xref: /openbmc/linux/drivers/misc/mei/hw-me.c (revision 6cbbfe1c)
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_me_reg_write(hw, H_CSR, 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 	dev->recvd_hw_ready = false;
339 	return 0;
340 }
341 
342 /**
343  * mei_me_hw_start - hw start routine
344  *
345  * @dev: mei device
346  * Return: 0 on success, error otherwise
347  */
348 static int mei_me_hw_start(struct mei_device *dev)
349 {
350 	int ret = mei_me_hw_ready_wait(dev);
351 
352 	if (ret)
353 		return ret;
354 	dev_dbg(dev->dev, "hw is ready\n");
355 
356 	mei_me_host_set_ready(dev);
357 	return ret;
358 }
359 
360 
361 /**
362  * mei_hbuf_filled_slots - gets number of device filled buffer slots
363  *
364  * @dev: the device structure
365  *
366  * Return: number of filled slots
367  */
368 static unsigned char mei_hbuf_filled_slots(struct mei_device *dev)
369 {
370 	struct mei_me_hw *hw = to_me_hw(dev);
371 	u32 hcsr;
372 	char read_ptr, write_ptr;
373 
374 	hcsr = mei_hcsr_read(hw);
375 
376 	read_ptr = (char) ((hcsr & H_CBRP) >> 8);
377 	write_ptr = (char) ((hcsr & H_CBWP) >> 16);
378 
379 	return (unsigned char) (write_ptr - read_ptr);
380 }
381 
382 /**
383  * mei_me_hbuf_is_empty - checks if host buffer is empty.
384  *
385  * @dev: the device structure
386  *
387  * Return: true if empty, false - otherwise.
388  */
389 static bool mei_me_hbuf_is_empty(struct mei_device *dev)
390 {
391 	return mei_hbuf_filled_slots(dev) == 0;
392 }
393 
394 /**
395  * mei_me_hbuf_empty_slots - counts write empty slots.
396  *
397  * @dev: the device structure
398  *
399  * Return: -EOVERFLOW if overflow, otherwise empty slots count
400  */
401 static int mei_me_hbuf_empty_slots(struct mei_device *dev)
402 {
403 	unsigned char filled_slots, empty_slots;
404 
405 	filled_slots = mei_hbuf_filled_slots(dev);
406 	empty_slots = dev->hbuf_depth - filled_slots;
407 
408 	/* check for overflow */
409 	if (filled_slots > dev->hbuf_depth)
410 		return -EOVERFLOW;
411 
412 	return empty_slots;
413 }
414 
415 /**
416  * mei_me_hbuf_max_len - returns size of hw buffer.
417  *
418  * @dev: the device structure
419  *
420  * Return: size of hw buffer in bytes
421  */
422 static size_t mei_me_hbuf_max_len(const struct mei_device *dev)
423 {
424 	return dev->hbuf_depth * sizeof(u32) - sizeof(struct mei_msg_hdr);
425 }
426 
427 
428 /**
429  * mei_me_write_message - writes a message to mei device.
430  *
431  * @dev: the device structure
432  * @header: mei HECI header of message
433  * @buf: message payload will be written
434  *
435  * Return: -EIO if write has failed
436  */
437 static int mei_me_write_message(struct mei_device *dev,
438 			struct mei_msg_hdr *header,
439 			unsigned char *buf)
440 {
441 	struct mei_me_hw *hw = to_me_hw(dev);
442 	unsigned long rem;
443 	unsigned long length = header->length;
444 	u32 *reg_buf = (u32 *)buf;
445 	u32 hcsr;
446 	u32 dw_cnt;
447 	int i;
448 	int empty_slots;
449 
450 	dev_dbg(dev->dev, MEI_HDR_FMT, MEI_HDR_PRM(header));
451 
452 	empty_slots = mei_hbuf_empty_slots(dev);
453 	dev_dbg(dev->dev, "empty slots = %hu.\n", empty_slots);
454 
455 	dw_cnt = mei_data2slots(length);
456 	if (empty_slots < 0 || dw_cnt > empty_slots)
457 		return -EMSGSIZE;
458 
459 	mei_me_reg_write(hw, H_CB_WW, *((u32 *) header));
460 
461 	for (i = 0; i < length / 4; i++)
462 		mei_me_reg_write(hw, H_CB_WW, reg_buf[i]);
463 
464 	rem = length & 0x3;
465 	if (rem > 0) {
466 		u32 reg = 0;
467 
468 		memcpy(&reg, &buf[length - rem], rem);
469 		mei_me_reg_write(hw, H_CB_WW, reg);
470 	}
471 
472 	hcsr = mei_hcsr_read(hw) | H_IG;
473 	mei_hcsr_set(hw, hcsr);
474 	if (!mei_me_hw_is_ready(dev))
475 		return -EIO;
476 
477 	return 0;
478 }
479 
480 /**
481  * mei_me_count_full_read_slots - counts read full slots.
482  *
483  * @dev: the device structure
484  *
485  * Return: -EOVERFLOW if overflow, otherwise filled slots count
486  */
487 static int mei_me_count_full_read_slots(struct mei_device *dev)
488 {
489 	struct mei_me_hw *hw = to_me_hw(dev);
490 	u32 me_csr;
491 	char read_ptr, write_ptr;
492 	unsigned char buffer_depth, filled_slots;
493 
494 	me_csr = mei_me_mecsr_read(hw);
495 	buffer_depth = (unsigned char)((me_csr & ME_CBD_HRA) >> 24);
496 	read_ptr = (char) ((me_csr & ME_CBRP_HRA) >> 8);
497 	write_ptr = (char) ((me_csr & ME_CBWP_HRA) >> 16);
498 	filled_slots = (unsigned char) (write_ptr - read_ptr);
499 
500 	/* check for overflow */
501 	if (filled_slots > buffer_depth)
502 		return -EOVERFLOW;
503 
504 	dev_dbg(dev->dev, "filled_slots =%08x\n", filled_slots);
505 	return (int)filled_slots;
506 }
507 
508 /**
509  * mei_me_read_slots - reads a message from mei device.
510  *
511  * @dev: the device structure
512  * @buffer: message buffer will be written
513  * @buffer_length: message size will be read
514  *
515  * Return: always 0
516  */
517 static int mei_me_read_slots(struct mei_device *dev, unsigned char *buffer,
518 		    unsigned long buffer_length)
519 {
520 	struct mei_me_hw *hw = to_me_hw(dev);
521 	u32 *reg_buf = (u32 *)buffer;
522 	u32 hcsr;
523 
524 	for (; buffer_length >= sizeof(u32); buffer_length -= sizeof(u32))
525 		*reg_buf++ = mei_me_mecbrw_read(dev);
526 
527 	if (buffer_length > 0) {
528 		u32 reg = mei_me_mecbrw_read(dev);
529 
530 		memcpy(reg_buf, &reg, buffer_length);
531 	}
532 
533 	hcsr = mei_hcsr_read(hw) | H_IG;
534 	mei_hcsr_set(hw, hcsr);
535 	return 0;
536 }
537 
538 /**
539  * mei_me_pg_enter - write pg enter register
540  *
541  * @dev: the device structure
542  */
543 static void mei_me_pg_enter(struct mei_device *dev)
544 {
545 	struct mei_me_hw *hw = to_me_hw(dev);
546 	u32 reg = mei_me_reg_read(hw, H_HPG_CSR);
547 
548 	reg |= H_HPG_CSR_PGI;
549 	mei_me_reg_write(hw, H_HPG_CSR, reg);
550 }
551 
552 /**
553  * mei_me_pg_exit - write pg exit register
554  *
555  * @dev: the device structure
556  */
557 static void mei_me_pg_exit(struct mei_device *dev)
558 {
559 	struct mei_me_hw *hw = to_me_hw(dev);
560 	u32 reg = mei_me_reg_read(hw, H_HPG_CSR);
561 
562 	WARN(!(reg & H_HPG_CSR_PGI), "PGI is not set\n");
563 
564 	reg |= H_HPG_CSR_PGIHEXR;
565 	mei_me_reg_write(hw, H_HPG_CSR, reg);
566 }
567 
568 /**
569  * mei_me_pg_set_sync - perform pg entry procedure
570  *
571  * @dev: the device structure
572  *
573  * Return: 0 on success an error code otherwise
574  */
575 int mei_me_pg_set_sync(struct mei_device *dev)
576 {
577 	struct mei_me_hw *hw = to_me_hw(dev);
578 	unsigned long timeout = mei_secs_to_jiffies(MEI_PGI_TIMEOUT);
579 	int ret;
580 
581 	dev->pg_event = MEI_PG_EVENT_WAIT;
582 
583 	ret = mei_hbm_pg(dev, MEI_PG_ISOLATION_ENTRY_REQ_CMD);
584 	if (ret)
585 		return ret;
586 
587 	mutex_unlock(&dev->device_lock);
588 	wait_event_timeout(dev->wait_pg,
589 		dev->pg_event == MEI_PG_EVENT_RECEIVED, timeout);
590 	mutex_lock(&dev->device_lock);
591 
592 	if (dev->pg_event == MEI_PG_EVENT_RECEIVED) {
593 		mei_me_pg_enter(dev);
594 		ret = 0;
595 	} else {
596 		ret = -ETIME;
597 	}
598 
599 	dev->pg_event = MEI_PG_EVENT_IDLE;
600 	hw->pg_state = MEI_PG_ON;
601 
602 	return ret;
603 }
604 
605 /**
606  * mei_me_pg_unset_sync - perform pg exit procedure
607  *
608  * @dev: the device structure
609  *
610  * Return: 0 on success an error code otherwise
611  */
612 int mei_me_pg_unset_sync(struct mei_device *dev)
613 {
614 	struct mei_me_hw *hw = to_me_hw(dev);
615 	unsigned long timeout = mei_secs_to_jiffies(MEI_PGI_TIMEOUT);
616 	int ret;
617 
618 	if (dev->pg_event == MEI_PG_EVENT_RECEIVED)
619 		goto reply;
620 
621 	dev->pg_event = MEI_PG_EVENT_WAIT;
622 
623 	mei_me_pg_exit(dev);
624 
625 	mutex_unlock(&dev->device_lock);
626 	wait_event_timeout(dev->wait_pg,
627 		dev->pg_event == MEI_PG_EVENT_RECEIVED, timeout);
628 	mutex_lock(&dev->device_lock);
629 
630 reply:
631 	if (dev->pg_event == MEI_PG_EVENT_RECEIVED)
632 		ret = mei_hbm_pg(dev, MEI_PG_ISOLATION_EXIT_RES_CMD);
633 	else
634 		ret = -ETIME;
635 
636 	dev->pg_event = MEI_PG_EVENT_IDLE;
637 	hw->pg_state = MEI_PG_OFF;
638 
639 	return ret;
640 }
641 
642 /**
643  * mei_me_pg_is_enabled - detect if PG is supported by HW
644  *
645  * @dev: the device structure
646  *
647  * Return: true is pg supported, false otherwise
648  */
649 static bool mei_me_pg_is_enabled(struct mei_device *dev)
650 {
651 	struct mei_me_hw *hw = to_me_hw(dev);
652 	u32 reg = mei_me_reg_read(hw, ME_CSR_HA);
653 
654 	if ((reg & ME_PGIC_HRA) == 0)
655 		goto notsupported;
656 
657 	if (!dev->hbm_f_pg_supported)
658 		goto notsupported;
659 
660 	return true;
661 
662 notsupported:
663 	dev_dbg(dev->dev, "pg: not supported: HGP = %d hbm version %d.%d ?= %d.%d\n",
664 		!!(reg & ME_PGIC_HRA),
665 		dev->version.major_version,
666 		dev->version.minor_version,
667 		HBM_MAJOR_VERSION_PGI,
668 		HBM_MINOR_VERSION_PGI);
669 
670 	return false;
671 }
672 
673 /**
674  * mei_me_irq_quick_handler - The ISR of the MEI device
675  *
676  * @irq: The irq number
677  * @dev_id: pointer to the device structure
678  *
679  * Return: irqreturn_t
680  */
681 
682 irqreturn_t mei_me_irq_quick_handler(int irq, void *dev_id)
683 {
684 	struct mei_device *dev = (struct mei_device *) dev_id;
685 	struct mei_me_hw *hw = to_me_hw(dev);
686 	u32 csr_reg = mei_hcsr_read(hw);
687 
688 	if ((csr_reg & H_IS) != H_IS)
689 		return IRQ_NONE;
690 
691 	/* clear H_IS bit in H_CSR */
692 	mei_me_reg_write(hw, H_CSR, csr_reg);
693 
694 	return IRQ_WAKE_THREAD;
695 }
696 
697 /**
698  * mei_me_irq_thread_handler - function called after ISR to handle the interrupt
699  * processing.
700  *
701  * @irq: The irq number
702  * @dev_id: pointer to the device structure
703  *
704  * Return: irqreturn_t
705  *
706  */
707 irqreturn_t mei_me_irq_thread_handler(int irq, void *dev_id)
708 {
709 	struct mei_device *dev = (struct mei_device *) dev_id;
710 	struct mei_cl_cb complete_list;
711 	s32 slots;
712 	int rets = 0;
713 
714 	dev_dbg(dev->dev, "function called after ISR to handle the interrupt processing.\n");
715 	/* initialize our complete list */
716 	mutex_lock(&dev->device_lock);
717 	mei_io_list_init(&complete_list);
718 
719 	/* Ack the interrupt here
720 	 * In case of MSI we don't go through the quick handler */
721 	if (pci_dev_msi_enabled(to_pci_dev(dev->dev)))
722 		mei_clear_interrupts(dev);
723 
724 	/* check if ME wants a reset */
725 	if (!mei_hw_is_ready(dev) && dev->dev_state != MEI_DEV_RESETTING) {
726 		dev_warn(dev->dev, "FW not ready: resetting.\n");
727 		schedule_work(&dev->reset_work);
728 		goto end;
729 	}
730 
731 	/*  check if we need to start the dev */
732 	if (!mei_host_is_ready(dev)) {
733 		if (mei_hw_is_ready(dev)) {
734 			mei_me_hw_reset_release(dev);
735 			dev_dbg(dev->dev, "we need to start the dev.\n");
736 
737 			dev->recvd_hw_ready = true;
738 			wake_up(&dev->wait_hw_ready);
739 		} else {
740 			dev_dbg(dev->dev, "Spurious Interrupt\n");
741 		}
742 		goto end;
743 	}
744 	/* check slots available for reading */
745 	slots = mei_count_full_read_slots(dev);
746 	while (slots > 0) {
747 		dev_dbg(dev->dev, "slots to read = %08x\n", slots);
748 		rets = mei_irq_read_handler(dev, &complete_list, &slots);
749 		/* There is a race between ME write and interrupt delivery:
750 		 * Not all data is always available immediately after the
751 		 * interrupt, so try to read again on the next interrupt.
752 		 */
753 		if (rets == -ENODATA)
754 			break;
755 
756 		if (rets && dev->dev_state != MEI_DEV_RESETTING) {
757 			dev_err(dev->dev, "mei_irq_read_handler ret = %d.\n",
758 						rets);
759 			schedule_work(&dev->reset_work);
760 			goto end;
761 		}
762 	}
763 
764 	dev->hbuf_is_ready = mei_hbuf_is_ready(dev);
765 
766 	/*
767 	 * During PG handshake only allowed write is the replay to the
768 	 * PG exit message, so block calling write function
769 	 * if the pg state is not idle
770 	 */
771 	if (dev->pg_event == MEI_PG_EVENT_IDLE) {
772 		rets = mei_irq_write_handler(dev, &complete_list);
773 		dev->hbuf_is_ready = mei_hbuf_is_ready(dev);
774 	}
775 
776 	mei_irq_compl_handler(dev, &complete_list);
777 
778 end:
779 	dev_dbg(dev->dev, "interrupt thread end ret = %d\n", rets);
780 	mutex_unlock(&dev->device_lock);
781 	return IRQ_HANDLED;
782 }
783 
784 static const struct mei_hw_ops mei_me_hw_ops = {
785 
786 	.fw_status = mei_me_fw_status,
787 	.pg_state  = mei_me_pg_state,
788 
789 	.host_is_ready = mei_me_host_is_ready,
790 
791 	.hw_is_ready = mei_me_hw_is_ready,
792 	.hw_reset = mei_me_hw_reset,
793 	.hw_config = mei_me_hw_config,
794 	.hw_start = mei_me_hw_start,
795 
796 	.pg_is_enabled = mei_me_pg_is_enabled,
797 
798 	.intr_clear = mei_me_intr_clear,
799 	.intr_enable = mei_me_intr_enable,
800 	.intr_disable = mei_me_intr_disable,
801 
802 	.hbuf_free_slots = mei_me_hbuf_empty_slots,
803 	.hbuf_is_ready = mei_me_hbuf_is_empty,
804 	.hbuf_max_len = mei_me_hbuf_max_len,
805 
806 	.write = mei_me_write_message,
807 
808 	.rdbuf_full_slots = mei_me_count_full_read_slots,
809 	.read_hdr = mei_me_mecbrw_read,
810 	.read = mei_me_read_slots
811 };
812 
813 static bool mei_me_fw_type_nm(struct pci_dev *pdev)
814 {
815 	u32 reg;
816 
817 	pci_read_config_dword(pdev, PCI_CFG_HFS_2, &reg);
818 	/* make sure that bit 9 (NM) is up and bit 10 (DM) is down */
819 	return (reg & 0x600) == 0x200;
820 }
821 
822 #define MEI_CFG_FW_NM                           \
823 	.quirk_probe = mei_me_fw_type_nm
824 
825 static bool mei_me_fw_type_sps(struct pci_dev *pdev)
826 {
827 	u32 reg;
828 	/* Read ME FW Status check for SPS Firmware */
829 	pci_read_config_dword(pdev, PCI_CFG_HFS_1, &reg);
830 	/* if bits [19:16] = 15, running SPS Firmware */
831 	return (reg & 0xf0000) == 0xf0000;
832 }
833 
834 #define MEI_CFG_FW_SPS                           \
835 	.quirk_probe = mei_me_fw_type_sps
836 
837 
838 #define MEI_CFG_LEGACY_HFS                      \
839 	.fw_status.count = 0
840 
841 #define MEI_CFG_ICH_HFS                        \
842 	.fw_status.count = 1,                   \
843 	.fw_status.status[0] = PCI_CFG_HFS_1
844 
845 #define MEI_CFG_PCH_HFS                         \
846 	.fw_status.count = 2,                   \
847 	.fw_status.status[0] = PCI_CFG_HFS_1,   \
848 	.fw_status.status[1] = PCI_CFG_HFS_2
849 
850 #define MEI_CFG_PCH8_HFS                        \
851 	.fw_status.count = 6,                   \
852 	.fw_status.status[0] = PCI_CFG_HFS_1,   \
853 	.fw_status.status[1] = PCI_CFG_HFS_2,   \
854 	.fw_status.status[2] = PCI_CFG_HFS_3,   \
855 	.fw_status.status[3] = PCI_CFG_HFS_4,   \
856 	.fw_status.status[4] = PCI_CFG_HFS_5,   \
857 	.fw_status.status[5] = PCI_CFG_HFS_6
858 
859 /* ICH Legacy devices */
860 const struct mei_cfg mei_me_legacy_cfg = {
861 	MEI_CFG_LEGACY_HFS,
862 };
863 
864 /* ICH devices */
865 const struct mei_cfg mei_me_ich_cfg = {
866 	MEI_CFG_ICH_HFS,
867 };
868 
869 /* PCH devices */
870 const struct mei_cfg mei_me_pch_cfg = {
871 	MEI_CFG_PCH_HFS,
872 };
873 
874 
875 /* PCH Cougar Point and Patsburg with quirk for Node Manager exclusion */
876 const struct mei_cfg mei_me_pch_cpt_pbg_cfg = {
877 	MEI_CFG_PCH_HFS,
878 	MEI_CFG_FW_NM,
879 };
880 
881 /* PCH8 Lynx Point and newer devices */
882 const struct mei_cfg mei_me_pch8_cfg = {
883 	MEI_CFG_PCH8_HFS,
884 };
885 
886 /* PCH8 Lynx Point with quirk for SPS Firmware exclusion */
887 const struct mei_cfg mei_me_pch8_sps_cfg = {
888 	MEI_CFG_PCH8_HFS,
889 	MEI_CFG_FW_SPS,
890 };
891 
892 /**
893  * mei_me_dev_init - allocates and initializes the mei device structure
894  *
895  * @pdev: The pci device structure
896  * @cfg: per device generation config
897  *
898  * Return: The mei_device_device pointer on success, NULL on failure.
899  */
900 struct mei_device *mei_me_dev_init(struct pci_dev *pdev,
901 				   const struct mei_cfg *cfg)
902 {
903 	struct mei_device *dev;
904 	struct mei_me_hw *hw;
905 
906 	dev = kzalloc(sizeof(struct mei_device) +
907 			 sizeof(struct mei_me_hw), GFP_KERNEL);
908 	if (!dev)
909 		return NULL;
910 	hw = to_me_hw(dev);
911 
912 	mei_device_init(dev, &pdev->dev, &mei_me_hw_ops);
913 	hw->cfg = cfg;
914 	return dev;
915 }
916 
917