xref: /openbmc/linux/drivers/gpu/drm/i915/gt/intel_gtt.c (revision 979ac5ef)
1 // SPDX-License-Identifier: MIT
2 /*
3  * Copyright © 2020 Intel Corporation
4  */
5 
6 #include <linux/slab.h> /* fault-inject.h is not standalone! */
7 
8 #include <linux/fault-inject.h>
9 #include <linux/sched/mm.h>
10 
11 #include <drm/drm_cache.h>
12 
13 #include "gem/i915_gem_internal.h"
14 #include "gem/i915_gem_lmem.h"
15 #include "i915_reg.h"
16 #include "i915_trace.h"
17 #include "i915_utils.h"
18 #include "intel_gt.h"
19 #include "intel_gt_mcr.h"
20 #include "intel_gt_regs.h"
21 #include "intel_gtt.h"
22 
23 
24 static bool intel_ggtt_update_needs_vtd_wa(struct drm_i915_private *i915)
25 {
26 	return IS_BROXTON(i915) && i915_vtd_active(i915);
27 }
28 
29 bool intel_vm_no_concurrent_access_wa(struct drm_i915_private *i915)
30 {
31 	return IS_CHERRYVIEW(i915) || intel_ggtt_update_needs_vtd_wa(i915);
32 }
33 
34 struct drm_i915_gem_object *alloc_pt_lmem(struct i915_address_space *vm, int sz)
35 {
36 	struct drm_i915_gem_object *obj;
37 
38 	/*
39 	 * To avoid severe over-allocation when dealing with min_page_size
40 	 * restrictions, we override that behaviour here by allowing an object
41 	 * size and page layout which can be smaller. In practice this should be
42 	 * totally fine, since GTT paging structures are not typically inserted
43 	 * into the GTT.
44 	 *
45 	 * Note that we also hit this path for the scratch page, and for this
46 	 * case it might need to be 64K, but that should work fine here since we
47 	 * used the passed in size for the page size, which should ensure it
48 	 * also has the same alignment.
49 	 */
50 	obj = __i915_gem_object_create_lmem_with_ps(vm->i915, sz, sz,
51 						    vm->lmem_pt_obj_flags);
52 	/*
53 	 * Ensure all paging structures for this vm share the same dma-resv
54 	 * object underneath, with the idea that one object_lock() will lock
55 	 * them all at once.
56 	 */
57 	if (!IS_ERR(obj)) {
58 		obj->base.resv = i915_vm_resv_get(vm);
59 		obj->shares_resv_from = vm;
60 	}
61 
62 	return obj;
63 }
64 
65 struct drm_i915_gem_object *alloc_pt_dma(struct i915_address_space *vm, int sz)
66 {
67 	struct drm_i915_gem_object *obj;
68 
69 	if (I915_SELFTEST_ONLY(should_fail(&vm->fault_attr, 1)))
70 		i915_gem_shrink_all(vm->i915);
71 
72 	obj = i915_gem_object_create_internal(vm->i915, sz);
73 	/*
74 	 * Ensure all paging structures for this vm share the same dma-resv
75 	 * object underneath, with the idea that one object_lock() will lock
76 	 * them all at once.
77 	 */
78 	if (!IS_ERR(obj)) {
79 		obj->base.resv = i915_vm_resv_get(vm);
80 		obj->shares_resv_from = vm;
81 	}
82 
83 	return obj;
84 }
85 
86 int map_pt_dma(struct i915_address_space *vm, struct drm_i915_gem_object *obj)
87 {
88 	enum i915_map_type type;
89 	void *vaddr;
90 
91 	type = i915_coherent_map_type(vm->i915, obj, true);
92 	vaddr = i915_gem_object_pin_map_unlocked(obj, type);
93 	if (IS_ERR(vaddr))
94 		return PTR_ERR(vaddr);
95 
96 	i915_gem_object_make_unshrinkable(obj);
97 	return 0;
98 }
99 
100 int map_pt_dma_locked(struct i915_address_space *vm, struct drm_i915_gem_object *obj)
101 {
102 	enum i915_map_type type;
103 	void *vaddr;
104 
105 	type = i915_coherent_map_type(vm->i915, obj, true);
106 	vaddr = i915_gem_object_pin_map(obj, type);
107 	if (IS_ERR(vaddr))
108 		return PTR_ERR(vaddr);
109 
110 	i915_gem_object_make_unshrinkable(obj);
111 	return 0;
112 }
113 
114 static void clear_vm_list(struct list_head *list)
115 {
116 	struct i915_vma *vma, *vn;
117 
118 	list_for_each_entry_safe(vma, vn, list, vm_link) {
119 		struct drm_i915_gem_object *obj = vma->obj;
120 
121 		if (!i915_gem_object_get_rcu(obj)) {
122 			/*
123 			 * Object is dying, but has not yet cleared its
124 			 * vma list.
125 			 * Unbind the dying vma to ensure our list
126 			 * is completely drained. We leave the destruction to
127 			 * the object destructor to avoid the vma
128 			 * disappearing under it.
129 			 */
130 			atomic_and(~I915_VMA_PIN_MASK, &vma->flags);
131 			WARN_ON(__i915_vma_unbind(vma));
132 
133 			/* Remove from the unbound list */
134 			list_del_init(&vma->vm_link);
135 
136 			/*
137 			 * Delay the vm and vm mutex freeing until the
138 			 * object is done with destruction.
139 			 */
140 			i915_vm_resv_get(vma->vm);
141 			vma->vm_ddestroy = true;
142 		} else {
143 			i915_vma_destroy_locked(vma);
144 			i915_gem_object_put(obj);
145 		}
146 
147 	}
148 }
149 
150 static void __i915_vm_close(struct i915_address_space *vm)
151 {
152 	mutex_lock(&vm->mutex);
153 
154 	clear_vm_list(&vm->bound_list);
155 	clear_vm_list(&vm->unbound_list);
156 
157 	/* Check for must-fix unanticipated side-effects */
158 	GEM_BUG_ON(!list_empty(&vm->bound_list));
159 	GEM_BUG_ON(!list_empty(&vm->unbound_list));
160 
161 	mutex_unlock(&vm->mutex);
162 }
163 
164 /* lock the vm into the current ww, if we lock one, we lock all */
165 int i915_vm_lock_objects(struct i915_address_space *vm,
166 			 struct i915_gem_ww_ctx *ww)
167 {
168 	if (vm->scratch[0]->base.resv == &vm->_resv) {
169 		return i915_gem_object_lock(vm->scratch[0], ww);
170 	} else {
171 		struct i915_ppgtt *ppgtt = i915_vm_to_ppgtt(vm);
172 
173 		/* We borrowed the scratch page from ggtt, take the top level object */
174 		return i915_gem_object_lock(ppgtt->pd->pt.base, ww);
175 	}
176 }
177 
178 void i915_address_space_fini(struct i915_address_space *vm)
179 {
180 	drm_mm_takedown(&vm->mm);
181 }
182 
183 /**
184  * i915_vm_resv_release - Final struct i915_address_space destructor
185  * @kref: Pointer to the &i915_address_space.resv_ref member.
186  *
187  * This function is called when the last lock sharer no longer shares the
188  * &i915_address_space._resv lock, and also if we raced when
189  * destroying a vma by the vma destruction
190  */
191 void i915_vm_resv_release(struct kref *kref)
192 {
193 	struct i915_address_space *vm =
194 		container_of(kref, typeof(*vm), resv_ref);
195 
196 	dma_resv_fini(&vm->_resv);
197 	mutex_destroy(&vm->mutex);
198 
199 	kfree(vm);
200 }
201 
202 static void __i915_vm_release(struct work_struct *work)
203 {
204 	struct i915_address_space *vm =
205 		container_of(work, struct i915_address_space, release_work);
206 
207 	__i915_vm_close(vm);
208 
209 	/* Synchronize async unbinds. */
210 	i915_vma_resource_bind_dep_sync_all(vm);
211 
212 	vm->cleanup(vm);
213 	i915_address_space_fini(vm);
214 
215 	i915_vm_resv_put(vm);
216 }
217 
218 void i915_vm_release(struct kref *kref)
219 {
220 	struct i915_address_space *vm =
221 		container_of(kref, struct i915_address_space, ref);
222 
223 	GEM_BUG_ON(i915_is_ggtt(vm));
224 	trace_i915_ppgtt_release(vm);
225 
226 	queue_work(vm->i915->wq, &vm->release_work);
227 }
228 
229 void i915_address_space_init(struct i915_address_space *vm, int subclass)
230 {
231 	kref_init(&vm->ref);
232 
233 	/*
234 	 * Special case for GGTT that has already done an early
235 	 * kref_init here.
236 	 */
237 	if (!kref_read(&vm->resv_ref))
238 		kref_init(&vm->resv_ref);
239 
240 	vm->pending_unbind = RB_ROOT_CACHED;
241 	INIT_WORK(&vm->release_work, __i915_vm_release);
242 
243 	/*
244 	 * The vm->mutex must be reclaim safe (for use in the shrinker).
245 	 * Do a dummy acquire now under fs_reclaim so that any allocation
246 	 * attempt holding the lock is immediately reported by lockdep.
247 	 */
248 	mutex_init(&vm->mutex);
249 	lockdep_set_subclass(&vm->mutex, subclass);
250 
251 	if (!intel_vm_no_concurrent_access_wa(vm->i915)) {
252 		i915_gem_shrinker_taints_mutex(vm->i915, &vm->mutex);
253 	} else {
254 		/*
255 		 * CHV + BXT VTD workaround use stop_machine(),
256 		 * which is allowed to allocate memory. This means &vm->mutex
257 		 * is the outer lock, and in theory we can allocate memory inside
258 		 * it through stop_machine().
259 		 *
260 		 * Add the annotation for this, we use trylock in shrinker.
261 		 */
262 		mutex_acquire(&vm->mutex.dep_map, 0, 0, _THIS_IP_);
263 		might_alloc(GFP_KERNEL);
264 		mutex_release(&vm->mutex.dep_map, _THIS_IP_);
265 	}
266 	dma_resv_init(&vm->_resv);
267 
268 	GEM_BUG_ON(!vm->total);
269 	drm_mm_init(&vm->mm, 0, vm->total);
270 
271 	memset64(vm->min_alignment, I915_GTT_MIN_ALIGNMENT,
272 		 ARRAY_SIZE(vm->min_alignment));
273 
274 	if (HAS_64K_PAGES(vm->i915)) {
275 		vm->min_alignment[INTEL_MEMORY_LOCAL] = I915_GTT_PAGE_SIZE_64K;
276 		vm->min_alignment[INTEL_MEMORY_STOLEN_LOCAL] = I915_GTT_PAGE_SIZE_64K;
277 	}
278 
279 	vm->mm.head_node.color = I915_COLOR_UNEVICTABLE;
280 
281 	INIT_LIST_HEAD(&vm->bound_list);
282 	INIT_LIST_HEAD(&vm->unbound_list);
283 }
284 
285 void *__px_vaddr(struct drm_i915_gem_object *p)
286 {
287 	enum i915_map_type type;
288 
289 	GEM_BUG_ON(!i915_gem_object_has_pages(p));
290 	return page_unpack_bits(p->mm.mapping, &type);
291 }
292 
293 dma_addr_t __px_dma(struct drm_i915_gem_object *p)
294 {
295 	GEM_BUG_ON(!i915_gem_object_has_pages(p));
296 	return sg_dma_address(p->mm.pages->sgl);
297 }
298 
299 struct page *__px_page(struct drm_i915_gem_object *p)
300 {
301 	GEM_BUG_ON(!i915_gem_object_has_pages(p));
302 	return sg_page(p->mm.pages->sgl);
303 }
304 
305 void
306 fill_page_dma(struct drm_i915_gem_object *p, const u64 val, unsigned int count)
307 {
308 	void *vaddr = __px_vaddr(p);
309 
310 	memset64(vaddr, val, count);
311 	drm_clflush_virt_range(vaddr, PAGE_SIZE);
312 }
313 
314 static void poison_scratch_page(struct drm_i915_gem_object *scratch)
315 {
316 	void *vaddr = __px_vaddr(scratch);
317 	u8 val;
318 
319 	val = 0;
320 	if (IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM))
321 		val = POISON_FREE;
322 
323 	memset(vaddr, val, scratch->base.size);
324 	drm_clflush_virt_range(vaddr, scratch->base.size);
325 }
326 
327 int setup_scratch_page(struct i915_address_space *vm)
328 {
329 	unsigned long size;
330 
331 	/*
332 	 * In order to utilize 64K pages for an object with a size < 2M, we will
333 	 * need to support a 64K scratch page, given that every 16th entry for a
334 	 * page-table operating in 64K mode must point to a properly aligned 64K
335 	 * region, including any PTEs which happen to point to scratch.
336 	 *
337 	 * This is only relevant for the 48b PPGTT where we support
338 	 * huge-gtt-pages, see also i915_vma_insert(). However, as we share the
339 	 * scratch (read-only) between all vm, we create one 64k scratch page
340 	 * for all.
341 	 */
342 	size = I915_GTT_PAGE_SIZE_4K;
343 	if (i915_vm_is_4lvl(vm) &&
344 	    HAS_PAGE_SIZES(vm->i915, I915_GTT_PAGE_SIZE_64K) &&
345 	    !HAS_64K_PAGES(vm->i915))
346 		size = I915_GTT_PAGE_SIZE_64K;
347 
348 	do {
349 		struct drm_i915_gem_object *obj;
350 
351 		obj = vm->alloc_scratch_dma(vm, size);
352 		if (IS_ERR(obj))
353 			goto skip;
354 
355 		if (map_pt_dma(vm, obj))
356 			goto skip_obj;
357 
358 		/* We need a single contiguous page for our scratch */
359 		if (obj->mm.page_sizes.sg < size)
360 			goto skip_obj;
361 
362 		/* And it needs to be correspondingly aligned */
363 		if (__px_dma(obj) & (size - 1))
364 			goto skip_obj;
365 
366 		/*
367 		 * Use a non-zero scratch page for debugging.
368 		 *
369 		 * We want a value that should be reasonably obvious
370 		 * to spot in the error state, while also causing a GPU hang
371 		 * if executed. We prefer using a clear page in production, so
372 		 * should it ever be accidentally used, the effect should be
373 		 * fairly benign.
374 		 */
375 		poison_scratch_page(obj);
376 
377 		vm->scratch[0] = obj;
378 		vm->scratch_order = get_order(size);
379 		return 0;
380 
381 skip_obj:
382 		i915_gem_object_put(obj);
383 skip:
384 		if (size == I915_GTT_PAGE_SIZE_4K)
385 			return -ENOMEM;
386 
387 		size = I915_GTT_PAGE_SIZE_4K;
388 	} while (1);
389 }
390 
391 void free_scratch(struct i915_address_space *vm)
392 {
393 	int i;
394 
395 	if (!vm->scratch[0])
396 		return;
397 
398 	for (i = 0; i <= vm->top; i++)
399 		i915_gem_object_put(vm->scratch[i]);
400 }
401 
402 void gtt_write_workarounds(struct intel_gt *gt)
403 {
404 	struct drm_i915_private *i915 = gt->i915;
405 	struct intel_uncore *uncore = gt->uncore;
406 
407 	/*
408 	 * This function is for gtt related workarounds. This function is
409 	 * called on driver load and after a GPU reset, so you can place
410 	 * workarounds here even if they get overwritten by GPU reset.
411 	 */
412 	/* WaIncreaseDefaultTLBEntries:chv,bdw,skl,bxt,kbl,glk,cfl,cnl,icl */
413 	if (IS_BROADWELL(i915))
414 		intel_uncore_write(uncore,
415 				   GEN8_L3_LRA_1_GPGPU,
416 				   GEN8_L3_LRA_1_GPGPU_DEFAULT_VALUE_BDW);
417 	else if (IS_CHERRYVIEW(i915))
418 		intel_uncore_write(uncore,
419 				   GEN8_L3_LRA_1_GPGPU,
420 				   GEN8_L3_LRA_1_GPGPU_DEFAULT_VALUE_CHV);
421 	else if (IS_GEN9_LP(i915))
422 		intel_uncore_write(uncore,
423 				   GEN8_L3_LRA_1_GPGPU,
424 				   GEN9_L3_LRA_1_GPGPU_DEFAULT_VALUE_BXT);
425 	else if (GRAPHICS_VER(i915) >= 9 && GRAPHICS_VER(i915) <= 11)
426 		intel_uncore_write(uncore,
427 				   GEN8_L3_LRA_1_GPGPU,
428 				   GEN9_L3_LRA_1_GPGPU_DEFAULT_VALUE_SKL);
429 
430 	/*
431 	 * To support 64K PTEs we need to first enable the use of the
432 	 * Intermediate-Page-Size(IPS) bit of the PDE field via some magical
433 	 * mmio, otherwise the page-walker will simply ignore the IPS bit. This
434 	 * shouldn't be needed after GEN10.
435 	 *
436 	 * 64K pages were first introduced from BDW+, although technically they
437 	 * only *work* from gen9+. For pre-BDW we instead have the option for
438 	 * 32K pages, but we don't currently have any support for it in our
439 	 * driver.
440 	 */
441 	if (HAS_PAGE_SIZES(i915, I915_GTT_PAGE_SIZE_64K) &&
442 	    GRAPHICS_VER(i915) <= 10)
443 		intel_uncore_rmw(uncore,
444 				 GEN8_GAMW_ECO_DEV_RW_IA,
445 				 0,
446 				 GAMW_ECO_ENABLE_64K_IPS_FIELD);
447 
448 	if (IS_GRAPHICS_VER(i915, 8, 11)) {
449 		bool can_use_gtt_cache = true;
450 
451 		/*
452 		 * According to the BSpec if we use 2M/1G pages then we also
453 		 * need to disable the GTT cache. At least on BDW we can see
454 		 * visual corruption when using 2M pages, and not disabling the
455 		 * GTT cache.
456 		 */
457 		if (HAS_PAGE_SIZES(i915, I915_GTT_PAGE_SIZE_2M))
458 			can_use_gtt_cache = false;
459 
460 		/* WaGttCachingOffByDefault */
461 		intel_uncore_write(uncore,
462 				   HSW_GTT_CACHE_EN,
463 				   can_use_gtt_cache ? GTT_CACHE_EN_ALL : 0);
464 		drm_WARN_ON_ONCE(&i915->drm, can_use_gtt_cache &&
465 				 intel_uncore_read(uncore,
466 						   HSW_GTT_CACHE_EN) == 0);
467 	}
468 }
469 
470 static void tgl_setup_private_ppat(struct intel_uncore *uncore)
471 {
472 	/* TGL doesn't support LLC or AGE settings */
473 	intel_uncore_write(uncore, GEN12_PAT_INDEX(0), GEN8_PPAT_WB);
474 	intel_uncore_write(uncore, GEN12_PAT_INDEX(1), GEN8_PPAT_WC);
475 	intel_uncore_write(uncore, GEN12_PAT_INDEX(2), GEN8_PPAT_WT);
476 	intel_uncore_write(uncore, GEN12_PAT_INDEX(3), GEN8_PPAT_UC);
477 	intel_uncore_write(uncore, GEN12_PAT_INDEX(4), GEN8_PPAT_WB);
478 	intel_uncore_write(uncore, GEN12_PAT_INDEX(5), GEN8_PPAT_WB);
479 	intel_uncore_write(uncore, GEN12_PAT_INDEX(6), GEN8_PPAT_WB);
480 	intel_uncore_write(uncore, GEN12_PAT_INDEX(7), GEN8_PPAT_WB);
481 }
482 
483 static void xehp_setup_private_ppat(struct intel_gt *gt)
484 {
485 	intel_gt_mcr_multicast_write(gt, XEHP_PAT_INDEX(0), GEN8_PPAT_WB);
486 	intel_gt_mcr_multicast_write(gt, XEHP_PAT_INDEX(1), GEN8_PPAT_WC);
487 	intel_gt_mcr_multicast_write(gt, XEHP_PAT_INDEX(2), GEN8_PPAT_WT);
488 	intel_gt_mcr_multicast_write(gt, XEHP_PAT_INDEX(3), GEN8_PPAT_UC);
489 	intel_gt_mcr_multicast_write(gt, XEHP_PAT_INDEX(4), GEN8_PPAT_WB);
490 	intel_gt_mcr_multicast_write(gt, XEHP_PAT_INDEX(5), GEN8_PPAT_WB);
491 	intel_gt_mcr_multicast_write(gt, XEHP_PAT_INDEX(6), GEN8_PPAT_WB);
492 	intel_gt_mcr_multicast_write(gt, XEHP_PAT_INDEX(7), GEN8_PPAT_WB);
493 }
494 
495 static void icl_setup_private_ppat(struct intel_uncore *uncore)
496 {
497 	intel_uncore_write(uncore,
498 			   GEN10_PAT_INDEX(0),
499 			   GEN8_PPAT_WB | GEN8_PPAT_LLC);
500 	intel_uncore_write(uncore,
501 			   GEN10_PAT_INDEX(1),
502 			   GEN8_PPAT_WC | GEN8_PPAT_LLCELLC);
503 	intel_uncore_write(uncore,
504 			   GEN10_PAT_INDEX(2),
505 			   GEN8_PPAT_WB | GEN8_PPAT_ELLC_OVERRIDE);
506 	intel_uncore_write(uncore,
507 			   GEN10_PAT_INDEX(3),
508 			   GEN8_PPAT_UC);
509 	intel_uncore_write(uncore,
510 			   GEN10_PAT_INDEX(4),
511 			   GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(0));
512 	intel_uncore_write(uncore,
513 			   GEN10_PAT_INDEX(5),
514 			   GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(1));
515 	intel_uncore_write(uncore,
516 			   GEN10_PAT_INDEX(6),
517 			   GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(2));
518 	intel_uncore_write(uncore,
519 			   GEN10_PAT_INDEX(7),
520 			   GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(3));
521 }
522 
523 /*
524  * The GGTT and PPGTT need a private PPAT setup in order to handle cacheability
525  * bits. When using advanced contexts each context stores its own PAT, but
526  * writing this data shouldn't be harmful even in those cases.
527  */
528 static void bdw_setup_private_ppat(struct intel_uncore *uncore)
529 {
530 	struct drm_i915_private *i915 = uncore->i915;
531 	u64 pat;
532 
533 	pat = GEN8_PPAT(0, GEN8_PPAT_WB | GEN8_PPAT_LLC) |	/* for normal objects, no eLLC */
534 	      GEN8_PPAT(1, GEN8_PPAT_WC | GEN8_PPAT_LLCELLC) |	/* for something pointing to ptes? */
535 	      GEN8_PPAT(3, GEN8_PPAT_UC) |			/* Uncached objects, mostly for scanout */
536 	      GEN8_PPAT(4, GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(0)) |
537 	      GEN8_PPAT(5, GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(1)) |
538 	      GEN8_PPAT(6, GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(2)) |
539 	      GEN8_PPAT(7, GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(3));
540 
541 	/* for scanout with eLLC */
542 	if (GRAPHICS_VER(i915) >= 9)
543 		pat |= GEN8_PPAT(2, GEN8_PPAT_WB | GEN8_PPAT_ELLC_OVERRIDE);
544 	else
545 		pat |= GEN8_PPAT(2, GEN8_PPAT_WT | GEN8_PPAT_LLCELLC);
546 
547 	intel_uncore_write(uncore, GEN8_PRIVATE_PAT_LO, lower_32_bits(pat));
548 	intel_uncore_write(uncore, GEN8_PRIVATE_PAT_HI, upper_32_bits(pat));
549 }
550 
551 static void chv_setup_private_ppat(struct intel_uncore *uncore)
552 {
553 	u64 pat;
554 
555 	/*
556 	 * Map WB on BDW to snooped on CHV.
557 	 *
558 	 * Only the snoop bit has meaning for CHV, the rest is
559 	 * ignored.
560 	 *
561 	 * The hardware will never snoop for certain types of accesses:
562 	 * - CPU GTT (GMADR->GGTT->no snoop->memory)
563 	 * - PPGTT page tables
564 	 * - some other special cycles
565 	 *
566 	 * As with BDW, we also need to consider the following for GT accesses:
567 	 * "For GGTT, there is NO pat_sel[2:0] from the entry,
568 	 * so RTL will always use the value corresponding to
569 	 * pat_sel = 000".
570 	 * Which means we must set the snoop bit in PAT entry 0
571 	 * in order to keep the global status page working.
572 	 */
573 
574 	pat = GEN8_PPAT(0, CHV_PPAT_SNOOP) |
575 	      GEN8_PPAT(1, 0) |
576 	      GEN8_PPAT(2, 0) |
577 	      GEN8_PPAT(3, 0) |
578 	      GEN8_PPAT(4, CHV_PPAT_SNOOP) |
579 	      GEN8_PPAT(5, CHV_PPAT_SNOOP) |
580 	      GEN8_PPAT(6, CHV_PPAT_SNOOP) |
581 	      GEN8_PPAT(7, CHV_PPAT_SNOOP);
582 
583 	intel_uncore_write(uncore, GEN8_PRIVATE_PAT_LO, lower_32_bits(pat));
584 	intel_uncore_write(uncore, GEN8_PRIVATE_PAT_HI, upper_32_bits(pat));
585 }
586 
587 void setup_private_pat(struct intel_gt *gt)
588 {
589 	struct intel_uncore *uncore = gt->uncore;
590 	struct drm_i915_private *i915 = gt->i915;
591 
592 	GEM_BUG_ON(GRAPHICS_VER(i915) < 8);
593 
594 	if (GRAPHICS_VER_FULL(i915) >= IP_VER(12, 50))
595 		xehp_setup_private_ppat(gt);
596 	else if (GRAPHICS_VER(i915) >= 12)
597 		tgl_setup_private_ppat(uncore);
598 	else if (GRAPHICS_VER(i915) >= 11)
599 		icl_setup_private_ppat(uncore);
600 	else if (IS_CHERRYVIEW(i915) || IS_GEN9_LP(i915))
601 		chv_setup_private_ppat(uncore);
602 	else
603 		bdw_setup_private_ppat(uncore);
604 }
605 
606 struct i915_vma *
607 __vm_create_scratch_for_read(struct i915_address_space *vm, unsigned long size)
608 {
609 	struct drm_i915_gem_object *obj;
610 	struct i915_vma *vma;
611 
612 	obj = i915_gem_object_create_internal(vm->i915, PAGE_ALIGN(size));
613 	if (IS_ERR(obj))
614 		return ERR_CAST(obj);
615 
616 	i915_gem_object_set_cache_coherency(obj, I915_CACHING_CACHED);
617 
618 	vma = i915_vma_instance(obj, vm, NULL);
619 	if (IS_ERR(vma)) {
620 		i915_gem_object_put(obj);
621 		return vma;
622 	}
623 
624 	return vma;
625 }
626 
627 struct i915_vma *
628 __vm_create_scratch_for_read_pinned(struct i915_address_space *vm, unsigned long size)
629 {
630 	struct i915_vma *vma;
631 	int err;
632 
633 	vma = __vm_create_scratch_for_read(vm, size);
634 	if (IS_ERR(vma))
635 		return vma;
636 
637 	err = i915_vma_pin(vma, 0, 0,
638 			   i915_vma_is_ggtt(vma) ? PIN_GLOBAL : PIN_USER);
639 	if (err) {
640 		i915_vma_put(vma);
641 		return ERR_PTR(err);
642 	}
643 
644 	return vma;
645 }
646 
647 #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
648 #include "selftests/mock_gtt.c"
649 #endif
650