xref: /openbmc/linux/drivers/misc/mei/hw-me.c (revision 8684014d)
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 	hcsr |= H_RST | H_IG | H_IS;
238 
239 	if (intr_enable)
240 		hcsr |= H_IE;
241 	else
242 		hcsr &= ~H_IE;
243 
244 	dev->recvd_hw_ready = false;
245 	mei_me_reg_write(hw, H_CSR, hcsr);
246 
247 	/*
248 	 * Host reads the H_CSR once to ensure that the
249 	 * posted write to H_CSR completes.
250 	 */
251 	hcsr = mei_hcsr_read(hw);
252 
253 	if ((hcsr & H_RST) == 0)
254 		dev_warn(dev->dev, "H_RST is not set = 0x%08X", hcsr);
255 
256 	if ((hcsr & H_RDY) == H_RDY)
257 		dev_warn(dev->dev, "H_RDY is not cleared 0x%08X", hcsr);
258 
259 	if (intr_enable == false)
260 		mei_me_hw_reset_release(dev);
261 
262 	return 0;
263 }
264 
265 /**
266  * mei_me_host_set_ready - enable device
267  *
268  * @dev: mei device
269  */
270 static void mei_me_host_set_ready(struct mei_device *dev)
271 {
272 	struct mei_me_hw *hw = to_me_hw(dev);
273 	u32 hcsr = mei_hcsr_read(hw);
274 
275 	hcsr |= H_IE | H_IG | H_RDY;
276 	mei_hcsr_set(hw, hcsr);
277 }
278 
279 /**
280  * mei_me_host_is_ready - check whether the host has turned ready
281  *
282  * @dev: mei device
283  * Return: bool
284  */
285 static bool mei_me_host_is_ready(struct mei_device *dev)
286 {
287 	struct mei_me_hw *hw = to_me_hw(dev);
288 	u32 hcsr = mei_hcsr_read(hw);
289 
290 	return (hcsr & H_RDY) == H_RDY;
291 }
292 
293 /**
294  * mei_me_hw_is_ready - check whether the me(hw) has turned ready
295  *
296  * @dev: mei device
297  * Return: bool
298  */
299 static bool mei_me_hw_is_ready(struct mei_device *dev)
300 {
301 	struct mei_me_hw *hw = to_me_hw(dev);
302 	u32 mecsr = mei_me_mecsr_read(hw);
303 
304 	return (mecsr & ME_RDY_HRA) == ME_RDY_HRA;
305 }
306 
307 /**
308  * mei_me_hw_ready_wait - wait until the me(hw) has turned ready
309  *  or timeout is reached
310  *
311  * @dev: mei device
312  * Return: 0 on success, error otherwise
313  */
314 static int mei_me_hw_ready_wait(struct mei_device *dev)
315 {
316 	mutex_unlock(&dev->device_lock);
317 	wait_event_timeout(dev->wait_hw_ready,
318 			dev->recvd_hw_ready,
319 			mei_secs_to_jiffies(MEI_HW_READY_TIMEOUT));
320 	mutex_lock(&dev->device_lock);
321 	if (!dev->recvd_hw_ready) {
322 		dev_err(dev->dev, "wait hw ready failed\n");
323 		return -ETIME;
324 	}
325 
326 	dev->recvd_hw_ready = false;
327 	return 0;
328 }
329 
330 /**
331  * mei_me_hw_start - hw start routine
332  *
333  * @dev: mei device
334  * Return: 0 on success, error otherwise
335  */
336 static int mei_me_hw_start(struct mei_device *dev)
337 {
338 	int ret = mei_me_hw_ready_wait(dev);
339 
340 	if (ret)
341 		return ret;
342 	dev_dbg(dev->dev, "hw is ready\n");
343 
344 	mei_me_host_set_ready(dev);
345 	return ret;
346 }
347 
348 
349 /**
350  * mei_hbuf_filled_slots - gets number of device filled buffer slots
351  *
352  * @dev: the device structure
353  *
354  * Return: number of filled slots
355  */
356 static unsigned char mei_hbuf_filled_slots(struct mei_device *dev)
357 {
358 	struct mei_me_hw *hw = to_me_hw(dev);
359 	u32 hcsr;
360 	char read_ptr, write_ptr;
361 
362 	hcsr = mei_hcsr_read(hw);
363 
364 	read_ptr = (char) ((hcsr & H_CBRP) >> 8);
365 	write_ptr = (char) ((hcsr & H_CBWP) >> 16);
366 
367 	return (unsigned char) (write_ptr - read_ptr);
368 }
369 
370 /**
371  * mei_me_hbuf_is_empty - checks if host buffer is empty.
372  *
373  * @dev: the device structure
374  *
375  * Return: true if empty, false - otherwise.
376  */
377 static bool mei_me_hbuf_is_empty(struct mei_device *dev)
378 {
379 	return mei_hbuf_filled_slots(dev) == 0;
380 }
381 
382 /**
383  * mei_me_hbuf_empty_slots - counts write empty slots.
384  *
385  * @dev: the device structure
386  *
387  * Return: -EOVERFLOW if overflow, otherwise empty slots count
388  */
389 static int mei_me_hbuf_empty_slots(struct mei_device *dev)
390 {
391 	unsigned char filled_slots, empty_slots;
392 
393 	filled_slots = mei_hbuf_filled_slots(dev);
394 	empty_slots = dev->hbuf_depth - filled_slots;
395 
396 	/* check for overflow */
397 	if (filled_slots > dev->hbuf_depth)
398 		return -EOVERFLOW;
399 
400 	return empty_slots;
401 }
402 
403 /**
404  * mei_me_hbuf_max_len - returns size of hw buffer.
405  *
406  * @dev: the device structure
407  *
408  * Return: size of hw buffer in bytes
409  */
410 static size_t mei_me_hbuf_max_len(const struct mei_device *dev)
411 {
412 	return dev->hbuf_depth * sizeof(u32) - sizeof(struct mei_msg_hdr);
413 }
414 
415 
416 /**
417  * mei_me_write_message - writes a message to mei device.
418  *
419  * @dev: the device structure
420  * @header: mei HECI header of message
421  * @buf: message payload will be written
422  *
423  * Return: -EIO if write has failed
424  */
425 static int mei_me_write_message(struct mei_device *dev,
426 			struct mei_msg_hdr *header,
427 			unsigned char *buf)
428 {
429 	struct mei_me_hw *hw = to_me_hw(dev);
430 	unsigned long rem;
431 	unsigned long length = header->length;
432 	u32 *reg_buf = (u32 *)buf;
433 	u32 hcsr;
434 	u32 dw_cnt;
435 	int i;
436 	int empty_slots;
437 
438 	dev_dbg(dev->dev, MEI_HDR_FMT, MEI_HDR_PRM(header));
439 
440 	empty_slots = mei_hbuf_empty_slots(dev);
441 	dev_dbg(dev->dev, "empty slots = %hu.\n", empty_slots);
442 
443 	dw_cnt = mei_data2slots(length);
444 	if (empty_slots < 0 || dw_cnt > empty_slots)
445 		return -EMSGSIZE;
446 
447 	mei_me_reg_write(hw, H_CB_WW, *((u32 *) header));
448 
449 	for (i = 0; i < length / 4; i++)
450 		mei_me_reg_write(hw, H_CB_WW, reg_buf[i]);
451 
452 	rem = length & 0x3;
453 	if (rem > 0) {
454 		u32 reg = 0;
455 
456 		memcpy(&reg, &buf[length - rem], rem);
457 		mei_me_reg_write(hw, H_CB_WW, reg);
458 	}
459 
460 	hcsr = mei_hcsr_read(hw) | H_IG;
461 	mei_hcsr_set(hw, hcsr);
462 	if (!mei_me_hw_is_ready(dev))
463 		return -EIO;
464 
465 	return 0;
466 }
467 
468 /**
469  * mei_me_count_full_read_slots - counts read full slots.
470  *
471  * @dev: the device structure
472  *
473  * Return: -EOVERFLOW if overflow, otherwise filled slots count
474  */
475 static int mei_me_count_full_read_slots(struct mei_device *dev)
476 {
477 	struct mei_me_hw *hw = to_me_hw(dev);
478 	u32 me_csr;
479 	char read_ptr, write_ptr;
480 	unsigned char buffer_depth, filled_slots;
481 
482 	me_csr = mei_me_mecsr_read(hw);
483 	buffer_depth = (unsigned char)((me_csr & ME_CBD_HRA) >> 24);
484 	read_ptr = (char) ((me_csr & ME_CBRP_HRA) >> 8);
485 	write_ptr = (char) ((me_csr & ME_CBWP_HRA) >> 16);
486 	filled_slots = (unsigned char) (write_ptr - read_ptr);
487 
488 	/* check for overflow */
489 	if (filled_slots > buffer_depth)
490 		return -EOVERFLOW;
491 
492 	dev_dbg(dev->dev, "filled_slots =%08x\n", filled_slots);
493 	return (int)filled_slots;
494 }
495 
496 /**
497  * mei_me_read_slots - reads a message from mei device.
498  *
499  * @dev: the device structure
500  * @buffer: message buffer will be written
501  * @buffer_length: message size will be read
502  *
503  * Return: always 0
504  */
505 static int mei_me_read_slots(struct mei_device *dev, unsigned char *buffer,
506 		    unsigned long buffer_length)
507 {
508 	struct mei_me_hw *hw = to_me_hw(dev);
509 	u32 *reg_buf = (u32 *)buffer;
510 	u32 hcsr;
511 
512 	for (; buffer_length >= sizeof(u32); buffer_length -= sizeof(u32))
513 		*reg_buf++ = mei_me_mecbrw_read(dev);
514 
515 	if (buffer_length > 0) {
516 		u32 reg = mei_me_mecbrw_read(dev);
517 
518 		memcpy(reg_buf, &reg, buffer_length);
519 	}
520 
521 	hcsr = mei_hcsr_read(hw) | H_IG;
522 	mei_hcsr_set(hw, hcsr);
523 	return 0;
524 }
525 
526 /**
527  * mei_me_pg_enter - write pg enter register
528  *
529  * @dev: the device structure
530  */
531 static void mei_me_pg_enter(struct mei_device *dev)
532 {
533 	struct mei_me_hw *hw = to_me_hw(dev);
534 	u32 reg = mei_me_reg_read(hw, H_HPG_CSR);
535 
536 	reg |= H_HPG_CSR_PGI;
537 	mei_me_reg_write(hw, H_HPG_CSR, reg);
538 }
539 
540 /**
541  * mei_me_pg_exit - write pg exit register
542  *
543  * @dev: the device structure
544  */
545 static void mei_me_pg_exit(struct mei_device *dev)
546 {
547 	struct mei_me_hw *hw = to_me_hw(dev);
548 	u32 reg = mei_me_reg_read(hw, H_HPG_CSR);
549 
550 	WARN(!(reg & H_HPG_CSR_PGI), "PGI is not set\n");
551 
552 	reg |= H_HPG_CSR_PGIHEXR;
553 	mei_me_reg_write(hw, H_HPG_CSR, reg);
554 }
555 
556 /**
557  * mei_me_pg_set_sync - perform pg entry procedure
558  *
559  * @dev: the device structure
560  *
561  * Return: 0 on success an error code otherwise
562  */
563 int mei_me_pg_set_sync(struct mei_device *dev)
564 {
565 	struct mei_me_hw *hw = to_me_hw(dev);
566 	unsigned long timeout = mei_secs_to_jiffies(MEI_PGI_TIMEOUT);
567 	int ret;
568 
569 	dev->pg_event = MEI_PG_EVENT_WAIT;
570 
571 	ret = mei_hbm_pg(dev, MEI_PG_ISOLATION_ENTRY_REQ_CMD);
572 	if (ret)
573 		return ret;
574 
575 	mutex_unlock(&dev->device_lock);
576 	wait_event_timeout(dev->wait_pg,
577 		dev->pg_event == MEI_PG_EVENT_RECEIVED, timeout);
578 	mutex_lock(&dev->device_lock);
579 
580 	if (dev->pg_event == MEI_PG_EVENT_RECEIVED) {
581 		mei_me_pg_enter(dev);
582 		ret = 0;
583 	} else {
584 		ret = -ETIME;
585 	}
586 
587 	dev->pg_event = MEI_PG_EVENT_IDLE;
588 	hw->pg_state = MEI_PG_ON;
589 
590 	return ret;
591 }
592 
593 /**
594  * mei_me_pg_unset_sync - perform pg exit procedure
595  *
596  * @dev: the device structure
597  *
598  * Return: 0 on success an error code otherwise
599  */
600 int mei_me_pg_unset_sync(struct mei_device *dev)
601 {
602 	struct mei_me_hw *hw = to_me_hw(dev);
603 	unsigned long timeout = mei_secs_to_jiffies(MEI_PGI_TIMEOUT);
604 	int ret;
605 
606 	if (dev->pg_event == MEI_PG_EVENT_RECEIVED)
607 		goto reply;
608 
609 	dev->pg_event = MEI_PG_EVENT_WAIT;
610 
611 	mei_me_pg_exit(dev);
612 
613 	mutex_unlock(&dev->device_lock);
614 	wait_event_timeout(dev->wait_pg,
615 		dev->pg_event == MEI_PG_EVENT_RECEIVED, timeout);
616 	mutex_lock(&dev->device_lock);
617 
618 reply:
619 	if (dev->pg_event == MEI_PG_EVENT_RECEIVED)
620 		ret = mei_hbm_pg(dev, MEI_PG_ISOLATION_EXIT_RES_CMD);
621 	else
622 		ret = -ETIME;
623 
624 	dev->pg_event = MEI_PG_EVENT_IDLE;
625 	hw->pg_state = MEI_PG_OFF;
626 
627 	return ret;
628 }
629 
630 /**
631  * mei_me_pg_is_enabled - detect if PG is supported by HW
632  *
633  * @dev: the device structure
634  *
635  * Return: true is pg supported, false otherwise
636  */
637 static bool mei_me_pg_is_enabled(struct mei_device *dev)
638 {
639 	struct mei_me_hw *hw = to_me_hw(dev);
640 	u32 reg = mei_me_reg_read(hw, ME_CSR_HA);
641 
642 	if ((reg & ME_PGIC_HRA) == 0)
643 		goto notsupported;
644 
645 	if (!dev->hbm_f_pg_supported)
646 		goto notsupported;
647 
648 	return true;
649 
650 notsupported:
651 	dev_dbg(dev->dev, "pg: not supported: HGP = %d hbm version %d.%d ?= %d.%d\n",
652 		!!(reg & ME_PGIC_HRA),
653 		dev->version.major_version,
654 		dev->version.minor_version,
655 		HBM_MAJOR_VERSION_PGI,
656 		HBM_MINOR_VERSION_PGI);
657 
658 	return false;
659 }
660 
661 /**
662  * mei_me_irq_quick_handler - The ISR of the MEI device
663  *
664  * @irq: The irq number
665  * @dev_id: pointer to the device structure
666  *
667  * Return: irqreturn_t
668  */
669 
670 irqreturn_t mei_me_irq_quick_handler(int irq, void *dev_id)
671 {
672 	struct mei_device *dev = (struct mei_device *) dev_id;
673 	struct mei_me_hw *hw = to_me_hw(dev);
674 	u32 csr_reg = mei_hcsr_read(hw);
675 
676 	if ((csr_reg & H_IS) != H_IS)
677 		return IRQ_NONE;
678 
679 	/* clear H_IS bit in H_CSR */
680 	mei_me_reg_write(hw, H_CSR, csr_reg);
681 
682 	return IRQ_WAKE_THREAD;
683 }
684 
685 /**
686  * mei_me_irq_thread_handler - function called after ISR to handle the interrupt
687  * processing.
688  *
689  * @irq: The irq number
690  * @dev_id: pointer to the device structure
691  *
692  * Return: irqreturn_t
693  *
694  */
695 irqreturn_t mei_me_irq_thread_handler(int irq, void *dev_id)
696 {
697 	struct mei_device *dev = (struct mei_device *) dev_id;
698 	struct mei_cl_cb complete_list;
699 	s32 slots;
700 	int rets = 0;
701 
702 	dev_dbg(dev->dev, "function called after ISR to handle the interrupt processing.\n");
703 	/* initialize our complete list */
704 	mutex_lock(&dev->device_lock);
705 	mei_io_list_init(&complete_list);
706 
707 	/* Ack the interrupt here
708 	 * In case of MSI we don't go through the quick handler */
709 	if (pci_dev_msi_enabled(to_pci_dev(dev->dev)))
710 		mei_clear_interrupts(dev);
711 
712 	/* check if ME wants a reset */
713 	if (!mei_hw_is_ready(dev) && dev->dev_state != MEI_DEV_RESETTING) {
714 		dev_warn(dev->dev, "FW not ready: resetting.\n");
715 		schedule_work(&dev->reset_work);
716 		goto end;
717 	}
718 
719 	/*  check if we need to start the dev */
720 	if (!mei_host_is_ready(dev)) {
721 		if (mei_hw_is_ready(dev)) {
722 			mei_me_hw_reset_release(dev);
723 			dev_dbg(dev->dev, "we need to start the dev.\n");
724 
725 			dev->recvd_hw_ready = true;
726 			wake_up(&dev->wait_hw_ready);
727 		} else {
728 			dev_dbg(dev->dev, "Spurious Interrupt\n");
729 		}
730 		goto end;
731 	}
732 	/* check slots available for reading */
733 	slots = mei_count_full_read_slots(dev);
734 	while (slots > 0) {
735 		dev_dbg(dev->dev, "slots to read = %08x\n", slots);
736 		rets = mei_irq_read_handler(dev, &complete_list, &slots);
737 		/* There is a race between ME write and interrupt delivery:
738 		 * Not all data is always available immediately after the
739 		 * interrupt, so try to read again on the next interrupt.
740 		 */
741 		if (rets == -ENODATA)
742 			break;
743 
744 		if (rets && dev->dev_state != MEI_DEV_RESETTING) {
745 			dev_err(dev->dev, "mei_irq_read_handler ret = %d.\n",
746 						rets);
747 			schedule_work(&dev->reset_work);
748 			goto end;
749 		}
750 	}
751 
752 	dev->hbuf_is_ready = mei_hbuf_is_ready(dev);
753 
754 	/*
755 	 * During PG handshake only allowed write is the replay to the
756 	 * PG exit message, so block calling write function
757 	 * if the pg state is not idle
758 	 */
759 	if (dev->pg_event == MEI_PG_EVENT_IDLE) {
760 		rets = mei_irq_write_handler(dev, &complete_list);
761 		dev->hbuf_is_ready = mei_hbuf_is_ready(dev);
762 	}
763 
764 	mei_irq_compl_handler(dev, &complete_list);
765 
766 end:
767 	dev_dbg(dev->dev, "interrupt thread end ret = %d\n", rets);
768 	mutex_unlock(&dev->device_lock);
769 	return IRQ_HANDLED;
770 }
771 
772 static const struct mei_hw_ops mei_me_hw_ops = {
773 
774 	.fw_status = mei_me_fw_status,
775 	.pg_state  = mei_me_pg_state,
776 
777 	.host_is_ready = mei_me_host_is_ready,
778 
779 	.hw_is_ready = mei_me_hw_is_ready,
780 	.hw_reset = mei_me_hw_reset,
781 	.hw_config = mei_me_hw_config,
782 	.hw_start = mei_me_hw_start,
783 
784 	.pg_is_enabled = mei_me_pg_is_enabled,
785 
786 	.intr_clear = mei_me_intr_clear,
787 	.intr_enable = mei_me_intr_enable,
788 	.intr_disable = mei_me_intr_disable,
789 
790 	.hbuf_free_slots = mei_me_hbuf_empty_slots,
791 	.hbuf_is_ready = mei_me_hbuf_is_empty,
792 	.hbuf_max_len = mei_me_hbuf_max_len,
793 
794 	.write = mei_me_write_message,
795 
796 	.rdbuf_full_slots = mei_me_count_full_read_slots,
797 	.read_hdr = mei_me_mecbrw_read,
798 	.read = mei_me_read_slots
799 };
800 
801 static bool mei_me_fw_type_nm(struct pci_dev *pdev)
802 {
803 	u32 reg;
804 
805 	pci_read_config_dword(pdev, PCI_CFG_HFS_2, &reg);
806 	/* make sure that bit 9 (NM) is up and bit 10 (DM) is down */
807 	return (reg & 0x600) == 0x200;
808 }
809 
810 #define MEI_CFG_FW_NM                           \
811 	.quirk_probe = mei_me_fw_type_nm
812 
813 static bool mei_me_fw_type_sps(struct pci_dev *pdev)
814 {
815 	u32 reg;
816 	/* Read ME FW Status check for SPS Firmware */
817 	pci_read_config_dword(pdev, PCI_CFG_HFS_1, &reg);
818 	/* if bits [19:16] = 15, running SPS Firmware */
819 	return (reg & 0xf0000) == 0xf0000;
820 }
821 
822 #define MEI_CFG_FW_SPS                           \
823 	.quirk_probe = mei_me_fw_type_sps
824 
825 
826 #define MEI_CFG_LEGACY_HFS                      \
827 	.fw_status.count = 0
828 
829 #define MEI_CFG_ICH_HFS                        \
830 	.fw_status.count = 1,                   \
831 	.fw_status.status[0] = PCI_CFG_HFS_1
832 
833 #define MEI_CFG_PCH_HFS                         \
834 	.fw_status.count = 2,                   \
835 	.fw_status.status[0] = PCI_CFG_HFS_1,   \
836 	.fw_status.status[1] = PCI_CFG_HFS_2
837 
838 #define MEI_CFG_PCH8_HFS                        \
839 	.fw_status.count = 6,                   \
840 	.fw_status.status[0] = PCI_CFG_HFS_1,   \
841 	.fw_status.status[1] = PCI_CFG_HFS_2,   \
842 	.fw_status.status[2] = PCI_CFG_HFS_3,   \
843 	.fw_status.status[3] = PCI_CFG_HFS_4,   \
844 	.fw_status.status[4] = PCI_CFG_HFS_5,   \
845 	.fw_status.status[5] = PCI_CFG_HFS_6
846 
847 /* ICH Legacy devices */
848 const struct mei_cfg mei_me_legacy_cfg = {
849 	MEI_CFG_LEGACY_HFS,
850 };
851 
852 /* ICH devices */
853 const struct mei_cfg mei_me_ich_cfg = {
854 	MEI_CFG_ICH_HFS,
855 };
856 
857 /* PCH devices */
858 const struct mei_cfg mei_me_pch_cfg = {
859 	MEI_CFG_PCH_HFS,
860 };
861 
862 
863 /* PCH Cougar Point and Patsburg with quirk for Node Manager exclusion */
864 const struct mei_cfg mei_me_pch_cpt_pbg_cfg = {
865 	MEI_CFG_PCH_HFS,
866 	MEI_CFG_FW_NM,
867 };
868 
869 /* PCH8 Lynx Point and newer devices */
870 const struct mei_cfg mei_me_pch8_cfg = {
871 	MEI_CFG_PCH8_HFS,
872 };
873 
874 /* PCH8 Lynx Point with quirk for SPS Firmware exclusion */
875 const struct mei_cfg mei_me_pch8_sps_cfg = {
876 	MEI_CFG_PCH8_HFS,
877 	MEI_CFG_FW_SPS,
878 };
879 
880 /**
881  * mei_me_dev_init - allocates and initializes the mei device structure
882  *
883  * @pdev: The pci device structure
884  * @cfg: per device generation config
885  *
886  * Return: The mei_device_device pointer on success, NULL on failure.
887  */
888 struct mei_device *mei_me_dev_init(struct pci_dev *pdev,
889 				   const struct mei_cfg *cfg)
890 {
891 	struct mei_device *dev;
892 	struct mei_me_hw *hw;
893 
894 	dev = kzalloc(sizeof(struct mei_device) +
895 			 sizeof(struct mei_me_hw), GFP_KERNEL);
896 	if (!dev)
897 		return NULL;
898 	hw = to_me_hw(dev);
899 
900 	mei_device_init(dev, &pdev->dev, &mei_me_hw_ops);
901 	hw->cfg = cfg;
902 	return dev;
903 }
904 
905