xref: /openbmc/linux/drivers/gpu/drm/i915/gt/intel_gtt.c (revision 0242737d)
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_print.h"
21 #include "intel_gt_regs.h"
22 #include "intel_gtt.h"
23 
24 
25 static bool intel_ggtt_update_needs_vtd_wa(struct drm_i915_private *i915)
26 {
27 	return IS_BROXTON(i915) && i915_vtd_active(i915);
28 }
29 
30 bool intel_vm_no_concurrent_access_wa(struct drm_i915_private *i915)
31 {
32 	return IS_CHERRYVIEW(i915) || intel_ggtt_update_needs_vtd_wa(i915);
33 }
34 
35 struct drm_i915_gem_object *alloc_pt_lmem(struct i915_address_space *vm, int sz)
36 {
37 	struct drm_i915_gem_object *obj;
38 
39 	/*
40 	 * To avoid severe over-allocation when dealing with min_page_size
41 	 * restrictions, we override that behaviour here by allowing an object
42 	 * size and page layout which can be smaller. In practice this should be
43 	 * totally fine, since GTT paging structures are not typically inserted
44 	 * into the GTT.
45 	 *
46 	 * Note that we also hit this path for the scratch page, and for this
47 	 * case it might need to be 64K, but that should work fine here since we
48 	 * used the passed in size for the page size, which should ensure it
49 	 * also has the same alignment.
50 	 */
51 	obj = __i915_gem_object_create_lmem_with_ps(vm->i915, sz, sz,
52 						    vm->lmem_pt_obj_flags);
53 	/*
54 	 * Ensure all paging structures for this vm share the same dma-resv
55 	 * object underneath, with the idea that one object_lock() will lock
56 	 * them all at once.
57 	 */
58 	if (!IS_ERR(obj)) {
59 		obj->base.resv = i915_vm_resv_get(vm);
60 		obj->shares_resv_from = vm;
61 	}
62 
63 	return obj;
64 }
65 
66 struct drm_i915_gem_object *alloc_pt_dma(struct i915_address_space *vm, int sz)
67 {
68 	struct drm_i915_gem_object *obj;
69 
70 	if (I915_SELFTEST_ONLY(should_fail(&vm->fault_attr, 1)))
71 		i915_gem_shrink_all(vm->i915);
72 
73 	obj = i915_gem_object_create_internal(vm->i915, sz);
74 	/*
75 	 * Ensure all paging structures for this vm share the same dma-resv
76 	 * object underneath, with the idea that one object_lock() will lock
77 	 * them all at once.
78 	 */
79 	if (!IS_ERR(obj)) {
80 		obj->base.resv = i915_vm_resv_get(vm);
81 		obj->shares_resv_from = vm;
82 	}
83 
84 	return obj;
85 }
86 
87 int map_pt_dma(struct i915_address_space *vm, struct drm_i915_gem_object *obj)
88 {
89 	enum i915_map_type type;
90 	void *vaddr;
91 
92 	type = i915_coherent_map_type(vm->i915, obj, true);
93 	vaddr = i915_gem_object_pin_map_unlocked(obj, type);
94 	if (IS_ERR(vaddr))
95 		return PTR_ERR(vaddr);
96 
97 	i915_gem_object_make_unshrinkable(obj);
98 	return 0;
99 }
100 
101 int map_pt_dma_locked(struct i915_address_space *vm, struct drm_i915_gem_object *obj)
102 {
103 	enum i915_map_type type;
104 	void *vaddr;
105 
106 	type = i915_coherent_map_type(vm->i915, obj, true);
107 	vaddr = i915_gem_object_pin_map(obj, type);
108 	if (IS_ERR(vaddr))
109 		return PTR_ERR(vaddr);
110 
111 	i915_gem_object_make_unshrinkable(obj);
112 	return 0;
113 }
114 
115 static void clear_vm_list(struct list_head *list)
116 {
117 	struct i915_vma *vma, *vn;
118 
119 	list_for_each_entry_safe(vma, vn, list, vm_link) {
120 		struct drm_i915_gem_object *obj = vma->obj;
121 
122 		if (!i915_gem_object_get_rcu(obj)) {
123 			/*
124 			 * Object is dying, but has not yet cleared its
125 			 * vma list.
126 			 * Unbind the dying vma to ensure our list
127 			 * is completely drained. We leave the destruction to
128 			 * the object destructor to avoid the vma
129 			 * disappearing under it.
130 			 */
131 			atomic_and(~I915_VMA_PIN_MASK, &vma->flags);
132 			WARN_ON(__i915_vma_unbind(vma));
133 
134 			/* Remove from the unbound list */
135 			list_del_init(&vma->vm_link);
136 
137 			/*
138 			 * Delay the vm and vm mutex freeing until the
139 			 * object is done with destruction.
140 			 */
141 			i915_vm_resv_get(vma->vm);
142 			vma->vm_ddestroy = true;
143 		} else {
144 			i915_vma_destroy_locked(vma);
145 			i915_gem_object_put(obj);
146 		}
147 
148 	}
149 }
150 
151 static void __i915_vm_close(struct i915_address_space *vm)
152 {
153 	mutex_lock(&vm->mutex);
154 
155 	clear_vm_list(&vm->bound_list);
156 	clear_vm_list(&vm->unbound_list);
157 
158 	/* Check for must-fix unanticipated side-effects */
159 	GEM_BUG_ON(!list_empty(&vm->bound_list));
160 	GEM_BUG_ON(!list_empty(&vm->unbound_list));
161 
162 	mutex_unlock(&vm->mutex);
163 }
164 
165 /* lock the vm into the current ww, if we lock one, we lock all */
166 int i915_vm_lock_objects(struct i915_address_space *vm,
167 			 struct i915_gem_ww_ctx *ww)
168 {
169 	if (vm->scratch[0]->base.resv == &vm->_resv) {
170 		return i915_gem_object_lock(vm->scratch[0], ww);
171 	} else {
172 		struct i915_ppgtt *ppgtt = i915_vm_to_ppgtt(vm);
173 
174 		/* We borrowed the scratch page from ggtt, take the top level object */
175 		return i915_gem_object_lock(ppgtt->pd->pt.base, ww);
176 	}
177 }
178 
179 void i915_address_space_fini(struct i915_address_space *vm)
180 {
181 	drm_mm_takedown(&vm->mm);
182 }
183 
184 /**
185  * i915_vm_resv_release - Final struct i915_address_space destructor
186  * @kref: Pointer to the &i915_address_space.resv_ref member.
187  *
188  * This function is called when the last lock sharer no longer shares the
189  * &i915_address_space._resv lock, and also if we raced when
190  * destroying a vma by the vma destruction
191  */
192 void i915_vm_resv_release(struct kref *kref)
193 {
194 	struct i915_address_space *vm =
195 		container_of(kref, typeof(*vm), resv_ref);
196 
197 	dma_resv_fini(&vm->_resv);
198 	mutex_destroy(&vm->mutex);
199 
200 	kfree(vm);
201 }
202 
203 static void __i915_vm_release(struct work_struct *work)
204 {
205 	struct i915_address_space *vm =
206 		container_of(work, struct i915_address_space, release_work);
207 
208 	__i915_vm_close(vm);
209 
210 	/* Synchronize async unbinds. */
211 	i915_vma_resource_bind_dep_sync_all(vm);
212 
213 	vm->cleanup(vm);
214 	i915_address_space_fini(vm);
215 
216 	i915_vm_resv_put(vm);
217 }
218 
219 void i915_vm_release(struct kref *kref)
220 {
221 	struct i915_address_space *vm =
222 		container_of(kref, struct i915_address_space, ref);
223 
224 	GEM_BUG_ON(i915_is_ggtt(vm));
225 	trace_i915_ppgtt_release(vm);
226 
227 	queue_work(vm->i915->wq, &vm->release_work);
228 }
229 
230 void i915_address_space_init(struct i915_address_space *vm, int subclass)
231 {
232 	kref_init(&vm->ref);
233 
234 	/*
235 	 * Special case for GGTT that has already done an early
236 	 * kref_init here.
237 	 */
238 	if (!kref_read(&vm->resv_ref))
239 		kref_init(&vm->resv_ref);
240 
241 	vm->pending_unbind = RB_ROOT_CACHED;
242 	INIT_WORK(&vm->release_work, __i915_vm_release);
243 
244 	/*
245 	 * The vm->mutex must be reclaim safe (for use in the shrinker).
246 	 * Do a dummy acquire now under fs_reclaim so that any allocation
247 	 * attempt holding the lock is immediately reported by lockdep.
248 	 */
249 	mutex_init(&vm->mutex);
250 	lockdep_set_subclass(&vm->mutex, subclass);
251 
252 	if (!intel_vm_no_concurrent_access_wa(vm->i915)) {
253 		i915_gem_shrinker_taints_mutex(vm->i915, &vm->mutex);
254 	} else {
255 		/*
256 		 * CHV + BXT VTD workaround use stop_machine(),
257 		 * which is allowed to allocate memory. This means &vm->mutex
258 		 * is the outer lock, and in theory we can allocate memory inside
259 		 * it through stop_machine().
260 		 *
261 		 * Add the annotation for this, we use trylock in shrinker.
262 		 */
263 		mutex_acquire(&vm->mutex.dep_map, 0, 0, _THIS_IP_);
264 		might_alloc(GFP_KERNEL);
265 		mutex_release(&vm->mutex.dep_map, _THIS_IP_);
266 	}
267 	dma_resv_init(&vm->_resv);
268 
269 	GEM_BUG_ON(!vm->total);
270 	drm_mm_init(&vm->mm, 0, vm->total);
271 
272 	memset64(vm->min_alignment, I915_GTT_MIN_ALIGNMENT,
273 		 ARRAY_SIZE(vm->min_alignment));
274 
275 	if (HAS_64K_PAGES(vm->i915)) {
276 		vm->min_alignment[INTEL_MEMORY_LOCAL] = I915_GTT_PAGE_SIZE_64K;
277 		vm->min_alignment[INTEL_MEMORY_STOLEN_LOCAL] = I915_GTT_PAGE_SIZE_64K;
278 	}
279 
280 	vm->mm.head_node.color = I915_COLOR_UNEVICTABLE;
281 
282 	INIT_LIST_HEAD(&vm->bound_list);
283 	INIT_LIST_HEAD(&vm->unbound_list);
284 }
285 
286 void *__px_vaddr(struct drm_i915_gem_object *p)
287 {
288 	enum i915_map_type type;
289 
290 	GEM_BUG_ON(!i915_gem_object_has_pages(p));
291 	return page_unpack_bits(p->mm.mapping, &type);
292 }
293 
294 dma_addr_t __px_dma(struct drm_i915_gem_object *p)
295 {
296 	GEM_BUG_ON(!i915_gem_object_has_pages(p));
297 	return sg_dma_address(p->mm.pages->sgl);
298 }
299 
300 struct page *__px_page(struct drm_i915_gem_object *p)
301 {
302 	GEM_BUG_ON(!i915_gem_object_has_pages(p));
303 	return sg_page(p->mm.pages->sgl);
304 }
305 
306 void
307 fill_page_dma(struct drm_i915_gem_object *p, const u64 val, unsigned int count)
308 {
309 	void *vaddr = __px_vaddr(p);
310 
311 	memset64(vaddr, val, count);
312 	drm_clflush_virt_range(vaddr, PAGE_SIZE);
313 }
314 
315 static void poison_scratch_page(struct drm_i915_gem_object *scratch)
316 {
317 	void *vaddr = __px_vaddr(scratch);
318 	u8 val;
319 
320 	val = 0;
321 	if (IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM))
322 		val = POISON_FREE;
323 
324 	memset(vaddr, val, scratch->base.size);
325 	drm_clflush_virt_range(vaddr, scratch->base.size);
326 }
327 
328 int setup_scratch_page(struct i915_address_space *vm)
329 {
330 	unsigned long size;
331 
332 	/*
333 	 * In order to utilize 64K pages for an object with a size < 2M, we will
334 	 * need to support a 64K scratch page, given that every 16th entry for a
335 	 * page-table operating in 64K mode must point to a properly aligned 64K
336 	 * region, including any PTEs which happen to point to scratch.
337 	 *
338 	 * This is only relevant for the 48b PPGTT where we support
339 	 * huge-gtt-pages, see also i915_vma_insert(). However, as we share the
340 	 * scratch (read-only) between all vm, we create one 64k scratch page
341 	 * for all.
342 	 */
343 	size = I915_GTT_PAGE_SIZE_4K;
344 	if (i915_vm_is_4lvl(vm) &&
345 	    HAS_PAGE_SIZES(vm->i915, I915_GTT_PAGE_SIZE_64K) &&
346 	    !HAS_64K_PAGES(vm->i915))
347 		size = I915_GTT_PAGE_SIZE_64K;
348 
349 	do {
350 		struct drm_i915_gem_object *obj;
351 
352 		obj = vm->alloc_scratch_dma(vm, size);
353 		if (IS_ERR(obj))
354 			goto skip;
355 
356 		if (map_pt_dma(vm, obj))
357 			goto skip_obj;
358 
359 		/* We need a single contiguous page for our scratch */
360 		if (obj->mm.page_sizes.sg < size)
361 			goto skip_obj;
362 
363 		/* And it needs to be correspondingly aligned */
364 		if (__px_dma(obj) & (size - 1))
365 			goto skip_obj;
366 
367 		/*
368 		 * Use a non-zero scratch page for debugging.
369 		 *
370 		 * We want a value that should be reasonably obvious
371 		 * to spot in the error state, while also causing a GPU hang
372 		 * if executed. We prefer using a clear page in production, so
373 		 * should it ever be accidentally used, the effect should be
374 		 * fairly benign.
375 		 */
376 		poison_scratch_page(obj);
377 
378 		vm->scratch[0] = obj;
379 		vm->scratch_order = get_order(size);
380 		return 0;
381 
382 skip_obj:
383 		i915_gem_object_put(obj);
384 skip:
385 		if (size == I915_GTT_PAGE_SIZE_4K)
386 			return -ENOMEM;
387 
388 		size = I915_GTT_PAGE_SIZE_4K;
389 	} while (1);
390 }
391 
392 void free_scratch(struct i915_address_space *vm)
393 {
394 	int i;
395 
396 	if (!vm->scratch[0])
397 		return;
398 
399 	for (i = 0; i <= vm->top; i++)
400 		i915_gem_object_put(vm->scratch[i]);
401 }
402 
403 void gtt_write_workarounds(struct intel_gt *gt)
404 {
405 	struct drm_i915_private *i915 = gt->i915;
406 	struct intel_uncore *uncore = gt->uncore;
407 
408 	/*
409 	 * This function is for gtt related workarounds. This function is
410 	 * called on driver load and after a GPU reset, so you can place
411 	 * workarounds here even if they get overwritten by GPU reset.
412 	 */
413 	/* WaIncreaseDefaultTLBEntries:chv,bdw,skl,bxt,kbl,glk,cfl,cnl,icl */
414 	if (IS_BROADWELL(i915))
415 		intel_uncore_write(uncore,
416 				   GEN8_L3_LRA_1_GPGPU,
417 				   GEN8_L3_LRA_1_GPGPU_DEFAULT_VALUE_BDW);
418 	else if (IS_CHERRYVIEW(i915))
419 		intel_uncore_write(uncore,
420 				   GEN8_L3_LRA_1_GPGPU,
421 				   GEN8_L3_LRA_1_GPGPU_DEFAULT_VALUE_CHV);
422 	else if (IS_GEN9_LP(i915))
423 		intel_uncore_write(uncore,
424 				   GEN8_L3_LRA_1_GPGPU,
425 				   GEN9_L3_LRA_1_GPGPU_DEFAULT_VALUE_BXT);
426 	else if (GRAPHICS_VER(i915) >= 9 && GRAPHICS_VER(i915) <= 11)
427 		intel_uncore_write(uncore,
428 				   GEN8_L3_LRA_1_GPGPU,
429 				   GEN9_L3_LRA_1_GPGPU_DEFAULT_VALUE_SKL);
430 
431 	/*
432 	 * To support 64K PTEs we need to first enable the use of the
433 	 * Intermediate-Page-Size(IPS) bit of the PDE field via some magical
434 	 * mmio, otherwise the page-walker will simply ignore the IPS bit. This
435 	 * shouldn't be needed after GEN10.
436 	 *
437 	 * 64K pages were first introduced from BDW+, although technically they
438 	 * only *work* from gen9+. For pre-BDW we instead have the option for
439 	 * 32K pages, but we don't currently have any support for it in our
440 	 * driver.
441 	 */
442 	if (HAS_PAGE_SIZES(i915, I915_GTT_PAGE_SIZE_64K) &&
443 	    GRAPHICS_VER(i915) <= 10)
444 		intel_uncore_rmw(uncore,
445 				 GEN8_GAMW_ECO_DEV_RW_IA,
446 				 0,
447 				 GAMW_ECO_ENABLE_64K_IPS_FIELD);
448 
449 	if (IS_GRAPHICS_VER(i915, 8, 11)) {
450 		bool can_use_gtt_cache = true;
451 
452 		/*
453 		 * According to the BSpec if we use 2M/1G pages then we also
454 		 * need to disable the GTT cache. At least on BDW we can see
455 		 * visual corruption when using 2M pages, and not disabling the
456 		 * GTT cache.
457 		 */
458 		if (HAS_PAGE_SIZES(i915, I915_GTT_PAGE_SIZE_2M))
459 			can_use_gtt_cache = false;
460 
461 		/* WaGttCachingOffByDefault */
462 		intel_uncore_write(uncore,
463 				   HSW_GTT_CACHE_EN,
464 				   can_use_gtt_cache ? GTT_CACHE_EN_ALL : 0);
465 		gt_WARN_ON_ONCE(gt, can_use_gtt_cache &&
466 				intel_uncore_read(uncore,
467 						  HSW_GTT_CACHE_EN) == 0);
468 	}
469 }
470 
471 static void xelpmp_setup_private_ppat(struct intel_uncore *uncore)
472 {
473 	intel_uncore_write(uncore, XELPMP_PAT_INDEX(0),
474 			   MTL_PPAT_L4_0_WB);
475 	intel_uncore_write(uncore, XELPMP_PAT_INDEX(1),
476 			   MTL_PPAT_L4_1_WT);
477 	intel_uncore_write(uncore, XELPMP_PAT_INDEX(2),
478 			   MTL_PPAT_L4_3_UC);
479 	intel_uncore_write(uncore, XELPMP_PAT_INDEX(3),
480 			   MTL_PPAT_L4_0_WB | MTL_2_COH_1W);
481 	intel_uncore_write(uncore, XELPMP_PAT_INDEX(4),
482 			   MTL_PPAT_L4_0_WB | MTL_3_COH_2W);
483 
484 	/*
485 	 * Remaining PAT entries are left at the hardware-default
486 	 * fully-cached setting
487 	 */
488 }
489 
490 static void xelpg_setup_private_ppat(struct intel_gt *gt)
491 {
492 	intel_gt_mcr_multicast_write(gt, XEHP_PAT_INDEX(0),
493 				     MTL_PPAT_L4_0_WB);
494 	intel_gt_mcr_multicast_write(gt, XEHP_PAT_INDEX(1),
495 				     MTL_PPAT_L4_1_WT);
496 	intel_gt_mcr_multicast_write(gt, XEHP_PAT_INDEX(2),
497 				     MTL_PPAT_L4_3_UC);
498 	intel_gt_mcr_multicast_write(gt, XEHP_PAT_INDEX(3),
499 				     MTL_PPAT_L4_0_WB | MTL_2_COH_1W);
500 	intel_gt_mcr_multicast_write(gt, XEHP_PAT_INDEX(4),
501 				     MTL_PPAT_L4_0_WB | MTL_3_COH_2W);
502 
503 	/*
504 	 * Remaining PAT entries are left at the hardware-default
505 	 * fully-cached setting
506 	 */
507 }
508 
509 static void tgl_setup_private_ppat(struct intel_uncore *uncore)
510 {
511 	/* TGL doesn't support LLC or AGE settings */
512 	intel_uncore_write(uncore, GEN12_PAT_INDEX(0), GEN8_PPAT_WB);
513 	intel_uncore_write(uncore, GEN12_PAT_INDEX(1), GEN8_PPAT_WC);
514 	intel_uncore_write(uncore, GEN12_PAT_INDEX(2), GEN8_PPAT_WT);
515 	intel_uncore_write(uncore, GEN12_PAT_INDEX(3), GEN8_PPAT_UC);
516 	intel_uncore_write(uncore, GEN12_PAT_INDEX(4), GEN8_PPAT_WB);
517 	intel_uncore_write(uncore, GEN12_PAT_INDEX(5), GEN8_PPAT_WB);
518 	intel_uncore_write(uncore, GEN12_PAT_INDEX(6), GEN8_PPAT_WB);
519 	intel_uncore_write(uncore, GEN12_PAT_INDEX(7), GEN8_PPAT_WB);
520 }
521 
522 static void xehp_setup_private_ppat(struct intel_gt *gt)
523 {
524 	enum forcewake_domains fw;
525 	unsigned long flags;
526 
527 	fw = intel_uncore_forcewake_for_reg(gt->uncore, _MMIO(XEHP_PAT_INDEX(0).reg),
528 					    FW_REG_WRITE);
529 	intel_uncore_forcewake_get(gt->uncore, fw);
530 
531 	intel_gt_mcr_lock(gt, &flags);
532 	intel_gt_mcr_multicast_write_fw(gt, XEHP_PAT_INDEX(0), GEN8_PPAT_WB);
533 	intel_gt_mcr_multicast_write_fw(gt, XEHP_PAT_INDEX(1), GEN8_PPAT_WC);
534 	intel_gt_mcr_multicast_write_fw(gt, XEHP_PAT_INDEX(2), GEN8_PPAT_WT);
535 	intel_gt_mcr_multicast_write_fw(gt, XEHP_PAT_INDEX(3), GEN8_PPAT_UC);
536 	intel_gt_mcr_multicast_write_fw(gt, XEHP_PAT_INDEX(4), GEN8_PPAT_WB);
537 	intel_gt_mcr_multicast_write_fw(gt, XEHP_PAT_INDEX(5), GEN8_PPAT_WB);
538 	intel_gt_mcr_multicast_write_fw(gt, XEHP_PAT_INDEX(6), GEN8_PPAT_WB);
539 	intel_gt_mcr_multicast_write_fw(gt, XEHP_PAT_INDEX(7), GEN8_PPAT_WB);
540 	intel_gt_mcr_unlock(gt, flags);
541 
542 	intel_uncore_forcewake_put(gt->uncore, fw);
543 }
544 
545 static void icl_setup_private_ppat(struct intel_uncore *uncore)
546 {
547 	intel_uncore_write(uncore,
548 			   GEN10_PAT_INDEX(0),
549 			   GEN8_PPAT_WB | GEN8_PPAT_LLC);
550 	intel_uncore_write(uncore,
551 			   GEN10_PAT_INDEX(1),
552 			   GEN8_PPAT_WC | GEN8_PPAT_LLCELLC);
553 	intel_uncore_write(uncore,
554 			   GEN10_PAT_INDEX(2),
555 			   GEN8_PPAT_WB | GEN8_PPAT_ELLC_OVERRIDE);
556 	intel_uncore_write(uncore,
557 			   GEN10_PAT_INDEX(3),
558 			   GEN8_PPAT_UC);
559 	intel_uncore_write(uncore,
560 			   GEN10_PAT_INDEX(4),
561 			   GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(0));
562 	intel_uncore_write(uncore,
563 			   GEN10_PAT_INDEX(5),
564 			   GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(1));
565 	intel_uncore_write(uncore,
566 			   GEN10_PAT_INDEX(6),
567 			   GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(2));
568 	intel_uncore_write(uncore,
569 			   GEN10_PAT_INDEX(7),
570 			   GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(3));
571 }
572 
573 /*
574  * The GGTT and PPGTT need a private PPAT setup in order to handle cacheability
575  * bits. When using advanced contexts each context stores its own PAT, but
576  * writing this data shouldn't be harmful even in those cases.
577  */
578 static void bdw_setup_private_ppat(struct intel_uncore *uncore)
579 {
580 	struct drm_i915_private *i915 = uncore->i915;
581 	u64 pat;
582 
583 	pat = GEN8_PPAT(0, GEN8_PPAT_WB | GEN8_PPAT_LLC) |	/* for normal objects, no eLLC */
584 	      GEN8_PPAT(1, GEN8_PPAT_WC | GEN8_PPAT_LLCELLC) |	/* for something pointing to ptes? */
585 	      GEN8_PPAT(3, GEN8_PPAT_UC) |			/* Uncached objects, mostly for scanout */
586 	      GEN8_PPAT(4, GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(0)) |
587 	      GEN8_PPAT(5, GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(1)) |
588 	      GEN8_PPAT(6, GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(2)) |
589 	      GEN8_PPAT(7, GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(3));
590 
591 	/* for scanout with eLLC */
592 	if (GRAPHICS_VER(i915) >= 9)
593 		pat |= GEN8_PPAT(2, GEN8_PPAT_WB | GEN8_PPAT_ELLC_OVERRIDE);
594 	else
595 		pat |= GEN8_PPAT(2, GEN8_PPAT_WT | GEN8_PPAT_LLCELLC);
596 
597 	intel_uncore_write(uncore, GEN8_PRIVATE_PAT_LO, lower_32_bits(pat));
598 	intel_uncore_write(uncore, GEN8_PRIVATE_PAT_HI, upper_32_bits(pat));
599 }
600 
601 static void chv_setup_private_ppat(struct intel_uncore *uncore)
602 {
603 	u64 pat;
604 
605 	/*
606 	 * Map WB on BDW to snooped on CHV.
607 	 *
608 	 * Only the snoop bit has meaning for CHV, the rest is
609 	 * ignored.
610 	 *
611 	 * The hardware will never snoop for certain types of accesses:
612 	 * - CPU GTT (GMADR->GGTT->no snoop->memory)
613 	 * - PPGTT page tables
614 	 * - some other special cycles
615 	 *
616 	 * As with BDW, we also need to consider the following for GT accesses:
617 	 * "For GGTT, there is NO pat_sel[2:0] from the entry,
618 	 * so RTL will always use the value corresponding to
619 	 * pat_sel = 000".
620 	 * Which means we must set the snoop bit in PAT entry 0
621 	 * in order to keep the global status page working.
622 	 */
623 
624 	pat = GEN8_PPAT(0, CHV_PPAT_SNOOP) |
625 	      GEN8_PPAT(1, 0) |
626 	      GEN8_PPAT(2, 0) |
627 	      GEN8_PPAT(3, 0) |
628 	      GEN8_PPAT(4, CHV_PPAT_SNOOP) |
629 	      GEN8_PPAT(5, CHV_PPAT_SNOOP) |
630 	      GEN8_PPAT(6, CHV_PPAT_SNOOP) |
631 	      GEN8_PPAT(7, CHV_PPAT_SNOOP);
632 
633 	intel_uncore_write(uncore, GEN8_PRIVATE_PAT_LO, lower_32_bits(pat));
634 	intel_uncore_write(uncore, GEN8_PRIVATE_PAT_HI, upper_32_bits(pat));
635 }
636 
637 void setup_private_pat(struct intel_gt *gt)
638 {
639 	struct intel_uncore *uncore = gt->uncore;
640 	struct drm_i915_private *i915 = gt->i915;
641 
642 	GEM_BUG_ON(GRAPHICS_VER(i915) < 8);
643 
644 	if (gt->type == GT_MEDIA) {
645 		xelpmp_setup_private_ppat(gt->uncore);
646 		return;
647 	}
648 
649 	if (GRAPHICS_VER_FULL(i915) >= IP_VER(12, 70))
650 		xelpg_setup_private_ppat(gt);
651 	else if (GRAPHICS_VER_FULL(i915) >= IP_VER(12, 50))
652 		xehp_setup_private_ppat(gt);
653 	else if (GRAPHICS_VER(i915) >= 12)
654 		tgl_setup_private_ppat(uncore);
655 	else if (GRAPHICS_VER(i915) >= 11)
656 		icl_setup_private_ppat(uncore);
657 	else if (IS_CHERRYVIEW(i915) || IS_GEN9_LP(i915))
658 		chv_setup_private_ppat(uncore);
659 	else
660 		bdw_setup_private_ppat(uncore);
661 }
662 
663 struct i915_vma *
664 __vm_create_scratch_for_read(struct i915_address_space *vm, unsigned long size)
665 {
666 	struct drm_i915_gem_object *obj;
667 	struct i915_vma *vma;
668 
669 	obj = i915_gem_object_create_internal(vm->i915, PAGE_ALIGN(size));
670 	if (IS_ERR(obj))
671 		return ERR_CAST(obj);
672 
673 	i915_gem_object_set_cache_coherency(obj, I915_CACHE_LLC);
674 
675 	vma = i915_vma_instance(obj, vm, NULL);
676 	if (IS_ERR(vma)) {
677 		i915_gem_object_put(obj);
678 		return vma;
679 	}
680 
681 	return vma;
682 }
683 
684 struct i915_vma *
685 __vm_create_scratch_for_read_pinned(struct i915_address_space *vm, unsigned long size)
686 {
687 	struct i915_vma *vma;
688 	int err;
689 
690 	vma = __vm_create_scratch_for_read(vm, size);
691 	if (IS_ERR(vma))
692 		return vma;
693 
694 	err = i915_vma_pin(vma, 0, 0,
695 			   i915_vma_is_ggtt(vma) ? PIN_GLOBAL : PIN_USER);
696 	if (err) {
697 		i915_vma_put(vma);
698 		return ERR_PTR(err);
699 	}
700 
701 	return vma;
702 }
703 
704 #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
705 #include "selftests/mock_gtt.c"
706 #endif
707