xref: /linux/drivers/misc/mei/hw-txe.c (revision 2a2c74b2efcb1a0ca3fdcb5fbb96ad8de6a29177)
1 /*
2  *
3  * Intel Management Engine Interface (Intel MEI) Linux driver
4  * Copyright (c) 2013-2014, 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 #include <linux/jiffies.h>
19 #include <linux/delay.h>
20 #include <linux/kthread.h>
21 #include <linux/irqreturn.h>
22 
23 #include <linux/mei.h>
24 
25 #include "mei_dev.h"
26 #include "hw-txe.h"
27 #include "client.h"
28 #include "hbm.h"
29 
30 /**
31  * mei_txe_reg_read - Reads 32bit data from the device
32  *
33  * @base_addr: registers base address
34  * @offset: register offset
35  *
36  */
37 static inline u32 mei_txe_reg_read(void __iomem *base_addr,
38 					unsigned long offset)
39 {
40 	return ioread32(base_addr + offset);
41 }
42 
43 /**
44  * mei_txe_reg_write - Writes 32bit data to the device
45  *
46  * @base_addr: registers base address
47  * @offset: register offset
48  * @value: the value to write
49  */
50 static inline void mei_txe_reg_write(void __iomem *base_addr,
51 				unsigned long offset, u32 value)
52 {
53 	iowrite32(value, base_addr + offset);
54 }
55 
56 /**
57  * mei_txe_sec_reg_read_silent - Reads 32bit data from the SeC BAR
58  *
59  * @dev: the device structure
60  * @offset: register offset
61  *
62  * Doesn't check for aliveness while Reads 32bit data from the SeC BAR
63  */
64 static inline u32 mei_txe_sec_reg_read_silent(struct mei_txe_hw *hw,
65 				unsigned long offset)
66 {
67 	return mei_txe_reg_read(hw->mem_addr[SEC_BAR], offset);
68 }
69 
70 /**
71  * mei_txe_sec_reg_read - Reads 32bit data from the SeC BAR
72  *
73  * @dev: the device structure
74  * @offset: register offset
75  *
76  * Reads 32bit data from the SeC BAR and shout loud if aliveness is not set
77  */
78 static inline u32 mei_txe_sec_reg_read(struct mei_txe_hw *hw,
79 				unsigned long offset)
80 {
81 	WARN(!hw->aliveness, "sec read: aliveness not asserted\n");
82 	return mei_txe_sec_reg_read_silent(hw, offset);
83 }
84 /**
85  * mei_txe_sec_reg_write_silent - Writes 32bit data to the SeC BAR
86  *   doesn't check for aliveness
87  *
88  * @dev: the device structure
89  * @offset: register offset
90  * @value: value to write
91  *
92  * Doesn't check for aliveness while writes 32bit data from to the SeC BAR
93  */
94 static inline void mei_txe_sec_reg_write_silent(struct mei_txe_hw *hw,
95 				unsigned long offset, u32 value)
96 {
97 	mei_txe_reg_write(hw->mem_addr[SEC_BAR], offset, value);
98 }
99 
100 /**
101  * mei_txe_sec_reg_write - Writes 32bit data to the SeC BAR
102  *
103  * @dev: the device structure
104  * @offset: register offset
105  * @value: value to write
106  *
107  * Writes 32bit data from the SeC BAR and shout loud if aliveness is not set
108  */
109 static inline void mei_txe_sec_reg_write(struct mei_txe_hw *hw,
110 				unsigned long offset, u32 value)
111 {
112 	WARN(!hw->aliveness, "sec write: aliveness not asserted\n");
113 	mei_txe_sec_reg_write_silent(hw, offset, value);
114 }
115 /**
116  * mei_txe_br_reg_read - Reads 32bit data from the Bridge BAR
117  *
118  * @hw: the device structure
119  * @offset: offset from which to read the data
120  *
121  */
122 static inline u32 mei_txe_br_reg_read(struct mei_txe_hw *hw,
123 				unsigned long offset)
124 {
125 	return mei_txe_reg_read(hw->mem_addr[BRIDGE_BAR], offset);
126 }
127 
128 /**
129  * mei_txe_br_reg_write - Writes 32bit data to the Bridge BAR
130  *
131  * @hw: the device structure
132  * @offset: offset from which to write the data
133  * @value: the byte to write
134  */
135 static inline void mei_txe_br_reg_write(struct mei_txe_hw *hw,
136 				unsigned long offset, u32 value)
137 {
138 	mei_txe_reg_write(hw->mem_addr[BRIDGE_BAR], offset, value);
139 }
140 
141 /**
142  * mei_txe_aliveness_set - request for aliveness change
143  *
144  * @dev: the device structure
145  * @req: requested aliveness value
146  *
147  * Request for aliveness change and returns true if the change is
148  *   really needed and false if aliveness is already
149  *   in the requested state
150  * Requires device lock to be held
151  */
152 static bool mei_txe_aliveness_set(struct mei_device *dev, u32 req)
153 {
154 
155 	struct mei_txe_hw *hw = to_txe_hw(dev);
156 	bool do_req = hw->aliveness != req;
157 
158 	dev_dbg(&dev->pdev->dev, "Aliveness current=%d request=%d\n",
159 				hw->aliveness, req);
160 	if (do_req) {
161 		hw->recvd_aliveness = false;
162 		mei_txe_br_reg_write(hw, SICR_HOST_ALIVENESS_REQ_REG, req);
163 	}
164 	return do_req;
165 }
166 
167 
168 /**
169  * mei_txe_aliveness_req_get - get aliveness requested register value
170  *
171  * @dev: the device structure
172  *
173  * Extract HICR_HOST_ALIVENESS_RESP_ACK bit from
174  * from HICR_HOST_ALIVENESS_REQ register value
175  */
176 static u32 mei_txe_aliveness_req_get(struct mei_device *dev)
177 {
178 	struct mei_txe_hw *hw = to_txe_hw(dev);
179 	u32 reg;
180 	reg = mei_txe_br_reg_read(hw, SICR_HOST_ALIVENESS_REQ_REG);
181 	return reg & SICR_HOST_ALIVENESS_REQ_REQUESTED;
182 }
183 
184 /**
185  * mei_txe_aliveness_get - get aliveness response register value
186  * @dev: the device structure
187  *
188  * Extract HICR_HOST_ALIVENESS_RESP_ACK bit
189  * from HICR_HOST_ALIVENESS_RESP register value
190  */
191 static u32 mei_txe_aliveness_get(struct mei_device *dev)
192 {
193 	struct mei_txe_hw *hw = to_txe_hw(dev);
194 	u32 reg;
195 	reg = mei_txe_br_reg_read(hw, HICR_HOST_ALIVENESS_RESP_REG);
196 	return reg & HICR_HOST_ALIVENESS_RESP_ACK;
197 }
198 
199 /**
200  * mei_txe_aliveness_poll - waits for aliveness to settle
201  *
202  * @dev: the device structure
203  * @expected: expected aliveness value
204  *
205  * Polls for HICR_HOST_ALIVENESS_RESP.ALIVENESS_RESP to be set
206  * returns > 0 if the expected value was received, -ETIME otherwise
207  */
208 static int mei_txe_aliveness_poll(struct mei_device *dev, u32 expected)
209 {
210 	struct mei_txe_hw *hw = to_txe_hw(dev);
211 	int t = 0;
212 
213 	do {
214 		hw->aliveness = mei_txe_aliveness_get(dev);
215 		if (hw->aliveness == expected) {
216 			dev_dbg(&dev->pdev->dev,
217 				"aliveness settled after %d msecs\n", t);
218 			return t;
219 		}
220 		mutex_unlock(&dev->device_lock);
221 		msleep(MSEC_PER_SEC / 5);
222 		mutex_lock(&dev->device_lock);
223 		t += MSEC_PER_SEC / 5;
224 	} while (t < SEC_ALIVENESS_WAIT_TIMEOUT);
225 
226 	dev_err(&dev->pdev->dev, "aliveness timed out\n");
227 	return -ETIME;
228 }
229 
230 /**
231  * mei_txe_aliveness_wait - waits for aliveness to settle
232  *
233  * @dev: the device structure
234  * @expected: expected aliveness value
235  *
236  * Waits for HICR_HOST_ALIVENESS_RESP.ALIVENESS_RESP to be set
237  * returns returns 0 on success and < 0 otherwise
238  */
239 static int mei_txe_aliveness_wait(struct mei_device *dev, u32 expected)
240 {
241 	struct mei_txe_hw *hw = to_txe_hw(dev);
242 	const unsigned long timeout =
243 			msecs_to_jiffies(SEC_ALIVENESS_WAIT_TIMEOUT);
244 	long err;
245 	int ret;
246 
247 	hw->aliveness = mei_txe_aliveness_get(dev);
248 	if (hw->aliveness == expected)
249 		return 0;
250 
251 	mutex_unlock(&dev->device_lock);
252 	err = wait_event_timeout(hw->wait_aliveness,
253 			hw->recvd_aliveness, timeout);
254 	mutex_lock(&dev->device_lock);
255 
256 	hw->aliveness = mei_txe_aliveness_get(dev);
257 	ret = hw->aliveness == expected ? 0 : -ETIME;
258 
259 	if (ret)
260 		dev_err(&dev->pdev->dev, "aliveness timed out");
261 	else
262 		dev_dbg(&dev->pdev->dev, "aliveness settled after %d msecs\n",
263 				jiffies_to_msecs(timeout - err));
264 	hw->recvd_aliveness = false;
265 	return ret;
266 }
267 
268 /**
269  * mei_txe_aliveness_set_sync - sets an wait for aliveness to complete
270  *
271  * @dev: the device structure
272  *
273  * returns returns 0 on success and < 0 otherwise
274  */
275 int mei_txe_aliveness_set_sync(struct mei_device *dev, u32 req)
276 {
277 	if (mei_txe_aliveness_set(dev, req))
278 		return mei_txe_aliveness_wait(dev, req);
279 	return 0;
280 }
281 
282 /**
283  * mei_txe_input_ready_interrupt_enable - sets the Input Ready Interrupt
284  *
285  * @dev: the device structure
286  */
287 static void mei_txe_input_ready_interrupt_enable(struct mei_device *dev)
288 {
289 	struct mei_txe_hw *hw = to_txe_hw(dev);
290 	u32 hintmsk;
291 	/* Enable the SEC_IPC_HOST_INT_MASK_IN_RDY interrupt */
292 	hintmsk = mei_txe_sec_reg_read(hw, SEC_IPC_HOST_INT_MASK_REG);
293 	hintmsk |= SEC_IPC_HOST_INT_MASK_IN_RDY;
294 	mei_txe_sec_reg_write(hw, SEC_IPC_HOST_INT_MASK_REG, hintmsk);
295 }
296 
297 /**
298  * mei_txe_input_doorbell_set
299  *   - Sets bit 0 in SEC_IPC_INPUT_DOORBELL.IPC_INPUT_DOORBELL.
300  * @dev: the device structure
301  */
302 static void mei_txe_input_doorbell_set(struct mei_txe_hw *hw)
303 {
304 	/* Clear the interrupt cause */
305 	clear_bit(TXE_INTR_IN_READY_BIT, &hw->intr_cause);
306 	mei_txe_sec_reg_write(hw, SEC_IPC_INPUT_DOORBELL_REG, 1);
307 }
308 
309 /**
310  * mei_txe_output_ready_set - Sets the SICR_SEC_IPC_OUTPUT_STATUS bit to 1
311  *
312  * @dev: the device structure
313  */
314 static void mei_txe_output_ready_set(struct mei_txe_hw *hw)
315 {
316 	mei_txe_br_reg_write(hw,
317 			SICR_SEC_IPC_OUTPUT_STATUS_REG,
318 			SEC_IPC_OUTPUT_STATUS_RDY);
319 }
320 
321 /**
322  * mei_txe_is_input_ready - check if TXE is ready for receiving data
323  *
324  * @dev: the device structure
325  */
326 static bool mei_txe_is_input_ready(struct mei_device *dev)
327 {
328 	struct mei_txe_hw *hw = to_txe_hw(dev);
329 	u32 status;
330 	status = mei_txe_sec_reg_read(hw, SEC_IPC_INPUT_STATUS_REG);
331 	return !!(SEC_IPC_INPUT_STATUS_RDY & status);
332 }
333 
334 /**
335  * mei_txe_intr_clear - clear all interrupts
336  *
337  * @dev: the device structure
338  */
339 static inline void mei_txe_intr_clear(struct mei_device *dev)
340 {
341 	struct mei_txe_hw *hw = to_txe_hw(dev);
342 	mei_txe_sec_reg_write_silent(hw, SEC_IPC_HOST_INT_STATUS_REG,
343 		SEC_IPC_HOST_INT_STATUS_PENDING);
344 	mei_txe_br_reg_write(hw, HISR_REG, HISR_INT_STS_MSK);
345 	mei_txe_br_reg_write(hw, HHISR_REG, IPC_HHIER_MSK);
346 }
347 
348 /**
349  * mei_txe_intr_disable - disable all interrupts
350  *
351  * @dev: the device structure
352  */
353 static void mei_txe_intr_disable(struct mei_device *dev)
354 {
355 	struct mei_txe_hw *hw = to_txe_hw(dev);
356 	mei_txe_br_reg_write(hw, HHIER_REG, 0);
357 	mei_txe_br_reg_write(hw, HIER_REG, 0);
358 }
359 /**
360  * mei_txe_intr_disable - enable all interrupts
361  *
362  * @dev: the device structure
363  */
364 static void mei_txe_intr_enable(struct mei_device *dev)
365 {
366 	struct mei_txe_hw *hw = to_txe_hw(dev);
367 	mei_txe_br_reg_write(hw, HHIER_REG, IPC_HHIER_MSK);
368 	mei_txe_br_reg_write(hw, HIER_REG, HIER_INT_EN_MSK);
369 }
370 
371 /**
372  * mei_txe_pending_interrupts - check if there are pending interrupts
373  *	only Aliveness, Input ready, and output doorbell are of relevance
374  *
375  * @dev: the device structure
376  *
377  * Checks if there are pending interrupts
378  * only Aliveness, Readiness, Input ready, and Output doorbell are relevant
379  */
380 static bool mei_txe_pending_interrupts(struct mei_device *dev)
381 {
382 
383 	struct mei_txe_hw *hw = to_txe_hw(dev);
384 	bool ret = (hw->intr_cause & (TXE_INTR_READINESS |
385 				      TXE_INTR_ALIVENESS |
386 				      TXE_INTR_IN_READY  |
387 				      TXE_INTR_OUT_DB));
388 
389 	if (ret) {
390 		dev_dbg(&dev->pdev->dev,
391 			"Pending Interrupts InReady=%01d Readiness=%01d, Aliveness=%01d, OutDoor=%01d\n",
392 			!!(hw->intr_cause & TXE_INTR_IN_READY),
393 			!!(hw->intr_cause & TXE_INTR_READINESS),
394 			!!(hw->intr_cause & TXE_INTR_ALIVENESS),
395 			!!(hw->intr_cause & TXE_INTR_OUT_DB));
396 	}
397 	return ret;
398 }
399 
400 /**
401  * mei_txe_input_payload_write - write a dword to the host buffer
402  *	at offset idx
403  *
404  * @dev: the device structure
405  * @idx: index in the host buffer
406  * @value: value
407  */
408 static void mei_txe_input_payload_write(struct mei_device *dev,
409 			unsigned long idx, u32 value)
410 {
411 	struct mei_txe_hw *hw = to_txe_hw(dev);
412 	mei_txe_sec_reg_write(hw, SEC_IPC_INPUT_PAYLOAD_REG +
413 			(idx * sizeof(u32)), value);
414 }
415 
416 /**
417  * mei_txe_out_data_read - read dword from the device buffer
418  *	at offset idx
419  *
420  * @dev: the device structure
421  * @idx: index in the device buffer
422  *
423  * returns register value at index
424  */
425 static u32 mei_txe_out_data_read(const struct mei_device *dev,
426 					unsigned long idx)
427 {
428 	struct mei_txe_hw *hw = to_txe_hw(dev);
429 	return mei_txe_br_reg_read(hw,
430 		BRIDGE_IPC_OUTPUT_PAYLOAD_REG + (idx * sizeof(u32)));
431 }
432 
433 /* Readiness */
434 
435 /**
436  * mei_txe_readiness_set_host_rdy
437  *
438  * @dev: the device structure
439  */
440 static void mei_txe_readiness_set_host_rdy(struct mei_device *dev)
441 {
442 	struct mei_txe_hw *hw = to_txe_hw(dev);
443 	mei_txe_br_reg_write(hw,
444 		SICR_HOST_IPC_READINESS_REQ_REG,
445 		SICR_HOST_IPC_READINESS_HOST_RDY);
446 }
447 
448 /**
449  * mei_txe_readiness_clear
450  *
451  * @dev: the device structure
452  */
453 static void mei_txe_readiness_clear(struct mei_device *dev)
454 {
455 	struct mei_txe_hw *hw = to_txe_hw(dev);
456 	mei_txe_br_reg_write(hw, SICR_HOST_IPC_READINESS_REQ_REG,
457 				SICR_HOST_IPC_READINESS_RDY_CLR);
458 }
459 /**
460  * mei_txe_readiness_get - Reads and returns
461  *	the HICR_SEC_IPC_READINESS register value
462  *
463  * @dev: the device structure
464  */
465 static u32 mei_txe_readiness_get(struct mei_device *dev)
466 {
467 	struct mei_txe_hw *hw = to_txe_hw(dev);
468 	return mei_txe_br_reg_read(hw, HICR_SEC_IPC_READINESS_REG);
469 }
470 
471 
472 /**
473  * mei_txe_readiness_is_sec_rdy - check readiness
474  *  for HICR_SEC_IPC_READINESS_SEC_RDY
475  *
476  * @readiness - cached readiness state
477  */
478 static inline bool mei_txe_readiness_is_sec_rdy(u32 readiness)
479 {
480 	return !!(readiness & HICR_SEC_IPC_READINESS_SEC_RDY);
481 }
482 
483 /**
484  * mei_txe_hw_is_ready - check if the hw is ready
485  *
486  * @dev: the device structure
487  */
488 static bool mei_txe_hw_is_ready(struct mei_device *dev)
489 {
490 	u32 readiness =  mei_txe_readiness_get(dev);
491 	return mei_txe_readiness_is_sec_rdy(readiness);
492 }
493 
494 /**
495  * mei_txe_host_is_ready - check if the host is ready
496  *
497  * @dev: the device structure
498  */
499 static inline bool mei_txe_host_is_ready(struct mei_device *dev)
500 {
501 	struct mei_txe_hw *hw = to_txe_hw(dev);
502 	u32 reg = mei_txe_br_reg_read(hw, HICR_SEC_IPC_READINESS_REG);
503 	return !!(reg & HICR_SEC_IPC_READINESS_HOST_RDY);
504 }
505 
506 /**
507  * mei_txe_readiness_wait - wait till readiness settles
508  *
509  * @dev: the device structure
510  *
511  * returns 0 on success and -ETIME on timeout
512  */
513 static int mei_txe_readiness_wait(struct mei_device *dev)
514 {
515 	if (mei_txe_hw_is_ready(dev))
516 		return 0;
517 
518 	mutex_unlock(&dev->device_lock);
519 	wait_event_timeout(dev->wait_hw_ready, dev->recvd_hw_ready,
520 			msecs_to_jiffies(SEC_RESET_WAIT_TIMEOUT));
521 	mutex_lock(&dev->device_lock);
522 	if (!dev->recvd_hw_ready) {
523 		dev_err(&dev->pdev->dev, "wait for readiness failed\n");
524 		return -ETIME;
525 	}
526 
527 	dev->recvd_hw_ready = false;
528 	return 0;
529 }
530 
531 /**
532  *  mei_txe_hw_config - configure hardware at the start of the devices
533  *
534  * @dev: the device structure
535  *
536  * Configure hardware at the start of the device should be done only
537  *   once at the device probe time
538  */
539 static void mei_txe_hw_config(struct mei_device *dev)
540 {
541 
542 	struct mei_txe_hw *hw = to_txe_hw(dev);
543 	/* Doesn't change in runtime */
544 	dev->hbuf_depth = PAYLOAD_SIZE / 4;
545 
546 	hw->aliveness = mei_txe_aliveness_get(dev);
547 	hw->readiness = mei_txe_readiness_get(dev);
548 
549 	dev_dbg(&dev->pdev->dev, "aliveness_resp = 0x%08x, readiness = 0x%08x.\n",
550 		hw->aliveness, hw->readiness);
551 }
552 
553 
554 /**
555  * mei_txe_write - writes a message to device.
556  *
557  * @dev: the device structure
558  * @header: header of message
559  * @buf: message buffer will be written
560  * returns 1 if success, 0 - otherwise.
561  */
562 
563 static int mei_txe_write(struct mei_device *dev,
564 		struct mei_msg_hdr *header, unsigned char *buf)
565 {
566 	struct mei_txe_hw *hw = to_txe_hw(dev);
567 	unsigned long rem;
568 	unsigned long length;
569 	int slots = dev->hbuf_depth;
570 	u32 *reg_buf = (u32 *)buf;
571 	u32 dw_cnt;
572 	int i;
573 
574 	if (WARN_ON(!header || !buf))
575 		return -EINVAL;
576 
577 	length = header->length;
578 
579 	dev_dbg(&dev->pdev->dev, MEI_HDR_FMT, MEI_HDR_PRM(header));
580 
581 	dw_cnt = mei_data2slots(length);
582 	if (dw_cnt > slots)
583 		return -EMSGSIZE;
584 
585 	if (WARN(!hw->aliveness, "txe write: aliveness not asserted\n"))
586 		return -EAGAIN;
587 
588 	/* Enable Input Ready Interrupt. */
589 	mei_txe_input_ready_interrupt_enable(dev);
590 
591 	if (!mei_txe_is_input_ready(dev)) {
592 		dev_err(&dev->pdev->dev, "Input is not ready");
593 		return -EAGAIN;
594 	}
595 
596 	mei_txe_input_payload_write(dev, 0, *((u32 *)header));
597 
598 	for (i = 0; i < length / 4; i++)
599 		mei_txe_input_payload_write(dev, i + 1, reg_buf[i]);
600 
601 	rem = length & 0x3;
602 	if (rem > 0) {
603 		u32 reg = 0;
604 		memcpy(&reg, &buf[length - rem], rem);
605 		mei_txe_input_payload_write(dev, i + 1, reg);
606 	}
607 
608 	/* after each write the whole buffer is consumed */
609 	hw->slots = 0;
610 
611 	/* Set Input-Doorbell */
612 	mei_txe_input_doorbell_set(hw);
613 
614 	return 0;
615 }
616 
617 /**
618  * mei_txe_hbuf_max_len - mimics the me hbuf circular buffer
619  *
620  * @dev: the device structure
621  *
622  * returns the PAYLOAD_SIZE - 4
623  */
624 static size_t mei_txe_hbuf_max_len(const struct mei_device *dev)
625 {
626 	return PAYLOAD_SIZE - sizeof(struct mei_msg_hdr);
627 }
628 
629 /**
630  * mei_txe_hbuf_empty_slots - mimics the me hbuf circular buffer
631  *
632  * @dev: the device structure
633  *
634  * returns always hbuf_depth
635  */
636 static int mei_txe_hbuf_empty_slots(struct mei_device *dev)
637 {
638 	struct mei_txe_hw *hw = to_txe_hw(dev);
639 	return hw->slots;
640 }
641 
642 /**
643  * mei_txe_count_full_read_slots - mimics the me device circular buffer
644  *
645  * @dev: the device structure
646  *
647  * returns always buffer size in dwords count
648  */
649 static int mei_txe_count_full_read_slots(struct mei_device *dev)
650 {
651 	/* read buffers has static size */
652 	return  PAYLOAD_SIZE / 4;
653 }
654 
655 /**
656  * mei_txe_read_hdr - read message header which is always in 4 first bytes
657  *
658  * @dev: the device structure
659  *
660  * returns mei message header
661  */
662 
663 static u32 mei_txe_read_hdr(const struct mei_device *dev)
664 {
665 	return mei_txe_out_data_read(dev, 0);
666 }
667 /**
668  * mei_txe_read - reads a message from the txe device.
669  *
670  * @dev: the device structure
671  * @buf: message buffer will be written
672  * @len: message size will be read
673  *
674  * returns -EINVAL on error wrong argument and 0 on success
675  */
676 static int mei_txe_read(struct mei_device *dev,
677 		unsigned char *buf, unsigned long len)
678 {
679 
680 	struct mei_txe_hw *hw = to_txe_hw(dev);
681 	u32 i;
682 	u32 *reg_buf = (u32 *)buf;
683 	u32 rem = len & 0x3;
684 
685 	if (WARN_ON(!buf || !len))
686 		return -EINVAL;
687 
688 	dev_dbg(&dev->pdev->dev,
689 		"buffer-length = %lu buf[0]0x%08X\n",
690 		len, mei_txe_out_data_read(dev, 0));
691 
692 	for (i = 0; i < len / 4; i++) {
693 		/* skip header: index starts from 1 */
694 		u32 reg = mei_txe_out_data_read(dev, i + 1);
695 		dev_dbg(&dev->pdev->dev, "buf[%d] = 0x%08X\n", i, reg);
696 		*reg_buf++ = reg;
697 	}
698 
699 	if (rem) {
700 		u32 reg = mei_txe_out_data_read(dev, i + 1);
701 		memcpy(reg_buf, &reg, rem);
702 	}
703 
704 	mei_txe_output_ready_set(hw);
705 	return 0;
706 }
707 
708 /**
709  * mei_txe_hw_reset - resets host and fw.
710  *
711  * @dev: the device structure
712  * @intr_enable: if interrupt should be enabled after reset.
713  *
714  * returns 0 on success and < 0 in case of error
715  */
716 static int mei_txe_hw_reset(struct mei_device *dev, bool intr_enable)
717 {
718 	struct mei_txe_hw *hw = to_txe_hw(dev);
719 
720 	u32 aliveness_req;
721 	/*
722 	 * read input doorbell to ensure consistency between  Bridge and SeC
723 	 * return value might be garbage return
724 	 */
725 	(void)mei_txe_sec_reg_read_silent(hw, SEC_IPC_INPUT_DOORBELL_REG);
726 
727 	aliveness_req = mei_txe_aliveness_req_get(dev);
728 	hw->aliveness = mei_txe_aliveness_get(dev);
729 
730 	/* Disable interrupts in this stage we will poll */
731 	mei_txe_intr_disable(dev);
732 
733 	/*
734 	 * If Aliveness Request and Aliveness Response are not equal then
735 	 * wait for them to be equal
736 	 * Since we might have interrupts disabled - poll for it
737 	 */
738 	if (aliveness_req != hw->aliveness)
739 		if (mei_txe_aliveness_poll(dev, aliveness_req) < 0) {
740 			dev_err(&dev->pdev->dev,
741 				"wait for aliveness settle failed ... bailing out\n");
742 			return -EIO;
743 		}
744 
745 	/*
746 	 * If Aliveness Request and Aliveness Response are set then clear them
747 	 */
748 	if (aliveness_req) {
749 		mei_txe_aliveness_set(dev, 0);
750 		if (mei_txe_aliveness_poll(dev, 0) < 0) {
751 			dev_err(&dev->pdev->dev,
752 				"wait for aliveness failed ... bailing out\n");
753 			return -EIO;
754 		}
755 	}
756 
757 	/*
758 	 * Set rediness RDY_CLR bit
759 	 */
760 	mei_txe_readiness_clear(dev);
761 
762 	return 0;
763 }
764 
765 /**
766  * mei_txe_hw_start - start the hardware after reset
767  *
768  * @dev: the device structure
769  *
770  * returns 0 on success and < 0 in case of error
771  */
772 static int mei_txe_hw_start(struct mei_device *dev)
773 {
774 	struct mei_txe_hw *hw = to_txe_hw(dev);
775 	int ret;
776 
777 	u32 hisr;
778 
779 	/* bring back interrupts */
780 	mei_txe_intr_enable(dev);
781 
782 	ret = mei_txe_readiness_wait(dev);
783 	if (ret < 0) {
784 		dev_err(&dev->pdev->dev, "wating for readiness failed\n");
785 		return ret;
786 	}
787 
788 	/*
789 	 * If HISR.INT2_STS interrupt status bit is set then clear it.
790 	 */
791 	hisr = mei_txe_br_reg_read(hw, HISR_REG);
792 	if (hisr & HISR_INT_2_STS)
793 		mei_txe_br_reg_write(hw, HISR_REG, HISR_INT_2_STS);
794 
795 	/* Clear the interrupt cause of OutputDoorbell */
796 	clear_bit(TXE_INTR_OUT_DB_BIT, &hw->intr_cause);
797 
798 	ret = mei_txe_aliveness_set_sync(dev, 1);
799 	if (ret < 0) {
800 		dev_err(&dev->pdev->dev, "wait for aliveness failed ... bailing out\n");
801 		return ret;
802 	}
803 
804 	/* enable input ready interrupts:
805 	 * SEC_IPC_HOST_INT_MASK.IPC_INPUT_READY_INT_MASK
806 	 */
807 	mei_txe_input_ready_interrupt_enable(dev);
808 
809 
810 	/*  Set the SICR_SEC_IPC_OUTPUT_STATUS.IPC_OUTPUT_READY bit */
811 	mei_txe_output_ready_set(hw);
812 
813 	/* Set bit SICR_HOST_IPC_READINESS.HOST_RDY
814 	 */
815 	mei_txe_readiness_set_host_rdy(dev);
816 
817 	return 0;
818 }
819 
820 /**
821  * mei_txe_check_and_ack_intrs - translate multi BAR interrupt into
822  *  single bit mask and acknowledge the interrupts
823  *
824  * @dev: the device structure
825  * @do_ack: acknowledge interrupts
826  */
827 static bool mei_txe_check_and_ack_intrs(struct mei_device *dev, bool do_ack)
828 {
829 	struct mei_txe_hw *hw = to_txe_hw(dev);
830 	u32 hisr;
831 	u32 hhisr;
832 	u32 ipc_isr;
833 	u32 aliveness;
834 	bool generated;
835 
836 	/* read interrupt registers */
837 	hhisr = mei_txe_br_reg_read(hw, HHISR_REG);
838 	generated = (hhisr & IPC_HHIER_MSK);
839 	if (!generated)
840 		goto out;
841 
842 	hisr = mei_txe_br_reg_read(hw, HISR_REG);
843 
844 	aliveness = mei_txe_aliveness_get(dev);
845 	if (hhisr & IPC_HHIER_SEC && aliveness)
846 		ipc_isr = mei_txe_sec_reg_read_silent(hw,
847 				SEC_IPC_HOST_INT_STATUS_REG);
848 	else
849 		ipc_isr = 0;
850 
851 	generated = generated ||
852 		(hisr & HISR_INT_STS_MSK) ||
853 		(ipc_isr & SEC_IPC_HOST_INT_STATUS_PENDING);
854 
855 	if (generated && do_ack) {
856 		/* Save the interrupt causes */
857 		hw->intr_cause |= hisr & HISR_INT_STS_MSK;
858 		if (ipc_isr & SEC_IPC_HOST_INT_STATUS_IN_RDY)
859 			hw->intr_cause |= TXE_INTR_IN_READY;
860 
861 
862 		mei_txe_intr_disable(dev);
863 		/* Clear the interrupts in hierarchy:
864 		 * IPC and Bridge, than the High Level */
865 		mei_txe_sec_reg_write_silent(hw,
866 			SEC_IPC_HOST_INT_STATUS_REG, ipc_isr);
867 		mei_txe_br_reg_write(hw, HISR_REG, hisr);
868 		mei_txe_br_reg_write(hw, HHISR_REG, hhisr);
869 	}
870 
871 out:
872 	return generated;
873 }
874 
875 /**
876  * mei_txe_irq_quick_handler - The ISR of the MEI device
877  *
878  * @irq: The irq number
879  * @dev_id: pointer to the device structure
880  *
881  * returns irqreturn_t
882  */
883 irqreturn_t mei_txe_irq_quick_handler(int irq, void *dev_id)
884 {
885 	struct mei_device *dev = dev_id;
886 
887 	if (mei_txe_check_and_ack_intrs(dev, true))
888 		return IRQ_WAKE_THREAD;
889 	return IRQ_NONE;
890 }
891 
892 
893 /**
894  * mei_txe_irq_thread_handler - txe interrupt thread
895  *
896  * @irq: The irq number
897  * @dev_id: pointer to the device structure
898  *
899  * returns irqreturn_t
900  *
901  */
902 irqreturn_t mei_txe_irq_thread_handler(int irq, void *dev_id)
903 {
904 	struct mei_device *dev = (struct mei_device *) dev_id;
905 	struct mei_txe_hw *hw = to_txe_hw(dev);
906 	struct mei_cl_cb complete_list;
907 	s32 slots;
908 	int rets = 0;
909 
910 	dev_dbg(&dev->pdev->dev, "irq thread: Interrupt Registers HHISR|HISR|SEC=%02X|%04X|%02X\n",
911 		mei_txe_br_reg_read(hw, HHISR_REG),
912 		mei_txe_br_reg_read(hw, HISR_REG),
913 		mei_txe_sec_reg_read_silent(hw, SEC_IPC_HOST_INT_STATUS_REG));
914 
915 
916 	/* initialize our complete list */
917 	mutex_lock(&dev->device_lock);
918 	mei_io_list_init(&complete_list);
919 
920 	if (pci_dev_msi_enabled(dev->pdev))
921 		mei_txe_check_and_ack_intrs(dev, true);
922 
923 	/* show irq events */
924 	mei_txe_pending_interrupts(dev);
925 
926 	hw->aliveness = mei_txe_aliveness_get(dev);
927 	hw->readiness = mei_txe_readiness_get(dev);
928 
929 	/* Readiness:
930 	 * Detection of TXE driver going through reset
931 	 * or TXE driver resetting the HECI interface.
932 	 */
933 	if (test_and_clear_bit(TXE_INTR_READINESS_BIT, &hw->intr_cause)) {
934 		dev_dbg(&dev->pdev->dev, "Readiness Interrupt was received...\n");
935 
936 		/* Check if SeC is going through reset */
937 		if (mei_txe_readiness_is_sec_rdy(hw->readiness)) {
938 			dev_dbg(&dev->pdev->dev, "we need to start the dev.\n");
939 			dev->recvd_hw_ready = true;
940 		} else {
941 			dev->recvd_hw_ready = false;
942 			if (dev->dev_state != MEI_DEV_RESETTING) {
943 
944 				dev_warn(&dev->pdev->dev, "FW not ready: resetting.\n");
945 				schedule_work(&dev->reset_work);
946 				goto end;
947 
948 			}
949 		}
950 		wake_up(&dev->wait_hw_ready);
951 	}
952 
953 	/************************************************************/
954 	/* Check interrupt cause:
955 	 * Aliveness: Detection of SeC acknowledge of host request that
956 	 * it remain alive or host cancellation of that request.
957 	 */
958 
959 	if (test_and_clear_bit(TXE_INTR_ALIVENESS_BIT, &hw->intr_cause)) {
960 		/* Clear the interrupt cause */
961 		dev_dbg(&dev->pdev->dev,
962 			"Aliveness Interrupt: Status: %d\n", hw->aliveness);
963 		hw->recvd_aliveness = true;
964 		if (waitqueue_active(&hw->wait_aliveness))
965 			wake_up(&hw->wait_aliveness);
966 	}
967 
968 
969 	/* Output Doorbell:
970 	 * Detection of SeC having sent output to host
971 	 */
972 	slots = mei_count_full_read_slots(dev);
973 	if (test_and_clear_bit(TXE_INTR_OUT_DB_BIT, &hw->intr_cause)) {
974 		/* Read from TXE */
975 		rets = mei_irq_read_handler(dev, &complete_list, &slots);
976 		if (rets && dev->dev_state != MEI_DEV_RESETTING) {
977 			dev_err(&dev->pdev->dev,
978 				"mei_irq_read_handler ret = %d.\n", rets);
979 
980 			schedule_work(&dev->reset_work);
981 			goto end;
982 		}
983 	}
984 	/* Input Ready: Detection if host can write to SeC */
985 	if (test_and_clear_bit(TXE_INTR_IN_READY_BIT, &hw->intr_cause)) {
986 		dev->hbuf_is_ready = true;
987 		hw->slots = dev->hbuf_depth;
988 	}
989 
990 	if (hw->aliveness && dev->hbuf_is_ready) {
991 		/* get the real register value */
992 		dev->hbuf_is_ready = mei_hbuf_is_ready(dev);
993 		rets = mei_irq_write_handler(dev, &complete_list);
994 		if (rets && rets != -EMSGSIZE)
995 			dev_err(&dev->pdev->dev, "mei_irq_write_handler ret = %d.\n",
996 				rets);
997 		dev->hbuf_is_ready = mei_hbuf_is_ready(dev);
998 	}
999 
1000 	mei_irq_compl_handler(dev, &complete_list);
1001 
1002 end:
1003 	dev_dbg(&dev->pdev->dev, "interrupt thread end ret = %d\n", rets);
1004 
1005 	mutex_unlock(&dev->device_lock);
1006 
1007 	mei_enable_interrupts(dev);
1008 	return IRQ_HANDLED;
1009 }
1010 
1011 static const struct mei_hw_ops mei_txe_hw_ops = {
1012 
1013 	.host_is_ready = mei_txe_host_is_ready,
1014 
1015 	.hw_is_ready = mei_txe_hw_is_ready,
1016 	.hw_reset = mei_txe_hw_reset,
1017 	.hw_config = mei_txe_hw_config,
1018 	.hw_start = mei_txe_hw_start,
1019 
1020 	.intr_clear = mei_txe_intr_clear,
1021 	.intr_enable = mei_txe_intr_enable,
1022 	.intr_disable = mei_txe_intr_disable,
1023 
1024 	.hbuf_free_slots = mei_txe_hbuf_empty_slots,
1025 	.hbuf_is_ready = mei_txe_is_input_ready,
1026 	.hbuf_max_len = mei_txe_hbuf_max_len,
1027 
1028 	.write = mei_txe_write,
1029 
1030 	.rdbuf_full_slots = mei_txe_count_full_read_slots,
1031 	.read_hdr = mei_txe_read_hdr,
1032 
1033 	.read = mei_txe_read,
1034 
1035 };
1036 
1037 /**
1038  * mei_txe_dev_init - allocates and initializes txe hardware specific structure
1039  *
1040  * @pdev - pci device
1041  * returns struct mei_device * on success or NULL;
1042  *
1043  */
1044 struct mei_device *mei_txe_dev_init(struct pci_dev *pdev)
1045 {
1046 	struct mei_device *dev;
1047 	struct mei_txe_hw *hw;
1048 
1049 	dev = kzalloc(sizeof(struct mei_device) +
1050 			 sizeof(struct mei_txe_hw), GFP_KERNEL);
1051 	if (!dev)
1052 		return NULL;
1053 
1054 	mei_device_init(dev);
1055 
1056 	hw = to_txe_hw(dev);
1057 
1058 	init_waitqueue_head(&hw->wait_aliveness);
1059 
1060 	dev->ops = &mei_txe_hw_ops;
1061 
1062 	dev->pdev = pdev;
1063 	return dev;
1064 }
1065 
1066 /**
1067  * mei_txe_setup_satt2 - SATT2 configuration for DMA support.
1068  *
1069  * @dev:   the device structure
1070  * @addr:  physical address start of the range
1071  * @range: physical range size
1072  */
1073 int mei_txe_setup_satt2(struct mei_device *dev, phys_addr_t addr, u32 range)
1074 {
1075 	struct mei_txe_hw *hw = to_txe_hw(dev);
1076 
1077 	u32 lo32 = lower_32_bits(addr);
1078 	u32 hi32 = upper_32_bits(addr);
1079 	u32 ctrl;
1080 
1081 	/* SATT is limited to 36 Bits */
1082 	if (hi32 & ~0xF)
1083 		return -EINVAL;
1084 
1085 	/* SATT has to be 16Byte aligned */
1086 	if (lo32 & 0xF)
1087 		return -EINVAL;
1088 
1089 	/* SATT range has to be 4Bytes aligned */
1090 	if (range & 0x4)
1091 		return -EINVAL;
1092 
1093 	/* SATT is limited to 32 MB range*/
1094 	if (range > SATT_RANGE_MAX)
1095 		return -EINVAL;
1096 
1097 	ctrl = SATT2_CTRL_VALID_MSK;
1098 	ctrl |= hi32  << SATT2_CTRL_BR_BASE_ADDR_REG_SHIFT;
1099 
1100 	mei_txe_br_reg_write(hw, SATT2_SAP_SIZE_REG, range);
1101 	mei_txe_br_reg_write(hw, SATT2_BRG_BA_LSB_REG, lo32);
1102 	mei_txe_br_reg_write(hw, SATT2_CTRL_REG, ctrl);
1103 	dev_dbg(&dev->pdev->dev, "SATT2: SAP_SIZE_OFFSET=0x%08X, BRG_BA_LSB_OFFSET=0x%08X, CTRL_OFFSET=0x%08X\n",
1104 		range, lo32, ctrl);
1105 
1106 	return 0;
1107 }
1108