xref: /linux/drivers/misc/mei/hbm.c (revision 26ec99b105d5d1465fffed563cfe1a90a7b150fd)
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/export.h>
18 #include <linux/sched.h>
19 #include <linux/wait.h>
20 #include <linux/pm_runtime.h>
21 #include <linux/slab.h>
22 
23 #include <linux/mei.h>
24 
25 #include "mei_dev.h"
26 #include "hbm.h"
27 #include "client.h"
28 
29 static const char *mei_hbm_status_str(enum mei_hbm_status status)
30 {
31 #define MEI_HBM_STATUS(status) case MEI_HBMS_##status: return #status
32 	switch (status) {
33 	MEI_HBM_STATUS(SUCCESS);
34 	MEI_HBM_STATUS(CLIENT_NOT_FOUND);
35 	MEI_HBM_STATUS(ALREADY_EXISTS);
36 	MEI_HBM_STATUS(REJECTED);
37 	MEI_HBM_STATUS(INVALID_PARAMETER);
38 	MEI_HBM_STATUS(NOT_ALLOWED);
39 	MEI_HBM_STATUS(ALREADY_STARTED);
40 	MEI_HBM_STATUS(NOT_STARTED);
41 	default: return "unknown";
42 	}
43 #undef MEI_HBM_STATUS
44 };
45 
46 static const char *mei_cl_conn_status_str(enum mei_cl_connect_status status)
47 {
48 #define MEI_CL_CS(status) case MEI_CL_CONN_##status: return #status
49 	switch (status) {
50 	MEI_CL_CS(SUCCESS);
51 	MEI_CL_CS(NOT_FOUND);
52 	MEI_CL_CS(ALREADY_STARTED);
53 	MEI_CL_CS(OUT_OF_RESOURCES);
54 	MEI_CL_CS(MESSAGE_SMALL);
55 	MEI_CL_CS(NOT_ALLOWED);
56 	default: return "unknown";
57 	}
58 #undef MEI_CL_CCS
59 }
60 
61 const char *mei_hbm_state_str(enum mei_hbm_state state)
62 {
63 #define MEI_HBM_STATE(state) case MEI_HBM_##state: return #state
64 	switch (state) {
65 	MEI_HBM_STATE(IDLE);
66 	MEI_HBM_STATE(STARTING);
67 	MEI_HBM_STATE(STARTED);
68 	MEI_HBM_STATE(ENUM_CLIENTS);
69 	MEI_HBM_STATE(CLIENT_PROPERTIES);
70 	MEI_HBM_STATE(STOPPED);
71 	default:
72 		return "unknown";
73 	}
74 #undef MEI_HBM_STATE
75 }
76 
77 /**
78  * mei_cl_conn_status_to_errno - convert client connect response
79  * status to error code
80  *
81  * @status: client connect response status
82  *
83  * Return: corresponding error code
84  */
85 static int mei_cl_conn_status_to_errno(enum mei_cl_connect_status status)
86 {
87 	switch (status) {
88 	case MEI_CL_CONN_SUCCESS:          return 0;
89 	case MEI_CL_CONN_NOT_FOUND:        return -ENOTTY;
90 	case MEI_CL_CONN_ALREADY_STARTED:  return -EBUSY;
91 	case MEI_CL_CONN_OUT_OF_RESOURCES: return -EBUSY;
92 	case MEI_CL_CONN_MESSAGE_SMALL:    return -EINVAL;
93 	case MEI_CL_CONN_NOT_ALLOWED:      return -EBUSY;
94 	default:                           return -EINVAL;
95 	}
96 }
97 
98 /**
99  * mei_hbm_idle - set hbm to idle state
100  *
101  * @dev: the device structure
102  */
103 void mei_hbm_idle(struct mei_device *dev)
104 {
105 	dev->init_clients_timer = 0;
106 	dev->hbm_state = MEI_HBM_IDLE;
107 }
108 
109 /**
110  * mei_hbm_reset - reset hbm counters and book keeping data structurs
111  *
112  * @dev: the device structure
113  */
114 void mei_hbm_reset(struct mei_device *dev)
115 {
116 	mei_me_cl_rm_all(dev);
117 
118 	mei_hbm_idle(dev);
119 }
120 
121 /**
122  * mei_hbm_hdr - construct hbm header
123  *
124  * @hdr: hbm header
125  * @length: payload length
126  */
127 
128 static inline void mei_hbm_hdr(struct mei_msg_hdr *hdr, size_t length)
129 {
130 	hdr->host_addr = 0;
131 	hdr->me_addr = 0;
132 	hdr->length = length;
133 	hdr->msg_complete = 1;
134 	hdr->reserved = 0;
135 	hdr->internal = 0;
136 }
137 
138 /**
139  * mei_hbm_cl_hdr - construct client hbm header
140  *
141  * @cl: client
142  * @hbm_cmd: host bus message command
143  * @buf: buffer for cl header
144  * @len: buffer length
145  */
146 static inline
147 void mei_hbm_cl_hdr(struct mei_cl *cl, u8 hbm_cmd, void *buf, size_t len)
148 {
149 	struct mei_hbm_cl_cmd *cmd = buf;
150 
151 	memset(cmd, 0, len);
152 
153 	cmd->hbm_cmd = hbm_cmd;
154 	cmd->host_addr = mei_cl_host_addr(cl);
155 	cmd->me_addr = mei_cl_me_id(cl);
156 }
157 
158 /**
159  * mei_hbm_cl_write - write simple hbm client message
160  *
161  * @dev: the device structure
162  * @cl: client
163  * @hbm_cmd: host bus message command
164  * @buf: message buffer
165  * @len: buffer length
166  *
167  * Return: 0 on success, <0 on failure.
168  */
169 static inline
170 int mei_hbm_cl_write(struct mei_device *dev, struct mei_cl *cl,
171 		     u8 hbm_cmd, u8 *buf, size_t len)
172 {
173 	struct mei_msg_hdr mei_hdr;
174 
175 	mei_hbm_hdr(&mei_hdr, len);
176 	mei_hbm_cl_hdr(cl, hbm_cmd, buf, len);
177 
178 	return mei_write_message(dev, &mei_hdr, buf);
179 }
180 
181 /**
182  * mei_hbm_cl_addr_equal - check if the client's and
183  *	the message address match
184  *
185  * @cl: client
186  * @cmd: hbm client message
187  *
188  * Return: true if addresses are the same
189  */
190 static inline
191 bool mei_hbm_cl_addr_equal(struct mei_cl *cl, struct mei_hbm_cl_cmd *cmd)
192 {
193 	return  mei_cl_host_addr(cl) == cmd->host_addr &&
194 		mei_cl_me_id(cl) == cmd->me_addr;
195 }
196 
197 /**
198  * mei_hbm_cl_find_by_cmd - find recipient client
199  *
200  * @dev: the device structure
201  * @buf: a buffer with hbm cl command
202  *
203  * Return: the recipient client or NULL if not found
204  */
205 static inline
206 struct mei_cl *mei_hbm_cl_find_by_cmd(struct mei_device *dev, void *buf)
207 {
208 	struct mei_hbm_cl_cmd *cmd = (struct mei_hbm_cl_cmd *)buf;
209 	struct mei_cl *cl;
210 
211 	list_for_each_entry(cl, &dev->file_list, link)
212 		if (mei_hbm_cl_addr_equal(cl, cmd))
213 			return cl;
214 	return NULL;
215 }
216 
217 
218 /**
219  * mei_hbm_start_wait - wait for start response message.
220  *
221  * @dev: the device structure
222  *
223  * Return: 0 on success and < 0 on failure
224  */
225 int mei_hbm_start_wait(struct mei_device *dev)
226 {
227 	int ret;
228 
229 	if (dev->hbm_state > MEI_HBM_STARTING)
230 		return 0;
231 
232 	mutex_unlock(&dev->device_lock);
233 	ret = wait_event_timeout(dev->wait_hbm_start,
234 			dev->hbm_state != MEI_HBM_STARTING,
235 			mei_secs_to_jiffies(MEI_HBM_TIMEOUT));
236 	mutex_lock(&dev->device_lock);
237 
238 	if (ret == 0 && (dev->hbm_state <= MEI_HBM_STARTING)) {
239 		dev->hbm_state = MEI_HBM_IDLE;
240 		dev_err(dev->dev, "waiting for mei start failed\n");
241 		return -ETIME;
242 	}
243 	return 0;
244 }
245 
246 /**
247  * mei_hbm_start_req - sends start request message.
248  *
249  * @dev: the device structure
250  *
251  * Return: 0 on success and < 0 on failure
252  */
253 int mei_hbm_start_req(struct mei_device *dev)
254 {
255 	struct mei_msg_hdr mei_hdr;
256 	struct hbm_host_version_request start_req;
257 	const size_t len = sizeof(struct hbm_host_version_request);
258 	int ret;
259 
260 	mei_hbm_reset(dev);
261 
262 	mei_hbm_hdr(&mei_hdr, len);
263 
264 	/* host start message */
265 	memset(&start_req, 0, len);
266 	start_req.hbm_cmd = HOST_START_REQ_CMD;
267 	start_req.host_version.major_version = HBM_MAJOR_VERSION;
268 	start_req.host_version.minor_version = HBM_MINOR_VERSION;
269 
270 	dev->hbm_state = MEI_HBM_IDLE;
271 	ret = mei_write_message(dev, &mei_hdr, &start_req);
272 	if (ret) {
273 		dev_err(dev->dev, "version message write failed: ret = %d\n",
274 			ret);
275 		return ret;
276 	}
277 
278 	dev->hbm_state = MEI_HBM_STARTING;
279 	dev->init_clients_timer = MEI_CLIENTS_INIT_TIMEOUT;
280 	return 0;
281 }
282 
283 /**
284  * mei_hbm_enum_clients_req - sends enumeration client request message.
285  *
286  * @dev: the device structure
287  *
288  * Return: 0 on success and < 0 on failure
289  */
290 static int mei_hbm_enum_clients_req(struct mei_device *dev)
291 {
292 	struct mei_msg_hdr mei_hdr;
293 	struct hbm_host_enum_request enum_req;
294 	const size_t len = sizeof(struct hbm_host_enum_request);
295 	int ret;
296 
297 	/* enumerate clients */
298 	mei_hbm_hdr(&mei_hdr, len);
299 
300 	memset(&enum_req, 0, len);
301 	enum_req.hbm_cmd = HOST_ENUM_REQ_CMD;
302 	enum_req.flags |= dev->hbm_f_dc_supported ?
303 			  MEI_HBM_ENUM_F_ALLOW_ADD : 0;
304 	enum_req.flags |= dev->hbm_f_ie_supported ?
305 			  MEI_HBM_ENUM_F_IMMEDIATE_ENUM : 0;
306 
307 	ret = mei_write_message(dev, &mei_hdr, &enum_req);
308 	if (ret) {
309 		dev_err(dev->dev, "enumeration request write failed: ret = %d.\n",
310 			ret);
311 		return ret;
312 	}
313 	dev->hbm_state = MEI_HBM_ENUM_CLIENTS;
314 	dev->init_clients_timer = MEI_CLIENTS_INIT_TIMEOUT;
315 	return 0;
316 }
317 
318 /**
319  * mei_hbm_me_cl_add - add new me client to the list
320  *
321  * @dev: the device structure
322  * @res: hbm property response
323  *
324  * Return: 0 on success and -ENOMEM on allocation failure
325  */
326 
327 static int mei_hbm_me_cl_add(struct mei_device *dev,
328 			     struct hbm_props_response *res)
329 {
330 	struct mei_me_client *me_cl;
331 	const uuid_le *uuid = &res->client_properties.protocol_name;
332 
333 	mei_me_cl_rm_by_uuid(dev, uuid);
334 
335 	me_cl = kzalloc(sizeof(struct mei_me_client), GFP_KERNEL);
336 	if (!me_cl)
337 		return -ENOMEM;
338 
339 	mei_me_cl_init(me_cl);
340 
341 	me_cl->props = res->client_properties;
342 	me_cl->client_id = res->me_addr;
343 	me_cl->tx_flow_ctrl_creds = 0;
344 
345 	mei_me_cl_add(dev, me_cl);
346 
347 	return 0;
348 }
349 
350 /**
351  * mei_hbm_add_cl_resp - send response to fw on client add request
352  *
353  * @dev: the device structure
354  * @addr: me address
355  * @status: response status
356  *
357  * Return: 0 on success and < 0 on failure
358  */
359 static int mei_hbm_add_cl_resp(struct mei_device *dev, u8 addr, u8 status)
360 {
361 	struct mei_msg_hdr mei_hdr;
362 	struct hbm_add_client_response resp;
363 	const size_t len = sizeof(struct hbm_add_client_response);
364 	int ret;
365 
366 	dev_dbg(dev->dev, "adding client response\n");
367 
368 	mei_hbm_hdr(&mei_hdr, len);
369 
370 	memset(&resp, 0, sizeof(struct hbm_add_client_response));
371 	resp.hbm_cmd = MEI_HBM_ADD_CLIENT_RES_CMD;
372 	resp.me_addr = addr;
373 	resp.status  = status;
374 
375 	ret = mei_write_message(dev, &mei_hdr, &resp);
376 	if (ret)
377 		dev_err(dev->dev, "add client response write failed: ret = %d\n",
378 			ret);
379 	return ret;
380 }
381 
382 /**
383  * mei_hbm_fw_add_cl_req - request from the fw to add a client
384  *
385  * @dev: the device structure
386  * @req: add client request
387  *
388  * Return: 0 on success and < 0 on failure
389  */
390 static int mei_hbm_fw_add_cl_req(struct mei_device *dev,
391 			      struct hbm_add_client_request *req)
392 {
393 	int ret;
394 	u8 status = MEI_HBMS_SUCCESS;
395 
396 	BUILD_BUG_ON(sizeof(struct hbm_add_client_request) !=
397 			sizeof(struct hbm_props_response));
398 
399 	ret = mei_hbm_me_cl_add(dev, (struct hbm_props_response *)req);
400 	if (ret)
401 		status = !MEI_HBMS_SUCCESS;
402 
403 	if (dev->dev_state == MEI_DEV_ENABLED)
404 		schedule_work(&dev->bus_rescan_work);
405 
406 	return mei_hbm_add_cl_resp(dev, req->me_addr, status);
407 }
408 
409 /**
410  * mei_hbm_cl_notify_req - send notification request
411  *
412  * @dev: the device structure
413  * @cl: a client to disconnect from
414  * @start: true for start false for stop
415  *
416  * Return: 0 on success and -EIO on write failure
417  */
418 int mei_hbm_cl_notify_req(struct mei_device *dev,
419 			  struct mei_cl *cl, u8 start)
420 {
421 
422 	struct mei_msg_hdr mei_hdr;
423 	struct hbm_notification_request req;
424 	const size_t len = sizeof(struct hbm_notification_request);
425 	int ret;
426 
427 	mei_hbm_hdr(&mei_hdr, len);
428 	mei_hbm_cl_hdr(cl, MEI_HBM_NOTIFY_REQ_CMD, &req, len);
429 
430 	req.start = start;
431 
432 	ret = mei_write_message(dev, &mei_hdr, &req);
433 	if (ret)
434 		dev_err(dev->dev, "notify request failed: ret = %d\n", ret);
435 
436 	return ret;
437 }
438 
439 /**
440  *  notify_res_to_fop - convert notification response to the proper
441  *      notification FOP
442  *
443  * @cmd: client notification start response command
444  *
445  * Return:  MEI_FOP_NOTIFY_START or MEI_FOP_NOTIFY_STOP;
446  */
447 static inline enum mei_cb_file_ops notify_res_to_fop(struct mei_hbm_cl_cmd *cmd)
448 {
449 	struct hbm_notification_response *rs =
450 		(struct hbm_notification_response *)cmd;
451 
452 	return mei_cl_notify_req2fop(rs->start);
453 }
454 
455 /**
456  * mei_hbm_cl_notify_start_res - update the client state according
457  *       notify start response
458  *
459  * @dev: the device structure
460  * @cl: mei host client
461  * @cmd: client notification start response command
462  */
463 static void mei_hbm_cl_notify_start_res(struct mei_device *dev,
464 					struct mei_cl *cl,
465 					struct mei_hbm_cl_cmd *cmd)
466 {
467 	struct hbm_notification_response *rs =
468 		(struct hbm_notification_response *)cmd;
469 
470 	cl_dbg(dev, cl, "hbm: notify start response status=%d\n", rs->status);
471 
472 	if (rs->status == MEI_HBMS_SUCCESS ||
473 	    rs->status == MEI_HBMS_ALREADY_STARTED) {
474 		cl->notify_en = true;
475 		cl->status = 0;
476 	} else {
477 		cl->status = -EINVAL;
478 	}
479 }
480 
481 /**
482  * mei_hbm_cl_notify_stop_res - update the client state according
483  *       notify stop response
484  *
485  * @dev: the device structure
486  * @cl: mei host client
487  * @cmd: client notification stop response command
488  */
489 static void mei_hbm_cl_notify_stop_res(struct mei_device *dev,
490 				       struct mei_cl *cl,
491 				       struct mei_hbm_cl_cmd *cmd)
492 {
493 	struct hbm_notification_response *rs =
494 		(struct hbm_notification_response *)cmd;
495 
496 	cl_dbg(dev, cl, "hbm: notify stop response status=%d\n", rs->status);
497 
498 	if (rs->status == MEI_HBMS_SUCCESS ||
499 	    rs->status == MEI_HBMS_NOT_STARTED) {
500 		cl->notify_en = false;
501 		cl->status = 0;
502 	} else {
503 		/* TODO: spec is not clear yet about other possible issues */
504 		cl->status = -EINVAL;
505 	}
506 }
507 
508 /**
509  * mei_hbm_cl_notify - signal notification event
510  *
511  * @dev: the device structure
512  * @cmd: notification client message
513  */
514 static void mei_hbm_cl_notify(struct mei_device *dev,
515 			      struct mei_hbm_cl_cmd *cmd)
516 {
517 	struct mei_cl *cl;
518 
519 	cl = mei_hbm_cl_find_by_cmd(dev, cmd);
520 	if (cl)
521 		mei_cl_notify(cl);
522 }
523 
524 /**
525  * mei_hbm_prop_req - request property for a single client
526  *
527  * @dev: the device structure
528  * @start_idx: client index to start search
529  *
530  * Return: 0 on success and < 0 on failure
531  */
532 static int mei_hbm_prop_req(struct mei_device *dev, unsigned long start_idx)
533 {
534 	struct mei_msg_hdr mei_hdr;
535 	struct hbm_props_request prop_req;
536 	const size_t len = sizeof(struct hbm_props_request);
537 	unsigned long addr;
538 	int ret;
539 
540 	addr = find_next_bit(dev->me_clients_map, MEI_CLIENTS_MAX, start_idx);
541 
542 	/* We got all client properties */
543 	if (addr == MEI_CLIENTS_MAX) {
544 		dev->hbm_state = MEI_HBM_STARTED;
545 		mei_host_client_init(dev);
546 
547 		return 0;
548 	}
549 
550 	mei_hbm_hdr(&mei_hdr, len);
551 
552 	memset(&prop_req, 0, sizeof(struct hbm_props_request));
553 
554 	prop_req.hbm_cmd = HOST_CLIENT_PROPERTIES_REQ_CMD;
555 	prop_req.me_addr = addr;
556 
557 	ret = mei_write_message(dev, &mei_hdr, &prop_req);
558 	if (ret) {
559 		dev_err(dev->dev, "properties request write failed: ret = %d\n",
560 			ret);
561 		return ret;
562 	}
563 
564 	dev->init_clients_timer = MEI_CLIENTS_INIT_TIMEOUT;
565 
566 	return 0;
567 }
568 
569 /**
570  * mei_hbm_pg - sends pg command
571  *
572  * @dev: the device structure
573  * @pg_cmd: the pg command code
574  *
575  * Return: -EIO on write failure
576  *         -EOPNOTSUPP if the operation is not supported by the protocol
577  */
578 int mei_hbm_pg(struct mei_device *dev, u8 pg_cmd)
579 {
580 	struct mei_msg_hdr mei_hdr;
581 	struct hbm_power_gate req;
582 	const size_t len = sizeof(struct hbm_power_gate);
583 	int ret;
584 
585 	if (!dev->hbm_f_pg_supported)
586 		return -EOPNOTSUPP;
587 
588 	mei_hbm_hdr(&mei_hdr, len);
589 
590 	memset(&req, 0, len);
591 	req.hbm_cmd = pg_cmd;
592 
593 	ret = mei_write_message(dev, &mei_hdr, &req);
594 	if (ret)
595 		dev_err(dev->dev, "power gate command write failed.\n");
596 	return ret;
597 }
598 EXPORT_SYMBOL_GPL(mei_hbm_pg);
599 
600 /**
601  * mei_hbm_stop_req - send stop request message
602  *
603  * @dev: mei device
604  *
605  * Return: -EIO on write failure
606  */
607 static int mei_hbm_stop_req(struct mei_device *dev)
608 {
609 	struct mei_msg_hdr mei_hdr;
610 	struct hbm_host_stop_request req;
611 	const size_t len = sizeof(struct hbm_host_stop_request);
612 
613 	mei_hbm_hdr(&mei_hdr, len);
614 
615 	memset(&req, 0, len);
616 	req.hbm_cmd = HOST_STOP_REQ_CMD;
617 	req.reason = DRIVER_STOP_REQUEST;
618 
619 	return mei_write_message(dev, &mei_hdr, &req);
620 }
621 
622 /**
623  * mei_hbm_cl_flow_control_req - sends flow control request.
624  *
625  * @dev: the device structure
626  * @cl: client info
627  *
628  * Return: -EIO on write failure
629  */
630 int mei_hbm_cl_flow_control_req(struct mei_device *dev, struct mei_cl *cl)
631 {
632 	const size_t len = sizeof(struct hbm_flow_control);
633 	u8 buf[len];
634 
635 	cl_dbg(dev, cl, "sending flow control\n");
636 	return mei_hbm_cl_write(dev, cl, MEI_FLOW_CONTROL_CMD, buf, len);
637 }
638 
639 /**
640  * mei_hbm_add_single_tx_flow_ctrl_creds - adds single buffer credentials.
641  *
642  * @dev: the device structure
643  * @fctrl: flow control response bus message
644  *
645  * Return: 0 on success, < 0 otherwise
646  */
647 static int mei_hbm_add_single_tx_flow_ctrl_creds(struct mei_device *dev,
648 						 struct hbm_flow_control *fctrl)
649 {
650 	struct mei_me_client *me_cl;
651 	int rets;
652 
653 	me_cl = mei_me_cl_by_id(dev, fctrl->me_addr);
654 	if (!me_cl) {
655 		dev_err(dev->dev, "no such me client %d\n", fctrl->me_addr);
656 		return -ENOENT;
657 	}
658 
659 	if (WARN_ON(me_cl->props.single_recv_buf == 0)) {
660 		rets = -EINVAL;
661 		goto out;
662 	}
663 
664 	me_cl->tx_flow_ctrl_creds++;
665 	dev_dbg(dev->dev, "recv flow ctrl msg ME %d (single) creds = %d.\n",
666 		fctrl->me_addr, me_cl->tx_flow_ctrl_creds);
667 
668 	rets = 0;
669 out:
670 	mei_me_cl_put(me_cl);
671 	return rets;
672 }
673 
674 /**
675  * mei_hbm_cl_flow_control_res - flow control response from me
676  *
677  * @dev: the device structure
678  * @fctrl: flow control response bus message
679  */
680 static void mei_hbm_cl_tx_flow_ctrl_creds_res(struct mei_device *dev,
681 					       struct hbm_flow_control *fctrl)
682 {
683 	struct mei_cl *cl;
684 
685 	if (!fctrl->host_addr) {
686 		/* single receive buffer */
687 		mei_hbm_add_single_tx_flow_ctrl_creds(dev, fctrl);
688 		return;
689 	}
690 
691 	cl = mei_hbm_cl_find_by_cmd(dev, fctrl);
692 	if (cl) {
693 		cl->tx_flow_ctrl_creds++;
694 		cl_dbg(dev, cl, "flow control creds = %d.\n",
695 				cl->tx_flow_ctrl_creds);
696 	}
697 }
698 
699 
700 /**
701  * mei_hbm_cl_disconnect_req - sends disconnect message to fw.
702  *
703  * @dev: the device structure
704  * @cl: a client to disconnect from
705  *
706  * Return: -EIO on write failure
707  */
708 int mei_hbm_cl_disconnect_req(struct mei_device *dev, struct mei_cl *cl)
709 {
710 	const size_t len = sizeof(struct hbm_client_connect_request);
711 	u8 buf[len];
712 
713 	return mei_hbm_cl_write(dev, cl, CLIENT_DISCONNECT_REQ_CMD, buf, len);
714 }
715 
716 /**
717  * mei_hbm_cl_disconnect_rsp - sends disconnect respose to the FW
718  *
719  * @dev: the device structure
720  * @cl: a client to disconnect from
721  *
722  * Return: -EIO on write failure
723  */
724 int mei_hbm_cl_disconnect_rsp(struct mei_device *dev, struct mei_cl *cl)
725 {
726 	const size_t len = sizeof(struct hbm_client_connect_response);
727 	u8 buf[len];
728 
729 	return mei_hbm_cl_write(dev, cl, CLIENT_DISCONNECT_RES_CMD, buf, len);
730 }
731 
732 /**
733  * mei_hbm_cl_disconnect_res - update the client state according
734  *       disconnect response
735  *
736  * @dev: the device structure
737  * @cl: mei host client
738  * @cmd: disconnect client response host bus message
739  */
740 static void mei_hbm_cl_disconnect_res(struct mei_device *dev, struct mei_cl *cl,
741 				      struct mei_hbm_cl_cmd *cmd)
742 {
743 	struct hbm_client_connect_response *rs =
744 		(struct hbm_client_connect_response *)cmd;
745 
746 	cl_dbg(dev, cl, "hbm: disconnect response status=%d\n", rs->status);
747 
748 	if (rs->status == MEI_CL_DISCONN_SUCCESS)
749 		cl->state = MEI_FILE_DISCONNECT_REPLY;
750 	cl->status = 0;
751 }
752 
753 /**
754  * mei_hbm_cl_connect_req - send connection request to specific me client
755  *
756  * @dev: the device structure
757  * @cl: a client to connect to
758  *
759  * Return: -EIO on write failure
760  */
761 int mei_hbm_cl_connect_req(struct mei_device *dev, struct mei_cl *cl)
762 {
763 	const size_t len = sizeof(struct hbm_client_connect_request);
764 	u8 buf[len];
765 
766 	return mei_hbm_cl_write(dev, cl, CLIENT_CONNECT_REQ_CMD, buf, len);
767 }
768 
769 /**
770  * mei_hbm_cl_connect_res - update the client state according
771  *        connection response
772  *
773  * @dev: the device structure
774  * @cl: mei host client
775  * @cmd: connect client response host bus message
776  */
777 static void mei_hbm_cl_connect_res(struct mei_device *dev, struct mei_cl *cl,
778 				   struct mei_hbm_cl_cmd *cmd)
779 {
780 	struct hbm_client_connect_response *rs =
781 		(struct hbm_client_connect_response *)cmd;
782 
783 	cl_dbg(dev, cl, "hbm: connect response status=%s\n",
784 			mei_cl_conn_status_str(rs->status));
785 
786 	if (rs->status == MEI_CL_CONN_SUCCESS)
787 		cl->state = MEI_FILE_CONNECTED;
788 	else {
789 		cl->state = MEI_FILE_DISCONNECT_REPLY;
790 		if (rs->status == MEI_CL_CONN_NOT_FOUND) {
791 			mei_me_cl_del(dev, cl->me_cl);
792 			if (dev->dev_state == MEI_DEV_ENABLED)
793 				schedule_work(&dev->bus_rescan_work);
794 		}
795 	}
796 	cl->status = mei_cl_conn_status_to_errno(rs->status);
797 }
798 
799 /**
800  * mei_hbm_cl_res - process hbm response received on behalf
801  *         an client
802  *
803  * @dev: the device structure
804  * @rs:  hbm client message
805  * @fop_type: file operation type
806  */
807 static void mei_hbm_cl_res(struct mei_device *dev,
808 			   struct mei_hbm_cl_cmd *rs,
809 			   enum mei_cb_file_ops fop_type)
810 {
811 	struct mei_cl *cl;
812 	struct mei_cl_cb *cb, *next;
813 
814 	cl = NULL;
815 	list_for_each_entry_safe(cb, next, &dev->ctrl_rd_list.list, list) {
816 
817 		cl = cb->cl;
818 
819 		if (cb->fop_type != fop_type)
820 			continue;
821 
822 		if (mei_hbm_cl_addr_equal(cl, rs)) {
823 			list_del_init(&cb->list);
824 			break;
825 		}
826 	}
827 
828 	if (!cl)
829 		return;
830 
831 	switch (fop_type) {
832 	case MEI_FOP_CONNECT:
833 		mei_hbm_cl_connect_res(dev, cl, rs);
834 		break;
835 	case MEI_FOP_DISCONNECT:
836 		mei_hbm_cl_disconnect_res(dev, cl, rs);
837 		break;
838 	case MEI_FOP_NOTIFY_START:
839 		mei_hbm_cl_notify_start_res(dev, cl, rs);
840 		break;
841 	case MEI_FOP_NOTIFY_STOP:
842 		mei_hbm_cl_notify_stop_res(dev, cl, rs);
843 		break;
844 	default:
845 		return;
846 	}
847 
848 	cl->timer_count = 0;
849 	wake_up(&cl->wait);
850 }
851 
852 
853 /**
854  * mei_hbm_fw_disconnect_req - disconnect request initiated by ME firmware
855  *  host sends disconnect response
856  *
857  * @dev: the device structure.
858  * @disconnect_req: disconnect request bus message from the me
859  *
860  * Return: -ENOMEM on allocation failure
861  */
862 static int mei_hbm_fw_disconnect_req(struct mei_device *dev,
863 		struct hbm_client_connect_request *disconnect_req)
864 {
865 	struct mei_cl *cl;
866 	struct mei_cl_cb *cb;
867 
868 	cl = mei_hbm_cl_find_by_cmd(dev, disconnect_req);
869 	if (cl) {
870 		cl_warn(dev, cl, "fw disconnect request received\n");
871 		cl->state = MEI_FILE_DISCONNECTING;
872 		cl->timer_count = 0;
873 
874 		cb = mei_cl_enqueue_ctrl_wr_cb(cl, 0, MEI_FOP_DISCONNECT_RSP,
875 					       NULL);
876 		if (!cb)
877 			return -ENOMEM;
878 	}
879 	return 0;
880 }
881 
882 /**
883  * mei_hbm_pg_enter_res - PG enter response received
884  *
885  * @dev: the device structure.
886  *
887  * Return: 0 on success, -EPROTO on state mismatch
888  */
889 static int mei_hbm_pg_enter_res(struct mei_device *dev)
890 {
891 	if (mei_pg_state(dev) != MEI_PG_OFF ||
892 	    dev->pg_event != MEI_PG_EVENT_WAIT) {
893 		dev_err(dev->dev, "hbm: pg entry response: state mismatch [%s, %d]\n",
894 			mei_pg_state_str(mei_pg_state(dev)), dev->pg_event);
895 		return -EPROTO;
896 	}
897 
898 	dev->pg_event = MEI_PG_EVENT_RECEIVED;
899 	wake_up(&dev->wait_pg);
900 
901 	return 0;
902 }
903 
904 /**
905  * mei_hbm_pg_resume - process with PG resume
906  *
907  * @dev: the device structure.
908  */
909 void mei_hbm_pg_resume(struct mei_device *dev)
910 {
911 	pm_request_resume(dev->dev);
912 }
913 EXPORT_SYMBOL_GPL(mei_hbm_pg_resume);
914 
915 /**
916  * mei_hbm_pg_exit_res - PG exit response received
917  *
918  * @dev: the device structure.
919  *
920  * Return: 0 on success, -EPROTO on state mismatch
921  */
922 static int mei_hbm_pg_exit_res(struct mei_device *dev)
923 {
924 	if (mei_pg_state(dev) != MEI_PG_ON ||
925 	    (dev->pg_event != MEI_PG_EVENT_WAIT &&
926 	     dev->pg_event != MEI_PG_EVENT_IDLE)) {
927 		dev_err(dev->dev, "hbm: pg exit response: state mismatch [%s, %d]\n",
928 			mei_pg_state_str(mei_pg_state(dev)), dev->pg_event);
929 		return -EPROTO;
930 	}
931 
932 	switch (dev->pg_event) {
933 	case MEI_PG_EVENT_WAIT:
934 		dev->pg_event = MEI_PG_EVENT_RECEIVED;
935 		wake_up(&dev->wait_pg);
936 		break;
937 	case MEI_PG_EVENT_IDLE:
938 		/*
939 		* If the driver is not waiting on this then
940 		* this is HW initiated exit from PG.
941 		* Start runtime pm resume sequence to exit from PG.
942 		*/
943 		dev->pg_event = MEI_PG_EVENT_RECEIVED;
944 		mei_hbm_pg_resume(dev);
945 		break;
946 	default:
947 		WARN(1, "hbm: pg exit response: unexpected pg event = %d\n",
948 		     dev->pg_event);
949 		return -EPROTO;
950 	}
951 
952 	return 0;
953 }
954 
955 /**
956  * mei_hbm_config_features - check what hbm features and commands
957  *        are supported by the fw
958  *
959  * @dev: the device structure
960  */
961 static void mei_hbm_config_features(struct mei_device *dev)
962 {
963 	/* Power Gating Isolation Support */
964 	dev->hbm_f_pg_supported = 0;
965 	if (dev->version.major_version > HBM_MAJOR_VERSION_PGI)
966 		dev->hbm_f_pg_supported = 1;
967 
968 	if (dev->version.major_version == HBM_MAJOR_VERSION_PGI &&
969 	    dev->version.minor_version >= HBM_MINOR_VERSION_PGI)
970 		dev->hbm_f_pg_supported = 1;
971 
972 	if (dev->version.major_version >= HBM_MAJOR_VERSION_DC)
973 		dev->hbm_f_dc_supported = 1;
974 
975 	if (dev->version.major_version >= HBM_MAJOR_VERSION_IE)
976 		dev->hbm_f_ie_supported = 1;
977 
978 	/* disconnect on connect timeout instead of link reset */
979 	if (dev->version.major_version >= HBM_MAJOR_VERSION_DOT)
980 		dev->hbm_f_dot_supported = 1;
981 
982 	/* Notification Event Support */
983 	if (dev->version.major_version >= HBM_MAJOR_VERSION_EV)
984 		dev->hbm_f_ev_supported = 1;
985 
986 	/* Fixed Address Client Support */
987 	if (dev->version.major_version >= HBM_MAJOR_VERSION_FA)
988 		dev->hbm_f_fa_supported = 1;
989 }
990 
991 /**
992  * mei_hbm_version_is_supported - checks whether the driver can
993  *     support the hbm version of the device
994  *
995  * @dev: the device structure
996  * Return: true if driver can support hbm version of the device
997  */
998 bool mei_hbm_version_is_supported(struct mei_device *dev)
999 {
1000 	return	(dev->version.major_version < HBM_MAJOR_VERSION) ||
1001 		(dev->version.major_version == HBM_MAJOR_VERSION &&
1002 		 dev->version.minor_version <= HBM_MINOR_VERSION);
1003 }
1004 
1005 /**
1006  * mei_hbm_dispatch - bottom half read routine after ISR to
1007  * handle the read bus message cmd processing.
1008  *
1009  * @dev: the device structure
1010  * @hdr: header of bus message
1011  *
1012  * Return: 0 on success and < 0 on failure
1013  */
1014 int mei_hbm_dispatch(struct mei_device *dev, struct mei_msg_hdr *hdr)
1015 {
1016 	struct mei_bus_message *mei_msg;
1017 	struct hbm_host_version_response *version_res;
1018 	struct hbm_props_response *props_res;
1019 	struct hbm_host_enum_response *enum_res;
1020 	struct hbm_add_client_request *add_cl_req;
1021 	int ret;
1022 
1023 	struct mei_hbm_cl_cmd *cl_cmd;
1024 	struct hbm_client_connect_request *disconnect_req;
1025 	struct hbm_flow_control *fctrl;
1026 
1027 	/* read the message to our buffer */
1028 	BUG_ON(hdr->length >= sizeof(dev->rd_msg_buf));
1029 	mei_read_slots(dev, dev->rd_msg_buf, hdr->length);
1030 	mei_msg = (struct mei_bus_message *)dev->rd_msg_buf;
1031 	cl_cmd  = (struct mei_hbm_cl_cmd *)mei_msg;
1032 
1033 	/* ignore spurious message and prevent reset nesting
1034 	 * hbm is put to idle during system reset
1035 	 */
1036 	if (dev->hbm_state == MEI_HBM_IDLE) {
1037 		dev_dbg(dev->dev, "hbm: state is idle ignore spurious messages\n");
1038 		return 0;
1039 	}
1040 
1041 	switch (mei_msg->hbm_cmd) {
1042 	case HOST_START_RES_CMD:
1043 		dev_dbg(dev->dev, "hbm: start: response message received.\n");
1044 
1045 		dev->init_clients_timer = 0;
1046 
1047 		version_res = (struct hbm_host_version_response *)mei_msg;
1048 
1049 		dev_dbg(dev->dev, "HBM VERSION: DRIVER=%02d:%02d DEVICE=%02d:%02d\n",
1050 				HBM_MAJOR_VERSION, HBM_MINOR_VERSION,
1051 				version_res->me_max_version.major_version,
1052 				version_res->me_max_version.minor_version);
1053 
1054 		if (version_res->host_version_supported) {
1055 			dev->version.major_version = HBM_MAJOR_VERSION;
1056 			dev->version.minor_version = HBM_MINOR_VERSION;
1057 		} else {
1058 			dev->version.major_version =
1059 				version_res->me_max_version.major_version;
1060 			dev->version.minor_version =
1061 				version_res->me_max_version.minor_version;
1062 		}
1063 
1064 		if (!mei_hbm_version_is_supported(dev)) {
1065 			dev_warn(dev->dev, "hbm: start: version mismatch - stopping the driver.\n");
1066 
1067 			dev->hbm_state = MEI_HBM_STOPPED;
1068 			if (mei_hbm_stop_req(dev)) {
1069 				dev_err(dev->dev, "hbm: start: failed to send stop request\n");
1070 				return -EIO;
1071 			}
1072 			break;
1073 		}
1074 
1075 		mei_hbm_config_features(dev);
1076 
1077 		if (dev->dev_state != MEI_DEV_INIT_CLIENTS ||
1078 		    dev->hbm_state != MEI_HBM_STARTING) {
1079 			dev_err(dev->dev, "hbm: start: state mismatch, [%d, %d]\n",
1080 				dev->dev_state, dev->hbm_state);
1081 			return -EPROTO;
1082 		}
1083 
1084 		if (mei_hbm_enum_clients_req(dev)) {
1085 			dev_err(dev->dev, "hbm: start: failed to send enumeration request\n");
1086 			return -EIO;
1087 		}
1088 
1089 		wake_up(&dev->wait_hbm_start);
1090 		break;
1091 
1092 	case CLIENT_CONNECT_RES_CMD:
1093 		dev_dbg(dev->dev, "hbm: client connect response: message received.\n");
1094 		mei_hbm_cl_res(dev, cl_cmd, MEI_FOP_CONNECT);
1095 		break;
1096 
1097 	case CLIENT_DISCONNECT_RES_CMD:
1098 		dev_dbg(dev->dev, "hbm: client disconnect response: message received.\n");
1099 		mei_hbm_cl_res(dev, cl_cmd, MEI_FOP_DISCONNECT);
1100 		break;
1101 
1102 	case MEI_FLOW_CONTROL_CMD:
1103 		dev_dbg(dev->dev, "hbm: client flow control response: message received.\n");
1104 
1105 		fctrl = (struct hbm_flow_control *)mei_msg;
1106 		mei_hbm_cl_tx_flow_ctrl_creds_res(dev, fctrl);
1107 		break;
1108 
1109 	case MEI_PG_ISOLATION_ENTRY_RES_CMD:
1110 		dev_dbg(dev->dev, "hbm: power gate isolation entry response received\n");
1111 		ret = mei_hbm_pg_enter_res(dev);
1112 		if (ret)
1113 			return ret;
1114 		break;
1115 
1116 	case MEI_PG_ISOLATION_EXIT_REQ_CMD:
1117 		dev_dbg(dev->dev, "hbm: power gate isolation exit request received\n");
1118 		ret = mei_hbm_pg_exit_res(dev);
1119 		if (ret)
1120 			return ret;
1121 		break;
1122 
1123 	case HOST_CLIENT_PROPERTIES_RES_CMD:
1124 		dev_dbg(dev->dev, "hbm: properties response: message received.\n");
1125 
1126 		dev->init_clients_timer = 0;
1127 
1128 		if (dev->dev_state != MEI_DEV_INIT_CLIENTS ||
1129 		    dev->hbm_state != MEI_HBM_CLIENT_PROPERTIES) {
1130 			dev_err(dev->dev, "hbm: properties response: state mismatch, [%d, %d]\n",
1131 				dev->dev_state, dev->hbm_state);
1132 			return -EPROTO;
1133 		}
1134 
1135 		props_res = (struct hbm_props_response *)mei_msg;
1136 
1137 		if (props_res->status) {
1138 			dev_err(dev->dev, "hbm: properties response: wrong status = %d %s\n",
1139 				props_res->status,
1140 				mei_hbm_status_str(props_res->status));
1141 			return -EPROTO;
1142 		}
1143 
1144 		mei_hbm_me_cl_add(dev, props_res);
1145 
1146 		/* request property for the next client */
1147 		if (mei_hbm_prop_req(dev, props_res->me_addr + 1))
1148 			return -EIO;
1149 
1150 		break;
1151 
1152 	case HOST_ENUM_RES_CMD:
1153 		dev_dbg(dev->dev, "hbm: enumeration response: message received\n");
1154 
1155 		dev->init_clients_timer = 0;
1156 
1157 		enum_res = (struct hbm_host_enum_response *) mei_msg;
1158 		BUILD_BUG_ON(sizeof(dev->me_clients_map)
1159 				< sizeof(enum_res->valid_addresses));
1160 		memcpy(dev->me_clients_map, enum_res->valid_addresses,
1161 				sizeof(enum_res->valid_addresses));
1162 
1163 		if (dev->dev_state != MEI_DEV_INIT_CLIENTS ||
1164 		    dev->hbm_state != MEI_HBM_ENUM_CLIENTS) {
1165 			dev_err(dev->dev, "hbm: enumeration response: state mismatch, [%d, %d]\n",
1166 				dev->dev_state, dev->hbm_state);
1167 			return -EPROTO;
1168 		}
1169 
1170 		dev->hbm_state = MEI_HBM_CLIENT_PROPERTIES;
1171 
1172 		/* first property request */
1173 		if (mei_hbm_prop_req(dev, 0))
1174 			return -EIO;
1175 
1176 		break;
1177 
1178 	case HOST_STOP_RES_CMD:
1179 		dev_dbg(dev->dev, "hbm: stop response: message received\n");
1180 
1181 		dev->init_clients_timer = 0;
1182 
1183 		if (dev->hbm_state != MEI_HBM_STOPPED) {
1184 			dev_err(dev->dev, "hbm: stop response: state mismatch, [%d, %d]\n",
1185 				dev->dev_state, dev->hbm_state);
1186 			return -EPROTO;
1187 		}
1188 
1189 		dev->dev_state = MEI_DEV_POWER_DOWN;
1190 		dev_info(dev->dev, "hbm: stop response: resetting.\n");
1191 		/* force the reset */
1192 		return -EPROTO;
1193 		break;
1194 
1195 	case CLIENT_DISCONNECT_REQ_CMD:
1196 		dev_dbg(dev->dev, "hbm: disconnect request: message received\n");
1197 
1198 		disconnect_req = (struct hbm_client_connect_request *)mei_msg;
1199 		mei_hbm_fw_disconnect_req(dev, disconnect_req);
1200 		break;
1201 
1202 	case ME_STOP_REQ_CMD:
1203 		dev_dbg(dev->dev, "hbm: stop request: message received\n");
1204 		dev->hbm_state = MEI_HBM_STOPPED;
1205 		if (mei_hbm_stop_req(dev)) {
1206 			dev_err(dev->dev, "hbm: stop request: failed to send stop request\n");
1207 			return -EIO;
1208 		}
1209 		break;
1210 
1211 	case MEI_HBM_ADD_CLIENT_REQ_CMD:
1212 		dev_dbg(dev->dev, "hbm: add client request received\n");
1213 		/*
1214 		 * after the host receives the enum_resp
1215 		 * message clients may be added or removed
1216 		 */
1217 		if (dev->hbm_state <= MEI_HBM_ENUM_CLIENTS ||
1218 		    dev->hbm_state >= MEI_HBM_STOPPED) {
1219 			dev_err(dev->dev, "hbm: add client: state mismatch, [%d, %d]\n",
1220 				dev->dev_state, dev->hbm_state);
1221 			return -EPROTO;
1222 		}
1223 		add_cl_req = (struct hbm_add_client_request *)mei_msg;
1224 		ret = mei_hbm_fw_add_cl_req(dev, add_cl_req);
1225 		if (ret) {
1226 			dev_err(dev->dev, "hbm: add client: failed to send response %d\n",
1227 				ret);
1228 			return -EIO;
1229 		}
1230 		dev_dbg(dev->dev, "hbm: add client request processed\n");
1231 		break;
1232 
1233 	case MEI_HBM_NOTIFY_RES_CMD:
1234 		dev_dbg(dev->dev, "hbm: notify response received\n");
1235 		mei_hbm_cl_res(dev, cl_cmd, notify_res_to_fop(cl_cmd));
1236 		break;
1237 
1238 	case MEI_HBM_NOTIFICATION_CMD:
1239 		dev_dbg(dev->dev, "hbm: notification\n");
1240 		mei_hbm_cl_notify(dev, cl_cmd);
1241 		break;
1242 
1243 	default:
1244 		BUG();
1245 		break;
1246 
1247 	}
1248 	return 0;
1249 }
1250 
1251