xref: /linux/drivers/misc/mei/hw-me.c (revision b85d45947951d23cb22d90caecf4c1eb81342c96)
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_CSR_IS_MASK;
138 	mei_hcsr_write(dev, reg);
139 }
140 
141 /**
142  * mei_me_d0i3c_read - Reads 32bit data from the D0I3C register
143  *
144  * @dev: the device structure
145  *
146  * Return: H_D0I3C register value (u32)
147  */
148 static inline u32 mei_me_d0i3c_read(const struct mei_device *dev)
149 {
150 	u32 reg;
151 
152 	reg = mei_me_reg_read(to_me_hw(dev), H_D0I3C);
153 	trace_mei_reg_read(dev->dev, "H_D0I3C", H_CSR, reg);
154 
155 	return reg;
156 }
157 
158 /**
159  * mei_me_d0i3c_write - writes H_D0I3C register to device
160  *
161  * @dev: the device structure
162  * @reg: new register value
163  */
164 static inline void mei_me_d0i3c_write(struct mei_device *dev, u32 reg)
165 {
166 	trace_mei_reg_write(dev->dev, "H_D0I3C", H_CSR, reg);
167 	mei_me_reg_write(to_me_hw(dev), H_D0I3C, reg);
168 }
169 
170 /**
171  * mei_me_fw_status - read fw status register from pci config space
172  *
173  * @dev: mei device
174  * @fw_status: fw status register values
175  *
176  * Return: 0 on success, error otherwise
177  */
178 static int mei_me_fw_status(struct mei_device *dev,
179 			    struct mei_fw_status *fw_status)
180 {
181 	struct pci_dev *pdev = to_pci_dev(dev->dev);
182 	struct mei_me_hw *hw = to_me_hw(dev);
183 	const struct mei_fw_status *fw_src = &hw->cfg->fw_status;
184 	int ret;
185 	int i;
186 
187 	if (!fw_status)
188 		return -EINVAL;
189 
190 	fw_status->count = fw_src->count;
191 	for (i = 0; i < fw_src->count && i < MEI_FW_STATUS_MAX; i++) {
192 		ret = pci_read_config_dword(pdev,
193 			fw_src->status[i], &fw_status->status[i]);
194 		if (ret)
195 			return ret;
196 	}
197 
198 	return 0;
199 }
200 
201 /**
202  * mei_me_hw_config - configure hw dependent settings
203  *
204  * @dev: mei device
205  */
206 static void mei_me_hw_config(struct mei_device *dev)
207 {
208 	struct pci_dev *pdev = to_pci_dev(dev->dev);
209 	struct mei_me_hw *hw = to_me_hw(dev);
210 	u32 hcsr, reg;
211 
212 	/* Doesn't change in runtime */
213 	hcsr = mei_hcsr_read(dev);
214 	dev->hbuf_depth = (hcsr & H_CBD) >> 24;
215 
216 	reg = 0;
217 	pci_read_config_dword(pdev, PCI_CFG_HFS_1, &reg);
218 	hw->d0i3_supported =
219 		((reg & PCI_CFG_HFS_1_D0I3_MSK) == PCI_CFG_HFS_1_D0I3_MSK);
220 
221 	hw->pg_state = MEI_PG_OFF;
222 	if (hw->d0i3_supported) {
223 		reg = mei_me_d0i3c_read(dev);
224 		if (reg & H_D0I3C_I3)
225 			hw->pg_state = MEI_PG_ON;
226 	}
227 }
228 
229 /**
230  * mei_me_pg_state  - translate internal pg state
231  *   to the mei power gating state
232  *
233  * @dev:  mei device
234  *
235  * Return: MEI_PG_OFF if aliveness is on and MEI_PG_ON otherwise
236  */
237 static inline enum mei_pg_state mei_me_pg_state(struct mei_device *dev)
238 {
239 	struct mei_me_hw *hw = to_me_hw(dev);
240 
241 	return hw->pg_state;
242 }
243 
244 /**
245  * mei_me_intr_clear - clear and stop interrupts
246  *
247  * @dev: the device structure
248  */
249 static void mei_me_intr_clear(struct mei_device *dev)
250 {
251 	u32 hcsr = mei_hcsr_read(dev);
252 
253 	if (hcsr & H_CSR_IS_MASK)
254 		mei_hcsr_write(dev, hcsr);
255 }
256 /**
257  * mei_me_intr_enable - enables mei device interrupts
258  *
259  * @dev: the device structure
260  */
261 static void mei_me_intr_enable(struct mei_device *dev)
262 {
263 	u32 hcsr = mei_hcsr_read(dev);
264 
265 	hcsr |= H_CSR_IE_MASK;
266 	mei_hcsr_set(dev, hcsr);
267 }
268 
269 /**
270  * mei_me_intr_disable - disables mei device interrupts
271  *
272  * @dev: the device structure
273  */
274 static void mei_me_intr_disable(struct mei_device *dev)
275 {
276 	u32 hcsr = mei_hcsr_read(dev);
277 
278 	hcsr  &= ~H_CSR_IE_MASK;
279 	mei_hcsr_set(dev, hcsr);
280 }
281 
282 /**
283  * mei_me_hw_reset_release - release device from the reset
284  *
285  * @dev: the device structure
286  */
287 static void mei_me_hw_reset_release(struct mei_device *dev)
288 {
289 	u32 hcsr = mei_hcsr_read(dev);
290 
291 	hcsr |= H_IG;
292 	hcsr &= ~H_RST;
293 	mei_hcsr_set(dev, hcsr);
294 
295 	/* complete this write before we set host ready on another CPU */
296 	mmiowb();
297 }
298 
299 /**
300  * mei_me_host_set_ready - enable device
301  *
302  * @dev: mei device
303  */
304 static void mei_me_host_set_ready(struct mei_device *dev)
305 {
306 	u32 hcsr = mei_hcsr_read(dev);
307 
308 	hcsr |= H_CSR_IE_MASK | H_IG | H_RDY;
309 	mei_hcsr_set(dev, hcsr);
310 }
311 
312 /**
313  * mei_me_host_is_ready - check whether the host has turned ready
314  *
315  * @dev: mei device
316  * Return: bool
317  */
318 static bool mei_me_host_is_ready(struct mei_device *dev)
319 {
320 	u32 hcsr = mei_hcsr_read(dev);
321 
322 	return (hcsr & H_RDY) == H_RDY;
323 }
324 
325 /**
326  * mei_me_hw_is_ready - check whether the me(hw) has turned ready
327  *
328  * @dev: mei device
329  * Return: bool
330  */
331 static bool mei_me_hw_is_ready(struct mei_device *dev)
332 {
333 	u32 mecsr = mei_me_mecsr_read(dev);
334 
335 	return (mecsr & ME_RDY_HRA) == ME_RDY_HRA;
336 }
337 
338 /**
339  * mei_me_hw_ready_wait - wait until the me(hw) has turned ready
340  *  or timeout is reached
341  *
342  * @dev: mei device
343  * Return: 0 on success, error otherwise
344  */
345 static int mei_me_hw_ready_wait(struct mei_device *dev)
346 {
347 	mutex_unlock(&dev->device_lock);
348 	wait_event_timeout(dev->wait_hw_ready,
349 			dev->recvd_hw_ready,
350 			mei_secs_to_jiffies(MEI_HW_READY_TIMEOUT));
351 	mutex_lock(&dev->device_lock);
352 	if (!dev->recvd_hw_ready) {
353 		dev_err(dev->dev, "wait hw ready failed\n");
354 		return -ETIME;
355 	}
356 
357 	mei_me_hw_reset_release(dev);
358 	dev->recvd_hw_ready = false;
359 	return 0;
360 }
361 
362 /**
363  * mei_me_hw_start - hw start routine
364  *
365  * @dev: mei device
366  * Return: 0 on success, error otherwise
367  */
368 static int mei_me_hw_start(struct mei_device *dev)
369 {
370 	int ret = mei_me_hw_ready_wait(dev);
371 
372 	if (ret)
373 		return ret;
374 	dev_dbg(dev->dev, "hw is ready\n");
375 
376 	mei_me_host_set_ready(dev);
377 	return ret;
378 }
379 
380 
381 /**
382  * mei_hbuf_filled_slots - gets number of device filled buffer slots
383  *
384  * @dev: the device structure
385  *
386  * Return: number of filled slots
387  */
388 static unsigned char mei_hbuf_filled_slots(struct mei_device *dev)
389 {
390 	u32 hcsr;
391 	char read_ptr, write_ptr;
392 
393 	hcsr = mei_hcsr_read(dev);
394 
395 	read_ptr = (char) ((hcsr & H_CBRP) >> 8);
396 	write_ptr = (char) ((hcsr & H_CBWP) >> 16);
397 
398 	return (unsigned char) (write_ptr - read_ptr);
399 }
400 
401 /**
402  * mei_me_hbuf_is_empty - checks if host buffer is empty.
403  *
404  * @dev: the device structure
405  *
406  * Return: true if empty, false - otherwise.
407  */
408 static bool mei_me_hbuf_is_empty(struct mei_device *dev)
409 {
410 	return mei_hbuf_filled_slots(dev) == 0;
411 }
412 
413 /**
414  * mei_me_hbuf_empty_slots - counts write empty slots.
415  *
416  * @dev: the device structure
417  *
418  * Return: -EOVERFLOW if overflow, otherwise empty slots count
419  */
420 static int mei_me_hbuf_empty_slots(struct mei_device *dev)
421 {
422 	unsigned char filled_slots, empty_slots;
423 
424 	filled_slots = mei_hbuf_filled_slots(dev);
425 	empty_slots = dev->hbuf_depth - filled_slots;
426 
427 	/* check for overflow */
428 	if (filled_slots > dev->hbuf_depth)
429 		return -EOVERFLOW;
430 
431 	return empty_slots;
432 }
433 
434 /**
435  * mei_me_hbuf_max_len - returns size of hw buffer.
436  *
437  * @dev: the device structure
438  *
439  * Return: size of hw buffer in bytes
440  */
441 static size_t mei_me_hbuf_max_len(const struct mei_device *dev)
442 {
443 	return dev->hbuf_depth * sizeof(u32) - sizeof(struct mei_msg_hdr);
444 }
445 
446 
447 /**
448  * mei_me_write_message - writes a message to mei device.
449  *
450  * @dev: the device structure
451  * @header: mei HECI header of message
452  * @buf: message payload will be written
453  *
454  * Return: -EIO if write has failed
455  */
456 static int mei_me_write_message(struct mei_device *dev,
457 			struct mei_msg_hdr *header,
458 			unsigned char *buf)
459 {
460 	unsigned long rem;
461 	unsigned long length = header->length;
462 	u32 *reg_buf = (u32 *)buf;
463 	u32 hcsr;
464 	u32 dw_cnt;
465 	int i;
466 	int empty_slots;
467 
468 	dev_dbg(dev->dev, MEI_HDR_FMT, MEI_HDR_PRM(header));
469 
470 	empty_slots = mei_hbuf_empty_slots(dev);
471 	dev_dbg(dev->dev, "empty slots = %hu.\n", empty_slots);
472 
473 	dw_cnt = mei_data2slots(length);
474 	if (empty_slots < 0 || dw_cnt > empty_slots)
475 		return -EMSGSIZE;
476 
477 	mei_me_hcbww_write(dev, *((u32 *) header));
478 
479 	for (i = 0; i < length / 4; i++)
480 		mei_me_hcbww_write(dev, reg_buf[i]);
481 
482 	rem = length & 0x3;
483 	if (rem > 0) {
484 		u32 reg = 0;
485 
486 		memcpy(&reg, &buf[length - rem], rem);
487 		mei_me_hcbww_write(dev, reg);
488 	}
489 
490 	hcsr = mei_hcsr_read(dev) | H_IG;
491 	mei_hcsr_set(dev, hcsr);
492 	if (!mei_me_hw_is_ready(dev))
493 		return -EIO;
494 
495 	return 0;
496 }
497 
498 /**
499  * mei_me_count_full_read_slots - counts read full slots.
500  *
501  * @dev: the device structure
502  *
503  * Return: -EOVERFLOW if overflow, otherwise filled slots count
504  */
505 static int mei_me_count_full_read_slots(struct mei_device *dev)
506 {
507 	u32 me_csr;
508 	char read_ptr, write_ptr;
509 	unsigned char buffer_depth, filled_slots;
510 
511 	me_csr = mei_me_mecsr_read(dev);
512 	buffer_depth = (unsigned char)((me_csr & ME_CBD_HRA) >> 24);
513 	read_ptr = (char) ((me_csr & ME_CBRP_HRA) >> 8);
514 	write_ptr = (char) ((me_csr & ME_CBWP_HRA) >> 16);
515 	filled_slots = (unsigned char) (write_ptr - read_ptr);
516 
517 	/* check for overflow */
518 	if (filled_slots > buffer_depth)
519 		return -EOVERFLOW;
520 
521 	dev_dbg(dev->dev, "filled_slots =%08x\n", filled_slots);
522 	return (int)filled_slots;
523 }
524 
525 /**
526  * mei_me_read_slots - reads a message from mei device.
527  *
528  * @dev: the device structure
529  * @buffer: message buffer will be written
530  * @buffer_length: message size will be read
531  *
532  * Return: always 0
533  */
534 static int mei_me_read_slots(struct mei_device *dev, unsigned char *buffer,
535 		    unsigned long buffer_length)
536 {
537 	u32 *reg_buf = (u32 *)buffer;
538 	u32 hcsr;
539 
540 	for (; buffer_length >= sizeof(u32); buffer_length -= sizeof(u32))
541 		*reg_buf++ = mei_me_mecbrw_read(dev);
542 
543 	if (buffer_length > 0) {
544 		u32 reg = mei_me_mecbrw_read(dev);
545 
546 		memcpy(reg_buf, &reg, buffer_length);
547 	}
548 
549 	hcsr = mei_hcsr_read(dev) | H_IG;
550 	mei_hcsr_set(dev, hcsr);
551 	return 0;
552 }
553 
554 /**
555  * mei_me_pg_set - write pg enter register
556  *
557  * @dev: the device structure
558  */
559 static void mei_me_pg_set(struct mei_device *dev)
560 {
561 	struct mei_me_hw *hw = to_me_hw(dev);
562 	u32 reg;
563 
564 	reg = mei_me_reg_read(hw, H_HPG_CSR);
565 	trace_mei_reg_read(dev->dev, "H_HPG_CSR", H_HPG_CSR, reg);
566 
567 	reg |= H_HPG_CSR_PGI;
568 
569 	trace_mei_reg_write(dev->dev, "H_HPG_CSR", H_HPG_CSR, reg);
570 	mei_me_reg_write(hw, H_HPG_CSR, reg);
571 }
572 
573 /**
574  * mei_me_pg_unset - write pg exit register
575  *
576  * @dev: the device structure
577  */
578 static void mei_me_pg_unset(struct mei_device *dev)
579 {
580 	struct mei_me_hw *hw = to_me_hw(dev);
581 	u32 reg;
582 
583 	reg = mei_me_reg_read(hw, H_HPG_CSR);
584 	trace_mei_reg_read(dev->dev, "H_HPG_CSR", H_HPG_CSR, reg);
585 
586 	WARN(!(reg & H_HPG_CSR_PGI), "PGI is not set\n");
587 
588 	reg |= H_HPG_CSR_PGIHEXR;
589 
590 	trace_mei_reg_write(dev->dev, "H_HPG_CSR", H_HPG_CSR, reg);
591 	mei_me_reg_write(hw, H_HPG_CSR, reg);
592 }
593 
594 /**
595  * mei_me_pg_legacy_enter_sync - perform legacy pg entry procedure
596  *
597  * @dev: the device structure
598  *
599  * Return: 0 on success an error code otherwise
600  */
601 static int mei_me_pg_legacy_enter_sync(struct mei_device *dev)
602 {
603 	struct mei_me_hw *hw = to_me_hw(dev);
604 	unsigned long timeout = mei_secs_to_jiffies(MEI_PGI_TIMEOUT);
605 	int ret;
606 
607 	dev->pg_event = MEI_PG_EVENT_WAIT;
608 
609 	ret = mei_hbm_pg(dev, MEI_PG_ISOLATION_ENTRY_REQ_CMD);
610 	if (ret)
611 		return ret;
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 	if (dev->pg_event == MEI_PG_EVENT_RECEIVED) {
619 		mei_me_pg_set(dev);
620 		ret = 0;
621 	} else {
622 		ret = -ETIME;
623 	}
624 
625 	dev->pg_event = MEI_PG_EVENT_IDLE;
626 	hw->pg_state = MEI_PG_ON;
627 
628 	return ret;
629 }
630 
631 /**
632  * mei_me_pg_legacy_exit_sync - perform legacy pg exit procedure
633  *
634  * @dev: the device structure
635  *
636  * Return: 0 on success an error code otherwise
637  */
638 static int mei_me_pg_legacy_exit_sync(struct mei_device *dev)
639 {
640 	struct mei_me_hw *hw = to_me_hw(dev);
641 	unsigned long timeout = mei_secs_to_jiffies(MEI_PGI_TIMEOUT);
642 	int ret;
643 
644 	if (dev->pg_event == MEI_PG_EVENT_RECEIVED)
645 		goto reply;
646 
647 	dev->pg_event = MEI_PG_EVENT_WAIT;
648 
649 	mei_me_pg_unset(dev);
650 
651 	mutex_unlock(&dev->device_lock);
652 	wait_event_timeout(dev->wait_pg,
653 		dev->pg_event == MEI_PG_EVENT_RECEIVED, timeout);
654 	mutex_lock(&dev->device_lock);
655 
656 reply:
657 	if (dev->pg_event != MEI_PG_EVENT_RECEIVED) {
658 		ret = -ETIME;
659 		goto out;
660 	}
661 
662 	dev->pg_event = MEI_PG_EVENT_INTR_WAIT;
663 	ret = mei_hbm_pg(dev, MEI_PG_ISOLATION_EXIT_RES_CMD);
664 	if (ret)
665 		return ret;
666 
667 	mutex_unlock(&dev->device_lock);
668 	wait_event_timeout(dev->wait_pg,
669 		dev->pg_event == MEI_PG_EVENT_INTR_RECEIVED, timeout);
670 	mutex_lock(&dev->device_lock);
671 
672 	if (dev->pg_event == MEI_PG_EVENT_INTR_RECEIVED)
673 		ret = 0;
674 	else
675 		ret = -ETIME;
676 
677 out:
678 	dev->pg_event = MEI_PG_EVENT_IDLE;
679 	hw->pg_state = MEI_PG_OFF;
680 
681 	return ret;
682 }
683 
684 /**
685  * mei_me_pg_in_transition - is device now in pg transition
686  *
687  * @dev: the device structure
688  *
689  * Return: true if in pg transition, false otherwise
690  */
691 static bool mei_me_pg_in_transition(struct mei_device *dev)
692 {
693 	return dev->pg_event >= MEI_PG_EVENT_WAIT &&
694 	       dev->pg_event <= MEI_PG_EVENT_INTR_WAIT;
695 }
696 
697 /**
698  * mei_me_pg_is_enabled - detect if PG is supported by HW
699  *
700  * @dev: the device structure
701  *
702  * Return: true is pg supported, false otherwise
703  */
704 static bool mei_me_pg_is_enabled(struct mei_device *dev)
705 {
706 	struct mei_me_hw *hw = to_me_hw(dev);
707 	u32 reg = mei_me_mecsr_read(dev);
708 
709 	if (hw->d0i3_supported)
710 		return true;
711 
712 	if ((reg & ME_PGIC_HRA) == 0)
713 		goto notsupported;
714 
715 	if (!dev->hbm_f_pg_supported)
716 		goto notsupported;
717 
718 	return true;
719 
720 notsupported:
721 	dev_dbg(dev->dev, "pg: not supported: d0i3 = %d HGP = %d hbm version %d.%d ?= %d.%d\n",
722 		hw->d0i3_supported,
723 		!!(reg & ME_PGIC_HRA),
724 		dev->version.major_version,
725 		dev->version.minor_version,
726 		HBM_MAJOR_VERSION_PGI,
727 		HBM_MINOR_VERSION_PGI);
728 
729 	return false;
730 }
731 
732 /**
733  * mei_me_d0i3_set - write d0i3 register bit on mei device.
734  *
735  * @dev: the device structure
736  * @intr: ask for interrupt
737  *
738  * Return: D0I3C register value
739  */
740 static u32 mei_me_d0i3_set(struct mei_device *dev, bool intr)
741 {
742 	u32 reg = mei_me_d0i3c_read(dev);
743 
744 	reg |= H_D0I3C_I3;
745 	if (intr)
746 		reg |= H_D0I3C_IR;
747 	else
748 		reg &= ~H_D0I3C_IR;
749 	mei_me_d0i3c_write(dev, reg);
750 	/* read it to ensure HW consistency */
751 	reg = mei_me_d0i3c_read(dev);
752 	return reg;
753 }
754 
755 /**
756  * mei_me_d0i3_unset - clean d0i3 register bit on mei device.
757  *
758  * @dev: the device structure
759  *
760  * Return: D0I3C register value
761  */
762 static u32 mei_me_d0i3_unset(struct mei_device *dev)
763 {
764 	u32 reg = mei_me_d0i3c_read(dev);
765 
766 	reg &= ~H_D0I3C_I3;
767 	reg |= H_D0I3C_IR;
768 	mei_me_d0i3c_write(dev, reg);
769 	/* read it to ensure HW consistency */
770 	reg = mei_me_d0i3c_read(dev);
771 	return reg;
772 }
773 
774 /**
775  * mei_me_d0i3_enter_sync - perform d0i3 entry procedure
776  *
777  * @dev: the device structure
778  *
779  * Return: 0 on success an error code otherwise
780  */
781 static int mei_me_d0i3_enter_sync(struct mei_device *dev)
782 {
783 	struct mei_me_hw *hw = to_me_hw(dev);
784 	unsigned long d0i3_timeout = mei_secs_to_jiffies(MEI_D0I3_TIMEOUT);
785 	unsigned long pgi_timeout = mei_secs_to_jiffies(MEI_PGI_TIMEOUT);
786 	int ret;
787 	u32 reg;
788 
789 	reg = mei_me_d0i3c_read(dev);
790 	if (reg & H_D0I3C_I3) {
791 		/* we are in d0i3, nothing to do */
792 		dev_dbg(dev->dev, "d0i3 set not needed\n");
793 		ret = 0;
794 		goto on;
795 	}
796 
797 	/* PGI entry procedure */
798 	dev->pg_event = MEI_PG_EVENT_WAIT;
799 
800 	ret = mei_hbm_pg(dev, MEI_PG_ISOLATION_ENTRY_REQ_CMD);
801 	if (ret)
802 		/* FIXME: should we reset here? */
803 		goto out;
804 
805 	mutex_unlock(&dev->device_lock);
806 	wait_event_timeout(dev->wait_pg,
807 		dev->pg_event == MEI_PG_EVENT_RECEIVED, pgi_timeout);
808 	mutex_lock(&dev->device_lock);
809 
810 	if (dev->pg_event != MEI_PG_EVENT_RECEIVED) {
811 		ret = -ETIME;
812 		goto out;
813 	}
814 	/* end PGI entry procedure */
815 
816 	dev->pg_event = MEI_PG_EVENT_INTR_WAIT;
817 
818 	reg = mei_me_d0i3_set(dev, true);
819 	if (!(reg & H_D0I3C_CIP)) {
820 		dev_dbg(dev->dev, "d0i3 enter wait not needed\n");
821 		ret = 0;
822 		goto on;
823 	}
824 
825 	mutex_unlock(&dev->device_lock);
826 	wait_event_timeout(dev->wait_pg,
827 		dev->pg_event == MEI_PG_EVENT_INTR_RECEIVED, d0i3_timeout);
828 	mutex_lock(&dev->device_lock);
829 
830 	if (dev->pg_event != MEI_PG_EVENT_INTR_RECEIVED) {
831 		reg = mei_me_d0i3c_read(dev);
832 		if (!(reg & H_D0I3C_I3)) {
833 			ret = -ETIME;
834 			goto out;
835 		}
836 	}
837 
838 	ret = 0;
839 on:
840 	hw->pg_state = MEI_PG_ON;
841 out:
842 	dev->pg_event = MEI_PG_EVENT_IDLE;
843 	dev_dbg(dev->dev, "d0i3 enter ret = %d\n", ret);
844 	return ret;
845 }
846 
847 /**
848  * mei_me_d0i3_enter - perform d0i3 entry procedure
849  *   no hbm PG handshake
850  *   no waiting for confirmation; runs with interrupts
851  *   disabled
852  *
853  * @dev: the device structure
854  *
855  * Return: 0 on success an error code otherwise
856  */
857 static int mei_me_d0i3_enter(struct mei_device *dev)
858 {
859 	struct mei_me_hw *hw = to_me_hw(dev);
860 	u32 reg;
861 
862 	reg = mei_me_d0i3c_read(dev);
863 	if (reg & H_D0I3C_I3) {
864 		/* we are in d0i3, nothing to do */
865 		dev_dbg(dev->dev, "already d0i3 : set not needed\n");
866 		goto on;
867 	}
868 
869 	mei_me_d0i3_set(dev, false);
870 on:
871 	hw->pg_state = MEI_PG_ON;
872 	dev->pg_event = MEI_PG_EVENT_IDLE;
873 	dev_dbg(dev->dev, "d0i3 enter\n");
874 	return 0;
875 }
876 
877 /**
878  * mei_me_d0i3_exit_sync - perform d0i3 exit procedure
879  *
880  * @dev: the device structure
881  *
882  * Return: 0 on success an error code otherwise
883  */
884 static int mei_me_d0i3_exit_sync(struct mei_device *dev)
885 {
886 	struct mei_me_hw *hw = to_me_hw(dev);
887 	unsigned long timeout = mei_secs_to_jiffies(MEI_D0I3_TIMEOUT);
888 	int ret;
889 	u32 reg;
890 
891 	dev->pg_event = MEI_PG_EVENT_INTR_WAIT;
892 
893 	reg = mei_me_d0i3c_read(dev);
894 	if (!(reg & H_D0I3C_I3)) {
895 		/* we are not in d0i3, nothing to do */
896 		dev_dbg(dev->dev, "d0i3 exit not needed\n");
897 		ret = 0;
898 		goto off;
899 	}
900 
901 	reg = mei_me_d0i3_unset(dev);
902 	if (!(reg & H_D0I3C_CIP)) {
903 		dev_dbg(dev->dev, "d0i3 exit wait not needed\n");
904 		ret = 0;
905 		goto off;
906 	}
907 
908 	mutex_unlock(&dev->device_lock);
909 	wait_event_timeout(dev->wait_pg,
910 		dev->pg_event == MEI_PG_EVENT_INTR_RECEIVED, timeout);
911 	mutex_lock(&dev->device_lock);
912 
913 	if (dev->pg_event != MEI_PG_EVENT_INTR_RECEIVED) {
914 		reg = mei_me_d0i3c_read(dev);
915 		if (reg & H_D0I3C_I3) {
916 			ret = -ETIME;
917 			goto out;
918 		}
919 	}
920 
921 	ret = 0;
922 off:
923 	hw->pg_state = MEI_PG_OFF;
924 out:
925 	dev->pg_event = MEI_PG_EVENT_IDLE;
926 
927 	dev_dbg(dev->dev, "d0i3 exit ret = %d\n", ret);
928 	return ret;
929 }
930 
931 /**
932  * mei_me_pg_legacy_intr - perform legacy pg processing
933  *			   in interrupt thread handler
934  *
935  * @dev: the device structure
936  */
937 static void mei_me_pg_legacy_intr(struct mei_device *dev)
938 {
939 	struct mei_me_hw *hw = to_me_hw(dev);
940 
941 	if (dev->pg_event != MEI_PG_EVENT_INTR_WAIT)
942 		return;
943 
944 	dev->pg_event = MEI_PG_EVENT_INTR_RECEIVED;
945 	hw->pg_state = MEI_PG_OFF;
946 	if (waitqueue_active(&dev->wait_pg))
947 		wake_up(&dev->wait_pg);
948 }
949 
950 /**
951  * mei_me_d0i3_intr - perform d0i3 processing in interrupt thread handler
952  *
953  * @dev: the device structure
954  */
955 static void mei_me_d0i3_intr(struct mei_device *dev)
956 {
957 	struct mei_me_hw *hw = to_me_hw(dev);
958 
959 	if (dev->pg_event == MEI_PG_EVENT_INTR_WAIT &&
960 	    (hw->intr_source & H_D0I3C_IS)) {
961 		dev->pg_event = MEI_PG_EVENT_INTR_RECEIVED;
962 		if (hw->pg_state == MEI_PG_ON) {
963 			hw->pg_state = MEI_PG_OFF;
964 			if (dev->hbm_state != MEI_HBM_IDLE) {
965 				/*
966 				 * force H_RDY because it could be
967 				 * wiped off during PG
968 				 */
969 				dev_dbg(dev->dev, "d0i3 set host ready\n");
970 				mei_me_host_set_ready(dev);
971 			}
972 		} else {
973 			hw->pg_state = MEI_PG_ON;
974 		}
975 
976 		wake_up(&dev->wait_pg);
977 	}
978 
979 	if (hw->pg_state == MEI_PG_ON && (hw->intr_source & H_IS)) {
980 		/*
981 		 * HW sent some data and we are in D0i3, so
982 		 * we got here because of HW initiated exit from D0i3.
983 		 * Start runtime pm resume sequence to exit low power state.
984 		 */
985 		dev_dbg(dev->dev, "d0i3 want resume\n");
986 		mei_hbm_pg_resume(dev);
987 	}
988 }
989 
990 /**
991  * mei_me_pg_intr - perform pg processing in interrupt thread handler
992  *
993  * @dev: the device structure
994  */
995 static void mei_me_pg_intr(struct mei_device *dev)
996 {
997 	struct mei_me_hw *hw = to_me_hw(dev);
998 
999 	if (hw->d0i3_supported)
1000 		mei_me_d0i3_intr(dev);
1001 	else
1002 		mei_me_pg_legacy_intr(dev);
1003 }
1004 
1005 /**
1006  * mei_me_pg_enter_sync - perform runtime pm entry procedure
1007  *
1008  * @dev: the device structure
1009  *
1010  * Return: 0 on success an error code otherwise
1011  */
1012 int mei_me_pg_enter_sync(struct mei_device *dev)
1013 {
1014 	struct mei_me_hw *hw = to_me_hw(dev);
1015 
1016 	if (hw->d0i3_supported)
1017 		return mei_me_d0i3_enter_sync(dev);
1018 	else
1019 		return mei_me_pg_legacy_enter_sync(dev);
1020 }
1021 
1022 /**
1023  * mei_me_pg_exit_sync - perform runtime pm exit procedure
1024  *
1025  * @dev: the device structure
1026  *
1027  * Return: 0 on success an error code otherwise
1028  */
1029 int mei_me_pg_exit_sync(struct mei_device *dev)
1030 {
1031 	struct mei_me_hw *hw = to_me_hw(dev);
1032 
1033 	if (hw->d0i3_supported)
1034 		return mei_me_d0i3_exit_sync(dev);
1035 	else
1036 		return mei_me_pg_legacy_exit_sync(dev);
1037 }
1038 
1039 /**
1040  * mei_me_hw_reset - resets fw via mei csr register.
1041  *
1042  * @dev: the device structure
1043  * @intr_enable: if interrupt should be enabled after reset.
1044  *
1045  * Return: 0 on success an error code otherwise
1046  */
1047 static int mei_me_hw_reset(struct mei_device *dev, bool intr_enable)
1048 {
1049 	struct mei_me_hw *hw = to_me_hw(dev);
1050 	int ret;
1051 	u32 hcsr;
1052 
1053 	if (intr_enable) {
1054 		mei_me_intr_enable(dev);
1055 		if (hw->d0i3_supported) {
1056 			ret = mei_me_d0i3_exit_sync(dev);
1057 			if (ret)
1058 				return ret;
1059 		}
1060 	}
1061 
1062 	hcsr = mei_hcsr_read(dev);
1063 	/* H_RST may be found lit before reset is started,
1064 	 * for example if preceding reset flow hasn't completed.
1065 	 * In that case asserting H_RST will be ignored, therefore
1066 	 * we need to clean H_RST bit to start a successful reset sequence.
1067 	 */
1068 	if ((hcsr & H_RST) == H_RST) {
1069 		dev_warn(dev->dev, "H_RST is set = 0x%08X", hcsr);
1070 		hcsr &= ~H_RST;
1071 		mei_hcsr_set(dev, hcsr);
1072 		hcsr = mei_hcsr_read(dev);
1073 	}
1074 
1075 	hcsr |= H_RST | H_IG | H_CSR_IS_MASK;
1076 
1077 	if (!intr_enable)
1078 		hcsr &= ~H_CSR_IE_MASK;
1079 
1080 	dev->recvd_hw_ready = false;
1081 	mei_hcsr_write(dev, hcsr);
1082 
1083 	/*
1084 	 * Host reads the H_CSR once to ensure that the
1085 	 * posted write to H_CSR completes.
1086 	 */
1087 	hcsr = mei_hcsr_read(dev);
1088 
1089 	if ((hcsr & H_RST) == 0)
1090 		dev_warn(dev->dev, "H_RST is not set = 0x%08X", hcsr);
1091 
1092 	if ((hcsr & H_RDY) == H_RDY)
1093 		dev_warn(dev->dev, "H_RDY is not cleared 0x%08X", hcsr);
1094 
1095 	if (!intr_enable) {
1096 		mei_me_hw_reset_release(dev);
1097 		if (hw->d0i3_supported) {
1098 			ret = mei_me_d0i3_enter(dev);
1099 			if (ret)
1100 				return ret;
1101 		}
1102 	}
1103 	return 0;
1104 }
1105 
1106 /**
1107  * mei_me_irq_quick_handler - The ISR of the MEI device
1108  *
1109  * @irq: The irq number
1110  * @dev_id: pointer to the device structure
1111  *
1112  * Return: irqreturn_t
1113  */
1114 irqreturn_t mei_me_irq_quick_handler(int irq, void *dev_id)
1115 {
1116 	struct mei_device *dev = (struct mei_device *)dev_id;
1117 	struct mei_me_hw *hw = to_me_hw(dev);
1118 	u32 hcsr;
1119 
1120 	hcsr = mei_hcsr_read(dev);
1121 	if (!(hcsr & H_CSR_IS_MASK))
1122 		return IRQ_NONE;
1123 
1124 	hw->intr_source = hcsr & H_CSR_IS_MASK;
1125 	dev_dbg(dev->dev, "interrupt source 0x%08X.\n", hw->intr_source);
1126 
1127 	/* clear H_IS and H_D0I3C_IS bits in H_CSR to clear the interrupts */
1128 	mei_hcsr_write(dev, hcsr);
1129 
1130 	return IRQ_WAKE_THREAD;
1131 }
1132 
1133 /**
1134  * mei_me_irq_thread_handler - function called after ISR to handle the interrupt
1135  * processing.
1136  *
1137  * @irq: The irq number
1138  * @dev_id: pointer to the device structure
1139  *
1140  * Return: irqreturn_t
1141  *
1142  */
1143 irqreturn_t mei_me_irq_thread_handler(int irq, void *dev_id)
1144 {
1145 	struct mei_device *dev = (struct mei_device *) dev_id;
1146 	struct mei_cl_cb complete_list;
1147 	s32 slots;
1148 	int rets = 0;
1149 
1150 	dev_dbg(dev->dev, "function called after ISR to handle the interrupt processing.\n");
1151 	/* initialize our complete list */
1152 	mutex_lock(&dev->device_lock);
1153 	mei_io_list_init(&complete_list);
1154 
1155 	/* check if ME wants a reset */
1156 	if (!mei_hw_is_ready(dev) && dev->dev_state != MEI_DEV_RESETTING) {
1157 		dev_warn(dev->dev, "FW not ready: resetting.\n");
1158 		schedule_work(&dev->reset_work);
1159 		goto end;
1160 	}
1161 
1162 	mei_me_pg_intr(dev);
1163 
1164 	/*  check if we need to start the dev */
1165 	if (!mei_host_is_ready(dev)) {
1166 		if (mei_hw_is_ready(dev)) {
1167 			dev_dbg(dev->dev, "we need to start the dev.\n");
1168 			dev->recvd_hw_ready = true;
1169 			wake_up(&dev->wait_hw_ready);
1170 		} else {
1171 			dev_dbg(dev->dev, "Spurious Interrupt\n");
1172 		}
1173 		goto end;
1174 	}
1175 	/* check slots available for reading */
1176 	slots = mei_count_full_read_slots(dev);
1177 	while (slots > 0) {
1178 		dev_dbg(dev->dev, "slots to read = %08x\n", slots);
1179 		rets = mei_irq_read_handler(dev, &complete_list, &slots);
1180 		/* There is a race between ME write and interrupt delivery:
1181 		 * Not all data is always available immediately after the
1182 		 * interrupt, so try to read again on the next interrupt.
1183 		 */
1184 		if (rets == -ENODATA)
1185 			break;
1186 
1187 		if (rets && dev->dev_state != MEI_DEV_RESETTING) {
1188 			dev_err(dev->dev, "mei_irq_read_handler ret = %d.\n",
1189 						rets);
1190 			schedule_work(&dev->reset_work);
1191 			goto end;
1192 		}
1193 	}
1194 
1195 	dev->hbuf_is_ready = mei_hbuf_is_ready(dev);
1196 
1197 	/*
1198 	 * During PG handshake only allowed write is the replay to the
1199 	 * PG exit message, so block calling write function
1200 	 * if the pg event is in PG handshake
1201 	 */
1202 	if (dev->pg_event != MEI_PG_EVENT_WAIT &&
1203 	    dev->pg_event != MEI_PG_EVENT_RECEIVED) {
1204 		rets = mei_irq_write_handler(dev, &complete_list);
1205 		dev->hbuf_is_ready = mei_hbuf_is_ready(dev);
1206 	}
1207 
1208 	mei_irq_compl_handler(dev, &complete_list);
1209 
1210 end:
1211 	dev_dbg(dev->dev, "interrupt thread end ret = %d\n", rets);
1212 	mutex_unlock(&dev->device_lock);
1213 	return IRQ_HANDLED;
1214 }
1215 
1216 static const struct mei_hw_ops mei_me_hw_ops = {
1217 
1218 	.fw_status = mei_me_fw_status,
1219 	.pg_state  = mei_me_pg_state,
1220 
1221 	.host_is_ready = mei_me_host_is_ready,
1222 
1223 	.hw_is_ready = mei_me_hw_is_ready,
1224 	.hw_reset = mei_me_hw_reset,
1225 	.hw_config = mei_me_hw_config,
1226 	.hw_start = mei_me_hw_start,
1227 
1228 	.pg_in_transition = mei_me_pg_in_transition,
1229 	.pg_is_enabled = mei_me_pg_is_enabled,
1230 
1231 	.intr_clear = mei_me_intr_clear,
1232 	.intr_enable = mei_me_intr_enable,
1233 	.intr_disable = mei_me_intr_disable,
1234 
1235 	.hbuf_free_slots = mei_me_hbuf_empty_slots,
1236 	.hbuf_is_ready = mei_me_hbuf_is_empty,
1237 	.hbuf_max_len = mei_me_hbuf_max_len,
1238 
1239 	.write = mei_me_write_message,
1240 
1241 	.rdbuf_full_slots = mei_me_count_full_read_slots,
1242 	.read_hdr = mei_me_mecbrw_read,
1243 	.read = mei_me_read_slots
1244 };
1245 
1246 static bool mei_me_fw_type_nm(struct pci_dev *pdev)
1247 {
1248 	u32 reg;
1249 
1250 	pci_read_config_dword(pdev, PCI_CFG_HFS_2, &reg);
1251 	/* make sure that bit 9 (NM) is up and bit 10 (DM) is down */
1252 	return (reg & 0x600) == 0x200;
1253 }
1254 
1255 #define MEI_CFG_FW_NM                           \
1256 	.quirk_probe = mei_me_fw_type_nm
1257 
1258 static bool mei_me_fw_type_sps(struct pci_dev *pdev)
1259 {
1260 	u32 reg;
1261 	/* Read ME FW Status check for SPS Firmware */
1262 	pci_read_config_dword(pdev, PCI_CFG_HFS_1, &reg);
1263 	/* if bits [19:16] = 15, running SPS Firmware */
1264 	return (reg & 0xf0000) == 0xf0000;
1265 }
1266 
1267 #define MEI_CFG_FW_SPS                           \
1268 	.quirk_probe = mei_me_fw_type_sps
1269 
1270 
1271 #define MEI_CFG_LEGACY_HFS                      \
1272 	.fw_status.count = 0
1273 
1274 #define MEI_CFG_ICH_HFS                        \
1275 	.fw_status.count = 1,                   \
1276 	.fw_status.status[0] = PCI_CFG_HFS_1
1277 
1278 #define MEI_CFG_PCH_HFS                         \
1279 	.fw_status.count = 2,                   \
1280 	.fw_status.status[0] = PCI_CFG_HFS_1,   \
1281 	.fw_status.status[1] = PCI_CFG_HFS_2
1282 
1283 #define MEI_CFG_PCH8_HFS                        \
1284 	.fw_status.count = 6,                   \
1285 	.fw_status.status[0] = PCI_CFG_HFS_1,   \
1286 	.fw_status.status[1] = PCI_CFG_HFS_2,   \
1287 	.fw_status.status[2] = PCI_CFG_HFS_3,   \
1288 	.fw_status.status[3] = PCI_CFG_HFS_4,   \
1289 	.fw_status.status[4] = PCI_CFG_HFS_5,   \
1290 	.fw_status.status[5] = PCI_CFG_HFS_6
1291 
1292 /* ICH Legacy devices */
1293 const struct mei_cfg mei_me_legacy_cfg = {
1294 	MEI_CFG_LEGACY_HFS,
1295 };
1296 
1297 /* ICH devices */
1298 const struct mei_cfg mei_me_ich_cfg = {
1299 	MEI_CFG_ICH_HFS,
1300 };
1301 
1302 /* PCH devices */
1303 const struct mei_cfg mei_me_pch_cfg = {
1304 	MEI_CFG_PCH_HFS,
1305 };
1306 
1307 
1308 /* PCH Cougar Point and Patsburg with quirk for Node Manager exclusion */
1309 const struct mei_cfg mei_me_pch_cpt_pbg_cfg = {
1310 	MEI_CFG_PCH_HFS,
1311 	MEI_CFG_FW_NM,
1312 };
1313 
1314 /* PCH8 Lynx Point and newer devices */
1315 const struct mei_cfg mei_me_pch8_cfg = {
1316 	MEI_CFG_PCH8_HFS,
1317 };
1318 
1319 /* PCH8 Lynx Point with quirk for SPS Firmware exclusion */
1320 const struct mei_cfg mei_me_pch8_sps_cfg = {
1321 	MEI_CFG_PCH8_HFS,
1322 	MEI_CFG_FW_SPS,
1323 };
1324 
1325 /**
1326  * mei_me_dev_init - allocates and initializes the mei device structure
1327  *
1328  * @pdev: The pci device structure
1329  * @cfg: per device generation config
1330  *
1331  * Return: The mei_device_device pointer on success, NULL on failure.
1332  */
1333 struct mei_device *mei_me_dev_init(struct pci_dev *pdev,
1334 				   const struct mei_cfg *cfg)
1335 {
1336 	struct mei_device *dev;
1337 	struct mei_me_hw *hw;
1338 
1339 	dev = kzalloc(sizeof(struct mei_device) +
1340 			 sizeof(struct mei_me_hw), GFP_KERNEL);
1341 	if (!dev)
1342 		return NULL;
1343 	hw = to_me_hw(dev);
1344 
1345 	mei_device_init(dev, &pdev->dev, &mei_me_hw_ops);
1346 	hw->cfg = cfg;
1347 	return dev;
1348 }
1349 
1350