xref: /linux/drivers/gpu/drm/i915/i915_gpu_error.c (revision 3027ce13e04eee76539ca65c2cb1028a01c8c508)
1 /*
2  * Copyright (c) 2008 Intel Corporation
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining a
5  * copy of this software and associated documentation files (the "Software"),
6  * to deal in the Software without restriction, including without limitation
7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8  * and/or sell copies of the Software, and to permit persons to whom the
9  * Software is furnished to do so, subject to the following conditions:
10  *
11  * The above copyright notice and this permission notice (including the next
12  * paragraph) shall be included in all copies or substantial portions of the
13  * Software.
14  *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
21  * IN THE SOFTWARE.
22  *
23  * Authors:
24  *    Eric Anholt <eric@anholt.net>
25  *    Keith Packard <keithp@keithp.com>
26  *    Mika Kuoppala <mika.kuoppala@intel.com>
27  *
28  */
29 
30 #include <linux/ascii85.h>
31 #include <linux/highmem.h>
32 #include <linux/nmi.h>
33 #include <linux/pagevec.h>
34 #include <linux/scatterlist.h>
35 #include <linux/string_helpers.h>
36 #include <linux/utsname.h>
37 #include <linux/zlib.h>
38 
39 #include <drm/drm_cache.h>
40 #include <drm/drm_print.h>
41 
42 #include "display/intel_dmc.h"
43 #include "display/intel_overlay.h"
44 
45 #include "gem/i915_gem_context.h"
46 #include "gem/i915_gem_lmem.h"
47 #include "gt/intel_engine_regs.h"
48 #include "gt/intel_gt.h"
49 #include "gt/intel_gt_mcr.h"
50 #include "gt/intel_gt_pm.h"
51 #include "gt/intel_gt_regs.h"
52 #include "gt/uc/intel_guc_capture.h"
53 
54 #include "i915_driver.h"
55 #include "i915_drv.h"
56 #include "i915_gpu_error.h"
57 #include "i915_memcpy.h"
58 #include "i915_reg.h"
59 #include "i915_scatterlist.h"
60 #include "i915_sysfs.h"
61 #include "i915_utils.h"
62 
63 #define ALLOW_FAIL (__GFP_KSWAPD_RECLAIM | __GFP_RETRY_MAYFAIL | __GFP_NOWARN)
64 #define ATOMIC_MAYFAIL (GFP_ATOMIC | __GFP_NOWARN)
65 
66 static void __sg_set_buf(struct scatterlist *sg,
67 			 void *addr, unsigned int len, loff_t it)
68 {
69 	sg->page_link = (unsigned long)virt_to_page(addr);
70 	sg->offset = offset_in_page(addr);
71 	sg->length = len;
72 	sg->dma_address = it;
73 }
74 
75 static bool __i915_error_grow(struct drm_i915_error_state_buf *e, size_t len)
76 {
77 	if (!len)
78 		return false;
79 
80 	if (e->bytes + len + 1 <= e->size)
81 		return true;
82 
83 	if (e->bytes) {
84 		__sg_set_buf(e->cur++, e->buf, e->bytes, e->iter);
85 		e->iter += e->bytes;
86 		e->buf = NULL;
87 		e->bytes = 0;
88 	}
89 
90 	if (e->cur == e->end) {
91 		struct scatterlist *sgl;
92 
93 		sgl = (typeof(sgl))__get_free_page(ALLOW_FAIL);
94 		if (!sgl) {
95 			e->err = -ENOMEM;
96 			return false;
97 		}
98 
99 		if (e->cur) {
100 			e->cur->offset = 0;
101 			e->cur->length = 0;
102 			e->cur->page_link =
103 				(unsigned long)sgl | SG_CHAIN;
104 		} else {
105 			e->sgl = sgl;
106 		}
107 
108 		e->cur = sgl;
109 		e->end = sgl + SG_MAX_SINGLE_ALLOC - 1;
110 	}
111 
112 	e->size = ALIGN(len + 1, SZ_64K);
113 	e->buf = kmalloc(e->size, ALLOW_FAIL);
114 	if (!e->buf) {
115 		e->size = PAGE_ALIGN(len + 1);
116 		e->buf = kmalloc(e->size, GFP_KERNEL);
117 	}
118 	if (!e->buf) {
119 		e->err = -ENOMEM;
120 		return false;
121 	}
122 
123 	return true;
124 }
125 
126 __printf(2, 0)
127 static void i915_error_vprintf(struct drm_i915_error_state_buf *e,
128 			       const char *fmt, va_list args)
129 {
130 	va_list ap;
131 	int len;
132 
133 	if (e->err)
134 		return;
135 
136 	va_copy(ap, args);
137 	len = vsnprintf(NULL, 0, fmt, ap);
138 	va_end(ap);
139 	if (len <= 0) {
140 		e->err = len;
141 		return;
142 	}
143 
144 	if (!__i915_error_grow(e, len))
145 		return;
146 
147 	GEM_BUG_ON(e->bytes >= e->size);
148 	len = vscnprintf(e->buf + e->bytes, e->size - e->bytes, fmt, args);
149 	if (len < 0) {
150 		e->err = len;
151 		return;
152 	}
153 	e->bytes += len;
154 }
155 
156 static void i915_error_puts(struct drm_i915_error_state_buf *e, const char *str)
157 {
158 	unsigned len;
159 
160 	if (e->err || !str)
161 		return;
162 
163 	len = strlen(str);
164 	if (!__i915_error_grow(e, len))
165 		return;
166 
167 	GEM_BUG_ON(e->bytes + len > e->size);
168 	memcpy(e->buf + e->bytes, str, len);
169 	e->bytes += len;
170 }
171 
172 #define err_printf(e, ...) i915_error_printf(e, __VA_ARGS__)
173 #define err_puts(e, s) i915_error_puts(e, s)
174 
175 static void __i915_printfn_error(struct drm_printer *p, struct va_format *vaf)
176 {
177 	i915_error_vprintf(p->arg, vaf->fmt, *vaf->va);
178 }
179 
180 static inline struct drm_printer
181 i915_error_printer(struct drm_i915_error_state_buf *e)
182 {
183 	struct drm_printer p = {
184 		.printfn = __i915_printfn_error,
185 		.arg = e,
186 	};
187 	return p;
188 }
189 
190 /* single threaded page allocator with a reserved stash for emergencies */
191 static void pool_fini(struct folio_batch *fbatch)
192 {
193 	folio_batch_release(fbatch);
194 }
195 
196 static int pool_refill(struct folio_batch *fbatch, gfp_t gfp)
197 {
198 	while (folio_batch_space(fbatch)) {
199 		struct folio *folio;
200 
201 		folio = folio_alloc(gfp, 0);
202 		if (!folio)
203 			return -ENOMEM;
204 
205 		folio_batch_add(fbatch, folio);
206 	}
207 
208 	return 0;
209 }
210 
211 static int pool_init(struct folio_batch *fbatch, gfp_t gfp)
212 {
213 	int err;
214 
215 	folio_batch_init(fbatch);
216 
217 	err = pool_refill(fbatch, gfp);
218 	if (err)
219 		pool_fini(fbatch);
220 
221 	return err;
222 }
223 
224 static void *pool_alloc(struct folio_batch *fbatch, gfp_t gfp)
225 {
226 	struct folio *folio;
227 
228 	folio = folio_alloc(gfp, 0);
229 	if (!folio && folio_batch_count(fbatch))
230 		folio = fbatch->folios[--fbatch->nr];
231 
232 	return folio ? folio_address(folio) : NULL;
233 }
234 
235 static void pool_free(struct folio_batch *fbatch, void *addr)
236 {
237 	struct folio *folio = virt_to_folio(addr);
238 
239 	if (folio_batch_space(fbatch))
240 		folio_batch_add(fbatch, folio);
241 	else
242 		folio_put(folio);
243 }
244 
245 #ifdef CONFIG_DRM_I915_COMPRESS_ERROR
246 
247 struct i915_vma_compress {
248 	struct folio_batch pool;
249 	struct z_stream_s zstream;
250 	void *tmp;
251 };
252 
253 static bool compress_init(struct i915_vma_compress *c)
254 {
255 	struct z_stream_s *zstream = &c->zstream;
256 
257 	if (pool_init(&c->pool, ALLOW_FAIL))
258 		return false;
259 
260 	zstream->workspace =
261 		kmalloc(zlib_deflate_workspacesize(MAX_WBITS, MAX_MEM_LEVEL),
262 			ALLOW_FAIL);
263 	if (!zstream->workspace) {
264 		pool_fini(&c->pool);
265 		return false;
266 	}
267 
268 	c->tmp = NULL;
269 	if (i915_has_memcpy_from_wc())
270 		c->tmp = pool_alloc(&c->pool, ALLOW_FAIL);
271 
272 	return true;
273 }
274 
275 static bool compress_start(struct i915_vma_compress *c)
276 {
277 	struct z_stream_s *zstream = &c->zstream;
278 	void *workspace = zstream->workspace;
279 
280 	memset(zstream, 0, sizeof(*zstream));
281 	zstream->workspace = workspace;
282 
283 	return zlib_deflateInit(zstream, Z_DEFAULT_COMPRESSION) == Z_OK;
284 }
285 
286 static void *compress_next_page(struct i915_vma_compress *c,
287 				struct i915_vma_coredump *dst)
288 {
289 	void *page_addr;
290 	struct page *page;
291 
292 	page_addr = pool_alloc(&c->pool, ALLOW_FAIL);
293 	if (!page_addr)
294 		return ERR_PTR(-ENOMEM);
295 
296 	page = virt_to_page(page_addr);
297 	list_add_tail(&page->lru, &dst->page_list);
298 	return page_addr;
299 }
300 
301 static int compress_page(struct i915_vma_compress *c,
302 			 void *src,
303 			 struct i915_vma_coredump *dst,
304 			 bool wc)
305 {
306 	struct z_stream_s *zstream = &c->zstream;
307 
308 	zstream->next_in = src;
309 	if (wc && c->tmp && i915_memcpy_from_wc(c->tmp, src, PAGE_SIZE))
310 		zstream->next_in = c->tmp;
311 	zstream->avail_in = PAGE_SIZE;
312 
313 	do {
314 		if (zstream->avail_out == 0) {
315 			zstream->next_out = compress_next_page(c, dst);
316 			if (IS_ERR(zstream->next_out))
317 				return PTR_ERR(zstream->next_out);
318 
319 			zstream->avail_out = PAGE_SIZE;
320 		}
321 
322 		if (zlib_deflate(zstream, Z_NO_FLUSH) != Z_OK)
323 			return -EIO;
324 
325 		cond_resched();
326 	} while (zstream->avail_in);
327 
328 	/* Fallback to uncompressed if we increase size? */
329 	if (0 && zstream->total_out > zstream->total_in)
330 		return -E2BIG;
331 
332 	return 0;
333 }
334 
335 static int compress_flush(struct i915_vma_compress *c,
336 			  struct i915_vma_coredump *dst)
337 {
338 	struct z_stream_s *zstream = &c->zstream;
339 
340 	do {
341 		switch (zlib_deflate(zstream, Z_FINISH)) {
342 		case Z_OK: /* more space requested */
343 			zstream->next_out = compress_next_page(c, dst);
344 			if (IS_ERR(zstream->next_out))
345 				return PTR_ERR(zstream->next_out);
346 
347 			zstream->avail_out = PAGE_SIZE;
348 			break;
349 
350 		case Z_STREAM_END:
351 			goto end;
352 
353 		default: /* any error */
354 			return -EIO;
355 		}
356 	} while (1);
357 
358 end:
359 	memset(zstream->next_out, 0, zstream->avail_out);
360 	dst->unused = zstream->avail_out;
361 	return 0;
362 }
363 
364 static void compress_finish(struct i915_vma_compress *c)
365 {
366 	zlib_deflateEnd(&c->zstream);
367 }
368 
369 static void compress_fini(struct i915_vma_compress *c)
370 {
371 	kfree(c->zstream.workspace);
372 	if (c->tmp)
373 		pool_free(&c->pool, c->tmp);
374 	pool_fini(&c->pool);
375 }
376 
377 static void err_compression_marker(struct drm_i915_error_state_buf *m)
378 {
379 	err_puts(m, ":");
380 }
381 
382 #else
383 
384 struct i915_vma_compress {
385 	struct folio_batch pool;
386 };
387 
388 static bool compress_init(struct i915_vma_compress *c)
389 {
390 	return pool_init(&c->pool, ALLOW_FAIL) == 0;
391 }
392 
393 static bool compress_start(struct i915_vma_compress *c)
394 {
395 	return true;
396 }
397 
398 static int compress_page(struct i915_vma_compress *c,
399 			 void *src,
400 			 struct i915_vma_coredump *dst,
401 			 bool wc)
402 {
403 	void *ptr;
404 
405 	ptr = pool_alloc(&c->pool, ALLOW_FAIL);
406 	if (!ptr)
407 		return -ENOMEM;
408 
409 	if (!(wc && i915_memcpy_from_wc(ptr, src, PAGE_SIZE)))
410 		memcpy(ptr, src, PAGE_SIZE);
411 	list_add_tail(&virt_to_page(ptr)->lru, &dst->page_list);
412 	cond_resched();
413 
414 	return 0;
415 }
416 
417 static int compress_flush(struct i915_vma_compress *c,
418 			  struct i915_vma_coredump *dst)
419 {
420 	return 0;
421 }
422 
423 static void compress_finish(struct i915_vma_compress *c)
424 {
425 }
426 
427 static void compress_fini(struct i915_vma_compress *c)
428 {
429 	pool_fini(&c->pool);
430 }
431 
432 static void err_compression_marker(struct drm_i915_error_state_buf *m)
433 {
434 	err_puts(m, "~");
435 }
436 
437 #endif
438 
439 static void error_print_instdone(struct drm_i915_error_state_buf *m,
440 				 const struct intel_engine_coredump *ee)
441 {
442 	int slice;
443 	int subslice;
444 	int iter;
445 
446 	err_printf(m, "  INSTDONE: 0x%08x\n",
447 		   ee->instdone.instdone);
448 
449 	if (ee->engine->class != RENDER_CLASS || GRAPHICS_VER(m->i915) <= 3)
450 		return;
451 
452 	err_printf(m, "  SC_INSTDONE: 0x%08x\n",
453 		   ee->instdone.slice_common);
454 
455 	if (GRAPHICS_VER(m->i915) <= 6)
456 		return;
457 
458 	for_each_ss_steering(iter, ee->engine->gt, slice, subslice)
459 		err_printf(m, "  SAMPLER_INSTDONE[%d][%d]: 0x%08x\n",
460 			   slice, subslice,
461 			   ee->instdone.sampler[slice][subslice]);
462 
463 	for_each_ss_steering(iter, ee->engine->gt, slice, subslice)
464 		err_printf(m, "  ROW_INSTDONE[%d][%d]: 0x%08x\n",
465 			   slice, subslice,
466 			   ee->instdone.row[slice][subslice]);
467 
468 	if (GRAPHICS_VER(m->i915) < 12)
469 		return;
470 
471 	if (GRAPHICS_VER_FULL(m->i915) >= IP_VER(12, 55)) {
472 		for_each_ss_steering(iter, ee->engine->gt, slice, subslice)
473 			err_printf(m, "  GEOM_SVGUNIT_INSTDONE[%d][%d]: 0x%08x\n",
474 				   slice, subslice,
475 				   ee->instdone.geom_svg[slice][subslice]);
476 	}
477 
478 	err_printf(m, "  SC_INSTDONE_EXTRA: 0x%08x\n",
479 		   ee->instdone.slice_common_extra[0]);
480 	err_printf(m, "  SC_INSTDONE_EXTRA2: 0x%08x\n",
481 		   ee->instdone.slice_common_extra[1]);
482 }
483 
484 static void error_print_request(struct drm_i915_error_state_buf *m,
485 				const char *prefix,
486 				const struct i915_request_coredump *erq)
487 {
488 	if (!erq->seqno)
489 		return;
490 
491 	err_printf(m, "%s pid %d, seqno %8x:%08x%s%s, prio %d, head %08x, tail %08x\n",
492 		   prefix, erq->pid, erq->context, erq->seqno,
493 		   test_bit(DMA_FENCE_FLAG_SIGNALED_BIT,
494 			    &erq->flags) ? "!" : "",
495 		   test_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT,
496 			    &erq->flags) ? "+" : "",
497 		   erq->sched_attr.priority,
498 		   erq->head, erq->tail);
499 }
500 
501 static void error_print_context(struct drm_i915_error_state_buf *m,
502 				const char *header,
503 				const struct i915_gem_context_coredump *ctx)
504 {
505 	err_printf(m, "%s%s[%d] prio %d, guilty %d active %d, runtime total %lluns, avg %lluns\n",
506 		   header, ctx->comm, ctx->pid, ctx->sched_attr.priority,
507 		   ctx->guilty, ctx->active,
508 		   ctx->total_runtime, ctx->avg_runtime);
509 	err_printf(m, "  context timeline seqno %u\n", ctx->hwsp_seqno);
510 }
511 
512 static struct i915_vma_coredump *
513 __find_vma(struct i915_vma_coredump *vma, const char *name)
514 {
515 	while (vma) {
516 		if (strcmp(vma->name, name) == 0)
517 			return vma;
518 		vma = vma->next;
519 	}
520 
521 	return NULL;
522 }
523 
524 static struct i915_vma_coredump *
525 intel_gpu_error_find_batch(const struct intel_engine_coredump *ee)
526 {
527 	return __find_vma(ee->vma, "batch");
528 }
529 
530 static void error_print_engine(struct drm_i915_error_state_buf *m,
531 			       const struct intel_engine_coredump *ee)
532 {
533 	struct i915_vma_coredump *batch;
534 	int n;
535 
536 	err_printf(m, "%s command stream:\n", ee->engine->name);
537 	err_printf(m, "  CCID:  0x%08x\n", ee->ccid);
538 	err_printf(m, "  START: 0x%08x\n", ee->start);
539 	err_printf(m, "  HEAD:  0x%08x [0x%08x]\n", ee->head, ee->rq_head);
540 	err_printf(m, "  TAIL:  0x%08x [0x%08x, 0x%08x]\n",
541 		   ee->tail, ee->rq_post, ee->rq_tail);
542 	err_printf(m, "  CTL:   0x%08x\n", ee->ctl);
543 	err_printf(m, "  MODE:  0x%08x\n", ee->mode);
544 	err_printf(m, "  HWS:   0x%08x\n", ee->hws);
545 	err_printf(m, "  ACTHD: 0x%08x %08x\n",
546 		   (u32)(ee->acthd>>32), (u32)ee->acthd);
547 	err_printf(m, "  IPEIR: 0x%08x\n", ee->ipeir);
548 	err_printf(m, "  IPEHR: 0x%08x\n", ee->ipehr);
549 	err_printf(m, "  ESR:   0x%08x\n", ee->esr);
550 
551 	error_print_instdone(m, ee);
552 
553 	batch = intel_gpu_error_find_batch(ee);
554 	if (batch) {
555 		u64 start = batch->gtt_offset;
556 		u64 end = start + batch->gtt_size;
557 
558 		err_printf(m, "  batch: [0x%08x_%08x, 0x%08x_%08x]\n",
559 			   upper_32_bits(start), lower_32_bits(start),
560 			   upper_32_bits(end), lower_32_bits(end));
561 	}
562 	if (GRAPHICS_VER(m->i915) >= 4) {
563 		err_printf(m, "  BBADDR: 0x%08x_%08x\n",
564 			   (u32)(ee->bbaddr>>32), (u32)ee->bbaddr);
565 		err_printf(m, "  BB_STATE: 0x%08x\n", ee->bbstate);
566 		err_printf(m, "  INSTPS: 0x%08x\n", ee->instps);
567 	}
568 	err_printf(m, "  INSTPM: 0x%08x\n", ee->instpm);
569 	err_printf(m, "  FADDR: 0x%08x %08x\n", upper_32_bits(ee->faddr),
570 		   lower_32_bits(ee->faddr));
571 	if (GRAPHICS_VER(m->i915) >= 6) {
572 		err_printf(m, "  RC PSMI: 0x%08x\n", ee->rc_psmi);
573 		err_printf(m, "  FAULT_REG: 0x%08x\n", ee->fault_reg);
574 	}
575 	if (GRAPHICS_VER(m->i915) >= 11) {
576 		err_printf(m, "  NOPID: 0x%08x\n", ee->nopid);
577 		err_printf(m, "  EXCC: 0x%08x\n", ee->excc);
578 		err_printf(m, "  CMD_CCTL: 0x%08x\n", ee->cmd_cctl);
579 		err_printf(m, "  CSCMDOP: 0x%08x\n", ee->cscmdop);
580 		err_printf(m, "  CTX_SR_CTL: 0x%08x\n", ee->ctx_sr_ctl);
581 		err_printf(m, "  DMA_FADDR_HI: 0x%08x\n", ee->dma_faddr_hi);
582 		err_printf(m, "  DMA_FADDR_LO: 0x%08x\n", ee->dma_faddr_lo);
583 	}
584 	if (HAS_PPGTT(m->i915)) {
585 		err_printf(m, "  GFX_MODE: 0x%08x\n", ee->vm_info.gfx_mode);
586 
587 		if (GRAPHICS_VER(m->i915) >= 8) {
588 			int i;
589 			for (i = 0; i < 4; i++)
590 				err_printf(m, "  PDP%d: 0x%016llx\n",
591 					   i, ee->vm_info.pdp[i]);
592 		} else {
593 			err_printf(m, "  PP_DIR_BASE: 0x%08x\n",
594 				   ee->vm_info.pp_dir_base);
595 		}
596 	}
597 
598 	for (n = 0; n < ee->num_ports; n++) {
599 		err_printf(m, "  ELSP[%d]:", n);
600 		error_print_request(m, " ", &ee->execlist[n]);
601 	}
602 }
603 
604 void i915_error_printf(struct drm_i915_error_state_buf *e, const char *f, ...)
605 {
606 	va_list args;
607 
608 	va_start(args, f);
609 	i915_error_vprintf(e, f, args);
610 	va_end(args);
611 }
612 
613 static void intel_gpu_error_print_vma(struct drm_i915_error_state_buf *m,
614 				      const struct intel_engine_cs *engine,
615 				      const struct i915_vma_coredump *vma)
616 {
617 	char out[ASCII85_BUFSZ];
618 	struct page *page;
619 
620 	if (!vma)
621 		return;
622 
623 	err_printf(m, "%s --- %s = 0x%08x %08x\n",
624 		   engine ? engine->name : "global", vma->name,
625 		   upper_32_bits(vma->gtt_offset),
626 		   lower_32_bits(vma->gtt_offset));
627 
628 	if (vma->gtt_page_sizes > I915_GTT_PAGE_SIZE_4K)
629 		err_printf(m, "gtt_page_sizes = 0x%08x\n", vma->gtt_page_sizes);
630 
631 	err_compression_marker(m);
632 	list_for_each_entry(page, &vma->page_list, lru) {
633 		int i, len;
634 		const u32 *addr = page_address(page);
635 
636 		len = PAGE_SIZE;
637 		if (page == list_last_entry(&vma->page_list, typeof(*page), lru))
638 			len -= vma->unused;
639 		len = ascii85_encode_len(len);
640 
641 		for (i = 0; i < len; i++)
642 			err_puts(m, ascii85_encode(addr[i], out));
643 	}
644 	err_puts(m, "\n");
645 }
646 
647 static void err_print_capabilities(struct drm_i915_error_state_buf *m,
648 				   struct i915_gpu_coredump *error)
649 {
650 	struct drm_printer p = i915_error_printer(m);
651 
652 	intel_device_info_print(&error->device_info, &error->runtime_info, &p);
653 	intel_display_device_info_print(&error->display_device_info,
654 					&error->display_runtime_info, &p);
655 	intel_driver_caps_print(&error->driver_caps, &p);
656 }
657 
658 static void err_print_params(struct drm_i915_error_state_buf *m,
659 			     const struct i915_params *params)
660 {
661 	struct drm_printer p = i915_error_printer(m);
662 
663 	i915_params_dump(params, &p);
664 	intel_display_params_dump(m->i915, &p);
665 }
666 
667 static void err_print_pciid(struct drm_i915_error_state_buf *m,
668 			    struct drm_i915_private *i915)
669 {
670 	struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
671 
672 	err_printf(m, "PCI ID: 0x%04x\n", pdev->device);
673 	err_printf(m, "PCI Revision: 0x%02x\n", pdev->revision);
674 	err_printf(m, "PCI Subsystem: %04x:%04x\n",
675 		   pdev->subsystem_vendor,
676 		   pdev->subsystem_device);
677 }
678 
679 static void err_print_guc_ctb(struct drm_i915_error_state_buf *m,
680 			      const char *name,
681 			      const struct intel_ctb_coredump *ctb)
682 {
683 	if (!ctb->size)
684 		return;
685 
686 	err_printf(m, "GuC %s CTB: raw: 0x%08X, 0x%08X/%08X, cached: 0x%08X/%08X, desc = 0x%08X, buf = 0x%08X x 0x%08X\n",
687 		   name, ctb->raw_status, ctb->raw_head, ctb->raw_tail,
688 		   ctb->head, ctb->tail, ctb->desc_offset, ctb->cmds_offset, ctb->size);
689 }
690 
691 static void err_print_uc(struct drm_i915_error_state_buf *m,
692 			 const struct intel_uc_coredump *error_uc)
693 {
694 	struct drm_printer p = i915_error_printer(m);
695 
696 	intel_uc_fw_dump(&error_uc->guc_fw, &p);
697 	intel_uc_fw_dump(&error_uc->huc_fw, &p);
698 	err_printf(m, "GuC timestamp: 0x%08x\n", error_uc->guc.timestamp);
699 	intel_gpu_error_print_vma(m, NULL, error_uc->guc.vma_log);
700 	err_printf(m, "GuC CTB fence: %d\n", error_uc->guc.last_fence);
701 	err_print_guc_ctb(m, "Send", error_uc->guc.ctb + 0);
702 	err_print_guc_ctb(m, "Recv", error_uc->guc.ctb + 1);
703 	intel_gpu_error_print_vma(m, NULL, error_uc->guc.vma_ctb);
704 }
705 
706 static void err_free_sgl(struct scatterlist *sgl)
707 {
708 	while (sgl) {
709 		struct scatterlist *sg;
710 
711 		for (sg = sgl; !sg_is_chain(sg); sg++) {
712 			kfree(sg_virt(sg));
713 			if (sg_is_last(sg))
714 				break;
715 		}
716 
717 		sg = sg_is_last(sg) ? NULL : sg_chain_ptr(sg);
718 		free_page((unsigned long)sgl);
719 		sgl = sg;
720 	}
721 }
722 
723 static void err_print_gt_info(struct drm_i915_error_state_buf *m,
724 			      struct intel_gt_coredump *gt)
725 {
726 	struct drm_printer p = i915_error_printer(m);
727 
728 	intel_gt_info_print(&gt->info, &p);
729 	intel_sseu_print_topology(gt->_gt->i915, &gt->info.sseu, &p);
730 }
731 
732 static void err_print_gt_display(struct drm_i915_error_state_buf *m,
733 				 struct intel_gt_coredump *gt)
734 {
735 	err_printf(m, "IER: 0x%08x\n", gt->ier);
736 	err_printf(m, "DERRMR: 0x%08x\n", gt->derrmr);
737 }
738 
739 static void err_print_gt_global_nonguc(struct drm_i915_error_state_buf *m,
740 				       struct intel_gt_coredump *gt)
741 {
742 	int i;
743 
744 	err_printf(m, "GT awake: %s\n", str_yes_no(gt->awake));
745 	err_printf(m, "CS timestamp frequency: %u Hz, %d ns\n",
746 		   gt->clock_frequency, gt->clock_period_ns);
747 	err_printf(m, "EIR: 0x%08x\n", gt->eir);
748 	err_printf(m, "PGTBL_ER: 0x%08x\n", gt->pgtbl_er);
749 
750 	for (i = 0; i < gt->ngtier; i++)
751 		err_printf(m, "GTIER[%d]: 0x%08x\n", i, gt->gtier[i]);
752 }
753 
754 static void err_print_gt_global(struct drm_i915_error_state_buf *m,
755 				struct intel_gt_coredump *gt)
756 {
757 	err_printf(m, "FORCEWAKE: 0x%08x\n", gt->forcewake);
758 
759 	if (IS_GRAPHICS_VER(m->i915, 6, 11)) {
760 		err_printf(m, "ERROR: 0x%08x\n", gt->error);
761 		err_printf(m, "DONE_REG: 0x%08x\n", gt->done_reg);
762 	}
763 
764 	if (GRAPHICS_VER(m->i915) >= 8)
765 		err_printf(m, "FAULT_TLB_DATA: 0x%08x 0x%08x\n",
766 			   gt->fault_data1, gt->fault_data0);
767 
768 	if (GRAPHICS_VER(m->i915) == 7)
769 		err_printf(m, "ERR_INT: 0x%08x\n", gt->err_int);
770 
771 	if (IS_GRAPHICS_VER(m->i915, 8, 11))
772 		err_printf(m, "GTT_CACHE_EN: 0x%08x\n", gt->gtt_cache);
773 
774 	if (GRAPHICS_VER(m->i915) == 12)
775 		err_printf(m, "AUX_ERR_DBG: 0x%08x\n", gt->aux_err);
776 
777 	if (GRAPHICS_VER(m->i915) >= 12) {
778 		int i;
779 
780 		for (i = 0; i < I915_MAX_SFC; i++) {
781 			/*
782 			 * SFC_DONE resides in the VD forcewake domain, so it
783 			 * only exists if the corresponding VCS engine is
784 			 * present.
785 			 */
786 			if ((gt->_gt->info.sfc_mask & BIT(i)) == 0 ||
787 			    !HAS_ENGINE(gt->_gt, _VCS(i * 2)))
788 				continue;
789 
790 			err_printf(m, "  SFC_DONE[%d]: 0x%08x\n", i,
791 				   gt->sfc_done[i]);
792 		}
793 
794 		err_printf(m, "  GAM_DONE: 0x%08x\n", gt->gam_done);
795 	}
796 }
797 
798 static void err_print_gt_fences(struct drm_i915_error_state_buf *m,
799 				struct intel_gt_coredump *gt)
800 {
801 	int i;
802 
803 	for (i = 0; i < gt->nfence; i++)
804 		err_printf(m, "  fence[%d] = %08llx\n", i, gt->fence[i]);
805 }
806 
807 static void err_print_gt_engines(struct drm_i915_error_state_buf *m,
808 				 struct intel_gt_coredump *gt)
809 {
810 	const struct intel_engine_coredump *ee;
811 
812 	for (ee = gt->engine; ee; ee = ee->next) {
813 		const struct i915_vma_coredump *vma;
814 
815 		if (gt->uc && gt->uc->guc.is_guc_capture) {
816 			if (ee->guc_capture_node)
817 				intel_guc_capture_print_engine_node(m, ee);
818 			else
819 				err_printf(m, "  Missing GuC capture node for %s\n",
820 					   ee->engine->name);
821 		} else {
822 			error_print_engine(m, ee);
823 		}
824 
825 		err_printf(m, "  hung: %u\n", ee->hung);
826 		err_printf(m, "  engine reset count: %u\n", ee->reset_count);
827 		error_print_context(m, "  Active context: ", &ee->context);
828 
829 		for (vma = ee->vma; vma; vma = vma->next)
830 			intel_gpu_error_print_vma(m, ee->engine, vma);
831 	}
832 
833 }
834 
835 static void __err_print_to_sgl(struct drm_i915_error_state_buf *m,
836 			       struct i915_gpu_coredump *error)
837 {
838 	const struct intel_engine_coredump *ee;
839 	struct timespec64 ts;
840 
841 	if (*error->error_msg)
842 		err_printf(m, "%s\n", error->error_msg);
843 	err_printf(m, "Kernel: %s %s\n",
844 		   init_utsname()->release,
845 		   init_utsname()->machine);
846 	err_printf(m, "Driver: %s\n", DRIVER_DATE);
847 	ts = ktime_to_timespec64(error->time);
848 	err_printf(m, "Time: %lld s %ld us\n",
849 		   (s64)ts.tv_sec, ts.tv_nsec / NSEC_PER_USEC);
850 	ts = ktime_to_timespec64(error->boottime);
851 	err_printf(m, "Boottime: %lld s %ld us\n",
852 		   (s64)ts.tv_sec, ts.tv_nsec / NSEC_PER_USEC);
853 	ts = ktime_to_timespec64(error->uptime);
854 	err_printf(m, "Uptime: %lld s %ld us\n",
855 		   (s64)ts.tv_sec, ts.tv_nsec / NSEC_PER_USEC);
856 	err_printf(m, "Capture: %lu jiffies; %d ms ago\n",
857 		   error->capture, jiffies_to_msecs(jiffies - error->capture));
858 
859 	for (ee = error->gt ? error->gt->engine : NULL; ee; ee = ee->next)
860 		err_printf(m, "Active process (on ring %s): %s [%d]\n",
861 			   ee->engine->name,
862 			   ee->context.comm,
863 			   ee->context.pid);
864 
865 	err_printf(m, "Reset count: %u\n", error->reset_count);
866 	err_printf(m, "Suspend count: %u\n", error->suspend_count);
867 	err_printf(m, "Platform: %s\n", intel_platform_name(error->device_info.platform));
868 	err_printf(m, "Subplatform: 0x%x\n",
869 		   intel_subplatform(&error->runtime_info,
870 				     error->device_info.platform));
871 	err_print_pciid(m, m->i915);
872 
873 	err_printf(m, "IOMMU enabled?: %d\n", error->iommu);
874 
875 	intel_dmc_print_error_state(m, m->i915);
876 
877 	err_printf(m, "RPM wakelock: %s\n", str_yes_no(error->wakelock));
878 	err_printf(m, "PM suspended: %s\n", str_yes_no(error->suspended));
879 
880 	if (error->gt) {
881 		bool print_guc_capture = false;
882 
883 		if (error->gt->uc && error->gt->uc->guc.is_guc_capture)
884 			print_guc_capture = true;
885 
886 		err_print_gt_display(m, error->gt);
887 		err_print_gt_global_nonguc(m, error->gt);
888 		err_print_gt_fences(m, error->gt);
889 
890 		/*
891 		 * GuC dumped global, eng-class and eng-instance registers together
892 		 * as part of engine state dump so we print in err_print_gt_engines
893 		 */
894 		if (!print_guc_capture)
895 			err_print_gt_global(m, error->gt);
896 
897 		err_print_gt_engines(m, error->gt);
898 
899 		if (error->gt->uc)
900 			err_print_uc(m, error->gt->uc);
901 
902 		err_print_gt_info(m, error->gt);
903 	}
904 
905 	if (error->overlay)
906 		intel_overlay_print_error_state(m, error->overlay);
907 
908 	err_print_capabilities(m, error);
909 	err_print_params(m, &error->params);
910 }
911 
912 static int err_print_to_sgl(struct i915_gpu_coredump *error)
913 {
914 	struct drm_i915_error_state_buf m;
915 
916 	if (IS_ERR(error))
917 		return PTR_ERR(error);
918 
919 	if (READ_ONCE(error->sgl))
920 		return 0;
921 
922 	memset(&m, 0, sizeof(m));
923 	m.i915 = error->i915;
924 
925 	__err_print_to_sgl(&m, error);
926 
927 	if (m.buf) {
928 		__sg_set_buf(m.cur++, m.buf, m.bytes, m.iter);
929 		m.bytes = 0;
930 		m.buf = NULL;
931 	}
932 	if (m.cur) {
933 		GEM_BUG_ON(m.end < m.cur);
934 		sg_mark_end(m.cur - 1);
935 	}
936 	GEM_BUG_ON(m.sgl && !m.cur);
937 
938 	if (m.err) {
939 		err_free_sgl(m.sgl);
940 		return m.err;
941 	}
942 
943 	if (cmpxchg(&error->sgl, NULL, m.sgl))
944 		err_free_sgl(m.sgl);
945 
946 	return 0;
947 }
948 
949 ssize_t i915_gpu_coredump_copy_to_buffer(struct i915_gpu_coredump *error,
950 					 char *buf, loff_t off, size_t rem)
951 {
952 	struct scatterlist *sg;
953 	size_t count;
954 	loff_t pos;
955 	int err;
956 
957 	if (!error || !rem)
958 		return 0;
959 
960 	err = err_print_to_sgl(error);
961 	if (err)
962 		return err;
963 
964 	sg = READ_ONCE(error->fit);
965 	if (!sg || off < sg->dma_address)
966 		sg = error->sgl;
967 	if (!sg)
968 		return 0;
969 
970 	pos = sg->dma_address;
971 	count = 0;
972 	do {
973 		size_t len, start;
974 
975 		if (sg_is_chain(sg)) {
976 			sg = sg_chain_ptr(sg);
977 			GEM_BUG_ON(sg_is_chain(sg));
978 		}
979 
980 		len = sg->length;
981 		if (pos + len <= off) {
982 			pos += len;
983 			continue;
984 		}
985 
986 		start = sg->offset;
987 		if (pos < off) {
988 			GEM_BUG_ON(off - pos > len);
989 			len -= off - pos;
990 			start += off - pos;
991 			pos = off;
992 		}
993 
994 		len = min(len, rem);
995 		GEM_BUG_ON(!len || len > sg->length);
996 
997 		memcpy(buf, page_address(sg_page(sg)) + start, len);
998 
999 		count += len;
1000 		pos += len;
1001 
1002 		buf += len;
1003 		rem -= len;
1004 		if (!rem) {
1005 			WRITE_ONCE(error->fit, sg);
1006 			break;
1007 		}
1008 	} while (!sg_is_last(sg++));
1009 
1010 	return count;
1011 }
1012 
1013 static void i915_vma_coredump_free(struct i915_vma_coredump *vma)
1014 {
1015 	while (vma) {
1016 		struct i915_vma_coredump *next = vma->next;
1017 		struct page *page, *n;
1018 
1019 		list_for_each_entry_safe(page, n, &vma->page_list, lru) {
1020 			list_del_init(&page->lru);
1021 			__free_page(page);
1022 		}
1023 
1024 		kfree(vma);
1025 		vma = next;
1026 	}
1027 }
1028 
1029 static void cleanup_params(struct i915_gpu_coredump *error)
1030 {
1031 	i915_params_free(&error->params);
1032 	intel_display_params_free(&error->display_params);
1033 }
1034 
1035 static void cleanup_uc(struct intel_uc_coredump *uc)
1036 {
1037 	kfree(uc->guc_fw.file_selected.path);
1038 	kfree(uc->huc_fw.file_selected.path);
1039 	kfree(uc->guc_fw.file_wanted.path);
1040 	kfree(uc->huc_fw.file_wanted.path);
1041 	i915_vma_coredump_free(uc->guc.vma_log);
1042 	i915_vma_coredump_free(uc->guc.vma_ctb);
1043 
1044 	kfree(uc);
1045 }
1046 
1047 static void cleanup_gt(struct intel_gt_coredump *gt)
1048 {
1049 	while (gt->engine) {
1050 		struct intel_engine_coredump *ee = gt->engine;
1051 
1052 		gt->engine = ee->next;
1053 
1054 		i915_vma_coredump_free(ee->vma);
1055 		intel_guc_capture_free_node(ee);
1056 		kfree(ee);
1057 	}
1058 
1059 	if (gt->uc)
1060 		cleanup_uc(gt->uc);
1061 
1062 	kfree(gt);
1063 }
1064 
1065 void __i915_gpu_coredump_free(struct kref *error_ref)
1066 {
1067 	struct i915_gpu_coredump *error =
1068 		container_of(error_ref, typeof(*error), ref);
1069 
1070 	while (error->gt) {
1071 		struct intel_gt_coredump *gt = error->gt;
1072 
1073 		error->gt = gt->next;
1074 		cleanup_gt(gt);
1075 	}
1076 
1077 	kfree(error->overlay);
1078 
1079 	cleanup_params(error);
1080 
1081 	err_free_sgl(error->sgl);
1082 	kfree(error);
1083 }
1084 
1085 static struct i915_vma_coredump *
1086 i915_vma_coredump_create(const struct intel_gt *gt,
1087 			 const struct i915_vma_resource *vma_res,
1088 			 struct i915_vma_compress *compress,
1089 			 const char *name)
1090 
1091 {
1092 	struct i915_ggtt *ggtt = gt->ggtt;
1093 	const u64 slot = ggtt->error_capture.start;
1094 	struct i915_vma_coredump *dst;
1095 	struct sgt_iter iter;
1096 	int ret;
1097 
1098 	might_sleep();
1099 
1100 	if (!vma_res || !vma_res->bi.pages || !compress)
1101 		return NULL;
1102 
1103 	dst = kmalloc(sizeof(*dst), ALLOW_FAIL);
1104 	if (!dst)
1105 		return NULL;
1106 
1107 	if (!compress_start(compress)) {
1108 		kfree(dst);
1109 		return NULL;
1110 	}
1111 
1112 	INIT_LIST_HEAD(&dst->page_list);
1113 	strcpy(dst->name, name);
1114 	dst->next = NULL;
1115 
1116 	dst->gtt_offset = vma_res->start;
1117 	dst->gtt_size = vma_res->node_size;
1118 	dst->gtt_page_sizes = vma_res->page_sizes_gtt;
1119 	dst->unused = 0;
1120 
1121 	ret = -EINVAL;
1122 	if (drm_mm_node_allocated(&ggtt->error_capture)) {
1123 		void __iomem *s;
1124 		dma_addr_t dma;
1125 
1126 		for_each_sgt_daddr(dma, iter, vma_res->bi.pages) {
1127 			mutex_lock(&ggtt->error_mutex);
1128 			if (ggtt->vm.raw_insert_page)
1129 				ggtt->vm.raw_insert_page(&ggtt->vm, dma, slot,
1130 							 i915_gem_get_pat_index(gt->i915,
1131 										I915_CACHE_NONE),
1132 							 0);
1133 			else
1134 				ggtt->vm.insert_page(&ggtt->vm, dma, slot,
1135 						     i915_gem_get_pat_index(gt->i915,
1136 									    I915_CACHE_NONE),
1137 						     0);
1138 			mb();
1139 
1140 			s = io_mapping_map_wc(&ggtt->iomap, slot, PAGE_SIZE);
1141 			ret = compress_page(compress,
1142 					    (void  __force *)s, dst,
1143 					    true);
1144 			io_mapping_unmap(s);
1145 
1146 			mb();
1147 			ggtt->vm.clear_range(&ggtt->vm, slot, PAGE_SIZE);
1148 			mutex_unlock(&ggtt->error_mutex);
1149 			if (ret)
1150 				break;
1151 		}
1152 	} else if (vma_res->bi.lmem) {
1153 		struct intel_memory_region *mem = vma_res->mr;
1154 		dma_addr_t dma;
1155 
1156 		for_each_sgt_daddr(dma, iter, vma_res->bi.pages) {
1157 			dma_addr_t offset = dma - mem->region.start;
1158 			void __iomem *s;
1159 
1160 			if (offset + PAGE_SIZE > resource_size(&mem->io)) {
1161 				ret = -EINVAL;
1162 				break;
1163 			}
1164 
1165 			s = io_mapping_map_wc(&mem->iomap, offset, PAGE_SIZE);
1166 			ret = compress_page(compress,
1167 					    (void __force *)s, dst,
1168 					    true);
1169 			io_mapping_unmap(s);
1170 			if (ret)
1171 				break;
1172 		}
1173 	} else {
1174 		struct page *page;
1175 
1176 		for_each_sgt_page(page, iter, vma_res->bi.pages) {
1177 			void *s;
1178 
1179 			drm_clflush_pages(&page, 1);
1180 
1181 			s = kmap_local_page(page);
1182 			ret = compress_page(compress, s, dst, false);
1183 			kunmap_local(s);
1184 
1185 			drm_clflush_pages(&page, 1);
1186 
1187 			if (ret)
1188 				break;
1189 		}
1190 	}
1191 
1192 	if (ret || compress_flush(compress, dst)) {
1193 		struct page *page, *n;
1194 
1195 		list_for_each_entry_safe_reverse(page, n, &dst->page_list, lru) {
1196 			list_del_init(&page->lru);
1197 			pool_free(&compress->pool, page_address(page));
1198 		}
1199 
1200 		kfree(dst);
1201 		dst = NULL;
1202 	}
1203 	compress_finish(compress);
1204 
1205 	return dst;
1206 }
1207 
1208 static void gt_record_fences(struct intel_gt_coredump *gt)
1209 {
1210 	struct i915_ggtt *ggtt = gt->_gt->ggtt;
1211 	struct intel_uncore *uncore = gt->_gt->uncore;
1212 	int i;
1213 
1214 	if (GRAPHICS_VER(uncore->i915) >= 6) {
1215 		for (i = 0; i < ggtt->num_fences; i++)
1216 			gt->fence[i] =
1217 				intel_uncore_read64(uncore,
1218 						    FENCE_REG_GEN6_LO(i));
1219 	} else if (GRAPHICS_VER(uncore->i915) >= 4) {
1220 		for (i = 0; i < ggtt->num_fences; i++)
1221 			gt->fence[i] =
1222 				intel_uncore_read64(uncore,
1223 						    FENCE_REG_965_LO(i));
1224 	} else {
1225 		for (i = 0; i < ggtt->num_fences; i++)
1226 			gt->fence[i] =
1227 				intel_uncore_read(uncore, FENCE_REG(i));
1228 	}
1229 	gt->nfence = i;
1230 }
1231 
1232 static void engine_record_registers(struct intel_engine_coredump *ee)
1233 {
1234 	const struct intel_engine_cs *engine = ee->engine;
1235 	struct drm_i915_private *i915 = engine->i915;
1236 
1237 	if (GRAPHICS_VER(i915) >= 6) {
1238 		ee->rc_psmi = ENGINE_READ(engine, RING_PSMI_CTL);
1239 
1240 		/*
1241 		 * For the media GT, this ring fault register is not replicated,
1242 		 * so don't do multicast/replicated register read/write
1243 		 * operation on it.
1244 		 */
1245 		if (MEDIA_VER(i915) >= 13 && engine->gt->type == GT_MEDIA)
1246 			ee->fault_reg = intel_uncore_read(engine->uncore,
1247 							  XELPMP_RING_FAULT_REG);
1248 		else if (GRAPHICS_VER_FULL(i915) >= IP_VER(12, 55))
1249 			ee->fault_reg = intel_gt_mcr_read_any(engine->gt,
1250 							      XEHP_RING_FAULT_REG);
1251 		else if (GRAPHICS_VER(i915) >= 12)
1252 			ee->fault_reg = intel_uncore_read(engine->uncore,
1253 							  GEN12_RING_FAULT_REG);
1254 		else if (GRAPHICS_VER(i915) >= 8)
1255 			ee->fault_reg = intel_uncore_read(engine->uncore,
1256 							  GEN8_RING_FAULT_REG);
1257 		else
1258 			ee->fault_reg = GEN6_RING_FAULT_REG_READ(engine);
1259 	}
1260 
1261 	if (GRAPHICS_VER(i915) >= 4) {
1262 		ee->esr = ENGINE_READ(engine, RING_ESR);
1263 		ee->faddr = ENGINE_READ(engine, RING_DMA_FADD);
1264 		ee->ipeir = ENGINE_READ(engine, RING_IPEIR);
1265 		ee->ipehr = ENGINE_READ(engine, RING_IPEHR);
1266 		ee->instps = ENGINE_READ(engine, RING_INSTPS);
1267 		ee->bbaddr = ENGINE_READ(engine, RING_BBADDR);
1268 		ee->ccid = ENGINE_READ(engine, CCID);
1269 		if (GRAPHICS_VER(i915) >= 8) {
1270 			ee->faddr |= (u64)ENGINE_READ(engine, RING_DMA_FADD_UDW) << 32;
1271 			ee->bbaddr |= (u64)ENGINE_READ(engine, RING_BBADDR_UDW) << 32;
1272 		}
1273 		ee->bbstate = ENGINE_READ(engine, RING_BBSTATE);
1274 	} else {
1275 		ee->faddr = ENGINE_READ(engine, DMA_FADD_I8XX);
1276 		ee->ipeir = ENGINE_READ(engine, IPEIR);
1277 		ee->ipehr = ENGINE_READ(engine, IPEHR);
1278 	}
1279 
1280 	if (GRAPHICS_VER(i915) >= 11) {
1281 		ee->cmd_cctl = ENGINE_READ(engine, RING_CMD_CCTL);
1282 		ee->cscmdop = ENGINE_READ(engine, RING_CSCMDOP);
1283 		ee->ctx_sr_ctl = ENGINE_READ(engine, RING_CTX_SR_CTL);
1284 		ee->dma_faddr_hi = ENGINE_READ(engine, RING_DMA_FADD_UDW);
1285 		ee->dma_faddr_lo = ENGINE_READ(engine, RING_DMA_FADD);
1286 		ee->nopid = ENGINE_READ(engine, RING_NOPID);
1287 		ee->excc = ENGINE_READ(engine, RING_EXCC);
1288 	}
1289 
1290 	intel_engine_get_instdone(engine, &ee->instdone);
1291 
1292 	ee->instpm = ENGINE_READ(engine, RING_INSTPM);
1293 	ee->acthd = intel_engine_get_active_head(engine);
1294 	ee->start = ENGINE_READ(engine, RING_START);
1295 	ee->head = ENGINE_READ(engine, RING_HEAD);
1296 	ee->tail = ENGINE_READ(engine, RING_TAIL);
1297 	ee->ctl = ENGINE_READ(engine, RING_CTL);
1298 	if (GRAPHICS_VER(i915) > 2)
1299 		ee->mode = ENGINE_READ(engine, RING_MI_MODE);
1300 
1301 	if (!HWS_NEEDS_PHYSICAL(i915)) {
1302 		i915_reg_t mmio;
1303 
1304 		if (GRAPHICS_VER(i915) == 7) {
1305 			switch (engine->id) {
1306 			default:
1307 				MISSING_CASE(engine->id);
1308 				fallthrough;
1309 			case RCS0:
1310 				mmio = RENDER_HWS_PGA_GEN7;
1311 				break;
1312 			case BCS0:
1313 				mmio = BLT_HWS_PGA_GEN7;
1314 				break;
1315 			case VCS0:
1316 				mmio = BSD_HWS_PGA_GEN7;
1317 				break;
1318 			case VECS0:
1319 				mmio = VEBOX_HWS_PGA_GEN7;
1320 				break;
1321 			}
1322 		} else if (GRAPHICS_VER(engine->i915) == 6) {
1323 			mmio = RING_HWS_PGA_GEN6(engine->mmio_base);
1324 		} else {
1325 			/* XXX: gen8 returns to sanity */
1326 			mmio = RING_HWS_PGA(engine->mmio_base);
1327 		}
1328 
1329 		ee->hws = intel_uncore_read(engine->uncore, mmio);
1330 	}
1331 
1332 	ee->reset_count = i915_reset_engine_count(&i915->gpu_error, engine);
1333 
1334 	if (HAS_PPGTT(i915)) {
1335 		int i;
1336 
1337 		ee->vm_info.gfx_mode = ENGINE_READ(engine, RING_MODE_GEN7);
1338 
1339 		if (GRAPHICS_VER(i915) == 6) {
1340 			ee->vm_info.pp_dir_base =
1341 				ENGINE_READ(engine, RING_PP_DIR_BASE_READ);
1342 		} else if (GRAPHICS_VER(i915) == 7) {
1343 			ee->vm_info.pp_dir_base =
1344 				ENGINE_READ(engine, RING_PP_DIR_BASE);
1345 		} else if (GRAPHICS_VER(i915) >= 8) {
1346 			u32 base = engine->mmio_base;
1347 
1348 			for (i = 0; i < 4; i++) {
1349 				ee->vm_info.pdp[i] =
1350 					intel_uncore_read(engine->uncore,
1351 							  GEN8_RING_PDP_UDW(base, i));
1352 				ee->vm_info.pdp[i] <<= 32;
1353 				ee->vm_info.pdp[i] |=
1354 					intel_uncore_read(engine->uncore,
1355 							  GEN8_RING_PDP_LDW(base, i));
1356 			}
1357 		}
1358 	}
1359 }
1360 
1361 static void record_request(const struct i915_request *request,
1362 			   struct i915_request_coredump *erq)
1363 {
1364 	erq->flags = request->fence.flags;
1365 	erq->context = request->fence.context;
1366 	erq->seqno = request->fence.seqno;
1367 	erq->sched_attr = request->sched.attr;
1368 	erq->head = request->head;
1369 	erq->tail = request->tail;
1370 
1371 	erq->pid = 0;
1372 	rcu_read_lock();
1373 	if (!intel_context_is_closed(request->context)) {
1374 		const struct i915_gem_context *ctx;
1375 
1376 		ctx = rcu_dereference(request->context->gem_context);
1377 		if (ctx)
1378 			erq->pid = pid_nr(ctx->pid);
1379 	}
1380 	rcu_read_unlock();
1381 }
1382 
1383 static void engine_record_execlists(struct intel_engine_coredump *ee)
1384 {
1385 	const struct intel_engine_execlists * const el = &ee->engine->execlists;
1386 	struct i915_request * const *port = el->active;
1387 	unsigned int n = 0;
1388 
1389 	while (*port)
1390 		record_request(*port++, &ee->execlist[n++]);
1391 
1392 	ee->num_ports = n;
1393 }
1394 
1395 static bool record_context(struct i915_gem_context_coredump *e,
1396 			   struct intel_context *ce)
1397 {
1398 	struct i915_gem_context *ctx;
1399 	struct task_struct *task;
1400 	bool simulated;
1401 
1402 	rcu_read_lock();
1403 	ctx = rcu_dereference(ce->gem_context);
1404 	if (ctx && !kref_get_unless_zero(&ctx->ref))
1405 		ctx = NULL;
1406 	rcu_read_unlock();
1407 	if (!ctx)
1408 		return true;
1409 
1410 	rcu_read_lock();
1411 	task = pid_task(ctx->pid, PIDTYPE_PID);
1412 	if (task) {
1413 		strcpy(e->comm, task->comm);
1414 		e->pid = task->pid;
1415 	}
1416 	rcu_read_unlock();
1417 
1418 	e->sched_attr = ctx->sched;
1419 	e->guilty = atomic_read(&ctx->guilty_count);
1420 	e->active = atomic_read(&ctx->active_count);
1421 	e->hwsp_seqno = (ce->timeline && ce->timeline->hwsp_seqno) ?
1422 				*ce->timeline->hwsp_seqno : ~0U;
1423 
1424 	e->total_runtime = intel_context_get_total_runtime_ns(ce);
1425 	e->avg_runtime = intel_context_get_avg_runtime_ns(ce);
1426 
1427 	simulated = i915_gem_context_no_error_capture(ctx);
1428 
1429 	i915_gem_context_put(ctx);
1430 	return simulated;
1431 }
1432 
1433 struct intel_engine_capture_vma {
1434 	struct intel_engine_capture_vma *next;
1435 	struct i915_vma_resource *vma_res;
1436 	char name[16];
1437 	bool lockdep_cookie;
1438 };
1439 
1440 static struct intel_engine_capture_vma *
1441 capture_vma_snapshot(struct intel_engine_capture_vma *next,
1442 		     struct i915_vma_resource *vma_res,
1443 		     gfp_t gfp, const char *name)
1444 {
1445 	struct intel_engine_capture_vma *c;
1446 
1447 	if (!vma_res)
1448 		return next;
1449 
1450 	c = kmalloc(sizeof(*c), gfp);
1451 	if (!c)
1452 		return next;
1453 
1454 	if (!i915_vma_resource_hold(vma_res, &c->lockdep_cookie)) {
1455 		kfree(c);
1456 		return next;
1457 	}
1458 
1459 	strcpy(c->name, name);
1460 	c->vma_res = i915_vma_resource_get(vma_res);
1461 
1462 	c->next = next;
1463 	return c;
1464 }
1465 
1466 static struct intel_engine_capture_vma *
1467 capture_vma(struct intel_engine_capture_vma *next,
1468 	    struct i915_vma *vma,
1469 	    const char *name,
1470 	    gfp_t gfp)
1471 {
1472 	if (!vma)
1473 		return next;
1474 
1475 	/*
1476 	 * If the vma isn't pinned, then the vma should be snapshotted
1477 	 * to a struct i915_vma_snapshot at command submission time.
1478 	 * Not here.
1479 	 */
1480 	if (GEM_WARN_ON(!i915_vma_is_pinned(vma)))
1481 		return next;
1482 
1483 	next = capture_vma_snapshot(next, vma->resource, gfp, name);
1484 
1485 	return next;
1486 }
1487 
1488 static struct intel_engine_capture_vma *
1489 capture_user(struct intel_engine_capture_vma *capture,
1490 	     const struct i915_request *rq,
1491 	     gfp_t gfp)
1492 {
1493 	struct i915_capture_list *c;
1494 
1495 	for (c = rq->capture_list; c; c = c->next)
1496 		capture = capture_vma_snapshot(capture, c->vma_res, gfp,
1497 					       "user");
1498 
1499 	return capture;
1500 }
1501 
1502 static void add_vma(struct intel_engine_coredump *ee,
1503 		    struct i915_vma_coredump *vma)
1504 {
1505 	if (vma) {
1506 		vma->next = ee->vma;
1507 		ee->vma = vma;
1508 	}
1509 }
1510 
1511 static struct i915_vma_coredump *
1512 create_vma_coredump(const struct intel_gt *gt, struct i915_vma *vma,
1513 		    const char *name, struct i915_vma_compress *compress)
1514 {
1515 	struct i915_vma_coredump *ret = NULL;
1516 	struct i915_vma_resource *vma_res;
1517 	bool lockdep_cookie;
1518 
1519 	if (!vma)
1520 		return NULL;
1521 
1522 	vma_res = vma->resource;
1523 
1524 	if (i915_vma_resource_hold(vma_res, &lockdep_cookie)) {
1525 		ret = i915_vma_coredump_create(gt, vma_res, compress, name);
1526 		i915_vma_resource_unhold(vma_res, lockdep_cookie);
1527 	}
1528 
1529 	return ret;
1530 }
1531 
1532 static void add_vma_coredump(struct intel_engine_coredump *ee,
1533 			     const struct intel_gt *gt,
1534 			     struct i915_vma *vma,
1535 			     const char *name,
1536 			     struct i915_vma_compress *compress)
1537 {
1538 	add_vma(ee, create_vma_coredump(gt, vma, name, compress));
1539 }
1540 
1541 struct intel_engine_coredump *
1542 intel_engine_coredump_alloc(struct intel_engine_cs *engine, gfp_t gfp, u32 dump_flags)
1543 {
1544 	struct intel_engine_coredump *ee;
1545 
1546 	ee = kzalloc(sizeof(*ee), gfp);
1547 	if (!ee)
1548 		return NULL;
1549 
1550 	ee->engine = engine;
1551 
1552 	if (!(dump_flags & CORE_DUMP_FLAG_IS_GUC_CAPTURE)) {
1553 		engine_record_registers(ee);
1554 		engine_record_execlists(ee);
1555 	}
1556 
1557 	return ee;
1558 }
1559 
1560 static struct intel_engine_capture_vma *
1561 engine_coredump_add_context(struct intel_engine_coredump *ee,
1562 			    struct intel_context *ce,
1563 			    gfp_t gfp)
1564 {
1565 	struct intel_engine_capture_vma *vma = NULL;
1566 
1567 	ee->simulated |= record_context(&ee->context, ce);
1568 	if (ee->simulated)
1569 		return NULL;
1570 
1571 	/*
1572 	 * We need to copy these to an anonymous buffer
1573 	 * as the simplest method to avoid being overwritten
1574 	 * by userspace.
1575 	 */
1576 	vma = capture_vma(vma, ce->ring->vma, "ring", gfp);
1577 	vma = capture_vma(vma, ce->state, "HW context", gfp);
1578 
1579 	return vma;
1580 }
1581 
1582 struct intel_engine_capture_vma *
1583 intel_engine_coredump_add_request(struct intel_engine_coredump *ee,
1584 				  struct i915_request *rq,
1585 				  gfp_t gfp)
1586 {
1587 	struct intel_engine_capture_vma *vma;
1588 
1589 	vma = engine_coredump_add_context(ee, rq->context, gfp);
1590 	if (!vma)
1591 		return NULL;
1592 
1593 	/*
1594 	 * We need to copy these to an anonymous buffer
1595 	 * as the simplest method to avoid being overwritten
1596 	 * by userspace.
1597 	 */
1598 	vma = capture_vma_snapshot(vma, rq->batch_res, gfp, "batch");
1599 	vma = capture_user(vma, rq, gfp);
1600 
1601 	ee->rq_head = rq->head;
1602 	ee->rq_post = rq->postfix;
1603 	ee->rq_tail = rq->tail;
1604 
1605 	return vma;
1606 }
1607 
1608 void
1609 intel_engine_coredump_add_vma(struct intel_engine_coredump *ee,
1610 			      struct intel_engine_capture_vma *capture,
1611 			      struct i915_vma_compress *compress)
1612 {
1613 	const struct intel_engine_cs *engine = ee->engine;
1614 
1615 	while (capture) {
1616 		struct intel_engine_capture_vma *this = capture;
1617 		struct i915_vma_resource *vma_res = this->vma_res;
1618 
1619 		add_vma(ee,
1620 			i915_vma_coredump_create(engine->gt, vma_res,
1621 						 compress, this->name));
1622 
1623 		i915_vma_resource_unhold(vma_res, this->lockdep_cookie);
1624 		i915_vma_resource_put(vma_res);
1625 
1626 		capture = this->next;
1627 		kfree(this);
1628 	}
1629 
1630 	add_vma_coredump(ee, engine->gt, engine->status_page.vma,
1631 			 "HW Status", compress);
1632 
1633 	add_vma_coredump(ee, engine->gt, engine->wa_ctx.vma,
1634 			 "WA context", compress);
1635 }
1636 
1637 static struct intel_engine_coredump *
1638 capture_engine(struct intel_engine_cs *engine,
1639 	       struct i915_vma_compress *compress,
1640 	       u32 dump_flags)
1641 {
1642 	struct intel_engine_capture_vma *capture = NULL;
1643 	struct intel_engine_coredump *ee;
1644 	struct intel_context *ce = NULL;
1645 	struct i915_request *rq = NULL;
1646 
1647 	ee = intel_engine_coredump_alloc(engine, ALLOW_FAIL, dump_flags);
1648 	if (!ee)
1649 		return NULL;
1650 
1651 	intel_engine_get_hung_entity(engine, &ce, &rq);
1652 	if (rq && !i915_request_started(rq))
1653 		drm_info(&engine->gt->i915->drm, "Got hung context on %s with active request %lld:%lld [0x%04X] not yet started\n",
1654 			 engine->name, rq->fence.context, rq->fence.seqno, ce->guc_id.id);
1655 
1656 	if (rq) {
1657 		capture = intel_engine_coredump_add_request(ee, rq, ATOMIC_MAYFAIL);
1658 		i915_request_put(rq);
1659 	} else if (ce) {
1660 		capture = engine_coredump_add_context(ee, ce, ATOMIC_MAYFAIL);
1661 	}
1662 
1663 	if (capture) {
1664 		intel_engine_coredump_add_vma(ee, capture, compress);
1665 
1666 		if (dump_flags & CORE_DUMP_FLAG_IS_GUC_CAPTURE)
1667 			intel_guc_capture_get_matching_node(engine->gt, ee, ce);
1668 	} else {
1669 		kfree(ee);
1670 		ee = NULL;
1671 	}
1672 
1673 	return ee;
1674 }
1675 
1676 static void
1677 gt_record_engines(struct intel_gt_coredump *gt,
1678 		  intel_engine_mask_t engine_mask,
1679 		  struct i915_vma_compress *compress,
1680 		  u32 dump_flags)
1681 {
1682 	struct intel_engine_cs *engine;
1683 	enum intel_engine_id id;
1684 
1685 	for_each_engine(engine, gt->_gt, id) {
1686 		struct intel_engine_coredump *ee;
1687 
1688 		/* Refill our page pool before entering atomic section */
1689 		pool_refill(&compress->pool, ALLOW_FAIL);
1690 
1691 		ee = capture_engine(engine, compress, dump_flags);
1692 		if (!ee)
1693 			continue;
1694 
1695 		ee->hung = engine->mask & engine_mask;
1696 
1697 		gt->simulated |= ee->simulated;
1698 		if (ee->simulated) {
1699 			if (dump_flags & CORE_DUMP_FLAG_IS_GUC_CAPTURE)
1700 				intel_guc_capture_free_node(ee);
1701 			kfree(ee);
1702 			continue;
1703 		}
1704 
1705 		ee->next = gt->engine;
1706 		gt->engine = ee;
1707 	}
1708 }
1709 
1710 static void gt_record_guc_ctb(struct intel_ctb_coredump *saved,
1711 			      const struct intel_guc_ct_buffer *ctb,
1712 			      const void *blob_ptr, struct intel_guc *guc)
1713 {
1714 	if (!ctb || !ctb->desc)
1715 		return;
1716 
1717 	saved->raw_status = ctb->desc->status;
1718 	saved->raw_head = ctb->desc->head;
1719 	saved->raw_tail = ctb->desc->tail;
1720 	saved->head = ctb->head;
1721 	saved->tail = ctb->tail;
1722 	saved->size = ctb->size;
1723 	saved->desc_offset = ((void *)ctb->desc) - blob_ptr;
1724 	saved->cmds_offset = ((void *)ctb->cmds) - blob_ptr;
1725 }
1726 
1727 static struct intel_uc_coredump *
1728 gt_record_uc(struct intel_gt_coredump *gt,
1729 	     struct i915_vma_compress *compress)
1730 {
1731 	const struct intel_uc *uc = &gt->_gt->uc;
1732 	struct intel_uc_coredump *error_uc;
1733 
1734 	error_uc = kzalloc(sizeof(*error_uc), ALLOW_FAIL);
1735 	if (!error_uc)
1736 		return NULL;
1737 
1738 	memcpy(&error_uc->guc_fw, &uc->guc.fw, sizeof(uc->guc.fw));
1739 	memcpy(&error_uc->huc_fw, &uc->huc.fw, sizeof(uc->huc.fw));
1740 
1741 	error_uc->guc_fw.file_selected.path = kstrdup(uc->guc.fw.file_selected.path, ALLOW_FAIL);
1742 	error_uc->huc_fw.file_selected.path = kstrdup(uc->huc.fw.file_selected.path, ALLOW_FAIL);
1743 	error_uc->guc_fw.file_wanted.path = kstrdup(uc->guc.fw.file_wanted.path, ALLOW_FAIL);
1744 	error_uc->huc_fw.file_wanted.path = kstrdup(uc->huc.fw.file_wanted.path, ALLOW_FAIL);
1745 
1746 	/*
1747 	 * Save the GuC log and include a timestamp reference for converting the
1748 	 * log times to system times (in conjunction with the error->boottime and
1749 	 * gt->clock_frequency fields saved elsewhere).
1750 	 */
1751 	error_uc->guc.timestamp = intel_uncore_read(gt->_gt->uncore, GUCPMTIMESTAMP);
1752 	error_uc->guc.vma_log = create_vma_coredump(gt->_gt, uc->guc.log.vma,
1753 						    "GuC log buffer", compress);
1754 	error_uc->guc.vma_ctb = create_vma_coredump(gt->_gt, uc->guc.ct.vma,
1755 						    "GuC CT buffer", compress);
1756 	error_uc->guc.last_fence = uc->guc.ct.requests.last_fence;
1757 	gt_record_guc_ctb(error_uc->guc.ctb + 0, &uc->guc.ct.ctbs.send,
1758 			  uc->guc.ct.ctbs.send.desc, (struct intel_guc *)&uc->guc);
1759 	gt_record_guc_ctb(error_uc->guc.ctb + 1, &uc->guc.ct.ctbs.recv,
1760 			  uc->guc.ct.ctbs.send.desc, (struct intel_guc *)&uc->guc);
1761 
1762 	return error_uc;
1763 }
1764 
1765 /* Capture display registers. */
1766 static void gt_record_display_regs(struct intel_gt_coredump *gt)
1767 {
1768 	struct intel_uncore *uncore = gt->_gt->uncore;
1769 	struct drm_i915_private *i915 = uncore->i915;
1770 
1771 	if (DISPLAY_VER(i915) >= 6 && DISPLAY_VER(i915) < 20)
1772 		gt->derrmr = intel_uncore_read(uncore, DERRMR);
1773 
1774 	if (GRAPHICS_VER(i915) >= 8)
1775 		gt->ier = intel_uncore_read(uncore, GEN8_DE_MISC_IER);
1776 	else if (IS_VALLEYVIEW(i915))
1777 		gt->ier = intel_uncore_read(uncore, VLV_IER);
1778 	else if (HAS_PCH_SPLIT(i915))
1779 		gt->ier = intel_uncore_read(uncore, DEIER);
1780 	else if (GRAPHICS_VER(i915) == 2)
1781 		gt->ier = intel_uncore_read16(uncore, GEN2_IER);
1782 	else
1783 		gt->ier = intel_uncore_read(uncore, GEN2_IER);
1784 }
1785 
1786 /* Capture all other registers that GuC doesn't capture. */
1787 static void gt_record_global_nonguc_regs(struct intel_gt_coredump *gt)
1788 {
1789 	struct intel_uncore *uncore = gt->_gt->uncore;
1790 	struct drm_i915_private *i915 = uncore->i915;
1791 	int i;
1792 
1793 	if (IS_VALLEYVIEW(i915)) {
1794 		gt->gtier[0] = intel_uncore_read(uncore, GTIER);
1795 		gt->ngtier = 1;
1796 	} else if (GRAPHICS_VER(i915) >= 11) {
1797 		gt->gtier[0] =
1798 			intel_uncore_read(uncore,
1799 					  GEN11_RENDER_COPY_INTR_ENABLE);
1800 		gt->gtier[1] =
1801 			intel_uncore_read(uncore, GEN11_VCS_VECS_INTR_ENABLE);
1802 		gt->gtier[2] =
1803 			intel_uncore_read(uncore, GEN11_GUC_SG_INTR_ENABLE);
1804 		gt->gtier[3] =
1805 			intel_uncore_read(uncore,
1806 					  GEN11_GPM_WGBOXPERF_INTR_ENABLE);
1807 		gt->gtier[4] =
1808 			intel_uncore_read(uncore,
1809 					  GEN11_CRYPTO_RSVD_INTR_ENABLE);
1810 		gt->gtier[5] =
1811 			intel_uncore_read(uncore,
1812 					  GEN11_GUNIT_CSME_INTR_ENABLE);
1813 		gt->ngtier = 6;
1814 	} else if (GRAPHICS_VER(i915) >= 8) {
1815 		for (i = 0; i < 4; i++)
1816 			gt->gtier[i] =
1817 				intel_uncore_read(uncore, GEN8_GT_IER(i));
1818 		gt->ngtier = 4;
1819 	} else if (HAS_PCH_SPLIT(i915)) {
1820 		gt->gtier[0] = intel_uncore_read(uncore, GTIER);
1821 		gt->ngtier = 1;
1822 	}
1823 
1824 	gt->eir = intel_uncore_read(uncore, EIR);
1825 	gt->pgtbl_er = intel_uncore_read(uncore, PGTBL_ER);
1826 }
1827 
1828 /*
1829  * Capture all registers that relate to workload submission.
1830  * NOTE: In GuC submission, when GuC resets an engine, it can dump these for us
1831  */
1832 static void gt_record_global_regs(struct intel_gt_coredump *gt)
1833 {
1834 	struct intel_uncore *uncore = gt->_gt->uncore;
1835 	struct drm_i915_private *i915 = uncore->i915;
1836 	int i;
1837 
1838 	/*
1839 	 * General organization
1840 	 * 1. Registers specific to a single generation
1841 	 * 2. Registers which belong to multiple generations
1842 	 * 3. Feature specific registers.
1843 	 * 4. Everything else
1844 	 * Please try to follow the order.
1845 	 */
1846 
1847 	/* 1: Registers specific to a single generation */
1848 	if (IS_VALLEYVIEW(i915))
1849 		gt->forcewake = intel_uncore_read_fw(uncore, FORCEWAKE_VLV);
1850 
1851 	if (GRAPHICS_VER(i915) == 7)
1852 		gt->err_int = intel_uncore_read(uncore, GEN7_ERR_INT);
1853 
1854 	if (GRAPHICS_VER_FULL(i915) >= IP_VER(12, 55)) {
1855 		gt->fault_data0 = intel_gt_mcr_read_any((struct intel_gt *)gt->_gt,
1856 							XEHP_FAULT_TLB_DATA0);
1857 		gt->fault_data1 = intel_gt_mcr_read_any((struct intel_gt *)gt->_gt,
1858 							XEHP_FAULT_TLB_DATA1);
1859 	} else if (GRAPHICS_VER(i915) >= 12) {
1860 		gt->fault_data0 = intel_uncore_read(uncore,
1861 						    GEN12_FAULT_TLB_DATA0);
1862 		gt->fault_data1 = intel_uncore_read(uncore,
1863 						    GEN12_FAULT_TLB_DATA1);
1864 	} else if (GRAPHICS_VER(i915) >= 8) {
1865 		gt->fault_data0 = intel_uncore_read(uncore,
1866 						    GEN8_FAULT_TLB_DATA0);
1867 		gt->fault_data1 = intel_uncore_read(uncore,
1868 						    GEN8_FAULT_TLB_DATA1);
1869 	}
1870 
1871 	if (GRAPHICS_VER(i915) == 6) {
1872 		gt->forcewake = intel_uncore_read_fw(uncore, FORCEWAKE);
1873 		gt->gab_ctl = intel_uncore_read(uncore, GAB_CTL);
1874 		gt->gfx_mode = intel_uncore_read(uncore, GFX_MODE);
1875 	}
1876 
1877 	/* 2: Registers which belong to multiple generations */
1878 	if (GRAPHICS_VER(i915) >= 7)
1879 		gt->forcewake = intel_uncore_read_fw(uncore, FORCEWAKE_MT);
1880 
1881 	if (GRAPHICS_VER(i915) >= 6) {
1882 		if (GRAPHICS_VER(i915) < 12) {
1883 			gt->error = intel_uncore_read(uncore, ERROR_GEN6);
1884 			gt->done_reg = intel_uncore_read(uncore, DONE_REG);
1885 		}
1886 	}
1887 
1888 	/* 3: Feature specific registers */
1889 	if (IS_GRAPHICS_VER(i915, 6, 7)) {
1890 		gt->gam_ecochk = intel_uncore_read(uncore, GAM_ECOCHK);
1891 		gt->gac_eco = intel_uncore_read(uncore, GAC_ECO_BITS);
1892 	}
1893 
1894 	if (IS_GRAPHICS_VER(i915, 8, 11))
1895 		gt->gtt_cache = intel_uncore_read(uncore, HSW_GTT_CACHE_EN);
1896 
1897 	if (GRAPHICS_VER(i915) == 12)
1898 		gt->aux_err = intel_uncore_read(uncore, GEN12_AUX_ERR_DBG);
1899 
1900 	if (GRAPHICS_VER(i915) >= 12) {
1901 		for (i = 0; i < I915_MAX_SFC; i++) {
1902 			/*
1903 			 * SFC_DONE resides in the VD forcewake domain, so it
1904 			 * only exists if the corresponding VCS engine is
1905 			 * present.
1906 			 */
1907 			if ((gt->_gt->info.sfc_mask & BIT(i)) == 0 ||
1908 			    !HAS_ENGINE(gt->_gt, _VCS(i * 2)))
1909 				continue;
1910 
1911 			gt->sfc_done[i] =
1912 				intel_uncore_read(uncore, GEN12_SFC_DONE(i));
1913 		}
1914 
1915 		gt->gam_done = intel_uncore_read(uncore, GEN12_GAM_DONE);
1916 	}
1917 }
1918 
1919 static void gt_record_info(struct intel_gt_coredump *gt)
1920 {
1921 	memcpy(&gt->info, &gt->_gt->info, sizeof(struct intel_gt_info));
1922 	gt->clock_frequency = gt->_gt->clock_frequency;
1923 	gt->clock_period_ns = gt->_gt->clock_period_ns;
1924 }
1925 
1926 /*
1927  * Generate a semi-unique error code. The code is not meant to have meaning, The
1928  * code's only purpose is to try to prevent false duplicated bug reports by
1929  * grossly estimating a GPU error state.
1930  *
1931  * TODO Ideally, hashing the batchbuffer would be a very nice way to determine
1932  * the hang if we could strip the GTT offset information from it.
1933  *
1934  * It's only a small step better than a random number in its current form.
1935  */
1936 static u32 generate_ecode(const struct intel_engine_coredump *ee)
1937 {
1938 	/*
1939 	 * IPEHR would be an ideal way to detect errors, as it's the gross
1940 	 * measure of "the command that hung." However, has some very common
1941 	 * synchronization commands which almost always appear in the case
1942 	 * strictly a client bug. Use instdone to differentiate those some.
1943 	 */
1944 	return ee ? ee->ipehr ^ ee->instdone.instdone : 0;
1945 }
1946 
1947 static const char *error_msg(struct i915_gpu_coredump *error)
1948 {
1949 	struct intel_engine_coredump *first = NULL;
1950 	unsigned int hung_classes = 0;
1951 	struct intel_gt_coredump *gt;
1952 	int len;
1953 
1954 	for (gt = error->gt; gt; gt = gt->next) {
1955 		struct intel_engine_coredump *cs;
1956 
1957 		for (cs = gt->engine; cs; cs = cs->next) {
1958 			if (cs->hung) {
1959 				hung_classes |= BIT(cs->engine->uabi_class);
1960 				if (!first)
1961 					first = cs;
1962 			}
1963 		}
1964 	}
1965 
1966 	len = scnprintf(error->error_msg, sizeof(error->error_msg),
1967 			"GPU HANG: ecode %d:%x:%08x",
1968 			GRAPHICS_VER(error->i915), hung_classes,
1969 			generate_ecode(first));
1970 	if (first && first->context.pid) {
1971 		/* Just show the first executing process, more is confusing */
1972 		len += scnprintf(error->error_msg + len,
1973 				 sizeof(error->error_msg) - len,
1974 				 ", in %s [%d]",
1975 				 first->context.comm, first->context.pid);
1976 	}
1977 
1978 	return error->error_msg;
1979 }
1980 
1981 static void capture_gen(struct i915_gpu_coredump *error)
1982 {
1983 	struct drm_i915_private *i915 = error->i915;
1984 
1985 	error->wakelock = atomic_read(&i915->runtime_pm.wakeref_count);
1986 	error->suspended = pm_runtime_suspended(i915->drm.dev);
1987 
1988 	error->iommu = i915_vtd_active(i915);
1989 	error->reset_count = i915_reset_count(&i915->gpu_error);
1990 	error->suspend_count = i915->suspend_count;
1991 
1992 	i915_params_copy(&error->params, &i915->params);
1993 	intel_display_params_copy(&error->display_params);
1994 	memcpy(&error->device_info,
1995 	       INTEL_INFO(i915),
1996 	       sizeof(error->device_info));
1997 	memcpy(&error->runtime_info,
1998 	       RUNTIME_INFO(i915),
1999 	       sizeof(error->runtime_info));
2000 	memcpy(&error->display_device_info, DISPLAY_INFO(i915),
2001 	       sizeof(error->display_device_info));
2002 	memcpy(&error->display_runtime_info, DISPLAY_RUNTIME_INFO(i915),
2003 	       sizeof(error->display_runtime_info));
2004 	error->driver_caps = i915->caps;
2005 }
2006 
2007 struct i915_gpu_coredump *
2008 i915_gpu_coredump_alloc(struct drm_i915_private *i915, gfp_t gfp)
2009 {
2010 	struct i915_gpu_coredump *error;
2011 
2012 	if (!i915->params.error_capture)
2013 		return NULL;
2014 
2015 	error = kzalloc(sizeof(*error), gfp);
2016 	if (!error)
2017 		return NULL;
2018 
2019 	kref_init(&error->ref);
2020 	error->i915 = i915;
2021 
2022 	error->time = ktime_get_real();
2023 	error->boottime = ktime_get_boottime();
2024 	error->uptime = ktime_sub(ktime_get(), to_gt(i915)->last_init_time);
2025 	error->capture = jiffies;
2026 
2027 	capture_gen(error);
2028 
2029 	return error;
2030 }
2031 
2032 #define DAY_AS_SECONDS(x) (24 * 60 * 60 * (x))
2033 
2034 struct intel_gt_coredump *
2035 intel_gt_coredump_alloc(struct intel_gt *gt, gfp_t gfp, u32 dump_flags)
2036 {
2037 	struct intel_gt_coredump *gc;
2038 
2039 	gc = kzalloc(sizeof(*gc), gfp);
2040 	if (!gc)
2041 		return NULL;
2042 
2043 	gc->_gt = gt;
2044 	gc->awake = intel_gt_pm_is_awake(gt);
2045 
2046 	gt_record_display_regs(gc);
2047 	gt_record_global_nonguc_regs(gc);
2048 
2049 	/*
2050 	 * GuC dumps global, eng-class and eng-instance registers
2051 	 * (that can change as part of engine state during execution)
2052 	 * before an engine is reset due to a hung context.
2053 	 * GuC captures and reports all three groups of registers
2054 	 * together as a single set before the engine is reset.
2055 	 * Thus, if GuC triggered the context reset we retrieve
2056 	 * the register values as part of gt_record_engines.
2057 	 */
2058 	if (!(dump_flags & CORE_DUMP_FLAG_IS_GUC_CAPTURE))
2059 		gt_record_global_regs(gc);
2060 
2061 	gt_record_fences(gc);
2062 
2063 	return gc;
2064 }
2065 
2066 struct i915_vma_compress *
2067 i915_vma_capture_prepare(struct intel_gt_coredump *gt)
2068 {
2069 	struct i915_vma_compress *compress;
2070 
2071 	compress = kmalloc(sizeof(*compress), ALLOW_FAIL);
2072 	if (!compress)
2073 		return NULL;
2074 
2075 	if (!compress_init(compress)) {
2076 		kfree(compress);
2077 		return NULL;
2078 	}
2079 
2080 	return compress;
2081 }
2082 
2083 void i915_vma_capture_finish(struct intel_gt_coredump *gt,
2084 			     struct i915_vma_compress *compress)
2085 {
2086 	if (!compress)
2087 		return;
2088 
2089 	compress_fini(compress);
2090 	kfree(compress);
2091 }
2092 
2093 static struct i915_gpu_coredump *
2094 __i915_gpu_coredump(struct intel_gt *gt, intel_engine_mask_t engine_mask, u32 dump_flags)
2095 {
2096 	struct drm_i915_private *i915 = gt->i915;
2097 	struct i915_gpu_coredump *error;
2098 
2099 	/* Check if GPU capture has been disabled */
2100 	error = READ_ONCE(i915->gpu_error.first_error);
2101 	if (IS_ERR(error))
2102 		return error;
2103 
2104 	error = i915_gpu_coredump_alloc(i915, ALLOW_FAIL);
2105 	if (!error)
2106 		return ERR_PTR(-ENOMEM);
2107 
2108 	error->gt = intel_gt_coredump_alloc(gt, ALLOW_FAIL, dump_flags);
2109 	if (error->gt) {
2110 		struct i915_vma_compress *compress;
2111 
2112 		compress = i915_vma_capture_prepare(error->gt);
2113 		if (!compress) {
2114 			kfree(error->gt);
2115 			kfree(error);
2116 			return ERR_PTR(-ENOMEM);
2117 		}
2118 
2119 		if (INTEL_INFO(i915)->has_gt_uc) {
2120 			error->gt->uc = gt_record_uc(error->gt, compress);
2121 			if (error->gt->uc) {
2122 				if (dump_flags & CORE_DUMP_FLAG_IS_GUC_CAPTURE)
2123 					error->gt->uc->guc.is_guc_capture = true;
2124 				else
2125 					GEM_BUG_ON(error->gt->uc->guc.is_guc_capture);
2126 			}
2127 		}
2128 
2129 		gt_record_info(error->gt);
2130 		gt_record_engines(error->gt, engine_mask, compress, dump_flags);
2131 
2132 
2133 		i915_vma_capture_finish(error->gt, compress);
2134 
2135 		error->simulated |= error->gt->simulated;
2136 	}
2137 
2138 	error->overlay = intel_overlay_capture_error_state(i915);
2139 
2140 	return error;
2141 }
2142 
2143 static struct i915_gpu_coredump *
2144 i915_gpu_coredump(struct intel_gt *gt, intel_engine_mask_t engine_mask, u32 dump_flags)
2145 {
2146 	static DEFINE_MUTEX(capture_mutex);
2147 	int ret = mutex_lock_interruptible(&capture_mutex);
2148 	struct i915_gpu_coredump *dump;
2149 
2150 	if (ret)
2151 		return ERR_PTR(ret);
2152 
2153 	dump = __i915_gpu_coredump(gt, engine_mask, dump_flags);
2154 	mutex_unlock(&capture_mutex);
2155 
2156 	return dump;
2157 }
2158 
2159 void i915_error_state_store(struct i915_gpu_coredump *error)
2160 {
2161 	struct drm_i915_private *i915;
2162 	static bool warned;
2163 
2164 	if (IS_ERR_OR_NULL(error))
2165 		return;
2166 
2167 	i915 = error->i915;
2168 	drm_info(&i915->drm, "%s\n", error_msg(error));
2169 
2170 	if (error->simulated ||
2171 	    cmpxchg(&i915->gpu_error.first_error, NULL, error))
2172 		return;
2173 
2174 	i915_gpu_coredump_get(error);
2175 
2176 	if (!xchg(&warned, true) &&
2177 	    ktime_get_real_seconds() - DRIVER_TIMESTAMP < DAY_AS_SECONDS(180)) {
2178 		pr_info("GPU hangs can indicate a bug anywhere in the entire gfx stack, including userspace.\n");
2179 		pr_info("Please file a _new_ bug report at https://gitlab.freedesktop.org/drm/intel/issues/new.\n");
2180 		pr_info("Please see https://drm.pages.freedesktop.org/intel-docs/how-to-file-i915-bugs.html for details.\n");
2181 		pr_info("drm/i915 developers can then reassign to the right component if it's not a kernel issue.\n");
2182 		pr_info("The GPU crash dump is required to analyze GPU hangs, so please always attach it.\n");
2183 		pr_info("GPU crash dump saved to /sys/class/drm/card%d/error\n",
2184 			i915->drm.primary->index);
2185 	}
2186 }
2187 
2188 /**
2189  * i915_capture_error_state - capture an error record for later analysis
2190  * @gt: intel_gt which originated the hang
2191  * @engine_mask: hung engines
2192  * @dump_flags: dump flags
2193  *
2194  * Should be called when an error is detected (either a hang or an error
2195  * interrupt) to capture error state from the time of the error.  Fills
2196  * out a structure which becomes available in debugfs for user level tools
2197  * to pick up.
2198  */
2199 void i915_capture_error_state(struct intel_gt *gt,
2200 			      intel_engine_mask_t engine_mask, u32 dump_flags)
2201 {
2202 	struct i915_gpu_coredump *error;
2203 
2204 	error = i915_gpu_coredump(gt, engine_mask, dump_flags);
2205 	if (IS_ERR(error)) {
2206 		cmpxchg(&gt->i915->gpu_error.first_error, NULL, error);
2207 		return;
2208 	}
2209 
2210 	i915_error_state_store(error);
2211 	i915_gpu_coredump_put(error);
2212 }
2213 
2214 static struct i915_gpu_coredump *
2215 i915_first_error_state(struct drm_i915_private *i915)
2216 {
2217 	struct i915_gpu_coredump *error;
2218 
2219 	spin_lock_irq(&i915->gpu_error.lock);
2220 	error = i915->gpu_error.first_error;
2221 	if (!IS_ERR_OR_NULL(error))
2222 		i915_gpu_coredump_get(error);
2223 	spin_unlock_irq(&i915->gpu_error.lock);
2224 
2225 	return error;
2226 }
2227 
2228 void i915_reset_error_state(struct drm_i915_private *i915)
2229 {
2230 	struct i915_gpu_coredump *error;
2231 
2232 	spin_lock_irq(&i915->gpu_error.lock);
2233 	error = i915->gpu_error.first_error;
2234 	if (error != ERR_PTR(-ENODEV)) /* if disabled, always disabled */
2235 		i915->gpu_error.first_error = NULL;
2236 	spin_unlock_irq(&i915->gpu_error.lock);
2237 
2238 	if (!IS_ERR_OR_NULL(error))
2239 		i915_gpu_coredump_put(error);
2240 }
2241 
2242 void i915_disable_error_state(struct drm_i915_private *i915, int err)
2243 {
2244 	spin_lock_irq(&i915->gpu_error.lock);
2245 	if (!i915->gpu_error.first_error)
2246 		i915->gpu_error.first_error = ERR_PTR(err);
2247 	spin_unlock_irq(&i915->gpu_error.lock);
2248 }
2249 
2250 #if IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM)
2251 void intel_klog_error_capture(struct intel_gt *gt,
2252 			      intel_engine_mask_t engine_mask)
2253 {
2254 	static int g_count;
2255 	struct drm_i915_private *i915 = gt->i915;
2256 	struct i915_gpu_coredump *error;
2257 	intel_wakeref_t wakeref;
2258 	size_t buf_size = PAGE_SIZE * 128;
2259 	size_t pos_err;
2260 	char *buf, *ptr, *next;
2261 	int l_count = g_count++;
2262 	int line = 0;
2263 
2264 	/* Can't allocate memory during a reset */
2265 	if (test_bit(I915_RESET_BACKOFF, &gt->reset.flags)) {
2266 		drm_err(&gt->i915->drm, "[Capture/%d.%d] Inside GT reset, skipping error capture :(\n",
2267 			l_count, line++);
2268 		return;
2269 	}
2270 
2271 	error = READ_ONCE(i915->gpu_error.first_error);
2272 	if (error) {
2273 		drm_err(&i915->drm, "[Capture/%d.%d] Clearing existing error capture first...\n",
2274 			l_count, line++);
2275 		i915_reset_error_state(i915);
2276 	}
2277 
2278 	with_intel_runtime_pm(&i915->runtime_pm, wakeref)
2279 		error = i915_gpu_coredump(gt, engine_mask, CORE_DUMP_FLAG_NONE);
2280 
2281 	if (IS_ERR(error)) {
2282 		drm_err(&i915->drm, "[Capture/%d.%d] Failed to capture error capture: %ld!\n",
2283 			l_count, line++, PTR_ERR(error));
2284 		return;
2285 	}
2286 
2287 	buf = kvmalloc(buf_size, GFP_KERNEL);
2288 	if (!buf) {
2289 		drm_err(&i915->drm, "[Capture/%d.%d] Failed to allocate buffer for error capture!\n",
2290 			l_count, line++);
2291 		i915_gpu_coredump_put(error);
2292 		return;
2293 	}
2294 
2295 	drm_info(&i915->drm, "[Capture/%d.%d] Dumping i915 error capture for %ps...\n",
2296 		 l_count, line++, __builtin_return_address(0));
2297 
2298 	/* Largest string length safe to print via dmesg */
2299 #	define MAX_CHUNK	800
2300 
2301 	pos_err = 0;
2302 	while (1) {
2303 		ssize_t got = i915_gpu_coredump_copy_to_buffer(error, buf, pos_err, buf_size - 1);
2304 
2305 		if (got <= 0)
2306 			break;
2307 
2308 		buf[got] = 0;
2309 		pos_err += got;
2310 
2311 		ptr = buf;
2312 		while (got > 0) {
2313 			size_t count;
2314 			char tag[2];
2315 
2316 			next = strnchr(ptr, got, '\n');
2317 			if (next) {
2318 				count = next - ptr;
2319 				*next = 0;
2320 				tag[0] = '>';
2321 				tag[1] = '<';
2322 			} else {
2323 				count = got;
2324 				tag[0] = '}';
2325 				tag[1] = '{';
2326 			}
2327 
2328 			if (count > MAX_CHUNK) {
2329 				size_t pos;
2330 				char *ptr2 = ptr;
2331 
2332 				for (pos = MAX_CHUNK; pos < count; pos += MAX_CHUNK) {
2333 					char chr = ptr[pos];
2334 
2335 					ptr[pos] = 0;
2336 					drm_info(&i915->drm, "[Capture/%d.%d] }%s{\n",
2337 						 l_count, line++, ptr2);
2338 					ptr[pos] = chr;
2339 					ptr2 = ptr + pos;
2340 
2341 					/*
2342 					 * If spewing large amounts of data via a serial console,
2343 					 * this can be a very slow process. So be friendly and try
2344 					 * not to cause 'softlockup on CPU' problems.
2345 					 */
2346 					cond_resched();
2347 				}
2348 
2349 				if (ptr2 < (ptr + count))
2350 					drm_info(&i915->drm, "[Capture/%d.%d] %c%s%c\n",
2351 						 l_count, line++, tag[0], ptr2, tag[1]);
2352 				else if (tag[0] == '>')
2353 					drm_info(&i915->drm, "[Capture/%d.%d] ><\n",
2354 						 l_count, line++);
2355 			} else {
2356 				drm_info(&i915->drm, "[Capture/%d.%d] %c%s%c\n",
2357 					 l_count, line++, tag[0], ptr, tag[1]);
2358 			}
2359 
2360 			ptr = next;
2361 			got -= count;
2362 			if (next) {
2363 				ptr++;
2364 				got--;
2365 			}
2366 
2367 			/* As above. */
2368 			cond_resched();
2369 		}
2370 
2371 		if (got)
2372 			drm_info(&i915->drm, "[Capture/%d.%d] Got %zd bytes remaining!\n",
2373 				 l_count, line++, got);
2374 	}
2375 
2376 	kvfree(buf);
2377 
2378 	drm_info(&i915->drm, "[Capture/%d.%d] Dumped %zd bytes\n", l_count, line++, pos_err);
2379 }
2380 #endif
2381 
2382 static ssize_t gpu_state_read(struct file *file, char __user *ubuf,
2383 			      size_t count, loff_t *pos)
2384 {
2385 	struct i915_gpu_coredump *error;
2386 	ssize_t ret;
2387 	void *buf;
2388 
2389 	error = file->private_data;
2390 	if (!error)
2391 		return 0;
2392 
2393 	/* Bounce buffer required because of kernfs __user API convenience. */
2394 	buf = kmalloc(count, GFP_KERNEL);
2395 	if (!buf)
2396 		return -ENOMEM;
2397 
2398 	ret = i915_gpu_coredump_copy_to_buffer(error, buf, *pos, count);
2399 	if (ret <= 0)
2400 		goto out;
2401 
2402 	if (!copy_to_user(ubuf, buf, ret))
2403 		*pos += ret;
2404 	else
2405 		ret = -EFAULT;
2406 
2407 out:
2408 	kfree(buf);
2409 	return ret;
2410 }
2411 
2412 static int gpu_state_release(struct inode *inode, struct file *file)
2413 {
2414 	i915_gpu_coredump_put(file->private_data);
2415 	return 0;
2416 }
2417 
2418 static int i915_gpu_info_open(struct inode *inode, struct file *file)
2419 {
2420 	struct drm_i915_private *i915 = inode->i_private;
2421 	struct i915_gpu_coredump *gpu;
2422 	intel_wakeref_t wakeref;
2423 
2424 	gpu = NULL;
2425 	with_intel_runtime_pm(&i915->runtime_pm, wakeref)
2426 		gpu = i915_gpu_coredump(to_gt(i915), ALL_ENGINES, CORE_DUMP_FLAG_NONE);
2427 
2428 	if (IS_ERR(gpu))
2429 		return PTR_ERR(gpu);
2430 
2431 	file->private_data = gpu;
2432 	return 0;
2433 }
2434 
2435 static const struct file_operations i915_gpu_info_fops = {
2436 	.owner = THIS_MODULE,
2437 	.open = i915_gpu_info_open,
2438 	.read = gpu_state_read,
2439 	.llseek = default_llseek,
2440 	.release = gpu_state_release,
2441 };
2442 
2443 static ssize_t
2444 i915_error_state_write(struct file *filp,
2445 		       const char __user *ubuf,
2446 		       size_t cnt,
2447 		       loff_t *ppos)
2448 {
2449 	struct i915_gpu_coredump *error = filp->private_data;
2450 
2451 	if (!error)
2452 		return 0;
2453 
2454 	drm_dbg(&error->i915->drm, "Resetting error state\n");
2455 	i915_reset_error_state(error->i915);
2456 
2457 	return cnt;
2458 }
2459 
2460 static int i915_error_state_open(struct inode *inode, struct file *file)
2461 {
2462 	struct i915_gpu_coredump *error;
2463 
2464 	error = i915_first_error_state(inode->i_private);
2465 	if (IS_ERR(error))
2466 		return PTR_ERR(error);
2467 
2468 	file->private_data  = error;
2469 	return 0;
2470 }
2471 
2472 static const struct file_operations i915_error_state_fops = {
2473 	.owner = THIS_MODULE,
2474 	.open = i915_error_state_open,
2475 	.read = gpu_state_read,
2476 	.write = i915_error_state_write,
2477 	.llseek = default_llseek,
2478 	.release = gpu_state_release,
2479 };
2480 
2481 void i915_gpu_error_debugfs_register(struct drm_i915_private *i915)
2482 {
2483 	struct drm_minor *minor = i915->drm.primary;
2484 
2485 	debugfs_create_file("i915_error_state", 0644, minor->debugfs_root, i915,
2486 			    &i915_error_state_fops);
2487 	debugfs_create_file("i915_gpu_info", 0644, minor->debugfs_root, i915,
2488 			    &i915_gpu_info_fops);
2489 }
2490 
2491 static ssize_t error_state_read(struct file *filp, struct kobject *kobj,
2492 				struct bin_attribute *attr, char *buf,
2493 				loff_t off, size_t count)
2494 {
2495 
2496 	struct device *kdev = kobj_to_dev(kobj);
2497 	struct drm_i915_private *i915 = kdev_minor_to_i915(kdev);
2498 	struct i915_gpu_coredump *gpu;
2499 	ssize_t ret = 0;
2500 
2501 	/*
2502 	 * FIXME: Concurrent clients triggering resets and reading + clearing
2503 	 * dumps can cause inconsistent sysfs reads when a user calls in with a
2504 	 * non-zero offset to complete a prior partial read but the
2505 	 * gpu_coredump has been cleared or replaced.
2506 	 */
2507 
2508 	gpu = i915_first_error_state(i915);
2509 	if (IS_ERR(gpu)) {
2510 		ret = PTR_ERR(gpu);
2511 	} else if (gpu) {
2512 		ret = i915_gpu_coredump_copy_to_buffer(gpu, buf, off, count);
2513 		i915_gpu_coredump_put(gpu);
2514 	} else {
2515 		const char *str = "No error state collected\n";
2516 		size_t len = strlen(str);
2517 
2518 		if (off < len) {
2519 			ret = min_t(size_t, count, len - off);
2520 			memcpy(buf, str + off, ret);
2521 		}
2522 	}
2523 
2524 	return ret;
2525 }
2526 
2527 static ssize_t error_state_write(struct file *file, struct kobject *kobj,
2528 				 struct bin_attribute *attr, char *buf,
2529 				 loff_t off, size_t count)
2530 {
2531 	struct device *kdev = kobj_to_dev(kobj);
2532 	struct drm_i915_private *dev_priv = kdev_minor_to_i915(kdev);
2533 
2534 	drm_dbg(&dev_priv->drm, "Resetting error state\n");
2535 	i915_reset_error_state(dev_priv);
2536 
2537 	return count;
2538 }
2539 
2540 static const struct bin_attribute error_state_attr = {
2541 	.attr.name = "error",
2542 	.attr.mode = S_IRUSR | S_IWUSR,
2543 	.size = 0,
2544 	.read = error_state_read,
2545 	.write = error_state_write,
2546 };
2547 
2548 void i915_gpu_error_sysfs_setup(struct drm_i915_private *i915)
2549 {
2550 	struct device *kdev = i915->drm.primary->kdev;
2551 
2552 	if (sysfs_create_bin_file(&kdev->kobj, &error_state_attr))
2553 		drm_err(&i915->drm, "error_state sysfs setup failed\n");
2554 }
2555 
2556 void i915_gpu_error_sysfs_teardown(struct drm_i915_private *i915)
2557 {
2558 	struct device *kdev = i915->drm.primary->kdev;
2559 
2560 	sysfs_remove_bin_file(&kdev->kobj, &error_state_attr);
2561 }
2562