES)
1222 			last_pte = GEN6_PTES;
1223 
1224 		pt_vaddr = kmap_atomic(ppgtt->pd.page_table[act_pt]->page);
1225 
1226 		for (i = first_pte; i < last_pte; i++)
1227 			pt_vaddr[i] = scratch_pte;
1228 
1229 		kunmap_atomic(pt_vaddr);
1230 
1231 		num_entries -= last_pte - first_pte;
1232 		first_pte = 0;
1233 		act_pt++;
1234 	}
1235 }
1236 
1237 static void gen6_ppgtt_insert_entries(struct i915_address_space *vm,
1238 				      struct sg_table *pages,
1239 				      uint64_t start,
1240 				      enum i915_cache_level cache_level, u32 flags)
1241 {
1242 	struct i915_hw_ppgtt *ppgtt =
1243 		container_of(vm, struct i915_hw_ppgtt, base);
1244 	gen6_pte_t *pt_vaddr;
1245 	unsigned first_entry = start >> PAGE_SHIFT;
1246 	unsigned act_pt = first_entry / GEN6_PTES;
1247 	unsigned act_pte = first_entry % GEN6_PTES;
1248 	struct sg_page_iter sg_iter;
1249 
1250 	pt_vaddr = NULL;
1251 	for_each_sg_page(pages->sgl, &sg_iter, pages->nents, 0) {
1252 		if (pt_vaddr == NULL)
1253 			pt_vaddr = kmap_atomic(ppgtt->pd.page_table[act_pt]->page);
1254 
1255 		pt_vaddr[act_pte] =
1256 			vm->pte_encode(sg_page_iter_dma_address(&sg_iter),
1257 				       cache_level, true, flags);
1258 
1259 		if (++act_pte == GEN6_PTES) {
1260 			kunmap_atomic(pt_vaddr);
1261 			pt_vaddr = NULL;
1262 			act_pt++;
1263 			act_pte = 0;
1264 		}
1265 	}
1266 	if (pt_vaddr)
1267 		kunmap_atomic(pt_vaddr);
1268 }
1269 
1270 /* PDE TLBs are a pain invalidate pre GEN8. It requires a context reload. If we
1271  * are switching between contexts with the same LRCA, we also must do a force
1272  * restore.
1273  */
1274 static void mark_tlbs_dirty(struct i915_hw_ppgtt *ppgtt)
1275 {
1276 	/* If current vm != vm, */
1277 	ppgtt->pd_dirty_rings = INTEL_INFO(ppgtt->base.dev)->ring_mask;
1278 }
1279 
1280 static void gen6_initialize_pt(struct i915_address_space *vm,
1281 		struct i915_page_table *pt)
1282 {
1283 	gen6_pte_t *pt_vaddr, scratch_pte;
1284 	int i;
1285 
1286 	WARN_ON(vm->scratch.addr == 0);
1287 
1288 	scratch_pte = vm->pte_encode(vm->scratch.addr,
1289 			I915_CACHE_LLC, true, 0);
1290 
1291 	pt_vaddr = kmap_atomic(pt->page);
1292 
1293 	for (i = 0; i < GEN6_PTES; i++)
1294 		pt_vaddr[i] = scratch_pte;
1295 
1296 	kunmap_atomic(pt_vaddr);
1297 }
1298 
1299 static int gen6_alloc_va_range(struct i915_address_space *vm,
1300 			       uint64_t start, uint64_t length)
1301 {
1302 	DECLARE_BITMAP(new_page_tables, I915_PDES);
1303 	struct drm_device *dev = vm->dev;
1304 	struct drm_i915_private *dev_priv = dev->dev_private;
1305 	struct i915_hw_ppgtt *ppgtt =
1306 				container_of(vm, struct i915_hw_ppgtt, base);
1307 	struct i915_page_table *pt;
1308 	const uint32_t start_save = start, length_save = length;
1309 	uint32_t pde, temp;
1310 	int ret;
1311 
1312 	WARN_ON(upper_32_bits(start));
1313 
1314 	bitmap_zero(new_page_tables, I915_PDES);
1315 
1316 	/* The allocation is done in two stages so that we can bail out with
1317 	 * minimal amount of pain. The first stage finds new page tables that
1318 	 * need allocation. The second stage marks use ptes within the page
1319 	 * tables.
1320 	 */
1321 	gen6_for_each_pde(pt, &ppgtt->pd, start, length, temp, pde) {
1322 		if (pt != ppgtt->scratch_pt) {
1323 			WARN_ON(bitmap_empty(pt->used_ptes, GEN6_PTES));
1324 			continue;
1325 		}
1326 
1327 		/* We've already allocated a page table */
1328 		WARN_ON(!bitmap_empty(pt->used_ptes, GEN6_PTES));
1329 
1330 		pt = alloc_pt_single(dev);
1331 		if (IS_ERR(pt)) {
1332 			ret = PTR_ERR(pt);
1333 			goto unwind_out;
1334 		}
1335 
1336 		gen6_initialize_pt(vm, pt);
1337 
1338 		ppgtt->pd.page_table[pde] = pt;
1339 		set_bit(pde, new_page_tables);
1340 		trace_i915_page_table_entry_alloc(vm, pde, start, GEN6_PDE_SHIFT);
1341 	}
1342 
1343 	start = start_save;
1344 	length = length_save;
1345 
1346 	gen6_for_each_pde(pt, &ppgtt->pd, start, length, temp, pde) {
1347 		DECLARE_BITMAP(tmp_bitmap, GEN6_PTES);
1348 
1349 		bitmap_zero(tmp_bitmap, GEN6_PTES);
1350 		bitmap_set(tmp_bitmap, gen6_pte_index(start),
1351 			   gen6_pte_count(start, length));
1352 
1353 		if (test_and_clear_bit(pde, new_page_tables))
1354 			gen6_write_pde(&ppgtt->pd, pde, pt);
1355 
1356 		trace_i915_page_table_entry_map(vm, pde, pt,
1357 					 gen6_pte_index(start),
1358 					 gen6_pte_count(start, length),
1359 					 GEN6_PTES);
1360 		bitmap_or(pt->used_ptes, tmp_bitmap, pt->used_ptes,
1361 				GEN6_PTES);
1362 	}
1363 
1364 	WARN_ON(!bitmap_empty(new_page_tables, I915_PDES));
1365 
1366 	/* Make sure write is complete before other code can use this page
1367 	 * table. Also require for WC mapped PTEs */
1368 	readl(dev_priv->gtt.gsm);
1369 
1370 	mark_tlbs_dirty(ppgtt);
1371 	return 0;
1372 
1373 unwind_out:
1374 	for_each_set_bit(pde, new_page_tables, I915_PDES) {
1375 		struct i915_page_table *pt = ppgtt->pd.page_table[pde];
1376 
1377 		ppgtt->pd.page_table[pde] = ppgtt->scratch_pt;
1378 		unmap_and_free_pt(pt, vm->dev);
1379 	}
1380 
1381 	mark_tlbs_dirty(ppgtt);
1382 	return ret;
1383 }
1384 
1385 static void gen6_ppgtt_cleanup(struct i915_address_space *vm)
1386 {
1387 	struct i915_hw_ppgtt *ppgtt =
1388 		container_of(vm, struct i915_hw_ppgtt, base);
1389 	struct i915_page_table *pt;
1390 	uint32_t pde;
1391 
1392 
1393 	drm_mm_remove_node(&ppgtt->node);
1394 
1395 	gen6_for_all_pdes(pt, ppgtt, pde) {
1396 		if (pt != ppgtt->scratch_pt)
1397 			unmap_and_free_pt(pt, ppgtt->base.dev);
1398 	}
1399 
1400 	unmap_and_free_pt(ppgtt->scratch_pt, ppgtt->base.dev);
1401 	unmap_and_free_pd(&ppgtt->pd, ppgtt->base.dev);
1402 }
1403 
1404 static int gen6_ppgtt_allocate_page_directories(struct i915_hw_ppgtt *ppgtt)
1405 {
1406 	struct drm_device *dev = ppgtt->base.dev;
1407 	struct drm_i915_private *dev_priv = dev->dev_private;
1408 	bool retried = false;
1409 	int ret;
1410 
1411 	/* PPGTT PDEs reside in the GGTT and consists of 512 entries. The
1412 	 * allocator works in address space sizes, so it's multiplied by page
1413 	 * size. We allocate at the top of the GTT to avoid fragmentation.
1414 	 */
1415 	BUG_ON(!drm_mm_initialized(&dev_priv->gtt.base.mm));
1416 	ppgtt->scratch_pt = alloc_pt_single(ppgtt->base.dev);
1417 	if (IS_ERR(ppgtt->scratch_pt))
1418 		return PTR_ERR(ppgtt->scratch_pt);
1419 
1420 	gen6_initialize_pt(&ppgtt->base, ppgtt->scratch_pt);
1421 
1422 alloc:
1423 	ret = drm_mm_insert_node_in_range_generic(&dev_priv->gtt.base.mm,
1424 						  &ppgtt->node, GEN6_PD_SIZE,
1425 						  GEN6_PD_ALIGN, 0,
1426 						  0, dev_priv->gtt.base.total,
1427 						  DRM_MM_TOPDOWN);
1428 	if (ret == -ENOSPC && !retried) {
1429 		ret = i915_gem_evict_something(dev, &dev_priv->gtt.base,
1430 					       GEN6_PD_SIZE, GEN6_PD_ALIGN,
1431 					       I915_CACHE_NONE,
1432 					       0, dev_priv->gtt.base.total,
1433 					       0);
1434 		if (ret)
1435 			goto err_out;
1436 
1437 		retried = true;
1438 		goto alloc;
1439 	}
1440 
1441 	if (ret)
1442 		goto err_out;
1443 
1444 
1445 	if (ppgtt->node.start < dev_priv->gtt.mappable_end)
1446 		DRM_DEBUG("Forced to use aperture for PDEs\n");
1447 
1448 	return 0;
1449 
1450 err_out:
1451 	unmap_and_free_pt(ppgtt->scratch_pt, ppgtt->base.dev);
1452 	return ret;
1453 }
1454 
1455 static int gen6_ppgtt_alloc(struct i915_hw_ppgtt *ppgtt)
1456 {
1457 	return gen6_ppgtt_allocate_page_directories(ppgtt);
1458 }
1459 
1460 static void gen6_scratch_va_range(struct i915_hw_ppgtt *ppgtt,
1461 				  uint64_t start, uint64_t length)
1462 {
1463 	struct i915_page_table *unused;
1464 	uint32_t pde, temp;
1465 
1466 	gen6_for_each_pde(unused, &ppgtt->pd, start, length, temp, pde)
1467 		ppgtt->pd.page_table[pde] = ppgtt->scratch_pt;
1468 }
1469 
1470 static int gen6_ppgtt_init(struct i915_hw_ppgtt *ppgtt)
1471 {
1472 	struct drm_device *dev = ppgtt->base.dev;
1473 	struct drm_i915_private *dev_priv = dev->dev_private;
1474 	int ret;
1475 
1476 	ppgtt->base.pte_encode = dev_priv->gtt.base.pte_encode;
1477 	if (IS_GEN6(dev)) {
1478 		ppgtt->switch_mm = gen6_mm_switch;
1479 	} else if (IS_HASWELL(dev)) {
1480 		ppgtt->switch_mm = hsw_mm_switch;
1481 	} else if (IS_GEN7(dev)) {
1482 		ppgtt->switch_mm = gen7_mm_switch;
1483 	} else
1484 		BUG();
1485 
1486 	if (intel_vgpu_active(dev))
1487 		ppgtt->switch_mm = vgpu_mm_switch;
1488 
1489 	ret = gen6_ppgtt_alloc(ppgtt);
1490 	if (ret)
1491 		return ret;
1492 
1493 	ppgtt->base.allocate_va_range = gen6_alloc_va_range;
1494 	ppgtt->base.clear_range = gen6_ppgtt_clear_range;
1495 	ppgtt->base.insert_entries = gen6_ppgtt_insert_entries;
1496 	ppgtt->base.unbind_vma = ppgtt_unbind_vma;
1497 	ppgtt->base.bind_vma = ppgtt_bind_vma;
1498 	ppgtt->base.cleanup = gen6_ppgtt_cleanup;
1499 	ppgtt->base.start = 0;
1500 	ppgtt->base.total = I915_PDES * GEN6_PTES * PAGE_SIZE;
1501 	ppgtt->debug_dump = gen6_dump_ppgtt;
1502 
1503 	ppgtt->pd.pd_offset =
1504 		ppgtt->node.start / PAGE_SIZE * sizeof(gen6_pte_t);
1505 
1506 	ppgtt->pd_addr = (gen6_pte_t __iomem *)dev_priv->gtt.gsm +
1507 		ppgtt->pd.pd_offset / sizeof(gen6_pte_t);
1508 
1509 	gen6_scratch_va_range(ppgtt, 0, ppgtt->base.total);
1510 
1511 	gen6_write_page_range(dev_priv, &ppgtt->pd, 0, ppgtt->base.total);
1512 
1513 	DRM_DEBUG_DRIVER("Allocated pde space (%lldM) at GTT entry: %llx\n",
1514 			 ppgtt->node.size >> 20,
1515 			 ppgtt->node.start / PAGE_SIZE);
1516 
1517 	DRM_DEBUG("Adding PPGTT at offset %x\n",
1518 		  ppgtt->pd.pd_offset << 10);
1519 
1520 	return 0;
1521 }
1522 
1523 static int __hw_ppgtt_init(struct drm_device *dev, struct i915_hw_ppgtt *ppgtt)
1524 {
1525 	struct drm_i915_private *dev_priv = dev->dev_private;
1526 
1527 	ppgtt->base.dev = dev;
1528 	ppgtt->base.scratch = dev_priv->gtt.base.scratch;
1529 
1530 	if (INTEL_INFO(dev)->gen < 8)
1531 		return gen6_ppgtt_init(ppgtt);
1532 	else
1533 		return gen8_ppgtt_init(ppgtt);
1534 }
1535 int i915_ppgtt_init(struct drm_device *dev, struct i915_hw_ppgtt *ppgtt)
1536 {
1537 	struct drm_i915_private *dev_priv = dev->dev_private;
1538 	int ret = 0;
1539 
1540 	ret = __hw_ppgtt_init(dev, ppgtt);
1541 	if (ret == 0) {
1542 		kref_init(&ppgtt->ref);
1543 		drm_mm_init(&ppgtt->base.mm, ppgtt->base.start,
1544 			    ppgtt->base.total);
1545 		i915_init_vm(dev_priv, &ppgtt->base);
1546 	}
1547 
1548 	return ret;
1549 }
1550 
1551 int i915_ppgtt_init_hw(struct drm_device *dev)
1552 {
1553 	struct drm_i915_private *dev_priv = dev->dev_private;
1554 	struct intel_engine_cs *ring;
1555 	struct i915_hw_ppgtt *ppgtt = dev_priv->mm.aliasing_ppgtt;
1556 	int i, ret = 0;
1557 
1558 	/* In the case of execlists, PPGTT is enabled by the context descriptor
1559 	 * and the PDPs are contained within the context itself.  We don't
1560 	 * need to do anything here. */
1561 	if (i915.enable_execlists)
1562 		return 0;
1563 
1564 	if (!USES_PPGTT(dev))
1565 		return 0;
1566 
1567 	if (IS_GEN6(dev))
1568 		gen6_ppgtt_enable(dev);
1569 	else if (IS_GEN7(dev))
1570 		gen7_ppgtt_enable(dev);
1571 	else if (INTEL_INFO(dev)->gen >= 8)
1572 		gen8_ppgtt_enable(dev);
1573 	else
1574 		MISSING_CASE(INTEL_INFO(dev)->gen);
1575 
1576 	if (ppgtt) {
1577 		for_each_ring(ring, dev_priv, i) {
1578 			ret = ppgtt->switch_mm(ppgtt, ring);
1579 			if (ret != 0)
1580 				return ret;
1581 		}
1582 	}
1583 
1584 	return ret;
1585 }
1586 struct i915_hw_ppgtt *
1587 i915_ppgtt_create(struct drm_device *dev, struct drm_i915_file_private *fpriv)
1588 {
1589 	struct i915_hw_ppgtt *ppgtt;
1590 	int ret;
1591 
1592 	ppgtt = kzalloc(sizeof(*ppgtt), GFP_KERNEL);
1593 	if (!ppgtt)
1594 		return ERR_PTR(-ENOMEM);
1595 
1596 	ret = i915_ppgtt_init(dev, ppgtt);
1597 	if (ret) {
1598 		kfree(ppgtt);
1599 		return ERR_PTR(ret);
1600 	}
1601 
1602 	ppgtt->file_priv = fpriv;
1603 
1604 	trace_i915_ppgtt_create(&ppgtt->base);
1605 
1606 	return ppgtt;
1607 }
1608 
1609 void  i915_ppgtt_release(struct kref *kref)
1610 {
1611 	struct i915_hw_ppgtt *ppgtt =
1612 		container_of(kref, struct i915_hw_ppgtt, ref);
1613 
1614 	trace_i915_ppgtt_release(&ppgtt->base);
1615 
1616 	/* vmas should already be unbound */
1617 	WARN_ON(!list_empty(&ppgtt->base.active_list));
1618 	WARN_ON(!list_empty(&ppgtt->base.inactive_list));
1619 
1620 	list_del(&ppgtt->base.global_link);
1621 	drm_mm_takedown(&ppgtt->base.mm);
1622 
1623 	ppgtt->base.cleanup(&ppgtt->base);
1624 	kfree(ppgtt);
1625 }
1626 
1627 extern int intel_iommu_gfx_mapped;
1628 /* Certain Gen5 chipsets require require idling the GPU before
1629  * unmapping anything from the GTT when VT-d is enabled.
1630  */
1631 static bool needs_idle_maps(struct drm_device *dev)
1632 {
1633 #ifdef CONFIG_INTEL_IOMMU
1634 	/* Query intel_iommu to see if we need the workaround. Presumably that
1635 	 * was loaded first.
1636 	 */
1637 	if (IS_GEN5(dev) && IS_MOBILE(dev) && intel_iommu_gfx_mapped)
1638 		return true;
1639 #endif
1640 	return false;
1641 }
1642 
1643 static bool do_idling(struct drm_i915_private *dev_priv)
1644 {
1645 	bool ret = dev_priv->mm.interruptible;
1646 
1647 	if (unlikely(dev_priv->gtt.do_idle_maps)) {
1648 		dev_priv->mm.interruptible = false;
1649 		if (i915_gpu_idle(dev_priv->dev)) {
1650 			DRM_ERROR("Couldn't idle GPU\n");
1651 			/* Wait a bit, in hopes it avoids the hang */
1652 			udelay(10);
1653 		}
1654 	}
1655 
1656 	return ret;
1657 }
1658 
1659 static void undo_idling(struct drm_i915_private *dev_priv, bool interruptible)
1660 {
1661 	if (unlikely(dev_priv->gtt.do_idle_maps))
1662 		dev_priv->mm.interruptible = interruptible;
1663 }
1664 
1665 void i915_check_and_clear_faults(struct drm_device *dev)
1666 {
1667 	struct drm_i915_private *dev_priv = dev->dev_private;
1668 	struct intel_engine_cs *ring;
1669 	int i;
1670 
1671 	if (INTEL_INFO(dev)->gen < 6)
1672 		return;
1673 
1674 	for_each_ring(ring, dev_priv, i) {
1675 		u32 fault_reg;
1676 		fault_reg = I915_READ(RING_FAULT_REG(ring));
1677 		if (fault_reg & RING_FAULT_VALID) {
1678 			DRM_DEBUG_DRIVER("Unexpected fault\n"
1679 					 "\tAddr: 0x%08lx\n"
1680 					 "\tAddress space: %s\n"
1681 					 "\tSource ID: %d\n"
1682 					 "\tType: %d\n",
1683 					 fault_reg & PAGE_MASK,
1684 					 fault_reg & RING_FAULT_GTTSEL_MASK ? "GGTT" : "PPGTT",
1685 					 RING_FAULT_SRCID(fault_reg),
1686 					 RING_FAULT_FAULT_TYPE(fault_reg));
1687 			I915_WRITE(RING_FAULT_REG(ring),
1688 				   fault_reg & ~RING_FAULT_VALID);
1689 		}
1690 	}
1691 	POSTING_READ(RING_FAULT_REG(&dev_priv->ring[RCS]));
1692 }
1693 
1694 static void i915_ggtt_flush(struct drm_i915_private *dev_priv)
1695 {
1696 	if (INTEL_INFO(dev_priv->dev)->gen < 6) {
1697 		intel_gtt_chipset_flush();
1698 	} else {
1699 		I915_WRITE(GFX_FLSH_CNTL_GEN6, GFX_FLSH_CNTL_EN);
1700 		POSTING_READ(GFX_FLSH_CNTL_GEN6);
1701 	}
1702 }
1703 
1704 void i915_gem_suspend_gtt_mappings(struct drm_device *dev)
1705 {
1706 	struct drm_i915_private *dev_priv = dev->dev_private;
1707 
1708 	/* Don't bother messing with faults pre GEN6 as we have little
1709 	 * documentation supporting that it's a good idea.
1710 	 */
1711 	if (INTEL_INFO(dev)->gen < 6)
1712 		return;
1713 
1714 	i915_check_and_clear_faults(dev);
1715 
1716 	dev_priv->gtt.base.clear_range(&dev_priv->gtt.base,
1717 				       dev_priv->gtt.base.start,
1718 				       dev_priv->gtt.base.total,
1719 				       true);
1720 
1721 	i915_ggtt_flush(dev_priv);
1722 }
1723 
1724 int i915_gem_gtt_prepare_object(struct drm_i915_gem_object *obj)
1725 {
1726 	if (!dma_map_sg(&obj->base.dev->pdev->dev,
1727 			obj->pages->sgl, obj->pages->nents,
1728 			PCI_DMA_BIDIRECTIONAL))
1729 		return -ENOSPC;
1730 
1731 	return 0;
1732 }
1733 
1734 static void gen8_set_pte(void __iomem *addr, gen8_pte_t pte)
1735 {
1736 #ifdef writeq
1737 	writeq(pte, addr);
1738 #else
1739 	iowrite32((u32)pte, addr);
1740 	iowrite32(pte >> 32, addr + 4);
1741 #endif
1742 }
1743 
1744 static void gen8_ggtt_insert_entries(struct i915_address_space *vm,
1745 				     struct sg_table *st,
1746 				     uint64_t start,
1747 				     enum i915_cache_level level, u32 unused)
1748 {
1749 	struct drm_i915_private *dev_priv = vm->dev->dev_private;
1750 	unsigned first_entry = start >> PAGE_SHIFT;
1751 	gen8_pte_t __iomem *gtt_entries =
1752 		(gen8_pte_t __iomem *)dev_priv->gtt.gsm + first_entry;
1753 	int i = 0;
1754 	struct sg_page_iter sg_iter;
1755 	dma_addr_t addr = 0; /* shut up gcc */
1756 
1757 	for_each_sg_page(st->sgl, &sg_iter, st->nents, 0) {
1758 		addr = sg_dma_address(sg_iter.sg) +
1759 			(sg_iter.sg_pgoffset << PAGE_SHIFT);
1760 		gen8_set_pte(&gtt_entries[i],
1761 			     gen8_pte_encode(addr, level, true));
1762 		i++;
1763 	}
1764 
1765 	/*
1766 	 * XXX: This serves as a posting read to make sure that the PTE has
1767 	 * actually been updated. There is some concern that even though
1768 	 * registers and PTEs are within the same BAR that they are potentially
1769 	 * of NUMA access patterns. Therefore, even with the way we assume
1770 	 * hardware should work, we must keep this posting read for paranoia.
1771 	 */
1772 	if (i != 0)
1773 		WARN_ON(readq(&gtt_entries[i-1])
1774 			!= gen8_pte_encode(addr, level, true));
1775 
1776 	/* This next bit makes the above posting read even more important. We
1777 	 * want to flush the TLBs only after we're certain all the PTE updates
1778 	 * have finished.
1779 	 */
1780 	I915_WRITE(GFX_FLSH_CNTL_GEN6, GFX_FLSH_CNTL_EN);
1781 	POSTING_READ(GFX_FLSH_CNTL_GEN6);
1782 }
1783 
1784 /*
1785  * Binds an object into the global gtt with the specified cache level. The object
1786  * will be accessible to the GPU via commands whose operands reference offsets
1787  * within the global GTT as well as accessible by the GPU through the GMADR
1788  * mapped BAR (dev_priv->mm.gtt->gtt).
1789  */
1790 static void gen6_ggtt_insert_entries(struct i915_address_space *vm,
1791 				     struct sg_table *st,
1792 				     uint64_t start,
1793 				     enum i915_cache_level level, u32 flags)
1794 {
1795 	struct drm_i915_private *dev_priv = vm->dev->dev_private;
1796 	unsigned first_entry = start >> PAGE_SHIFT;
1797 	gen6_pte_t __iomem *gtt_entries =
1798 		(gen6_pte_t __iomem *)dev_priv->gtt.gsm + first_entry;
1799 	int i = 0;
1800 	struct sg_page_iter sg_iter;
1801 	dma_addr_t addr = 0;
1802 
1803 	for_each_sg_page(st->sgl, &sg_iter, st->nents, 0) {
1804 		addr = sg_page_iter_dma_address(&sg_iter);
1805 		iowrite32(vm->pte_encode(addr, level, true, flags), &gtt_entries[i]);
1806 		i++;
1807 	}
1808 
1809 	/* XXX: This serves as a posting read to make sure that the PTE has
1810 	 * actually been updated. There is some concern that even though
1811 	 * registers and PTEs are within the same BAR that they are potentially
1812 	 * of NUMA access patterns. Therefore, even with the way we assume
1813 	 * hardware should work, we must keep this posting read for paranoia.
1814 	 */
1815 	if (i != 0) {
1816 		unsigned long gtt = readl(&gtt_entries[i-1]);
1817 		WARN_ON(gtt != vm->pte_encode(addr, level, true, flags));
1818 	}
1819 
1820 	/* This next bit makes the above posting read even more important. We
1821 	 * want to flush the TLBs only after we're certain all the PTE updates
1822 	 * have finished.
1823 	 */
1824 	I915_WRITE(GFX_FLSH_CNTL_GEN6, GFX_FLSH_CNTL_EN);
1825 	POSTING_READ(GFX_FLSH_CNTL_GEN6);
1826 }
1827 
1828 static void gen8_ggtt_clear_range(struct i915_address_space *vm,
1829 				  uint64_t start,
1830 				  uint64_t length,
1831 				  bool use_scratch)
1832 {
1833 	struct drm_i915_private *dev_priv = vm->dev->dev_private;
1834 	unsigned first_entry = start >> PAGE_SHIFT;
1835 	unsigned num_entries = length >> PAGE_SHIFT;
1836 	gen8_pte_t scratch_pte, __iomem *gtt_base =
1837 		(gen8_pte_t __iomem *) dev_priv->gtt.gsm + first_entry;
1838 	const int max_entries = gtt_total_entries(dev_priv->gtt) - first_entry;
1839 	int i;
1840 
1841 	if (WARN(num_entries > max_entries,
1842 		 "First entry = %d; Num entries = %d (max=%d)\n",
1843 		 first_entry, num_entries, max_entries))
1844 		num_entries = max_entries;
1845 
1846 	scratch_pte = gen8_pte_encode(vm->scratch.addr,
1847 				      I915_CACHE_LLC,
1848 				      use_scratch);
1849 	for (i = 0; i < num_entries; i++)
1850 		gen8_set_pte(&gtt_base[i], scratch_pte);
1851 	readl(gtt_base);
1852 }
1853 
1854 static void gen6_ggtt_clear_range(struct i915_address_space *vm,
1855 				  uint64_t start,
1856 				  uint64_t length,
1857 				  bool use_scratch)
1858 {
1859 	struct drm_i915_private *dev_priv = vm->dev->dev_private;
1860 	unsigned first_entry = start >> PAGE_SHIFT;
1861 	unsigned num_entries = length >> PAGE_SHIFT;
1862 	gen6_pte_t scratch_pte, __iomem *gtt_base =
1863 		(gen6_pte_t __iomem *) dev_priv->gtt.gsm + first_entry;
1864 	const int max_entries = gtt_total_entries(dev_priv->gtt) - first_entry;
1865 	int i;
1866 
1867 	if (WARN(num_entries > max_entries,
1868 		 "First entry = %d; Num entries = %d (max=%d)\n",
1869 		 first_entry, num_entries, max_entries))
1870 		num_entries = max_entries;
1871 
1872 	scratch_pte = vm->pte_encode(vm->scratch.addr, I915_CACHE_LLC, use_scratch, 0);
1873 
1874 	for (i = 0; i < num_entries; i++)
1875 		iowrite32(scratch_pte, &gtt_base[i]);
1876 	readl(gtt_base);
1877 }
1878 
1879 static void i915_ggtt_insert_entries(struct i915_address_space *vm,
1880 				     struct sg_table *pages,
1881 				     uint64_t start,
1882 				     enum i915_cache_level cache_level, u32 unused)
1883 {
1884 	unsigned int flags = (cache_level == I915_CACHE_NONE) ?
1885 		AGP_USER_MEMORY : AGP_USER_CACHED_MEMORY;
1886 
1887 	intel_gtt_insert_sg_entries(pages, start >> PAGE_SHIFT, flags);
1888 
1889 }
1890 
1891 static void i915_ggtt_clear_range(struct i915_address_space *vm,
1892 				  uint64_t start,
1893 				  uint64_t length,
1894 				  bool unused)
1895 {
1896 	unsigned first_entry = start >> PAGE_SHIFT;
1897 	unsigned num_entries = length >> PAGE_SHIFT;
1898 	intel_gtt_clear_range(first_entry, num_entries);
1899 }
1900 
1901 static int ggtt_bind_vma(struct i915_vma *vma,
1902 			 enum i915_cache_level cache_level,
1903 			 u32 flags)
1904 {
1905 	struct drm_device *dev = vma->vm->dev;
1906 	struct drm_i915_private *dev_priv = dev->dev_private;
1907 	struct drm_i915_gem_object *obj = vma->obj;
1908 	struct sg_table *pages = obj->pages;
1909 	u32 pte_flags = 0;
1910 	int ret;
1911 
1912 	ret = i915_get_ggtt_vma_pages(vma);
1913 	if (ret)
1914 		return ret;
1915 	pages = vma->ggtt_view.pages;
1916 
1917 	/* Currently applicable only to VLV */
1918 	if (obj->gt_ro)
1919 		pte_flags |= PTE_READ_ONLY;
1920 
1921 
1922 	if (!dev_priv->mm.aliasing_ppgtt || flags & GLOBAL_BIND) {
1923 		vma->vm->insert_entries(vma->vm, pages,
1924 					vma->node.start,
1925 					cache_level, pte_flags);
1926 
1927 		/* Note the inconsistency here is due to absence of the
1928 		 * aliasing ppgtt on gen4 and earlier. Though we always
1929 		 * request PIN_USER for execbuffer (translated to LOCAL_BIND),
1930 		 * without the appgtt, we cannot honour that request and so
1931 		 * must substitute it with a global binding. Since we do this
1932 		 * behind the upper layers back, we need to explicitly set
1933 		 * the bound flag ourselves.
1934 		 */
1935 		vma->bound |= GLOBAL_BIND;
1936 
1937 	}
1938 
1939 	if (dev_priv->mm.aliasing_ppgtt && flags & LOCAL_BIND) {
1940 		struct i915_hw_ppgtt *appgtt = dev_priv->mm.aliasing_ppgtt;
1941 		appgtt->base.insert_entries(&appgtt->base, pages,
1942 					    vma->node.start,
1943 					    cache_level, pte_flags);
1944 	}
1945 
1946 	return 0;
1947 }
1948 
1949 static void ggtt_unbind_vma(struct i915_vma *vma)
1950 {
1951 	struct drm_device *dev = vma->vm->dev;
1952 	struct drm_i915_private *dev_priv = dev->dev_private;
1953 	struct drm_i915_gem_object *obj = vma->obj;
1954 	const uint64_t size = min_t(uint64_t,
1955 				    obj->base.size,
1956 				    vma->node.size);
1957 
1958 	if (vma->bound & GLOBAL_BIND) {
1959 		vma->vm->clear_range(vma->vm,
1960 				     vma->node.start,
1961 				     size,
1962 				     true);
1963 	}
1964 
1965 	if (dev_priv->mm.aliasing_ppgtt && vma->bound & LOCAL_BIND) {
1966 		struct i915_hw_ppgtt *appgtt = dev_priv->mm.aliasing_ppgtt;
1967 
1968 		appgtt->base.clear_range(&appgtt->base,
1969 					 vma->node.start,
1970 					 size,
1971 					 true);
1972 	}
1973 }
1974 
1975 void i915_gem_gtt_finish_object(struct drm_i915_gem_object *obj)
1976 {
1977 	struct drm_device *dev = obj->base.dev;
1978 	struct drm_i915_private *dev_priv = dev->dev_private;
1979 	bool interruptible;
1980 
1981 	interruptible = do_idling(dev_priv);
1982 
1983 	dma_unmap_sg(&dev->pdev->dev, obj->pages->sgl, obj->pages->nents,
1984 		     PCI_DMA_BIDIRECTIONAL);
1985 
1986 	undo_idling(dev_priv, interruptible);
1987 }
1988 
1989 static void i915_gtt_color_adjust(struct drm_mm_node *node,
1990 				  unsigned long color,
1991 				  u64 *start,
1992 				  u64 *end)
1993 {
1994 	if (node->color != color)
1995 		*start += 4096;
1996 
1997 	if (!list_empty(&node->node_list)) {
1998 		node = list_entry(node->node_list.next,
1999 				  struct drm_mm_node,
2000 				  node_list);
2001 		if (node->allocated && node->color != color)
2002 			*end -= 4096;
2003 	}
2004 }
2005 
2006 static int i915_gem_setup_global_gtt(struct drm_device *dev,
2007 				     unsigned long start,
2008 				     unsigned long mappable_end,
2009 				     unsigned long end)
2010 {
2011 	/* Let GEM Manage all of the aperture.
2012 	 *
2013 	 * However, leave one page at the end still bound to the scratch page.
2014 	 * There are a number of places where the hardware apparently prefetches
2015 	 * past the end of the object, and we've seen multiple hangs with the
2016 	 * GPU head pointer stuck in a batchbuffer bound at the last page of the
2017 	 * aperture.  One page should be enough to keep any prefetching inside
2018 	 * of the aperture.
2019 	 */
2020 	struct drm_i915_private *dev_priv = dev->dev_private;
2021 	struct i915_address_space *ggtt_vm = &dev_priv->gtt.base;
2022 	struct drm_mm_node *entry;
2023 	struct drm_i915_gem_object *obj;
2024 	unsigned long hole_start, hole_end;
2025 	int ret;
2026 
2027 	BUG_ON(mappable_end > end);
2028 
2029 	/* Subtract the guard page ... */
2030 	drm_mm_init(&ggtt_vm->mm, start, end - start - PAGE_SIZE);
2031 
2032 	dev_priv->gtt.base.start = start;
2033 	dev_priv->gtt.base.total = end - start;
2034 
2035 	if (intel_vgpu_active(dev)) {
2036 		ret = intel_vgt_balloon(dev);
2037 		if (ret)
2038 			return ret;
2039 	}
2040 
2041 	if (!HAS_LLC(dev))
2042 		dev_priv->gtt.base.mm.color_adjust = i915_gtt_color_adjust;
2043 
2044 	/* Mark any preallocated objects as occupied */
2045 	list_for_each_entry(obj, &dev_priv->mm.bound_list, global_list) {
2046 		struct i915_vma *vma = i915_gem_obj_to_vma(obj, ggtt_vm);
2047 
2048 		DRM_DEBUG_KMS("reserving preallocated space: %lx + %zx\n",
2049 			      i915_gem_obj_ggtt_offset(obj), obj->base.size);
2050 
2051 		WARN_ON(i915_gem_obj_ggtt_bound(obj));
2052 		ret = drm_mm_reserve_node(&ggtt_vm->mm, &vma->node);
2053 		if (ret) {
2054 			DRM_DEBUG_KMS("Reservation failed: %i\n", ret);
2055 			return ret;
2056 		}
2057 		vma->bound |= GLOBAL_BIND;
2058 	}
2059 
2060 	/* Clear any non-preallocated blocks */
2061 	drm_mm_for_each_hole(entry, &ggtt_vm->mm, hole_start, hole_end) {
2062 		DRM_DEBUG_KMS("clearing unused GTT space: [%lx, %lx]\n",
2063 			      hole_start, hole_end);
2064 		ggtt_vm->clear_range(ggtt_vm, hole_start,
2065 				     hole_end - hole_start, true);
2066 	}
2067 
2068 	/* And finally clear the reserved guard page */
2069 	ggtt_vm->clear_range(ggtt_vm, end - PAGE_SIZE, PAGE_SIZE, true);
2070 
2071 	if (USES_PPGTT(dev) && !USES_FULL_PPGTT(dev)) {
2072 		struct i915_hw_ppgtt *ppgtt;
2073 
2074 		ppgtt = kzalloc(sizeof(*ppgtt), GFP_KERNEL);
2075 		if (!ppgtt)
2076 			return -ENOMEM;
2077 
2078 		ret = __hw_ppgtt_init(dev, ppgtt);
2079 		if (ret) {
2080 			ppgtt->base.cleanup(&ppgtt->base);
2081 			kfree(ppgtt);
2082 			return ret;
2083 		}
2084 
2085 		if (ppgtt->base.allocate_va_range)
2086 			ret = ppgtt->base.allocate_va_range(&ppgtt->base, 0,
2087 							    ppgtt->base.total);
2088 		if (ret) {
2089 			ppgtt->base.cleanup(&ppgtt->base);
2090 			kfree(ppgtt);
2091 			return ret;
2092 		}
2093 
2094 		ppgtt->base.clear_range(&ppgtt->base,
2095 					ppgtt->base.start,
2096 					ppgtt->base.total,
2097 					true);
2098 
2099 		dev_priv->mm.aliasing_ppgtt = ppgtt;
2100 	}
2101 
2102 	return 0;
2103 }
2104 
2105 void i915_gem_init_global_gtt(struct drm_device *dev)
2106 {
2107 	struct drm_i915_private *dev_priv = dev->dev_private;
2108 	unsigned long gtt_size, mappable_size;
2109 
2110 	gtt_size = dev_priv->gtt.base.total;
2111 	mappable_size = dev_priv->gtt.mappable_end;
2112 
2113 	i915_gem_setup_global_gtt(dev, 0, mappable_size, gtt_size);
2114 }
2115 
2116 void i915_global_gtt_cleanup(struct drm_device *dev)
2117 {
2118 	struct drm_i915_private *dev_priv = dev->dev_private;
2119 	struct i915_address_space *vm = &dev_priv->gtt.base;
2120 
2121 	if (dev_priv->mm.aliasing_ppgtt) {
2122 		struct i915_hw_ppgtt *ppgtt = dev_priv->mm.aliasing_ppgtt;
2123 
2124 		ppgtt->base.cleanup(&ppgtt->base);
2125 	}
2126 
2127 	if (drm_mm_initialized(&vm->mm)) {
2128 		if (intel_vgpu_active(dev))
2129 			intel_vgt_deballoon();
2130 
2131 		drm_mm_takedown(&vm->mm);
2132 		list_del(&vm->global_link);
2133 	}
2134 
2135 	vm->cleanup(vm);
2136 }
2137 
2138 static int setup_scratch_page(struct drm_device *dev)
2139 {
2140 	struct drm_i915_private *dev_priv = dev->dev_private;
2141 	struct page *page;
2142 	dma_addr_t dma_addr;
2143 
2144 	page = alloc_page(GFP_KERNEL | GFP_DMA32 | __GFP_ZERO);
2145 	if (page == NULL)
2146 		return -ENOMEM;
2147 	set_pages_uc(page, 1);
2148 
2149 #ifdef CONFIG_INTEL_IOMMU
2150 	dma_addr = pci_map_page(dev->pdev, page, 0, PAGE_SIZE,
2151 				PCI_DMA_BIDIRECTIONAL);
2152 	if (pci_dma_mapping_error(dev->pdev, dma_addr))
2153 		return -EINVAL;
2154 #else
2155 	dma_addr = page_to_phys(page);
2156 #endif
2157 	dev_priv->gtt.base.scratch.page = page;
2158 	dev_priv->gtt.base.scratch.addr = dma_addr;
2159 
2160 	return 0;
2161 }
2162 
2163 static void teardown_scratch_page(struct drm_device *dev)
2164 {
2165 	struct drm_i915_private *dev_priv = dev->dev_private;
2166 	struct page *page = dev_priv->gtt.base.scratch.page;
2167 
2168 	set_pages_wb(page, 1);
2169 	pci_unmap_page(dev->pdev, dev_priv->gtt.base.scratch.addr,
2170 		       PAGE_SIZE, PCI_DMA_BIDIRECTIONAL);
2171 	__free_page(page);
2172 }
2173 
2174 static unsigned int gen6_get_total_gtt_size(u16 snb_gmch_ctl)
2175 {
2176 	snb_gmch_ctl >>= SNB_GMCH_GGMS_SHIFT;
2177 	snb_gmch_ctl &= SNB_GMCH_GGMS_MASK;
2178 	return snb_gmch_ctl << 20;
2179 }
2180 
2181 static unsigned int gen8_get_total_gtt_size(u16 bdw_gmch_ctl)
2182 {
2183 	bdw_gmch_ctl >>= BDW_GMCH_GGMS_SHIFT;
2184 	bdw_gmch_ctl &= BDW_GMCH_GGMS_MASK;
2185 	if (bdw_gmch_ctl)
2186 		bdw_gmch_ctl = 1 << bdw_gmch_ctl;
2187 
2188 #ifdef CONFIG_X86_32
2189 	/* Limit 32b platforms to a 2GB GGTT: 4 << 20 / pte size * PAGE_SIZE */
2190 	if (bdw_gmch_ctl > 4)
2191 		bdw_gmch_ctl = 4;
2192 #endif
2193 
2194 	return bdw_gmch_ctl << 20;
2195 }
2196 
2197 static unsigned int chv_get_total_gtt_size(u16 gmch_ctrl)
2198 {
2199 	gmch_ctrl >>= SNB_GMCH_GGMS_SHIFT;
2200 	gmch_ctrl &= SNB_GMCH_GGMS_MASK;
2201 
2202 	if (gmch_ctrl)
2203 		return 1 << (20 + gmch_ctrl);
2204 
2205 	return 0;
2206 }
2207 
2208 static size_t gen6_get_stolen_size(u16 snb_gmch_ctl)
2209 {
2210 	snb_gmch_ctl >>= SNB_GMCH_GMS_SHIFT;
2211 	snb_gmch_ctl &= SNB_GMCH_GMS_MASK;
2212 	return snb_gmch_ctl << 25; /* 32 MB units */
2213 }
2214 
2215 static size_t gen8_get_stolen_size(u16 bdw_gmch_ctl)
2216 {
2217 	bdw_gmch_ctl >>= BDW_GMCH_GMS_SHIFT;
2218 	bdw_gmch_ctl &= BDW_GMCH_GMS_MASK;
2219 	return bdw_gmch_ctl << 25; /* 32 MB units */
2220 }
2221 
2222 static size_t chv_get_stolen_size(u16 gmch_ctrl)
2223 {
2224 	gmch_ctrl >>= SNB_GMCH_GMS_SHIFT;
2225 	gmch_ctrl &= SNB_GMCH_GMS_MASK;
2226 
2227 	/*
2228 	 * 0x0  to 0x10: 32MB increments starting at 0MB
2229 	 * 0x11 to 0x16: 4MB increments starting at 8MB
2230 	 * 0x17 to 0x1d: 4MB increments start at 36MB
2231 	 */
2232 	if (gmch_ctrl < 0x11)
2233 		return gmch_ctrl << 25;
2234 	else if (gmch_ctrl < 0x17)
2235 		return (gmch_ctrl - 0x11 + 2) << 22;
2236 	else
2237 		return (gmch_ctrl - 0x17 + 9) << 22;
2238 }
2239 
2240 static size_t gen9_get_stolen_size(u16 gen9_gmch_ctl)
2241 {
2242 	gen9_gmch_ctl >>= BDW_GMCH_GMS_SHIFT;
2243 	gen9_gmch_ctl &= BDW_GMCH_GMS_MASK;
2244 
2245 	if (gen9_gmch_ctl < 0xf0)
2246 		return gen9_gmch_ctl << 25; /* 32 MB units */
2247 	else
2248 		/* 4MB increments starting at 0xf0 for 4MB */
2249 		return (gen9_gmch_ctl - 0xf0 + 1) << 22;
2250 }
2251 
2252 static int ggtt_probe_common(struct drm_device *dev,
2253 			     size_t gtt_size)
2254 {
2255 	struct drm_i915_private *dev_priv = dev->dev_private;
2256 	phys_addr_t gtt_phys_addr;
2257 	int ret;
2258 
2259 	/* For Modern GENs the PTEs and register space are split in the BAR */
2260 	gtt_phys_addr = pci_resource_start(dev->pdev, 0) +
2261 		(pci_resource_len(dev->pdev, 0) / 2);
2262 
2263 	/*
2264 	 * On BXT writes larger than 64 bit to the GTT pagetable range will be
2265 	 * dropped. For WC mappings in general we have 64 byte burst writes
2266 	 * when the WC buffer is flushed, so we can't use it, but have to
2267 	 * resort to an uncached mapping. The WC issue is easily caught by the
2268 	 * readback check when writing GTT PTE entries.
2269 	 */
2270 	if (IS_BROXTON(dev))
2271 		dev_priv->gtt.gsm = ioremap_nocache(gtt_phys_addr, gtt_size);
2272 	else
2273 		dev_priv->gtt.gsm = ioremap_wc(gtt_phys_addr, gtt_size);
2274 	if (!dev_priv->gtt.gsm) {
2275 		DRM_ERROR("Failed to map the gtt page table\n");
2276 		return -ENOMEM;
2277 	}
2278 
2279 	ret = setup_scratch_page(dev);
2280 	if (ret) {
2281 		DRM_ERROR("Scratch setup failed\n");
2282 		/* iounmap will also get called at remove, but meh */
2283 		iounmap(dev_priv->gtt.gsm);
2284 	}
2285 
2286 	return ret;
2287 }
2288 
2289 /* The GGTT and PPGTT need a private PPAT setup in order to handle cacheability
2290  * bits. When using advanced contexts each context stores its own PAT, but
2291  * writing this data shouldn't be harmful even in those cases. */
2292 static void bdw_setup_private_ppat(struct drm_i915_private *dev_priv)
2293 {
2294 	uint64_t pat;
2295 
2296 	pat = GEN8_PPAT(0, GEN8_PPAT_WB | GEN8_PPAT_LLC)     | /* for normal objects, no eLLC */
2297 	      GEN8_PPAT(1, GEN8_PPAT_WC | GEN8_PPAT_LLCELLC) | /* for something pointing to ptes? */
2298 	      GEN8_PPAT(2, GEN8_PPAT_WT | GEN8_PPAT_LLCELLC) | /* for scanout with eLLC */
2299 	      GEN8_PPAT(3, GEN8_PPAT_UC)                     | /* Uncached objects, mostly for scanout */
2300 	      GEN8_PPAT(4, GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(0)) |
2301 	      GEN8_PPAT(5, GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(1)) |
2302 	      GEN8_PPAT(6, GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(2)) |
2303 	      GEN8_PPAT(7, GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(3));
2304 
2305 	if (!USES_PPGTT(dev_priv->dev))
2306 		/* Spec: "For GGTT, there is NO pat_sel[2:0] from the entry,
2307 		 * so RTL will always use the value corresponding to
2308 		 * pat_sel = 000".
2309 		 * So let's disable cache for GGTT to avoid screen corruptions.
2310 		 * MOCS still can be used though.
2311 		 * - System agent ggtt writes (i.e. cpu gtt mmaps) already work
2312 		 * before this patch, i.e. the same uncached + snooping access
2313 		 * like on gen6/7 seems to be in effect.
2314 		 * - So this just fixes blitter/render access. Again it looks
2315 		 * like it's not just uncached access, but uncached + snooping.
2316 		 * So we can still hold onto all our assumptions wrt cpu
2317 		 * clflushing on LLC machines.
2318 		 */
2319 		pat = GEN8_PPAT(0, GEN8_PPAT_UC);
2320 
2321 	/* XXX: spec defines this as 2 distinct registers. It's unclear if a 64b
2322 	 * write would work. */
2323 	I915_WRITE(GEN8_PRIVATE_PAT, pat);
2324 	I915_WRITE(GEN8_PRIVATE_PAT + 4, pat >> 32);
2325 }
2326 
2327 static void chv_setup_private_ppat(struct drm_i915_private *dev_priv)
2328 {
2329 	uint64_t pat;
2330 
2331 	/*
2332 	 * Map WB on BDW to snooped on CHV.
2333 	 *
2334 	 * Only the snoop bit has meaning for CHV, the rest is
2335 	 * ignored.
2336 	 *
2337 	 * The hardware will never snoop for certain types of accesses:
2338 	 * - CPU GTT (GMADR->GGTT->no snoop->memory)
2339 	 * - PPGTT page tables
2340 	 * - some other special cycles
2341 	 *
2342 	 * As with BDW, we also need to consider the following for GT accesses:
2343 	 * "For GGTT, there is NO pat_sel[2:0] from the entry,
2344 	 * so RTL will always use the value corresponding to
2345 	 * pat_sel = 000".
2346 	 * Which means we must set the snoop bit in PAT entry 0
2347 	 * in order to keep the global status page working.
2348 	 */
2349 	pat = GEN8_PPAT(0, CHV_PPAT_SNOOP) |
2350 	      GEN8_PPAT(1, 0) |
2351 	      GEN8_PPAT(2, 0) |
2352 	      GEN8_PPAT(3, 0) |
2353 	      GEN8_PPAT(4, CHV_PPAT_SNOOP) |
2354 	      GEN8_PPAT(5, CHV_PPAT_SNOOP) |
2355 	      GEN8_PPAT(6, CHV_PPAT_SNOOP) |
2356 	      GEN8_PPAT(7, CHV_PPAT_SNOOP);
2357 
2358 	I915_WRITE(GEN8_PRIVATE_PAT, pat);
2359 	I915_WRITE(GEN8_PRIVATE_PAT + 4, pat >> 32);
2360 }
2361 
2362 static int gen8_gmch_probe(struct drm_device *dev,
2363 			   size_t *gtt_total,
2364 			   size_t *stolen,
2365 			   phys_addr_t *mappable_base,
2366 			   unsigned long *mappable_end)
2367 {
2368 	struct drm_i915_private *dev_priv = dev->dev_private;
2369 	unsigned int gtt_size;
2370 	u16 snb_gmch_ctl;
2371 	int ret;
2372 
2373 	/* TODO: We're not aware of mappable constraints on gen8 yet */
2374 	*mappable_base = pci_resource_start(dev->pdev, 2);
2375 	*mappable_end = pci_resource_len(dev->pdev, 2);
2376 
2377 	if (!pci_set_dma_mask(dev->pdev, DMA_BIT_MASK(39)))
2378 		pci_set_consistent_dma_mask(dev->pdev, DMA_BIT_MASK(39));
2379 
2380 	pci_read_config_word(dev->pdev, SNB_GMCH_CTRL, &snb_gmch_ctl);
2381 
2382 	if (INTEL_INFO(dev)->gen >= 9) {
2383 		*stolen = gen9_get_stolen_size(snb_gmch_ctl);
2384 		gtt_size = gen8_get_total_gtt_size(snb_gmch_ctl);
2385 	} else if (IS_CHERRYVIEW(dev)) {
2386 		*stolen = chv_get_stolen_size(snb_gmch_ctl);
2387 		gtt_size = chv_get_total_gtt_size(snb_gmch_ctl);
2388 	} else {
2389 		*stolen = gen8_get_stolen_size(snb_gmch_ctl);
2390 		gtt_size = gen8_get_total_gtt_size(snb_gmch_ctl);
2391 	}
2392 
2393 	*gtt_total = (gtt_size / sizeof(gen8_pte_t)) << PAGE_SHIFT;
2394 
2395 	if (IS_CHERRYVIEW(dev) || IS_BROXTON(dev))
2396 		chv_setup_private_ppat(dev_priv);
2397 	else
2398 		bdw_setup_private_ppat(dev_priv);
2399 
2400 	ret = ggtt_probe_common(dev, gtt_size);
2401 
2402 	dev_priv->gtt.base.clear_range = gen8_ggtt_clear_range;
2403 	dev_priv->gtt.base.insert_entries = gen8_ggtt_insert_entries;
2404 	dev_priv->gtt.base.bind_vma = ggtt_bind_vma;
2405 	dev_priv->gtt.base.unbind_vma = ggtt_unbind_vma;
2406 
2407 	return ret;
2408 }
2409 
2410 static int gen6_gmch_probe(struct drm_device *dev,
2411 			   size_t *gtt_total,
2412 			   size_t *stolen,
2413 			   phys_addr_t *mappable_base,
2414 			   unsigned long *mappable_end)
2415 {
2416 	struct drm_i915_private *dev_priv = dev->dev_private;
2417 	unsigned int gtt_size;
2418 	u16 snb_gmch_ctl;
2419 	int ret;
2420 
2421 	*mappable_base = pci_resource_start(dev->pdev, 2);
2422 	*mappable_end = pci_resource_len(dev->pdev, 2);
2423 
2424 	/* 64/512MB is the current min/max we actually know of, but this is just
2425 	 * a coarse sanity check.
2426 	 */
2427 	if ((*mappable_end < (64<<20) || (*mappable_end > (512<<20)))) {
2428 		DRM_ERROR("Unknown GMADR size (%lx)\n",
2429 			  dev_priv->gtt.mappable_end);
2430 		return -ENXIO;
2431 	}
2432 
2433 	if (!pci_set_dma_mask(dev->pdev, DMA_BIT_MASK(40)))
2434 		pci_set_consistent_dma_mask(dev->pdev, DMA_BIT_MASK(40));
2435 	pci_read_config_word(dev->pdev, SNB_GMCH_CTRL, &snb_gmch_ctl);
2436 
2437 	*stolen = gen6_get_stolen_size(snb_gmch_ctl);
2438 
2439 	gtt_size = gen6_get_total_gtt_size(snb_gmch_ctl);
2440 	*gtt_total = (gtt_size / sizeof(gen6_pte_t)) << PAGE_SHIFT;
2441 
2442 	ret = ggtt_probe_common(dev, gtt_size);
2443 
2444 	dev_priv->gtt.base.clear_range = gen6_ggtt_clear_range;
2445 	dev_priv->gtt.base.insert_entries = gen6_ggtt_insert_entries;
2446 	dev_priv->gtt.base.bind_vma = ggtt_bind_vma;
2447 	dev_priv->gtt.base.unbind_vma = ggtt_unbind_vma;
2448 
2449 	return ret;
2450 }
2451 
2452 static void gen6_gmch_remove(struct i915_address_space *vm)
2453 {
2454 
2455 	struct i915_gtt *gtt = container_of(vm, struct i915_gtt, base);
2456 
2457 	iounmap(gtt->gsm);
2458 	teardown_scratch_page(vm->dev);
2459 }
2460 
2461 static int i915_gmch_probe(struct drm_device *dev,
2462 			   size_t *gtt_total,
2463 			   size_t *stolen,
2464 			   phys_addr_t *mappable_base,
2465 			   unsigned long *mappable_end)
2466 {
2467 	struct drm_i915_private *dev_priv = dev->dev_private;
2468 	int ret;
2469 
2470 	ret = intel_gmch_probe(dev_priv->bridge_dev, dev_priv->dev->pdev, NULL);
2471 	if (!ret) {
2472 		DRM_ERROR("failed to set up gmch\n");
2473 		return -EIO;
2474 	}
2475 
2476 	intel_gtt_get(gtt_total, stolen, mappable_base, mappable_end);
2477 
2478 	dev_priv->gtt.do_idle_maps = needs_idle_maps(dev_priv->dev);
2479 	dev_priv->gtt.base.insert_entries = i915_ggtt_insert_entries;
2480 	dev_priv->gtt.base.clear_range = i915_ggtt_clear_range;
2481 	dev_priv->gtt.base.bind_vma = ggtt_bind_vma;
2482 	dev_priv->gtt.base.unbind_vma = ggtt_unbind_vma;
2483 
2484 	if (unlikely(dev_priv->gtt.do_idle_maps))
2485 		DRM_INFO("applying Ironlake quirks for intel_iommu\n");
2486 
2487 	return 0;
2488 }
2489 
2490 static void i915_gmch_remove(struct i915_address_space *vm)
2491 {
2492 	intel_gmch_remove();
2493 }
2494 
2495 int i915_gem_gtt_init(struct drm_device *dev)
2496 {
2497 	struct drm_i915_private *dev_priv = dev->dev_private;
2498 	struct i915_gtt *gtt = &dev_priv->gtt;
2499 	int ret;
2500 
2501 	if (INTEL_INFO(dev)->gen <= 5) {
2502 		gtt->gtt_probe = i915_gmch_probe;
2503 		gtt->base.cleanup = i915_gmch_remove;
2504 	} else if (INTEL_INFO(dev)->gen < 8) {
2505 		gtt->gtt_probe = gen6_gmch_probe;
2506 		gtt->base.cleanup = gen6_gmch_remove;
2507 		if (IS_HASWELL(dev) && dev_priv->ellc_size)
2508 			gtt->base.pte_encode = iris_pte_encode;
2509 		else if (IS_HASWELL(dev))
2510 			gtt->base.pte_encode = hsw_pte_encode;
2511 		else if (IS_VALLEYVIEW(dev))
2512 			gtt->base.pte_encode = byt_pte_encode;
2513 		else if (INTEL_INFO(dev)->gen >= 7)
2514 			gtt->base.pte_encode = ivb_pte_encode;
2515 		else
2516 			gtt->base.pte_encode = snb_pte_encode;
2517 	} else {
2518 		dev_priv->gtt.gtt_probe = gen8_gmch_probe;
2519 		dev_priv->gtt.base.cleanup = gen6_gmch_remove;
2520 	}
2521 
2522 	ret = gtt->gtt_probe(dev, &gtt->base.total, &gtt->stolen_size,
2523 			     &gtt->mappable_base, &gtt->mappable_end);
2524 	if (ret)
2525 		return ret;
2526 
2527 	gtt->base.dev = dev;
2528 
2529 	/* GMADR is the PCI mmio aperture into the global GTT. */
2530 	DRM_INFO("Memory usable by graphics device = %zdM\n",
2531 		 gtt->base.total >> 20);
2532 	DRM_DEBUG_DRIVER("GMADR size = %ldM\n", gtt->mappable_end >> 20);
2533 	DRM_DEBUG_DRIVER("GTT stolen size = %zdM\n", gtt->stolen_size >> 20);
2534 #ifdef CONFIG_INTEL_IOMMU
2535 	if (intel_iommu_gfx_mapped)
2536 		DRM_INFO("VT-d active for gfx access\n");
2537 #endif
2538 	/*
2539 	 * i915.enable_ppgtt is read-only, so do an early pass to validate the
2540 	 * user's requested state against the hardware/driver capabilities.  We
2541 	 * do this now so that we can print out any log messages once rather
2542 	 * than every time we check intel_enable_ppgtt().
2543 	 */
2544 	i915.enable_ppgtt = sanitize_enable_ppgtt(dev, i915.enable_ppgtt);
2545 	DRM_DEBUG_DRIVER("ppgtt mode: %i\n", i915.enable_ppgtt);
2546 
2547 	return 0;
2548 }
2549 
2550 void i915_gem_restore_gtt_mappings(struct drm_device *dev)
2551 {
2552 	struct drm_i915_private *dev_priv = dev->dev_private;
2553 	struct drm_i915_gem_object *obj;
2554 	struct i915_address_space *vm;
2555 	struct i915_vma *vma;
2556 	bool flush;
2557 
2558 	i915_check_and_clear_faults(dev);
2559 
2560 	/* First fill our portion of the GTT with scratch pages */
2561 	dev_priv->gtt.base.clear_range(&dev_priv->gtt.base,
2562 				       dev_priv->gtt.base.start,
2563 				       dev_priv->gtt.base.total,
2564 				       true);
2565 
2566 	/* Cache flush objects bound into GGTT and rebind them. */
2567 	vm = &dev_priv->gtt.base;
2568 	list_for_each_entry(obj, &dev_priv->mm.bound_list, global_list) {
2569 		flush = false;
2570 		list_for_each_entry(vma, &obj->vma_list, vma_link) {
2571 			if (vma->vm != vm)
2572 				continue;
2573 
2574 			WARN_ON(i915_vma_bind(vma, obj->cache_level,
2575 					      PIN_UPDATE));
2576 
2577 			flush = true;
2578 		}
2579 
2580 		if (flush)
2581 			i915_gem_clflush_object(obj, obj->pin_display);
2582 	}
2583 
2584 	if (INTEL_INFO(dev)->gen >= 8) {
2585 		if (IS_CHERRYVIEW(dev) || IS_BROXTON(dev))
2586 			chv_setup_private_ppat(dev_priv);
2587 		else
2588 			bdw_setup_private_ppat(dev_priv);
2589 
2590 		return;
2591 	}
2592 
2593 	if (USES_PPGTT(dev)) {
2594 		list_for_each_entry(vm, &dev_priv->vm_list, global_link) {
2595 			/* TODO: Perhaps it shouldn't be gen6 specific */
2596 
2597 			struct i915_hw_ppgtt *ppgtt =
2598 					container_of(vm, struct i915_hw_ppgtt,
2599 						     base);
2600 
2601 			if (i915_is_ggtt(vm))
2602 				ppgtt = dev_priv->mm.aliasing_ppgtt;
2603 
2604 			gen6_write_page_range(dev_priv, &ppgtt->pd,
2605 					      0, ppgtt->base.total);
2606 		}
2607 	}
2608 
2609 	i915_ggtt_flush(dev_priv);
2610 }
2611 
2612 static struct i915_vma *
2613 __i915_gem_vma_create(struct drm_i915_gem_object *obj,
2614 		      struct i915_address_space *vm,
2615 		      const struct i915_ggtt_view *ggtt_view)
2616 {
2617 	struct i915_vma *vma;
2618 
2619 	if (WARN_ON(i915_is_ggtt(vm) != !!ggtt_view))
2620 		return ERR_PTR(-EINVAL);
2621 
2622 	vma = kmem_cache_zalloc(to_i915(obj->base.dev)->vmas, GFP_KERNEL);
2623 	if (vma == NULL)
2624 		return ERR_PTR(-ENOMEM);
2625 
2626 	INIT_LIST_HEAD(&vma->vma_link);
2627 	INIT_LIST_HEAD(&vma->mm_list);
2628 	INIT_LIST_HEAD(&vma->exec_list);
2629 	vma->vm = vm;
2630 	vma->obj = obj;
2631 
2632 	if (i915_is_ggtt(vm))
2633 		vma->ggtt_view = *ggtt_view;
2634 
2635 	list_add_tail(&vma->vma_link, &obj->vma_list);
2636 	if (!i915_is_ggtt(vm))
2637 		i915_ppgtt_get(i915_vm_to_ppgtt(vm));
2638 
2639 	return vma;
2640 }
2641 
2642 struct i915_vma *
2643 i915_gem_obj_lookup_or_create_vma(struct drm_i915_gem_object *obj,
2644 				  struct i915_address_space *vm)
2645 {
2646 	struct i915_vma *vma;
2647 
2648 	vma = i915_gem_obj_to_vma(obj, vm);
2649 	if (!vma)
2650 		vma = __i915_gem_vma_create(obj, vm,
2651 					    i915_is_ggtt(vm) ? &i915_ggtt_view_normal : NULL);
2652 
2653 	return vma;
2654 }
2655 
2656 struct i915_vma *
2657 i915_gem_obj_lookup_or_create_ggtt_vma(struct drm_i915_gem_object *obj,
2658 				       const struct i915_ggtt_view *view)
2659 {
2660 	struct i915_address_space *ggtt = i915_obj_to_ggtt(obj);
2661 	struct i915_vma *vma;
2662 
2663 	if (WARN_ON(!view))
2664 		return ERR_PTR(-EINVAL);
2665 
2666 	vma = i915_gem_obj_to_ggtt_view(obj, view);
2667 
2668 	if (IS_ERR(vma))
2669 		return vma;
2670 
2671 	if (!vma)
2672 		vma = __i915_gem_vma_create(obj, ggtt, view);
2673 
2674 	return vma;
2675 
2676 }
2677 
2678 static void
2679 rotate_pages(dma_addr_t *in, unsigned int width, unsigned int height,
2680 	     struct sg_table *st)
2681 {
2682 	unsigned int column, row;
2683 	unsigned int src_idx;
2684 	struct scatterlist *sg = st->sgl;
2685 
2686 	st->nents = 0;
2687 
2688 	for (column = 0; column < width; column++) {
2689 		src_idx = width * (height - 1) + column;
2690 		for (row = 0; row < height; row++) {
2691 			st->nents++;
2692 			/* We don't need the pages, but need to initialize
2693 			 * the entries so the sg list can be happily traversed.
2694 			 * The only thing we need are DMA addresses.
2695 			 */
2696 			sg_set_page(sg, NULL, PAGE_SIZE, 0);
2697 			sg_dma_address(sg) = in[src_idx];
2698 			sg_dma_len(sg) = PAGE_SIZE;
2699 			sg = sg_next(sg);
2700 			src_idx -= width;
2701 		}
2702 	}
2703 }
2704 
2705 static struct sg_table *
2706 intel_rotate_fb_obj_pages(struct i915_ggtt_view *ggtt_view,
2707 			  struct drm_i915_gem_object *obj)
2708 {
2709 	struct drm_device *dev = obj->base.dev;
2710 	struct intel_rotation_info *rot_info = &ggtt_view->rotation_info;
2711 	unsigned long size, pages, rot_pages;
2712 	struct sg_page_iter sg_iter;
2713 	unsigned long i;
2714 	dma_addr_t *page_addr_list;
2715 	struct sg_table *st;
2716 	unsigned int tile_pitch, tile_height;
2717 	unsigned int width_pages, height_pages;
2718 	int ret = -ENOMEM;
2719 
2720 	pages = obj->base.size / PAGE_SIZE;
2721 
2722 	/* Calculate tiling geometry. */
2723 	tile_height = intel_tile_height(dev, rot_info->pixel_format,
2724 					rot_info->fb_modifier);
2725 	tile_pitch = PAGE_SIZE / tile_height;
2726 	width_pages = DIV_ROUND_UP(rot_info->pitch, tile_pitch);
2727 	height_pages = DIV_ROUND_UP(rot_info->height, tile_height);
2728 	rot_pages = width_pages * height_pages;
2729 	size = rot_pages * PAGE_SIZE;
2730 
2731 	/* Allocate a temporary list of source pages for random access. */
2732 	page_addr_list = drm_malloc_ab(pages, sizeof(dma_addr_t));
2733 	if (!page_addr_list)
2734 		return ERR_PTR(ret);
2735 
2736 	/* Allocate target SG list. */
2737 	st = kmalloc(sizeof(*st), GFP_KERNEL);
2738 	if (!st)
2739 		goto err_st_alloc;
2740 
2741 	ret = sg_alloc_table(st, rot_pages, GFP_KERNEL);
2742 	if (ret)
2743 		goto err_sg_alloc;
2744 
2745 	/* Populate source page list from the object. */
2746 	i = 0;
2747 	for_each_sg_page(obj->pages->sgl, &sg_iter, obj->pages->nents, 0) {
2748 		page_addr_list[i] = sg_page_iter_dma_address(&sg_iter);
2749 		i++;
2750 	}
2751 
2752 	/* Rotate the pages. */
2753 	rotate_pages(page_addr_list, width_pages, height_pages, st);
2754 
2755 	DRM_DEBUG_KMS(
2756 		      "Created rotated page mapping for object size %lu (pitch=%u, height=%u, pixel_format=0x%x, %ux%u tiles, %lu pages).\n",
2757 		      size, rot_info->pitch, rot_info->height,
2758 		      rot_info->pixel_format, width_pages, height_pages,
2759 		      rot_pages);
2760 
2761 	drm_free_large(page_addr_list);
2762 
2763 	return st;
2764 
2765 err_sg_alloc:
2766 	kfree(st);
2767 err_st_alloc:
2768 	drm_free_large(page_addr_list);
2769 
2770 	DRM_DEBUG_KMS(
2771 		      "Failed to create rotated mapping for object size %lu! (%d) (pitch=%u, height=%u, pixel_format=0x%x, %ux%u tiles, %lu pages)\n",
2772 		      size, ret, rot_info->pitch, rot_info->height,
2773 		      rot_info->pixel_format, width_pages, height_pages,
2774 		      rot_pages);
2775 	return ERR_PTR(ret);
2776 }
2777 
2778 static struct sg_table *
2779 intel_partial_pages(const struct i915_ggtt_view *view,
2780 		    struct drm_i915_gem_object *obj)
2781 {
2782 	struct sg_table *st;
2783 	struct scatterlist *sg;
2784 	struct sg_page_iter obj_sg_iter;
2785 	int ret = -ENOMEM;
2786 
2787 	st = kmalloc(sizeof(*st), GFP_KERNEL);
2788 	if (!st)
2789 		goto err_st_alloc;
2790 
2791 	ret = sg_alloc_table(st, view->params.partial.size, GFP_KERNEL);
2792 	if (ret)
2793 		goto err_sg_alloc;
2794 
2795 	sg = st->sgl;
2796 	st->nents = 0;
2797 	for_each_sg_page(obj->pages->sgl, &obj_sg_iter, obj->pages->nents,
2798 		view->params.partial.offset)
2799 	{
2800 		if (st->nents >= view->params.partial.size)
2801 			break;
2802 
2803 		sg_set_page(sg, NULL, PAGE_SIZE, 0);
2804 		sg_dma_address(sg) = sg_page_iter_dma_address(&obj_sg_iter);
2805 		sg_dma_len(sg) = PAGE_SIZE;
2806 
2807 		sg = sg_next(sg);
2808 		st->nents++;
2809 	}
2810 
2811 	return st;
2812 
2813 err_sg_alloc:
2814 	kfree(st);
2815 err_st_alloc:
2816 	return ERR_PTR(ret);
2817 }
2818 
2819 static int
2820 i915_get_ggtt_vma_pages(struct i915_vma *vma)
2821 {
2822 	int ret = 0;
2823 
2824 	if (vma->ggtt_view.pages)
2825 		return 0;
2826 
2827 	if (vma->ggtt_view.type == I915_GGTT_VIEW_NORMAL)
2828 		vma->ggtt_view.pages = vma->obj->pages;
2829 	else if (vma->ggtt_view.type == I915_GGTT_VIEW_ROTATED)
2830 		vma->ggtt_view.pages =
2831 			intel_rotate_fb_obj_pages(&vma->ggtt_view, vma->obj);
2832 	else if (vma->ggtt_view.type == I915_GGTT_VIEW_PARTIAL)
2833 		vma->ggtt_view.pages =
2834 			intel_partial_pages(&vma->ggtt_view, vma->obj);
2835 	else
2836 		WARN_ONCE(1, "GGTT view %u not implemented!\n",
2837 			  vma->ggtt_view.type);
2838 
2839 	if (!vma->ggtt_view.pages) {
2840 		DRM_ERROR("Failed to get pages for GGTT view type %u!\n",
2841 			  vma->ggtt_view.type);
2842 		ret = -EINVAL;
2843 	} else if (IS_ERR(vma->ggtt_view.pages)) {
2844 		ret = PTR_ERR(vma->ggtt_view.pages);
2845 		vma->ggtt_view.pages = NULL;
2846 		DRM_ERROR("Failed to get pages for VMA view type %u (%d)!\n",
2847 			  vma->ggtt_view.type, ret);
2848 	}
2849 
2850 	return ret;
2851 }
2852 
2853 /**
2854  * i915_vma_bind - Sets up PTEs for an VMA in it's corresponding address space.
2855  * @vma: VMA to map
2856  * @cache_level: mapping cache level
2857  * @flags: flags like global or local mapping
2858  *
2859  * DMA addresses are taken from the scatter-gather table of this object (or of
2860  * this VMA in case of non-default GGTT views) and PTE entries set up.
2861  * Note that DMA addresses are also the only part of the SG table we care about.
2862  */
2863 int i915_vma_bind(struct i915_vma *vma, enum i915_cache_level cache_level,
2864 		  u32 flags)
2865 {
2866 	int ret;
2867 	u32 bind_flags;
2868 
2869 	if (WARN_ON(flags == 0))
2870 		return -EINVAL;
2871 
2872 	bind_flags = 0;
2873 	if (flags & PIN_GLOBAL)
2874 		bind_flags |= GLOBAL_BIND;
2875 	if (flags & PIN_USER)
2876 		bind_flags |= LOCAL_BIND;
2877 
2878 	if (flags & PIN_UPDATE)
2879 		bind_flags |= vma->bound;
2880 	else
2881 		bind_flags &= ~vma->bound;
2882 
2883 	if (bind_flags == 0)
2884 		return 0;
2885 
2886 	if (vma->bound == 0 && vma->vm->allocate_va_range) {
2887 		trace_i915_va_alloc(vma->vm,
2888 				    vma->node.start,
2889 				    vma->node.size,
2890 				    VM_TO_TRACE_NAME(vma->vm));
2891 
2892 		ret = vma->vm->allocate_va_range(vma->vm,
2893 						 vma->node.start,
2894 						 vma->node.size);
2895 		if (ret)
2896 			return ret;
2897 	}
2898 
2899 	ret = vma->vm->bind_vma(vma, cache_level, bind_flags);
2900 	if (ret)
2901 		return ret;
2902 
2903 	vma->bound |= bind_flags;
2904 
2905 	return 0;
2906 }
2907 
2908 /**
2909  * i915_ggtt_view_size - Get the size of a GGTT view.
2910  * @obj: Object the view is of.
2911  * @view: The view in question.
2912  *
2913  * @return The size of the GGTT view in bytes.
2914  */
2915 size_t
2916 i915_ggtt_view_size(struct drm_i915_gem_object *obj,
2917 		    const struct i915_ggtt_view *view)
2918 {
2919 	if (view->type == I915_GGTT_VIEW_NORMAL ||
2920 	    view->type == I915_GGTT_VIEW_ROTATED) {
2921 		return obj->base.size;
2922 	} else if (view->type == I915_GGTT_VIEW_PARTIAL) {
2923 		return view->params.partial.size << PAGE_SHIFT;
2924 	} else {
2925 		WARN_ONCE(1, "GGTT view %u not implemented!\n", view->type);
2926 		return obj->base.size;
2927 	}
2928 }
2929