summaryrefslogtreecommitdiff
path: root/drivers/gpu/drm/i915/intel_guc.c
blob: 116f4ccf1bbd62b515350c19c28ec86ae99b62a8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
/*
 * Copyright © 2014-2017 Intel Corporation
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 *
 */

#include "intel_guc.h"
#include "intel_guc_ads.h"
#include "intel_guc_submission.h"
#include "i915_drv.h"

static void gen8_guc_raise_irq(struct intel_guc *guc)
{
	struct drm_i915_private *dev_priv = guc_to_i915(guc);

	I915_WRITE(GUC_SEND_INTERRUPT, GUC_SEND_TRIGGER);
}

static inline i915_reg_t guc_send_reg(struct intel_guc *guc, u32 i)
{
	GEM_BUG_ON(!guc->send_regs.base);
	GEM_BUG_ON(!guc->send_regs.count);
	GEM_BUG_ON(i >= guc->send_regs.count);

	return _MMIO(guc->send_regs.base + 4 * i);
}

void intel_guc_init_send_regs(struct intel_guc *guc)
{
	struct drm_i915_private *dev_priv = guc_to_i915(guc);
	enum forcewake_domains fw_domains = 0;
	unsigned int i;

	guc->send_regs.base = i915_mmio_reg_offset(SOFT_SCRATCH(0));
	guc->send_regs.count = SOFT_SCRATCH_COUNT - 1;

	for (i = 0; i < guc->send_regs.count; i++) {
		fw_domains |= intel_uncore_forcewake_for_reg(dev_priv,
					guc_send_reg(guc, i),
					FW_REG_READ | FW_REG_WRITE);
	}
	guc->send_regs.fw_domains = fw_domains;
}

void intel_guc_init_early(struct intel_guc *guc)
{
	intel_guc_fw_init_early(guc);
	intel_guc_ct_init_early(&guc->ct);
	intel_guc_log_init_early(&guc->log);

	mutex_init(&guc->send_mutex);
	spin_lock_init(&guc->irq_lock);
	guc->send = intel_guc_send_nop;
	guc->handler = intel_guc_to_host_event_handler_nop;
	guc->notify = gen8_guc_raise_irq;
}

int intel_guc_init_wq(struct intel_guc *guc)
{
	struct drm_i915_private *dev_priv = guc_to_i915(guc);

	/*
	 * GuC log buffer flush work item has to do register access to
	 * send the ack to GuC and this work item, if not synced before
	 * suspend, can potentially get executed after the GFX device is
	 * suspended.
	 * By marking the WQ as freezable, we don't have to bother about
	 * flushing of this work item from the suspend hooks, the pending
	 * work item if any will be either executed before the suspend
	 * or scheduled later on resume. This way the handling of work
	 * item can be kept same between system suspend & rpm suspend.
	 */
	guc->log.relay.flush_wq =
		alloc_ordered_workqueue("i915-guc_log",
					WQ_HIGHPRI | WQ_FREEZABLE);
	if (!guc->log.relay.flush_wq) {
		DRM_ERROR("Couldn't allocate workqueue for GuC log\n");
		return -ENOMEM;
	}

	/*
	 * Even though both sending GuC action, and adding a new workitem to
	 * GuC workqueue are serialized (each with its own locking), since
	 * we're using mutliple engines, it's possible that we're going to
	 * issue a preempt request with two (or more - each for different
	 * engine) workitems in GuC queue. In this situation, GuC may submit
	 * all of them, which will make us very confused.
	 * Our preemption contexts may even already be complete - before we
	 * even had the chance to sent the preempt action to GuC!. Rather
	 * than introducing yet another lock, we can just use ordered workqueue
	 * to make sure we're always sending a single preemption request with a
	 * single workitem.
	 */
	if (HAS_LOGICAL_RING_PREEMPTION(dev_priv) &&
	    USES_GUC_SUBMISSION(dev_priv)) {
		guc->preempt_wq = alloc_ordered_workqueue("i915-guc_preempt",
							  WQ_HIGHPRI);
		if (!guc->preempt_wq) {
			destroy_workqueue(guc->log.relay.flush_wq);
			DRM_ERROR("Couldn't allocate workqueue for GuC "
				  "preemption\n");
			return -ENOMEM;
		}
	}

	return 0;
}

void intel_guc_fini_wq(struct intel_guc *guc)
{
	struct drm_i915_private *dev_priv = guc_to_i915(guc);

	if (HAS_LOGICAL_RING_PREEMPTION(dev_priv) &&
	    USES_GUC_SUBMISSION(dev_priv))
		destroy_workqueue(guc->preempt_wq);

	destroy_workqueue(guc->log.relay.flush_wq);
}

static int guc_shared_data_create(struct intel_guc *guc)
{
	struct i915_vma *vma;
	void *vaddr;

	vma = intel_guc_allocate_vma(guc, PAGE_SIZE);
	if (IS_ERR(vma))
		return PTR_ERR(vma);

	vaddr = i915_gem_object_pin_map(vma->obj, I915_MAP_WB);
	if (IS_ERR(vaddr)) {
		i915_vma_unpin_and_release(&vma);
		return PTR_ERR(vaddr);
	}

	guc->shared_data = vma;
	guc->shared_data_vaddr = vaddr;

	return 0;
}

static void guc_shared_data_destroy(struct intel_guc *guc)
{
	i915_gem_object_unpin_map(guc->shared_data->obj);
	i915_vma_unpin_and_release(&guc->shared_data);
}

int intel_guc_init(struct intel_guc *guc)
{
	struct drm_i915_private *dev_priv = guc_to_i915(guc);
	int ret;

	ret = guc_shared_data_create(guc);
	if (ret)
		return ret;
	GEM_BUG_ON(!guc->shared_data);

	ret = intel_guc_log_create(&guc->log);
	if (ret)
		goto err_shared;

	ret = intel_guc_ads_create(guc);
	if (ret)
		goto err_log;
	GEM_BUG_ON(!guc->ads_vma);

	/* We need to notify the guc whenever we change the GGTT */
	i915_ggtt_enable_guc(dev_priv);

	return 0;

err_log:
	intel_guc_log_destroy(&guc->log);
err_shared:
	guc_shared_data_destroy(guc);
	return ret;
}

void intel_guc_fini(struct intel_guc *guc)
{
	struct drm_i915_private *dev_priv = guc_to_i915(guc);

	i915_ggtt_disable_guc(dev_priv);
	intel_guc_ads_destroy(guc);
	intel_guc_log_destroy(&guc->log);
	guc_shared_data_destroy(guc);
}

static u32 get_log_control_flags(void)
{
	u32 level = i915_modparams.guc_log_level;
	u32 flags = 0;

	GEM_BUG_ON(level < 0);

	if (!GUC_LOG_LEVEL_IS_ENABLED(level))
		flags |= GUC_LOG_DEFAULT_DISABLED;

	if (!GUC_LOG_LEVEL_IS_VERBOSE(level))
		flags |= GUC_LOG_DISABLED;
	else
		flags |= GUC_LOG_LEVEL_TO_VERBOSITY(level) <<
			 GUC_LOG_VERBOSITY_SHIFT;

	return flags;
}

/*
 * Initialise the GuC parameter block before starting the firmware
 * transfer. These parameters are read by the firmware on startup
 * and cannot be changed thereafter.
 */
void intel_guc_init_params(struct intel_guc *guc)
{
	struct drm_i915_private *dev_priv = guc_to_i915(guc);
	u32 params[GUC_CTL_MAX_DWORDS];
	int i;

	memset(params, 0, sizeof(params));

	/*
	 * GuC ARAT increment is 10 ns. GuC default scheduler quantum is one
	 * second. This ARAR is calculated by:
	 * Scheduler-Quantum-in-ns / ARAT-increment-in-ns = 1000000000 / 10
	 */
	params[GUC_CTL_ARAT_HIGH] = 0;
	params[GUC_CTL_ARAT_LOW] = 100000000;

	params[GUC_CTL_WA] |= GUC_CTL_WA_UK_BY_DRIVER;

	params[GUC_CTL_FEATURE] |= GUC_CTL_DISABLE_SCHEDULER |
			GUC_CTL_VCS2_ENABLED;

	params[GUC_CTL_LOG_PARAMS] = guc->log.flags;

	params[GUC_CTL_DEBUG] = get_log_control_flags();

	/* If GuC submission is enabled, set up additional parameters here */
	if (USES_GUC_SUBMISSION(dev_priv)) {
		u32 ads = intel_guc_ggtt_offset(guc,
						guc->ads_vma) >> PAGE_SHIFT;
		u32 pgs = intel_guc_ggtt_offset(guc, guc->stage_desc_pool);
		u32 ctx_in_16 = GUC_MAX_STAGE_DESCRIPTORS / 16;

		params[GUC_CTL_DEBUG] |= ads << GUC_ADS_ADDR_SHIFT;
		params[GUC_CTL_DEBUG] |= GUC_ADS_ENABLED;

		pgs >>= PAGE_SHIFT;
		params[GUC_CTL_CTXINFO] = (pgs << GUC_CTL_BASE_ADDR_SHIFT) |
			(ctx_in_16 << GUC_CTL_CTXNUM_IN16_SHIFT);

		params[GUC_CTL_FEATURE] |= GUC_CTL_KERNEL_SUBMISSIONS;

		/* Unmask this bit to enable the GuC's internal scheduler */
		params[GUC_CTL_FEATURE] &= ~GUC_CTL_DISABLE_SCHEDULER;
	}

	/*
	 * All SOFT_SCRATCH registers are in FORCEWAKE_BLITTER domain and
	 * they are power context saved so it's ok to release forcewake
	 * when we are done here and take it again at xfer time.
	 */
	intel_uncore_forcewake_get(dev_priv, FORCEWAKE_BLITTER);

	I915_WRITE(SOFT_SCRATCH(0), 0);

	for (i = 0; i < GUC_CTL_MAX_DWORDS; i++)
		I915_WRITE(SOFT_SCRATCH(1 + i), params[i]);

	intel_uncore_forcewake_put(dev_priv, FORCEWAKE_BLITTER);
}

int intel_guc_send_nop(struct intel_guc *guc, const u32 *action, u32 len,
		       u32 *response_buf, u32 response_buf_size)
{
	WARN(1, "Unexpected send: action=%#x\n", *action);
	return -ENODEV;
}

void intel_guc_to_host_event_handler_nop(struct intel_guc *guc)
{
	WARN(1, "Unexpected event: no suitable handler\n");
}

/*
 * This function implements the MMIO based host to GuC interface.
 */
int intel_guc_send_mmio(struct intel_guc *guc, const u32 *action, u32 len,
			u32 *response_buf, u32 response_buf_size)
{
	struct drm_i915_private *dev_priv = guc_to_i915(guc);
	u32 status;
	int i;
	int ret;

	GEM_BUG_ON(!len);
	GEM_BUG_ON(len > guc->send_regs.count);

	/* We expect only action code */
	GEM_BUG_ON(*action & ~INTEL_GUC_MSG_CODE_MASK);

	/* If CT is available, we expect to use MMIO only during init/fini */
	GEM_BUG_ON(HAS_GUC_CT(dev_priv) &&
		*action != INTEL_GUC_ACTION_REGISTER_COMMAND_TRANSPORT_BUFFER &&
		*action != INTEL_GUC_ACTION_DEREGISTER_COMMAND_TRANSPORT_BUFFER);

	mutex_lock(&guc->send_mutex);
	intel_uncore_forcewake_get(dev_priv, guc->send_regs.fw_domains);

	for (i = 0; i < len; i++)
		I915_WRITE(guc_send_reg(guc, i), action[i]);

	POSTING_READ(guc_send_reg(guc, i - 1));

	intel_guc_notify(guc);

	/*
	 * No GuC command should ever take longer than 10ms.
	 * Fast commands should still complete in 10us.
	 */
	ret = __intel_wait_for_register_fw(dev_priv,
					   guc_send_reg(guc, 0),
					   INTEL_GUC_MSG_TYPE_MASK,
					   INTEL_GUC_MSG_TYPE_RESPONSE <<
					   INTEL_GUC_MSG_TYPE_SHIFT,
					   10, 10, &status);
	/* If GuC explicitly returned an error, convert it to -EIO */
	if (!ret && !INTEL_GUC_MSG_IS_RESPONSE_SUCCESS(status))
		ret = -EIO;

	if (ret) {
		DRM_DEBUG_DRIVER("INTEL_GUC_SEND: Action 0x%X failed;"
				 " ret=%d status=0x%08X response=0x%08X\n",
				 action[0], ret, status,
				 I915_READ(SOFT_SCRATCH(15)));
		goto out;
	}

	if (response_buf) {
		int count = min(response_buf_size, guc->send_regs.count - 1);

		for (i = 0; i < count; i++)
			response_buf[i] = I915_READ(guc_send_reg(guc, i + 1));
	}

	/* Use data from the GuC response as our return value */
	ret = INTEL_GUC_MSG_TO_DATA(status);

out:
	intel_uncore_forcewake_put(dev_priv, guc->send_regs.fw_domains);
	mutex_unlock(&guc->send_mutex);

	return ret;
}

void intel_guc_to_host_event_handler_mmio(struct intel_guc *guc)
{
	struct drm_i915_private *dev_priv = guc_to_i915(guc);
	u32 msg, val;

	/*
	 * Sample the log buffer flush related bits & clear them out now
	 * itself from the message identity register to minimize the
	 * probability of losing a flush interrupt, when there are back
	 * to back flush interrupts.
	 * There can be a new flush interrupt, for different log buffer
	 * type (like for ISR), whilst Host is handling one (for DPC).
	 * Since same bit is used in message register for ISR & DPC, it
	 * could happen that GuC sets the bit for 2nd interrupt but Host
	 * clears out the bit on handling the 1st interrupt.
	 */
	spin_lock(&guc->irq_lock);
	val = I915_READ(SOFT_SCRATCH(15));
	msg = val & guc->msg_enabled_mask;
	I915_WRITE(SOFT_SCRATCH(15), val & ~msg);
	spin_unlock(&guc->irq_lock);

	intel_guc_to_host_process_recv_msg(guc, msg);
}

void intel_guc_to_host_process_recv_msg(struct intel_guc *guc, u32 msg)
{
	/* Make sure to handle only enabled messages */
	msg &= guc->msg_enabled_mask;

	if (msg & (INTEL_GUC_RECV_MSG_FLUSH_LOG_BUFFER |
		   INTEL_GUC_RECV_MSG_CRASH_DUMP_POSTED))
		intel_guc_log_handle_flush_event(&guc->log);
}

int intel_guc_sample_forcewake(struct intel_guc *guc)
{
	struct drm_i915_private *dev_priv = guc_to_i915(guc);
	u32 action[2];

	action[0] = INTEL_GUC_ACTION_SAMPLE_FORCEWAKE;
	/* WaRsDisableCoarsePowerGating:skl,cnl */
	if (!HAS_RC6(dev_priv) || NEEDS_WaRsDisableCoarsePowerGating(dev_priv))
		action[1] = 0;
	else
		/* bit 0 and 1 are for Render and Media domain separately */
		action[1] = GUC_FORCEWAKE_RENDER | GUC_FORCEWAKE_MEDIA;

	return intel_guc_send(guc, action, ARRAY_SIZE(action));
}

/**
 * intel_guc_auth_huc() - Send action to GuC to authenticate HuC ucode
 * @guc: intel_guc structure
 * @rsa_offset: rsa offset w.r.t ggtt base of huc vma
 *
 * Triggers a HuC firmware authentication request to the GuC via intel_guc_send
 * INTEL_GUC_ACTION_AUTHENTICATE_HUC interface. This function is invoked by
 * intel_huc_auth().
 *
 * Return:	non-zero code on error
 */
int intel_guc_auth_huc(struct intel_guc *guc, u32 rsa_offset)
{
	u32 action[] = {
		INTEL_GUC_ACTION_AUTHENTICATE_HUC,
		rsa_offset
	};

	return intel_guc_send(guc, action, ARRAY_SIZE(action));
}

/**
 * intel_guc_suspend() - notify GuC entering suspend state
 * @guc:	the guc
 */
int intel_guc_suspend(struct intel_guc *guc)
{
	u32 data[] = {
		INTEL_GUC_ACTION_ENTER_S_STATE,
		GUC_POWER_D1, /* any value greater than GUC_POWER_D0 */
		intel_guc_ggtt_offset(guc, guc->shared_data)
	};

	return intel_guc_send(guc, data, ARRAY_SIZE(data));
}

/**
 * intel_guc_reset_engine() - ask GuC to reset an engine
 * @guc:	intel_guc structure
 * @engine:	engine to be reset
 */
int intel_guc_reset_engine(struct intel_guc *guc,
			   struct intel_engine_cs *engine)
{
	u32 data[7];

	GEM_BUG_ON(!guc->execbuf_client);

	data[0] = INTEL_GUC_ACTION_REQUEST_ENGINE_RESET;
	data[1] = engine->guc_id;
	data[2] = 0;
	data[3] = 0;
	data[4] = 0;
	data[5] = guc->execbuf_client->stage_id;
	data[6] = intel_guc_ggtt_offset(guc, guc->shared_data);

	return intel_guc_send(guc, data, ARRAY_SIZE(data));
}

/**
 * intel_guc_resume() - notify GuC resuming from suspend state
 * @guc:	the guc
 */
int intel_guc_resume(struct intel_guc *guc)
{
	u32 data[] = {
		INTEL_GUC_ACTION_EXIT_S_STATE,
		GUC_POWER_D0,
		intel_guc_ggtt_offset(guc, guc->shared_data)
	};

	return intel_guc_send(guc, data, ARRAY_SIZE(data));
}

/**
 * DOC: GuC Address Space
 *
 * The layout of GuC address space is shown below:
 *
 * ::
 *
 *     +==============> +====================+ <== GUC_GGTT_TOP
 *     ^                |                    |
 *     |                |                    |
 *     |                |        DRAM        |
 *     |                |       Memory       |
 *     |                |                    |
 *    GuC               |                    |
 *  Address  +========> +====================+ <== WOPCM Top
 *   Space   ^          |   HW contexts RSVD |
 *     |     |          |        WOPCM       |
 *     |     |     +==> +--------------------+ <== GuC WOPCM Top
 *     |    GuC    ^    |                    |
 *     |    GGTT   |    |                    |
 *     |    Pin   GuC   |        GuC         |
 *     |    Bias WOPCM  |       WOPCM        |
 *     |     |    Size  |                    |
 *     |     |     |    |                    |
 *     v     v     v    |                    |
 *     +=====+=====+==> +====================+ <== GuC WOPCM Base
 *                      |   Non-GuC WOPCM    |
 *                      |   (HuC/Reserved)   |
 *                      +====================+ <== WOPCM Base
 *
 * The lower part of GuC Address Space [0, ggtt_pin_bias) is mapped to WOPCM
 * while upper part of GuC Address Space [ggtt_pin_bias, GUC_GGTT_TOP) is mapped
 * to DRAM. The value of the GuC ggtt_pin_bias is determined by WOPCM size and
 * actual GuC WOPCM size.
 */

/**
 * intel_guc_init_ggtt_pin_bias() - Initialize the GuC ggtt_pin_bias value.
 * @guc: intel_guc structure.
 *
 * This function will calculate and initialize the ggtt_pin_bias value based on
 * overall WOPCM size and GuC WOPCM size.
 */
void intel_guc_init_ggtt_pin_bias(struct intel_guc *guc)
{
	struct drm_i915_private *i915 = guc_to_i915(guc);

	GEM_BUG_ON(!i915->wopcm.size);
	GEM_BUG_ON(i915->wopcm.size < i915->wopcm.guc.base);

	guc->ggtt_pin_bias = i915->wopcm.size - i915->wopcm.guc.base;
}

/**
 * intel_guc_allocate_vma() - Allocate a GGTT VMA for GuC usage
 * @guc:	the guc
 * @size:	size of area to allocate (both virtual space and memory)
 *
 * This is a wrapper to create an object for use with the GuC. In order to
 * use it inside the GuC, an object needs to be pinned lifetime, so we allocate
 * both some backing storage and a range inside the Global GTT. We must pin
 * it in the GGTT somewhere other than than [0, GUC ggtt_pin_bias) because that
 * range is reserved inside GuC.
 *
 * Return:	A i915_vma if successful, otherwise an ERR_PTR.
 */
struct i915_vma *intel_guc_allocate_vma(struct intel_guc *guc, u32 size)
{
	struct drm_i915_private *dev_priv = guc_to_i915(guc);
	struct drm_i915_gem_object *obj;
	struct i915_vma *vma;
	int ret;

	obj = i915_gem_object_create(dev_priv, size);
	if (IS_ERR(obj))
		return ERR_CAST(obj);

	vma = i915_vma_instance(obj, &dev_priv->ggtt.base, NULL);
	if (IS_ERR(vma))
		goto err;

	ret = i915_vma_pin(vma, 0, PAGE_SIZE,
			   PIN_GLOBAL | PIN_OFFSET_BIAS | guc->ggtt_pin_bias);
	if (ret) {
		vma = ERR_PTR(ret);
		goto err;
	}

	return vma;

err:
	i915_gem_object_put(obj);
	return vma;
}