xref: /linux/drivers/gpu/drm/i915/gt/intel_gtt.c (revision b77e0ce62d63a761ffb7f7245a215a49f5921c2f)
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 
10 #include "i915_trace.h"
11 #include "intel_gt.h"
12 #include "intel_gtt.h"
13 
14 struct drm_i915_gem_object *alloc_pt_dma(struct i915_address_space *vm, int sz)
15 {
16 	if (I915_SELFTEST_ONLY(should_fail(&vm->fault_attr, 1)))
17 		i915_gem_shrink_all(vm->i915);
18 
19 	return i915_gem_object_create_internal(vm->i915, sz);
20 }
21 
22 int pin_pt_dma(struct i915_address_space *vm, struct drm_i915_gem_object *obj)
23 {
24 	int err;
25 
26 	err = i915_gem_object_pin_pages(obj);
27 	if (err)
28 		return err;
29 
30 	i915_gem_object_make_unshrinkable(obj);
31 	return 0;
32 }
33 
34 void __i915_vm_close(struct i915_address_space *vm)
35 {
36 	struct i915_vma *vma, *vn;
37 
38 	if (!atomic_dec_and_mutex_lock(&vm->open, &vm->mutex))
39 		return;
40 
41 	list_for_each_entry_safe(vma, vn, &vm->bound_list, vm_link) {
42 		struct drm_i915_gem_object *obj = vma->obj;
43 
44 		/* Keep the obj (and hence the vma) alive as _we_ destroy it */
45 		if (!kref_get_unless_zero(&obj->base.refcount))
46 			continue;
47 
48 		atomic_and(~I915_VMA_PIN_MASK, &vma->flags);
49 		WARN_ON(__i915_vma_unbind(vma));
50 		__i915_vma_put(vma);
51 
52 		i915_gem_object_put(obj);
53 	}
54 	GEM_BUG_ON(!list_empty(&vm->bound_list));
55 
56 	mutex_unlock(&vm->mutex);
57 }
58 
59 void i915_address_space_fini(struct i915_address_space *vm)
60 {
61 	drm_mm_takedown(&vm->mm);
62 	mutex_destroy(&vm->mutex);
63 }
64 
65 static void __i915_vm_release(struct work_struct *work)
66 {
67 	struct i915_address_space *vm =
68 		container_of(work, struct i915_address_space, rcu.work);
69 
70 	vm->cleanup(vm);
71 	i915_address_space_fini(vm);
72 
73 	kfree(vm);
74 }
75 
76 void i915_vm_release(struct kref *kref)
77 {
78 	struct i915_address_space *vm =
79 		container_of(kref, struct i915_address_space, ref);
80 
81 	GEM_BUG_ON(i915_is_ggtt(vm));
82 	trace_i915_ppgtt_release(vm);
83 
84 	queue_rcu_work(vm->i915->wq, &vm->rcu);
85 }
86 
87 void i915_address_space_init(struct i915_address_space *vm, int subclass)
88 {
89 	kref_init(&vm->ref);
90 	INIT_RCU_WORK(&vm->rcu, __i915_vm_release);
91 	atomic_set(&vm->open, 1);
92 
93 	/*
94 	 * The vm->mutex must be reclaim safe (for use in the shrinker).
95 	 * Do a dummy acquire now under fs_reclaim so that any allocation
96 	 * attempt holding the lock is immediately reported by lockdep.
97 	 */
98 	mutex_init(&vm->mutex);
99 	lockdep_set_subclass(&vm->mutex, subclass);
100 	i915_gem_shrinker_taints_mutex(vm->i915, &vm->mutex);
101 
102 	GEM_BUG_ON(!vm->total);
103 	drm_mm_init(&vm->mm, 0, vm->total);
104 	vm->mm.head_node.color = I915_COLOR_UNEVICTABLE;
105 
106 	INIT_LIST_HEAD(&vm->bound_list);
107 }
108 
109 void clear_pages(struct i915_vma *vma)
110 {
111 	GEM_BUG_ON(!vma->pages);
112 
113 	if (vma->pages != vma->obj->mm.pages) {
114 		sg_free_table(vma->pages);
115 		kfree(vma->pages);
116 	}
117 	vma->pages = NULL;
118 
119 	memset(&vma->page_sizes, 0, sizeof(vma->page_sizes));
120 }
121 
122 dma_addr_t __px_dma(struct drm_i915_gem_object *p)
123 {
124 	GEM_BUG_ON(!i915_gem_object_has_pages(p));
125 	return sg_dma_address(p->mm.pages->sgl);
126 }
127 
128 struct page *__px_page(struct drm_i915_gem_object *p)
129 {
130 	GEM_BUG_ON(!i915_gem_object_has_pages(p));
131 	return sg_page(p->mm.pages->sgl);
132 }
133 
134 void
135 fill_page_dma(struct drm_i915_gem_object *p, const u64 val, unsigned int count)
136 {
137 	struct page *page = __px_page(p);
138 	void *vaddr;
139 
140 	vaddr = kmap(page);
141 	memset64(vaddr, val, count);
142 	clflush_cache_range(vaddr, PAGE_SIZE);
143 	kunmap(page);
144 }
145 
146 static void poison_scratch_page(struct drm_i915_gem_object *scratch)
147 {
148 	struct sgt_iter sgt;
149 	struct page *page;
150 	u8 val;
151 
152 	val = 0;
153 	if (IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM))
154 		val = POISON_FREE;
155 
156 	for_each_sgt_page(page, sgt, scratch->mm.pages) {
157 		void *vaddr;
158 
159 		vaddr = kmap(page);
160 		memset(vaddr, val, PAGE_SIZE);
161 		kunmap(page);
162 	}
163 }
164 
165 int setup_scratch_page(struct i915_address_space *vm)
166 {
167 	unsigned long size;
168 
169 	/*
170 	 * In order to utilize 64K pages for an object with a size < 2M, we will
171 	 * need to support a 64K scratch page, given that every 16th entry for a
172 	 * page-table operating in 64K mode must point to a properly aligned 64K
173 	 * region, including any PTEs which happen to point to scratch.
174 	 *
175 	 * This is only relevant for the 48b PPGTT where we support
176 	 * huge-gtt-pages, see also i915_vma_insert(). However, as we share the
177 	 * scratch (read-only) between all vm, we create one 64k scratch page
178 	 * for all.
179 	 */
180 	size = I915_GTT_PAGE_SIZE_4K;
181 	if (i915_vm_is_4lvl(vm) &&
182 	    HAS_PAGE_SIZES(vm->i915, I915_GTT_PAGE_SIZE_64K))
183 		size = I915_GTT_PAGE_SIZE_64K;
184 
185 	do {
186 		struct drm_i915_gem_object *obj;
187 
188 		obj = vm->alloc_pt_dma(vm, size);
189 		if (IS_ERR(obj))
190 			goto skip;
191 
192 		if (pin_pt_dma(vm, obj))
193 			goto skip_obj;
194 
195 		/* We need a single contiguous page for our scratch */
196 		if (obj->mm.page_sizes.sg < size)
197 			goto skip_obj;
198 
199 		/* And it needs to be correspondingly aligned */
200 		if (__px_dma(obj) & (size - 1))
201 			goto skip_obj;
202 
203 		/*
204 		 * Use a non-zero scratch page for debugging.
205 		 *
206 		 * We want a value that should be reasonably obvious
207 		 * to spot in the error state, while also causing a GPU hang
208 		 * if executed. We prefer using a clear page in production, so
209 		 * should it ever be accidentally used, the effect should be
210 		 * fairly benign.
211 		 */
212 		poison_scratch_page(obj);
213 
214 		vm->scratch[0] = obj;
215 		vm->scratch_order = get_order(size);
216 		return 0;
217 
218 skip_obj:
219 		i915_gem_object_put(obj);
220 skip:
221 		if (size == I915_GTT_PAGE_SIZE_4K)
222 			return -ENOMEM;
223 
224 		size = I915_GTT_PAGE_SIZE_4K;
225 	} while (1);
226 }
227 
228 void free_scratch(struct i915_address_space *vm)
229 {
230 	int i;
231 
232 	for (i = 0; i <= vm->top; i++)
233 		i915_gem_object_put(vm->scratch[i]);
234 }
235 
236 void gtt_write_workarounds(struct intel_gt *gt)
237 {
238 	struct drm_i915_private *i915 = gt->i915;
239 	struct intel_uncore *uncore = gt->uncore;
240 
241 	/*
242 	 * This function is for gtt related workarounds. This function is
243 	 * called on driver load and after a GPU reset, so you can place
244 	 * workarounds here even if they get overwritten by GPU reset.
245 	 */
246 	/* WaIncreaseDefaultTLBEntries:chv,bdw,skl,bxt,kbl,glk,cfl,cnl,icl */
247 	if (IS_BROADWELL(i915))
248 		intel_uncore_write(uncore,
249 				   GEN8_L3_LRA_1_GPGPU,
250 				   GEN8_L3_LRA_1_GPGPU_DEFAULT_VALUE_BDW);
251 	else if (IS_CHERRYVIEW(i915))
252 		intel_uncore_write(uncore,
253 				   GEN8_L3_LRA_1_GPGPU,
254 				   GEN8_L3_LRA_1_GPGPU_DEFAULT_VALUE_CHV);
255 	else if (IS_GEN9_LP(i915))
256 		intel_uncore_write(uncore,
257 				   GEN8_L3_LRA_1_GPGPU,
258 				   GEN9_L3_LRA_1_GPGPU_DEFAULT_VALUE_BXT);
259 	else if (INTEL_GEN(i915) >= 9 && INTEL_GEN(i915) <= 11)
260 		intel_uncore_write(uncore,
261 				   GEN8_L3_LRA_1_GPGPU,
262 				   GEN9_L3_LRA_1_GPGPU_DEFAULT_VALUE_SKL);
263 
264 	/*
265 	 * To support 64K PTEs we need to first enable the use of the
266 	 * Intermediate-Page-Size(IPS) bit of the PDE field via some magical
267 	 * mmio, otherwise the page-walker will simply ignore the IPS bit. This
268 	 * shouldn't be needed after GEN10.
269 	 *
270 	 * 64K pages were first introduced from BDW+, although technically they
271 	 * only *work* from gen9+. For pre-BDW we instead have the option for
272 	 * 32K pages, but we don't currently have any support for it in our
273 	 * driver.
274 	 */
275 	if (HAS_PAGE_SIZES(i915, I915_GTT_PAGE_SIZE_64K) &&
276 	    INTEL_GEN(i915) <= 10)
277 		intel_uncore_rmw(uncore,
278 				 GEN8_GAMW_ECO_DEV_RW_IA,
279 				 0,
280 				 GAMW_ECO_ENABLE_64K_IPS_FIELD);
281 
282 	if (IS_GEN_RANGE(i915, 8, 11)) {
283 		bool can_use_gtt_cache = true;
284 
285 		/*
286 		 * According to the BSpec if we use 2M/1G pages then we also
287 		 * need to disable the GTT cache. At least on BDW we can see
288 		 * visual corruption when using 2M pages, and not disabling the
289 		 * GTT cache.
290 		 */
291 		if (HAS_PAGE_SIZES(i915, I915_GTT_PAGE_SIZE_2M))
292 			can_use_gtt_cache = false;
293 
294 		/* WaGttCachingOffByDefault */
295 		intel_uncore_write(uncore,
296 				   HSW_GTT_CACHE_EN,
297 				   can_use_gtt_cache ? GTT_CACHE_EN_ALL : 0);
298 		drm_WARN_ON_ONCE(&i915->drm, can_use_gtt_cache &&
299 				 intel_uncore_read(uncore,
300 						   HSW_GTT_CACHE_EN) == 0);
301 	}
302 }
303 
304 static void tgl_setup_private_ppat(struct intel_uncore *uncore)
305 {
306 	/* TGL doesn't support LLC or AGE settings */
307 	intel_uncore_write(uncore, GEN12_PAT_INDEX(0), GEN8_PPAT_WB);
308 	intel_uncore_write(uncore, GEN12_PAT_INDEX(1), GEN8_PPAT_WC);
309 	intel_uncore_write(uncore, GEN12_PAT_INDEX(2), GEN8_PPAT_WT);
310 	intel_uncore_write(uncore, GEN12_PAT_INDEX(3), GEN8_PPAT_UC);
311 	intel_uncore_write(uncore, GEN12_PAT_INDEX(4), GEN8_PPAT_WB);
312 	intel_uncore_write(uncore, GEN12_PAT_INDEX(5), GEN8_PPAT_WB);
313 	intel_uncore_write(uncore, GEN12_PAT_INDEX(6), GEN8_PPAT_WB);
314 	intel_uncore_write(uncore, GEN12_PAT_INDEX(7), GEN8_PPAT_WB);
315 }
316 
317 static void cnl_setup_private_ppat(struct intel_uncore *uncore)
318 {
319 	intel_uncore_write(uncore,
320 			   GEN10_PAT_INDEX(0),
321 			   GEN8_PPAT_WB | GEN8_PPAT_LLC);
322 	intel_uncore_write(uncore,
323 			   GEN10_PAT_INDEX(1),
324 			   GEN8_PPAT_WC | GEN8_PPAT_LLCELLC);
325 	intel_uncore_write(uncore,
326 			   GEN10_PAT_INDEX(2),
327 			   GEN8_PPAT_WB | GEN8_PPAT_ELLC_OVERRIDE);
328 	intel_uncore_write(uncore,
329 			   GEN10_PAT_INDEX(3),
330 			   GEN8_PPAT_UC);
331 	intel_uncore_write(uncore,
332 			   GEN10_PAT_INDEX(4),
333 			   GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(0));
334 	intel_uncore_write(uncore,
335 			   GEN10_PAT_INDEX(5),
336 			   GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(1));
337 	intel_uncore_write(uncore,
338 			   GEN10_PAT_INDEX(6),
339 			   GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(2));
340 	intel_uncore_write(uncore,
341 			   GEN10_PAT_INDEX(7),
342 			   GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(3));
343 }
344 
345 /*
346  * The GGTT and PPGTT need a private PPAT setup in order to handle cacheability
347  * bits. When using advanced contexts each context stores its own PAT, but
348  * writing this data shouldn't be harmful even in those cases.
349  */
350 static void bdw_setup_private_ppat(struct intel_uncore *uncore)
351 {
352 	struct drm_i915_private *i915 = uncore->i915;
353 	u64 pat;
354 
355 	pat = GEN8_PPAT(0, GEN8_PPAT_WB | GEN8_PPAT_LLC) |	/* for normal objects, no eLLC */
356 	      GEN8_PPAT(1, GEN8_PPAT_WC | GEN8_PPAT_LLCELLC) |	/* for something pointing to ptes? */
357 	      GEN8_PPAT(3, GEN8_PPAT_UC) |			/* Uncached objects, mostly for scanout */
358 	      GEN8_PPAT(4, GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(0)) |
359 	      GEN8_PPAT(5, GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(1)) |
360 	      GEN8_PPAT(6, GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(2)) |
361 	      GEN8_PPAT(7, GEN8_PPAT_WB | GEN8_PPAT_LLCELLC | GEN8_PPAT_AGE(3));
362 
363 	/* for scanout with eLLC */
364 	if (INTEL_GEN(i915) >= 9)
365 		pat |= GEN8_PPAT(2, GEN8_PPAT_WB | GEN8_PPAT_ELLC_OVERRIDE);
366 	else
367 		pat |= GEN8_PPAT(2, GEN8_PPAT_WT | GEN8_PPAT_LLCELLC);
368 
369 	intel_uncore_write(uncore, GEN8_PRIVATE_PAT_LO, lower_32_bits(pat));
370 	intel_uncore_write(uncore, GEN8_PRIVATE_PAT_HI, upper_32_bits(pat));
371 }
372 
373 static void chv_setup_private_ppat(struct intel_uncore *uncore)
374 {
375 	u64 pat;
376 
377 	/*
378 	 * Map WB on BDW to snooped on CHV.
379 	 *
380 	 * Only the snoop bit has meaning for CHV, the rest is
381 	 * ignored.
382 	 *
383 	 * The hardware will never snoop for certain types of accesses:
384 	 * - CPU GTT (GMADR->GGTT->no snoop->memory)
385 	 * - PPGTT page tables
386 	 * - some other special cycles
387 	 *
388 	 * As with BDW, we also need to consider the following for GT accesses:
389 	 * "For GGTT, there is NO pat_sel[2:0] from the entry,
390 	 * so RTL will always use the value corresponding to
391 	 * pat_sel = 000".
392 	 * Which means we must set the snoop bit in PAT entry 0
393 	 * in order to keep the global status page working.
394 	 */
395 
396 	pat = GEN8_PPAT(0, CHV_PPAT_SNOOP) |
397 	      GEN8_PPAT(1, 0) |
398 	      GEN8_PPAT(2, 0) |
399 	      GEN8_PPAT(3, 0) |
400 	      GEN8_PPAT(4, CHV_PPAT_SNOOP) |
401 	      GEN8_PPAT(5, CHV_PPAT_SNOOP) |
402 	      GEN8_PPAT(6, CHV_PPAT_SNOOP) |
403 	      GEN8_PPAT(7, CHV_PPAT_SNOOP);
404 
405 	intel_uncore_write(uncore, GEN8_PRIVATE_PAT_LO, lower_32_bits(pat));
406 	intel_uncore_write(uncore, GEN8_PRIVATE_PAT_HI, upper_32_bits(pat));
407 }
408 
409 void setup_private_pat(struct intel_uncore *uncore)
410 {
411 	struct drm_i915_private *i915 = uncore->i915;
412 
413 	GEM_BUG_ON(INTEL_GEN(i915) < 8);
414 
415 	if (INTEL_GEN(i915) >= 12)
416 		tgl_setup_private_ppat(uncore);
417 	else if (INTEL_GEN(i915) >= 10)
418 		cnl_setup_private_ppat(uncore);
419 	else if (IS_CHERRYVIEW(i915) || IS_GEN9_LP(i915))
420 		chv_setup_private_ppat(uncore);
421 	else
422 		bdw_setup_private_ppat(uncore);
423 }
424 
425 struct i915_vma *
426 __vm_create_scratch_for_read(struct i915_address_space *vm, unsigned long size)
427 {
428 	struct drm_i915_gem_object *obj;
429 	struct i915_vma *vma;
430 	int err;
431 
432 	obj = i915_gem_object_create_internal(vm->i915, PAGE_ALIGN(size));
433 	if (IS_ERR(obj))
434 		return ERR_CAST(obj);
435 
436 	i915_gem_object_set_cache_coherency(obj, I915_CACHING_CACHED);
437 
438 	vma = i915_vma_instance(obj, vm, NULL);
439 	if (IS_ERR(vma)) {
440 		i915_gem_object_put(obj);
441 		return vma;
442 	}
443 
444 	err = i915_vma_pin(vma, 0, 0,
445 			   i915_vma_is_ggtt(vma) ? PIN_GLOBAL : PIN_USER);
446 	if (err) {
447 		i915_vma_put(vma);
448 		return ERR_PTR(err);
449 	}
450 
451 	return vma;
452 }
453 
454 #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
455 #include "selftests/mock_gtt.c"
456 #endif
457