xref: /openbmc/linux/drivers/misc/mei/hw-me.c (revision 8b036556)
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 /**
29  * mei_me_reg_read - Reads 32bit data from the mei device
30  *
31  * @hw: the me hardware structure
32  * @offset: offset from which to read the data
33  *
34  * Return: register value (u32)
35  */
36 static inline u32 mei_me_reg_read(const struct mei_me_hw *hw,
37 			       unsigned long offset)
38 {
39 	return ioread32(hw->mem_addr + offset);
40 }
41 
42 
43 /**
44  * mei_me_reg_write - Writes 32bit data to the mei device
45  *
46  * @hw: the me hardware structure
47  * @offset: offset from which to write the data
48  * @value: register value to write (u32)
49  */
50 static inline void mei_me_reg_write(const struct mei_me_hw *hw,
51 				 unsigned long offset, u32 value)
52 {
53 	iowrite32(value, hw->mem_addr + offset);
54 }
55 
56 /**
57  * mei_me_mecbrw_read - Reads 32bit data from ME circular buffer
58  *  read window register
59  *
60  * @dev: the device structure
61  *
62  * Return: ME_CB_RW register value (u32)
63  */
64 static u32 mei_me_mecbrw_read(const struct mei_device *dev)
65 {
66 	return mei_me_reg_read(to_me_hw(dev), ME_CB_RW);
67 }
68 /**
69  * mei_me_mecsr_read - Reads 32bit data from the ME CSR
70  *
71  * @hw: the me hardware structure
72  *
73  * Return: ME_CSR_HA register value (u32)
74  */
75 static inline u32 mei_me_mecsr_read(const struct mei_me_hw *hw)
76 {
77 	return mei_me_reg_read(hw, ME_CSR_HA);
78 }
79 
80 /**
81  * mei_hcsr_read - Reads 32bit data from the host CSR
82  *
83  * @hw: the me hardware structure
84  *
85  * Return: H_CSR register value (u32)
86  */
87 static inline u32 mei_hcsr_read(const struct mei_me_hw *hw)
88 {
89 	return mei_me_reg_read(hw, H_CSR);
90 }
91 
92 /**
93  * mei_hcsr_set - writes H_CSR register to the mei device,
94  * and ignores the H_IS bit for it is write-one-to-zero.
95  *
96  * @hw: the me hardware structure
97  * @hcsr: new register value
98  */
99 static inline void mei_hcsr_set(struct mei_me_hw *hw, u32 hcsr)
100 {
101 	hcsr &= ~H_IS;
102 	mei_me_reg_write(hw, H_CSR, hcsr);
103 }
104 
105 /**
106  * mei_me_fw_status - read fw status register from pci config space
107  *
108  * @dev: mei device
109  * @fw_status: fw status register values
110  *
111  * Return: 0 on success, error otherwise
112  */
113 static int mei_me_fw_status(struct mei_device *dev,
114 			    struct mei_fw_status *fw_status)
115 {
116 	struct pci_dev *pdev = to_pci_dev(dev->dev);
117 	struct mei_me_hw *hw = to_me_hw(dev);
118 	const struct mei_fw_status *fw_src = &hw->cfg->fw_status;
119 	int ret;
120 	int i;
121 
122 	if (!fw_status)
123 		return -EINVAL;
124 
125 	fw_status->count = fw_src->count;
126 	for (i = 0; i < fw_src->count && i < MEI_FW_STATUS_MAX; i++) {
127 		ret = pci_read_config_dword(pdev,
128 			fw_src->status[i], &fw_status->status[i]);
129 		if (ret)
130 			return ret;
131 	}
132 
133 	return 0;
134 }
135 
136 /**
137  * mei_me_hw_config - configure hw dependent settings
138  *
139  * @dev: mei device
140  */
141 static void mei_me_hw_config(struct mei_device *dev)
142 {
143 	struct mei_me_hw *hw = to_me_hw(dev);
144 	u32 hcsr = mei_hcsr_read(to_me_hw(dev));
145 	/* Doesn't change in runtime */
146 	dev->hbuf_depth = (hcsr & H_CBD) >> 24;
147 
148 	hw->pg_state = MEI_PG_OFF;
149 }
150 
151 /**
152  * mei_me_pg_state  - translate internal pg state
153  *   to the mei power gating state
154  *
155  * @dev:  mei device
156  *
157  * Return: MEI_PG_OFF if aliveness is on and MEI_PG_ON otherwise
158  */
159 static inline enum mei_pg_state mei_me_pg_state(struct mei_device *dev)
160 {
161 	struct mei_me_hw *hw = to_me_hw(dev);
162 
163 	return hw->pg_state;
164 }
165 
166 /**
167  * mei_me_intr_clear - clear and stop interrupts
168  *
169  * @dev: the device structure
170  */
171 static void mei_me_intr_clear(struct mei_device *dev)
172 {
173 	struct mei_me_hw *hw = to_me_hw(dev);
174 	u32 hcsr = mei_hcsr_read(hw);
175 
176 	if ((hcsr & H_IS) == H_IS)
177 		mei_me_reg_write(hw, H_CSR, hcsr);
178 }
179 /**
180  * mei_me_intr_enable - enables mei device interrupts
181  *
182  * @dev: the device structure
183  */
184 static void mei_me_intr_enable(struct mei_device *dev)
185 {
186 	struct mei_me_hw *hw = to_me_hw(dev);
187 	u32 hcsr = mei_hcsr_read(hw);
188 
189 	hcsr |= H_IE;
190 	mei_hcsr_set(hw, hcsr);
191 }
192 
193 /**
194  * mei_me_intr_disable - disables mei device interrupts
195  *
196  * @dev: the device structure
197  */
198 static void mei_me_intr_disable(struct mei_device *dev)
199 {
200 	struct mei_me_hw *hw = to_me_hw(dev);
201 	u32 hcsr = mei_hcsr_read(hw);
202 
203 	hcsr  &= ~H_IE;
204 	mei_hcsr_set(hw, hcsr);
205 }
206 
207 /**
208  * mei_me_hw_reset_release - release device from the reset
209  *
210  * @dev: the device structure
211  */
212 static void mei_me_hw_reset_release(struct mei_device *dev)
213 {
214 	struct mei_me_hw *hw = to_me_hw(dev);
215 	u32 hcsr = mei_hcsr_read(hw);
216 
217 	hcsr |= H_IG;
218 	hcsr &= ~H_RST;
219 	mei_hcsr_set(hw, hcsr);
220 
221 	/* complete this write before we set host ready on another CPU */
222 	mmiowb();
223 }
224 /**
225  * mei_me_hw_reset - resets fw via mei csr register.
226  *
227  * @dev: the device structure
228  * @intr_enable: if interrupt should be enabled after reset.
229  *
230  * Return: always 0
231  */
232 static int mei_me_hw_reset(struct mei_device *dev, bool intr_enable)
233 {
234 	struct mei_me_hw *hw = to_me_hw(dev);
235 	u32 hcsr = mei_hcsr_read(hw);
236 
237 	/* H_RST may be found lit before reset is started,
238 	 * for example if preceding reset flow hasn't completed.
239 	 * In that case asserting H_RST will be ignored, therefore
240 	 * we need to clean H_RST bit to start a successful reset sequence.
241 	 */
242 	if ((hcsr & H_RST) == H_RST) {
243 		dev_warn(dev->dev, "H_RST is set = 0x%08X", hcsr);
244 		hcsr &= ~H_RST;
245 		mei_hcsr_set(hw, hcsr);
246 		hcsr = mei_hcsr_read(hw);
247 	}
248 
249 	hcsr |= H_RST | H_IG | H_IS;
250 
251 	if (intr_enable)
252 		hcsr |= H_IE;
253 	else
254 		hcsr &= ~H_IE;
255 
256 	dev->recvd_hw_ready = false;
257 	mei_me_reg_write(hw, H_CSR, hcsr);
258 
259 	/*
260 	 * Host reads the H_CSR once to ensure that the
261 	 * posted write to H_CSR completes.
262 	 */
263 	hcsr = mei_hcsr_read(hw);
264 
265 	if ((hcsr & H_RST) == 0)
266 		dev_warn(dev->dev, "H_RST is not set = 0x%08X", hcsr);
267 
268 	if ((hcsr & H_RDY) == H_RDY)
269 		dev_warn(dev->dev, "H_RDY is not cleared 0x%08X", hcsr);
270 
271 	if (intr_enable == false)
272 		mei_me_hw_reset_release(dev);
273 
274 	return 0;
275 }
276 
277 /**
278  * mei_me_host_set_ready - enable device
279  *
280  * @dev: mei device
281  */
282 static void mei_me_host_set_ready(struct mei_device *dev)
283 {
284 	struct mei_me_hw *hw = to_me_hw(dev);
285 	u32 hcsr = mei_hcsr_read(hw);
286 
287 	hcsr |= H_IE | H_IG | H_RDY;
288 	mei_hcsr_set(hw, hcsr);
289 }
290 
291 /**
292  * mei_me_host_is_ready - check whether the host has turned ready
293  *
294  * @dev: mei device
295  * Return: bool
296  */
297 static bool mei_me_host_is_ready(struct mei_device *dev)
298 {
299 	struct mei_me_hw *hw = to_me_hw(dev);
300 	u32 hcsr = mei_hcsr_read(hw);
301 
302 	return (hcsr & H_RDY) == H_RDY;
303 }
304 
305 /**
306  * mei_me_hw_is_ready - check whether the me(hw) has turned ready
307  *
308  * @dev: mei device
309  * Return: bool
310  */
311 static bool mei_me_hw_is_ready(struct mei_device *dev)
312 {
313 	struct mei_me_hw *hw = to_me_hw(dev);
314 	u32 mecsr = mei_me_mecsr_read(hw);
315 
316 	return (mecsr & ME_RDY_HRA) == ME_RDY_HRA;
317 }
318 
319 /**
320  * mei_me_hw_ready_wait - wait until the me(hw) has turned ready
321  *  or timeout is reached
322  *
323  * @dev: mei device
324  * Return: 0 on success, error otherwise
325  */
326 static int mei_me_hw_ready_wait(struct mei_device *dev)
327 {
328 	mutex_unlock(&dev->device_lock);
329 	wait_event_timeout(dev->wait_hw_ready,
330 			dev->recvd_hw_ready,
331 			mei_secs_to_jiffies(MEI_HW_READY_TIMEOUT));
332 	mutex_lock(&dev->device_lock);
333 	if (!dev->recvd_hw_ready) {
334 		dev_err(dev->dev, "wait hw ready failed\n");
335 		return -ETIME;
336 	}
337 
338 	mei_me_hw_reset_release(dev);
339 	dev->recvd_hw_ready = false;
340 	return 0;
341 }
342 
343 /**
344  * mei_me_hw_start - hw start routine
345  *
346  * @dev: mei device
347  * Return: 0 on success, error otherwise
348  */
349 static int mei_me_hw_start(struct mei_device *dev)
350 {
351 	int ret = mei_me_hw_ready_wait(dev);
352 
353 	if (ret)
354 		return ret;
355 	dev_dbg(dev->dev, "hw is ready\n");
356 
357 	mei_me_host_set_ready(dev);
358 	return ret;
359 }
360 
361 
362 /**
363  * mei_hbuf_filled_slots - gets number of device filled buffer slots
364  *
365  * @dev: the device structure
366  *
367  * Return: number of filled slots
368  */
369 static unsigned char mei_hbuf_filled_slots(struct mei_device *dev)
370 {
371 	struct mei_me_hw *hw = to_me_hw(dev);
372 	u32 hcsr;
373 	char read_ptr, write_ptr;
374 
375 	hcsr = mei_hcsr_read(hw);
376 
377 	read_ptr = (char) ((hcsr & H_CBRP) >> 8);
378 	write_ptr = (char) ((hcsr & H_CBWP) >> 16);
379 
380 	return (unsigned char) (write_ptr - read_ptr);
381 }
382 
383 /**
384  * mei_me_hbuf_is_empty - checks if host buffer is empty.
385  *
386  * @dev: the device structure
387  *
388  * Return: true if empty, false - otherwise.
389  */
390 static bool mei_me_hbuf_is_empty(struct mei_device *dev)
391 {
392 	return mei_hbuf_filled_slots(dev) == 0;
393 }
394 
395 /**
396  * mei_me_hbuf_empty_slots - counts write empty slots.
397  *
398  * @dev: the device structure
399  *
400  * Return: -EOVERFLOW if overflow, otherwise empty slots count
401  */
402 static int mei_me_hbuf_empty_slots(struct mei_device *dev)
403 {
404 	unsigned char filled_slots, empty_slots;
405 
406 	filled_slots = mei_hbuf_filled_slots(dev);
407 	empty_slots = dev->hbuf_depth - filled_slots;
408 
409 	/* check for overflow */
410 	if (filled_slots > dev->hbuf_depth)
411 		return -EOVERFLOW;
412 
413 	return empty_slots;
414 }
415 
416 /**
417  * mei_me_hbuf_max_len - returns size of hw buffer.
418  *
419  * @dev: the device structure
420  *
421  * Return: size of hw buffer in bytes
422  */
423 static size_t mei_me_hbuf_max_len(const struct mei_device *dev)
424 {
425 	return dev->hbuf_depth * sizeof(u32) - sizeof(struct mei_msg_hdr);
426 }
427 
428 
429 /**
430  * mei_me_write_message - writes a message to mei device.
431  *
432  * @dev: the device structure
433  * @header: mei HECI header of message
434  * @buf: message payload will be written
435  *
436  * Return: -EIO if write has failed
437  */
438 static int mei_me_write_message(struct mei_device *dev,
439 			struct mei_msg_hdr *header,
440 			unsigned char *buf)
441 {
442 	struct mei_me_hw *hw = to_me_hw(dev);
443 	unsigned long rem;
444 	unsigned long length = header->length;
445 	u32 *reg_buf = (u32 *)buf;
446 	u32 hcsr;
447 	u32 dw_cnt;
448 	int i;
449 	int empty_slots;
450 
451 	dev_dbg(dev->dev, MEI_HDR_FMT, MEI_HDR_PRM(header));
452 
453 	empty_slots = mei_hbuf_empty_slots(dev);
454 	dev_dbg(dev->dev, "empty slots = %hu.\n", empty_slots);
455 
456 	dw_cnt = mei_data2slots(length);
457 	if (empty_slots < 0 || dw_cnt > empty_slots)
458 		return -EMSGSIZE;
459 
460 	mei_me_reg_write(hw, H_CB_WW, *((u32 *) header));
461 
462 	for (i = 0; i < length / 4; i++)
463 		mei_me_reg_write(hw, H_CB_WW, reg_buf[i]);
464 
465 	rem = length & 0x3;
466 	if (rem > 0) {
467 		u32 reg = 0;
468 
469 		memcpy(&reg, &buf[length - rem], rem);
470 		mei_me_reg_write(hw, H_CB_WW, reg);
471 	}
472 
473 	hcsr = mei_hcsr_read(hw) | H_IG;
474 	mei_hcsr_set(hw, hcsr);
475 	if (!mei_me_hw_is_ready(dev))
476 		return -EIO;
477 
478 	return 0;
479 }
480 
481 /**
482  * mei_me_count_full_read_slots - counts read full slots.
483  *
484  * @dev: the device structure
485  *
486  * Return: -EOVERFLOW if overflow, otherwise filled slots count
487  */
488 static int mei_me_count_full_read_slots(struct mei_device *dev)
489 {
490 	struct mei_me_hw *hw = to_me_hw(dev);
491 	u32 me_csr;
492 	char read_ptr, write_ptr;
493 	unsigned char buffer_depth, filled_slots;
494 
495 	me_csr = mei_me_mecsr_read(hw);
496 	buffer_depth = (unsigned char)((me_csr & ME_CBD_HRA) >> 24);
497 	read_ptr = (char) ((me_csr & ME_CBRP_HRA) >> 8);
498 	write_ptr = (char) ((me_csr & ME_CBWP_HRA) >> 16);
499 	filled_slots = (unsigned char) (write_ptr - read_ptr);
500 
501 	/* check for overflow */
502 	if (filled_slots > buffer_depth)
503 		return -EOVERFLOW;
504 
505 	dev_dbg(dev->dev, "filled_slots =%08x\n", filled_slots);
506 	return (int)filled_slots;
507 }
508 
509 /**
510  * mei_me_read_slots - reads a message from mei device.
511  *
512  * @dev: the device structure
513  * @buffer: message buffer will be written
514  * @buffer_length: message size will be read
515  *
516  * Return: always 0
517  */
518 static int mei_me_read_slots(struct mei_device *dev, unsigned char *buffer,
519 		    unsigned long buffer_length)
520 {
521 	struct mei_me_hw *hw = to_me_hw(dev);
522 	u32 *reg_buf = (u32 *)buffer;
523 	u32 hcsr;
524 
525 	for (; buffer_length >= sizeof(u32); buffer_length -= sizeof(u32))
526 		*reg_buf++ = mei_me_mecbrw_read(dev);
527 
528 	if (buffer_length > 0) {
529 		u32 reg = mei_me_mecbrw_read(dev);
530 
531 		memcpy(reg_buf, &reg, buffer_length);
532 	}
533 
534 	hcsr = mei_hcsr_read(hw) | H_IG;
535 	mei_hcsr_set(hw, hcsr);
536 	return 0;
537 }
538 
539 /**
540  * mei_me_pg_enter - write pg enter register
541  *
542  * @dev: the device structure
543  */
544 static void mei_me_pg_enter(struct mei_device *dev)
545 {
546 	struct mei_me_hw *hw = to_me_hw(dev);
547 	u32 reg = mei_me_reg_read(hw, H_HPG_CSR);
548 
549 	reg |= H_HPG_CSR_PGI;
550 	mei_me_reg_write(hw, H_HPG_CSR, reg);
551 }
552 
553 /**
554  * mei_me_pg_exit - write pg exit register
555  *
556  * @dev: the device structure
557  */
558 static void mei_me_pg_exit(struct mei_device *dev)
559 {
560 	struct mei_me_hw *hw = to_me_hw(dev);
561 	u32 reg = mei_me_reg_read(hw, H_HPG_CSR);
562 
563 	WARN(!(reg & H_HPG_CSR_PGI), "PGI is not set\n");
564 
565 	reg |= H_HPG_CSR_PGIHEXR;
566 	mei_me_reg_write(hw, H_HPG_CSR, reg);
567 }
568 
569 /**
570  * mei_me_pg_set_sync - perform pg entry procedure
571  *
572  * @dev: the device structure
573  *
574  * Return: 0 on success an error code otherwise
575  */
576 int mei_me_pg_set_sync(struct mei_device *dev)
577 {
578 	struct mei_me_hw *hw = to_me_hw(dev);
579 	unsigned long timeout = mei_secs_to_jiffies(MEI_PGI_TIMEOUT);
580 	int ret;
581 
582 	dev->pg_event = MEI_PG_EVENT_WAIT;
583 
584 	ret = mei_hbm_pg(dev, MEI_PG_ISOLATION_ENTRY_REQ_CMD);
585 	if (ret)
586 		return ret;
587 
588 	mutex_unlock(&dev->device_lock);
589 	wait_event_timeout(dev->wait_pg,
590 		dev->pg_event == MEI_PG_EVENT_RECEIVED, timeout);
591 	mutex_lock(&dev->device_lock);
592 
593 	if (dev->pg_event == MEI_PG_EVENT_RECEIVED) {
594 		mei_me_pg_enter(dev);
595 		ret = 0;
596 	} else {
597 		ret = -ETIME;
598 	}
599 
600 	dev->pg_event = MEI_PG_EVENT_IDLE;
601 	hw->pg_state = MEI_PG_ON;
602 
603 	return ret;
604 }
605 
606 /**
607  * mei_me_pg_unset_sync - perform pg exit procedure
608  *
609  * @dev: the device structure
610  *
611  * Return: 0 on success an error code otherwise
612  */
613 int mei_me_pg_unset_sync(struct mei_device *dev)
614 {
615 	struct mei_me_hw *hw = to_me_hw(dev);
616 	unsigned long timeout = mei_secs_to_jiffies(MEI_PGI_TIMEOUT);
617 	int ret;
618 
619 	if (dev->pg_event == MEI_PG_EVENT_RECEIVED)
620 		goto reply;
621 
622 	dev->pg_event = MEI_PG_EVENT_WAIT;
623 
624 	mei_me_pg_exit(dev);
625 
626 	mutex_unlock(&dev->device_lock);
627 	wait_event_timeout(dev->wait_pg,
628 		dev->pg_event == MEI_PG_EVENT_RECEIVED, timeout);
629 	mutex_lock(&dev->device_lock);
630 
631 reply:
632 	if (dev->pg_event == MEI_PG_EVENT_RECEIVED)
633 		ret = mei_hbm_pg(dev, MEI_PG_ISOLATION_EXIT_RES_CMD);
634 	else
635 		ret = -ETIME;
636 
637 	dev->pg_event = MEI_PG_EVENT_IDLE;
638 	hw->pg_state = MEI_PG_OFF;
639 
640 	return ret;
641 }
642 
643 /**
644  * mei_me_pg_is_enabled - detect if PG is supported by HW
645  *
646  * @dev: the device structure
647  *
648  * Return: true is pg supported, false otherwise
649  */
650 static bool mei_me_pg_is_enabled(struct mei_device *dev)
651 {
652 	struct mei_me_hw *hw = to_me_hw(dev);
653 	u32 reg = mei_me_reg_read(hw, ME_CSR_HA);
654 
655 	if ((reg & ME_PGIC_HRA) == 0)
656 		goto notsupported;
657 
658 	if (!dev->hbm_f_pg_supported)
659 		goto notsupported;
660 
661 	return true;
662 
663 notsupported:
664 	dev_dbg(dev->dev, "pg: not supported: HGP = %d hbm version %d.%d ?= %d.%d\n",
665 		!!(reg & ME_PGIC_HRA),
666 		dev->version.major_version,
667 		dev->version.minor_version,
668 		HBM_MAJOR_VERSION_PGI,
669 		HBM_MINOR_VERSION_PGI);
670 
671 	return false;
672 }
673 
674 /**
675  * mei_me_irq_quick_handler - The ISR of the MEI device
676  *
677  * @irq: The irq number
678  * @dev_id: pointer to the device structure
679  *
680  * Return: irqreturn_t
681  */
682 
683 irqreturn_t mei_me_irq_quick_handler(int irq, void *dev_id)
684 {
685 	struct mei_device *dev = (struct mei_device *) dev_id;
686 	struct mei_me_hw *hw = to_me_hw(dev);
687 	u32 csr_reg = mei_hcsr_read(hw);
688 
689 	if ((csr_reg & H_IS) != H_IS)
690 		return IRQ_NONE;
691 
692 	/* clear H_IS bit in H_CSR */
693 	mei_me_reg_write(hw, H_CSR, csr_reg);
694 
695 	return IRQ_WAKE_THREAD;
696 }
697 
698 /**
699  * mei_me_irq_thread_handler - function called after ISR to handle the interrupt
700  * processing.
701  *
702  * @irq: The irq number
703  * @dev_id: pointer to the device structure
704  *
705  * Return: irqreturn_t
706  *
707  */
708 irqreturn_t mei_me_irq_thread_handler(int irq, void *dev_id)
709 {
710 	struct mei_device *dev = (struct mei_device *) dev_id;
711 	struct mei_cl_cb complete_list;
712 	s32 slots;
713 	int rets = 0;
714 
715 	dev_dbg(dev->dev, "function called after ISR to handle the interrupt processing.\n");
716 	/* initialize our complete list */
717 	mutex_lock(&dev->device_lock);
718 	mei_io_list_init(&complete_list);
719 
720 	/* Ack the interrupt here
721 	 * In case of MSI we don't go through the quick handler */
722 	if (pci_dev_msi_enabled(to_pci_dev(dev->dev)))
723 		mei_clear_interrupts(dev);
724 
725 	/* check if ME wants a reset */
726 	if (!mei_hw_is_ready(dev) && dev->dev_state != MEI_DEV_RESETTING) {
727 		dev_warn(dev->dev, "FW not ready: resetting.\n");
728 		schedule_work(&dev->reset_work);
729 		goto end;
730 	}
731 
732 	/*  check if we need to start the dev */
733 	if (!mei_host_is_ready(dev)) {
734 		if (mei_hw_is_ready(dev)) {
735 			dev_dbg(dev->dev, "we need to start the dev.\n");
736 			dev->recvd_hw_ready = true;
737 			wake_up(&dev->wait_hw_ready);
738 		} else {
739 			dev_dbg(dev->dev, "Spurious Interrupt\n");
740 		}
741 		goto end;
742 	}
743 	/* check slots available for reading */
744 	slots = mei_count_full_read_slots(dev);
745 	while (slots > 0) {
746 		dev_dbg(dev->dev, "slots to read = %08x\n", slots);
747 		rets = mei_irq_read_handler(dev, &complete_list, &slots);
748 		/* There is a race between ME write and interrupt delivery:
749 		 * Not all data is always available immediately after the
750 		 * interrupt, so try to read again on the next interrupt.
751 		 */
752 		if (rets == -ENODATA)
753 			break;
754 
755 		if (rets && dev->dev_state != MEI_DEV_RESETTING) {
756 			dev_err(dev->dev, "mei_irq_read_handler ret = %d.\n",
757 						rets);
758 			schedule_work(&dev->reset_work);
759 			goto end;
760 		}
761 	}
762 
763 	dev->hbuf_is_ready = mei_hbuf_is_ready(dev);
764 
765 	/*
766 	 * During PG handshake only allowed write is the replay to the
767 	 * PG exit message, so block calling write function
768 	 * if the pg state is not idle
769 	 */
770 	if (dev->pg_event == MEI_PG_EVENT_IDLE) {
771 		rets = mei_irq_write_handler(dev, &complete_list);
772 		dev->hbuf_is_ready = mei_hbuf_is_ready(dev);
773 	}
774 
775 	mei_irq_compl_handler(dev, &complete_list);
776 
777 end:
778 	dev_dbg(dev->dev, "interrupt thread end ret = %d\n", rets);
779 	mutex_unlock(&dev->device_lock);
780 	return IRQ_HANDLED;
781 }
782 
783 static const struct mei_hw_ops mei_me_hw_ops = {
784 
785 	.fw_status = mei_me_fw_status,
786 	.pg_state  = mei_me_pg_state,
787 
788 	.host_is_ready = mei_me_host_is_ready,
789 
790 	.hw_is_ready = mei_me_hw_is_ready,
791 	.hw_reset = mei_me_hw_reset,
792 	.hw_config = mei_me_hw_config,
793 	.hw_start = mei_me_hw_start,
794 
795 	.pg_is_enabled = mei_me_pg_is_enabled,
796 
797 	.intr_clear = mei_me_intr_clear,
798 	.intr_enable = mei_me_intr_enable,
799 	.intr_disable = mei_me_intr_disable,
800 
801 	.hbuf_free_slots = mei_me_hbuf_empty_slots,
802 	.hbuf_is_ready = mei_me_hbuf_is_empty,
803 	.hbuf_max_len = mei_me_hbuf_max_len,
804 
805 	.write = mei_me_write_message,
806 
807 	.rdbuf_full_slots = mei_me_count_full_read_slots,
808 	.read_hdr = mei_me_mecbrw_read,
809 	.read = mei_me_read_slots
810 };
811 
812 static bool mei_me_fw_type_nm(struct pci_dev *pdev)
813 {
814 	u32 reg;
815 
816 	pci_read_config_dword(pdev, PCI_CFG_HFS_2, &reg);
817 	/* make sure that bit 9 (NM) is up and bit 10 (DM) is down */
818 	return (reg & 0x600) == 0x200;
819 }
820 
821 #define MEI_CFG_FW_NM                           \
822 	.quirk_probe = mei_me_fw_type_nm
823 
824 static bool mei_me_fw_type_sps(struct pci_dev *pdev)
825 {
826 	u32 reg;
827 	/* Read ME FW Status check for SPS Firmware */
828 	pci_read_config_dword(pdev, PCI_CFG_HFS_1, &reg);
829 	/* if bits [19:16] = 15, running SPS Firmware */
830 	return (reg & 0xf0000) == 0xf0000;
831 }
832 
833 #define MEI_CFG_FW_SPS                           \
834 	.quirk_probe = mei_me_fw_type_sps
835 
836 
837 #define MEI_CFG_LEGACY_HFS                      \
838 	.fw_status.count = 0
839 
840 #define MEI_CFG_ICH_HFS                        \
841 	.fw_status.count = 1,                   \
842 	.fw_status.status[0] = PCI_CFG_HFS_1
843 
844 #define MEI_CFG_PCH_HFS                         \
845 	.fw_status.count = 2,                   \
846 	.fw_status.status[0] = PCI_CFG_HFS_1,   \
847 	.fw_status.status[1] = PCI_CFG_HFS_2
848 
849 #define MEI_CFG_PCH8_HFS                        \
850 	.fw_status.count = 6,                   \
851 	.fw_status.status[0] = PCI_CFG_HFS_1,   \
852 	.fw_status.status[1] = PCI_CFG_HFS_2,   \
853 	.fw_status.status[2] = PCI_CFG_HFS_3,   \
854 	.fw_status.status[3] = PCI_CFG_HFS_4,   \
855 	.fw_status.status[4] = PCI_CFG_HFS_5,   \
856 	.fw_status.status[5] = PCI_CFG_HFS_6
857 
858 /* ICH Legacy devices */
859 const struct mei_cfg mei_me_legacy_cfg = {
860 	MEI_CFG_LEGACY_HFS,
861 };
862 
863 /* ICH devices */
864 const struct mei_cfg mei_me_ich_cfg = {
865 	MEI_CFG_ICH_HFS,
866 };
867 
868 /* PCH devices */
869 const struct mei_cfg mei_me_pch_cfg = {
870 	MEI_CFG_PCH_HFS,
871 };
872 
873 
874 /* PCH Cougar Point and Patsburg with quirk for Node Manager exclusion */
875 const struct mei_cfg mei_me_pch_cpt_pbg_cfg = {
876 	MEI_CFG_PCH_HFS,
877 	MEI_CFG_FW_NM,
878 };
879 
880 /* PCH8 Lynx Point and newer devices */
881 const struct mei_cfg mei_me_pch8_cfg = {
882 	MEI_CFG_PCH8_HFS,
883 };
884 
885 /* PCH8 Lynx Point with quirk for SPS Firmware exclusion */
886 const struct mei_cfg mei_me_pch8_sps_cfg = {
887 	MEI_CFG_PCH8_HFS,
888 	MEI_CFG_FW_SPS,
889 };
890 
891 /**
892  * mei_me_dev_init - allocates and initializes the mei device structure
893  *
894  * @pdev: The pci device structure
895  * @cfg: per device generation config
896  *
897  * Return: The mei_device_device pointer on success, NULL on failure.
898  */
899 struct mei_device *mei_me_dev_init(struct pci_dev *pdev,
900 				   const struct mei_cfg *cfg)
901 {
902 	struct mei_device *dev;
903 	struct mei_me_hw *hw;
904 
905 	dev = kzalloc(sizeof(struct mei_device) +
906 			 sizeof(struct mei_me_hw), GFP_KERNEL);
907 	if (!dev)
908 		return NULL;
909 	hw = to_me_hw(dev);
910 
911 	mei_device_init(dev, &pdev->dev, &mei_me_hw_ops);
912 	hw->cfg = cfg;
913 	return dev;
914 }
915 
916