xref: /openbmc/linux/drivers/misc/mei/hw-txe.c (revision 20e2fc42)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2013-2014, Intel Corporation. All rights reserved.
4  * Intel Management Engine Interface (Intel MEI) Linux driver
5  */
6 
7 #include <linux/pci.h>
8 #include <linux/jiffies.h>
9 #include <linux/ktime.h>
10 #include <linux/delay.h>
11 #include <linux/kthread.h>
12 #include <linux/interrupt.h>
13 #include <linux/pm_runtime.h>
14 
15 #include <linux/mei.h>
16 
17 #include "mei_dev.h"
18 #include "hw-txe.h"
19 #include "client.h"
20 #include "hbm.h"
21 
22 #include "mei-trace.h"
23 
24 #define TXE_HBUF_DEPTH (PAYLOAD_SIZE / MEI_SLOT_SIZE)
25 
26 /**
27  * mei_txe_reg_read - Reads 32bit data from the txe device
28  *
29  * @base_addr: registers base address
30  * @offset: register offset
31  *
32  * Return: register value
33  */
34 static inline u32 mei_txe_reg_read(void __iomem *base_addr,
35 					unsigned long offset)
36 {
37 	return ioread32(base_addr + offset);
38 }
39 
40 /**
41  * mei_txe_reg_write - Writes 32bit data to the txe device
42  *
43  * @base_addr: registers base address
44  * @offset: register offset
45  * @value: the value to write
46  */
47 static inline void mei_txe_reg_write(void __iomem *base_addr,
48 				unsigned long offset, u32 value)
49 {
50 	iowrite32(value, base_addr + offset);
51 }
52 
53 /**
54  * mei_txe_sec_reg_read_silent - Reads 32bit data from the SeC BAR
55  *
56  * @hw: the txe hardware structure
57  * @offset: register offset
58  *
59  * Doesn't check for aliveness while Reads 32bit data from the SeC BAR
60  *
61  * Return: register value
62  */
63 static inline u32 mei_txe_sec_reg_read_silent(struct mei_txe_hw *hw,
64 				unsigned long offset)
65 {
66 	return mei_txe_reg_read(hw->mem_addr[SEC_BAR], offset);
67 }
68 
69 /**
70  * mei_txe_sec_reg_read - Reads 32bit data from the SeC BAR
71  *
72  * @hw: the txe hardware structure
73  * @offset: register offset
74  *
75  * Reads 32bit data from the SeC BAR and shout loud if aliveness is not set
76  *
77  * Return: register value
78  */
79 static inline u32 mei_txe_sec_reg_read(struct mei_txe_hw *hw,
80 				unsigned long offset)
81 {
82 	WARN(!hw->aliveness, "sec read: aliveness not asserted\n");
83 	return mei_txe_sec_reg_read_silent(hw, offset);
84 }
85 /**
86  * mei_txe_sec_reg_write_silent - Writes 32bit data to the SeC BAR
87  *   doesn't check for aliveness
88  *
89  * @hw: the txe hardware structure
90  * @offset: register offset
91  * @value: value to write
92  *
93  * Doesn't check for aliveness while writes 32bit data from to the SeC BAR
94  */
95 static inline void mei_txe_sec_reg_write_silent(struct mei_txe_hw *hw,
96 				unsigned long offset, u32 value)
97 {
98 	mei_txe_reg_write(hw->mem_addr[SEC_BAR], offset, value);
99 }
100 
101 /**
102  * mei_txe_sec_reg_write - Writes 32bit data to the SeC BAR
103  *
104  * @hw: the txe hardware structure
105  * @offset: register offset
106  * @value: value to write
107  *
108  * Writes 32bit data from the SeC BAR and shout loud if aliveness is not set
109  */
110 static inline void mei_txe_sec_reg_write(struct mei_txe_hw *hw,
111 				unsigned long offset, u32 value)
112 {
113 	WARN(!hw->aliveness, "sec write: aliveness not asserted\n");
114 	mei_txe_sec_reg_write_silent(hw, offset, value);
115 }
116 /**
117  * mei_txe_br_reg_read - Reads 32bit data from the Bridge BAR
118  *
119  * @hw: the txe hardware structure
120  * @offset: offset from which to read the data
121  *
122  * Return: the byte read.
123  */
124 static inline u32 mei_txe_br_reg_read(struct mei_txe_hw *hw,
125 				unsigned long offset)
126 {
127 	return mei_txe_reg_read(hw->mem_addr[BRIDGE_BAR], offset);
128 }
129 
130 /**
131  * mei_txe_br_reg_write - Writes 32bit data to the Bridge BAR
132  *
133  * @hw: the txe hardware structure
134  * @offset: offset from which to write the data
135  * @value: the byte to write
136  */
137 static inline void mei_txe_br_reg_write(struct mei_txe_hw *hw,
138 				unsigned long offset, u32 value)
139 {
140 	mei_txe_reg_write(hw->mem_addr[BRIDGE_BAR], offset, value);
141 }
142 
143 /**
144  * mei_txe_aliveness_set - request for aliveness change
145  *
146  * @dev: the device structure
147  * @req: requested aliveness value
148  *
149  * Request for aliveness change and returns true if the change is
150  *   really needed and false if aliveness is already
151  *   in the requested state
152  *
153  * Locking: called under "dev->device_lock" lock
154  *
155  * Return: true if request was send
156  */
157 static bool mei_txe_aliveness_set(struct mei_device *dev, u32 req)
158 {
159 
160 	struct mei_txe_hw *hw = to_txe_hw(dev);
161 	bool do_req = hw->aliveness != req;
162 
163 	dev_dbg(dev->dev, "Aliveness current=%d request=%d\n",
164 				hw->aliveness, req);
165 	if (do_req) {
166 		dev->pg_event = MEI_PG_EVENT_WAIT;
167 		mei_txe_br_reg_write(hw, SICR_HOST_ALIVENESS_REQ_REG, req);
168 	}
169 	return do_req;
170 }
171 
172 
173 /**
174  * mei_txe_aliveness_req_get - get aliveness requested register value
175  *
176  * @dev: the device structure
177  *
178  * Extract HICR_HOST_ALIVENESS_RESP_ACK bit from
179  * from HICR_HOST_ALIVENESS_REQ register value
180  *
181  * Return: SICR_HOST_ALIVENESS_REQ_REQUESTED bit value
182  */
183 static u32 mei_txe_aliveness_req_get(struct mei_device *dev)
184 {
185 	struct mei_txe_hw *hw = to_txe_hw(dev);
186 	u32 reg;
187 
188 	reg = mei_txe_br_reg_read(hw, SICR_HOST_ALIVENESS_REQ_REG);
189 	return reg & SICR_HOST_ALIVENESS_REQ_REQUESTED;
190 }
191 
192 /**
193  * mei_txe_aliveness_get - get aliveness response register value
194  *
195  * @dev: the device structure
196  *
197  * Return: HICR_HOST_ALIVENESS_RESP_ACK bit from HICR_HOST_ALIVENESS_RESP
198  *         register
199  */
200 static u32 mei_txe_aliveness_get(struct mei_device *dev)
201 {
202 	struct mei_txe_hw *hw = to_txe_hw(dev);
203 	u32 reg;
204 
205 	reg = mei_txe_br_reg_read(hw, HICR_HOST_ALIVENESS_RESP_REG);
206 	return reg & HICR_HOST_ALIVENESS_RESP_ACK;
207 }
208 
209 /**
210  * mei_txe_aliveness_poll - waits for aliveness to settle
211  *
212  * @dev: the device structure
213  * @expected: expected aliveness value
214  *
215  * Polls for HICR_HOST_ALIVENESS_RESP.ALIVENESS_RESP to be set
216  *
217  * Return: 0 if the expected value was received, -ETIME otherwise
218  */
219 static int mei_txe_aliveness_poll(struct mei_device *dev, u32 expected)
220 {
221 	struct mei_txe_hw *hw = to_txe_hw(dev);
222 	ktime_t stop, start;
223 
224 	start = ktime_get();
225 	stop = ktime_add(start, ms_to_ktime(SEC_ALIVENESS_WAIT_TIMEOUT));
226 	do {
227 		hw->aliveness = mei_txe_aliveness_get(dev);
228 		if (hw->aliveness == expected) {
229 			dev->pg_event = MEI_PG_EVENT_IDLE;
230 			dev_dbg(dev->dev, "aliveness settled after %lld usecs\n",
231 				ktime_to_us(ktime_sub(ktime_get(), start)));
232 			return 0;
233 		}
234 		usleep_range(20, 50);
235 	} while (ktime_before(ktime_get(), stop));
236 
237 	dev->pg_event = MEI_PG_EVENT_IDLE;
238 	dev_err(dev->dev, "aliveness timed out\n");
239 	return -ETIME;
240 }
241 
242 /**
243  * mei_txe_aliveness_wait - waits for aliveness to settle
244  *
245  * @dev: the device structure
246  * @expected: expected aliveness value
247  *
248  * Waits for HICR_HOST_ALIVENESS_RESP.ALIVENESS_RESP to be set
249  *
250  * Return: 0 on success and < 0 otherwise
251  */
252 static int mei_txe_aliveness_wait(struct mei_device *dev, u32 expected)
253 {
254 	struct mei_txe_hw *hw = to_txe_hw(dev);
255 	const unsigned long timeout =
256 			msecs_to_jiffies(SEC_ALIVENESS_WAIT_TIMEOUT);
257 	long err;
258 	int ret;
259 
260 	hw->aliveness = mei_txe_aliveness_get(dev);
261 	if (hw->aliveness == expected)
262 		return 0;
263 
264 	mutex_unlock(&dev->device_lock);
265 	err = wait_event_timeout(hw->wait_aliveness_resp,
266 			dev->pg_event == MEI_PG_EVENT_RECEIVED, timeout);
267 	mutex_lock(&dev->device_lock);
268 
269 	hw->aliveness = mei_txe_aliveness_get(dev);
270 	ret = hw->aliveness == expected ? 0 : -ETIME;
271 
272 	if (ret)
273 		dev_warn(dev->dev, "aliveness timed out = %ld aliveness = %d event = %d\n",
274 			err, hw->aliveness, dev->pg_event);
275 	else
276 		dev_dbg(dev->dev, "aliveness settled after = %d msec aliveness = %d event = %d\n",
277 			jiffies_to_msecs(timeout - err),
278 			hw->aliveness, dev->pg_event);
279 
280 	dev->pg_event = MEI_PG_EVENT_IDLE;
281 	return ret;
282 }
283 
284 /**
285  * mei_txe_aliveness_set_sync - sets an wait for aliveness to complete
286  *
287  * @dev: the device structure
288  * @req: requested aliveness value
289  *
290  * Return: 0 on success and < 0 otherwise
291  */
292 int mei_txe_aliveness_set_sync(struct mei_device *dev, u32 req)
293 {
294 	if (mei_txe_aliveness_set(dev, req))
295 		return mei_txe_aliveness_wait(dev, req);
296 	return 0;
297 }
298 
299 /**
300  * mei_txe_pg_in_transition - is device now in pg transition
301  *
302  * @dev: the device structure
303  *
304  * Return: true if in pg transition, false otherwise
305  */
306 static bool mei_txe_pg_in_transition(struct mei_device *dev)
307 {
308 	return dev->pg_event == MEI_PG_EVENT_WAIT;
309 }
310 
311 /**
312  * mei_txe_pg_is_enabled - detect if PG is supported by HW
313  *
314  * @dev: the device structure
315  *
316  * Return: true is pg supported, false otherwise
317  */
318 static bool mei_txe_pg_is_enabled(struct mei_device *dev)
319 {
320 	return true;
321 }
322 
323 /**
324  * mei_txe_pg_state  - translate aliveness register value
325  *   to the mei power gating state
326  *
327  * @dev: the device structure
328  *
329  * Return: MEI_PG_OFF if aliveness is on and MEI_PG_ON otherwise
330  */
331 static inline enum mei_pg_state mei_txe_pg_state(struct mei_device *dev)
332 {
333 	struct mei_txe_hw *hw = to_txe_hw(dev);
334 
335 	return hw->aliveness ? MEI_PG_OFF : MEI_PG_ON;
336 }
337 
338 /**
339  * mei_txe_input_ready_interrupt_enable - sets the Input Ready Interrupt
340  *
341  * @dev: the device structure
342  */
343 static void mei_txe_input_ready_interrupt_enable(struct mei_device *dev)
344 {
345 	struct mei_txe_hw *hw = to_txe_hw(dev);
346 	u32 hintmsk;
347 	/* Enable the SEC_IPC_HOST_INT_MASK_IN_RDY interrupt */
348 	hintmsk = mei_txe_sec_reg_read(hw, SEC_IPC_HOST_INT_MASK_REG);
349 	hintmsk |= SEC_IPC_HOST_INT_MASK_IN_RDY;
350 	mei_txe_sec_reg_write(hw, SEC_IPC_HOST_INT_MASK_REG, hintmsk);
351 }
352 
353 /**
354  * mei_txe_input_doorbell_set - sets bit 0 in
355  *    SEC_IPC_INPUT_DOORBELL.IPC_INPUT_DOORBELL.
356  *
357  * @hw: the txe hardware structure
358  */
359 static void mei_txe_input_doorbell_set(struct mei_txe_hw *hw)
360 {
361 	/* Clear the interrupt cause */
362 	clear_bit(TXE_INTR_IN_READY_BIT, &hw->intr_cause);
363 	mei_txe_sec_reg_write(hw, SEC_IPC_INPUT_DOORBELL_REG, 1);
364 }
365 
366 /**
367  * mei_txe_output_ready_set - Sets the SICR_SEC_IPC_OUTPUT_STATUS bit to 1
368  *
369  * @hw: the txe hardware structure
370  */
371 static void mei_txe_output_ready_set(struct mei_txe_hw *hw)
372 {
373 	mei_txe_br_reg_write(hw,
374 			SICR_SEC_IPC_OUTPUT_STATUS_REG,
375 			SEC_IPC_OUTPUT_STATUS_RDY);
376 }
377 
378 /**
379  * mei_txe_is_input_ready - check if TXE is ready for receiving data
380  *
381  * @dev: the device structure
382  *
383  * Return: true if INPUT STATUS READY bit is set
384  */
385 static bool mei_txe_is_input_ready(struct mei_device *dev)
386 {
387 	struct mei_txe_hw *hw = to_txe_hw(dev);
388 	u32 status;
389 
390 	status = mei_txe_sec_reg_read(hw, SEC_IPC_INPUT_STATUS_REG);
391 	return !!(SEC_IPC_INPUT_STATUS_RDY & status);
392 }
393 
394 /**
395  * mei_txe_intr_clear - clear all interrupts
396  *
397  * @dev: the device structure
398  */
399 static inline void mei_txe_intr_clear(struct mei_device *dev)
400 {
401 	struct mei_txe_hw *hw = to_txe_hw(dev);
402 
403 	mei_txe_sec_reg_write_silent(hw, SEC_IPC_HOST_INT_STATUS_REG,
404 		SEC_IPC_HOST_INT_STATUS_PENDING);
405 	mei_txe_br_reg_write(hw, HISR_REG, HISR_INT_STS_MSK);
406 	mei_txe_br_reg_write(hw, HHISR_REG, IPC_HHIER_MSK);
407 }
408 
409 /**
410  * mei_txe_intr_disable - disable all interrupts
411  *
412  * @dev: the device structure
413  */
414 static void mei_txe_intr_disable(struct mei_device *dev)
415 {
416 	struct mei_txe_hw *hw = to_txe_hw(dev);
417 
418 	mei_txe_br_reg_write(hw, HHIER_REG, 0);
419 	mei_txe_br_reg_write(hw, HIER_REG, 0);
420 }
421 /**
422  * mei_txe_intr_enable - enable all interrupts
423  *
424  * @dev: the device structure
425  */
426 static void mei_txe_intr_enable(struct mei_device *dev)
427 {
428 	struct mei_txe_hw *hw = to_txe_hw(dev);
429 
430 	mei_txe_br_reg_write(hw, HHIER_REG, IPC_HHIER_MSK);
431 	mei_txe_br_reg_write(hw, HIER_REG, HIER_INT_EN_MSK);
432 }
433 
434 /**
435  * mei_txe_synchronize_irq - wait for pending IRQ handlers
436  *
437  * @dev: the device structure
438  */
439 static void mei_txe_synchronize_irq(struct mei_device *dev)
440 {
441 	struct pci_dev *pdev = to_pci_dev(dev->dev);
442 
443 	synchronize_irq(pdev->irq);
444 }
445 
446 /**
447  * mei_txe_pending_interrupts - check if there are pending interrupts
448  *	only Aliveness, Input ready, and output doorbell are of relevance
449  *
450  * @dev: the device structure
451  *
452  * Checks if there are pending interrupts
453  * only Aliveness, Readiness, Input ready, and Output doorbell are relevant
454  *
455  * Return: true if there are pending interrupts
456  */
457 static bool mei_txe_pending_interrupts(struct mei_device *dev)
458 {
459 
460 	struct mei_txe_hw *hw = to_txe_hw(dev);
461 	bool ret = (hw->intr_cause & (TXE_INTR_READINESS |
462 				      TXE_INTR_ALIVENESS |
463 				      TXE_INTR_IN_READY  |
464 				      TXE_INTR_OUT_DB));
465 
466 	if (ret) {
467 		dev_dbg(dev->dev,
468 			"Pending Interrupts InReady=%01d Readiness=%01d, Aliveness=%01d, OutDoor=%01d\n",
469 			!!(hw->intr_cause & TXE_INTR_IN_READY),
470 			!!(hw->intr_cause & TXE_INTR_READINESS),
471 			!!(hw->intr_cause & TXE_INTR_ALIVENESS),
472 			!!(hw->intr_cause & TXE_INTR_OUT_DB));
473 	}
474 	return ret;
475 }
476 
477 /**
478  * mei_txe_input_payload_write - write a dword to the host buffer
479  *	at offset idx
480  *
481  * @dev: the device structure
482  * @idx: index in the host buffer
483  * @value: value
484  */
485 static void mei_txe_input_payload_write(struct mei_device *dev,
486 			unsigned long idx, u32 value)
487 {
488 	struct mei_txe_hw *hw = to_txe_hw(dev);
489 
490 	mei_txe_sec_reg_write(hw, SEC_IPC_INPUT_PAYLOAD_REG +
491 			(idx * sizeof(u32)), value);
492 }
493 
494 /**
495  * mei_txe_out_data_read - read dword from the device buffer
496  *	at offset idx
497  *
498  * @dev: the device structure
499  * @idx: index in the device buffer
500  *
501  * Return: register value at index
502  */
503 static u32 mei_txe_out_data_read(const struct mei_device *dev,
504 					unsigned long idx)
505 {
506 	struct mei_txe_hw *hw = to_txe_hw(dev);
507 
508 	return mei_txe_br_reg_read(hw,
509 		BRIDGE_IPC_OUTPUT_PAYLOAD_REG + (idx * sizeof(u32)));
510 }
511 
512 /* Readiness */
513 
514 /**
515  * mei_txe_readiness_set_host_rdy - set host readiness bit
516  *
517  * @dev: the device structure
518  */
519 static void mei_txe_readiness_set_host_rdy(struct mei_device *dev)
520 {
521 	struct mei_txe_hw *hw = to_txe_hw(dev);
522 
523 	mei_txe_br_reg_write(hw,
524 		SICR_HOST_IPC_READINESS_REQ_REG,
525 		SICR_HOST_IPC_READINESS_HOST_RDY);
526 }
527 
528 /**
529  * mei_txe_readiness_clear - clear host readiness bit
530  *
531  * @dev: the device structure
532  */
533 static void mei_txe_readiness_clear(struct mei_device *dev)
534 {
535 	struct mei_txe_hw *hw = to_txe_hw(dev);
536 
537 	mei_txe_br_reg_write(hw, SICR_HOST_IPC_READINESS_REQ_REG,
538 				SICR_HOST_IPC_READINESS_RDY_CLR);
539 }
540 /**
541  * mei_txe_readiness_get - Reads and returns
542  *	the HICR_SEC_IPC_READINESS register value
543  *
544  * @dev: the device structure
545  *
546  * Return: the HICR_SEC_IPC_READINESS register value
547  */
548 static u32 mei_txe_readiness_get(struct mei_device *dev)
549 {
550 	struct mei_txe_hw *hw = to_txe_hw(dev);
551 
552 	return mei_txe_br_reg_read(hw, HICR_SEC_IPC_READINESS_REG);
553 }
554 
555 
556 /**
557  * mei_txe_readiness_is_sec_rdy - check readiness
558  *  for HICR_SEC_IPC_READINESS_SEC_RDY
559  *
560  * @readiness: cached readiness state
561  *
562  * Return: true if readiness bit is set
563  */
564 static inline bool mei_txe_readiness_is_sec_rdy(u32 readiness)
565 {
566 	return !!(readiness & HICR_SEC_IPC_READINESS_SEC_RDY);
567 }
568 
569 /**
570  * mei_txe_hw_is_ready - check if the hw is ready
571  *
572  * @dev: the device structure
573  *
574  * Return: true if sec is ready
575  */
576 static bool mei_txe_hw_is_ready(struct mei_device *dev)
577 {
578 	u32 readiness =  mei_txe_readiness_get(dev);
579 
580 	return mei_txe_readiness_is_sec_rdy(readiness);
581 }
582 
583 /**
584  * mei_txe_host_is_ready - check if the host is ready
585  *
586  * @dev: the device structure
587  *
588  * Return: true if host is ready
589  */
590 static inline bool mei_txe_host_is_ready(struct mei_device *dev)
591 {
592 	struct mei_txe_hw *hw = to_txe_hw(dev);
593 	u32 reg = mei_txe_br_reg_read(hw, HICR_SEC_IPC_READINESS_REG);
594 
595 	return !!(reg & HICR_SEC_IPC_READINESS_HOST_RDY);
596 }
597 
598 /**
599  * mei_txe_readiness_wait - wait till readiness settles
600  *
601  * @dev: the device structure
602  *
603  * Return: 0 on success and -ETIME on timeout
604  */
605 static int mei_txe_readiness_wait(struct mei_device *dev)
606 {
607 	if (mei_txe_hw_is_ready(dev))
608 		return 0;
609 
610 	mutex_unlock(&dev->device_lock);
611 	wait_event_timeout(dev->wait_hw_ready, dev->recvd_hw_ready,
612 			msecs_to_jiffies(SEC_RESET_WAIT_TIMEOUT));
613 	mutex_lock(&dev->device_lock);
614 	if (!dev->recvd_hw_ready) {
615 		dev_err(dev->dev, "wait for readiness failed\n");
616 		return -ETIME;
617 	}
618 
619 	dev->recvd_hw_ready = false;
620 	return 0;
621 }
622 
623 static const struct mei_fw_status mei_txe_fw_sts = {
624 	.count = 2,
625 	.status[0] = PCI_CFG_TXE_FW_STS0,
626 	.status[1] = PCI_CFG_TXE_FW_STS1
627 };
628 
629 /**
630  * mei_txe_fw_status - read fw status register from pci config space
631  *
632  * @dev: mei device
633  * @fw_status: fw status register values
634  *
635  * Return: 0 on success, error otherwise
636  */
637 static int mei_txe_fw_status(struct mei_device *dev,
638 			     struct mei_fw_status *fw_status)
639 {
640 	const struct mei_fw_status *fw_src = &mei_txe_fw_sts;
641 	struct pci_dev *pdev = to_pci_dev(dev->dev);
642 	int ret;
643 	int i;
644 
645 	if (!fw_status)
646 		return -EINVAL;
647 
648 	fw_status->count = fw_src->count;
649 	for (i = 0; i < fw_src->count && i < MEI_FW_STATUS_MAX; i++) {
650 		ret = pci_read_config_dword(pdev, fw_src->status[i],
651 					    &fw_status->status[i]);
652 		trace_mei_pci_cfg_read(dev->dev, "PCI_CFG_HSF_X",
653 				       fw_src->status[i],
654 				       fw_status->status[i]);
655 		if (ret)
656 			return ret;
657 	}
658 
659 	return 0;
660 }
661 
662 /**
663  *  mei_txe_hw_config - configure hardware at the start of the devices
664  *
665  * @dev: the device structure
666  *
667  * Configure hardware at the start of the device should be done only
668  *   once at the device probe time
669  */
670 static void mei_txe_hw_config(struct mei_device *dev)
671 {
672 
673 	struct mei_txe_hw *hw = to_txe_hw(dev);
674 
675 	hw->aliveness = mei_txe_aliveness_get(dev);
676 	hw->readiness = mei_txe_readiness_get(dev);
677 
678 	dev_dbg(dev->dev, "aliveness_resp = 0x%08x, readiness = 0x%08x.\n",
679 		hw->aliveness, hw->readiness);
680 }
681 
682 /**
683  * mei_txe_write - writes a message to device.
684  *
685  * @dev: the device structure
686  * @hdr: header of message
687  * @hdr_len: header length in bytes - must multiplication of a slot (4bytes)
688  * @data: payload
689  * @data_len: paylead length in bytes
690  *
691  * Return: 0 if success, < 0 - otherwise.
692  */
693 static int mei_txe_write(struct mei_device *dev,
694 			 const void *hdr, size_t hdr_len,
695 			 const void *data, size_t data_len)
696 {
697 	struct mei_txe_hw *hw = to_txe_hw(dev);
698 	unsigned long rem;
699 	const u32 *reg_buf;
700 	u32 slots = TXE_HBUF_DEPTH;
701 	u32 dw_cnt;
702 	unsigned long i, j;
703 
704 	if (WARN_ON(!hdr || !data || hdr_len & 0x3))
705 		return -EINVAL;
706 
707 	dev_dbg(dev->dev, MEI_HDR_FMT, MEI_HDR_PRM((struct mei_msg_hdr *)hdr));
708 
709 	dw_cnt = mei_data2slots(hdr_len + data_len);
710 	if (dw_cnt > slots)
711 		return -EMSGSIZE;
712 
713 	if (WARN(!hw->aliveness, "txe write: aliveness not asserted\n"))
714 		return -EAGAIN;
715 
716 	/* Enable Input Ready Interrupt. */
717 	mei_txe_input_ready_interrupt_enable(dev);
718 
719 	if (!mei_txe_is_input_ready(dev)) {
720 		char fw_sts_str[MEI_FW_STATUS_STR_SZ];
721 
722 		mei_fw_status_str(dev, fw_sts_str, MEI_FW_STATUS_STR_SZ);
723 		dev_err(dev->dev, "Input is not ready %s\n", fw_sts_str);
724 		return -EAGAIN;
725 	}
726 
727 	reg_buf = hdr;
728 	for (i = 0; i < hdr_len / MEI_SLOT_SIZE; i++)
729 		mei_txe_input_payload_write(dev, i, reg_buf[i]);
730 
731 	reg_buf = data;
732 	for (j = 0; j < data_len / MEI_SLOT_SIZE; j++)
733 		mei_txe_input_payload_write(dev, i + j, reg_buf[j]);
734 
735 	rem = data_len & 0x3;
736 	if (rem > 0) {
737 		u32 reg = 0;
738 
739 		memcpy(&reg, (const u8 *)data + data_len - rem, rem);
740 		mei_txe_input_payload_write(dev, i + j, reg);
741 	}
742 
743 	/* after each write the whole buffer is consumed */
744 	hw->slots = 0;
745 
746 	/* Set Input-Doorbell */
747 	mei_txe_input_doorbell_set(hw);
748 
749 	return 0;
750 }
751 
752 /**
753  * mei_txe_hbuf_depth - mimics the me hbuf circular buffer
754  *
755  * @dev: the device structure
756  *
757  * Return: the TXE_HBUF_DEPTH
758  */
759 static u32 mei_txe_hbuf_depth(const struct mei_device *dev)
760 {
761 	return TXE_HBUF_DEPTH;
762 }
763 
764 /**
765  * mei_txe_hbuf_empty_slots - mimics the me hbuf circular buffer
766  *
767  * @dev: the device structure
768  *
769  * Return: always TXE_HBUF_DEPTH
770  */
771 static int mei_txe_hbuf_empty_slots(struct mei_device *dev)
772 {
773 	struct mei_txe_hw *hw = to_txe_hw(dev);
774 
775 	return hw->slots;
776 }
777 
778 /**
779  * mei_txe_count_full_read_slots - mimics the me device circular buffer
780  *
781  * @dev: the device structure
782  *
783  * Return: always buffer size in dwords count
784  */
785 static int mei_txe_count_full_read_slots(struct mei_device *dev)
786 {
787 	/* read buffers has static size */
788 	return TXE_HBUF_DEPTH;
789 }
790 
791 /**
792  * mei_txe_read_hdr - read message header which is always in 4 first bytes
793  *
794  * @dev: the device structure
795  *
796  * Return: mei message header
797  */
798 
799 static u32 mei_txe_read_hdr(const struct mei_device *dev)
800 {
801 	return mei_txe_out_data_read(dev, 0);
802 }
803 /**
804  * mei_txe_read - reads a message from the txe device.
805  *
806  * @dev: the device structure
807  * @buf: message buffer will be written
808  * @len: message size will be read
809  *
810  * Return: -EINVAL on error wrong argument and 0 on success
811  */
812 static int mei_txe_read(struct mei_device *dev,
813 		unsigned char *buf, unsigned long len)
814 {
815 
816 	struct mei_txe_hw *hw = to_txe_hw(dev);
817 	u32 *reg_buf, reg;
818 	u32 rem;
819 	u32 i;
820 
821 	if (WARN_ON(!buf || !len))
822 		return -EINVAL;
823 
824 	reg_buf = (u32 *)buf;
825 	rem = len & 0x3;
826 
827 	dev_dbg(dev->dev, "buffer-length = %lu buf[0]0x%08X\n",
828 		len, mei_txe_out_data_read(dev, 0));
829 
830 	for (i = 0; i < len / MEI_SLOT_SIZE; i++) {
831 		/* skip header: index starts from 1 */
832 		reg = mei_txe_out_data_read(dev, i + 1);
833 		dev_dbg(dev->dev, "buf[%d] = 0x%08X\n", i, reg);
834 		*reg_buf++ = reg;
835 	}
836 
837 	if (rem) {
838 		reg = mei_txe_out_data_read(dev, i + 1);
839 		memcpy(reg_buf, &reg, rem);
840 	}
841 
842 	mei_txe_output_ready_set(hw);
843 	return 0;
844 }
845 
846 /**
847  * mei_txe_hw_reset - resets host and fw.
848  *
849  * @dev: the device structure
850  * @intr_enable: if interrupt should be enabled after reset.
851  *
852  * Return: 0 on success and < 0 in case of error
853  */
854 static int mei_txe_hw_reset(struct mei_device *dev, bool intr_enable)
855 {
856 	struct mei_txe_hw *hw = to_txe_hw(dev);
857 
858 	u32 aliveness_req;
859 	/*
860 	 * read input doorbell to ensure consistency between  Bridge and SeC
861 	 * return value might be garbage return
862 	 */
863 	(void)mei_txe_sec_reg_read_silent(hw, SEC_IPC_INPUT_DOORBELL_REG);
864 
865 	aliveness_req = mei_txe_aliveness_req_get(dev);
866 	hw->aliveness = mei_txe_aliveness_get(dev);
867 
868 	/* Disable interrupts in this stage we will poll */
869 	mei_txe_intr_disable(dev);
870 
871 	/*
872 	 * If Aliveness Request and Aliveness Response are not equal then
873 	 * wait for them to be equal
874 	 * Since we might have interrupts disabled - poll for it
875 	 */
876 	if (aliveness_req != hw->aliveness)
877 		if (mei_txe_aliveness_poll(dev, aliveness_req) < 0) {
878 			dev_err(dev->dev, "wait for aliveness settle failed ... bailing out\n");
879 			return -EIO;
880 		}
881 
882 	/*
883 	 * If Aliveness Request and Aliveness Response are set then clear them
884 	 */
885 	if (aliveness_req) {
886 		mei_txe_aliveness_set(dev, 0);
887 		if (mei_txe_aliveness_poll(dev, 0) < 0) {
888 			dev_err(dev->dev, "wait for aliveness failed ... bailing out\n");
889 			return -EIO;
890 		}
891 	}
892 
893 	/*
894 	 * Set readiness RDY_CLR bit
895 	 */
896 	mei_txe_readiness_clear(dev);
897 
898 	return 0;
899 }
900 
901 /**
902  * mei_txe_hw_start - start the hardware after reset
903  *
904  * @dev: the device structure
905  *
906  * Return: 0 on success an error code otherwise
907  */
908 static int mei_txe_hw_start(struct mei_device *dev)
909 {
910 	struct mei_txe_hw *hw = to_txe_hw(dev);
911 	int ret;
912 
913 	u32 hisr;
914 
915 	/* bring back interrupts */
916 	mei_txe_intr_enable(dev);
917 
918 	ret = mei_txe_readiness_wait(dev);
919 	if (ret < 0) {
920 		dev_err(dev->dev, "waiting for readiness failed\n");
921 		return ret;
922 	}
923 
924 	/*
925 	 * If HISR.INT2_STS interrupt status bit is set then clear it.
926 	 */
927 	hisr = mei_txe_br_reg_read(hw, HISR_REG);
928 	if (hisr & HISR_INT_2_STS)
929 		mei_txe_br_reg_write(hw, HISR_REG, HISR_INT_2_STS);
930 
931 	/* Clear the interrupt cause of OutputDoorbell */
932 	clear_bit(TXE_INTR_OUT_DB_BIT, &hw->intr_cause);
933 
934 	ret = mei_txe_aliveness_set_sync(dev, 1);
935 	if (ret < 0) {
936 		dev_err(dev->dev, "wait for aliveness failed ... bailing out\n");
937 		return ret;
938 	}
939 
940 	pm_runtime_set_active(dev->dev);
941 
942 	/* enable input ready interrupts:
943 	 * SEC_IPC_HOST_INT_MASK.IPC_INPUT_READY_INT_MASK
944 	 */
945 	mei_txe_input_ready_interrupt_enable(dev);
946 
947 
948 	/*  Set the SICR_SEC_IPC_OUTPUT_STATUS.IPC_OUTPUT_READY bit */
949 	mei_txe_output_ready_set(hw);
950 
951 	/* Set bit SICR_HOST_IPC_READINESS.HOST_RDY
952 	 */
953 	mei_txe_readiness_set_host_rdy(dev);
954 
955 	return 0;
956 }
957 
958 /**
959  * mei_txe_check_and_ack_intrs - translate multi BAR interrupt into
960  *  single bit mask and acknowledge the interrupts
961  *
962  * @dev: the device structure
963  * @do_ack: acknowledge interrupts
964  *
965  * Return: true if found interrupts to process.
966  */
967 static bool mei_txe_check_and_ack_intrs(struct mei_device *dev, bool do_ack)
968 {
969 	struct mei_txe_hw *hw = to_txe_hw(dev);
970 	u32 hisr;
971 	u32 hhisr;
972 	u32 ipc_isr;
973 	u32 aliveness;
974 	bool generated;
975 
976 	/* read interrupt registers */
977 	hhisr = mei_txe_br_reg_read(hw, HHISR_REG);
978 	generated = (hhisr & IPC_HHIER_MSK);
979 	if (!generated)
980 		goto out;
981 
982 	hisr = mei_txe_br_reg_read(hw, HISR_REG);
983 
984 	aliveness = mei_txe_aliveness_get(dev);
985 	if (hhisr & IPC_HHIER_SEC && aliveness) {
986 		ipc_isr = mei_txe_sec_reg_read_silent(hw,
987 				SEC_IPC_HOST_INT_STATUS_REG);
988 	} else {
989 		ipc_isr = 0;
990 		hhisr &= ~IPC_HHIER_SEC;
991 	}
992 
993 	generated = generated ||
994 		(hisr & HISR_INT_STS_MSK) ||
995 		(ipc_isr & SEC_IPC_HOST_INT_STATUS_PENDING);
996 
997 	if (generated && do_ack) {
998 		/* Save the interrupt causes */
999 		hw->intr_cause |= hisr & HISR_INT_STS_MSK;
1000 		if (ipc_isr & SEC_IPC_HOST_INT_STATUS_IN_RDY)
1001 			hw->intr_cause |= TXE_INTR_IN_READY;
1002 
1003 
1004 		mei_txe_intr_disable(dev);
1005 		/* Clear the interrupts in hierarchy:
1006 		 * IPC and Bridge, than the High Level */
1007 		mei_txe_sec_reg_write_silent(hw,
1008 			SEC_IPC_HOST_INT_STATUS_REG, ipc_isr);
1009 		mei_txe_br_reg_write(hw, HISR_REG, hisr);
1010 		mei_txe_br_reg_write(hw, HHISR_REG, hhisr);
1011 	}
1012 
1013 out:
1014 	return generated;
1015 }
1016 
1017 /**
1018  * mei_txe_irq_quick_handler - The ISR of the MEI device
1019  *
1020  * @irq: The irq number
1021  * @dev_id: pointer to the device structure
1022  *
1023  * Return: IRQ_WAKE_THREAD if interrupt is designed for the device
1024  *         IRQ_NONE otherwise
1025  */
1026 irqreturn_t mei_txe_irq_quick_handler(int irq, void *dev_id)
1027 {
1028 	struct mei_device *dev = dev_id;
1029 
1030 	if (mei_txe_check_and_ack_intrs(dev, true))
1031 		return IRQ_WAKE_THREAD;
1032 	return IRQ_NONE;
1033 }
1034 
1035 
1036 /**
1037  * mei_txe_irq_thread_handler - txe interrupt thread
1038  *
1039  * @irq: The irq number
1040  * @dev_id: pointer to the device structure
1041  *
1042  * Return: IRQ_HANDLED
1043  */
1044 irqreturn_t mei_txe_irq_thread_handler(int irq, void *dev_id)
1045 {
1046 	struct mei_device *dev = (struct mei_device *) dev_id;
1047 	struct mei_txe_hw *hw = to_txe_hw(dev);
1048 	struct list_head cmpl_list;
1049 	s32 slots;
1050 	int rets = 0;
1051 
1052 	dev_dbg(dev->dev, "irq thread: Interrupt Registers HHISR|HISR|SEC=%02X|%04X|%02X\n",
1053 		mei_txe_br_reg_read(hw, HHISR_REG),
1054 		mei_txe_br_reg_read(hw, HISR_REG),
1055 		mei_txe_sec_reg_read_silent(hw, SEC_IPC_HOST_INT_STATUS_REG));
1056 
1057 
1058 	/* initialize our complete list */
1059 	mutex_lock(&dev->device_lock);
1060 	INIT_LIST_HEAD(&cmpl_list);
1061 
1062 	if (pci_dev_msi_enabled(to_pci_dev(dev->dev)))
1063 		mei_txe_check_and_ack_intrs(dev, true);
1064 
1065 	/* show irq events */
1066 	mei_txe_pending_interrupts(dev);
1067 
1068 	hw->aliveness = mei_txe_aliveness_get(dev);
1069 	hw->readiness = mei_txe_readiness_get(dev);
1070 
1071 	/* Readiness:
1072 	 * Detection of TXE driver going through reset
1073 	 * or TXE driver resetting the HECI interface.
1074 	 */
1075 	if (test_and_clear_bit(TXE_INTR_READINESS_BIT, &hw->intr_cause)) {
1076 		dev_dbg(dev->dev, "Readiness Interrupt was received...\n");
1077 
1078 		/* Check if SeC is going through reset */
1079 		if (mei_txe_readiness_is_sec_rdy(hw->readiness)) {
1080 			dev_dbg(dev->dev, "we need to start the dev.\n");
1081 			dev->recvd_hw_ready = true;
1082 		} else {
1083 			dev->recvd_hw_ready = false;
1084 			if (dev->dev_state != MEI_DEV_RESETTING) {
1085 
1086 				dev_warn(dev->dev, "FW not ready: resetting.\n");
1087 				schedule_work(&dev->reset_work);
1088 				goto end;
1089 
1090 			}
1091 		}
1092 		wake_up(&dev->wait_hw_ready);
1093 	}
1094 
1095 	/************************************************************/
1096 	/* Check interrupt cause:
1097 	 * Aliveness: Detection of SeC acknowledge of host request that
1098 	 * it remain alive or host cancellation of that request.
1099 	 */
1100 
1101 	if (test_and_clear_bit(TXE_INTR_ALIVENESS_BIT, &hw->intr_cause)) {
1102 		/* Clear the interrupt cause */
1103 		dev_dbg(dev->dev,
1104 			"Aliveness Interrupt: Status: %d\n", hw->aliveness);
1105 		dev->pg_event = MEI_PG_EVENT_RECEIVED;
1106 		if (waitqueue_active(&hw->wait_aliveness_resp))
1107 			wake_up(&hw->wait_aliveness_resp);
1108 	}
1109 
1110 
1111 	/* Output Doorbell:
1112 	 * Detection of SeC having sent output to host
1113 	 */
1114 	slots = mei_count_full_read_slots(dev);
1115 	if (test_and_clear_bit(TXE_INTR_OUT_DB_BIT, &hw->intr_cause)) {
1116 		/* Read from TXE */
1117 		rets = mei_irq_read_handler(dev, &cmpl_list, &slots);
1118 		if (rets &&
1119 		    (dev->dev_state != MEI_DEV_RESETTING &&
1120 		     dev->dev_state != MEI_DEV_POWER_DOWN)) {
1121 			dev_err(dev->dev,
1122 				"mei_irq_read_handler ret = %d.\n", rets);
1123 
1124 			schedule_work(&dev->reset_work);
1125 			goto end;
1126 		}
1127 	}
1128 	/* Input Ready: Detection if host can write to SeC */
1129 	if (test_and_clear_bit(TXE_INTR_IN_READY_BIT, &hw->intr_cause)) {
1130 		dev->hbuf_is_ready = true;
1131 		hw->slots = TXE_HBUF_DEPTH;
1132 	}
1133 
1134 	if (hw->aliveness && dev->hbuf_is_ready) {
1135 		/* get the real register value */
1136 		dev->hbuf_is_ready = mei_hbuf_is_ready(dev);
1137 		rets = mei_irq_write_handler(dev, &cmpl_list);
1138 		if (rets && rets != -EMSGSIZE)
1139 			dev_err(dev->dev, "mei_irq_write_handler ret = %d.\n",
1140 				rets);
1141 		dev->hbuf_is_ready = mei_hbuf_is_ready(dev);
1142 	}
1143 
1144 	mei_irq_compl_handler(dev, &cmpl_list);
1145 
1146 end:
1147 	dev_dbg(dev->dev, "interrupt thread end ret = %d\n", rets);
1148 
1149 	mutex_unlock(&dev->device_lock);
1150 
1151 	mei_enable_interrupts(dev);
1152 	return IRQ_HANDLED;
1153 }
1154 
1155 static const struct mei_hw_ops mei_txe_hw_ops = {
1156 
1157 	.host_is_ready = mei_txe_host_is_ready,
1158 
1159 	.fw_status = mei_txe_fw_status,
1160 	.pg_state = mei_txe_pg_state,
1161 
1162 	.hw_is_ready = mei_txe_hw_is_ready,
1163 	.hw_reset = mei_txe_hw_reset,
1164 	.hw_config = mei_txe_hw_config,
1165 	.hw_start = mei_txe_hw_start,
1166 
1167 	.pg_in_transition = mei_txe_pg_in_transition,
1168 	.pg_is_enabled = mei_txe_pg_is_enabled,
1169 
1170 	.intr_clear = mei_txe_intr_clear,
1171 	.intr_enable = mei_txe_intr_enable,
1172 	.intr_disable = mei_txe_intr_disable,
1173 	.synchronize_irq = mei_txe_synchronize_irq,
1174 
1175 	.hbuf_free_slots = mei_txe_hbuf_empty_slots,
1176 	.hbuf_is_ready = mei_txe_is_input_ready,
1177 	.hbuf_depth = mei_txe_hbuf_depth,
1178 
1179 	.write = mei_txe_write,
1180 
1181 	.rdbuf_full_slots = mei_txe_count_full_read_slots,
1182 	.read_hdr = mei_txe_read_hdr,
1183 
1184 	.read = mei_txe_read,
1185 
1186 };
1187 
1188 /**
1189  * mei_txe_dev_init - allocates and initializes txe hardware specific structure
1190  *
1191  * @pdev: pci device
1192  *
1193  * Return: struct mei_device * on success or NULL
1194  */
1195 struct mei_device *mei_txe_dev_init(struct pci_dev *pdev)
1196 {
1197 	struct mei_device *dev;
1198 	struct mei_txe_hw *hw;
1199 
1200 	dev = devm_kzalloc(&pdev->dev, sizeof(struct mei_device) +
1201 			   sizeof(struct mei_txe_hw), GFP_KERNEL);
1202 	if (!dev)
1203 		return NULL;
1204 
1205 	mei_device_init(dev, &pdev->dev, &mei_txe_hw_ops);
1206 
1207 	hw = to_txe_hw(dev);
1208 
1209 	init_waitqueue_head(&hw->wait_aliveness_resp);
1210 
1211 	return dev;
1212 }
1213 
1214 /**
1215  * mei_txe_setup_satt2 - SATT2 configuration for DMA support.
1216  *
1217  * @dev:   the device structure
1218  * @addr:  physical address start of the range
1219  * @range: physical range size
1220  *
1221  * Return: 0 on success an error code otherwise
1222  */
1223 int mei_txe_setup_satt2(struct mei_device *dev, phys_addr_t addr, u32 range)
1224 {
1225 	struct mei_txe_hw *hw = to_txe_hw(dev);
1226 
1227 	u32 lo32 = lower_32_bits(addr);
1228 	u32 hi32 = upper_32_bits(addr);
1229 	u32 ctrl;
1230 
1231 	/* SATT is limited to 36 Bits */
1232 	if (hi32 & ~0xF)
1233 		return -EINVAL;
1234 
1235 	/* SATT has to be 16Byte aligned */
1236 	if (lo32 & 0xF)
1237 		return -EINVAL;
1238 
1239 	/* SATT range has to be 4Bytes aligned */
1240 	if (range & 0x4)
1241 		return -EINVAL;
1242 
1243 	/* SATT is limited to 32 MB range*/
1244 	if (range > SATT_RANGE_MAX)
1245 		return -EINVAL;
1246 
1247 	ctrl = SATT2_CTRL_VALID_MSK;
1248 	ctrl |= hi32  << SATT2_CTRL_BR_BASE_ADDR_REG_SHIFT;
1249 
1250 	mei_txe_br_reg_write(hw, SATT2_SAP_SIZE_REG, range);
1251 	mei_txe_br_reg_write(hw, SATT2_BRG_BA_LSB_REG, lo32);
1252 	mei_txe_br_reg_write(hw, SATT2_CTRL_REG, ctrl);
1253 	dev_dbg(dev->dev, "SATT2: SAP_SIZE_OFFSET=0x%08X, BRG_BA_LSB_OFFSET=0x%08X, CTRL_OFFSET=0x%08X\n",
1254 		range, lo32, ctrl);
1255 
1256 	return 0;
1257 }
1258