xref: /openbmc/linux/drivers/misc/mei/hw-me.c (revision 827634ad)
1 /*
2  *
3  * Intel Management Engine Interface (Intel MEI) Linux driver
4  * Copyright (c) 2003-2012, Intel Corporation.
5  *
6  * This program is free software; you can redistribute it and/or modify it
7  * under the terms and conditions of the GNU General Public License,
8  * version 2, as published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope it will be useful, but WITHOUT
11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
13  * more details.
14  *
15  */
16 
17 #include <linux/pci.h>
18 
19 #include <linux/kthread.h>
20 #include <linux/interrupt.h>
21 
22 #include "mei_dev.h"
23 #include "hbm.h"
24 
25 #include "hw-me.h"
26 #include "hw-me-regs.h"
27 
28 #include "mei-trace.h"
29 
30 /**
31  * mei_me_reg_read - Reads 32bit data from the mei device
32  *
33  * @hw: the me hardware structure
34  * @offset: offset from which to read the data
35  *
36  * Return: register value (u32)
37  */
38 static inline u32 mei_me_reg_read(const struct mei_me_hw *hw,
39 			       unsigned long offset)
40 {
41 	return ioread32(hw->mem_addr + offset);
42 }
43 
44 
45 /**
46  * mei_me_reg_write - Writes 32bit data to the mei device
47  *
48  * @hw: the me hardware structure
49  * @offset: offset from which to write the data
50  * @value: register value to write (u32)
51  */
52 static inline void mei_me_reg_write(const struct mei_me_hw *hw,
53 				 unsigned long offset, u32 value)
54 {
55 	iowrite32(value, hw->mem_addr + offset);
56 }
57 
58 /**
59  * mei_me_mecbrw_read - Reads 32bit data from ME circular buffer
60  *  read window register
61  *
62  * @dev: the device structure
63  *
64  * Return: ME_CB_RW register value (u32)
65  */
66 static inline u32 mei_me_mecbrw_read(const struct mei_device *dev)
67 {
68 	return mei_me_reg_read(to_me_hw(dev), ME_CB_RW);
69 }
70 
71 /**
72  * mei_me_hcbww_write - write 32bit data to the host circular buffer
73  *
74  * @dev: the device structure
75  * @data: 32bit data to be written to the host circular buffer
76  */
77 static inline void mei_me_hcbww_write(struct mei_device *dev, u32 data)
78 {
79 	mei_me_reg_write(to_me_hw(dev), H_CB_WW, data);
80 }
81 
82 /**
83  * mei_me_mecsr_read - Reads 32bit data from the ME CSR
84  *
85  * @dev: the device structure
86  *
87  * Return: ME_CSR_HA register value (u32)
88  */
89 static inline u32 mei_me_mecsr_read(const struct mei_device *dev)
90 {
91 	u32 reg;
92 
93 	reg = mei_me_reg_read(to_me_hw(dev), ME_CSR_HA);
94 	trace_mei_reg_read(dev->dev, "ME_CSR_HA", ME_CSR_HA, reg);
95 
96 	return reg;
97 }
98 
99 /**
100  * mei_hcsr_read - Reads 32bit data from the host CSR
101  *
102  * @dev: the device structure
103  *
104  * Return: H_CSR register value (u32)
105  */
106 static inline u32 mei_hcsr_read(const struct mei_device *dev)
107 {
108 	u32 reg;
109 
110 	reg = mei_me_reg_read(to_me_hw(dev), H_CSR);
111 	trace_mei_reg_read(dev->dev, "H_CSR", H_CSR, reg);
112 
113 	return reg;
114 }
115 
116 /**
117  * mei_hcsr_write - writes H_CSR register to the mei device
118  *
119  * @dev: the device structure
120  * @reg: new register value
121  */
122 static inline void mei_hcsr_write(struct mei_device *dev, u32 reg)
123 {
124 	trace_mei_reg_write(dev->dev, "H_CSR", H_CSR, reg);
125 	mei_me_reg_write(to_me_hw(dev), H_CSR, reg);
126 }
127 
128 /**
129  * mei_hcsr_set - writes H_CSR register to the mei device,
130  * and ignores the H_IS bit for it is write-one-to-zero.
131  *
132  * @dev: the device structure
133  * @reg: new register value
134  */
135 static inline void mei_hcsr_set(struct mei_device *dev, u32 reg)
136 {
137 	reg &= ~H_IS;
138 	mei_hcsr_write(dev, reg);
139 }
140 
141 /**
142  * mei_me_fw_status - read fw status register from pci config space
143  *
144  * @dev: mei device
145  * @fw_status: fw status register values
146  *
147  * Return: 0 on success, error otherwise
148  */
149 static int mei_me_fw_status(struct mei_device *dev,
150 			    struct mei_fw_status *fw_status)
151 {
152 	struct pci_dev *pdev = to_pci_dev(dev->dev);
153 	struct mei_me_hw *hw = to_me_hw(dev);
154 	const struct mei_fw_status *fw_src = &hw->cfg->fw_status;
155 	int ret;
156 	int i;
157 
158 	if (!fw_status)
159 		return -EINVAL;
160 
161 	fw_status->count = fw_src->count;
162 	for (i = 0; i < fw_src->count && i < MEI_FW_STATUS_MAX; i++) {
163 		ret = pci_read_config_dword(pdev,
164 			fw_src->status[i], &fw_status->status[i]);
165 		if (ret)
166 			return ret;
167 	}
168 
169 	return 0;
170 }
171 
172 /**
173  * mei_me_hw_config - configure hw dependent settings
174  *
175  * @dev: mei device
176  */
177 static void mei_me_hw_config(struct mei_device *dev)
178 {
179 	struct mei_me_hw *hw = to_me_hw(dev);
180 	u32 hcsr = mei_hcsr_read(dev);
181 	/* Doesn't change in runtime */
182 	dev->hbuf_depth = (hcsr & H_CBD) >> 24;
183 
184 	hw->pg_state = MEI_PG_OFF;
185 }
186 
187 /**
188  * mei_me_pg_state  - translate internal pg state
189  *   to the mei power gating state
190  *
191  * @dev:  mei device
192  *
193  * Return: MEI_PG_OFF if aliveness is on and MEI_PG_ON otherwise
194  */
195 static inline enum mei_pg_state mei_me_pg_state(struct mei_device *dev)
196 {
197 	struct mei_me_hw *hw = to_me_hw(dev);
198 
199 	return hw->pg_state;
200 }
201 
202 /**
203  * mei_me_intr_clear - clear and stop interrupts
204  *
205  * @dev: the device structure
206  */
207 static void mei_me_intr_clear(struct mei_device *dev)
208 {
209 	u32 hcsr = mei_hcsr_read(dev);
210 
211 	if ((hcsr & H_IS) == H_IS)
212 		mei_hcsr_write(dev, hcsr);
213 }
214 /**
215  * mei_me_intr_enable - enables mei device interrupts
216  *
217  * @dev: the device structure
218  */
219 static void mei_me_intr_enable(struct mei_device *dev)
220 {
221 	u32 hcsr = mei_hcsr_read(dev);
222 
223 	hcsr |= H_IE;
224 	mei_hcsr_set(dev, hcsr);
225 }
226 
227 /**
228  * mei_me_intr_disable - disables mei device interrupts
229  *
230  * @dev: the device structure
231  */
232 static void mei_me_intr_disable(struct mei_device *dev)
233 {
234 	u32 hcsr = mei_hcsr_read(dev);
235 
236 	hcsr  &= ~H_IE;
237 	mei_hcsr_set(dev, hcsr);
238 }
239 
240 /**
241  * mei_me_hw_reset_release - release device from the reset
242  *
243  * @dev: the device structure
244  */
245 static void mei_me_hw_reset_release(struct mei_device *dev)
246 {
247 	u32 hcsr = mei_hcsr_read(dev);
248 
249 	hcsr |= H_IG;
250 	hcsr &= ~H_RST;
251 	mei_hcsr_set(dev, hcsr);
252 
253 	/* complete this write before we set host ready on another CPU */
254 	mmiowb();
255 }
256 /**
257  * mei_me_hw_reset - resets fw via mei csr register.
258  *
259  * @dev: the device structure
260  * @intr_enable: if interrupt should be enabled after reset.
261  *
262  * Return: always 0
263  */
264 static int mei_me_hw_reset(struct mei_device *dev, bool intr_enable)
265 {
266 	u32 hcsr = mei_hcsr_read(dev);
267 
268 	/* H_RST may be found lit before reset is started,
269 	 * for example if preceding reset flow hasn't completed.
270 	 * In that case asserting H_RST will be ignored, therefore
271 	 * we need to clean H_RST bit to start a successful reset sequence.
272 	 */
273 	if ((hcsr & H_RST) == H_RST) {
274 		dev_warn(dev->dev, "H_RST is set = 0x%08X", hcsr);
275 		hcsr &= ~H_RST;
276 		mei_hcsr_set(dev, hcsr);
277 		hcsr = mei_hcsr_read(dev);
278 	}
279 
280 	hcsr |= H_RST | H_IG | H_IS;
281 
282 	if (intr_enable)
283 		hcsr |= H_IE;
284 	else
285 		hcsr &= ~H_IE;
286 
287 	dev->recvd_hw_ready = false;
288 	mei_hcsr_write(dev, hcsr);
289 
290 	/*
291 	 * Host reads the H_CSR once to ensure that the
292 	 * posted write to H_CSR completes.
293 	 */
294 	hcsr = mei_hcsr_read(dev);
295 
296 	if ((hcsr & H_RST) == 0)
297 		dev_warn(dev->dev, "H_RST is not set = 0x%08X", hcsr);
298 
299 	if ((hcsr & H_RDY) == H_RDY)
300 		dev_warn(dev->dev, "H_RDY is not cleared 0x%08X", hcsr);
301 
302 	if (intr_enable == false)
303 		mei_me_hw_reset_release(dev);
304 
305 	return 0;
306 }
307 
308 /**
309  * mei_me_host_set_ready - enable device
310  *
311  * @dev: mei device
312  */
313 static void mei_me_host_set_ready(struct mei_device *dev)
314 {
315 	u32 hcsr = mei_hcsr_read(dev);
316 
317 	hcsr |= H_IE | H_IG | H_RDY;
318 	mei_hcsr_set(dev, hcsr);
319 }
320 
321 /**
322  * mei_me_host_is_ready - check whether the host has turned ready
323  *
324  * @dev: mei device
325  * Return: bool
326  */
327 static bool mei_me_host_is_ready(struct mei_device *dev)
328 {
329 	u32 hcsr = mei_hcsr_read(dev);
330 
331 	return (hcsr & H_RDY) == H_RDY;
332 }
333 
334 /**
335  * mei_me_hw_is_ready - check whether the me(hw) has turned ready
336  *
337  * @dev: mei device
338  * Return: bool
339  */
340 static bool mei_me_hw_is_ready(struct mei_device *dev)
341 {
342 	u32 mecsr = mei_me_mecsr_read(dev);
343 
344 	return (mecsr & ME_RDY_HRA) == ME_RDY_HRA;
345 }
346 
347 /**
348  * mei_me_hw_ready_wait - wait until the me(hw) has turned ready
349  *  or timeout is reached
350  *
351  * @dev: mei device
352  * Return: 0 on success, error otherwise
353  */
354 static int mei_me_hw_ready_wait(struct mei_device *dev)
355 {
356 	mutex_unlock(&dev->device_lock);
357 	wait_event_timeout(dev->wait_hw_ready,
358 			dev->recvd_hw_ready,
359 			mei_secs_to_jiffies(MEI_HW_READY_TIMEOUT));
360 	mutex_lock(&dev->device_lock);
361 	if (!dev->recvd_hw_ready) {
362 		dev_err(dev->dev, "wait hw ready failed\n");
363 		return -ETIME;
364 	}
365 
366 	mei_me_hw_reset_release(dev);
367 	dev->recvd_hw_ready = false;
368 	return 0;
369 }
370 
371 /**
372  * mei_me_hw_start - hw start routine
373  *
374  * @dev: mei device
375  * Return: 0 on success, error otherwise
376  */
377 static int mei_me_hw_start(struct mei_device *dev)
378 {
379 	int ret = mei_me_hw_ready_wait(dev);
380 
381 	if (ret)
382 		return ret;
383 	dev_dbg(dev->dev, "hw is ready\n");
384 
385 	mei_me_host_set_ready(dev);
386 	return ret;
387 }
388 
389 
390 /**
391  * mei_hbuf_filled_slots - gets number of device filled buffer slots
392  *
393  * @dev: the device structure
394  *
395  * Return: number of filled slots
396  */
397 static unsigned char mei_hbuf_filled_slots(struct mei_device *dev)
398 {
399 	u32 hcsr;
400 	char read_ptr, write_ptr;
401 
402 	hcsr = mei_hcsr_read(dev);
403 
404 	read_ptr = (char) ((hcsr & H_CBRP) >> 8);
405 	write_ptr = (char) ((hcsr & H_CBWP) >> 16);
406 
407 	return (unsigned char) (write_ptr - read_ptr);
408 }
409 
410 /**
411  * mei_me_hbuf_is_empty - checks if host buffer is empty.
412  *
413  * @dev: the device structure
414  *
415  * Return: true if empty, false - otherwise.
416  */
417 static bool mei_me_hbuf_is_empty(struct mei_device *dev)
418 {
419 	return mei_hbuf_filled_slots(dev) == 0;
420 }
421 
422 /**
423  * mei_me_hbuf_empty_slots - counts write empty slots.
424  *
425  * @dev: the device structure
426  *
427  * Return: -EOVERFLOW if overflow, otherwise empty slots count
428  */
429 static int mei_me_hbuf_empty_slots(struct mei_device *dev)
430 {
431 	unsigned char filled_slots, empty_slots;
432 
433 	filled_slots = mei_hbuf_filled_slots(dev);
434 	empty_slots = dev->hbuf_depth - filled_slots;
435 
436 	/* check for overflow */
437 	if (filled_slots > dev->hbuf_depth)
438 		return -EOVERFLOW;
439 
440 	return empty_slots;
441 }
442 
443 /**
444  * mei_me_hbuf_max_len - returns size of hw buffer.
445  *
446  * @dev: the device structure
447  *
448  * Return: size of hw buffer in bytes
449  */
450 static size_t mei_me_hbuf_max_len(const struct mei_device *dev)
451 {
452 	return dev->hbuf_depth * sizeof(u32) - sizeof(struct mei_msg_hdr);
453 }
454 
455 
456 /**
457  * mei_me_write_message - writes a message to mei device.
458  *
459  * @dev: the device structure
460  * @header: mei HECI header of message
461  * @buf: message payload will be written
462  *
463  * Return: -EIO if write has failed
464  */
465 static int mei_me_write_message(struct mei_device *dev,
466 			struct mei_msg_hdr *header,
467 			unsigned char *buf)
468 {
469 	unsigned long rem;
470 	unsigned long length = header->length;
471 	u32 *reg_buf = (u32 *)buf;
472 	u32 hcsr;
473 	u32 dw_cnt;
474 	int i;
475 	int empty_slots;
476 
477 	dev_dbg(dev->dev, MEI_HDR_FMT, MEI_HDR_PRM(header));
478 
479 	empty_slots = mei_hbuf_empty_slots(dev);
480 	dev_dbg(dev->dev, "empty slots = %hu.\n", empty_slots);
481 
482 	dw_cnt = mei_data2slots(length);
483 	if (empty_slots < 0 || dw_cnt > empty_slots)
484 		return -EMSGSIZE;
485 
486 	mei_me_hcbww_write(dev, *((u32 *) header));
487 
488 	for (i = 0; i < length / 4; i++)
489 		mei_me_hcbww_write(dev, reg_buf[i]);
490 
491 	rem = length & 0x3;
492 	if (rem > 0) {
493 		u32 reg = 0;
494 
495 		memcpy(&reg, &buf[length - rem], rem);
496 		mei_me_hcbww_write(dev, reg);
497 	}
498 
499 	hcsr = mei_hcsr_read(dev) | H_IG;
500 	mei_hcsr_set(dev, hcsr);
501 	if (!mei_me_hw_is_ready(dev))
502 		return -EIO;
503 
504 	return 0;
505 }
506 
507 /**
508  * mei_me_count_full_read_slots - counts read full slots.
509  *
510  * @dev: the device structure
511  *
512  * Return: -EOVERFLOW if overflow, otherwise filled slots count
513  */
514 static int mei_me_count_full_read_slots(struct mei_device *dev)
515 {
516 	u32 me_csr;
517 	char read_ptr, write_ptr;
518 	unsigned char buffer_depth, filled_slots;
519 
520 	me_csr = mei_me_mecsr_read(dev);
521 	buffer_depth = (unsigned char)((me_csr & ME_CBD_HRA) >> 24);
522 	read_ptr = (char) ((me_csr & ME_CBRP_HRA) >> 8);
523 	write_ptr = (char) ((me_csr & ME_CBWP_HRA) >> 16);
524 	filled_slots = (unsigned char) (write_ptr - read_ptr);
525 
526 	/* check for overflow */
527 	if (filled_slots > buffer_depth)
528 		return -EOVERFLOW;
529 
530 	dev_dbg(dev->dev, "filled_slots =%08x\n", filled_slots);
531 	return (int)filled_slots;
532 }
533 
534 /**
535  * mei_me_read_slots - reads a message from mei device.
536  *
537  * @dev: the device structure
538  * @buffer: message buffer will be written
539  * @buffer_length: message size will be read
540  *
541  * Return: always 0
542  */
543 static int mei_me_read_slots(struct mei_device *dev, unsigned char *buffer,
544 		    unsigned long buffer_length)
545 {
546 	u32 *reg_buf = (u32 *)buffer;
547 	u32 hcsr;
548 
549 	for (; buffer_length >= sizeof(u32); buffer_length -= sizeof(u32))
550 		*reg_buf++ = mei_me_mecbrw_read(dev);
551 
552 	if (buffer_length > 0) {
553 		u32 reg = mei_me_mecbrw_read(dev);
554 
555 		memcpy(reg_buf, &reg, buffer_length);
556 	}
557 
558 	hcsr = mei_hcsr_read(dev) | H_IG;
559 	mei_hcsr_set(dev, hcsr);
560 	return 0;
561 }
562 
563 /**
564  * mei_me_pg_set - write pg enter register
565  *
566  * @dev: the device structure
567  */
568 static void mei_me_pg_set(struct mei_device *dev)
569 {
570 	struct mei_me_hw *hw = to_me_hw(dev);
571 	u32 reg;
572 
573 	reg = mei_me_reg_read(hw, H_HPG_CSR);
574 	trace_mei_reg_read(dev->dev, "H_HPG_CSR", H_HPG_CSR, reg);
575 
576 	reg |= H_HPG_CSR_PGI;
577 
578 	trace_mei_reg_write(dev->dev, "H_HPG_CSR", H_HPG_CSR, reg);
579 	mei_me_reg_write(hw, H_HPG_CSR, reg);
580 }
581 
582 /**
583  * mei_me_pg_unset - write pg exit register
584  *
585  * @dev: the device structure
586  */
587 static void mei_me_pg_unset(struct mei_device *dev)
588 {
589 	struct mei_me_hw *hw = to_me_hw(dev);
590 	u32 reg;
591 
592 	reg = mei_me_reg_read(hw, H_HPG_CSR);
593 	trace_mei_reg_read(dev->dev, "H_HPG_CSR", H_HPG_CSR, reg);
594 
595 	WARN(!(reg & H_HPG_CSR_PGI), "PGI is not set\n");
596 
597 	reg |= H_HPG_CSR_PGIHEXR;
598 
599 	trace_mei_reg_write(dev->dev, "H_HPG_CSR", H_HPG_CSR, reg);
600 	mei_me_reg_write(hw, H_HPG_CSR, reg);
601 }
602 
603 /**
604  * mei_me_pg_enter_sync - perform pg entry procedure
605  *
606  * @dev: the device structure
607  *
608  * Return: 0 on success an error code otherwise
609  */
610 int mei_me_pg_enter_sync(struct mei_device *dev)
611 {
612 	struct mei_me_hw *hw = to_me_hw(dev);
613 	unsigned long timeout = mei_secs_to_jiffies(MEI_PGI_TIMEOUT);
614 	int ret;
615 
616 	dev->pg_event = MEI_PG_EVENT_WAIT;
617 
618 	ret = mei_hbm_pg(dev, MEI_PG_ISOLATION_ENTRY_REQ_CMD);
619 	if (ret)
620 		return ret;
621 
622 	mutex_unlock(&dev->device_lock);
623 	wait_event_timeout(dev->wait_pg,
624 		dev->pg_event == MEI_PG_EVENT_RECEIVED, timeout);
625 	mutex_lock(&dev->device_lock);
626 
627 	if (dev->pg_event == MEI_PG_EVENT_RECEIVED) {
628 		mei_me_pg_set(dev);
629 		ret = 0;
630 	} else {
631 		ret = -ETIME;
632 	}
633 
634 	dev->pg_event = MEI_PG_EVENT_IDLE;
635 	hw->pg_state = MEI_PG_ON;
636 
637 	return ret;
638 }
639 
640 /**
641  * mei_me_pg_exit_sync - perform pg exit procedure
642  *
643  * @dev: the device structure
644  *
645  * Return: 0 on success an error code otherwise
646  */
647 int mei_me_pg_exit_sync(struct mei_device *dev)
648 {
649 	struct mei_me_hw *hw = to_me_hw(dev);
650 	unsigned long timeout = mei_secs_to_jiffies(MEI_PGI_TIMEOUT);
651 	int ret;
652 
653 	if (dev->pg_event == MEI_PG_EVENT_RECEIVED)
654 		goto reply;
655 
656 	dev->pg_event = MEI_PG_EVENT_WAIT;
657 
658 	mei_me_pg_unset(dev);
659 
660 	mutex_unlock(&dev->device_lock);
661 	wait_event_timeout(dev->wait_pg,
662 		dev->pg_event == MEI_PG_EVENT_RECEIVED, timeout);
663 	mutex_lock(&dev->device_lock);
664 
665 reply:
666 	if (dev->pg_event == MEI_PG_EVENT_RECEIVED)
667 		ret = mei_hbm_pg(dev, MEI_PG_ISOLATION_EXIT_RES_CMD);
668 	else
669 		ret = -ETIME;
670 
671 	dev->pg_event = MEI_PG_EVENT_IDLE;
672 	hw->pg_state = MEI_PG_OFF;
673 
674 	return ret;
675 }
676 
677 /**
678  * mei_me_pg_is_enabled - detect if PG is supported by HW
679  *
680  * @dev: the device structure
681  *
682  * Return: true is pg supported, false otherwise
683  */
684 static bool mei_me_pg_is_enabled(struct mei_device *dev)
685 {
686 	u32 reg = mei_me_mecsr_read(dev);
687 
688 	if ((reg & ME_PGIC_HRA) == 0)
689 		goto notsupported;
690 
691 	if (!dev->hbm_f_pg_supported)
692 		goto notsupported;
693 
694 	return true;
695 
696 notsupported:
697 	dev_dbg(dev->dev, "pg: not supported: HGP = %d hbm version %d.%d ?= %d.%d\n",
698 		!!(reg & ME_PGIC_HRA),
699 		dev->version.major_version,
700 		dev->version.minor_version,
701 		HBM_MAJOR_VERSION_PGI,
702 		HBM_MINOR_VERSION_PGI);
703 
704 	return false;
705 }
706 
707 /**
708  * mei_me_irq_quick_handler - The ISR of the MEI device
709  *
710  * @irq: The irq number
711  * @dev_id: pointer to the device structure
712  *
713  * Return: irqreturn_t
714  */
715 
716 irqreturn_t mei_me_irq_quick_handler(int irq, void *dev_id)
717 {
718 	struct mei_device *dev = (struct mei_device *) dev_id;
719 	u32 hcsr = mei_hcsr_read(dev);
720 
721 	if ((hcsr & H_IS) != H_IS)
722 		return IRQ_NONE;
723 
724 	/* clear H_IS bit in H_CSR */
725 	mei_hcsr_write(dev, hcsr);
726 
727 	return IRQ_WAKE_THREAD;
728 }
729 
730 /**
731  * mei_me_irq_thread_handler - function called after ISR to handle the interrupt
732  * processing.
733  *
734  * @irq: The irq number
735  * @dev_id: pointer to the device structure
736  *
737  * Return: irqreturn_t
738  *
739  */
740 irqreturn_t mei_me_irq_thread_handler(int irq, void *dev_id)
741 {
742 	struct mei_device *dev = (struct mei_device *) dev_id;
743 	struct mei_cl_cb complete_list;
744 	s32 slots;
745 	int rets = 0;
746 
747 	dev_dbg(dev->dev, "function called after ISR to handle the interrupt processing.\n");
748 	/* initialize our complete list */
749 	mutex_lock(&dev->device_lock);
750 	mei_io_list_init(&complete_list);
751 
752 	/* Ack the interrupt here
753 	 * In case of MSI we don't go through the quick handler */
754 	if (pci_dev_msi_enabled(to_pci_dev(dev->dev)))
755 		mei_clear_interrupts(dev);
756 
757 	/* check if ME wants a reset */
758 	if (!mei_hw_is_ready(dev) && dev->dev_state != MEI_DEV_RESETTING) {
759 		dev_warn(dev->dev, "FW not ready: resetting.\n");
760 		schedule_work(&dev->reset_work);
761 		goto end;
762 	}
763 
764 	/*  check if we need to start the dev */
765 	if (!mei_host_is_ready(dev)) {
766 		if (mei_hw_is_ready(dev)) {
767 			dev_dbg(dev->dev, "we need to start the dev.\n");
768 			dev->recvd_hw_ready = true;
769 			wake_up(&dev->wait_hw_ready);
770 		} else {
771 			dev_dbg(dev->dev, "Spurious Interrupt\n");
772 		}
773 		goto end;
774 	}
775 	/* check slots available for reading */
776 	slots = mei_count_full_read_slots(dev);
777 	while (slots > 0) {
778 		dev_dbg(dev->dev, "slots to read = %08x\n", slots);
779 		rets = mei_irq_read_handler(dev, &complete_list, &slots);
780 		/* There is a race between ME write and interrupt delivery:
781 		 * Not all data is always available immediately after the
782 		 * interrupt, so try to read again on the next interrupt.
783 		 */
784 		if (rets == -ENODATA)
785 			break;
786 
787 		if (rets && dev->dev_state != MEI_DEV_RESETTING) {
788 			dev_err(dev->dev, "mei_irq_read_handler ret = %d.\n",
789 						rets);
790 			schedule_work(&dev->reset_work);
791 			goto end;
792 		}
793 	}
794 
795 	dev->hbuf_is_ready = mei_hbuf_is_ready(dev);
796 
797 	/*
798 	 * During PG handshake only allowed write is the replay to the
799 	 * PG exit message, so block calling write function
800 	 * if the pg state is not idle
801 	 */
802 	if (dev->pg_event == MEI_PG_EVENT_IDLE) {
803 		rets = mei_irq_write_handler(dev, &complete_list);
804 		dev->hbuf_is_ready = mei_hbuf_is_ready(dev);
805 	}
806 
807 	mei_irq_compl_handler(dev, &complete_list);
808 
809 end:
810 	dev_dbg(dev->dev, "interrupt thread end ret = %d\n", rets);
811 	mutex_unlock(&dev->device_lock);
812 	return IRQ_HANDLED;
813 }
814 
815 static const struct mei_hw_ops mei_me_hw_ops = {
816 
817 	.fw_status = mei_me_fw_status,
818 	.pg_state  = mei_me_pg_state,
819 
820 	.host_is_ready = mei_me_host_is_ready,
821 
822 	.hw_is_ready = mei_me_hw_is_ready,
823 	.hw_reset = mei_me_hw_reset,
824 	.hw_config = mei_me_hw_config,
825 	.hw_start = mei_me_hw_start,
826 
827 	.pg_is_enabled = mei_me_pg_is_enabled,
828 
829 	.intr_clear = mei_me_intr_clear,
830 	.intr_enable = mei_me_intr_enable,
831 	.intr_disable = mei_me_intr_disable,
832 
833 	.hbuf_free_slots = mei_me_hbuf_empty_slots,
834 	.hbuf_is_ready = mei_me_hbuf_is_empty,
835 	.hbuf_max_len = mei_me_hbuf_max_len,
836 
837 	.write = mei_me_write_message,
838 
839 	.rdbuf_full_slots = mei_me_count_full_read_slots,
840 	.read_hdr = mei_me_mecbrw_read,
841 	.read = mei_me_read_slots
842 };
843 
844 static bool mei_me_fw_type_nm(struct pci_dev *pdev)
845 {
846 	u32 reg;
847 
848 	pci_read_config_dword(pdev, PCI_CFG_HFS_2, &reg);
849 	/* make sure that bit 9 (NM) is up and bit 10 (DM) is down */
850 	return (reg & 0x600) == 0x200;
851 }
852 
853 #define MEI_CFG_FW_NM                           \
854 	.quirk_probe = mei_me_fw_type_nm
855 
856 static bool mei_me_fw_type_sps(struct pci_dev *pdev)
857 {
858 	u32 reg;
859 	/* Read ME FW Status check for SPS Firmware */
860 	pci_read_config_dword(pdev, PCI_CFG_HFS_1, &reg);
861 	/* if bits [19:16] = 15, running SPS Firmware */
862 	return (reg & 0xf0000) == 0xf0000;
863 }
864 
865 #define MEI_CFG_FW_SPS                           \
866 	.quirk_probe = mei_me_fw_type_sps
867 
868 
869 #define MEI_CFG_LEGACY_HFS                      \
870 	.fw_status.count = 0
871 
872 #define MEI_CFG_ICH_HFS                        \
873 	.fw_status.count = 1,                   \
874 	.fw_status.status[0] = PCI_CFG_HFS_1
875 
876 #define MEI_CFG_PCH_HFS                         \
877 	.fw_status.count = 2,                   \
878 	.fw_status.status[0] = PCI_CFG_HFS_1,   \
879 	.fw_status.status[1] = PCI_CFG_HFS_2
880 
881 #define MEI_CFG_PCH8_HFS                        \
882 	.fw_status.count = 6,                   \
883 	.fw_status.status[0] = PCI_CFG_HFS_1,   \
884 	.fw_status.status[1] = PCI_CFG_HFS_2,   \
885 	.fw_status.status[2] = PCI_CFG_HFS_3,   \
886 	.fw_status.status[3] = PCI_CFG_HFS_4,   \
887 	.fw_status.status[4] = PCI_CFG_HFS_5,   \
888 	.fw_status.status[5] = PCI_CFG_HFS_6
889 
890 /* ICH Legacy devices */
891 const struct mei_cfg mei_me_legacy_cfg = {
892 	MEI_CFG_LEGACY_HFS,
893 };
894 
895 /* ICH devices */
896 const struct mei_cfg mei_me_ich_cfg = {
897 	MEI_CFG_ICH_HFS,
898 };
899 
900 /* PCH devices */
901 const struct mei_cfg mei_me_pch_cfg = {
902 	MEI_CFG_PCH_HFS,
903 };
904 
905 
906 /* PCH Cougar Point and Patsburg with quirk for Node Manager exclusion */
907 const struct mei_cfg mei_me_pch_cpt_pbg_cfg = {
908 	MEI_CFG_PCH_HFS,
909 	MEI_CFG_FW_NM,
910 };
911 
912 /* PCH8 Lynx Point and newer devices */
913 const struct mei_cfg mei_me_pch8_cfg = {
914 	MEI_CFG_PCH8_HFS,
915 };
916 
917 /* PCH8 Lynx Point with quirk for SPS Firmware exclusion */
918 const struct mei_cfg mei_me_pch8_sps_cfg = {
919 	MEI_CFG_PCH8_HFS,
920 	MEI_CFG_FW_SPS,
921 };
922 
923 /**
924  * mei_me_dev_init - allocates and initializes the mei device structure
925  *
926  * @pdev: The pci device structure
927  * @cfg: per device generation config
928  *
929  * Return: The mei_device_device pointer on success, NULL on failure.
930  */
931 struct mei_device *mei_me_dev_init(struct pci_dev *pdev,
932 				   const struct mei_cfg *cfg)
933 {
934 	struct mei_device *dev;
935 	struct mei_me_hw *hw;
936 
937 	dev = kzalloc(sizeof(struct mei_device) +
938 			 sizeof(struct mei_me_hw), GFP_KERNEL);
939 	if (!dev)
940 		return NULL;
941 	hw = to_me_hw(dev);
942 
943 	mei_device_init(dev, &pdev->dev, &mei_me_hw_ops);
944 	hw->cfg = cfg;
945 	return dev;
946 }
947 
948