xref: /linux/drivers/gpu/drm/i915/i915_gpu_error.c (revision 7f71507851fc7764b36a3221839607d3a45c2025)
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/debugfs.h>
32 #include <linux/highmem.h>
33 #include <linux/nmi.h>
34 #include <linux/pagevec.h>
35 #include <linux/scatterlist.h>
36 #include <linux/string_helpers.h>
37 #include <linux/utsname.h>
38 #include <linux/zlib.h>
39 
40 #include <drm/drm_cache.h>
41 #include <drm/drm_print.h>
42 
43 #include "display/intel_display_snapshot.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_driver_caps_print(&error->driver_caps, &p);
654 }
655 
656 static void err_print_params(struct drm_i915_error_state_buf *m,
657 			     const struct i915_params *params)
658 {
659 	struct drm_printer p = i915_error_printer(m);
660 
661 	i915_params_dump(params, &p);
662 }
663 
664 static void err_print_pciid(struct drm_i915_error_state_buf *m,
665 			    struct drm_i915_private *i915)
666 {
667 	struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
668 
669 	err_printf(m, "PCI ID: 0x%04x\n", pdev->device);
670 	err_printf(m, "PCI Revision: 0x%02x\n", pdev->revision);
671 	err_printf(m, "PCI Subsystem: %04x:%04x\n",
672 		   pdev->subsystem_vendor,
673 		   pdev->subsystem_device);
674 }
675 
676 static void err_print_guc_ctb(struct drm_i915_error_state_buf *m,
677 			      const char *name,
678 			      const struct intel_ctb_coredump *ctb)
679 {
680 	if (!ctb->size)
681 		return;
682 
683 	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",
684 		   name, ctb->raw_status, ctb->raw_head, ctb->raw_tail,
685 		   ctb->head, ctb->tail, ctb->desc_offset, ctb->cmds_offset, ctb->size);
686 }
687 
688 static void err_print_uc(struct drm_i915_error_state_buf *m,
689 			 const struct intel_uc_coredump *error_uc)
690 {
691 	struct drm_printer p = i915_error_printer(m);
692 
693 	intel_uc_fw_dump(&error_uc->guc_fw, &p);
694 	intel_uc_fw_dump(&error_uc->huc_fw, &p);
695 	err_printf(m, "GuC timestamp: 0x%08x\n", error_uc->guc.timestamp);
696 	intel_gpu_error_print_vma(m, NULL, error_uc->guc.vma_log);
697 	err_printf(m, "GuC CTB fence: %d\n", error_uc->guc.last_fence);
698 	err_print_guc_ctb(m, "Send", error_uc->guc.ctb + 0);
699 	err_print_guc_ctb(m, "Recv", error_uc->guc.ctb + 1);
700 	intel_gpu_error_print_vma(m, NULL, error_uc->guc.vma_ctb);
701 }
702 
703 static void err_free_sgl(struct scatterlist *sgl)
704 {
705 	while (sgl) {
706 		struct scatterlist *sg;
707 
708 		for (sg = sgl; !sg_is_chain(sg); sg++) {
709 			kfree(sg_virt(sg));
710 			if (sg_is_last(sg))
711 				break;
712 		}
713 
714 		sg = sg_is_last(sg) ? NULL : sg_chain_ptr(sg);
715 		free_page((unsigned long)sgl);
716 		sgl = sg;
717 	}
718 }
719 
720 static void err_print_gt_info(struct drm_i915_error_state_buf *m,
721 			      struct intel_gt_coredump *gt)
722 {
723 	struct drm_printer p = i915_error_printer(m);
724 
725 	intel_gt_info_print(&gt->info, &p);
726 	intel_sseu_print_topology(gt->_gt->i915, &gt->info.sseu, &p);
727 }
728 
729 static void err_print_gt_display(struct drm_i915_error_state_buf *m,
730 				 struct intel_gt_coredump *gt)
731 {
732 	err_printf(m, "IER: 0x%08x\n", gt->ier);
733 	err_printf(m, "DERRMR: 0x%08x\n", gt->derrmr);
734 }
735 
736 static void err_print_gt_global_nonguc(struct drm_i915_error_state_buf *m,
737 				       struct intel_gt_coredump *gt)
738 {
739 	int i;
740 
741 	err_printf(m, "GT awake: %s\n", str_yes_no(gt->awake));
742 	err_printf(m, "CS timestamp frequency: %u Hz, %d ns\n",
743 		   gt->clock_frequency, gt->clock_period_ns);
744 	err_printf(m, "EIR: 0x%08x\n", gt->eir);
745 	err_printf(m, "PGTBL_ER: 0x%08x\n", gt->pgtbl_er);
746 
747 	for (i = 0; i < gt->ngtier; i++)
748 		err_printf(m, "GTIER[%d]: 0x%08x\n", i, gt->gtier[i]);
749 }
750 
751 static void err_print_gt_global(struct drm_i915_error_state_buf *m,
752 				struct intel_gt_coredump *gt)
753 {
754 	err_printf(m, "FORCEWAKE: 0x%08x\n", gt->forcewake);
755 
756 	if (IS_GRAPHICS_VER(m->i915, 6, 11)) {
757 		err_printf(m, "ERROR: 0x%08x\n", gt->error);
758 		err_printf(m, "DONE_REG: 0x%08x\n", gt->done_reg);
759 	}
760 
761 	if (GRAPHICS_VER(m->i915) >= 8)
762 		err_printf(m, "FAULT_TLB_DATA: 0x%08x 0x%08x\n",
763 			   gt->fault_data1, gt->fault_data0);
764 
765 	if (GRAPHICS_VER(m->i915) == 7)
766 		err_printf(m, "ERR_INT: 0x%08x\n", gt->err_int);
767 
768 	if (IS_GRAPHICS_VER(m->i915, 8, 11))
769 		err_printf(m, "GTT_CACHE_EN: 0x%08x\n", gt->gtt_cache);
770 
771 	if (GRAPHICS_VER(m->i915) == 12)
772 		err_printf(m, "AUX_ERR_DBG: 0x%08x\n", gt->aux_err);
773 
774 	if (GRAPHICS_VER(m->i915) >= 12) {
775 		int i;
776 
777 		for (i = 0; i < I915_MAX_SFC; i++) {
778 			/*
779 			 * SFC_DONE resides in the VD forcewake domain, so it
780 			 * only exists if the corresponding VCS engine is
781 			 * present.
782 			 */
783 			if ((gt->_gt->info.sfc_mask & BIT(i)) == 0 ||
784 			    !HAS_ENGINE(gt->_gt, _VCS(i * 2)))
785 				continue;
786 
787 			err_printf(m, "  SFC_DONE[%d]: 0x%08x\n", i,
788 				   gt->sfc_done[i]);
789 		}
790 
791 		err_printf(m, "  GAM_DONE: 0x%08x\n", gt->gam_done);
792 	}
793 }
794 
795 static void err_print_gt_fences(struct drm_i915_error_state_buf *m,
796 				struct intel_gt_coredump *gt)
797 {
798 	int i;
799 
800 	for (i = 0; i < gt->nfence; i++)
801 		err_printf(m, "  fence[%d] = %08llx\n", i, gt->fence[i]);
802 }
803 
804 static void err_print_gt_engines(struct drm_i915_error_state_buf *m,
805 				 struct intel_gt_coredump *gt)
806 {
807 	const struct intel_engine_coredump *ee;
808 
809 	for (ee = gt->engine; ee; ee = ee->next) {
810 		const struct i915_vma_coredump *vma;
811 
812 		if (gt->uc && gt->uc->guc.is_guc_capture) {
813 			if (ee->guc_capture_node)
814 				intel_guc_capture_print_engine_node(m, ee);
815 			else
816 				err_printf(m, "  Missing GuC capture node for %s\n",
817 					   ee->engine->name);
818 		} else {
819 			error_print_engine(m, ee);
820 		}
821 
822 		err_printf(m, "  hung: %u\n", ee->hung);
823 		err_printf(m, "  engine reset count: %u\n", ee->reset_count);
824 		error_print_context(m, "  Active context: ", &ee->context);
825 
826 		for (vma = ee->vma; vma; vma = vma->next)
827 			intel_gpu_error_print_vma(m, ee->engine, vma);
828 	}
829 
830 }
831 
832 static void __err_print_to_sgl(struct drm_i915_error_state_buf *m,
833 			       struct i915_gpu_coredump *error)
834 {
835 	struct drm_printer p = i915_error_printer(m);
836 	const struct intel_engine_coredump *ee;
837 	struct timespec64 ts;
838 
839 	if (*error->error_msg)
840 		err_printf(m, "%s\n", error->error_msg);
841 	err_printf(m, "Kernel: %s %s\n",
842 		   init_utsname()->release,
843 		   init_utsname()->machine);
844 	err_printf(m, "Driver: %s\n", DRIVER_DATE);
845 	ts = ktime_to_timespec64(error->time);
846 	err_printf(m, "Time: %lld s %ld us\n",
847 		   (s64)ts.tv_sec, ts.tv_nsec / NSEC_PER_USEC);
848 	ts = ktime_to_timespec64(error->boottime);
849 	err_printf(m, "Boottime: %lld s %ld us\n",
850 		   (s64)ts.tv_sec, ts.tv_nsec / NSEC_PER_USEC);
851 	ts = ktime_to_timespec64(error->uptime);
852 	err_printf(m, "Uptime: %lld s %ld us\n",
853 		   (s64)ts.tv_sec, ts.tv_nsec / NSEC_PER_USEC);
854 	err_printf(m, "Capture: %lu jiffies; %d ms ago\n",
855 		   error->capture, jiffies_to_msecs(jiffies - error->capture));
856 
857 	for (ee = error->gt ? error->gt->engine : NULL; ee; ee = ee->next)
858 		err_printf(m, "Active process (on ring %s): %s [%d]\n",
859 			   ee->engine->name,
860 			   ee->context.comm,
861 			   ee->context.pid);
862 
863 	err_printf(m, "Reset count: %u\n", error->reset_count);
864 	err_printf(m, "Suspend count: %u\n", error->suspend_count);
865 	err_printf(m, "Platform: %s\n", intel_platform_name(error->device_info.platform));
866 	err_printf(m, "Subplatform: 0x%x\n",
867 		   intel_subplatform(&error->runtime_info,
868 				     error->device_info.platform));
869 	err_print_pciid(m, m->i915);
870 
871 	err_printf(m, "IOMMU enabled?: %d\n", error->iommu);
872 
873 	err_printf(m, "RPM wakelock: %s\n", str_yes_no(error->wakelock));
874 	err_printf(m, "PM suspended: %s\n", str_yes_no(error->suspended));
875 
876 	if (error->gt) {
877 		bool print_guc_capture = false;
878 
879 		if (error->gt->uc && error->gt->uc->guc.is_guc_capture)
880 			print_guc_capture = true;
881 
882 		err_print_gt_display(m, error->gt);
883 		err_print_gt_global_nonguc(m, error->gt);
884 		err_print_gt_fences(m, error->gt);
885 
886 		/*
887 		 * GuC dumped global, eng-class and eng-instance registers together
888 		 * as part of engine state dump so we print in err_print_gt_engines
889 		 */
890 		if (!print_guc_capture)
891 			err_print_gt_global(m, error->gt);
892 
893 		err_print_gt_engines(m, error->gt);
894 
895 		if (error->gt->uc)
896 			err_print_uc(m, error->gt->uc);
897 
898 		err_print_gt_info(m, error->gt);
899 	}
900 
901 	err_print_capabilities(m, error);
902 	err_print_params(m, &error->params);
903 
904 	intel_display_snapshot_print(error->display_snapshot, &p);
905 }
906 
907 static int err_print_to_sgl(struct i915_gpu_coredump *error)
908 {
909 	struct drm_i915_error_state_buf m;
910 
911 	if (IS_ERR(error))
912 		return PTR_ERR(error);
913 
914 	if (READ_ONCE(error->sgl))
915 		return 0;
916 
917 	memset(&m, 0, sizeof(m));
918 	m.i915 = error->i915;
919 
920 	__err_print_to_sgl(&m, error);
921 
922 	if (m.buf) {
923 		__sg_set_buf(m.cur++, m.buf, m.bytes, m.iter);
924 		m.bytes = 0;
925 		m.buf = NULL;
926 	}
927 	if (m.cur) {
928 		GEM_BUG_ON(m.end < m.cur);
929 		sg_mark_end(m.cur - 1);
930 	}
931 	GEM_BUG_ON(m.sgl && !m.cur);
932 
933 	if (m.err) {
934 		err_free_sgl(m.sgl);
935 		return m.err;
936 	}
937 
938 	if (cmpxchg(&error->sgl, NULL, m.sgl))
939 		err_free_sgl(m.sgl);
940 
941 	return 0;
942 }
943 
944 ssize_t i915_gpu_coredump_copy_to_buffer(struct i915_gpu_coredump *error,
945 					 char *buf, loff_t off, size_t rem)
946 {
947 	struct scatterlist *sg;
948 	size_t count;
949 	loff_t pos;
950 	int err;
951 
952 	if (!error || !rem)
953 		return 0;
954 
955 	err = err_print_to_sgl(error);
956 	if (err)
957 		return err;
958 
959 	sg = READ_ONCE(error->fit);
960 	if (!sg || off < sg->dma_address)
961 		sg = error->sgl;
962 	if (!sg)
963 		return 0;
964 
965 	pos = sg->dma_address;
966 	count = 0;
967 	do {
968 		size_t len, start;
969 
970 		if (sg_is_chain(sg)) {
971 			sg = sg_chain_ptr(sg);
972 			GEM_BUG_ON(sg_is_chain(sg));
973 		}
974 
975 		len = sg->length;
976 		if (pos + len <= off) {
977 			pos += len;
978 			continue;
979 		}
980 
981 		start = sg->offset;
982 		if (pos < off) {
983 			GEM_BUG_ON(off - pos > len);
984 			len -= off - pos;
985 			start += off - pos;
986 			pos = off;
987 		}
988 
989 		len = min(len, rem);
990 		GEM_BUG_ON(!len || len > sg->length);
991 
992 		memcpy(buf, page_address(sg_page(sg)) + start, len);
993 
994 		count += len;
995 		pos += len;
996 
997 		buf += len;
998 		rem -= len;
999 		if (!rem) {
1000 			WRITE_ONCE(error->fit, sg);
1001 			break;
1002 		}
1003 	} while (!sg_is_last(sg++));
1004 
1005 	return count;
1006 }
1007 
1008 static void i915_vma_coredump_free(struct i915_vma_coredump *vma)
1009 {
1010 	while (vma) {
1011 		struct i915_vma_coredump *next = vma->next;
1012 		struct page *page, *n;
1013 
1014 		list_for_each_entry_safe(page, n, &vma->page_list, lru) {
1015 			list_del_init(&page->lru);
1016 			__free_page(page);
1017 		}
1018 
1019 		kfree(vma);
1020 		vma = next;
1021 	}
1022 }
1023 
1024 static void cleanup_params(struct i915_gpu_coredump *error)
1025 {
1026 	i915_params_free(&error->params);
1027 }
1028 
1029 static void cleanup_uc(struct intel_uc_coredump *uc)
1030 {
1031 	kfree(uc->guc_fw.file_selected.path);
1032 	kfree(uc->huc_fw.file_selected.path);
1033 	kfree(uc->guc_fw.file_wanted.path);
1034 	kfree(uc->huc_fw.file_wanted.path);
1035 	i915_vma_coredump_free(uc->guc.vma_log);
1036 	i915_vma_coredump_free(uc->guc.vma_ctb);
1037 
1038 	kfree(uc);
1039 }
1040 
1041 static void cleanup_gt(struct intel_gt_coredump *gt)
1042 {
1043 	while (gt->engine) {
1044 		struct intel_engine_coredump *ee = gt->engine;
1045 
1046 		gt->engine = ee->next;
1047 
1048 		i915_vma_coredump_free(ee->vma);
1049 		intel_guc_capture_free_node(ee);
1050 		kfree(ee);
1051 	}
1052 
1053 	if (gt->uc)
1054 		cleanup_uc(gt->uc);
1055 
1056 	kfree(gt);
1057 }
1058 
1059 void __i915_gpu_coredump_free(struct kref *error_ref)
1060 {
1061 	struct i915_gpu_coredump *error =
1062 		container_of(error_ref, typeof(*error), ref);
1063 
1064 	while (error->gt) {
1065 		struct intel_gt_coredump *gt = error->gt;
1066 
1067 		error->gt = gt->next;
1068 		cleanup_gt(gt);
1069 	}
1070 
1071 	intel_display_snapshot_free(error->display_snapshot);
1072 
1073 	cleanup_params(error);
1074 
1075 	err_free_sgl(error->sgl);
1076 	kfree(error);
1077 }
1078 
1079 static struct i915_vma_coredump *
1080 i915_vma_coredump_create(const struct intel_gt *gt,
1081 			 const struct i915_vma_resource *vma_res,
1082 			 struct i915_vma_compress *compress,
1083 			 const char *name)
1084 
1085 {
1086 	struct i915_ggtt *ggtt = gt->ggtt;
1087 	const u64 slot = ggtt->error_capture.start;
1088 	struct i915_vma_coredump *dst;
1089 	struct sgt_iter iter;
1090 	int ret;
1091 
1092 	might_sleep();
1093 
1094 	if (!vma_res || !vma_res->bi.pages || !compress)
1095 		return NULL;
1096 
1097 	dst = kmalloc(sizeof(*dst), ALLOW_FAIL);
1098 	if (!dst)
1099 		return NULL;
1100 
1101 	if (!compress_start(compress)) {
1102 		kfree(dst);
1103 		return NULL;
1104 	}
1105 
1106 	INIT_LIST_HEAD(&dst->page_list);
1107 	strscpy(dst->name, name);
1108 	dst->next = NULL;
1109 
1110 	dst->gtt_offset = vma_res->start;
1111 	dst->gtt_size = vma_res->node_size;
1112 	dst->gtt_page_sizes = vma_res->page_sizes_gtt;
1113 	dst->unused = 0;
1114 
1115 	ret = -EINVAL;
1116 	if (drm_mm_node_allocated(&ggtt->error_capture)) {
1117 		void __iomem *s;
1118 		dma_addr_t dma;
1119 
1120 		for_each_sgt_daddr(dma, iter, vma_res->bi.pages) {
1121 			mutex_lock(&ggtt->error_mutex);
1122 			if (ggtt->vm.raw_insert_page)
1123 				ggtt->vm.raw_insert_page(&ggtt->vm, dma, slot,
1124 							 i915_gem_get_pat_index(gt->i915,
1125 										I915_CACHE_NONE),
1126 							 0);
1127 			else
1128 				ggtt->vm.insert_page(&ggtt->vm, dma, slot,
1129 						     i915_gem_get_pat_index(gt->i915,
1130 									    I915_CACHE_NONE),
1131 						     0);
1132 			mb();
1133 
1134 			s = io_mapping_map_wc(&ggtt->iomap, slot, PAGE_SIZE);
1135 			ret = compress_page(compress,
1136 					    (void  __force *)s, dst,
1137 					    true);
1138 			io_mapping_unmap(s);
1139 
1140 			mb();
1141 			ggtt->vm.clear_range(&ggtt->vm, slot, PAGE_SIZE);
1142 			mutex_unlock(&ggtt->error_mutex);
1143 			if (ret)
1144 				break;
1145 		}
1146 	} else if (vma_res->bi.lmem) {
1147 		struct intel_memory_region *mem = vma_res->mr;
1148 		dma_addr_t dma;
1149 
1150 		for_each_sgt_daddr(dma, iter, vma_res->bi.pages) {
1151 			dma_addr_t offset = dma - mem->region.start;
1152 			void __iomem *s;
1153 
1154 			if (offset + PAGE_SIZE > resource_size(&mem->io)) {
1155 				ret = -EINVAL;
1156 				break;
1157 			}
1158 
1159 			s = io_mapping_map_wc(&mem->iomap, offset, PAGE_SIZE);
1160 			ret = compress_page(compress,
1161 					    (void __force *)s, dst,
1162 					    true);
1163 			io_mapping_unmap(s);
1164 			if (ret)
1165 				break;
1166 		}
1167 	} else {
1168 		struct page *page;
1169 
1170 		for_each_sgt_page(page, iter, vma_res->bi.pages) {
1171 			void *s;
1172 
1173 			drm_clflush_pages(&page, 1);
1174 
1175 			s = kmap_local_page(page);
1176 			ret = compress_page(compress, s, dst, false);
1177 			kunmap_local(s);
1178 
1179 			drm_clflush_pages(&page, 1);
1180 
1181 			if (ret)
1182 				break;
1183 		}
1184 	}
1185 
1186 	if (ret || compress_flush(compress, dst)) {
1187 		struct page *page, *n;
1188 
1189 		list_for_each_entry_safe_reverse(page, n, &dst->page_list, lru) {
1190 			list_del_init(&page->lru);
1191 			pool_free(&compress->pool, page_address(page));
1192 		}
1193 
1194 		kfree(dst);
1195 		dst = NULL;
1196 	}
1197 	compress_finish(compress);
1198 
1199 	return dst;
1200 }
1201 
1202 static void gt_record_fences(struct intel_gt_coredump *gt)
1203 {
1204 	struct i915_ggtt *ggtt = gt->_gt->ggtt;
1205 	struct intel_uncore *uncore = gt->_gt->uncore;
1206 	int i;
1207 
1208 	if (GRAPHICS_VER(uncore->i915) >= 6) {
1209 		for (i = 0; i < ggtt->num_fences; i++)
1210 			gt->fence[i] =
1211 				intel_uncore_read64(uncore,
1212 						    FENCE_REG_GEN6_LO(i));
1213 	} else if (GRAPHICS_VER(uncore->i915) >= 4) {
1214 		for (i = 0; i < ggtt->num_fences; i++)
1215 			gt->fence[i] =
1216 				intel_uncore_read64(uncore,
1217 						    FENCE_REG_965_LO(i));
1218 	} else {
1219 		for (i = 0; i < ggtt->num_fences; i++)
1220 			gt->fence[i] =
1221 				intel_uncore_read(uncore, FENCE_REG(i));
1222 	}
1223 	gt->nfence = i;
1224 }
1225 
1226 static void engine_record_registers(struct intel_engine_coredump *ee)
1227 {
1228 	const struct intel_engine_cs *engine = ee->engine;
1229 	struct drm_i915_private *i915 = engine->i915;
1230 
1231 	if (GRAPHICS_VER(i915) >= 6) {
1232 		ee->rc_psmi = ENGINE_READ(engine, RING_PSMI_CTL);
1233 
1234 		/*
1235 		 * For the media GT, this ring fault register is not replicated,
1236 		 * so don't do multicast/replicated register read/write
1237 		 * operation on it.
1238 		 */
1239 		if (MEDIA_VER(i915) >= 13 && engine->gt->type == GT_MEDIA)
1240 			ee->fault_reg = intel_uncore_read(engine->uncore,
1241 							  XELPMP_RING_FAULT_REG);
1242 		else if (GRAPHICS_VER_FULL(i915) >= IP_VER(12, 55))
1243 			ee->fault_reg = intel_gt_mcr_read_any(engine->gt,
1244 							      XEHP_RING_FAULT_REG);
1245 		else if (GRAPHICS_VER(i915) >= 12)
1246 			ee->fault_reg = intel_uncore_read(engine->uncore,
1247 							  GEN12_RING_FAULT_REG);
1248 		else if (GRAPHICS_VER(i915) >= 8)
1249 			ee->fault_reg = intel_uncore_read(engine->uncore,
1250 							  GEN8_RING_FAULT_REG);
1251 		else
1252 			ee->fault_reg = GEN6_RING_FAULT_REG_READ(engine);
1253 	}
1254 
1255 	if (GRAPHICS_VER(i915) >= 4) {
1256 		ee->esr = ENGINE_READ(engine, RING_ESR);
1257 		ee->faddr = ENGINE_READ(engine, RING_DMA_FADD);
1258 		ee->ipeir = ENGINE_READ(engine, RING_IPEIR);
1259 		ee->ipehr = ENGINE_READ(engine, RING_IPEHR);
1260 		ee->instps = ENGINE_READ(engine, RING_INSTPS);
1261 		ee->bbaddr = ENGINE_READ(engine, RING_BBADDR);
1262 		ee->ccid = ENGINE_READ(engine, CCID);
1263 		if (GRAPHICS_VER(i915) >= 8) {
1264 			ee->faddr |= (u64)ENGINE_READ(engine, RING_DMA_FADD_UDW) << 32;
1265 			ee->bbaddr |= (u64)ENGINE_READ(engine, RING_BBADDR_UDW) << 32;
1266 		}
1267 		ee->bbstate = ENGINE_READ(engine, RING_BBSTATE);
1268 	} else {
1269 		ee->faddr = ENGINE_READ(engine, DMA_FADD_I8XX);
1270 		ee->ipeir = ENGINE_READ(engine, IPEIR);
1271 		ee->ipehr = ENGINE_READ(engine, IPEHR);
1272 	}
1273 
1274 	if (GRAPHICS_VER(i915) >= 11) {
1275 		ee->cmd_cctl = ENGINE_READ(engine, RING_CMD_CCTL);
1276 		ee->cscmdop = ENGINE_READ(engine, RING_CSCMDOP);
1277 		ee->ctx_sr_ctl = ENGINE_READ(engine, RING_CTX_SR_CTL);
1278 		ee->dma_faddr_hi = ENGINE_READ(engine, RING_DMA_FADD_UDW);
1279 		ee->dma_faddr_lo = ENGINE_READ(engine, RING_DMA_FADD);
1280 		ee->nopid = ENGINE_READ(engine, RING_NOPID);
1281 		ee->excc = ENGINE_READ(engine, RING_EXCC);
1282 	}
1283 
1284 	intel_engine_get_instdone(engine, &ee->instdone);
1285 
1286 	ee->instpm = ENGINE_READ(engine, RING_INSTPM);
1287 	ee->acthd = intel_engine_get_active_head(engine);
1288 	ee->start = ENGINE_READ(engine, RING_START);
1289 	ee->head = ENGINE_READ(engine, RING_HEAD);
1290 	ee->tail = ENGINE_READ(engine, RING_TAIL);
1291 	ee->ctl = ENGINE_READ(engine, RING_CTL);
1292 	if (GRAPHICS_VER(i915) > 2)
1293 		ee->mode = ENGINE_READ(engine, RING_MI_MODE);
1294 
1295 	if (!HWS_NEEDS_PHYSICAL(i915)) {
1296 		i915_reg_t mmio;
1297 
1298 		if (GRAPHICS_VER(i915) == 7) {
1299 			switch (engine->id) {
1300 			default:
1301 				MISSING_CASE(engine->id);
1302 				fallthrough;
1303 			case RCS0:
1304 				mmio = RENDER_HWS_PGA_GEN7;
1305 				break;
1306 			case BCS0:
1307 				mmio = BLT_HWS_PGA_GEN7;
1308 				break;
1309 			case VCS0:
1310 				mmio = BSD_HWS_PGA_GEN7;
1311 				break;
1312 			case VECS0:
1313 				mmio = VEBOX_HWS_PGA_GEN7;
1314 				break;
1315 			}
1316 		} else if (GRAPHICS_VER(engine->i915) == 6) {
1317 			mmio = RING_HWS_PGA_GEN6(engine->mmio_base);
1318 		} else {
1319 			/* XXX: gen8 returns to sanity */
1320 			mmio = RING_HWS_PGA(engine->mmio_base);
1321 		}
1322 
1323 		ee->hws = intel_uncore_read(engine->uncore, mmio);
1324 	}
1325 
1326 	ee->reset_count = i915_reset_engine_count(&i915->gpu_error, engine);
1327 
1328 	if (HAS_PPGTT(i915)) {
1329 		int i;
1330 
1331 		ee->vm_info.gfx_mode = ENGINE_READ(engine, RING_MODE_GEN7);
1332 
1333 		if (GRAPHICS_VER(i915) == 6) {
1334 			ee->vm_info.pp_dir_base =
1335 				ENGINE_READ(engine, RING_PP_DIR_BASE_READ);
1336 		} else if (GRAPHICS_VER(i915) == 7) {
1337 			ee->vm_info.pp_dir_base =
1338 				ENGINE_READ(engine, RING_PP_DIR_BASE);
1339 		} else if (GRAPHICS_VER(i915) >= 8) {
1340 			u32 base = engine->mmio_base;
1341 
1342 			for (i = 0; i < 4; i++) {
1343 				ee->vm_info.pdp[i] =
1344 					intel_uncore_read(engine->uncore,
1345 							  GEN8_RING_PDP_UDW(base, i));
1346 				ee->vm_info.pdp[i] <<= 32;
1347 				ee->vm_info.pdp[i] |=
1348 					intel_uncore_read(engine->uncore,
1349 							  GEN8_RING_PDP_LDW(base, i));
1350 			}
1351 		}
1352 	}
1353 }
1354 
1355 static void record_request(const struct i915_request *request,
1356 			   struct i915_request_coredump *erq)
1357 {
1358 	erq->flags = request->fence.flags;
1359 	erq->context = request->fence.context;
1360 	erq->seqno = request->fence.seqno;
1361 	erq->sched_attr = request->sched.attr;
1362 	erq->head = request->head;
1363 	erq->tail = request->tail;
1364 
1365 	erq->pid = 0;
1366 	rcu_read_lock();
1367 	if (!intel_context_is_closed(request->context)) {
1368 		const struct i915_gem_context *ctx;
1369 
1370 		ctx = rcu_dereference(request->context->gem_context);
1371 		if (ctx)
1372 			erq->pid = pid_nr(ctx->pid);
1373 	}
1374 	rcu_read_unlock();
1375 }
1376 
1377 static void engine_record_execlists(struct intel_engine_coredump *ee)
1378 {
1379 	const struct intel_engine_execlists * const el = &ee->engine->execlists;
1380 	struct i915_request * const *port = el->active;
1381 	unsigned int n = 0;
1382 
1383 	while (*port)
1384 		record_request(*port++, &ee->execlist[n++]);
1385 
1386 	ee->num_ports = n;
1387 }
1388 
1389 static bool record_context(struct i915_gem_context_coredump *e,
1390 			   struct intel_context *ce)
1391 {
1392 	struct i915_gem_context *ctx;
1393 	struct task_struct *task;
1394 	bool simulated;
1395 
1396 	rcu_read_lock();
1397 	ctx = rcu_dereference(ce->gem_context);
1398 	if (ctx && !kref_get_unless_zero(&ctx->ref))
1399 		ctx = NULL;
1400 	rcu_read_unlock();
1401 	if (!ctx)
1402 		return true;
1403 
1404 	rcu_read_lock();
1405 	task = pid_task(ctx->pid, PIDTYPE_PID);
1406 	if (task) {
1407 		strscpy(e->comm, task->comm);
1408 		e->pid = task->pid;
1409 	}
1410 	rcu_read_unlock();
1411 
1412 	e->sched_attr = ctx->sched;
1413 	e->guilty = atomic_read(&ctx->guilty_count);
1414 	e->active = atomic_read(&ctx->active_count);
1415 	e->hwsp_seqno = (ce->timeline && ce->timeline->hwsp_seqno) ?
1416 				*ce->timeline->hwsp_seqno : ~0U;
1417 
1418 	e->total_runtime = intel_context_get_total_runtime_ns(ce);
1419 	e->avg_runtime = intel_context_get_avg_runtime_ns(ce);
1420 
1421 	simulated = i915_gem_context_no_error_capture(ctx);
1422 
1423 	i915_gem_context_put(ctx);
1424 	return simulated;
1425 }
1426 
1427 struct intel_engine_capture_vma {
1428 	struct intel_engine_capture_vma *next;
1429 	struct i915_vma_resource *vma_res;
1430 	char name[16];
1431 	bool lockdep_cookie;
1432 };
1433 
1434 static struct intel_engine_capture_vma *
1435 capture_vma_snapshot(struct intel_engine_capture_vma *next,
1436 		     struct i915_vma_resource *vma_res,
1437 		     gfp_t gfp, const char *name)
1438 {
1439 	struct intel_engine_capture_vma *c;
1440 
1441 	if (!vma_res)
1442 		return next;
1443 
1444 	c = kmalloc(sizeof(*c), gfp);
1445 	if (!c)
1446 		return next;
1447 
1448 	if (!i915_vma_resource_hold(vma_res, &c->lockdep_cookie)) {
1449 		kfree(c);
1450 		return next;
1451 	}
1452 
1453 	strscpy(c->name, name);
1454 	c->vma_res = i915_vma_resource_get(vma_res);
1455 
1456 	c->next = next;
1457 	return c;
1458 }
1459 
1460 static struct intel_engine_capture_vma *
1461 capture_vma(struct intel_engine_capture_vma *next,
1462 	    struct i915_vma *vma,
1463 	    const char *name,
1464 	    gfp_t gfp)
1465 {
1466 	if (!vma)
1467 		return next;
1468 
1469 	/*
1470 	 * If the vma isn't pinned, then the vma should be snapshotted
1471 	 * to a struct i915_vma_snapshot at command submission time.
1472 	 * Not here.
1473 	 */
1474 	if (GEM_WARN_ON(!i915_vma_is_pinned(vma)))
1475 		return next;
1476 
1477 	next = capture_vma_snapshot(next, vma->resource, gfp, name);
1478 
1479 	return next;
1480 }
1481 
1482 static struct intel_engine_capture_vma *
1483 capture_user(struct intel_engine_capture_vma *capture,
1484 	     const struct i915_request *rq,
1485 	     gfp_t gfp)
1486 {
1487 	struct i915_capture_list *c;
1488 
1489 	for (c = rq->capture_list; c; c = c->next)
1490 		capture = capture_vma_snapshot(capture, c->vma_res, gfp,
1491 					       "user");
1492 
1493 	return capture;
1494 }
1495 
1496 static void add_vma(struct intel_engine_coredump *ee,
1497 		    struct i915_vma_coredump *vma)
1498 {
1499 	if (vma) {
1500 		vma->next = ee->vma;
1501 		ee->vma = vma;
1502 	}
1503 }
1504 
1505 static struct i915_vma_coredump *
1506 create_vma_coredump(const struct intel_gt *gt, struct i915_vma *vma,
1507 		    const char *name, struct i915_vma_compress *compress)
1508 {
1509 	struct i915_vma_coredump *ret = NULL;
1510 	struct i915_vma_resource *vma_res;
1511 	bool lockdep_cookie;
1512 
1513 	if (!vma)
1514 		return NULL;
1515 
1516 	vma_res = vma->resource;
1517 
1518 	if (i915_vma_resource_hold(vma_res, &lockdep_cookie)) {
1519 		ret = i915_vma_coredump_create(gt, vma_res, compress, name);
1520 		i915_vma_resource_unhold(vma_res, lockdep_cookie);
1521 	}
1522 
1523 	return ret;
1524 }
1525 
1526 static void add_vma_coredump(struct intel_engine_coredump *ee,
1527 			     const struct intel_gt *gt,
1528 			     struct i915_vma *vma,
1529 			     const char *name,
1530 			     struct i915_vma_compress *compress)
1531 {
1532 	add_vma(ee, create_vma_coredump(gt, vma, name, compress));
1533 }
1534 
1535 struct intel_engine_coredump *
1536 intel_engine_coredump_alloc(struct intel_engine_cs *engine, gfp_t gfp, u32 dump_flags)
1537 {
1538 	struct intel_engine_coredump *ee;
1539 
1540 	ee = kzalloc(sizeof(*ee), gfp);
1541 	if (!ee)
1542 		return NULL;
1543 
1544 	ee->engine = engine;
1545 
1546 	if (!(dump_flags & CORE_DUMP_FLAG_IS_GUC_CAPTURE)) {
1547 		engine_record_registers(ee);
1548 		engine_record_execlists(ee);
1549 	}
1550 
1551 	return ee;
1552 }
1553 
1554 static struct intel_engine_capture_vma *
1555 engine_coredump_add_context(struct intel_engine_coredump *ee,
1556 			    struct intel_context *ce,
1557 			    gfp_t gfp)
1558 {
1559 	struct intel_engine_capture_vma *vma = NULL;
1560 
1561 	ee->simulated |= record_context(&ee->context, ce);
1562 	if (ee->simulated)
1563 		return NULL;
1564 
1565 	/*
1566 	 * We need to copy these to an anonymous buffer
1567 	 * as the simplest method to avoid being overwritten
1568 	 * by userspace.
1569 	 */
1570 	vma = capture_vma(vma, ce->ring->vma, "ring", gfp);
1571 	vma = capture_vma(vma, ce->state, "HW context", gfp);
1572 
1573 	return vma;
1574 }
1575 
1576 struct intel_engine_capture_vma *
1577 intel_engine_coredump_add_request(struct intel_engine_coredump *ee,
1578 				  struct i915_request *rq,
1579 				  gfp_t gfp)
1580 {
1581 	struct intel_engine_capture_vma *vma;
1582 
1583 	vma = engine_coredump_add_context(ee, rq->context, gfp);
1584 	if (!vma)
1585 		return NULL;
1586 
1587 	/*
1588 	 * We need to copy these to an anonymous buffer
1589 	 * as the simplest method to avoid being overwritten
1590 	 * by userspace.
1591 	 */
1592 	vma = capture_vma_snapshot(vma, rq->batch_res, gfp, "batch");
1593 	vma = capture_user(vma, rq, gfp);
1594 
1595 	ee->rq_head = rq->head;
1596 	ee->rq_post = rq->postfix;
1597 	ee->rq_tail = rq->tail;
1598 
1599 	return vma;
1600 }
1601 
1602 void
1603 intel_engine_coredump_add_vma(struct intel_engine_coredump *ee,
1604 			      struct intel_engine_capture_vma *capture,
1605 			      struct i915_vma_compress *compress)
1606 {
1607 	const struct intel_engine_cs *engine = ee->engine;
1608 
1609 	while (capture) {
1610 		struct intel_engine_capture_vma *this = capture;
1611 		struct i915_vma_resource *vma_res = this->vma_res;
1612 
1613 		add_vma(ee,
1614 			i915_vma_coredump_create(engine->gt, vma_res,
1615 						 compress, this->name));
1616 
1617 		i915_vma_resource_unhold(vma_res, this->lockdep_cookie);
1618 		i915_vma_resource_put(vma_res);
1619 
1620 		capture = this->next;
1621 		kfree(this);
1622 	}
1623 
1624 	add_vma_coredump(ee, engine->gt, engine->status_page.vma,
1625 			 "HW Status", compress);
1626 
1627 	add_vma_coredump(ee, engine->gt, engine->wa_ctx.vma,
1628 			 "WA context", compress);
1629 }
1630 
1631 static struct intel_engine_coredump *
1632 capture_engine(struct intel_engine_cs *engine,
1633 	       struct i915_vma_compress *compress,
1634 	       u32 dump_flags)
1635 {
1636 	struct intel_engine_capture_vma *capture = NULL;
1637 	struct intel_engine_coredump *ee;
1638 	struct intel_context *ce = NULL;
1639 	struct i915_request *rq = NULL;
1640 
1641 	ee = intel_engine_coredump_alloc(engine, ALLOW_FAIL, dump_flags);
1642 	if (!ee)
1643 		return NULL;
1644 
1645 	intel_engine_get_hung_entity(engine, &ce, &rq);
1646 	if (rq && !i915_request_started(rq))
1647 		drm_info(&engine->gt->i915->drm, "Got hung context on %s with active request %lld:%lld [0x%04X] not yet started\n",
1648 			 engine->name, rq->fence.context, rq->fence.seqno, ce->guc_id.id);
1649 
1650 	if (rq) {
1651 		capture = intel_engine_coredump_add_request(ee, rq, ATOMIC_MAYFAIL);
1652 		i915_request_put(rq);
1653 	} else if (ce) {
1654 		capture = engine_coredump_add_context(ee, ce, ATOMIC_MAYFAIL);
1655 	}
1656 
1657 	if (capture) {
1658 		intel_engine_coredump_add_vma(ee, capture, compress);
1659 
1660 		if (dump_flags & CORE_DUMP_FLAG_IS_GUC_CAPTURE)
1661 			intel_guc_capture_get_matching_node(engine->gt, ee, ce);
1662 	} else {
1663 		kfree(ee);
1664 		ee = NULL;
1665 	}
1666 
1667 	return ee;
1668 }
1669 
1670 static void
1671 gt_record_engines(struct intel_gt_coredump *gt,
1672 		  intel_engine_mask_t engine_mask,
1673 		  struct i915_vma_compress *compress,
1674 		  u32 dump_flags)
1675 {
1676 	struct intel_engine_cs *engine;
1677 	enum intel_engine_id id;
1678 
1679 	for_each_engine(engine, gt->_gt, id) {
1680 		struct intel_engine_coredump *ee;
1681 
1682 		/* Refill our page pool before entering atomic section */
1683 		pool_refill(&compress->pool, ALLOW_FAIL);
1684 
1685 		ee = capture_engine(engine, compress, dump_flags);
1686 		if (!ee)
1687 			continue;
1688 
1689 		ee->hung = engine->mask & engine_mask;
1690 
1691 		gt->simulated |= ee->simulated;
1692 		if (ee->simulated) {
1693 			if (dump_flags & CORE_DUMP_FLAG_IS_GUC_CAPTURE)
1694 				intel_guc_capture_free_node(ee);
1695 			kfree(ee);
1696 			continue;
1697 		}
1698 
1699 		ee->next = gt->engine;
1700 		gt->engine = ee;
1701 	}
1702 }
1703 
1704 static void gt_record_guc_ctb(struct intel_ctb_coredump *saved,
1705 			      const struct intel_guc_ct_buffer *ctb,
1706 			      const void *blob_ptr, struct intel_guc *guc)
1707 {
1708 	if (!ctb || !ctb->desc)
1709 		return;
1710 
1711 	saved->raw_status = ctb->desc->status;
1712 	saved->raw_head = ctb->desc->head;
1713 	saved->raw_tail = ctb->desc->tail;
1714 	saved->head = ctb->head;
1715 	saved->tail = ctb->tail;
1716 	saved->size = ctb->size;
1717 	saved->desc_offset = ((void *)ctb->desc) - blob_ptr;
1718 	saved->cmds_offset = ((void *)ctb->cmds) - blob_ptr;
1719 }
1720 
1721 static struct intel_uc_coredump *
1722 gt_record_uc(struct intel_gt_coredump *gt,
1723 	     struct i915_vma_compress *compress)
1724 {
1725 	const struct intel_uc *uc = &gt->_gt->uc;
1726 	struct intel_uc_coredump *error_uc;
1727 
1728 	error_uc = kzalloc(sizeof(*error_uc), ALLOW_FAIL);
1729 	if (!error_uc)
1730 		return NULL;
1731 
1732 	memcpy(&error_uc->guc_fw, &uc->guc.fw, sizeof(uc->guc.fw));
1733 	memcpy(&error_uc->huc_fw, &uc->huc.fw, sizeof(uc->huc.fw));
1734 
1735 	error_uc->guc_fw.file_selected.path = kstrdup(uc->guc.fw.file_selected.path, ALLOW_FAIL);
1736 	error_uc->huc_fw.file_selected.path = kstrdup(uc->huc.fw.file_selected.path, ALLOW_FAIL);
1737 	error_uc->guc_fw.file_wanted.path = kstrdup(uc->guc.fw.file_wanted.path, ALLOW_FAIL);
1738 	error_uc->huc_fw.file_wanted.path = kstrdup(uc->huc.fw.file_wanted.path, ALLOW_FAIL);
1739 
1740 	/*
1741 	 * Save the GuC log and include a timestamp reference for converting the
1742 	 * log times to system times (in conjunction with the error->boottime and
1743 	 * gt->clock_frequency fields saved elsewhere).
1744 	 */
1745 	error_uc->guc.timestamp = intel_uncore_read(gt->_gt->uncore, GUCPMTIMESTAMP);
1746 	error_uc->guc.vma_log = create_vma_coredump(gt->_gt, uc->guc.log.vma,
1747 						    "GuC log buffer", compress);
1748 	error_uc->guc.vma_ctb = create_vma_coredump(gt->_gt, uc->guc.ct.vma,
1749 						    "GuC CT buffer", compress);
1750 	error_uc->guc.last_fence = uc->guc.ct.requests.last_fence;
1751 	gt_record_guc_ctb(error_uc->guc.ctb + 0, &uc->guc.ct.ctbs.send,
1752 			  uc->guc.ct.ctbs.send.desc, (struct intel_guc *)&uc->guc);
1753 	gt_record_guc_ctb(error_uc->guc.ctb + 1, &uc->guc.ct.ctbs.recv,
1754 			  uc->guc.ct.ctbs.send.desc, (struct intel_guc *)&uc->guc);
1755 
1756 	return error_uc;
1757 }
1758 
1759 /* Capture display registers. */
1760 static void gt_record_display_regs(struct intel_gt_coredump *gt)
1761 {
1762 	struct intel_uncore *uncore = gt->_gt->uncore;
1763 	struct drm_i915_private *i915 = uncore->i915;
1764 
1765 	if (DISPLAY_VER(i915) >= 6 && DISPLAY_VER(i915) < 20)
1766 		gt->derrmr = intel_uncore_read(uncore, DERRMR);
1767 
1768 	if (GRAPHICS_VER(i915) >= 8)
1769 		gt->ier = intel_uncore_read(uncore, GEN8_DE_MISC_IER);
1770 	else if (IS_VALLEYVIEW(i915))
1771 		gt->ier = intel_uncore_read(uncore, VLV_IER);
1772 	else if (HAS_PCH_SPLIT(i915))
1773 		gt->ier = intel_uncore_read(uncore, DEIER);
1774 	else if (GRAPHICS_VER(i915) == 2)
1775 		gt->ier = intel_uncore_read16(uncore, GEN2_IER);
1776 	else
1777 		gt->ier = intel_uncore_read(uncore, GEN2_IER);
1778 }
1779 
1780 /* Capture all other registers that GuC doesn't capture. */
1781 static void gt_record_global_nonguc_regs(struct intel_gt_coredump *gt)
1782 {
1783 	struct intel_uncore *uncore = gt->_gt->uncore;
1784 	struct drm_i915_private *i915 = uncore->i915;
1785 	int i;
1786 
1787 	if (IS_VALLEYVIEW(i915)) {
1788 		gt->gtier[0] = intel_uncore_read(uncore, GTIER);
1789 		gt->ngtier = 1;
1790 	} else if (GRAPHICS_VER(i915) >= 11) {
1791 		gt->gtier[0] =
1792 			intel_uncore_read(uncore,
1793 					  GEN11_RENDER_COPY_INTR_ENABLE);
1794 		gt->gtier[1] =
1795 			intel_uncore_read(uncore, GEN11_VCS_VECS_INTR_ENABLE);
1796 		gt->gtier[2] =
1797 			intel_uncore_read(uncore, GEN11_GUC_SG_INTR_ENABLE);
1798 		gt->gtier[3] =
1799 			intel_uncore_read(uncore,
1800 					  GEN11_GPM_WGBOXPERF_INTR_ENABLE);
1801 		gt->gtier[4] =
1802 			intel_uncore_read(uncore,
1803 					  GEN11_CRYPTO_RSVD_INTR_ENABLE);
1804 		gt->gtier[5] =
1805 			intel_uncore_read(uncore,
1806 					  GEN11_GUNIT_CSME_INTR_ENABLE);
1807 		gt->ngtier = 6;
1808 	} else if (GRAPHICS_VER(i915) >= 8) {
1809 		for (i = 0; i < 4; i++)
1810 			gt->gtier[i] =
1811 				intel_uncore_read(uncore, GEN8_GT_IER(i));
1812 		gt->ngtier = 4;
1813 	} else if (HAS_PCH_SPLIT(i915)) {
1814 		gt->gtier[0] = intel_uncore_read(uncore, GTIER);
1815 		gt->ngtier = 1;
1816 	}
1817 
1818 	gt->eir = intel_uncore_read(uncore, EIR);
1819 	gt->pgtbl_er = intel_uncore_read(uncore, PGTBL_ER);
1820 }
1821 
1822 /*
1823  * Capture all registers that relate to workload submission.
1824  * NOTE: In GuC submission, when GuC resets an engine, it can dump these for us
1825  */
1826 static void gt_record_global_regs(struct intel_gt_coredump *gt)
1827 {
1828 	struct intel_uncore *uncore = gt->_gt->uncore;
1829 	struct drm_i915_private *i915 = uncore->i915;
1830 	int i;
1831 
1832 	/*
1833 	 * General organization
1834 	 * 1. Registers specific to a single generation
1835 	 * 2. Registers which belong to multiple generations
1836 	 * 3. Feature specific registers.
1837 	 * 4. Everything else
1838 	 * Please try to follow the order.
1839 	 */
1840 
1841 	/* 1: Registers specific to a single generation */
1842 	if (IS_VALLEYVIEW(i915))
1843 		gt->forcewake = intel_uncore_read_fw(uncore, FORCEWAKE_VLV);
1844 
1845 	if (GRAPHICS_VER(i915) == 7)
1846 		gt->err_int = intel_uncore_read(uncore, GEN7_ERR_INT);
1847 
1848 	if (GRAPHICS_VER_FULL(i915) >= IP_VER(12, 55)) {
1849 		gt->fault_data0 = intel_gt_mcr_read_any((struct intel_gt *)gt->_gt,
1850 							XEHP_FAULT_TLB_DATA0);
1851 		gt->fault_data1 = intel_gt_mcr_read_any((struct intel_gt *)gt->_gt,
1852 							XEHP_FAULT_TLB_DATA1);
1853 	} else if (GRAPHICS_VER(i915) >= 12) {
1854 		gt->fault_data0 = intel_uncore_read(uncore,
1855 						    GEN12_FAULT_TLB_DATA0);
1856 		gt->fault_data1 = intel_uncore_read(uncore,
1857 						    GEN12_FAULT_TLB_DATA1);
1858 	} else if (GRAPHICS_VER(i915) >= 8) {
1859 		gt->fault_data0 = intel_uncore_read(uncore,
1860 						    GEN8_FAULT_TLB_DATA0);
1861 		gt->fault_data1 = intel_uncore_read(uncore,
1862 						    GEN8_FAULT_TLB_DATA1);
1863 	}
1864 
1865 	if (GRAPHICS_VER(i915) == 6) {
1866 		gt->forcewake = intel_uncore_read_fw(uncore, FORCEWAKE);
1867 		gt->gab_ctl = intel_uncore_read(uncore, GAB_CTL);
1868 		gt->gfx_mode = intel_uncore_read(uncore, GFX_MODE);
1869 	}
1870 
1871 	/* 2: Registers which belong to multiple generations */
1872 	if (GRAPHICS_VER(i915) >= 7)
1873 		gt->forcewake = intel_uncore_read_fw(uncore, FORCEWAKE_MT);
1874 
1875 	if (GRAPHICS_VER(i915) >= 6) {
1876 		if (GRAPHICS_VER(i915) < 12) {
1877 			gt->error = intel_uncore_read(uncore, ERROR_GEN6);
1878 			gt->done_reg = intel_uncore_read(uncore, DONE_REG);
1879 		}
1880 	}
1881 
1882 	/* 3: Feature specific registers */
1883 	if (IS_GRAPHICS_VER(i915, 6, 7)) {
1884 		gt->gam_ecochk = intel_uncore_read(uncore, GAM_ECOCHK);
1885 		gt->gac_eco = intel_uncore_read(uncore, GAC_ECO_BITS);
1886 	}
1887 
1888 	if (IS_GRAPHICS_VER(i915, 8, 11))
1889 		gt->gtt_cache = intel_uncore_read(uncore, HSW_GTT_CACHE_EN);
1890 
1891 	if (GRAPHICS_VER(i915) == 12)
1892 		gt->aux_err = intel_uncore_read(uncore, GEN12_AUX_ERR_DBG);
1893 
1894 	if (GRAPHICS_VER(i915) >= 12) {
1895 		for (i = 0; i < I915_MAX_SFC; i++) {
1896 			/*
1897 			 * SFC_DONE resides in the VD forcewake domain, so it
1898 			 * only exists if the corresponding VCS engine is
1899 			 * present.
1900 			 */
1901 			if ((gt->_gt->info.sfc_mask & BIT(i)) == 0 ||
1902 			    !HAS_ENGINE(gt->_gt, _VCS(i * 2)))
1903 				continue;
1904 
1905 			gt->sfc_done[i] =
1906 				intel_uncore_read(uncore, GEN12_SFC_DONE(i));
1907 		}
1908 
1909 		gt->gam_done = intel_uncore_read(uncore, GEN12_GAM_DONE);
1910 	}
1911 }
1912 
1913 static void gt_record_info(struct intel_gt_coredump *gt)
1914 {
1915 	memcpy(&gt->info, &gt->_gt->info, sizeof(struct intel_gt_info));
1916 	gt->clock_frequency = gt->_gt->clock_frequency;
1917 	gt->clock_period_ns = gt->_gt->clock_period_ns;
1918 }
1919 
1920 /*
1921  * Generate a semi-unique error code. The code is not meant to have meaning, The
1922  * code's only purpose is to try to prevent false duplicated bug reports by
1923  * grossly estimating a GPU error state.
1924  *
1925  * TODO Ideally, hashing the batchbuffer would be a very nice way to determine
1926  * the hang if we could strip the GTT offset information from it.
1927  *
1928  * It's only a small step better than a random number in its current form.
1929  */
1930 static u32 generate_ecode(const struct intel_engine_coredump *ee)
1931 {
1932 	/*
1933 	 * IPEHR would be an ideal way to detect errors, as it's the gross
1934 	 * measure of "the command that hung." However, has some very common
1935 	 * synchronization commands which almost always appear in the case
1936 	 * strictly a client bug. Use instdone to differentiate those some.
1937 	 */
1938 	return ee ? ee->ipehr ^ ee->instdone.instdone : 0;
1939 }
1940 
1941 static const char *error_msg(struct i915_gpu_coredump *error)
1942 {
1943 	struct intel_engine_coredump *first = NULL;
1944 	unsigned int hung_classes = 0;
1945 	struct intel_gt_coredump *gt;
1946 	int len;
1947 
1948 	for (gt = error->gt; gt; gt = gt->next) {
1949 		struct intel_engine_coredump *cs;
1950 
1951 		for (cs = gt->engine; cs; cs = cs->next) {
1952 			if (cs->hung) {
1953 				hung_classes |= BIT(cs->engine->uabi_class);
1954 				if (!first)
1955 					first = cs;
1956 			}
1957 		}
1958 	}
1959 
1960 	len = scnprintf(error->error_msg, sizeof(error->error_msg),
1961 			"GPU HANG: ecode %d:%x:%08x",
1962 			GRAPHICS_VER(error->i915), hung_classes,
1963 			generate_ecode(first));
1964 	if (first && first->context.pid) {
1965 		/* Just show the first executing process, more is confusing */
1966 		len += scnprintf(error->error_msg + len,
1967 				 sizeof(error->error_msg) - len,
1968 				 ", in %s [%d]",
1969 				 first->context.comm, first->context.pid);
1970 	}
1971 
1972 	return error->error_msg;
1973 }
1974 
1975 static void capture_gen(struct i915_gpu_coredump *error)
1976 {
1977 	struct drm_i915_private *i915 = error->i915;
1978 
1979 	error->wakelock = atomic_read(&i915->runtime_pm.wakeref_count);
1980 	error->suspended = pm_runtime_suspended(i915->drm.dev);
1981 
1982 	error->iommu = i915_vtd_active(i915);
1983 	error->reset_count = i915_reset_count(&i915->gpu_error);
1984 	error->suspend_count = i915->suspend_count;
1985 
1986 	i915_params_copy(&error->params, &i915->params);
1987 	memcpy(&error->device_info,
1988 	       INTEL_INFO(i915),
1989 	       sizeof(error->device_info));
1990 	memcpy(&error->runtime_info,
1991 	       RUNTIME_INFO(i915),
1992 	       sizeof(error->runtime_info));
1993 	error->driver_caps = i915->caps;
1994 }
1995 
1996 struct i915_gpu_coredump *
1997 i915_gpu_coredump_alloc(struct drm_i915_private *i915, gfp_t gfp)
1998 {
1999 	struct i915_gpu_coredump *error;
2000 
2001 	if (!i915->params.error_capture)
2002 		return NULL;
2003 
2004 	error = kzalloc(sizeof(*error), gfp);
2005 	if (!error)
2006 		return NULL;
2007 
2008 	kref_init(&error->ref);
2009 	error->i915 = i915;
2010 
2011 	error->time = ktime_get_real();
2012 	error->boottime = ktime_get_boottime();
2013 	error->uptime = ktime_sub(ktime_get(), to_gt(i915)->last_init_time);
2014 	error->capture = jiffies;
2015 
2016 	capture_gen(error);
2017 
2018 	return error;
2019 }
2020 
2021 #define DAY_AS_SECONDS(x) (24 * 60 * 60 * (x))
2022 
2023 struct intel_gt_coredump *
2024 intel_gt_coredump_alloc(struct intel_gt *gt, gfp_t gfp, u32 dump_flags)
2025 {
2026 	struct intel_gt_coredump *gc;
2027 
2028 	gc = kzalloc(sizeof(*gc), gfp);
2029 	if (!gc)
2030 		return NULL;
2031 
2032 	gc->_gt = gt;
2033 	gc->awake = intel_gt_pm_is_awake(gt);
2034 
2035 	gt_record_display_regs(gc);
2036 	gt_record_global_nonguc_regs(gc);
2037 
2038 	/*
2039 	 * GuC dumps global, eng-class and eng-instance registers
2040 	 * (that can change as part of engine state during execution)
2041 	 * before an engine is reset due to a hung context.
2042 	 * GuC captures and reports all three groups of registers
2043 	 * together as a single set before the engine is reset.
2044 	 * Thus, if GuC triggered the context reset we retrieve
2045 	 * the register values as part of gt_record_engines.
2046 	 */
2047 	if (!(dump_flags & CORE_DUMP_FLAG_IS_GUC_CAPTURE))
2048 		gt_record_global_regs(gc);
2049 
2050 	gt_record_fences(gc);
2051 
2052 	return gc;
2053 }
2054 
2055 struct i915_vma_compress *
2056 i915_vma_capture_prepare(struct intel_gt_coredump *gt)
2057 {
2058 	struct i915_vma_compress *compress;
2059 
2060 	compress = kmalloc(sizeof(*compress), ALLOW_FAIL);
2061 	if (!compress)
2062 		return NULL;
2063 
2064 	if (!compress_init(compress)) {
2065 		kfree(compress);
2066 		return NULL;
2067 	}
2068 
2069 	return compress;
2070 }
2071 
2072 void i915_vma_capture_finish(struct intel_gt_coredump *gt,
2073 			     struct i915_vma_compress *compress)
2074 {
2075 	if (!compress)
2076 		return;
2077 
2078 	compress_fini(compress);
2079 	kfree(compress);
2080 }
2081 
2082 static struct i915_gpu_coredump *
2083 __i915_gpu_coredump(struct intel_gt *gt, intel_engine_mask_t engine_mask, u32 dump_flags)
2084 {
2085 	struct drm_i915_private *i915 = gt->i915;
2086 	struct intel_display *display = &i915->display;
2087 	struct i915_gpu_coredump *error;
2088 
2089 	/* Check if GPU capture has been disabled */
2090 	error = READ_ONCE(i915->gpu_error.first_error);
2091 	if (IS_ERR(error))
2092 		return error;
2093 
2094 	error = i915_gpu_coredump_alloc(i915, ALLOW_FAIL);
2095 	if (!error)
2096 		return ERR_PTR(-ENOMEM);
2097 
2098 	error->gt = intel_gt_coredump_alloc(gt, ALLOW_FAIL, dump_flags);
2099 	if (error->gt) {
2100 		struct i915_vma_compress *compress;
2101 
2102 		compress = i915_vma_capture_prepare(error->gt);
2103 		if (!compress) {
2104 			kfree(error->gt);
2105 			kfree(error);
2106 			return ERR_PTR(-ENOMEM);
2107 		}
2108 
2109 		if (INTEL_INFO(i915)->has_gt_uc) {
2110 			error->gt->uc = gt_record_uc(error->gt, compress);
2111 			if (error->gt->uc) {
2112 				if (dump_flags & CORE_DUMP_FLAG_IS_GUC_CAPTURE)
2113 					error->gt->uc->guc.is_guc_capture = true;
2114 				else
2115 					GEM_BUG_ON(error->gt->uc->guc.is_guc_capture);
2116 			}
2117 		}
2118 
2119 		gt_record_info(error->gt);
2120 		gt_record_engines(error->gt, engine_mask, compress, dump_flags);
2121 
2122 
2123 		i915_vma_capture_finish(error->gt, compress);
2124 
2125 		error->simulated |= error->gt->simulated;
2126 	}
2127 
2128 	error->display_snapshot = intel_display_snapshot_capture(display);
2129 
2130 	return error;
2131 }
2132 
2133 static struct i915_gpu_coredump *
2134 i915_gpu_coredump(struct intel_gt *gt, intel_engine_mask_t engine_mask, u32 dump_flags)
2135 {
2136 	static DEFINE_MUTEX(capture_mutex);
2137 	int ret = mutex_lock_interruptible(&capture_mutex);
2138 	struct i915_gpu_coredump *dump;
2139 
2140 	if (ret)
2141 		return ERR_PTR(ret);
2142 
2143 	dump = __i915_gpu_coredump(gt, engine_mask, dump_flags);
2144 	mutex_unlock(&capture_mutex);
2145 
2146 	return dump;
2147 }
2148 
2149 void i915_error_state_store(struct i915_gpu_coredump *error)
2150 {
2151 	struct drm_i915_private *i915;
2152 	static bool warned;
2153 
2154 	if (IS_ERR_OR_NULL(error))
2155 		return;
2156 
2157 	i915 = error->i915;
2158 	drm_info(&i915->drm, "%s\n", error_msg(error));
2159 
2160 	if (error->simulated ||
2161 	    cmpxchg(&i915->gpu_error.first_error, NULL, error))
2162 		return;
2163 
2164 	i915_gpu_coredump_get(error);
2165 
2166 	if (!xchg(&warned, true) &&
2167 	    ktime_get_real_seconds() - DRIVER_TIMESTAMP < DAY_AS_SECONDS(180)) {
2168 		pr_info("GPU hangs can indicate a bug anywhere in the entire gfx stack, including userspace.\n");
2169 		pr_info("Please file a _new_ bug report at https://gitlab.freedesktop.org/drm/intel/issues/new.\n");
2170 		pr_info("Please see https://drm.pages.freedesktop.org/intel-docs/how-to-file-i915-bugs.html for details.\n");
2171 		pr_info("drm/i915 developers can then reassign to the right component if it's not a kernel issue.\n");
2172 		pr_info("The GPU crash dump is required to analyze GPU hangs, so please always attach it.\n");
2173 		pr_info("GPU crash dump saved to /sys/class/drm/card%d/error\n",
2174 			i915->drm.primary->index);
2175 	}
2176 }
2177 
2178 /**
2179  * i915_capture_error_state - capture an error record for later analysis
2180  * @gt: intel_gt which originated the hang
2181  * @engine_mask: hung engines
2182  * @dump_flags: dump flags
2183  *
2184  * Should be called when an error is detected (either a hang or an error
2185  * interrupt) to capture error state from the time of the error.  Fills
2186  * out a structure which becomes available in debugfs for user level tools
2187  * to pick up.
2188  */
2189 void i915_capture_error_state(struct intel_gt *gt,
2190 			      intel_engine_mask_t engine_mask, u32 dump_flags)
2191 {
2192 	struct i915_gpu_coredump *error;
2193 
2194 	error = i915_gpu_coredump(gt, engine_mask, dump_flags);
2195 	if (IS_ERR(error)) {
2196 		cmpxchg(&gt->i915->gpu_error.first_error, NULL, error);
2197 		return;
2198 	}
2199 
2200 	i915_error_state_store(error);
2201 	i915_gpu_coredump_put(error);
2202 }
2203 
2204 static struct i915_gpu_coredump *
2205 i915_first_error_state(struct drm_i915_private *i915)
2206 {
2207 	struct i915_gpu_coredump *error;
2208 
2209 	spin_lock_irq(&i915->gpu_error.lock);
2210 	error = i915->gpu_error.first_error;
2211 	if (!IS_ERR_OR_NULL(error))
2212 		i915_gpu_coredump_get(error);
2213 	spin_unlock_irq(&i915->gpu_error.lock);
2214 
2215 	return error;
2216 }
2217 
2218 void i915_reset_error_state(struct drm_i915_private *i915)
2219 {
2220 	struct i915_gpu_coredump *error;
2221 
2222 	spin_lock_irq(&i915->gpu_error.lock);
2223 	error = i915->gpu_error.first_error;
2224 	if (error != ERR_PTR(-ENODEV)) /* if disabled, always disabled */
2225 		i915->gpu_error.first_error = NULL;
2226 	spin_unlock_irq(&i915->gpu_error.lock);
2227 
2228 	if (!IS_ERR_OR_NULL(error))
2229 		i915_gpu_coredump_put(error);
2230 }
2231 
2232 void i915_disable_error_state(struct drm_i915_private *i915, int err)
2233 {
2234 	spin_lock_irq(&i915->gpu_error.lock);
2235 	if (!i915->gpu_error.first_error)
2236 		i915->gpu_error.first_error = ERR_PTR(err);
2237 	spin_unlock_irq(&i915->gpu_error.lock);
2238 }
2239 
2240 #if IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM)
2241 void intel_klog_error_capture(struct intel_gt *gt,
2242 			      intel_engine_mask_t engine_mask)
2243 {
2244 	static int g_count;
2245 	struct drm_i915_private *i915 = gt->i915;
2246 	struct i915_gpu_coredump *error;
2247 	intel_wakeref_t wakeref;
2248 	size_t buf_size = PAGE_SIZE * 128;
2249 	size_t pos_err;
2250 	char *buf, *ptr, *next;
2251 	int l_count = g_count++;
2252 	int line = 0;
2253 
2254 	/* Can't allocate memory during a reset */
2255 	if (test_bit(I915_RESET_BACKOFF, &gt->reset.flags)) {
2256 		drm_err(&gt->i915->drm, "[Capture/%d.%d] Inside GT reset, skipping error capture :(\n",
2257 			l_count, line++);
2258 		return;
2259 	}
2260 
2261 	error = READ_ONCE(i915->gpu_error.first_error);
2262 	if (error) {
2263 		drm_err(&i915->drm, "[Capture/%d.%d] Clearing existing error capture first...\n",
2264 			l_count, line++);
2265 		i915_reset_error_state(i915);
2266 	}
2267 
2268 	with_intel_runtime_pm(&i915->runtime_pm, wakeref)
2269 		error = i915_gpu_coredump(gt, engine_mask, CORE_DUMP_FLAG_NONE);
2270 
2271 	if (IS_ERR(error)) {
2272 		drm_err(&i915->drm, "[Capture/%d.%d] Failed to capture error capture: %ld!\n",
2273 			l_count, line++, PTR_ERR(error));
2274 		return;
2275 	}
2276 
2277 	buf = kvmalloc(buf_size, GFP_KERNEL);
2278 	if (!buf) {
2279 		drm_err(&i915->drm, "[Capture/%d.%d] Failed to allocate buffer for error capture!\n",
2280 			l_count, line++);
2281 		i915_gpu_coredump_put(error);
2282 		return;
2283 	}
2284 
2285 	drm_info(&i915->drm, "[Capture/%d.%d] Dumping i915 error capture for %ps...\n",
2286 		 l_count, line++, __builtin_return_address(0));
2287 
2288 	/* Largest string length safe to print via dmesg */
2289 #	define MAX_CHUNK	800
2290 
2291 	pos_err = 0;
2292 	while (1) {
2293 		ssize_t got = i915_gpu_coredump_copy_to_buffer(error, buf, pos_err, buf_size - 1);
2294 
2295 		if (got <= 0)
2296 			break;
2297 
2298 		buf[got] = 0;
2299 		pos_err += got;
2300 
2301 		ptr = buf;
2302 		while (got > 0) {
2303 			size_t count;
2304 			char tag[2];
2305 
2306 			next = strnchr(ptr, got, '\n');
2307 			if (next) {
2308 				count = next - ptr;
2309 				*next = 0;
2310 				tag[0] = '>';
2311 				tag[1] = '<';
2312 			} else {
2313 				count = got;
2314 				tag[0] = '}';
2315 				tag[1] = '{';
2316 			}
2317 
2318 			if (count > MAX_CHUNK) {
2319 				size_t pos;
2320 				char *ptr2 = ptr;
2321 
2322 				for (pos = MAX_CHUNK; pos < count; pos += MAX_CHUNK) {
2323 					char chr = ptr[pos];
2324 
2325 					ptr[pos] = 0;
2326 					drm_info(&i915->drm, "[Capture/%d.%d] }%s{\n",
2327 						 l_count, line++, ptr2);
2328 					ptr[pos] = chr;
2329 					ptr2 = ptr + pos;
2330 
2331 					/*
2332 					 * If spewing large amounts of data via a serial console,
2333 					 * this can be a very slow process. So be friendly and try
2334 					 * not to cause 'softlockup on CPU' problems.
2335 					 */
2336 					cond_resched();
2337 				}
2338 
2339 				if (ptr2 < (ptr + count))
2340 					drm_info(&i915->drm, "[Capture/%d.%d] %c%s%c\n",
2341 						 l_count, line++, tag[0], ptr2, tag[1]);
2342 				else if (tag[0] == '>')
2343 					drm_info(&i915->drm, "[Capture/%d.%d] ><\n",
2344 						 l_count, line++);
2345 			} else {
2346 				drm_info(&i915->drm, "[Capture/%d.%d] %c%s%c\n",
2347 					 l_count, line++, tag[0], ptr, tag[1]);
2348 			}
2349 
2350 			ptr = next;
2351 			got -= count;
2352 			if (next) {
2353 				ptr++;
2354 				got--;
2355 			}
2356 
2357 			/* As above. */
2358 			cond_resched();
2359 		}
2360 
2361 		if (got)
2362 			drm_info(&i915->drm, "[Capture/%d.%d] Got %zd bytes remaining!\n",
2363 				 l_count, line++, got);
2364 	}
2365 
2366 	kvfree(buf);
2367 
2368 	drm_info(&i915->drm, "[Capture/%d.%d] Dumped %zd bytes\n", l_count, line++, pos_err);
2369 }
2370 #endif
2371 
2372 static ssize_t gpu_state_read(struct file *file, char __user *ubuf,
2373 			      size_t count, loff_t *pos)
2374 {
2375 	struct i915_gpu_coredump *error;
2376 	ssize_t ret;
2377 	void *buf;
2378 
2379 	error = file->private_data;
2380 	if (!error)
2381 		return 0;
2382 
2383 	/* Bounce buffer required because of kernfs __user API convenience. */
2384 	buf = kmalloc(count, GFP_KERNEL);
2385 	if (!buf)
2386 		return -ENOMEM;
2387 
2388 	ret = i915_gpu_coredump_copy_to_buffer(error, buf, *pos, count);
2389 	if (ret <= 0)
2390 		goto out;
2391 
2392 	if (!copy_to_user(ubuf, buf, ret))
2393 		*pos += ret;
2394 	else
2395 		ret = -EFAULT;
2396 
2397 out:
2398 	kfree(buf);
2399 	return ret;
2400 }
2401 
2402 static int gpu_state_release(struct inode *inode, struct file *file)
2403 {
2404 	i915_gpu_coredump_put(file->private_data);
2405 	return 0;
2406 }
2407 
2408 static int i915_gpu_info_open(struct inode *inode, struct file *file)
2409 {
2410 	struct drm_i915_private *i915 = inode->i_private;
2411 	struct i915_gpu_coredump *gpu;
2412 	intel_wakeref_t wakeref;
2413 
2414 	gpu = NULL;
2415 	with_intel_runtime_pm(&i915->runtime_pm, wakeref)
2416 		gpu = i915_gpu_coredump(to_gt(i915), ALL_ENGINES, CORE_DUMP_FLAG_NONE);
2417 
2418 	if (IS_ERR(gpu))
2419 		return PTR_ERR(gpu);
2420 
2421 	file->private_data = gpu;
2422 	return 0;
2423 }
2424 
2425 static const struct file_operations i915_gpu_info_fops = {
2426 	.owner = THIS_MODULE,
2427 	.open = i915_gpu_info_open,
2428 	.read = gpu_state_read,
2429 	.llseek = default_llseek,
2430 	.release = gpu_state_release,
2431 };
2432 
2433 static ssize_t
2434 i915_error_state_write(struct file *filp,
2435 		       const char __user *ubuf,
2436 		       size_t cnt,
2437 		       loff_t *ppos)
2438 {
2439 	struct i915_gpu_coredump *error = filp->private_data;
2440 
2441 	if (!error)
2442 		return 0;
2443 
2444 	drm_dbg(&error->i915->drm, "Resetting error state\n");
2445 	i915_reset_error_state(error->i915);
2446 
2447 	return cnt;
2448 }
2449 
2450 static int i915_error_state_open(struct inode *inode, struct file *file)
2451 {
2452 	struct i915_gpu_coredump *error;
2453 
2454 	error = i915_first_error_state(inode->i_private);
2455 	if (IS_ERR(error))
2456 		return PTR_ERR(error);
2457 
2458 	file->private_data  = error;
2459 	return 0;
2460 }
2461 
2462 static const struct file_operations i915_error_state_fops = {
2463 	.owner = THIS_MODULE,
2464 	.open = i915_error_state_open,
2465 	.read = gpu_state_read,
2466 	.write = i915_error_state_write,
2467 	.llseek = default_llseek,
2468 	.release = gpu_state_release,
2469 };
2470 
2471 void i915_gpu_error_debugfs_register(struct drm_i915_private *i915)
2472 {
2473 	struct drm_minor *minor = i915->drm.primary;
2474 
2475 	debugfs_create_file("i915_error_state", 0644, minor->debugfs_root, i915,
2476 			    &i915_error_state_fops);
2477 	debugfs_create_file("i915_gpu_info", 0644, minor->debugfs_root, i915,
2478 			    &i915_gpu_info_fops);
2479 }
2480 
2481 static ssize_t error_state_read(struct file *filp, struct kobject *kobj,
2482 				struct bin_attribute *attr, char *buf,
2483 				loff_t off, size_t count)
2484 {
2485 
2486 	struct device *kdev = kobj_to_dev(kobj);
2487 	struct drm_i915_private *i915 = kdev_minor_to_i915(kdev);
2488 	struct i915_gpu_coredump *gpu;
2489 	ssize_t ret = 0;
2490 
2491 	/*
2492 	 * FIXME: Concurrent clients triggering resets and reading + clearing
2493 	 * dumps can cause inconsistent sysfs reads when a user calls in with a
2494 	 * non-zero offset to complete a prior partial read but the
2495 	 * gpu_coredump has been cleared or replaced.
2496 	 */
2497 
2498 	gpu = i915_first_error_state(i915);
2499 	if (IS_ERR(gpu)) {
2500 		ret = PTR_ERR(gpu);
2501 	} else if (gpu) {
2502 		ret = i915_gpu_coredump_copy_to_buffer(gpu, buf, off, count);
2503 		i915_gpu_coredump_put(gpu);
2504 	} else {
2505 		const char *str = "No error state collected\n";
2506 		size_t len = strlen(str);
2507 
2508 		if (off < len) {
2509 			ret = min_t(size_t, count, len - off);
2510 			memcpy(buf, str + off, ret);
2511 		}
2512 	}
2513 
2514 	return ret;
2515 }
2516 
2517 static ssize_t error_state_write(struct file *file, struct kobject *kobj,
2518 				 struct bin_attribute *attr, char *buf,
2519 				 loff_t off, size_t count)
2520 {
2521 	struct device *kdev = kobj_to_dev(kobj);
2522 	struct drm_i915_private *dev_priv = kdev_minor_to_i915(kdev);
2523 
2524 	drm_dbg(&dev_priv->drm, "Resetting error state\n");
2525 	i915_reset_error_state(dev_priv);
2526 
2527 	return count;
2528 }
2529 
2530 static const struct bin_attribute error_state_attr = {
2531 	.attr.name = "error",
2532 	.attr.mode = S_IRUSR | S_IWUSR,
2533 	.size = 0,
2534 	.read = error_state_read,
2535 	.write = error_state_write,
2536 };
2537 
2538 void i915_gpu_error_sysfs_setup(struct drm_i915_private *i915)
2539 {
2540 	struct device *kdev = i915->drm.primary->kdev;
2541 
2542 	if (sysfs_create_bin_file(&kdev->kobj, &error_state_attr))
2543 		drm_err(&i915->drm, "error_state sysfs setup failed\n");
2544 }
2545 
2546 void i915_gpu_error_sysfs_teardown(struct drm_i915_private *i915)
2547 {
2548 	struct device *kdev = i915->drm.primary->kdev;
2549 
2550 	sysfs_remove_bin_file(&kdev->kobj, &error_state_attr);
2551 }
2552