xref: /openbmc/linux/drivers/misc/mei/hbm.c (revision 9cfc5c90)
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 	dev->me_client_index = 0;
117 
118 	mei_me_cl_rm_all(dev);
119 
120 	mei_hbm_idle(dev);
121 }
122 
123 /**
124  * mei_hbm_hdr - construct hbm header
125  *
126  * @hdr: hbm header
127  * @length: payload length
128  */
129 
130 static inline void mei_hbm_hdr(struct mei_msg_hdr *hdr, size_t length)
131 {
132 	hdr->host_addr = 0;
133 	hdr->me_addr = 0;
134 	hdr->length = length;
135 	hdr->msg_complete = 1;
136 	hdr->reserved = 0;
137 }
138 
139 /**
140  * mei_hbm_cl_hdr - construct client hbm header
141  *
142  * @cl: client
143  * @hbm_cmd: host bus message command
144  * @buf: buffer for cl header
145  * @len: buffer length
146  */
147 static inline
148 void mei_hbm_cl_hdr(struct mei_cl *cl, u8 hbm_cmd, void *buf, size_t len)
149 {
150 	struct mei_hbm_cl_cmd *cmd = buf;
151 
152 	memset(cmd, 0, len);
153 
154 	cmd->hbm_cmd = hbm_cmd;
155 	cmd->host_addr = mei_cl_host_addr(cl);
156 	cmd->me_addr = mei_cl_me_id(cl);
157 }
158 
159 /**
160  * mei_hbm_cl_write - write simple hbm client message
161  *
162  * @dev: the device structure
163  * @cl: client
164  * @hbm_cmd: host bus message command
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,
171 		     struct mei_cl *cl, u8 hbm_cmd, size_t len)
172 {
173 	struct mei_msg_hdr *mei_hdr = &dev->wr_msg.hdr;
174 
175 	mei_hbm_hdr(mei_hdr, len);
176 	mei_hbm_cl_hdr(cl, hbm_cmd, dev->wr_msg.data, len);
177 
178 	return mei_write_message(dev, mei_hdr, dev->wr_msg.data);
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 = &dev->wr_msg.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 	start_req = (struct hbm_host_version_request *)dev->wr_msg.data;
266 	memset(start_req, 0, len);
267 	start_req->hbm_cmd = HOST_START_REQ_CMD;
268 	start_req->host_version.major_version = HBM_MAJOR_VERSION;
269 	start_req->host_version.minor_version = HBM_MINOR_VERSION;
270 
271 	dev->hbm_state = MEI_HBM_IDLE;
272 	ret = mei_write_message(dev, mei_hdr, dev->wr_msg.data);
273 	if (ret) {
274 		dev_err(dev->dev, "version message write failed: ret = %d\n",
275 			ret);
276 		return ret;
277 	}
278 
279 	dev->hbm_state = MEI_HBM_STARTING;
280 	dev->init_clients_timer = MEI_CLIENTS_INIT_TIMEOUT;
281 	return 0;
282 }
283 
284 /**
285  * mei_hbm_enum_clients_req - sends enumeration client request message.
286  *
287  * @dev: the device structure
288  *
289  * Return: 0 on success and < 0 on failure
290  */
291 static int mei_hbm_enum_clients_req(struct mei_device *dev)
292 {
293 	struct mei_msg_hdr *mei_hdr = &dev->wr_msg.hdr;
294 	struct hbm_host_enum_request *enum_req;
295 	const size_t len = sizeof(struct hbm_host_enum_request);
296 	int ret;
297 
298 	/* enumerate clients */
299 	mei_hbm_hdr(mei_hdr, len);
300 
301 	enum_req = (struct hbm_host_enum_request *)dev->wr_msg.data;
302 	memset(enum_req, 0, len);
303 	enum_req->hbm_cmd = HOST_ENUM_REQ_CMD;
304 	enum_req->allow_add = dev->hbm_f_dc_supported;
305 
306 	ret = mei_write_message(dev, mei_hdr, dev->wr_msg.data);
307 	if (ret) {
308 		dev_err(dev->dev, "enumeration request write failed: ret = %d.\n",
309 			ret);
310 		return ret;
311 	}
312 	dev->hbm_state = MEI_HBM_ENUM_CLIENTS;
313 	dev->init_clients_timer = MEI_CLIENTS_INIT_TIMEOUT;
314 	return 0;
315 }
316 
317 /**
318  * mei_hbm_me_cl_add - add new me client to the list
319  *
320  * @dev: the device structure
321  * @res: hbm property response
322  *
323  * Return: 0 on success and -ENOMEM on allocation failure
324  */
325 
326 static int mei_hbm_me_cl_add(struct mei_device *dev,
327 			     struct hbm_props_response *res)
328 {
329 	struct mei_me_client *me_cl;
330 	const uuid_le *uuid = &res->client_properties.protocol_name;
331 
332 	mei_me_cl_rm_by_uuid(dev, uuid);
333 
334 	me_cl = kzalloc(sizeof(struct mei_me_client), GFP_KERNEL);
335 	if (!me_cl)
336 		return -ENOMEM;
337 
338 	mei_me_cl_init(me_cl);
339 
340 	me_cl->props = res->client_properties;
341 	me_cl->client_id = res->me_addr;
342 	me_cl->mei_flow_ctrl_creds = 0;
343 
344 	mei_me_cl_add(dev, me_cl);
345 
346 	return 0;
347 }
348 
349 /**
350  * mei_hbm_add_cl_resp - send response to fw on client add request
351  *
352  * @dev: the device structure
353  * @addr: me address
354  * @status: response status
355  *
356  * Return: 0 on success and < 0 on failure
357  */
358 static int mei_hbm_add_cl_resp(struct mei_device *dev, u8 addr, u8 status)
359 {
360 	struct mei_msg_hdr *mei_hdr = &dev->wr_msg.hdr;
361 	struct hbm_add_client_response *resp;
362 	const size_t len = sizeof(struct hbm_add_client_response);
363 	int ret;
364 
365 	dev_dbg(dev->dev, "adding client response\n");
366 
367 	resp = (struct hbm_add_client_response *)dev->wr_msg.data;
368 
369 	mei_hbm_hdr(mei_hdr, len);
370 	memset(resp, 0, sizeof(struct hbm_add_client_response));
371 
372 	resp->hbm_cmd = MEI_HBM_ADD_CLIENT_RES_CMD;
373 	resp->me_addr = addr;
374 	resp->status  = status;
375 
376 	ret = mei_write_message(dev, mei_hdr, dev->wr_msg.data);
377 	if (ret)
378 		dev_err(dev->dev, "add client response write failed: ret = %d\n",
379 			ret);
380 	return ret;
381 }
382 
383 /**
384  * mei_hbm_fw_add_cl_req - request from the fw to add a client
385  *
386  * @dev: the device structure
387  * @req: add client request
388  *
389  * Return: 0 on success and < 0 on failure
390  */
391 static int mei_hbm_fw_add_cl_req(struct mei_device *dev,
392 			      struct hbm_add_client_request *req)
393 {
394 	int ret;
395 	u8 status = MEI_HBMS_SUCCESS;
396 
397 	BUILD_BUG_ON(sizeof(struct hbm_add_client_request) !=
398 			sizeof(struct hbm_props_response));
399 
400 	ret = mei_hbm_me_cl_add(dev, (struct hbm_props_response *)req);
401 	if (ret)
402 		status = !MEI_HBMS_SUCCESS;
403 
404 	return mei_hbm_add_cl_resp(dev, req->me_addr, status);
405 }
406 
407 /**
408  * mei_hbm_cl_notify_req - send notification request
409  *
410  * @dev: the device structure
411  * @cl: a client to disconnect from
412  * @start: true for start false for stop
413  *
414  * Return: 0 on success and -EIO on write failure
415  */
416 int mei_hbm_cl_notify_req(struct mei_device *dev,
417 			  struct mei_cl *cl, u8 start)
418 {
419 
420 	struct mei_msg_hdr *mei_hdr = &dev->wr_msg.hdr;
421 	struct hbm_notification_request *req;
422 	const size_t len = sizeof(struct hbm_notification_request);
423 	int ret;
424 
425 	mei_hbm_hdr(mei_hdr, len);
426 	mei_hbm_cl_hdr(cl, MEI_HBM_NOTIFY_REQ_CMD, dev->wr_msg.data, len);
427 
428 	req = (struct hbm_notification_request *)dev->wr_msg.data;
429 	req->start = start;
430 
431 	ret = mei_write_message(dev, mei_hdr, dev->wr_msg.data);
432 	if (ret)
433 		dev_err(dev->dev, "notify request failed: ret = %d\n", ret);
434 
435 	return ret;
436 }
437 
438 /**
439  *  notify_res_to_fop - convert notification response to the proper
440  *      notification FOP
441  *
442  * @cmd: client notification start response command
443  *
444  * Return:  MEI_FOP_NOTIFY_START or MEI_FOP_NOTIFY_STOP;
445  */
446 static inline enum mei_cb_file_ops notify_res_to_fop(struct mei_hbm_cl_cmd *cmd)
447 {
448 	struct hbm_notification_response *rs =
449 		(struct hbm_notification_response *)cmd;
450 
451 	return mei_cl_notify_req2fop(rs->start);
452 }
453 
454 /**
455  * mei_hbm_cl_notify_start_res - update the client state according
456  *       notify start response
457  *
458  * @dev: the device structure
459  * @cl: mei host client
460  * @cmd: client notification start response command
461  */
462 static void mei_hbm_cl_notify_start_res(struct mei_device *dev,
463 					struct mei_cl *cl,
464 					struct mei_hbm_cl_cmd *cmd)
465 {
466 	struct hbm_notification_response *rs =
467 		(struct hbm_notification_response *)cmd;
468 
469 	cl_dbg(dev, cl, "hbm: notify start response status=%d\n", rs->status);
470 
471 	if (rs->status == MEI_HBMS_SUCCESS ||
472 	    rs->status == MEI_HBMS_ALREADY_STARTED) {
473 		cl->notify_en = true;
474 		cl->status = 0;
475 	} else {
476 		cl->status = -EINVAL;
477 	}
478 }
479 
480 /**
481  * mei_hbm_cl_notify_stop_res - update the client state according
482  *       notify stop response
483  *
484  * @dev: the device structure
485  * @cl: mei host client
486  * @cmd: client notification stop response command
487  */
488 static void mei_hbm_cl_notify_stop_res(struct mei_device *dev,
489 				       struct mei_cl *cl,
490 				       struct mei_hbm_cl_cmd *cmd)
491 {
492 	struct hbm_notification_response *rs =
493 		(struct hbm_notification_response *)cmd;
494 
495 	cl_dbg(dev, cl, "hbm: notify stop response status=%d\n", rs->status);
496 
497 	if (rs->status == MEI_HBMS_SUCCESS ||
498 	    rs->status == MEI_HBMS_NOT_STARTED) {
499 		cl->notify_en = false;
500 		cl->status = 0;
501 	} else {
502 		/* TODO: spec is not clear yet about other possible issues */
503 		cl->status = -EINVAL;
504 	}
505 }
506 
507 /**
508  * mei_hbm_cl_notify - signal notification event
509  *
510  * @dev: the device structure
511  * @cmd: notification client message
512  */
513 static void mei_hbm_cl_notify(struct mei_device *dev,
514 			      struct mei_hbm_cl_cmd *cmd)
515 {
516 	struct mei_cl *cl;
517 
518 	cl = mei_hbm_cl_find_by_cmd(dev, cmd);
519 	if (cl)
520 		mei_cl_notify(cl);
521 }
522 
523 /**
524  * mei_hbm_prop_req - request property for a single client
525  *
526  * @dev: the device structure
527  *
528  * Return: 0 on success and < 0 on failure
529  */
530 
531 static int mei_hbm_prop_req(struct mei_device *dev)
532 {
533 
534 	struct mei_msg_hdr *mei_hdr = &dev->wr_msg.hdr;
535 	struct hbm_props_request *prop_req;
536 	const size_t len = sizeof(struct hbm_props_request);
537 	unsigned long next_client_index;
538 	int ret;
539 
540 	next_client_index = find_next_bit(dev->me_clients_map, MEI_CLIENTS_MAX,
541 					  dev->me_client_index);
542 
543 	/* We got all client properties */
544 	if (next_client_index == MEI_CLIENTS_MAX) {
545 		dev->hbm_state = MEI_HBM_STARTED;
546 		schedule_work(&dev->init_work);
547 
548 		return 0;
549 	}
550 
551 	mei_hbm_hdr(mei_hdr, len);
552 	prop_req = (struct hbm_props_request *)dev->wr_msg.data;
553 
554 	memset(prop_req, 0, sizeof(struct hbm_props_request));
555 
556 	prop_req->hbm_cmd = HOST_CLIENT_PROPERTIES_REQ_CMD;
557 	prop_req->me_addr = next_client_index;
558 
559 	ret = mei_write_message(dev, mei_hdr, dev->wr_msg.data);
560 	if (ret) {
561 		dev_err(dev->dev, "properties request write failed: ret = %d\n",
562 			ret);
563 		return ret;
564 	}
565 
566 	dev->init_clients_timer = MEI_CLIENTS_INIT_TIMEOUT;
567 	dev->me_client_index = next_client_index;
568 
569 	return 0;
570 }
571 
572 /**
573  * mei_hbm_pg - sends pg command
574  *
575  * @dev: the device structure
576  * @pg_cmd: the pg command code
577  *
578  * Return: -EIO on write failure
579  *         -EOPNOTSUPP if the operation is not supported by the protocol
580  */
581 int mei_hbm_pg(struct mei_device *dev, u8 pg_cmd)
582 {
583 	struct mei_msg_hdr *mei_hdr = &dev->wr_msg.hdr;
584 	struct hbm_power_gate *req;
585 	const size_t len = sizeof(struct hbm_power_gate);
586 	int ret;
587 
588 	if (!dev->hbm_f_pg_supported)
589 		return -EOPNOTSUPP;
590 
591 	mei_hbm_hdr(mei_hdr, len);
592 
593 	req = (struct hbm_power_gate *)dev->wr_msg.data;
594 	memset(req, 0, len);
595 	req->hbm_cmd = pg_cmd;
596 
597 	ret = mei_write_message(dev, mei_hdr, dev->wr_msg.data);
598 	if (ret)
599 		dev_err(dev->dev, "power gate command write failed.\n");
600 	return ret;
601 }
602 EXPORT_SYMBOL_GPL(mei_hbm_pg);
603 
604 /**
605  * mei_hbm_stop_req - send stop request message
606  *
607  * @dev: mei device
608  *
609  * Return: -EIO on write failure
610  */
611 static int mei_hbm_stop_req(struct mei_device *dev)
612 {
613 	struct mei_msg_hdr *mei_hdr = &dev->wr_msg.hdr;
614 	struct hbm_host_stop_request *req =
615 			(struct hbm_host_stop_request *)dev->wr_msg.data;
616 	const size_t len = sizeof(struct hbm_host_stop_request);
617 
618 	mei_hbm_hdr(mei_hdr, len);
619 
620 	memset(req, 0, len);
621 	req->hbm_cmd = HOST_STOP_REQ_CMD;
622 	req->reason = DRIVER_STOP_REQUEST;
623 
624 	return mei_write_message(dev, mei_hdr, dev->wr_msg.data);
625 }
626 
627 /**
628  * mei_hbm_cl_flow_control_req - sends flow control request.
629  *
630  * @dev: the device structure
631  * @cl: client info
632  *
633  * Return: -EIO on write failure
634  */
635 int mei_hbm_cl_flow_control_req(struct mei_device *dev, struct mei_cl *cl)
636 {
637 	const size_t len = sizeof(struct hbm_flow_control);
638 
639 	cl_dbg(dev, cl, "sending flow control\n");
640 	return mei_hbm_cl_write(dev, cl, MEI_FLOW_CONTROL_CMD, len);
641 }
642 
643 /**
644  * mei_hbm_add_single_flow_creds - adds single buffer credentials.
645  *
646  * @dev: the device structure
647  * @flow: flow control.
648  *
649  * Return: 0 on success, < 0 otherwise
650  */
651 static int mei_hbm_add_single_flow_creds(struct mei_device *dev,
652 				  struct hbm_flow_control *flow)
653 {
654 	struct mei_me_client *me_cl;
655 	int rets;
656 
657 	me_cl = mei_me_cl_by_id(dev, flow->me_addr);
658 	if (!me_cl) {
659 		dev_err(dev->dev, "no such me client %d\n",
660 			flow->me_addr);
661 		return -ENOENT;
662 	}
663 
664 	if (WARN_ON(me_cl->props.single_recv_buf == 0)) {
665 		rets = -EINVAL;
666 		goto out;
667 	}
668 
669 	me_cl->mei_flow_ctrl_creds++;
670 	dev_dbg(dev->dev, "recv flow ctrl msg ME %d (single) creds = %d.\n",
671 	    flow->me_addr, me_cl->mei_flow_ctrl_creds);
672 
673 	rets = 0;
674 out:
675 	mei_me_cl_put(me_cl);
676 	return rets;
677 }
678 
679 /**
680  * mei_hbm_cl_flow_control_res - flow control response from me
681  *
682  * @dev: the device structure
683  * @flow_control: flow control response bus message
684  */
685 static void mei_hbm_cl_flow_control_res(struct mei_device *dev,
686 					struct hbm_flow_control *flow_control)
687 {
688 	struct mei_cl *cl;
689 
690 	if (!flow_control->host_addr) {
691 		/* single receive buffer */
692 		mei_hbm_add_single_flow_creds(dev, flow_control);
693 		return;
694 	}
695 
696 	cl = mei_hbm_cl_find_by_cmd(dev, flow_control);
697 	if (cl) {
698 		cl->mei_flow_ctrl_creds++;
699 		cl_dbg(dev, cl, "flow control creds = %d.\n",
700 				cl->mei_flow_ctrl_creds);
701 	}
702 }
703 
704 
705 /**
706  * mei_hbm_cl_disconnect_req - sends disconnect message to fw.
707  *
708  * @dev: the device structure
709  * @cl: a client to disconnect from
710  *
711  * Return: -EIO on write failure
712  */
713 int mei_hbm_cl_disconnect_req(struct mei_device *dev, struct mei_cl *cl)
714 {
715 	const size_t len = sizeof(struct hbm_client_connect_request);
716 
717 	return mei_hbm_cl_write(dev, cl, CLIENT_DISCONNECT_REQ_CMD, len);
718 }
719 
720 /**
721  * mei_hbm_cl_disconnect_rsp - sends disconnect respose to the FW
722  *
723  * @dev: the device structure
724  * @cl: a client to disconnect from
725  *
726  * Return: -EIO on write failure
727  */
728 int mei_hbm_cl_disconnect_rsp(struct mei_device *dev, struct mei_cl *cl)
729 {
730 	const size_t len = sizeof(struct hbm_client_connect_response);
731 
732 	return mei_hbm_cl_write(dev, cl, CLIENT_DISCONNECT_RES_CMD, len);
733 }
734 
735 /**
736  * mei_hbm_cl_disconnect_res - update the client state according
737  *       disconnect response
738  *
739  * @dev: the device structure
740  * @cl: mei host client
741  * @cmd: disconnect client response host bus message
742  */
743 static void mei_hbm_cl_disconnect_res(struct mei_device *dev, struct mei_cl *cl,
744 				      struct mei_hbm_cl_cmd *cmd)
745 {
746 	struct hbm_client_connect_response *rs =
747 		(struct hbm_client_connect_response *)cmd;
748 
749 	cl_dbg(dev, cl, "hbm: disconnect response status=%d\n", rs->status);
750 
751 	if (rs->status == MEI_CL_DISCONN_SUCCESS)
752 		cl->state = MEI_FILE_DISCONNECT_REPLY;
753 	cl->status = 0;
754 }
755 
756 /**
757  * mei_hbm_cl_connect_req - send connection request to specific me client
758  *
759  * @dev: the device structure
760  * @cl: a client to connect to
761  *
762  * Return: -EIO on write failure
763  */
764 int mei_hbm_cl_connect_req(struct mei_device *dev, struct mei_cl *cl)
765 {
766 	const size_t len = sizeof(struct hbm_client_connect_request);
767 
768 	return mei_hbm_cl_write(dev, cl, CLIENT_CONNECT_REQ_CMD, len);
769 }
770 
771 /**
772  * mei_hbm_cl_connect_res - update the client state according
773  *        connection response
774  *
775  * @dev: the device structure
776  * @cl: mei host client
777  * @cmd: connect client response host bus message
778  */
779 static void mei_hbm_cl_connect_res(struct mei_device *dev, struct mei_cl *cl,
780 				   struct mei_hbm_cl_cmd *cmd)
781 {
782 	struct hbm_client_connect_response *rs =
783 		(struct hbm_client_connect_response *)cmd;
784 
785 	cl_dbg(dev, cl, "hbm: connect response status=%s\n",
786 			mei_cl_conn_status_str(rs->status));
787 
788 	if (rs->status == MEI_CL_CONN_SUCCESS)
789 		cl->state = MEI_FILE_CONNECTED;
790 	else {
791 		cl->state = MEI_FILE_DISCONNECT_REPLY;
792 		if (rs->status == MEI_CL_CONN_NOT_FOUND)
793 			mei_me_cl_del(dev, cl->me_cl);
794 	}
795 	cl->status = mei_cl_conn_status_to_errno(rs->status);
796 }
797 
798 /**
799  * mei_hbm_cl_res - process hbm response received on behalf
800  *         an client
801  *
802  * @dev: the device structure
803  * @rs:  hbm client message
804  * @fop_type: file operation type
805  */
806 static void mei_hbm_cl_res(struct mei_device *dev,
807 			   struct mei_hbm_cl_cmd *rs,
808 			   enum mei_cb_file_ops fop_type)
809 {
810 	struct mei_cl *cl;
811 	struct mei_cl_cb *cb, *next;
812 
813 	cl = NULL;
814 	list_for_each_entry_safe(cb, next, &dev->ctrl_rd_list.list, list) {
815 
816 		cl = cb->cl;
817 
818 		if (cb->fop_type != fop_type)
819 			continue;
820 
821 		if (mei_hbm_cl_addr_equal(cl, rs)) {
822 			list_del_init(&cb->list);
823 			break;
824 		}
825 	}
826 
827 	if (!cl)
828 		return;
829 
830 	switch (fop_type) {
831 	case MEI_FOP_CONNECT:
832 		mei_hbm_cl_connect_res(dev, cl, rs);
833 		break;
834 	case MEI_FOP_DISCONNECT:
835 		mei_hbm_cl_disconnect_res(dev, cl, rs);
836 		break;
837 	case MEI_FOP_NOTIFY_START:
838 		mei_hbm_cl_notify_start_res(dev, cl, rs);
839 		break;
840 	case MEI_FOP_NOTIFY_STOP:
841 		mei_hbm_cl_notify_stop_res(dev, cl, rs);
842 		break;
843 	default:
844 		return;
845 	}
846 
847 	cl->timer_count = 0;
848 	wake_up(&cl->wait);
849 }
850 
851 
852 /**
853  * mei_hbm_fw_disconnect_req - disconnect request initiated by ME firmware
854  *  host sends disconnect response
855  *
856  * @dev: the device structure.
857  * @disconnect_req: disconnect request bus message from the me
858  *
859  * Return: -ENOMEM on allocation failure
860  */
861 static int mei_hbm_fw_disconnect_req(struct mei_device *dev,
862 		struct hbm_client_connect_request *disconnect_req)
863 {
864 	struct mei_cl *cl;
865 	struct mei_cl_cb *cb;
866 
867 	cl = mei_hbm_cl_find_by_cmd(dev, disconnect_req);
868 	if (cl) {
869 		cl_dbg(dev, cl, "fw disconnect request received\n");
870 		cl->state = MEI_FILE_DISCONNECTING;
871 		cl->timer_count = 0;
872 
873 		cb = mei_io_cb_init(cl, MEI_FOP_DISCONNECT_RSP, NULL);
874 		if (!cb)
875 			return -ENOMEM;
876 		cl_dbg(dev, cl, "add disconnect response as first\n");
877 		list_add(&cb->list, &dev->ctrl_wr_list.list);
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 	/* disconnect on connect timeout instead of link reset */
976 	if (dev->version.major_version >= HBM_MAJOR_VERSION_DOT)
977 		dev->hbm_f_dot_supported = 1;
978 
979 	/* Notification Event Support */
980 	if (dev->version.major_version >= HBM_MAJOR_VERSION_EV)
981 		dev->hbm_f_ev_supported = 1;
982 }
983 
984 /**
985  * mei_hbm_version_is_supported - checks whether the driver can
986  *     support the hbm version of the device
987  *
988  * @dev: the device structure
989  * Return: true if driver can support hbm version of the device
990  */
991 bool mei_hbm_version_is_supported(struct mei_device *dev)
992 {
993 	return	(dev->version.major_version < HBM_MAJOR_VERSION) ||
994 		(dev->version.major_version == HBM_MAJOR_VERSION &&
995 		 dev->version.minor_version <= HBM_MINOR_VERSION);
996 }
997 
998 /**
999  * mei_hbm_dispatch - bottom half read routine after ISR to
1000  * handle the read bus message cmd processing.
1001  *
1002  * @dev: the device structure
1003  * @hdr: header of bus message
1004  *
1005  * Return: 0 on success and < 0 on failure
1006  */
1007 int mei_hbm_dispatch(struct mei_device *dev, struct mei_msg_hdr *hdr)
1008 {
1009 	struct mei_bus_message *mei_msg;
1010 	struct hbm_host_version_response *version_res;
1011 	struct hbm_props_response *props_res;
1012 	struct hbm_host_enum_response *enum_res;
1013 	struct hbm_add_client_request *add_cl_req;
1014 	int ret;
1015 
1016 	struct mei_hbm_cl_cmd *cl_cmd;
1017 	struct hbm_client_connect_request *disconnect_req;
1018 	struct hbm_flow_control *flow_control;
1019 
1020 	/* read the message to our buffer */
1021 	BUG_ON(hdr->length >= sizeof(dev->rd_msg_buf));
1022 	mei_read_slots(dev, dev->rd_msg_buf, hdr->length);
1023 	mei_msg = (struct mei_bus_message *)dev->rd_msg_buf;
1024 	cl_cmd  = (struct mei_hbm_cl_cmd *)mei_msg;
1025 
1026 	/* ignore spurious message and prevent reset nesting
1027 	 * hbm is put to idle during system reset
1028 	 */
1029 	if (dev->hbm_state == MEI_HBM_IDLE) {
1030 		dev_dbg(dev->dev, "hbm: state is idle ignore spurious messages\n");
1031 		return 0;
1032 	}
1033 
1034 	switch (mei_msg->hbm_cmd) {
1035 	case HOST_START_RES_CMD:
1036 		dev_dbg(dev->dev, "hbm: start: response message received.\n");
1037 
1038 		dev->init_clients_timer = 0;
1039 
1040 		version_res = (struct hbm_host_version_response *)mei_msg;
1041 
1042 		dev_dbg(dev->dev, "HBM VERSION: DRIVER=%02d:%02d DEVICE=%02d:%02d\n",
1043 				HBM_MAJOR_VERSION, HBM_MINOR_VERSION,
1044 				version_res->me_max_version.major_version,
1045 				version_res->me_max_version.minor_version);
1046 
1047 		if (version_res->host_version_supported) {
1048 			dev->version.major_version = HBM_MAJOR_VERSION;
1049 			dev->version.minor_version = HBM_MINOR_VERSION;
1050 		} else {
1051 			dev->version.major_version =
1052 				version_res->me_max_version.major_version;
1053 			dev->version.minor_version =
1054 				version_res->me_max_version.minor_version;
1055 		}
1056 
1057 		if (!mei_hbm_version_is_supported(dev)) {
1058 			dev_warn(dev->dev, "hbm: start: version mismatch - stopping the driver.\n");
1059 
1060 			dev->hbm_state = MEI_HBM_STOPPED;
1061 			if (mei_hbm_stop_req(dev)) {
1062 				dev_err(dev->dev, "hbm: start: failed to send stop request\n");
1063 				return -EIO;
1064 			}
1065 			break;
1066 		}
1067 
1068 		mei_hbm_config_features(dev);
1069 
1070 		if (dev->dev_state != MEI_DEV_INIT_CLIENTS ||
1071 		    dev->hbm_state != MEI_HBM_STARTING) {
1072 			dev_err(dev->dev, "hbm: start: state mismatch, [%d, %d]\n",
1073 				dev->dev_state, dev->hbm_state);
1074 			return -EPROTO;
1075 		}
1076 
1077 		if (mei_hbm_enum_clients_req(dev)) {
1078 			dev_err(dev->dev, "hbm: start: failed to send enumeration request\n");
1079 			return -EIO;
1080 		}
1081 
1082 		wake_up(&dev->wait_hbm_start);
1083 		break;
1084 
1085 	case CLIENT_CONNECT_RES_CMD:
1086 		dev_dbg(dev->dev, "hbm: client connect response: message received.\n");
1087 		mei_hbm_cl_res(dev, cl_cmd, MEI_FOP_CONNECT);
1088 		break;
1089 
1090 	case CLIENT_DISCONNECT_RES_CMD:
1091 		dev_dbg(dev->dev, "hbm: client disconnect response: message received.\n");
1092 		mei_hbm_cl_res(dev, cl_cmd, MEI_FOP_DISCONNECT);
1093 		break;
1094 
1095 	case MEI_FLOW_CONTROL_CMD:
1096 		dev_dbg(dev->dev, "hbm: client flow control response: message received.\n");
1097 
1098 		flow_control = (struct hbm_flow_control *) mei_msg;
1099 		mei_hbm_cl_flow_control_res(dev, flow_control);
1100 		break;
1101 
1102 	case MEI_PG_ISOLATION_ENTRY_RES_CMD:
1103 		dev_dbg(dev->dev, "hbm: power gate isolation entry response received\n");
1104 		ret = mei_hbm_pg_enter_res(dev);
1105 		if (ret)
1106 			return ret;
1107 		break;
1108 
1109 	case MEI_PG_ISOLATION_EXIT_REQ_CMD:
1110 		dev_dbg(dev->dev, "hbm: power gate isolation exit request received\n");
1111 		ret = mei_hbm_pg_exit_res(dev);
1112 		if (ret)
1113 			return ret;
1114 		break;
1115 
1116 	case HOST_CLIENT_PROPERTIES_RES_CMD:
1117 		dev_dbg(dev->dev, "hbm: properties response: message received.\n");
1118 
1119 		dev->init_clients_timer = 0;
1120 
1121 		if (dev->dev_state != MEI_DEV_INIT_CLIENTS ||
1122 		    dev->hbm_state != MEI_HBM_CLIENT_PROPERTIES) {
1123 			dev_err(dev->dev, "hbm: properties response: state mismatch, [%d, %d]\n",
1124 				dev->dev_state, dev->hbm_state);
1125 			return -EPROTO;
1126 		}
1127 
1128 		props_res = (struct hbm_props_response *)mei_msg;
1129 
1130 		if (props_res->status) {
1131 			dev_err(dev->dev, "hbm: properties response: wrong status = %d %s\n",
1132 				props_res->status,
1133 				mei_hbm_status_str(props_res->status));
1134 			return -EPROTO;
1135 		}
1136 
1137 		mei_hbm_me_cl_add(dev, props_res);
1138 
1139 		dev->me_client_index++;
1140 
1141 		/* request property for the next client */
1142 		if (mei_hbm_prop_req(dev))
1143 			return -EIO;
1144 
1145 		break;
1146 
1147 	case HOST_ENUM_RES_CMD:
1148 		dev_dbg(dev->dev, "hbm: enumeration response: message received\n");
1149 
1150 		dev->init_clients_timer = 0;
1151 
1152 		enum_res = (struct hbm_host_enum_response *) mei_msg;
1153 		BUILD_BUG_ON(sizeof(dev->me_clients_map)
1154 				< sizeof(enum_res->valid_addresses));
1155 		memcpy(dev->me_clients_map, enum_res->valid_addresses,
1156 				sizeof(enum_res->valid_addresses));
1157 
1158 		if (dev->dev_state != MEI_DEV_INIT_CLIENTS ||
1159 		    dev->hbm_state != MEI_HBM_ENUM_CLIENTS) {
1160 			dev_err(dev->dev, "hbm: enumeration response: state mismatch, [%d, %d]\n",
1161 				dev->dev_state, dev->hbm_state);
1162 			return -EPROTO;
1163 		}
1164 
1165 		dev->hbm_state = MEI_HBM_CLIENT_PROPERTIES;
1166 
1167 		/* first property request */
1168 		if (mei_hbm_prop_req(dev))
1169 			return -EIO;
1170 
1171 		break;
1172 
1173 	case HOST_STOP_RES_CMD:
1174 		dev_dbg(dev->dev, "hbm: stop response: message received\n");
1175 
1176 		dev->init_clients_timer = 0;
1177 
1178 		if (dev->hbm_state != MEI_HBM_STOPPED) {
1179 			dev_err(dev->dev, "hbm: stop response: state mismatch, [%d, %d]\n",
1180 				dev->dev_state, dev->hbm_state);
1181 			return -EPROTO;
1182 		}
1183 
1184 		dev->dev_state = MEI_DEV_POWER_DOWN;
1185 		dev_info(dev->dev, "hbm: stop response: resetting.\n");
1186 		/* force the reset */
1187 		return -EPROTO;
1188 		break;
1189 
1190 	case CLIENT_DISCONNECT_REQ_CMD:
1191 		dev_dbg(dev->dev, "hbm: disconnect request: message received\n");
1192 
1193 		disconnect_req = (struct hbm_client_connect_request *)mei_msg;
1194 		mei_hbm_fw_disconnect_req(dev, disconnect_req);
1195 		break;
1196 
1197 	case ME_STOP_REQ_CMD:
1198 		dev_dbg(dev->dev, "hbm: stop request: message received\n");
1199 		dev->hbm_state = MEI_HBM_STOPPED;
1200 		if (mei_hbm_stop_req(dev)) {
1201 			dev_err(dev->dev, "hbm: stop request: failed to send stop request\n");
1202 			return -EIO;
1203 		}
1204 		break;
1205 
1206 	case MEI_HBM_ADD_CLIENT_REQ_CMD:
1207 		dev_dbg(dev->dev, "hbm: add client request received\n");
1208 		/*
1209 		 * after the host receives the enum_resp
1210 		 * message clients may be added or removed
1211 		 */
1212 		if (dev->hbm_state <= MEI_HBM_ENUM_CLIENTS ||
1213 		    dev->hbm_state >= MEI_HBM_STOPPED) {
1214 			dev_err(dev->dev, "hbm: add client: state mismatch, [%d, %d]\n",
1215 				dev->dev_state, dev->hbm_state);
1216 			return -EPROTO;
1217 		}
1218 		add_cl_req = (struct hbm_add_client_request *)mei_msg;
1219 		ret = mei_hbm_fw_add_cl_req(dev, add_cl_req);
1220 		if (ret) {
1221 			dev_err(dev->dev, "hbm: add client: failed to send response %d\n",
1222 				ret);
1223 			return -EIO;
1224 		}
1225 		dev_dbg(dev->dev, "hbm: add client request processed\n");
1226 		break;
1227 
1228 	case MEI_HBM_NOTIFY_RES_CMD:
1229 		dev_dbg(dev->dev, "hbm: notify response received\n");
1230 		mei_hbm_cl_res(dev, cl_cmd, notify_res_to_fop(cl_cmd));
1231 		break;
1232 
1233 	case MEI_HBM_NOTIFICATION_CMD:
1234 		dev_dbg(dev->dev, "hbm: notification\n");
1235 		mei_hbm_cl_notify(dev, cl_cmd);
1236 		break;
1237 
1238 	default:
1239 		BUG();
1240 		break;
1241 
1242 	}
1243 	return 0;
1244 }
1245 
1246