xref: /openbmc/linux/drivers/gpu/drm/i915/gt/uc/intel_guc.c (revision d58f75de)
1 // SPDX-License-Identifier: MIT
2 /*
3  * Copyright © 2014-2019 Intel Corporation
4  */
5 
6 #include "gt/intel_gt.h"
7 #include "gt/intel_gt_irq.h"
8 #include "gt/intel_gt_pm_irq.h"
9 #include "intel_guc.h"
10 #include "intel_guc_ads.h"
11 #include "intel_guc_submission.h"
12 #include "i915_drv.h"
13 
14 /**
15  * DOC: GuC
16  *
17  * The GuC is a microcontroller inside the GT HW, introduced in gen9. The GuC is
18  * designed to offload some of the functionality usually performed by the host
19  * driver; currently the main operations it can take care of are:
20  *
21  * - Authentication of the HuC, which is required to fully enable HuC usage.
22  * - Low latency graphics context scheduling (a.k.a. GuC submission).
23  * - GT Power management.
24  *
25  * The enable_guc module parameter can be used to select which of those
26  * operations to enable within GuC. Note that not all the operations are
27  * supported on all gen9+ platforms.
28  *
29  * Enabling the GuC is not mandatory and therefore the firmware is only loaded
30  * if at least one of the operations is selected. However, not loading the GuC
31  * might result in the loss of some features that do require the GuC (currently
32  * just the HuC, but more are expected to land in the future).
33  */
34 
35 void intel_guc_notify(struct intel_guc *guc)
36 {
37 	struct intel_gt *gt = guc_to_gt(guc);
38 
39 	/*
40 	 * On Gen11+, the value written to the register is passes as a payload
41 	 * to the FW. However, the FW currently treats all values the same way
42 	 * (H2G interrupt), so we can just write the value that the HW expects
43 	 * on older gens.
44 	 */
45 	intel_uncore_write(gt->uncore, guc->notify_reg, GUC_SEND_TRIGGER);
46 }
47 
48 static inline i915_reg_t guc_send_reg(struct intel_guc *guc, u32 i)
49 {
50 	GEM_BUG_ON(!guc->send_regs.base);
51 	GEM_BUG_ON(!guc->send_regs.count);
52 	GEM_BUG_ON(i >= guc->send_regs.count);
53 
54 	return _MMIO(guc->send_regs.base + 4 * i);
55 }
56 
57 void intel_guc_init_send_regs(struct intel_guc *guc)
58 {
59 	struct intel_gt *gt = guc_to_gt(guc);
60 	enum forcewake_domains fw_domains = 0;
61 	unsigned int i;
62 
63 	if (INTEL_GEN(gt->i915) >= 11) {
64 		guc->send_regs.base =
65 				i915_mmio_reg_offset(GEN11_SOFT_SCRATCH(0));
66 		guc->send_regs.count = GEN11_SOFT_SCRATCH_COUNT;
67 	} else {
68 		guc->send_regs.base = i915_mmio_reg_offset(SOFT_SCRATCH(0));
69 		guc->send_regs.count = GUC_MAX_MMIO_MSG_LEN;
70 		BUILD_BUG_ON(GUC_MAX_MMIO_MSG_LEN > SOFT_SCRATCH_COUNT);
71 	}
72 
73 	for (i = 0; i < guc->send_regs.count; i++) {
74 		fw_domains |= intel_uncore_forcewake_for_reg(gt->uncore,
75 					guc_send_reg(guc, i),
76 					FW_REG_READ | FW_REG_WRITE);
77 	}
78 	guc->send_regs.fw_domains = fw_domains;
79 }
80 
81 static void gen9_reset_guc_interrupts(struct intel_guc *guc)
82 {
83 	struct intel_gt *gt = guc_to_gt(guc);
84 
85 	assert_rpm_wakelock_held(&gt->i915->runtime_pm);
86 
87 	spin_lock_irq(&gt->irq_lock);
88 	gen6_gt_pm_reset_iir(gt, gt->pm_guc_events);
89 	spin_unlock_irq(&gt->irq_lock);
90 }
91 
92 static void gen9_enable_guc_interrupts(struct intel_guc *guc)
93 {
94 	struct intel_gt *gt = guc_to_gt(guc);
95 
96 	assert_rpm_wakelock_held(&gt->i915->runtime_pm);
97 
98 	spin_lock_irq(&gt->irq_lock);
99 	if (!guc->interrupts.enabled) {
100 		WARN_ON_ONCE(intel_uncore_read(gt->uncore, GEN8_GT_IIR(2)) &
101 			     gt->pm_guc_events);
102 		guc->interrupts.enabled = true;
103 		gen6_gt_pm_enable_irq(gt, gt->pm_guc_events);
104 	}
105 	spin_unlock_irq(&gt->irq_lock);
106 }
107 
108 static void gen9_disable_guc_interrupts(struct intel_guc *guc)
109 {
110 	struct intel_gt *gt = guc_to_gt(guc);
111 
112 	assert_rpm_wakelock_held(&gt->i915->runtime_pm);
113 
114 	spin_lock_irq(&gt->irq_lock);
115 	guc->interrupts.enabled = false;
116 
117 	gen6_gt_pm_disable_irq(gt, gt->pm_guc_events);
118 
119 	spin_unlock_irq(&gt->irq_lock);
120 	intel_synchronize_irq(gt->i915);
121 
122 	gen9_reset_guc_interrupts(guc);
123 }
124 
125 static void gen11_reset_guc_interrupts(struct intel_guc *guc)
126 {
127 	struct intel_gt *gt = guc_to_gt(guc);
128 
129 	spin_lock_irq(&gt->irq_lock);
130 	gen11_gt_reset_one_iir(gt, 0, GEN11_GUC);
131 	spin_unlock_irq(&gt->irq_lock);
132 }
133 
134 static void gen11_enable_guc_interrupts(struct intel_guc *guc)
135 {
136 	struct intel_gt *gt = guc_to_gt(guc);
137 
138 	spin_lock_irq(&gt->irq_lock);
139 	if (!guc->interrupts.enabled) {
140 		u32 events = REG_FIELD_PREP(ENGINE1_MASK, GUC_INTR_GUC2HOST);
141 
142 		WARN_ON_ONCE(gen11_gt_reset_one_iir(gt, 0, GEN11_GUC));
143 		intel_uncore_write(gt->uncore,
144 				   GEN11_GUC_SG_INTR_ENABLE, events);
145 		intel_uncore_write(gt->uncore,
146 				   GEN11_GUC_SG_INTR_MASK, ~events);
147 		guc->interrupts.enabled = true;
148 	}
149 	spin_unlock_irq(&gt->irq_lock);
150 }
151 
152 static void gen11_disable_guc_interrupts(struct intel_guc *guc)
153 {
154 	struct intel_gt *gt = guc_to_gt(guc);
155 
156 	spin_lock_irq(&gt->irq_lock);
157 	guc->interrupts.enabled = false;
158 
159 	intel_uncore_write(gt->uncore, GEN11_GUC_SG_INTR_MASK, ~0);
160 	intel_uncore_write(gt->uncore, GEN11_GUC_SG_INTR_ENABLE, 0);
161 
162 	spin_unlock_irq(&gt->irq_lock);
163 	intel_synchronize_irq(gt->i915);
164 
165 	gen11_reset_guc_interrupts(guc);
166 }
167 
168 void intel_guc_init_early(struct intel_guc *guc)
169 {
170 	struct drm_i915_private *i915 = guc_to_gt(guc)->i915;
171 
172 	intel_uc_fw_init_early(&guc->fw, INTEL_UC_FW_TYPE_GUC);
173 	intel_guc_ct_init_early(&guc->ct);
174 	intel_guc_log_init_early(&guc->log);
175 	intel_guc_submission_init_early(guc);
176 
177 	mutex_init(&guc->send_mutex);
178 	spin_lock_init(&guc->irq_lock);
179 	if (INTEL_GEN(i915) >= 11) {
180 		guc->notify_reg = GEN11_GUC_HOST_INTERRUPT;
181 		guc->interrupts.reset = gen11_reset_guc_interrupts;
182 		guc->interrupts.enable = gen11_enable_guc_interrupts;
183 		guc->interrupts.disable = gen11_disable_guc_interrupts;
184 	} else {
185 		guc->notify_reg = GUC_SEND_INTERRUPT;
186 		guc->interrupts.reset = gen9_reset_guc_interrupts;
187 		guc->interrupts.enable = gen9_enable_guc_interrupts;
188 		guc->interrupts.disable = gen9_disable_guc_interrupts;
189 	}
190 }
191 
192 static u32 guc_ctl_debug_flags(struct intel_guc *guc)
193 {
194 	u32 level = intel_guc_log_get_level(&guc->log);
195 	u32 flags = 0;
196 
197 	if (!GUC_LOG_LEVEL_IS_VERBOSE(level))
198 		flags |= GUC_LOG_DISABLED;
199 	else
200 		flags |= GUC_LOG_LEVEL_TO_VERBOSITY(level) <<
201 			 GUC_LOG_VERBOSITY_SHIFT;
202 
203 	return flags;
204 }
205 
206 static u32 guc_ctl_feature_flags(struct intel_guc *guc)
207 {
208 	u32 flags = 0;
209 
210 	if (!intel_guc_submission_is_used(guc))
211 		flags |= GUC_CTL_DISABLE_SCHEDULER;
212 
213 	return flags;
214 }
215 
216 static u32 guc_ctl_log_params_flags(struct intel_guc *guc)
217 {
218 	u32 offset = intel_guc_ggtt_offset(guc, guc->log.vma) >> PAGE_SHIFT;
219 	u32 flags;
220 
221 	#if (((CRASH_BUFFER_SIZE) % SZ_1M) == 0)
222 	#define UNIT SZ_1M
223 	#define FLAG GUC_LOG_ALLOC_IN_MEGABYTE
224 	#else
225 	#define UNIT SZ_4K
226 	#define FLAG 0
227 	#endif
228 
229 	BUILD_BUG_ON(!CRASH_BUFFER_SIZE);
230 	BUILD_BUG_ON(!IS_ALIGNED(CRASH_BUFFER_SIZE, UNIT));
231 	BUILD_BUG_ON(!DPC_BUFFER_SIZE);
232 	BUILD_BUG_ON(!IS_ALIGNED(DPC_BUFFER_SIZE, UNIT));
233 	BUILD_BUG_ON(!ISR_BUFFER_SIZE);
234 	BUILD_BUG_ON(!IS_ALIGNED(ISR_BUFFER_SIZE, UNIT));
235 
236 	BUILD_BUG_ON((CRASH_BUFFER_SIZE / UNIT - 1) >
237 			(GUC_LOG_CRASH_MASK >> GUC_LOG_CRASH_SHIFT));
238 	BUILD_BUG_ON((DPC_BUFFER_SIZE / UNIT - 1) >
239 			(GUC_LOG_DPC_MASK >> GUC_LOG_DPC_SHIFT));
240 	BUILD_BUG_ON((ISR_BUFFER_SIZE / UNIT - 1) >
241 			(GUC_LOG_ISR_MASK >> GUC_LOG_ISR_SHIFT));
242 
243 	flags = GUC_LOG_VALID |
244 		GUC_LOG_NOTIFY_ON_HALF_FULL |
245 		FLAG |
246 		((CRASH_BUFFER_SIZE / UNIT - 1) << GUC_LOG_CRASH_SHIFT) |
247 		((DPC_BUFFER_SIZE / UNIT - 1) << GUC_LOG_DPC_SHIFT) |
248 		((ISR_BUFFER_SIZE / UNIT - 1) << GUC_LOG_ISR_SHIFT) |
249 		(offset << GUC_LOG_BUF_ADDR_SHIFT);
250 
251 	#undef UNIT
252 	#undef FLAG
253 
254 	return flags;
255 }
256 
257 static u32 guc_ctl_ads_flags(struct intel_guc *guc)
258 {
259 	u32 ads = intel_guc_ggtt_offset(guc, guc->ads_vma) >> PAGE_SHIFT;
260 	u32 flags = ads << GUC_ADS_ADDR_SHIFT;
261 
262 	return flags;
263 }
264 
265 /*
266  * Initialise the GuC parameter block before starting the firmware
267  * transfer. These parameters are read by the firmware on startup
268  * and cannot be changed thereafter.
269  */
270 static void guc_init_params(struct intel_guc *guc)
271 {
272 	u32 *params = guc->params;
273 	int i;
274 
275 	BUILD_BUG_ON(sizeof(guc->params) != GUC_CTL_MAX_DWORDS * sizeof(u32));
276 
277 	params[GUC_CTL_LOG_PARAMS] = guc_ctl_log_params_flags(guc);
278 	params[GUC_CTL_FEATURE] = guc_ctl_feature_flags(guc);
279 	params[GUC_CTL_DEBUG] = guc_ctl_debug_flags(guc);
280 	params[GUC_CTL_ADS] = guc_ctl_ads_flags(guc);
281 
282 	for (i = 0; i < GUC_CTL_MAX_DWORDS; i++)
283 		DRM_DEBUG_DRIVER("param[%2d] = %#x\n", i, params[i]);
284 }
285 
286 /*
287  * Initialise the GuC parameter block before starting the firmware
288  * transfer. These parameters are read by the firmware on startup
289  * and cannot be changed thereafter.
290  */
291 void intel_guc_write_params(struct intel_guc *guc)
292 {
293 	struct intel_uncore *uncore = guc_to_gt(guc)->uncore;
294 	int i;
295 
296 	/*
297 	 * All SOFT_SCRATCH registers are in FORCEWAKE_GT domain and
298 	 * they are power context saved so it's ok to release forcewake
299 	 * when we are done here and take it again at xfer time.
300 	 */
301 	intel_uncore_forcewake_get(uncore, FORCEWAKE_GT);
302 
303 	intel_uncore_write(uncore, SOFT_SCRATCH(0), 0);
304 
305 	for (i = 0; i < GUC_CTL_MAX_DWORDS; i++)
306 		intel_uncore_write(uncore, SOFT_SCRATCH(1 + i), guc->params[i]);
307 
308 	intel_uncore_forcewake_put(uncore, FORCEWAKE_GT);
309 }
310 
311 int intel_guc_init(struct intel_guc *guc)
312 {
313 	struct intel_gt *gt = guc_to_gt(guc);
314 	int ret;
315 
316 	ret = intel_uc_fw_init(&guc->fw);
317 	if (ret)
318 		goto out;
319 
320 	ret = intel_guc_log_create(&guc->log);
321 	if (ret)
322 		goto err_fw;
323 
324 	ret = intel_guc_ads_create(guc);
325 	if (ret)
326 		goto err_log;
327 	GEM_BUG_ON(!guc->ads_vma);
328 
329 	ret = intel_guc_ct_init(&guc->ct);
330 	if (ret)
331 		goto err_ads;
332 
333 	if (intel_guc_submission_is_used(guc)) {
334 		/*
335 		 * This is stuff we need to have available at fw load time
336 		 * if we are planning to enable submission later
337 		 */
338 		ret = intel_guc_submission_init(guc);
339 		if (ret)
340 			goto err_ct;
341 	}
342 
343 	/* now that everything is perma-pinned, initialize the parameters */
344 	guc_init_params(guc);
345 
346 	/* We need to notify the guc whenever we change the GGTT */
347 	i915_ggtt_enable_guc(gt->ggtt);
348 
349 	intel_uc_fw_change_status(&guc->fw, INTEL_UC_FIRMWARE_LOADABLE);
350 
351 	return 0;
352 
353 err_ct:
354 	intel_guc_ct_fini(&guc->ct);
355 err_ads:
356 	intel_guc_ads_destroy(guc);
357 err_log:
358 	intel_guc_log_destroy(&guc->log);
359 err_fw:
360 	intel_uc_fw_fini(&guc->fw);
361 out:
362 	i915_probe_error(gt->i915, "failed with %d\n", ret);
363 	return ret;
364 }
365 
366 void intel_guc_fini(struct intel_guc *guc)
367 {
368 	struct intel_gt *gt = guc_to_gt(guc);
369 
370 	if (!intel_uc_fw_is_loadable(&guc->fw))
371 		return;
372 
373 	i915_ggtt_disable_guc(gt->ggtt);
374 
375 	if (intel_guc_submission_is_used(guc))
376 		intel_guc_submission_fini(guc);
377 
378 	intel_guc_ct_fini(&guc->ct);
379 
380 	intel_guc_ads_destroy(guc);
381 	intel_guc_log_destroy(&guc->log);
382 	intel_uc_fw_fini(&guc->fw);
383 }
384 
385 /*
386  * This function implements the MMIO based host to GuC interface.
387  */
388 int intel_guc_send_mmio(struct intel_guc *guc, const u32 *action, u32 len,
389 			u32 *response_buf, u32 response_buf_size)
390 {
391 	struct intel_uncore *uncore = guc_to_gt(guc)->uncore;
392 	u32 status;
393 	int i;
394 	int ret;
395 
396 	GEM_BUG_ON(!len);
397 	GEM_BUG_ON(len > guc->send_regs.count);
398 
399 	/* We expect only action code */
400 	GEM_BUG_ON(*action & ~INTEL_GUC_MSG_CODE_MASK);
401 
402 	/* If CT is available, we expect to use MMIO only during init/fini */
403 	GEM_BUG_ON(*action != INTEL_GUC_ACTION_REGISTER_COMMAND_TRANSPORT_BUFFER &&
404 		   *action != INTEL_GUC_ACTION_DEREGISTER_COMMAND_TRANSPORT_BUFFER);
405 
406 	mutex_lock(&guc->send_mutex);
407 	intel_uncore_forcewake_get(uncore, guc->send_regs.fw_domains);
408 
409 	for (i = 0; i < len; i++)
410 		intel_uncore_write(uncore, guc_send_reg(guc, i), action[i]);
411 
412 	intel_uncore_posting_read(uncore, guc_send_reg(guc, i - 1));
413 
414 	intel_guc_notify(guc);
415 
416 	/*
417 	 * No GuC command should ever take longer than 10ms.
418 	 * Fast commands should still complete in 10us.
419 	 */
420 	ret = __intel_wait_for_register_fw(uncore,
421 					   guc_send_reg(guc, 0),
422 					   INTEL_GUC_MSG_TYPE_MASK,
423 					   INTEL_GUC_MSG_TYPE_RESPONSE <<
424 					   INTEL_GUC_MSG_TYPE_SHIFT,
425 					   10, 10, &status);
426 	/* If GuC explicitly returned an error, convert it to -EIO */
427 	if (!ret && !INTEL_GUC_MSG_IS_RESPONSE_SUCCESS(status))
428 		ret = -EIO;
429 
430 	if (ret) {
431 		DRM_ERROR("MMIO: GuC action %#x failed with error %d %#x\n",
432 			  action[0], ret, status);
433 		goto out;
434 	}
435 
436 	if (response_buf) {
437 		int count = min(response_buf_size, guc->send_regs.count - 1);
438 
439 		for (i = 0; i < count; i++)
440 			response_buf[i] = intel_uncore_read(uncore,
441 							    guc_send_reg(guc, i + 1));
442 	}
443 
444 	/* Use data from the GuC response as our return value */
445 	ret = INTEL_GUC_MSG_TO_DATA(status);
446 
447 out:
448 	intel_uncore_forcewake_put(uncore, guc->send_regs.fw_domains);
449 	mutex_unlock(&guc->send_mutex);
450 
451 	return ret;
452 }
453 
454 int intel_guc_to_host_process_recv_msg(struct intel_guc *guc,
455 				       const u32 *payload, u32 len)
456 {
457 	u32 msg;
458 
459 	if (unlikely(!len))
460 		return -EPROTO;
461 
462 	/* Make sure to handle only enabled messages */
463 	msg = payload[0] & guc->msg_enabled_mask;
464 
465 	if (msg & (INTEL_GUC_RECV_MSG_FLUSH_LOG_BUFFER |
466 		   INTEL_GUC_RECV_MSG_CRASH_DUMP_POSTED))
467 		intel_guc_log_handle_flush_event(&guc->log);
468 
469 	return 0;
470 }
471 
472 int intel_guc_sample_forcewake(struct intel_guc *guc)
473 {
474 	struct drm_i915_private *dev_priv = guc_to_gt(guc)->i915;
475 	u32 action[2];
476 
477 	action[0] = INTEL_GUC_ACTION_SAMPLE_FORCEWAKE;
478 	/* WaRsDisableCoarsePowerGating:skl,cnl */
479 	if (!HAS_RC6(dev_priv) || NEEDS_WaRsDisableCoarsePowerGating(dev_priv))
480 		action[1] = 0;
481 	else
482 		/* bit 0 and 1 are for Render and Media domain separately */
483 		action[1] = GUC_FORCEWAKE_RENDER | GUC_FORCEWAKE_MEDIA;
484 
485 	return intel_guc_send(guc, action, ARRAY_SIZE(action));
486 }
487 
488 /**
489  * intel_guc_auth_huc() - Send action to GuC to authenticate HuC ucode
490  * @guc: intel_guc structure
491  * @rsa_offset: rsa offset w.r.t ggtt base of huc vma
492  *
493  * Triggers a HuC firmware authentication request to the GuC via intel_guc_send
494  * INTEL_GUC_ACTION_AUTHENTICATE_HUC interface. This function is invoked by
495  * intel_huc_auth().
496  *
497  * Return:	non-zero code on error
498  */
499 int intel_guc_auth_huc(struct intel_guc *guc, u32 rsa_offset)
500 {
501 	u32 action[] = {
502 		INTEL_GUC_ACTION_AUTHENTICATE_HUC,
503 		rsa_offset
504 	};
505 
506 	return intel_guc_send(guc, action, ARRAY_SIZE(action));
507 }
508 
509 /**
510  * intel_guc_suspend() - notify GuC entering suspend state
511  * @guc:	the guc
512  */
513 int intel_guc_suspend(struct intel_guc *guc)
514 {
515 	struct intel_uncore *uncore = guc_to_gt(guc)->uncore;
516 	int ret;
517 	u32 status;
518 	u32 action[] = {
519 		INTEL_GUC_ACTION_ENTER_S_STATE,
520 		GUC_POWER_D1, /* any value greater than GUC_POWER_D0 */
521 	};
522 
523 	/*
524 	 * If GuC communication is enabled but submission is not supported,
525 	 * we do not need to suspend the GuC.
526 	 */
527 	if (!intel_guc_submission_is_used(guc) || !intel_guc_is_ready(guc))
528 		return 0;
529 
530 	/*
531 	 * The ENTER_S_STATE action queues the save/restore operation in GuC FW
532 	 * and then returns, so waiting on the H2G is not enough to guarantee
533 	 * GuC is done. When all the processing is done, GuC writes
534 	 * INTEL_GUC_SLEEP_STATE_SUCCESS to scratch register 14, so we can poll
535 	 * on that. Note that GuC does not ensure that the value in the register
536 	 * is different from INTEL_GUC_SLEEP_STATE_SUCCESS while the action is
537 	 * in progress so we need to take care of that ourselves as well.
538 	 */
539 
540 	intel_uncore_write(uncore, SOFT_SCRATCH(14),
541 			   INTEL_GUC_SLEEP_STATE_INVALID_MASK);
542 
543 	ret = intel_guc_send(guc, action, ARRAY_SIZE(action));
544 	if (ret)
545 		return ret;
546 
547 	ret = __intel_wait_for_register(uncore, SOFT_SCRATCH(14),
548 					INTEL_GUC_SLEEP_STATE_INVALID_MASK,
549 					0, 0, 10, &status);
550 	if (ret)
551 		return ret;
552 
553 	if (status != INTEL_GUC_SLEEP_STATE_SUCCESS) {
554 		DRM_ERROR("GuC failed to change sleep state. "
555 			  "action=0x%x, err=%u\n",
556 			  action[0], status);
557 		return -EIO;
558 	}
559 
560 	return 0;
561 }
562 
563 /**
564  * intel_guc_reset_engine() - ask GuC to reset an engine
565  * @guc:	intel_guc structure
566  * @engine:	engine to be reset
567  */
568 int intel_guc_reset_engine(struct intel_guc *guc,
569 			   struct intel_engine_cs *engine)
570 {
571 	/* XXX: to be implemented with submission interface rework */
572 
573 	return -ENODEV;
574 }
575 
576 /**
577  * intel_guc_resume() - notify GuC resuming from suspend state
578  * @guc:	the guc
579  */
580 int intel_guc_resume(struct intel_guc *guc)
581 {
582 	/* XXX: to be implemented with submission interface rework */
583 	return 0;
584 }
585 
586 /**
587  * DOC: GuC Memory Management
588  *
589  * GuC can't allocate any memory for its own usage, so all the allocations must
590  * be handled by the host driver. GuC accesses the memory via the GGTT, with the
591  * exception of the top and bottom parts of the 4GB address space, which are
592  * instead re-mapped by the GuC HW to memory location of the FW itself (WOPCM)
593  * or other parts of the HW. The driver must take care not to place objects that
594  * the GuC is going to access in these reserved ranges. The layout of the GuC
595  * address space is shown below:
596  *
597  * ::
598  *
599  *     +===========> +====================+ <== FFFF_FFFF
600  *     ^             |      Reserved      |
601  *     |             +====================+ <== GUC_GGTT_TOP
602  *     |             |                    |
603  *     |             |        DRAM        |
604  *    GuC            |                    |
605  *  Address    +===> +====================+ <== GuC ggtt_pin_bias
606  *   Space     ^     |                    |
607  *     |       |     |                    |
608  *     |      GuC    |        GuC         |
609  *     |     WOPCM   |       WOPCM        |
610  *     |      Size   |                    |
611  *     |       |     |                    |
612  *     v       v     |                    |
613  *     +=======+===> +====================+ <== 0000_0000
614  *
615  * The lower part of GuC Address Space [0, ggtt_pin_bias) is mapped to GuC WOPCM
616  * while upper part of GuC Address Space [ggtt_pin_bias, GUC_GGTT_TOP) is mapped
617  * to DRAM. The value of the GuC ggtt_pin_bias is the GuC WOPCM size.
618  */
619 
620 /**
621  * intel_guc_allocate_vma() - Allocate a GGTT VMA for GuC usage
622  * @guc:	the guc
623  * @size:	size of area to allocate (both virtual space and memory)
624  *
625  * This is a wrapper to create an object for use with the GuC. In order to
626  * use it inside the GuC, an object needs to be pinned lifetime, so we allocate
627  * both some backing storage and a range inside the Global GTT. We must pin
628  * it in the GGTT somewhere other than than [0, GUC ggtt_pin_bias) because that
629  * range is reserved inside GuC.
630  *
631  * Return:	A i915_vma if successful, otherwise an ERR_PTR.
632  */
633 struct i915_vma *intel_guc_allocate_vma(struct intel_guc *guc, u32 size)
634 {
635 	struct intel_gt *gt = guc_to_gt(guc);
636 	struct drm_i915_gem_object *obj;
637 	struct i915_vma *vma;
638 	u64 flags;
639 	int ret;
640 
641 	obj = i915_gem_object_create_shmem(gt->i915, size);
642 	if (IS_ERR(obj))
643 		return ERR_CAST(obj);
644 
645 	vma = i915_vma_instance(obj, &gt->ggtt->vm, NULL);
646 	if (IS_ERR(vma))
647 		goto err;
648 
649 	flags = PIN_OFFSET_BIAS | i915_ggtt_pin_bias(vma);
650 	ret = i915_ggtt_pin(vma, NULL, 0, flags);
651 	if (ret) {
652 		vma = ERR_PTR(ret);
653 		goto err;
654 	}
655 
656 	return i915_vma_make_unshrinkable(vma);
657 
658 err:
659 	i915_gem_object_put(obj);
660 	return vma;
661 }
662 
663 /**
664  * intel_guc_allocate_and_map_vma() - Allocate and map VMA for GuC usage
665  * @guc:	the guc
666  * @size:	size of area to allocate (both virtual space and memory)
667  * @out_vma:	return variable for the allocated vma pointer
668  * @out_vaddr:	return variable for the obj mapping
669  *
670  * This wrapper calls intel_guc_allocate_vma() and then maps the allocated
671  * object with I915_MAP_WB.
672  *
673  * Return:	0 if successful, a negative errno code otherwise.
674  */
675 int intel_guc_allocate_and_map_vma(struct intel_guc *guc, u32 size,
676 				   struct i915_vma **out_vma, void **out_vaddr)
677 {
678 	struct i915_vma *vma;
679 	void *vaddr;
680 
681 	vma = intel_guc_allocate_vma(guc, size);
682 	if (IS_ERR(vma))
683 		return PTR_ERR(vma);
684 
685 	vaddr = i915_gem_object_pin_map_unlocked(vma->obj, I915_MAP_WB);
686 	if (IS_ERR(vaddr)) {
687 		i915_vma_unpin_and_release(&vma, 0);
688 		return PTR_ERR(vaddr);
689 	}
690 
691 	*out_vma = vma;
692 	*out_vaddr = vaddr;
693 
694 	return 0;
695 }
696 
697 /**
698  * intel_guc_load_status - dump information about GuC load status
699  * @guc: the GuC
700  * @p: the &drm_printer
701  *
702  * Pretty printer for GuC load status.
703  */
704 void intel_guc_load_status(struct intel_guc *guc, struct drm_printer *p)
705 {
706 	struct intel_gt *gt = guc_to_gt(guc);
707 	struct intel_uncore *uncore = gt->uncore;
708 	intel_wakeref_t wakeref;
709 
710 	if (!intel_guc_is_supported(guc)) {
711 		drm_printf(p, "GuC not supported\n");
712 		return;
713 	}
714 
715 	if (!intel_guc_is_wanted(guc)) {
716 		drm_printf(p, "GuC disabled\n");
717 		return;
718 	}
719 
720 	intel_uc_fw_dump(&guc->fw, p);
721 
722 	with_intel_runtime_pm(uncore->rpm, wakeref) {
723 		u32 status = intel_uncore_read(uncore, GUC_STATUS);
724 		u32 i;
725 
726 		drm_printf(p, "\nGuC status 0x%08x:\n", status);
727 		drm_printf(p, "\tBootrom status = 0x%x\n",
728 			   (status & GS_BOOTROM_MASK) >> GS_BOOTROM_SHIFT);
729 		drm_printf(p, "\tuKernel status = 0x%x\n",
730 			   (status & GS_UKERNEL_MASK) >> GS_UKERNEL_SHIFT);
731 		drm_printf(p, "\tMIA Core status = 0x%x\n",
732 			   (status & GS_MIA_MASK) >> GS_MIA_SHIFT);
733 		drm_puts(p, "\nScratch registers:\n");
734 		for (i = 0; i < 16; i++) {
735 			drm_printf(p, "\t%2d: \t0x%x\n",
736 				   i, intel_uncore_read(uncore, SOFT_SCRATCH(i)));
737 		}
738 	}
739 }
740