xref: /openbmc/linux/drivers/gpu/drm/i915/gt/intel_gt.c (revision 15e3ae36)
1 // SPDX-License-Identifier: MIT
2 /*
3  * Copyright © 2019 Intel Corporation
4  */
5 
6 #include "debugfs_gt.h"
7 #include "i915_drv.h"
8 #include "intel_context.h"
9 #include "intel_gt.h"
10 #include "intel_gt_pm.h"
11 #include "intel_gt_requests.h"
12 #include "intel_mocs.h"
13 #include "intel_rc6.h"
14 #include "intel_renderstate.h"
15 #include "intel_rps.h"
16 #include "intel_uncore.h"
17 #include "intel_pm.h"
18 
19 void intel_gt_init_early(struct intel_gt *gt, struct drm_i915_private *i915)
20 {
21 	gt->i915 = i915;
22 	gt->uncore = &i915->uncore;
23 
24 	spin_lock_init(&gt->irq_lock);
25 
26 	INIT_LIST_HEAD(&gt->closed_vma);
27 	spin_lock_init(&gt->closed_lock);
28 
29 	intel_gt_init_reset(gt);
30 	intel_gt_init_requests(gt);
31 	intel_gt_init_timelines(gt);
32 	intel_gt_pm_init_early(gt);
33 
34 	intel_rps_init_early(&gt->rps);
35 	intel_uc_init_early(&gt->uc);
36 }
37 
38 void intel_gt_init_hw_early(struct intel_gt *gt, struct i915_ggtt *ggtt)
39 {
40 	gt->ggtt = ggtt;
41 }
42 
43 static void init_unused_ring(struct intel_gt *gt, u32 base)
44 {
45 	struct intel_uncore *uncore = gt->uncore;
46 
47 	intel_uncore_write(uncore, RING_CTL(base), 0);
48 	intel_uncore_write(uncore, RING_HEAD(base), 0);
49 	intel_uncore_write(uncore, RING_TAIL(base), 0);
50 	intel_uncore_write(uncore, RING_START(base), 0);
51 }
52 
53 static void init_unused_rings(struct intel_gt *gt)
54 {
55 	struct drm_i915_private *i915 = gt->i915;
56 
57 	if (IS_I830(i915)) {
58 		init_unused_ring(gt, PRB1_BASE);
59 		init_unused_ring(gt, SRB0_BASE);
60 		init_unused_ring(gt, SRB1_BASE);
61 		init_unused_ring(gt, SRB2_BASE);
62 		init_unused_ring(gt, SRB3_BASE);
63 	} else if (IS_GEN(i915, 2)) {
64 		init_unused_ring(gt, SRB0_BASE);
65 		init_unused_ring(gt, SRB1_BASE);
66 	} else if (IS_GEN(i915, 3)) {
67 		init_unused_ring(gt, PRB1_BASE);
68 		init_unused_ring(gt, PRB2_BASE);
69 	}
70 }
71 
72 int intel_gt_init_hw(struct intel_gt *gt)
73 {
74 	struct drm_i915_private *i915 = gt->i915;
75 	struct intel_uncore *uncore = gt->uncore;
76 	int ret;
77 
78 	gt->last_init_time = ktime_get();
79 
80 	/* Double layer security blanket, see i915_gem_init() */
81 	intel_uncore_forcewake_get(uncore, FORCEWAKE_ALL);
82 
83 	if (HAS_EDRAM(i915) && INTEL_GEN(i915) < 9)
84 		intel_uncore_rmw(uncore, HSW_IDICR, 0, IDIHASHMSK(0xf));
85 
86 	if (IS_HASWELL(i915))
87 		intel_uncore_write(uncore,
88 				   MI_PREDICATE_RESULT_2,
89 				   IS_HSW_GT3(i915) ?
90 				   LOWER_SLICE_ENABLED : LOWER_SLICE_DISABLED);
91 
92 	/* Apply the GT workarounds... */
93 	intel_gt_apply_workarounds(gt);
94 	/* ...and determine whether they are sticking. */
95 	intel_gt_verify_workarounds(gt, "init");
96 
97 	intel_gt_init_swizzling(gt);
98 
99 	/*
100 	 * At least 830 can leave some of the unused rings
101 	 * "active" (ie. head != tail) after resume which
102 	 * will prevent c3 entry. Makes sure all unused rings
103 	 * are totally idle.
104 	 */
105 	init_unused_rings(gt);
106 
107 	ret = i915_ppgtt_init_hw(gt);
108 	if (ret) {
109 		DRM_ERROR("Enabling PPGTT failed (%d)\n", ret);
110 		goto out;
111 	}
112 
113 	/* We can't enable contexts until all firmware is loaded */
114 	ret = intel_uc_init_hw(&gt->uc);
115 	if (ret) {
116 		i915_probe_error(i915, "Enabling uc failed (%d)\n", ret);
117 		goto out;
118 	}
119 
120 	intel_mocs_init(gt);
121 
122 out:
123 	intel_uncore_forcewake_put(uncore, FORCEWAKE_ALL);
124 	return ret;
125 }
126 
127 static void rmw_set(struct intel_uncore *uncore, i915_reg_t reg, u32 set)
128 {
129 	intel_uncore_rmw(uncore, reg, 0, set);
130 }
131 
132 static void rmw_clear(struct intel_uncore *uncore, i915_reg_t reg, u32 clr)
133 {
134 	intel_uncore_rmw(uncore, reg, clr, 0);
135 }
136 
137 static void clear_register(struct intel_uncore *uncore, i915_reg_t reg)
138 {
139 	intel_uncore_rmw(uncore, reg, 0, 0);
140 }
141 
142 static void gen8_clear_engine_error_register(struct intel_engine_cs *engine)
143 {
144 	GEN6_RING_FAULT_REG_RMW(engine, RING_FAULT_VALID, 0);
145 	GEN6_RING_FAULT_REG_POSTING_READ(engine);
146 }
147 
148 void
149 intel_gt_clear_error_registers(struct intel_gt *gt,
150 			       intel_engine_mask_t engine_mask)
151 {
152 	struct drm_i915_private *i915 = gt->i915;
153 	struct intel_uncore *uncore = gt->uncore;
154 	u32 eir;
155 
156 	if (!IS_GEN(i915, 2))
157 		clear_register(uncore, PGTBL_ER);
158 
159 	if (INTEL_GEN(i915) < 4)
160 		clear_register(uncore, IPEIR(RENDER_RING_BASE));
161 	else
162 		clear_register(uncore, IPEIR_I965);
163 
164 	clear_register(uncore, EIR);
165 	eir = intel_uncore_read(uncore, EIR);
166 	if (eir) {
167 		/*
168 		 * some errors might have become stuck,
169 		 * mask them.
170 		 */
171 		DRM_DEBUG_DRIVER("EIR stuck: 0x%08x, masking\n", eir);
172 		rmw_set(uncore, EMR, eir);
173 		intel_uncore_write(uncore, GEN2_IIR,
174 				   I915_MASTER_ERROR_INTERRUPT);
175 	}
176 
177 	if (INTEL_GEN(i915) >= 12) {
178 		rmw_clear(uncore, GEN12_RING_FAULT_REG, RING_FAULT_VALID);
179 		intel_uncore_posting_read(uncore, GEN12_RING_FAULT_REG);
180 	} else if (INTEL_GEN(i915) >= 8) {
181 		rmw_clear(uncore, GEN8_RING_FAULT_REG, RING_FAULT_VALID);
182 		intel_uncore_posting_read(uncore, GEN8_RING_FAULT_REG);
183 	} else if (INTEL_GEN(i915) >= 6) {
184 		struct intel_engine_cs *engine;
185 		enum intel_engine_id id;
186 
187 		for_each_engine_masked(engine, gt, engine_mask, id)
188 			gen8_clear_engine_error_register(engine);
189 	}
190 }
191 
192 static void gen6_check_faults(struct intel_gt *gt)
193 {
194 	struct intel_engine_cs *engine;
195 	enum intel_engine_id id;
196 	u32 fault;
197 
198 	for_each_engine(engine, gt, id) {
199 		fault = GEN6_RING_FAULT_REG_READ(engine);
200 		if (fault & RING_FAULT_VALID) {
201 			drm_dbg(&engine->i915->drm, "Unexpected fault\n"
202 				"\tAddr: 0x%08lx\n"
203 				"\tAddress space: %s\n"
204 				"\tSource ID: %d\n"
205 				"\tType: %d\n",
206 				fault & PAGE_MASK,
207 				fault & RING_FAULT_GTTSEL_MASK ?
208 				"GGTT" : "PPGTT",
209 				RING_FAULT_SRCID(fault),
210 				RING_FAULT_FAULT_TYPE(fault));
211 		}
212 	}
213 }
214 
215 static void gen8_check_faults(struct intel_gt *gt)
216 {
217 	struct intel_uncore *uncore = gt->uncore;
218 	i915_reg_t fault_reg, fault_data0_reg, fault_data1_reg;
219 	u32 fault;
220 
221 	if (INTEL_GEN(gt->i915) >= 12) {
222 		fault_reg = GEN12_RING_FAULT_REG;
223 		fault_data0_reg = GEN12_FAULT_TLB_DATA0;
224 		fault_data1_reg = GEN12_FAULT_TLB_DATA1;
225 	} else {
226 		fault_reg = GEN8_RING_FAULT_REG;
227 		fault_data0_reg = GEN8_FAULT_TLB_DATA0;
228 		fault_data1_reg = GEN8_FAULT_TLB_DATA1;
229 	}
230 
231 	fault = intel_uncore_read(uncore, fault_reg);
232 	if (fault & RING_FAULT_VALID) {
233 		u32 fault_data0, fault_data1;
234 		u64 fault_addr;
235 
236 		fault_data0 = intel_uncore_read(uncore, fault_data0_reg);
237 		fault_data1 = intel_uncore_read(uncore, fault_data1_reg);
238 
239 		fault_addr = ((u64)(fault_data1 & FAULT_VA_HIGH_BITS) << 44) |
240 			     ((u64)fault_data0 << 12);
241 
242 		drm_dbg(&uncore->i915->drm, "Unexpected fault\n"
243 			"\tAddr: 0x%08x_%08x\n"
244 			"\tAddress space: %s\n"
245 			"\tEngine ID: %d\n"
246 			"\tSource ID: %d\n"
247 			"\tType: %d\n",
248 			upper_32_bits(fault_addr), lower_32_bits(fault_addr),
249 			fault_data1 & FAULT_GTT_SEL ? "GGTT" : "PPGTT",
250 			GEN8_RING_FAULT_ENGINE_ID(fault),
251 			RING_FAULT_SRCID(fault),
252 			RING_FAULT_FAULT_TYPE(fault));
253 	}
254 }
255 
256 void intel_gt_check_and_clear_faults(struct intel_gt *gt)
257 {
258 	struct drm_i915_private *i915 = gt->i915;
259 
260 	/* From GEN8 onwards we only have one 'All Engine Fault Register' */
261 	if (INTEL_GEN(i915) >= 8)
262 		gen8_check_faults(gt);
263 	else if (INTEL_GEN(i915) >= 6)
264 		gen6_check_faults(gt);
265 	else
266 		return;
267 
268 	intel_gt_clear_error_registers(gt, ALL_ENGINES);
269 }
270 
271 void intel_gt_flush_ggtt_writes(struct intel_gt *gt)
272 {
273 	struct intel_uncore *uncore = gt->uncore;
274 	intel_wakeref_t wakeref;
275 
276 	/*
277 	 * No actual flushing is required for the GTT write domain for reads
278 	 * from the GTT domain. Writes to it "immediately" go to main memory
279 	 * as far as we know, so there's no chipset flush. It also doesn't
280 	 * land in the GPU render cache.
281 	 *
282 	 * However, we do have to enforce the order so that all writes through
283 	 * the GTT land before any writes to the device, such as updates to
284 	 * the GATT itself.
285 	 *
286 	 * We also have to wait a bit for the writes to land from the GTT.
287 	 * An uncached read (i.e. mmio) seems to be ideal for the round-trip
288 	 * timing. This issue has only been observed when switching quickly
289 	 * between GTT writes and CPU reads from inside the kernel on recent hw,
290 	 * and it appears to only affect discrete GTT blocks (i.e. on LLC
291 	 * system agents we cannot reproduce this behaviour, until Cannonlake
292 	 * that was!).
293 	 */
294 
295 	wmb();
296 
297 	if (INTEL_INFO(gt->i915)->has_coherent_ggtt)
298 		return;
299 
300 	intel_gt_chipset_flush(gt);
301 
302 	with_intel_runtime_pm_if_in_use(uncore->rpm, wakeref) {
303 		unsigned long flags;
304 
305 		spin_lock_irqsave(&uncore->lock, flags);
306 		intel_uncore_posting_read_fw(uncore,
307 					     RING_HEAD(RENDER_RING_BASE));
308 		spin_unlock_irqrestore(&uncore->lock, flags);
309 	}
310 }
311 
312 void intel_gt_chipset_flush(struct intel_gt *gt)
313 {
314 	wmb();
315 	if (INTEL_GEN(gt->i915) < 6)
316 		intel_gtt_chipset_flush();
317 }
318 
319 void intel_gt_driver_register(struct intel_gt *gt)
320 {
321 	intel_rps_driver_register(&gt->rps);
322 
323 	debugfs_gt_register(gt);
324 }
325 
326 static int intel_gt_init_scratch(struct intel_gt *gt, unsigned int size)
327 {
328 	struct drm_i915_private *i915 = gt->i915;
329 	struct drm_i915_gem_object *obj;
330 	struct i915_vma *vma;
331 	int ret;
332 
333 	obj = i915_gem_object_create_stolen(i915, size);
334 	if (IS_ERR(obj))
335 		obj = i915_gem_object_create_internal(i915, size);
336 	if (IS_ERR(obj)) {
337 		DRM_ERROR("Failed to allocate scratch page\n");
338 		return PTR_ERR(obj);
339 	}
340 
341 	vma = i915_vma_instance(obj, &gt->ggtt->vm, NULL);
342 	if (IS_ERR(vma)) {
343 		ret = PTR_ERR(vma);
344 		goto err_unref;
345 	}
346 
347 	ret = i915_ggtt_pin(vma, 0, PIN_HIGH);
348 	if (ret)
349 		goto err_unref;
350 
351 	gt->scratch = i915_vma_make_unshrinkable(vma);
352 
353 	return 0;
354 
355 err_unref:
356 	i915_gem_object_put(obj);
357 	return ret;
358 }
359 
360 static void intel_gt_fini_scratch(struct intel_gt *gt)
361 {
362 	i915_vma_unpin_and_release(&gt->scratch, 0);
363 }
364 
365 static struct i915_address_space *kernel_vm(struct intel_gt *gt)
366 {
367 	if (INTEL_PPGTT(gt->i915) > INTEL_PPGTT_ALIASING)
368 		return &i915_ppgtt_create(gt)->vm;
369 	else
370 		return i915_vm_get(&gt->ggtt->vm);
371 }
372 
373 static int __intel_context_flush_retire(struct intel_context *ce)
374 {
375 	struct intel_timeline *tl;
376 
377 	tl = intel_context_timeline_lock(ce);
378 	if (IS_ERR(tl))
379 		return PTR_ERR(tl);
380 
381 	intel_context_timeline_unlock(tl);
382 	return 0;
383 }
384 
385 static int __engines_record_defaults(struct intel_gt *gt)
386 {
387 	struct i915_request *requests[I915_NUM_ENGINES] = {};
388 	struct intel_engine_cs *engine;
389 	enum intel_engine_id id;
390 	int err = 0;
391 
392 	/*
393 	 * As we reset the gpu during very early sanitisation, the current
394 	 * register state on the GPU should reflect its defaults values.
395 	 * We load a context onto the hw (with restore-inhibit), then switch
396 	 * over to a second context to save that default register state. We
397 	 * can then prime every new context with that state so they all start
398 	 * from the same default HW values.
399 	 */
400 
401 	for_each_engine(engine, gt, id) {
402 		struct intel_renderstate so;
403 		struct intel_context *ce;
404 		struct i915_request *rq;
405 
406 		/* We must be able to switch to something! */
407 		GEM_BUG_ON(!engine->kernel_context);
408 
409 		err = intel_renderstate_init(&so, engine);
410 		if (err)
411 			goto out;
412 
413 		ce = intel_context_create(engine);
414 		if (IS_ERR(ce)) {
415 			err = PTR_ERR(ce);
416 			goto out;
417 		}
418 
419 		rq = intel_context_create_request(ce);
420 		if (IS_ERR(rq)) {
421 			err = PTR_ERR(rq);
422 			intel_context_put(ce);
423 			goto out;
424 		}
425 
426 		err = intel_engine_emit_ctx_wa(rq);
427 		if (err)
428 			goto err_rq;
429 
430 		err = intel_renderstate_emit(&so, rq);
431 		if (err)
432 			goto err_rq;
433 
434 err_rq:
435 		requests[id] = i915_request_get(rq);
436 		i915_request_add(rq);
437 		intel_renderstate_fini(&so);
438 		if (err)
439 			goto out;
440 	}
441 
442 	/* Flush the default context image to memory, and enable powersaving. */
443 	if (intel_gt_wait_for_idle(gt, I915_GEM_IDLE_TIMEOUT) == -ETIME) {
444 		err = -EIO;
445 		goto out;
446 	}
447 
448 	for (id = 0; id < ARRAY_SIZE(requests); id++) {
449 		struct i915_request *rq;
450 		struct i915_vma *state;
451 		void *vaddr;
452 
453 		rq = requests[id];
454 		if (!rq)
455 			continue;
456 
457 		if (rq->fence.error) {
458 			err = -EIO;
459 			goto out;
460 		}
461 
462 		GEM_BUG_ON(!test_bit(CONTEXT_ALLOC_BIT, &rq->context->flags));
463 		state = rq->context->state;
464 		if (!state)
465 			continue;
466 
467 		/* Serialise with retirement on another CPU */
468 		GEM_BUG_ON(!i915_request_completed(rq));
469 		err = __intel_context_flush_retire(rq->context);
470 		if (err)
471 			goto out;
472 
473 		/* We want to be able to unbind the state from the GGTT */
474 		GEM_BUG_ON(intel_context_is_pinned(rq->context));
475 
476 		/*
477 		 * As we will hold a reference to the logical state, it will
478 		 * not be torn down with the context, and importantly the
479 		 * object will hold onto its vma (making it possible for a
480 		 * stray GTT write to corrupt our defaults). Unmap the vma
481 		 * from the GTT to prevent such accidents and reclaim the
482 		 * space.
483 		 */
484 		err = i915_vma_unbind(state);
485 		if (err)
486 			goto out;
487 
488 		i915_gem_object_lock(state->obj);
489 		err = i915_gem_object_set_to_cpu_domain(state->obj, false);
490 		i915_gem_object_unlock(state->obj);
491 		if (err)
492 			goto out;
493 
494 		i915_gem_object_set_cache_coherency(state->obj, I915_CACHE_LLC);
495 
496 		/* Check we can acquire the image of the context state */
497 		vaddr = i915_gem_object_pin_map(state->obj, I915_MAP_FORCE_WB);
498 		if (IS_ERR(vaddr)) {
499 			err = PTR_ERR(vaddr);
500 			goto out;
501 		}
502 
503 		rq->engine->default_state = i915_gem_object_get(state->obj);
504 		i915_gem_object_unpin_map(state->obj);
505 	}
506 
507 out:
508 	/*
509 	 * If we have to abandon now, we expect the engines to be idle
510 	 * and ready to be torn-down. The quickest way we can accomplish
511 	 * this is by declaring ourselves wedged.
512 	 */
513 	if (err)
514 		intel_gt_set_wedged(gt);
515 
516 	for (id = 0; id < ARRAY_SIZE(requests); id++) {
517 		struct intel_context *ce;
518 		struct i915_request *rq;
519 
520 		rq = requests[id];
521 		if (!rq)
522 			continue;
523 
524 		ce = rq->context;
525 		i915_request_put(rq);
526 		intel_context_put(ce);
527 	}
528 	return err;
529 }
530 
531 static int __engines_verify_workarounds(struct intel_gt *gt)
532 {
533 	struct intel_engine_cs *engine;
534 	enum intel_engine_id id;
535 	int err = 0;
536 
537 	if (!IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM))
538 		return 0;
539 
540 	for_each_engine(engine, gt, id) {
541 		if (intel_engine_verify_workarounds(engine, "load"))
542 			err = -EIO;
543 	}
544 
545 	/* Flush and restore the kernel context for safety */
546 	if (intel_gt_wait_for_idle(gt, I915_GEM_IDLE_TIMEOUT) == -ETIME)
547 		err = -EIO;
548 
549 	return err;
550 }
551 
552 static void __intel_gt_disable(struct intel_gt *gt)
553 {
554 	intel_gt_set_wedged_on_init(gt);
555 
556 	intel_gt_suspend_prepare(gt);
557 	intel_gt_suspend_late(gt);
558 
559 	GEM_BUG_ON(intel_gt_pm_is_awake(gt));
560 }
561 
562 int intel_gt_init(struct intel_gt *gt)
563 {
564 	int err;
565 
566 	err = i915_inject_probe_error(gt->i915, -ENODEV);
567 	if (err)
568 		return err;
569 
570 	/*
571 	 * This is just a security blanket to placate dragons.
572 	 * On some systems, we very sporadically observe that the first TLBs
573 	 * used by the CS may be stale, despite us poking the TLB reset. If
574 	 * we hold the forcewake during initialisation these problems
575 	 * just magically go away.
576 	 */
577 	intel_uncore_forcewake_get(gt->uncore, FORCEWAKE_ALL);
578 
579 	err = intel_gt_init_scratch(gt, IS_GEN(gt->i915, 2) ? SZ_256K : SZ_4K);
580 	if (err)
581 		goto out_fw;
582 
583 	intel_gt_pm_init(gt);
584 
585 	gt->vm = kernel_vm(gt);
586 	if (!gt->vm) {
587 		err = -ENOMEM;
588 		goto err_pm;
589 	}
590 
591 	err = intel_engines_init(gt);
592 	if (err)
593 		goto err_engines;
594 
595 	err = intel_uc_init(&gt->uc);
596 	if (err)
597 		goto err_engines;
598 
599 	err = intel_gt_resume(gt);
600 	if (err)
601 		goto err_uc_init;
602 
603 	err = __engines_record_defaults(gt);
604 	if (err)
605 		goto err_gt;
606 
607 	err = __engines_verify_workarounds(gt);
608 	if (err)
609 		goto err_gt;
610 
611 	err = i915_inject_probe_error(gt->i915, -EIO);
612 	if (err)
613 		goto err_gt;
614 
615 	goto out_fw;
616 err_gt:
617 	__intel_gt_disable(gt);
618 	intel_uc_fini_hw(&gt->uc);
619 err_uc_init:
620 	intel_uc_fini(&gt->uc);
621 err_engines:
622 	intel_engines_release(gt);
623 	i915_vm_put(fetch_and_zero(&gt->vm));
624 err_pm:
625 	intel_gt_pm_fini(gt);
626 	intel_gt_fini_scratch(gt);
627 out_fw:
628 	if (err)
629 		intel_gt_set_wedged_on_init(gt);
630 	intel_uncore_forcewake_put(gt->uncore, FORCEWAKE_ALL);
631 	return err;
632 }
633 
634 void intel_gt_driver_remove(struct intel_gt *gt)
635 {
636 	__intel_gt_disable(gt);
637 
638 	intel_uc_fini_hw(&gt->uc);
639 	intel_uc_fini(&gt->uc);
640 
641 	intel_engines_release(gt);
642 }
643 
644 void intel_gt_driver_unregister(struct intel_gt *gt)
645 {
646 	intel_rps_driver_unregister(&gt->rps);
647 
648 	/*
649 	 * Upon unregistering the device to prevent any new users, cancel
650 	 * all in-flight requests so that we can quickly unbind the active
651 	 * resources.
652 	 */
653 	intel_gt_set_wedged(gt);
654 }
655 
656 void intel_gt_driver_release(struct intel_gt *gt)
657 {
658 	struct i915_address_space *vm;
659 
660 	vm = fetch_and_zero(&gt->vm);
661 	if (vm) /* FIXME being called twice on error paths :( */
662 		i915_vm_put(vm);
663 
664 	intel_gt_pm_fini(gt);
665 	intel_gt_fini_scratch(gt);
666 }
667 
668 void intel_gt_driver_late_release(struct intel_gt *gt)
669 {
670 	/* We need to wait for inflight RCU frees to release their grip */
671 	rcu_barrier();
672 
673 	intel_uc_driver_late_release(&gt->uc);
674 	intel_gt_fini_requests(gt);
675 	intel_gt_fini_reset(gt);
676 	intel_gt_fini_timelines(gt);
677 	intel_engines_free(gt);
678 }
679