xref: /openbmc/linux/drivers/gpu/drm/i915/gt/uc/intel_guc.c (revision 2cf1c348)
1 // SPDX-License-Identifier: MIT
2 /*
3  * Copyright © 2014-2019 Intel Corporation
4  */
5 
6 #include "gem/i915_gem_lmem.h"
7 #include "gt/intel_gt.h"
8 #include "gt/intel_gt_irq.h"
9 #include "gt/intel_gt_pm_irq.h"
10 #include "intel_guc.h"
11 #include "intel_guc_slpc.h"
12 #include "intel_guc_ads.h"
13 #include "intel_guc_submission.h"
14 #include "i915_drv.h"
15 
16 /**
17  * DOC: GuC
18  *
19  * The GuC is a microcontroller inside the GT HW, introduced in gen9. The GuC is
20  * designed to offload some of the functionality usually performed by the host
21  * driver; currently the main operations it can take care of are:
22  *
23  * - Authentication of the HuC, which is required to fully enable HuC usage.
24  * - Low latency graphics context scheduling (a.k.a. GuC submission).
25  * - GT Power management.
26  *
27  * The enable_guc module parameter can be used to select which of those
28  * operations to enable within GuC. Note that not all the operations are
29  * supported on all gen9+ platforms.
30  *
31  * Enabling the GuC is not mandatory and therefore the firmware is only loaded
32  * if at least one of the operations is selected. However, not loading the GuC
33  * might result in the loss of some features that do require the GuC (currently
34  * just the HuC, but more are expected to land in the future).
35  */
36 
37 void intel_guc_notify(struct intel_guc *guc)
38 {
39 	struct intel_gt *gt = guc_to_gt(guc);
40 
41 	/*
42 	 * On Gen11+, the value written to the register is passes as a payload
43 	 * to the FW. However, the FW currently treats all values the same way
44 	 * (H2G interrupt), so we can just write the value that the HW expects
45 	 * on older gens.
46 	 */
47 	intel_uncore_write(gt->uncore, guc->notify_reg, GUC_SEND_TRIGGER);
48 }
49 
50 static inline i915_reg_t guc_send_reg(struct intel_guc *guc, u32 i)
51 {
52 	GEM_BUG_ON(!guc->send_regs.base);
53 	GEM_BUG_ON(!guc->send_regs.count);
54 	GEM_BUG_ON(i >= guc->send_regs.count);
55 
56 	return _MMIO(guc->send_regs.base + 4 * i);
57 }
58 
59 void intel_guc_init_send_regs(struct intel_guc *guc)
60 {
61 	struct intel_gt *gt = guc_to_gt(guc);
62 	enum forcewake_domains fw_domains = 0;
63 	unsigned int i;
64 
65 	GEM_BUG_ON(!guc->send_regs.base);
66 	GEM_BUG_ON(!guc->send_regs.count);
67 
68 	for (i = 0; i < guc->send_regs.count; i++) {
69 		fw_domains |= intel_uncore_forcewake_for_reg(gt->uncore,
70 					guc_send_reg(guc, i),
71 					FW_REG_READ | FW_REG_WRITE);
72 	}
73 	guc->send_regs.fw_domains = fw_domains;
74 }
75 
76 static void gen9_reset_guc_interrupts(struct intel_guc *guc)
77 {
78 	struct intel_gt *gt = guc_to_gt(guc);
79 
80 	assert_rpm_wakelock_held(&gt->i915->runtime_pm);
81 
82 	spin_lock_irq(&gt->irq_lock);
83 	gen6_gt_pm_reset_iir(gt, gt->pm_guc_events);
84 	spin_unlock_irq(&gt->irq_lock);
85 }
86 
87 static void gen9_enable_guc_interrupts(struct intel_guc *guc)
88 {
89 	struct intel_gt *gt = guc_to_gt(guc);
90 
91 	assert_rpm_wakelock_held(&gt->i915->runtime_pm);
92 
93 	spin_lock_irq(&gt->irq_lock);
94 	WARN_ON_ONCE(intel_uncore_read(gt->uncore, GEN8_GT_IIR(2)) &
95 		     gt->pm_guc_events);
96 	gen6_gt_pm_enable_irq(gt, gt->pm_guc_events);
97 	spin_unlock_irq(&gt->irq_lock);
98 }
99 
100 static void gen9_disable_guc_interrupts(struct intel_guc *guc)
101 {
102 	struct intel_gt *gt = guc_to_gt(guc);
103 
104 	assert_rpm_wakelock_held(&gt->i915->runtime_pm);
105 
106 	spin_lock_irq(&gt->irq_lock);
107 
108 	gen6_gt_pm_disable_irq(gt, gt->pm_guc_events);
109 
110 	spin_unlock_irq(&gt->irq_lock);
111 	intel_synchronize_irq(gt->i915);
112 
113 	gen9_reset_guc_interrupts(guc);
114 }
115 
116 static void gen11_reset_guc_interrupts(struct intel_guc *guc)
117 {
118 	struct intel_gt *gt = guc_to_gt(guc);
119 
120 	spin_lock_irq(&gt->irq_lock);
121 	gen11_gt_reset_one_iir(gt, 0, GEN11_GUC);
122 	spin_unlock_irq(&gt->irq_lock);
123 }
124 
125 static void gen11_enable_guc_interrupts(struct intel_guc *guc)
126 {
127 	struct intel_gt *gt = guc_to_gt(guc);
128 	u32 events = REG_FIELD_PREP(ENGINE1_MASK, GUC_INTR_GUC2HOST);
129 
130 	spin_lock_irq(&gt->irq_lock);
131 	WARN_ON_ONCE(gen11_gt_reset_one_iir(gt, 0, GEN11_GUC));
132 	intel_uncore_write(gt->uncore,
133 			   GEN11_GUC_SG_INTR_ENABLE, events);
134 	intel_uncore_write(gt->uncore,
135 			   GEN11_GUC_SG_INTR_MASK, ~events);
136 	spin_unlock_irq(&gt->irq_lock);
137 }
138 
139 static void gen11_disable_guc_interrupts(struct intel_guc *guc)
140 {
141 	struct intel_gt *gt = guc_to_gt(guc);
142 
143 	spin_lock_irq(&gt->irq_lock);
144 
145 	intel_uncore_write(gt->uncore, GEN11_GUC_SG_INTR_MASK, ~0);
146 	intel_uncore_write(gt->uncore, GEN11_GUC_SG_INTR_ENABLE, 0);
147 
148 	spin_unlock_irq(&gt->irq_lock);
149 	intel_synchronize_irq(gt->i915);
150 
151 	gen11_reset_guc_interrupts(guc);
152 }
153 
154 void intel_guc_init_early(struct intel_guc *guc)
155 {
156 	struct drm_i915_private *i915 = guc_to_gt(guc)->i915;
157 
158 	intel_uc_fw_init_early(&guc->fw, INTEL_UC_FW_TYPE_GUC);
159 	intel_guc_ct_init_early(&guc->ct);
160 	intel_guc_log_init_early(&guc->log);
161 	intel_guc_submission_init_early(guc);
162 	intel_guc_slpc_init_early(&guc->slpc);
163 	intel_guc_rc_init_early(guc);
164 
165 	mutex_init(&guc->send_mutex);
166 	spin_lock_init(&guc->irq_lock);
167 	if (GRAPHICS_VER(i915) >= 11) {
168 		guc->notify_reg = GEN11_GUC_HOST_INTERRUPT;
169 		guc->interrupts.reset = gen11_reset_guc_interrupts;
170 		guc->interrupts.enable = gen11_enable_guc_interrupts;
171 		guc->interrupts.disable = gen11_disable_guc_interrupts;
172 		guc->send_regs.base =
173 			i915_mmio_reg_offset(GEN11_SOFT_SCRATCH(0));
174 		guc->send_regs.count = GEN11_SOFT_SCRATCH_COUNT;
175 
176 	} else {
177 		guc->notify_reg = GUC_SEND_INTERRUPT;
178 		guc->interrupts.reset = gen9_reset_guc_interrupts;
179 		guc->interrupts.enable = gen9_enable_guc_interrupts;
180 		guc->interrupts.disable = gen9_disable_guc_interrupts;
181 		guc->send_regs.base = i915_mmio_reg_offset(SOFT_SCRATCH(0));
182 		guc->send_regs.count = GUC_MAX_MMIO_MSG_LEN;
183 		BUILD_BUG_ON(GUC_MAX_MMIO_MSG_LEN > SOFT_SCRATCH_COUNT);
184 	}
185 }
186 
187 void intel_guc_init_late(struct intel_guc *guc)
188 {
189 	intel_guc_ads_init_late(guc);
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 	if (intel_guc_slpc_is_used(guc))
214 		flags |= GUC_CTL_ENABLE_SLPC;
215 
216 	return flags;
217 }
218 
219 static u32 guc_ctl_log_params_flags(struct intel_guc *guc)
220 {
221 	u32 offset = intel_guc_ggtt_offset(guc, guc->log.vma) >> PAGE_SHIFT;
222 	u32 flags;
223 
224 	#if (((CRASH_BUFFER_SIZE) % SZ_1M) == 0)
225 	#define UNIT SZ_1M
226 	#define FLAG GUC_LOG_ALLOC_IN_MEGABYTE
227 	#else
228 	#define UNIT SZ_4K
229 	#define FLAG 0
230 	#endif
231 
232 	BUILD_BUG_ON(!CRASH_BUFFER_SIZE);
233 	BUILD_BUG_ON(!IS_ALIGNED(CRASH_BUFFER_SIZE, UNIT));
234 	BUILD_BUG_ON(!DEBUG_BUFFER_SIZE);
235 	BUILD_BUG_ON(!IS_ALIGNED(DEBUG_BUFFER_SIZE, UNIT));
236 
237 	BUILD_BUG_ON((CRASH_BUFFER_SIZE / UNIT - 1) >
238 			(GUC_LOG_CRASH_MASK >> GUC_LOG_CRASH_SHIFT));
239 	BUILD_BUG_ON((DEBUG_BUFFER_SIZE / UNIT - 1) >
240 			(GUC_LOG_DEBUG_MASK >> GUC_LOG_DEBUG_SHIFT));
241 
242 	flags = GUC_LOG_VALID |
243 		GUC_LOG_NOTIFY_ON_HALF_FULL |
244 		FLAG |
245 		((CRASH_BUFFER_SIZE / UNIT - 1) << GUC_LOG_CRASH_SHIFT) |
246 		((DEBUG_BUFFER_SIZE / UNIT - 1) << GUC_LOG_DEBUG_SHIFT) |
247 		(offset << GUC_LOG_BUF_ADDR_SHIFT);
248 
249 	#undef UNIT
250 	#undef FLAG
251 
252 	return flags;
253 }
254 
255 static u32 guc_ctl_ads_flags(struct intel_guc *guc)
256 {
257 	u32 ads = intel_guc_ggtt_offset(guc, guc->ads_vma) >> PAGE_SHIFT;
258 	u32 flags = ads << GUC_ADS_ADDR_SHIFT;
259 
260 	return flags;
261 }
262 
263 /*
264  * Initialise the GuC parameter block before starting the firmware
265  * transfer. These parameters are read by the firmware on startup
266  * and cannot be changed thereafter.
267  */
268 static void guc_init_params(struct intel_guc *guc)
269 {
270 	u32 *params = guc->params;
271 	int i;
272 
273 	BUILD_BUG_ON(sizeof(guc->params) != GUC_CTL_MAX_DWORDS * sizeof(u32));
274 
275 	params[GUC_CTL_LOG_PARAMS] = guc_ctl_log_params_flags(guc);
276 	params[GUC_CTL_FEATURE] = guc_ctl_feature_flags(guc);
277 	params[GUC_CTL_DEBUG] = guc_ctl_debug_flags(guc);
278 	params[GUC_CTL_ADS] = guc_ctl_ads_flags(guc);
279 
280 	for (i = 0; i < GUC_CTL_MAX_DWORDS; i++)
281 		DRM_DEBUG_DRIVER("param[%2d] = %#x\n", i, params[i]);
282 }
283 
284 /*
285  * Initialise the GuC parameter block before starting the firmware
286  * transfer. These parameters are read by the firmware on startup
287  * and cannot be changed thereafter.
288  */
289 void intel_guc_write_params(struct intel_guc *guc)
290 {
291 	struct intel_uncore *uncore = guc_to_gt(guc)->uncore;
292 	int i;
293 
294 	/*
295 	 * All SOFT_SCRATCH registers are in FORCEWAKE_GT domain and
296 	 * they are power context saved so it's ok to release forcewake
297 	 * when we are done here and take it again at xfer time.
298 	 */
299 	intel_uncore_forcewake_get(uncore, FORCEWAKE_GT);
300 
301 	intel_uncore_write(uncore, SOFT_SCRATCH(0), 0);
302 
303 	for (i = 0; i < GUC_CTL_MAX_DWORDS; i++)
304 		intel_uncore_write(uncore, SOFT_SCRATCH(1 + i), guc->params[i]);
305 
306 	intel_uncore_forcewake_put(uncore, FORCEWAKE_GT);
307 }
308 
309 int intel_guc_init(struct intel_guc *guc)
310 {
311 	struct intel_gt *gt = guc_to_gt(guc);
312 	int ret;
313 
314 	ret = intel_uc_fw_init(&guc->fw);
315 	if (ret)
316 		goto out;
317 
318 	ret = intel_guc_log_create(&guc->log);
319 	if (ret)
320 		goto err_fw;
321 
322 	ret = intel_guc_ads_create(guc);
323 	if (ret)
324 		goto err_log;
325 	GEM_BUG_ON(!guc->ads_vma);
326 
327 	ret = intel_guc_ct_init(&guc->ct);
328 	if (ret)
329 		goto err_ads;
330 
331 	if (intel_guc_submission_is_used(guc)) {
332 		/*
333 		 * This is stuff we need to have available at fw load time
334 		 * if we are planning to enable submission later
335 		 */
336 		ret = intel_guc_submission_init(guc);
337 		if (ret)
338 			goto err_ct;
339 	}
340 
341 	if (intel_guc_slpc_is_used(guc)) {
342 		ret = intel_guc_slpc_init(&guc->slpc);
343 		if (ret)
344 			goto err_submission;
345 	}
346 
347 	/* now that everything is perma-pinned, initialize the parameters */
348 	guc_init_params(guc);
349 
350 	/* We need to notify the guc whenever we change the GGTT */
351 	i915_ggtt_enable_guc(gt->ggtt);
352 
353 	intel_uc_fw_change_status(&guc->fw, INTEL_UC_FIRMWARE_LOADABLE);
354 
355 	return 0;
356 
357 err_submission:
358 	intel_guc_submission_fini(guc);
359 err_ct:
360 	intel_guc_ct_fini(&guc->ct);
361 err_ads:
362 	intel_guc_ads_destroy(guc);
363 err_log:
364 	intel_guc_log_destroy(&guc->log);
365 err_fw:
366 	intel_uc_fw_fini(&guc->fw);
367 out:
368 	i915_probe_error(gt->i915, "failed with %d\n", ret);
369 	return ret;
370 }
371 
372 void intel_guc_fini(struct intel_guc *guc)
373 {
374 	struct intel_gt *gt = guc_to_gt(guc);
375 
376 	if (!intel_uc_fw_is_loadable(&guc->fw))
377 		return;
378 
379 	i915_ggtt_disable_guc(gt->ggtt);
380 
381 	if (intel_guc_slpc_is_used(guc))
382 		intel_guc_slpc_fini(&guc->slpc);
383 
384 	if (intel_guc_submission_is_used(guc))
385 		intel_guc_submission_fini(guc);
386 
387 	intel_guc_ct_fini(&guc->ct);
388 
389 	intel_guc_ads_destroy(guc);
390 	intel_guc_log_destroy(&guc->log);
391 	intel_uc_fw_fini(&guc->fw);
392 }
393 
394 /*
395  * This function implements the MMIO based host to GuC interface.
396  */
397 int intel_guc_send_mmio(struct intel_guc *guc, const u32 *request, u32 len,
398 			u32 *response_buf, u32 response_buf_size)
399 {
400 	struct drm_i915_private *i915 = guc_to_gt(guc)->i915;
401 	struct intel_uncore *uncore = guc_to_gt(guc)->uncore;
402 	u32 header;
403 	int i;
404 	int ret;
405 
406 	GEM_BUG_ON(!len);
407 	GEM_BUG_ON(len > guc->send_regs.count);
408 
409 	GEM_BUG_ON(FIELD_GET(GUC_HXG_MSG_0_ORIGIN, request[0]) != GUC_HXG_ORIGIN_HOST);
410 	GEM_BUG_ON(FIELD_GET(GUC_HXG_MSG_0_TYPE, request[0]) != GUC_HXG_TYPE_REQUEST);
411 
412 	mutex_lock(&guc->send_mutex);
413 	intel_uncore_forcewake_get(uncore, guc->send_regs.fw_domains);
414 
415 retry:
416 	for (i = 0; i < len; i++)
417 		intel_uncore_write(uncore, guc_send_reg(guc, i), request[i]);
418 
419 	intel_uncore_posting_read(uncore, guc_send_reg(guc, i - 1));
420 
421 	intel_guc_notify(guc);
422 
423 	/*
424 	 * No GuC command should ever take longer than 10ms.
425 	 * Fast commands should still complete in 10us.
426 	 */
427 	ret = __intel_wait_for_register_fw(uncore,
428 					   guc_send_reg(guc, 0),
429 					   GUC_HXG_MSG_0_ORIGIN,
430 					   FIELD_PREP(GUC_HXG_MSG_0_ORIGIN,
431 						      GUC_HXG_ORIGIN_GUC),
432 					   10, 10, &header);
433 	if (unlikely(ret)) {
434 timeout:
435 		drm_err(&i915->drm, "mmio request %#x: no reply %x\n",
436 			request[0], header);
437 		goto out;
438 	}
439 
440 	if (FIELD_GET(GUC_HXG_MSG_0_TYPE, header) == GUC_HXG_TYPE_NO_RESPONSE_BUSY) {
441 #define done ({ header = intel_uncore_read(uncore, guc_send_reg(guc, 0)); \
442 		FIELD_GET(GUC_HXG_MSG_0_ORIGIN, header) != GUC_HXG_ORIGIN_GUC || \
443 		FIELD_GET(GUC_HXG_MSG_0_TYPE, header) != GUC_HXG_TYPE_NO_RESPONSE_BUSY; })
444 
445 		ret = wait_for(done, 1000);
446 		if (unlikely(ret))
447 			goto timeout;
448 		if (unlikely(FIELD_GET(GUC_HXG_MSG_0_ORIGIN, header) !=
449 				       GUC_HXG_ORIGIN_GUC))
450 			goto proto;
451 #undef done
452 	}
453 
454 	if (FIELD_GET(GUC_HXG_MSG_0_TYPE, header) == GUC_HXG_TYPE_NO_RESPONSE_RETRY) {
455 		u32 reason = FIELD_GET(GUC_HXG_RETRY_MSG_0_REASON, header);
456 
457 		drm_dbg(&i915->drm, "mmio request %#x: retrying, reason %u\n",
458 			request[0], reason);
459 		goto retry;
460 	}
461 
462 	if (FIELD_GET(GUC_HXG_MSG_0_TYPE, header) == GUC_HXG_TYPE_RESPONSE_FAILURE) {
463 		u32 hint = FIELD_GET(GUC_HXG_FAILURE_MSG_0_HINT, header);
464 		u32 error = FIELD_GET(GUC_HXG_FAILURE_MSG_0_ERROR, header);
465 
466 		drm_err(&i915->drm, "mmio request %#x: failure %x/%u\n",
467 			request[0], error, hint);
468 		ret = -ENXIO;
469 		goto out;
470 	}
471 
472 	if (FIELD_GET(GUC_HXG_MSG_0_TYPE, header) != GUC_HXG_TYPE_RESPONSE_SUCCESS) {
473 proto:
474 		drm_err(&i915->drm, "mmio request %#x: unexpected reply %#x\n",
475 			request[0], header);
476 		ret = -EPROTO;
477 		goto out;
478 	}
479 
480 	if (response_buf) {
481 		int count = min(response_buf_size, guc->send_regs.count);
482 
483 		GEM_BUG_ON(!count);
484 
485 		response_buf[0] = header;
486 
487 		for (i = 1; i < count; i++)
488 			response_buf[i] = intel_uncore_read(uncore,
489 							    guc_send_reg(guc, i));
490 
491 		/* Use number of copied dwords as our return value */
492 		ret = count;
493 	} else {
494 		/* Use data from the GuC response as our return value */
495 		ret = FIELD_GET(GUC_HXG_RESPONSE_MSG_0_DATA0, header);
496 	}
497 
498 out:
499 	intel_uncore_forcewake_put(uncore, guc->send_regs.fw_domains);
500 	mutex_unlock(&guc->send_mutex);
501 
502 	return ret;
503 }
504 
505 int intel_guc_to_host_process_recv_msg(struct intel_guc *guc,
506 				       const u32 *payload, u32 len)
507 {
508 	u32 msg;
509 
510 	if (unlikely(!len))
511 		return -EPROTO;
512 
513 	/* Make sure to handle only enabled messages */
514 	msg = payload[0] & guc->msg_enabled_mask;
515 
516 	if (msg & (INTEL_GUC_RECV_MSG_FLUSH_LOG_BUFFER |
517 		   INTEL_GUC_RECV_MSG_CRASH_DUMP_POSTED))
518 		intel_guc_log_handle_flush_event(&guc->log);
519 
520 	return 0;
521 }
522 
523 /**
524  * intel_guc_auth_huc() - Send action to GuC to authenticate HuC ucode
525  * @guc: intel_guc structure
526  * @rsa_offset: rsa offset w.r.t ggtt base of huc vma
527  *
528  * Triggers a HuC firmware authentication request to the GuC via intel_guc_send
529  * INTEL_GUC_ACTION_AUTHENTICATE_HUC interface. This function is invoked by
530  * intel_huc_auth().
531  *
532  * Return:	non-zero code on error
533  */
534 int intel_guc_auth_huc(struct intel_guc *guc, u32 rsa_offset)
535 {
536 	u32 action[] = {
537 		INTEL_GUC_ACTION_AUTHENTICATE_HUC,
538 		rsa_offset
539 	};
540 
541 	return intel_guc_send(guc, action, ARRAY_SIZE(action));
542 }
543 
544 /**
545  * intel_guc_suspend() - notify GuC entering suspend state
546  * @guc:	the guc
547  */
548 int intel_guc_suspend(struct intel_guc *guc)
549 {
550 	int ret;
551 	u32 action[] = {
552 		INTEL_GUC_ACTION_RESET_CLIENT,
553 	};
554 
555 	if (!intel_guc_is_ready(guc))
556 		return 0;
557 
558 	if (intel_guc_submission_is_used(guc)) {
559 		/*
560 		 * This H2G MMIO command tears down the GuC in two steps. First it will
561 		 * generate a G2H CTB for every active context indicating a reset. In
562 		 * practice the i915 shouldn't ever get a G2H as suspend should only be
563 		 * called when the GPU is idle. Next, it tears down the CTBs and this
564 		 * H2G MMIO command completes.
565 		 *
566 		 * Don't abort on a failure code from the GuC. Keep going and do the
567 		 * clean up in santize() and re-initialisation on resume and hopefully
568 		 * the error here won't be problematic.
569 		 */
570 		ret = intel_guc_send_mmio(guc, action, ARRAY_SIZE(action), NULL, 0);
571 		if (ret)
572 			DRM_ERROR("GuC suspend: RESET_CLIENT action failed with error %d!\n", ret);
573 	}
574 
575 	/* Signal that the GuC isn't running. */
576 	intel_guc_sanitize(guc);
577 
578 	return 0;
579 }
580 
581 /**
582  * intel_guc_resume() - notify GuC resuming from suspend state
583  * @guc:	the guc
584  */
585 int intel_guc_resume(struct intel_guc *guc)
586 {
587 	/*
588 	 * NB: This function can still be called even if GuC submission is
589 	 * disabled, e.g. if GuC is enabled for HuC authentication only. Thus,
590 	 * if any code is later added here, it must be support doing nothing
591 	 * if submission is disabled (as per intel_guc_suspend).
592 	 */
593 	return 0;
594 }
595 
596 /**
597  * DOC: GuC Memory Management
598  *
599  * GuC can't allocate any memory for its own usage, so all the allocations must
600  * be handled by the host driver. GuC accesses the memory via the GGTT, with the
601  * exception of the top and bottom parts of the 4GB address space, which are
602  * instead re-mapped by the GuC HW to memory location of the FW itself (WOPCM)
603  * or other parts of the HW. The driver must take care not to place objects that
604  * the GuC is going to access in these reserved ranges. The layout of the GuC
605  * address space is shown below:
606  *
607  * ::
608  *
609  *     +===========> +====================+ <== FFFF_FFFF
610  *     ^             |      Reserved      |
611  *     |             +====================+ <== GUC_GGTT_TOP
612  *     |             |                    |
613  *     |             |        DRAM        |
614  *    GuC            |                    |
615  *  Address    +===> +====================+ <== GuC ggtt_pin_bias
616  *   Space     ^     |                    |
617  *     |       |     |                    |
618  *     |      GuC    |        GuC         |
619  *     |     WOPCM   |       WOPCM        |
620  *     |      Size   |                    |
621  *     |       |     |                    |
622  *     v       v     |                    |
623  *     +=======+===> +====================+ <== 0000_0000
624  *
625  * The lower part of GuC Address Space [0, ggtt_pin_bias) is mapped to GuC WOPCM
626  * while upper part of GuC Address Space [ggtt_pin_bias, GUC_GGTT_TOP) is mapped
627  * to DRAM. The value of the GuC ggtt_pin_bias is the GuC WOPCM size.
628  */
629 
630 /**
631  * intel_guc_allocate_vma() - Allocate a GGTT VMA for GuC usage
632  * @guc:	the guc
633  * @size:	size of area to allocate (both virtual space and memory)
634  *
635  * This is a wrapper to create an object for use with the GuC. In order to
636  * use it inside the GuC, an object needs to be pinned lifetime, so we allocate
637  * both some backing storage and a range inside the Global GTT. We must pin
638  * it in the GGTT somewhere other than than [0, GUC ggtt_pin_bias) because that
639  * range is reserved inside GuC.
640  *
641  * Return:	A i915_vma if successful, otherwise an ERR_PTR.
642  */
643 struct i915_vma *intel_guc_allocate_vma(struct intel_guc *guc, u32 size)
644 {
645 	struct intel_gt *gt = guc_to_gt(guc);
646 	struct drm_i915_gem_object *obj;
647 	struct i915_vma *vma;
648 	u64 flags;
649 	int ret;
650 
651 	if (HAS_LMEM(gt->i915))
652 		obj = i915_gem_object_create_lmem(gt->i915, size,
653 						  I915_BO_ALLOC_CPU_CLEAR |
654 						  I915_BO_ALLOC_CONTIGUOUS |
655 						  I915_BO_ALLOC_PM_EARLY);
656 	else
657 		obj = i915_gem_object_create_shmem(gt->i915, size);
658 
659 	if (IS_ERR(obj))
660 		return ERR_CAST(obj);
661 
662 	vma = i915_vma_instance(obj, &gt->ggtt->vm, NULL);
663 	if (IS_ERR(vma))
664 		goto err;
665 
666 	flags = PIN_OFFSET_BIAS | i915_ggtt_pin_bias(vma);
667 	ret = i915_ggtt_pin(vma, NULL, 0, flags);
668 	if (ret) {
669 		vma = ERR_PTR(ret);
670 		goto err;
671 	}
672 
673 	return i915_vma_make_unshrinkable(vma);
674 
675 err:
676 	i915_gem_object_put(obj);
677 	return vma;
678 }
679 
680 /**
681  * intel_guc_allocate_and_map_vma() - Allocate and map VMA for GuC usage
682  * @guc:	the guc
683  * @size:	size of area to allocate (both virtual space and memory)
684  * @out_vma:	return variable for the allocated vma pointer
685  * @out_vaddr:	return variable for the obj mapping
686  *
687  * This wrapper calls intel_guc_allocate_vma() and then maps the allocated
688  * object with I915_MAP_WB.
689  *
690  * Return:	0 if successful, a negative errno code otherwise.
691  */
692 int intel_guc_allocate_and_map_vma(struct intel_guc *guc, u32 size,
693 				   struct i915_vma **out_vma, void **out_vaddr)
694 {
695 	struct i915_vma *vma;
696 	void *vaddr;
697 
698 	vma = intel_guc_allocate_vma(guc, size);
699 	if (IS_ERR(vma))
700 		return PTR_ERR(vma);
701 
702 	vaddr = i915_gem_object_pin_map_unlocked(vma->obj,
703 						 i915_coherent_map_type(guc_to_gt(guc)->i915,
704 									vma->obj, true));
705 	if (IS_ERR(vaddr)) {
706 		i915_vma_unpin_and_release(&vma, 0);
707 		return PTR_ERR(vaddr);
708 	}
709 
710 	*out_vma = vma;
711 	*out_vaddr = vaddr;
712 
713 	return 0;
714 }
715 
716 /**
717  * intel_guc_load_status - dump information about GuC load status
718  * @guc: the GuC
719  * @p: the &drm_printer
720  *
721  * Pretty printer for GuC load status.
722  */
723 void intel_guc_load_status(struct intel_guc *guc, struct drm_printer *p)
724 {
725 	struct intel_gt *gt = guc_to_gt(guc);
726 	struct intel_uncore *uncore = gt->uncore;
727 	intel_wakeref_t wakeref;
728 
729 	if (!intel_guc_is_supported(guc)) {
730 		drm_printf(p, "GuC not supported\n");
731 		return;
732 	}
733 
734 	if (!intel_guc_is_wanted(guc)) {
735 		drm_printf(p, "GuC disabled\n");
736 		return;
737 	}
738 
739 	intel_uc_fw_dump(&guc->fw, p);
740 
741 	with_intel_runtime_pm(uncore->rpm, wakeref) {
742 		u32 status = intel_uncore_read(uncore, GUC_STATUS);
743 		u32 i;
744 
745 		drm_printf(p, "\nGuC status 0x%08x:\n", status);
746 		drm_printf(p, "\tBootrom status = 0x%x\n",
747 			   (status & GS_BOOTROM_MASK) >> GS_BOOTROM_SHIFT);
748 		drm_printf(p, "\tuKernel status = 0x%x\n",
749 			   (status & GS_UKERNEL_MASK) >> GS_UKERNEL_SHIFT);
750 		drm_printf(p, "\tMIA Core status = 0x%x\n",
751 			   (status & GS_MIA_MASK) >> GS_MIA_SHIFT);
752 		drm_puts(p, "\nScratch registers:\n");
753 		for (i = 0; i < 16; i++) {
754 			drm_printf(p, "\t%2d: \t0x%x\n",
755 				   i, intel_uncore_read(uncore, SOFT_SCRATCH(i)));
756 		}
757 	}
758 }
759 
760 void intel_guc_write_barrier(struct intel_guc *guc)
761 {
762 	struct intel_gt *gt = guc_to_gt(guc);
763 
764 	if (i915_gem_object_is_lmem(guc->ct.vma->obj)) {
765 		/*
766 		 * Ensure intel_uncore_write_fw can be used rather than
767 		 * intel_uncore_write.
768 		 */
769 		GEM_BUG_ON(guc->send_regs.fw_domains);
770 
771 		/*
772 		 * This register is used by the i915 and GuC for MMIO based
773 		 * communication. Once we are in this code CTBs are the only
774 		 * method the i915 uses to communicate with the GuC so it is
775 		 * safe to write to this register (a value of 0 is NOP for MMIO
776 		 * communication). If we ever start mixing CTBs and MMIOs a new
777 		 * register will have to be chosen. This function is also used
778 		 * to enforce ordering of a work queue item write and an update
779 		 * to the process descriptor. When a work queue is being used,
780 		 * CTBs are also the only mechanism of communication.
781 		 */
782 		intel_uncore_write_fw(gt->uncore, GEN11_SOFT_SCRATCH(0), 0);
783 	} else {
784 		/* wmb() sufficient for a barrier if in smem */
785 		wmb();
786 	}
787 }
788