aboutsummaryrefslogtreecommitdiff
path: root/drivers/misc/mei/hw-me.c
blob: 6a2d272cea43fe5f1cdfd3dbb4a7ed9550d3a06c (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
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
/*
 *
 * Intel Management Engine Interface (Intel MEI) Linux driver
 * Copyright (c) 2003-2012, Intel Corporation.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 */

#include <linux/pci.h>

#include <linux/kthread.h>
#include <linux/interrupt.h>

#include "mei_dev.h"
#include "hbm.h"

#include "hw-me.h"
#include "hw-me-regs.h"

/**
 * mei_me_reg_read - Reads 32bit data from the mei device
 *
 * @dev: the device structure
 * @offset: offset from which to read the data
 *
 * returns register value (u32)
 */
static inline u32 mei_me_reg_read(const struct mei_me_hw *hw,
			       unsigned long offset)
{
	return ioread32(hw->mem_addr + offset);
}


/**
 * mei_me_reg_write - Writes 32bit data to the mei device
 *
 * @dev: the device structure
 * @offset: offset from which to write the data
 * @value: register value to write (u32)
 */
static inline void mei_me_reg_write(const struct mei_me_hw *hw,
				 unsigned long offset, u32 value)
{
	iowrite32(value, hw->mem_addr + offset);
}

/**
 * mei_me_mecbrw_read - Reads 32bit data from ME circular buffer
 *  read window register
 *
 * @dev: the device structure
 *
 * returns ME_CB_RW register value (u32)
 */
static u32 mei_me_mecbrw_read(const struct mei_device *dev)
{
	return mei_me_reg_read(to_me_hw(dev), ME_CB_RW);
}
/**
 * mei_me_mecsr_read - Reads 32bit data from the ME CSR
 *
 * @dev: the device structure
 *
 * returns ME_CSR_HA register value (u32)
 */
static inline u32 mei_me_mecsr_read(const struct mei_me_hw *hw)
{
	return mei_me_reg_read(hw, ME_CSR_HA);
}

/**
 * mei_hcsr_read - Reads 32bit data from the host CSR
 *
 * @dev: the device structure
 *
 * returns H_CSR register value (u32)
 */
static inline u32 mei_hcsr_read(const struct mei_me_hw *hw)
{
	return mei_me_reg_read(hw, H_CSR);
}

/**
 * mei_hcsr_set - writes H_CSR register to the mei device,
 * and ignores the H_IS bit for it is write-one-to-zero.
 *
 * @dev: the device structure
 */
static inline void mei_hcsr_set(struct mei_me_hw *hw, u32 hcsr)
{
	hcsr &= ~H_IS;
	mei_me_reg_write(hw, H_CSR, hcsr);
}


/**
 * mei_me_hw_config - configure hw dependent settings
 *
 * @dev: mei device
 */
static void mei_me_hw_config(struct mei_device *dev)
{
	struct mei_me_hw *hw = to_me_hw(dev);
	u32 hcsr = mei_hcsr_read(to_me_hw(dev));
	/* Doesn't change in runtime */
	dev->hbuf_depth = (hcsr & H_CBD) >> 24;

	hw->pg_state = MEI_PG_OFF;
}

/**
 * mei_me_pg_state  - translate internal pg state
 *   to the mei power gating state
 *
 * @hw -  me hardware
 * returns: MEI_PG_OFF if aliveness is on and MEI_PG_ON otherwise
 */
static inline enum mei_pg_state mei_me_pg_state(struct mei_device *dev)
{
	struct mei_me_hw *hw = to_me_hw(dev);
	return hw->pg_state;
}

/**
 * mei_clear_interrupts - clear and stop interrupts
 *
 * @dev: the device structure
 */
static void mei_me_intr_clear(struct mei_device *dev)
{
	struct mei_me_hw *hw = to_me_hw(dev);
	u32 hcsr = mei_hcsr_read(hw);
	if ((hcsr & H_IS) == H_IS)
		mei_me_reg_write(hw, H_CSR, hcsr);
}
/**
 * mei_me_intr_enable - enables mei device interrupts
 *
 * @dev: the device structure
 */
static void mei_me_intr_enable(struct mei_device *dev)
{
	struct mei_me_hw *hw = to_me_hw(dev);
	u32 hcsr = mei_hcsr_read(hw);
	hcsr |= H_IE;
	mei_hcsr_set(hw, hcsr);
}

/**
 * mei_disable_interrupts - disables mei device interrupts
 *
 * @dev: the device structure
 */
static void mei_me_intr_disable(struct mei_device *dev)
{
	struct mei_me_hw *hw = to_me_hw(dev);
	u32 hcsr = mei_hcsr_read(hw);
	hcsr  &= ~H_IE;
	mei_hcsr_set(hw, hcsr);
}

/**
 * mei_me_hw_reset_release - release device from the reset
 *
 * @dev: the device structure
 */
static void mei_me_hw_reset_release(struct mei_device *dev)
{
	struct mei_me_hw *hw = to_me_hw(dev);
	u32 hcsr = mei_hcsr_read(hw);

	hcsr |= H_IG;
	hcsr &= ~H_RST;
	mei_hcsr_set(hw, hcsr);

	/* complete this write before we set host ready on another CPU */
	mmiowb();
}
/**
 * mei_me_hw_reset - resets fw via mei csr register.
 *
 * @dev: the device structure
 * @intr_enable: if interrupt should be enabled after reset.
 */
static int mei_me_hw_reset(struct mei_device *dev, bool intr_enable)
{
	struct mei_me_hw *hw = to_me_hw(dev);
	u32 hcsr = mei_hcsr_read(hw);

	hcsr |= H_RST | H_IG | H_IS;

	if (intr_enable)
		hcsr |= H_IE;
	else
		hcsr &= ~H_IE;

	dev->recvd_hw_ready = false;
	mei_me_reg_write(hw, H_CSR, hcsr);

	/*
	 * Host reads the H_CSR once to ensure that the
	 * posted write to H_CSR completes.
	 */
	hcsr = mei_hcsr_read(hw);

	if ((hcsr & H_RST) == 0)
		dev_warn(&dev->pdev->dev, "H_RST is not set = 0x%08X", hcsr);

	if ((hcsr & H_RDY) == H_RDY)
		dev_warn(&dev->pdev->dev, "H_RDY is not cleared 0x%08X", hcsr);

	if (intr_enable == false)
		mei_me_hw_reset_release(dev);

	return 0;
}

/**
 * mei_me_host_set_ready - enable device
 *
 * @dev - mei device
 * returns bool
 */

static void mei_me_host_set_ready(struct mei_device *dev)
{
	struct mei_me_hw *hw = to_me_hw(dev);
	hw->host_hw_state = mei_hcsr_read(hw);
	hw->host_hw_state |= H_IE | H_IG | H_RDY;
	mei_hcsr_set(hw, hw->host_hw_state);
}
/**
 * mei_me_host_is_ready - check whether the host has turned ready
 *
 * @dev - mei device
 * returns bool
 */
static bool mei_me_host_is_ready(struct mei_device *dev)
{
	struct mei_me_hw *hw = to_me_hw(dev);
	hw->host_hw_state = mei_hcsr_read(hw);
	return (hw->host_hw_state & H_RDY) == H_RDY;
}

/**
 * mei_me_hw_is_ready - check whether the me(hw) has turned ready
 *
 * @dev - mei device
 * returns bool
 */
static bool mei_me_hw_is_ready(struct mei_device *dev)
{
	struct mei_me_hw *hw = to_me_hw(dev);
	hw->me_hw_state = mei_me_mecsr_read(hw);
	return (hw->me_hw_state & ME_RDY_HRA) == ME_RDY_HRA;
}

static int mei_me_hw_ready_wait(struct mei_device *dev)
{
	int err;

	mutex_unlock(&dev->device_lock);
	err = wait_event_interruptible_timeout(dev->wait_hw_ready,
			dev->recvd_hw_ready,
			mei_secs_to_jiffies(MEI_HW_READY_TIMEOUT));
	mutex_lock(&dev->device_lock);
	if (!err && !dev->recvd_hw_ready) {
		if (!err)
			err = -ETIME;
		dev_err(&dev->pdev->dev,
			"wait hw ready failed. status = %d\n", err);
		return err;
	}

	dev->recvd_hw_ready = false;
	return 0;
}

static int mei_me_hw_start(struct mei_device *dev)
{
	int ret = mei_me_hw_ready_wait(dev);
	if (ret)
		return ret;
	dev_dbg(&dev->pdev->dev, "hw is ready\n");

	mei_me_host_set_ready(dev);
	return ret;
}


/**
 * mei_hbuf_filled_slots - gets number of device filled buffer slots
 *
 * @dev: the device structure
 *
 * returns number of filled slots
 */
static unsigned char mei_hbuf_filled_slots(struct mei_device *dev)
{
	struct mei_me_hw *hw = to_me_hw(dev);
	char read_ptr, write_ptr;

	hw->host_hw_state = mei_hcsr_read(hw);

	read_ptr = (char) ((hw->host_hw_state & H_CBRP) >> 8);
	write_ptr = (char) ((hw->host_hw_state & H_CBWP) >> 16);

	return (unsigned char) (write_ptr - read_ptr);
}

/**
 * mei_me_hbuf_is_empty - checks if host buffer is empty.
 *
 * @dev: the device structure
 *
 * returns true if empty, false - otherwise.
 */
static bool mei_me_hbuf_is_empty(struct mei_device *dev)
{
	return mei_hbuf_filled_slots(dev) == 0;
}

/**
 * mei_me_hbuf_empty_slots - counts write empty slots.
 *
 * @dev: the device structure
 *
 * returns -EOVERFLOW if overflow, otherwise empty slots count
 */
static int mei_me_hbuf_empty_slots(struct mei_device *dev)
{
	unsigned char filled_slots, empty_slots;

	filled_slots = mei_hbuf_filled_slots(dev);
	empty_slots = dev->hbuf_depth - filled_slots;

	/* check for overflow */
	if (filled_slots > dev->hbuf_depth)
		return -EOVERFLOW;

	return empty_slots;
}

static size_t mei_me_hbuf_max_len(const struct mei_device *dev)
{
	return dev->hbuf_depth * sizeof(u32) - sizeof(struct mei_msg_hdr);
}


/**
 * mei_me_write_message - writes a message to mei device.
 *
 * @dev: the device structure
 * @header: mei HECI header of message
 * @buf: message payload will be written
 *
 * This function returns -EIO if write has failed
 */
static int mei_me_write_message(struct mei_device *dev,
			struct mei_msg_hdr *header,
			unsigned char *buf)
{
	struct mei_me_hw *hw = to_me_hw(dev);
	unsigned long rem;
	unsigned long length = header->length;
	u32 *reg_buf = (u32 *)buf;
	u32 hcsr;
	u32 dw_cnt;
	int i;
	int empty_slots;

	dev_dbg(&dev->pdev->dev, MEI_HDR_FMT, MEI_HDR_PRM(header));

	empty_slots = mei_hbuf_empty_slots(dev);
	dev_dbg(&dev->pdev->dev, "empty slots = %hu.\n", empty_slots);

	dw_cnt = mei_data2slots(length);
	if (empty_slots < 0 || dw_cnt > empty_slots)
		return -EMSGSIZE;

	mei_me_reg_write(hw, H_CB_WW, *((u32 *) header));

	for (i = 0; i < length / 4; i++)
		mei_me_reg_write(hw, H_CB_WW, reg_buf[i]);

	rem = length & 0x3;
	if (rem > 0) {
		u32 reg = 0;
		memcpy(&reg, &buf[length - rem], rem);
		mei_me_reg_write(hw, H_CB_WW, reg);
	}

	hcsr = mei_hcsr_read(hw) | H_IG;
	mei_hcsr_set(hw, hcsr);
	if (!mei_me_hw_is_ready(dev))
		return -EIO;

	return 0;
}

/**
 * mei_me_count_full_read_slots - counts read full slots.
 *
 * @dev: the device structure
 *
 * returns -EOVERFLOW if overflow, otherwise filled slots count
 */
static int mei_me_count_full_read_slots(struct mei_device *dev)
{
	struct mei_me_hw *hw = to_me_hw(dev);
	char read_ptr, write_ptr;
	unsigned char buffer_depth, filled_slots;

	hw->me_hw_state = mei_me_mecsr_read(hw);
	buffer_depth = (unsigned char)((hw->me_hw_state & ME_CBD_HRA) >> 24);
	read_ptr = (char) ((hw->me_hw_state & ME_CBRP_HRA) >> 8);
	write_ptr = (char) ((hw->me_hw_state & ME_CBWP_HRA) >> 16);
	filled_slots = (unsigned char) (write_ptr - read_ptr);

	/* check for overflow */
	if (filled_slots > buffer_depth)
		return -EOVERFLOW;

	dev_dbg(&dev->pdev->dev, "filled_slots =%08x\n", filled_slots);
	return (int)filled_slots;
}

/**
 * mei_me_read_slots - reads a message from mei device.
 *
 * @dev: the device structure
 * @buffer: message buffer will be written
 * @buffer_length: message size will be read
 */
static int mei_me_read_slots(struct mei_device *dev, unsigned char *buffer,
		    unsigned long buffer_length)
{
	struct mei_me_hw *hw = to_me_hw(dev);
	u32 *reg_buf = (u32 *)buffer;
	u32 hcsr;

	for (; buffer_length >= sizeof(u32); buffer_length -= sizeof(u32))
		*reg_buf++ = mei_me_mecbrw_read(dev);

	if (buffer_length > 0) {
		u32 reg = mei_me_mecbrw_read(dev);
		memcpy(reg_buf, &reg, buffer_length);
	}

	hcsr = mei_hcsr_read(hw) | H_IG;
	mei_hcsr_set(hw, hcsr);
	return 0;
}

/**
 * mei_me_pg_enter - write pg enter register to mei device.
 *
 * @dev: the device structure
 */
static void mei_me_pg_enter(struct mei_device *dev)
{
	struct mei_me_hw *hw = to_me_hw(dev);
	u32 reg = mei_me_reg_read(hw, H_HPG_CSR);
	reg |= H_HPG_CSR_PGI;
	mei_me_reg_write(hw, H_HPG_CSR, reg);
}

/**
 * mei_me_pg_enter - write pg enter register to mei device.
 *
 * @dev: the device structure
 */
static void mei_me_pg_exit(struct mei_device *dev)
{
	struct mei_me_hw *hw = to_me_hw(dev);
	u32 reg = mei_me_reg_read(hw, H_HPG_CSR);

	WARN(!(reg & H_HPG_CSR_PGI), "PGI is not set\n");

	reg |= H_HPG_CSR_PGIHEXR;
	mei_me_reg_write(hw, H_HPG_CSR, reg);
}

/**
 * mei_me_pg_set_sync - perform pg entry procedure
 *
 * @dev: the device structure
 *
 * returns 0 on success an error code otherwise
 */
int mei_me_pg_set_sync(struct mei_device *dev)
{
	struct mei_me_hw *hw = to_me_hw(dev);
	unsigned long timeout = mei_secs_to_jiffies(MEI_PGI_TIMEOUT);
	int ret;

	dev->pg_event = MEI_PG_EVENT_WAIT;

	ret = mei_hbm_pg(dev, MEI_PG_ISOLATION_ENTRY_REQ_CMD);
	if (ret)
		return ret;

	mutex_unlock(&dev->device_lock);
	wait_event_timeout(dev->wait_pg,
		dev->pg_event == MEI_PG_EVENT_RECEIVED, timeout);
	mutex_lock(&dev->device_lock);

	if (dev->pg_event == MEI_PG_EVENT_RECEIVED) {
		mei_me_pg_enter(dev);
		ret = 0;
	} else {
		ret = -ETIME;
	}

	dev->pg_event = MEI_PG_EVENT_IDLE;
	hw->pg_state = MEI_PG_ON;

	return ret;
}

/**
 * mei_me_pg_unset_sync - perform pg exit procedure
 *
 * @dev: the device structure
 *
 * returns 0 on success an error code otherwise
 */
int mei_me_pg_unset_sync(struct mei_device *dev)
{
	struct mei_me_hw *hw = to_me_hw(dev);
	unsigned long timeout = mei_secs_to_jiffies(MEI_PGI_TIMEOUT);
	int ret;

	if (dev->pg_event == MEI_PG_EVENT_RECEIVED)
		goto reply;

	dev->pg_event = MEI_PG_EVENT_WAIT;

	mei_me_pg_exit(dev);

	mutex_unlock(&dev->device_lock);
	wait_event_timeout(dev->wait_pg,
		dev->pg_event == MEI_PG_EVENT_RECEIVED, timeout);
	mutex_lock(&dev->device_lock);

reply:
	if (dev->pg_event == MEI_PG_EVENT_RECEIVED)
		ret = mei_hbm_pg(dev, MEI_PG_ISOLATION_EXIT_RES_CMD);
	else
		ret = -ETIME;

	dev->pg_event = MEI_PG_EVENT_IDLE;
	hw->pg_state = MEI_PG_OFF;

	return ret;
}

/**
 * mei_me_pg_is_enabled - detect if PG is supported by HW
 *
 * @dev: the device structure
 *
 * returns: true is pg supported, false otherwise
 */
static bool mei_me_pg_is_enabled(struct mei_device *dev)
{
	struct mei_me_hw *hw = to_me_hw(dev);
	u32 reg = mei_me_reg_read(hw, ME_CSR_HA);

	if ((reg & ME_PGIC_HRA) == 0)
		goto notsupported;

	if (dev->version.major_version < HBM_MAJOR_VERSION_PGI)
		goto notsupported;

	if (dev->version.major_version == HBM_MAJOR_VERSION_PGI &&
	    dev->version.minor_version < HBM_MINOR_VERSION_PGI)
		goto notsupported;

	return true;

notsupported:
	dev_dbg(&dev->pdev->dev, "pg: not supported: HGP = %d hbm version %d.%d ?= %d.%d\n",
		!!(reg & ME_PGIC_HRA),
		dev->version.major_version,
		dev->version.minor_version,
		HBM_MAJOR_VERSION_PGI,
		HBM_MINOR_VERSION_PGI);

	return false;
}

/**
 * mei_me_irq_quick_handler - The ISR of the MEI device
 *
 * @irq: The irq number
 * @dev_id: pointer to the device structure
 *
 * returns irqreturn_t
 */

irqreturn_t mei_me_irq_quick_handler(int irq, void *dev_id)
{
	struct mei_device *dev = (struct mei_device *) dev_id;
	struct mei_me_hw *hw = to_me_hw(dev);
	u32 csr_reg = mei_hcsr_read(hw);

	if ((csr_reg & H_IS) != H_IS)
		return IRQ_NONE;

	/* clear H_IS bit in H_CSR */
	mei_me_reg_write(hw, H_CSR, csr_reg);

	return IRQ_WAKE_THREAD;
}

/**
 * mei_me_irq_thread_handler - function called after ISR to handle the interrupt
 * processing.
 *
 * @irq: The irq number
 * @dev_id: pointer to the device structure
 *
 * returns irqreturn_t
 *
 */
irqreturn_t mei_me_irq_thread_handler(int irq, void *dev_id)
{
	struct mei_device *dev = (struct mei_device *) dev_id;
	struct mei_cl_cb complete_list;
	s32 slots;
	int rets = 0;

	dev_dbg(&dev->pdev->dev, "function called after ISR to handle the interrupt processing.\n");
	/* initialize our complete list */
	mutex_lock(&dev->device_lock);
	mei_io_list_init(&complete_list);

	/* Ack the interrupt here
	 * In case of MSI we don't go through the quick handler */
	if (pci_dev_msi_enabled(dev->pdev))
		mei_clear_interrupts(dev);

	/* check if ME wants a reset */
	if (!mei_hw_is_ready(dev) && dev->dev_state != MEI_DEV_RESETTING) {
		dev_warn(&dev->pdev->dev, "FW not ready: resetting.\n");
		schedule_work(&dev->reset_work);
		goto end;
	}

	/*  check if we need to start the dev */
	if (!mei_host_is_ready(dev)) {
		if (mei_hw_is_ready(dev)) {
			mei_me_hw_reset_release(dev);
			dev_dbg(&dev->pdev->dev, "we need to start the dev.\n");

			dev->recvd_hw_ready = true;
			wake_up_interruptible(&dev->wait_hw_ready);
		} else {
			dev_dbg(&dev->pdev->dev, "Spurious Interrupt\n");
		}
		goto end;
	}
	/* check slots available for reading */
	slots = mei_count_full_read_slots(dev);
	while (slots > 0) {
		dev_dbg(&dev->pdev->dev, "slots to read = %08x\n", slots);
		rets = mei_irq_read_handler(dev, &complete_list, &slots);
		/* There is a race between ME write and interrupt delivery:
		 * Not all data is always available immediately after the
		 * interrupt, so try to read again on the next interrupt.
		 */
		if (rets == -ENODATA)
			break;

		if (rets && dev->dev_state != MEI_DEV_RESETTING) {
			dev_err(&dev->pdev->dev, "mei_irq_read_handler ret = %d.\n",
						rets);
			schedule_work(&dev->reset_work);
			goto end;
		}
	}

	dev->hbuf_is_ready = mei_hbuf_is_ready(dev);

	/*
	 * During PG handshake only allowed write is the replay to the
	 * PG exit message, so block calling write function
	 * if the pg state is not idle
	 */
	if (dev->pg_event == MEI_PG_EVENT_IDLE) {
		rets = mei_irq_write_handler(dev, &complete_list);
		dev->hbuf_is_ready = mei_hbuf_is_ready(dev);
	}

	mei_irq_compl_handler(dev, &complete_list);

end:
	dev_dbg(&dev->pdev->dev, "interrupt thread end ret = %d\n", rets);
	mutex_unlock(&dev->device_lock);
	return IRQ_HANDLED;
}

/**
 * mei_me_fw_status - retrieve fw status from the pci config space
 *
 * @dev: the device structure
 * @fw_status: fw status registers storage
 *
 * returns 0 on success an error code otherwise
 */
static int mei_me_fw_status(struct mei_device *dev,
			    struct mei_fw_status *fw_status)
{
	const u32 pci_cfg_reg[] = {PCI_CFG_HFS_1, PCI_CFG_HFS_2};
	int i;

	if (!fw_status)
		return -EINVAL;

	switch (dev->pdev->device) {
	case MEI_DEV_ID_IBXPK_1:
	case MEI_DEV_ID_IBXPK_2:
	case MEI_DEV_ID_CPT_1:
	case MEI_DEV_ID_PBG_1:
	case MEI_DEV_ID_PPT_1:
	case MEI_DEV_ID_PPT_2:
	case MEI_DEV_ID_PPT_3:
	case MEI_DEV_ID_LPT_H:
	case MEI_DEV_ID_LPT_W:
	case MEI_DEV_ID_LPT_LP:
	case MEI_DEV_ID_LPT_HR:
	case MEI_DEV_ID_WPT_LP:
		fw_status->count = 2;
		break;
	case MEI_DEV_ID_ICH10_1:
	case MEI_DEV_ID_ICH10_2:
	case MEI_DEV_ID_ICH10_3:
	case MEI_DEV_ID_ICH10_4:
		fw_status->count = 1;
		break;
	default:
		fw_status->count = 0;
		break;
	}

	for (i = 0; i < fw_status->count && i < MEI_FW_STATUS_MAX; i++) {
		int ret;
		ret = pci_read_config_dword(dev->pdev,
				pci_cfg_reg[i], &fw_status->status[i]);
		if (ret)
			return ret;
	}
	return 0;
}

static const struct mei_hw_ops mei_me_hw_ops = {

	.pg_state  = mei_me_pg_state,

	.fw_status = mei_me_fw_status,
	.host_is_ready = mei_me_host_is_ready,

	.hw_is_ready = mei_me_hw_is_ready,
	.hw_reset = mei_me_hw_reset,
	.hw_config = mei_me_hw_config,
	.hw_start = mei_me_hw_start,

	.pg_is_enabled = mei_me_pg_is_enabled,

	.intr_clear = mei_me_intr_clear,
	.intr_enable = mei_me_intr_enable,
	.intr_disable = mei_me_intr_disable,

	.hbuf_free_slots = mei_me_hbuf_empty_slots,
	.hbuf_is_ready = mei_me_hbuf_is_empty,
	.hbuf_max_len = mei_me_hbuf_max_len,

	.write = mei_me_write_message,

	.rdbuf_full_slots = mei_me_count_full_read_slots,
	.read_hdr = mei_me_mecbrw_read,
	.read = mei_me_read_slots
};

static bool mei_me_fw_type_nm(struct pci_dev *pdev)
{
	u32 reg;
	pci_read_config_dword(pdev, PCI_CFG_HFS_2, &reg);
	/* make sure that bit 9 (NM) is up and bit 10 (DM) is down */
	return (reg & 0x600) == 0x200;
}

#define MEI_CFG_FW_NM                           \
	.quirk_probe = mei_me_fw_type_nm

static bool mei_me_fw_type_sps(struct pci_dev *pdev)
{
	u32 reg;
	/* Read ME FW Status check for SPS Firmware */
	pci_read_config_dword(pdev, PCI_CFG_HFS_1, &reg);
	/* if bits [19:16] = 15, running SPS Firmware */
	return (reg & 0xf0000) == 0xf0000;
}

#define MEI_CFG_FW_SPS                           \
	.quirk_probe = mei_me_fw_type_sps


#define MEI_CFG_LEGACY_HFS                      \
	.fw_status.count = 0

#define MEI_CFG_ICH_HFS                        \
	.fw_status.count = 1,                   \
	.fw_status.status[0] = PCI_CFG_HFS_1

#define MEI_CFG_PCH_HFS                         \
	.fw_status.count = 2,                   \
	.fw_status.status[0] = PCI_CFG_HFS_1,   \
	.fw_status.status[1] = PCI_CFG_HFS_2


/* ICH Legacy devices */
const struct mei_cfg mei_me_legacy_cfg = {
	MEI_CFG_LEGACY_HFS,
};

/* ICH devices */
const struct mei_cfg mei_me_ich_cfg = {
	MEI_CFG_ICH_HFS,
};

/* PCH devices */
const struct mei_cfg mei_me_pch_cfg = {
	MEI_CFG_PCH_HFS,
};


/* PCH Cougar Point and Patsburg with quirk for Node Manager exclusion */
const struct mei_cfg mei_me_pch_cpt_pbg_cfg = {
	MEI_CFG_PCH_HFS,
	MEI_CFG_FW_NM,
};

/* PCH Lynx Point with quirk for SPS Firmware exclusion */
const struct mei_cfg mei_me_lpt_cfg = {
	MEI_CFG_PCH_HFS,
	MEI_CFG_FW_SPS,
};

/**
 * mei_me_dev_init - allocates and initializes the mei device structure
 *
 * @pdev: The pci device structure
 * @cfg: per device generation config
 *
 * returns The mei_device_device pointer on success, NULL on failure.
 */
struct mei_device *mei_me_dev_init(struct pci_dev *pdev,
				   const struct mei_cfg *cfg)
{
	struct mei_device *dev;

	dev = kzalloc(sizeof(struct mei_device) +
			 sizeof(struct mei_me_hw), GFP_KERNEL);
	if (!dev)
		return NULL;

	mei_device_init(dev, cfg);

	dev->ops = &mei_me_hw_ops;

	dev->pdev = pdev;
	return dev;
}