xref: /openbmc/linux/drivers/misc/mei/hbm.c (revision 3805e6a1)
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 }
136 
137 /**
138  * mei_hbm_cl_hdr - construct client hbm header
139  *
140  * @cl: client
141  * @hbm_cmd: host bus message command
142  * @buf: buffer for cl header
143  * @len: buffer length
144  */
145 static inline
146 void mei_hbm_cl_hdr(struct mei_cl *cl, u8 hbm_cmd, void *buf, size_t len)
147 {
148 	struct mei_hbm_cl_cmd *cmd = buf;
149 
150 	memset(cmd, 0, len);
151 
152 	cmd->hbm_cmd = hbm_cmd;
153 	cmd->host_addr = mei_cl_host_addr(cl);
154 	cmd->me_addr = mei_cl_me_id(cl);
155 }
156 
157 /**
158  * mei_hbm_cl_write - write simple hbm client message
159  *
160  * @dev: the device structure
161  * @cl: client
162  * @hbm_cmd: host bus message command
163  * @len: buffer length
164  *
165  * Return: 0 on success, <0 on failure.
166  */
167 static inline
168 int mei_hbm_cl_write(struct mei_device *dev,
169 		     struct mei_cl *cl, u8 hbm_cmd, size_t len)
170 {
171 	struct mei_msg_hdr *mei_hdr = &dev->wr_msg.hdr;
172 
173 	mei_hbm_hdr(mei_hdr, len);
174 	mei_hbm_cl_hdr(cl, hbm_cmd, dev->wr_msg.data, len);
175 
176 	return mei_write_message(dev, mei_hdr, dev->wr_msg.data);
177 }
178 
179 /**
180  * mei_hbm_cl_addr_equal - check if the client's and
181  *	the message address match
182  *
183  * @cl: client
184  * @cmd: hbm client message
185  *
186  * Return: true if addresses are the same
187  */
188 static inline
189 bool mei_hbm_cl_addr_equal(struct mei_cl *cl, struct mei_hbm_cl_cmd *cmd)
190 {
191 	return  mei_cl_host_addr(cl) == cmd->host_addr &&
192 		mei_cl_me_id(cl) == cmd->me_addr;
193 }
194 
195 /**
196  * mei_hbm_cl_find_by_cmd - find recipient client
197  *
198  * @dev: the device structure
199  * @buf: a buffer with hbm cl command
200  *
201  * Return: the recipient client or NULL if not found
202  */
203 static inline
204 struct mei_cl *mei_hbm_cl_find_by_cmd(struct mei_device *dev, void *buf)
205 {
206 	struct mei_hbm_cl_cmd *cmd = (struct mei_hbm_cl_cmd *)buf;
207 	struct mei_cl *cl;
208 
209 	list_for_each_entry(cl, &dev->file_list, link)
210 		if (mei_hbm_cl_addr_equal(cl, cmd))
211 			return cl;
212 	return NULL;
213 }
214 
215 
216 /**
217  * mei_hbm_start_wait - wait for start response message.
218  *
219  * @dev: the device structure
220  *
221  * Return: 0 on success and < 0 on failure
222  */
223 int mei_hbm_start_wait(struct mei_device *dev)
224 {
225 	int ret;
226 
227 	if (dev->hbm_state > MEI_HBM_STARTING)
228 		return 0;
229 
230 	mutex_unlock(&dev->device_lock);
231 	ret = wait_event_timeout(dev->wait_hbm_start,
232 			dev->hbm_state != MEI_HBM_STARTING,
233 			mei_secs_to_jiffies(MEI_HBM_TIMEOUT));
234 	mutex_lock(&dev->device_lock);
235 
236 	if (ret == 0 && (dev->hbm_state <= MEI_HBM_STARTING)) {
237 		dev->hbm_state = MEI_HBM_IDLE;
238 		dev_err(dev->dev, "waiting for mei start failed\n");
239 		return -ETIME;
240 	}
241 	return 0;
242 }
243 
244 /**
245  * mei_hbm_start_req - sends start request message.
246  *
247  * @dev: the device structure
248  *
249  * Return: 0 on success and < 0 on failure
250  */
251 int mei_hbm_start_req(struct mei_device *dev)
252 {
253 	struct mei_msg_hdr *mei_hdr = &dev->wr_msg.hdr;
254 	struct hbm_host_version_request *start_req;
255 	const size_t len = sizeof(struct hbm_host_version_request);
256 	int ret;
257 
258 	mei_hbm_reset(dev);
259 
260 	mei_hbm_hdr(mei_hdr, len);
261 
262 	/* host start message */
263 	start_req = (struct hbm_host_version_request *)dev->wr_msg.data;
264 	memset(start_req, 0, len);
265 	start_req->hbm_cmd = HOST_START_REQ_CMD;
266 	start_req->host_version.major_version = HBM_MAJOR_VERSION;
267 	start_req->host_version.minor_version = HBM_MINOR_VERSION;
268 
269 	dev->hbm_state = MEI_HBM_IDLE;
270 	ret = mei_write_message(dev, mei_hdr, dev->wr_msg.data);
271 	if (ret) {
272 		dev_err(dev->dev, "version message write failed: ret = %d\n",
273 			ret);
274 		return ret;
275 	}
276 
277 	dev->hbm_state = MEI_HBM_STARTING;
278 	dev->init_clients_timer = MEI_CLIENTS_INIT_TIMEOUT;
279 	return 0;
280 }
281 
282 /**
283  * mei_hbm_enum_clients_req - sends enumeration client request message.
284  *
285  * @dev: the device structure
286  *
287  * Return: 0 on success and < 0 on failure
288  */
289 static int mei_hbm_enum_clients_req(struct mei_device *dev)
290 {
291 	struct mei_msg_hdr *mei_hdr = &dev->wr_msg.hdr;
292 	struct hbm_host_enum_request *enum_req;
293 	const size_t len = sizeof(struct hbm_host_enum_request);
294 	int ret;
295 
296 	/* enumerate clients */
297 	mei_hbm_hdr(mei_hdr, len);
298 
299 	enum_req = (struct hbm_host_enum_request *)dev->wr_msg.data;
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, dev->wr_msg.data);
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->mei_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 = &dev->wr_msg.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 	resp = (struct hbm_add_client_response *)dev->wr_msg.data;
369 
370 	mei_hbm_hdr(mei_hdr, len);
371 	memset(resp, 0, sizeof(struct hbm_add_client_response));
372 
373 	resp->hbm_cmd = MEI_HBM_ADD_CLIENT_RES_CMD;
374 	resp->me_addr = addr;
375 	resp->status  = status;
376 
377 	ret = mei_write_message(dev, mei_hdr, dev->wr_msg.data);
378 	if (ret)
379 		dev_err(dev->dev, "add client response write failed: ret = %d\n",
380 			ret);
381 	return ret;
382 }
383 
384 /**
385  * mei_hbm_fw_add_cl_req - request from the fw to add a client
386  *
387  * @dev: the device structure
388  * @req: add client request
389  *
390  * Return: 0 on success and < 0 on failure
391  */
392 static int mei_hbm_fw_add_cl_req(struct mei_device *dev,
393 			      struct hbm_add_client_request *req)
394 {
395 	int ret;
396 	u8 status = MEI_HBMS_SUCCESS;
397 
398 	BUILD_BUG_ON(sizeof(struct hbm_add_client_request) !=
399 			sizeof(struct hbm_props_response));
400 
401 	ret = mei_hbm_me_cl_add(dev, (struct hbm_props_response *)req);
402 	if (ret)
403 		status = !MEI_HBMS_SUCCESS;
404 
405 	if (dev->dev_state == MEI_DEV_ENABLED)
406 		schedule_work(&dev->bus_rescan_work);
407 
408 	return mei_hbm_add_cl_resp(dev, req->me_addr, status);
409 }
410 
411 /**
412  * mei_hbm_cl_notify_req - send notification request
413  *
414  * @dev: the device structure
415  * @cl: a client to disconnect from
416  * @start: true for start false for stop
417  *
418  * Return: 0 on success and -EIO on write failure
419  */
420 int mei_hbm_cl_notify_req(struct mei_device *dev,
421 			  struct mei_cl *cl, u8 start)
422 {
423 
424 	struct mei_msg_hdr *mei_hdr = &dev->wr_msg.hdr;
425 	struct hbm_notification_request *req;
426 	const size_t len = sizeof(struct hbm_notification_request);
427 	int ret;
428 
429 	mei_hbm_hdr(mei_hdr, len);
430 	mei_hbm_cl_hdr(cl, MEI_HBM_NOTIFY_REQ_CMD, dev->wr_msg.data, len);
431 
432 	req = (struct hbm_notification_request *)dev->wr_msg.data;
433 	req->start = start;
434 
435 	ret = mei_write_message(dev, mei_hdr, dev->wr_msg.data);
436 	if (ret)
437 		dev_err(dev->dev, "notify request failed: ret = %d\n", ret);
438 
439 	return ret;
440 }
441 
442 /**
443  *  notify_res_to_fop - convert notification response to the proper
444  *      notification FOP
445  *
446  * @cmd: client notification start response command
447  *
448  * Return:  MEI_FOP_NOTIFY_START or MEI_FOP_NOTIFY_STOP;
449  */
450 static inline enum mei_cb_file_ops notify_res_to_fop(struct mei_hbm_cl_cmd *cmd)
451 {
452 	struct hbm_notification_response *rs =
453 		(struct hbm_notification_response *)cmd;
454 
455 	return mei_cl_notify_req2fop(rs->start);
456 }
457 
458 /**
459  * mei_hbm_cl_notify_start_res - update the client state according
460  *       notify start response
461  *
462  * @dev: the device structure
463  * @cl: mei host client
464  * @cmd: client notification start response command
465  */
466 static void mei_hbm_cl_notify_start_res(struct mei_device *dev,
467 					struct mei_cl *cl,
468 					struct mei_hbm_cl_cmd *cmd)
469 {
470 	struct hbm_notification_response *rs =
471 		(struct hbm_notification_response *)cmd;
472 
473 	cl_dbg(dev, cl, "hbm: notify start response status=%d\n", rs->status);
474 
475 	if (rs->status == MEI_HBMS_SUCCESS ||
476 	    rs->status == MEI_HBMS_ALREADY_STARTED) {
477 		cl->notify_en = true;
478 		cl->status = 0;
479 	} else {
480 		cl->status = -EINVAL;
481 	}
482 }
483 
484 /**
485  * mei_hbm_cl_notify_stop_res - update the client state according
486  *       notify stop response
487  *
488  * @dev: the device structure
489  * @cl: mei host client
490  * @cmd: client notification stop response command
491  */
492 static void mei_hbm_cl_notify_stop_res(struct mei_device *dev,
493 				       struct mei_cl *cl,
494 				       struct mei_hbm_cl_cmd *cmd)
495 {
496 	struct hbm_notification_response *rs =
497 		(struct hbm_notification_response *)cmd;
498 
499 	cl_dbg(dev, cl, "hbm: notify stop response status=%d\n", rs->status);
500 
501 	if (rs->status == MEI_HBMS_SUCCESS ||
502 	    rs->status == MEI_HBMS_NOT_STARTED) {
503 		cl->notify_en = false;
504 		cl->status = 0;
505 	} else {
506 		/* TODO: spec is not clear yet about other possible issues */
507 		cl->status = -EINVAL;
508 	}
509 }
510 
511 /**
512  * mei_hbm_cl_notify - signal notification event
513  *
514  * @dev: the device structure
515  * @cmd: notification client message
516  */
517 static void mei_hbm_cl_notify(struct mei_device *dev,
518 			      struct mei_hbm_cl_cmd *cmd)
519 {
520 	struct mei_cl *cl;
521 
522 	cl = mei_hbm_cl_find_by_cmd(dev, cmd);
523 	if (cl)
524 		mei_cl_notify(cl);
525 }
526 
527 /**
528  * mei_hbm_prop_req - request property for a single client
529  *
530  * @dev: the device structure
531  * @start_idx: client index to start search
532  *
533  * Return: 0 on success and < 0 on failure
534  */
535 static int mei_hbm_prop_req(struct mei_device *dev, unsigned long start_idx)
536 {
537 	struct mei_msg_hdr *mei_hdr = &dev->wr_msg.hdr;
538 	struct hbm_props_request *prop_req;
539 	const size_t len = sizeof(struct hbm_props_request);
540 	unsigned long addr;
541 	int ret;
542 
543 	addr = find_next_bit(dev->me_clients_map, MEI_CLIENTS_MAX, start_idx);
544 
545 	/* We got all client properties */
546 	if (addr == MEI_CLIENTS_MAX) {
547 		dev->hbm_state = MEI_HBM_STARTED;
548 		mei_host_client_init(dev);
549 
550 		return 0;
551 	}
552 
553 	mei_hbm_hdr(mei_hdr, len);
554 	prop_req = (struct hbm_props_request *)dev->wr_msg.data;
555 
556 	memset(prop_req, 0, sizeof(struct hbm_props_request));
557 
558 	prop_req->hbm_cmd = HOST_CLIENT_PROPERTIES_REQ_CMD;
559 	prop_req->me_addr = addr;
560 
561 	ret = mei_write_message(dev, mei_hdr, dev->wr_msg.data);
562 	if (ret) {
563 		dev_err(dev->dev, "properties request write failed: ret = %d\n",
564 			ret);
565 		return ret;
566 	}
567 
568 	dev->init_clients_timer = MEI_CLIENTS_INIT_TIMEOUT;
569 
570 	return 0;
571 }
572 
573 /**
574  * mei_hbm_pg - sends pg command
575  *
576  * @dev: the device structure
577  * @pg_cmd: the pg command code
578  *
579  * Return: -EIO on write failure
580  *         -EOPNOTSUPP if the operation is not supported by the protocol
581  */
582 int mei_hbm_pg(struct mei_device *dev, u8 pg_cmd)
583 {
584 	struct mei_msg_hdr *mei_hdr = &dev->wr_msg.hdr;
585 	struct hbm_power_gate *req;
586 	const size_t len = sizeof(struct hbm_power_gate);
587 	int ret;
588 
589 	if (!dev->hbm_f_pg_supported)
590 		return -EOPNOTSUPP;
591 
592 	mei_hbm_hdr(mei_hdr, len);
593 
594 	req = (struct hbm_power_gate *)dev->wr_msg.data;
595 	memset(req, 0, len);
596 	req->hbm_cmd = pg_cmd;
597 
598 	ret = mei_write_message(dev, mei_hdr, dev->wr_msg.data);
599 	if (ret)
600 		dev_err(dev->dev, "power gate command write failed.\n");
601 	return ret;
602 }
603 EXPORT_SYMBOL_GPL(mei_hbm_pg);
604 
605 /**
606  * mei_hbm_stop_req - send stop request message
607  *
608  * @dev: mei device
609  *
610  * Return: -EIO on write failure
611  */
612 static int mei_hbm_stop_req(struct mei_device *dev)
613 {
614 	struct mei_msg_hdr *mei_hdr = &dev->wr_msg.hdr;
615 	struct hbm_host_stop_request *req =
616 			(struct hbm_host_stop_request *)dev->wr_msg.data;
617 	const size_t len = sizeof(struct hbm_host_stop_request);
618 
619 	mei_hbm_hdr(mei_hdr, len);
620 
621 	memset(req, 0, len);
622 	req->hbm_cmd = HOST_STOP_REQ_CMD;
623 	req->reason = DRIVER_STOP_REQUEST;
624 
625 	return mei_write_message(dev, mei_hdr, dev->wr_msg.data);
626 }
627 
628 /**
629  * mei_hbm_cl_flow_control_req - sends flow control request.
630  *
631  * @dev: the device structure
632  * @cl: client info
633  *
634  * Return: -EIO on write failure
635  */
636 int mei_hbm_cl_flow_control_req(struct mei_device *dev, struct mei_cl *cl)
637 {
638 	const size_t len = sizeof(struct hbm_flow_control);
639 
640 	cl_dbg(dev, cl, "sending flow control\n");
641 	return mei_hbm_cl_write(dev, cl, MEI_FLOW_CONTROL_CMD, len);
642 }
643 
644 /**
645  * mei_hbm_add_single_flow_creds - adds single buffer credentials.
646  *
647  * @dev: the device structure
648  * @flow: flow control.
649  *
650  * Return: 0 on success, < 0 otherwise
651  */
652 static int mei_hbm_add_single_flow_creds(struct mei_device *dev,
653 				  struct hbm_flow_control *flow)
654 {
655 	struct mei_me_client *me_cl;
656 	int rets;
657 
658 	me_cl = mei_me_cl_by_id(dev, flow->me_addr);
659 	if (!me_cl) {
660 		dev_err(dev->dev, "no such me client %d\n",
661 			flow->me_addr);
662 		return -ENOENT;
663 	}
664 
665 	if (WARN_ON(me_cl->props.single_recv_buf == 0)) {
666 		rets = -EINVAL;
667 		goto out;
668 	}
669 
670 	me_cl->mei_flow_ctrl_creds++;
671 	dev_dbg(dev->dev, "recv flow ctrl msg ME %d (single) creds = %d.\n",
672 	    flow->me_addr, me_cl->mei_flow_ctrl_creds);
673 
674 	rets = 0;
675 out:
676 	mei_me_cl_put(me_cl);
677 	return rets;
678 }
679 
680 /**
681  * mei_hbm_cl_flow_control_res - flow control response from me
682  *
683  * @dev: the device structure
684  * @flow_control: flow control response bus message
685  */
686 static void mei_hbm_cl_flow_control_res(struct mei_device *dev,
687 					struct hbm_flow_control *flow_control)
688 {
689 	struct mei_cl *cl;
690 
691 	if (!flow_control->host_addr) {
692 		/* single receive buffer */
693 		mei_hbm_add_single_flow_creds(dev, flow_control);
694 		return;
695 	}
696 
697 	cl = mei_hbm_cl_find_by_cmd(dev, flow_control);
698 	if (cl) {
699 		cl->mei_flow_ctrl_creds++;
700 		cl_dbg(dev, cl, "flow control creds = %d.\n",
701 				cl->mei_flow_ctrl_creds);
702 	}
703 }
704 
705 
706 /**
707  * mei_hbm_cl_disconnect_req - sends disconnect message to fw.
708  *
709  * @dev: the device structure
710  * @cl: a client to disconnect from
711  *
712  * Return: -EIO on write failure
713  */
714 int mei_hbm_cl_disconnect_req(struct mei_device *dev, struct mei_cl *cl)
715 {
716 	const size_t len = sizeof(struct hbm_client_connect_request);
717 
718 	return mei_hbm_cl_write(dev, cl, CLIENT_DISCONNECT_REQ_CMD, len);
719 }
720 
721 /**
722  * mei_hbm_cl_disconnect_rsp - sends disconnect respose to the FW
723  *
724  * @dev: the device structure
725  * @cl: a client to disconnect from
726  *
727  * Return: -EIO on write failure
728  */
729 int mei_hbm_cl_disconnect_rsp(struct mei_device *dev, struct mei_cl *cl)
730 {
731 	const size_t len = sizeof(struct hbm_client_connect_response);
732 
733 	return mei_hbm_cl_write(dev, cl, CLIENT_DISCONNECT_RES_CMD, len);
734 }
735 
736 /**
737  * mei_hbm_cl_disconnect_res - update the client state according
738  *       disconnect response
739  *
740  * @dev: the device structure
741  * @cl: mei host client
742  * @cmd: disconnect client response host bus message
743  */
744 static void mei_hbm_cl_disconnect_res(struct mei_device *dev, struct mei_cl *cl,
745 				      struct mei_hbm_cl_cmd *cmd)
746 {
747 	struct hbm_client_connect_response *rs =
748 		(struct hbm_client_connect_response *)cmd;
749 
750 	cl_dbg(dev, cl, "hbm: disconnect response status=%d\n", rs->status);
751 
752 	if (rs->status == MEI_CL_DISCONN_SUCCESS)
753 		cl->state = MEI_FILE_DISCONNECT_REPLY;
754 	cl->status = 0;
755 }
756 
757 /**
758  * mei_hbm_cl_connect_req - send connection request to specific me client
759  *
760  * @dev: the device structure
761  * @cl: a client to connect to
762  *
763  * Return: -EIO on write failure
764  */
765 int mei_hbm_cl_connect_req(struct mei_device *dev, struct mei_cl *cl)
766 {
767 	const size_t len = sizeof(struct hbm_client_connect_request);
768 
769 	return mei_hbm_cl_write(dev, cl, CLIENT_CONNECT_REQ_CMD, len);
770 }
771 
772 /**
773  * mei_hbm_cl_connect_res - update the client state according
774  *        connection response
775  *
776  * @dev: the device structure
777  * @cl: mei host client
778  * @cmd: connect client response host bus message
779  */
780 static void mei_hbm_cl_connect_res(struct mei_device *dev, struct mei_cl *cl,
781 				   struct mei_hbm_cl_cmd *cmd)
782 {
783 	struct hbm_client_connect_response *rs =
784 		(struct hbm_client_connect_response *)cmd;
785 
786 	cl_dbg(dev, cl, "hbm: connect response status=%s\n",
787 			mei_cl_conn_status_str(rs->status));
788 
789 	if (rs->status == MEI_CL_CONN_SUCCESS)
790 		cl->state = MEI_FILE_CONNECTED;
791 	else {
792 		cl->state = MEI_FILE_DISCONNECT_REPLY;
793 		if (rs->status == MEI_CL_CONN_NOT_FOUND) {
794 			mei_me_cl_del(dev, cl->me_cl);
795 			if (dev->dev_state == MEI_DEV_ENABLED)
796 				schedule_work(&dev->bus_rescan_work);
797 		}
798 	}
799 	cl->status = mei_cl_conn_status_to_errno(rs->status);
800 }
801 
802 /**
803  * mei_hbm_cl_res - process hbm response received on behalf
804  *         an client
805  *
806  * @dev: the device structure
807  * @rs:  hbm client message
808  * @fop_type: file operation type
809  */
810 static void mei_hbm_cl_res(struct mei_device *dev,
811 			   struct mei_hbm_cl_cmd *rs,
812 			   enum mei_cb_file_ops fop_type)
813 {
814 	struct mei_cl *cl;
815 	struct mei_cl_cb *cb, *next;
816 
817 	cl = NULL;
818 	list_for_each_entry_safe(cb, next, &dev->ctrl_rd_list.list, list) {
819 
820 		cl = cb->cl;
821 
822 		if (cb->fop_type != fop_type)
823 			continue;
824 
825 		if (mei_hbm_cl_addr_equal(cl, rs)) {
826 			list_del_init(&cb->list);
827 			break;
828 		}
829 	}
830 
831 	if (!cl)
832 		return;
833 
834 	switch (fop_type) {
835 	case MEI_FOP_CONNECT:
836 		mei_hbm_cl_connect_res(dev, cl, rs);
837 		break;
838 	case MEI_FOP_DISCONNECT:
839 		mei_hbm_cl_disconnect_res(dev, cl, rs);
840 		break;
841 	case MEI_FOP_NOTIFY_START:
842 		mei_hbm_cl_notify_start_res(dev, cl, rs);
843 		break;
844 	case MEI_FOP_NOTIFY_STOP:
845 		mei_hbm_cl_notify_stop_res(dev, cl, rs);
846 		break;
847 	default:
848 		return;
849 	}
850 
851 	cl->timer_count = 0;
852 	wake_up(&cl->wait);
853 }
854 
855 
856 /**
857  * mei_hbm_fw_disconnect_req - disconnect request initiated by ME firmware
858  *  host sends disconnect response
859  *
860  * @dev: the device structure.
861  * @disconnect_req: disconnect request bus message from the me
862  *
863  * Return: -ENOMEM on allocation failure
864  */
865 static int mei_hbm_fw_disconnect_req(struct mei_device *dev,
866 		struct hbm_client_connect_request *disconnect_req)
867 {
868 	struct mei_cl *cl;
869 	struct mei_cl_cb *cb;
870 
871 	cl = mei_hbm_cl_find_by_cmd(dev, disconnect_req);
872 	if (cl) {
873 		cl_warn(dev, cl, "fw disconnect request received\n");
874 		cl->state = MEI_FILE_DISCONNECTING;
875 		cl->timer_count = 0;
876 
877 		cb = mei_io_cb_init(cl, MEI_FOP_DISCONNECT_RSP, NULL);
878 		if (!cb)
879 			return -ENOMEM;
880 		list_add_tail(&cb->list, &dev->ctrl_wr_list.list);
881 	}
882 	return 0;
883 }
884 
885 /**
886  * mei_hbm_pg_enter_res - PG enter response received
887  *
888  * @dev: the device structure.
889  *
890  * Return: 0 on success, -EPROTO on state mismatch
891  */
892 static int mei_hbm_pg_enter_res(struct mei_device *dev)
893 {
894 	if (mei_pg_state(dev) != MEI_PG_OFF ||
895 	    dev->pg_event != MEI_PG_EVENT_WAIT) {
896 		dev_err(dev->dev, "hbm: pg entry response: state mismatch [%s, %d]\n",
897 			mei_pg_state_str(mei_pg_state(dev)), dev->pg_event);
898 		return -EPROTO;
899 	}
900 
901 	dev->pg_event = MEI_PG_EVENT_RECEIVED;
902 	wake_up(&dev->wait_pg);
903 
904 	return 0;
905 }
906 
907 /**
908  * mei_hbm_pg_resume - process with PG resume
909  *
910  * @dev: the device structure.
911  */
912 void mei_hbm_pg_resume(struct mei_device *dev)
913 {
914 	pm_request_resume(dev->dev);
915 }
916 EXPORT_SYMBOL_GPL(mei_hbm_pg_resume);
917 
918 /**
919  * mei_hbm_pg_exit_res - PG exit response received
920  *
921  * @dev: the device structure.
922  *
923  * Return: 0 on success, -EPROTO on state mismatch
924  */
925 static int mei_hbm_pg_exit_res(struct mei_device *dev)
926 {
927 	if (mei_pg_state(dev) != MEI_PG_ON ||
928 	    (dev->pg_event != MEI_PG_EVENT_WAIT &&
929 	     dev->pg_event != MEI_PG_EVENT_IDLE)) {
930 		dev_err(dev->dev, "hbm: pg exit response: state mismatch [%s, %d]\n",
931 			mei_pg_state_str(mei_pg_state(dev)), dev->pg_event);
932 		return -EPROTO;
933 	}
934 
935 	switch (dev->pg_event) {
936 	case MEI_PG_EVENT_WAIT:
937 		dev->pg_event = MEI_PG_EVENT_RECEIVED;
938 		wake_up(&dev->wait_pg);
939 		break;
940 	case MEI_PG_EVENT_IDLE:
941 		/*
942 		* If the driver is not waiting on this then
943 		* this is HW initiated exit from PG.
944 		* Start runtime pm resume sequence to exit from PG.
945 		*/
946 		dev->pg_event = MEI_PG_EVENT_RECEIVED;
947 		mei_hbm_pg_resume(dev);
948 		break;
949 	default:
950 		WARN(1, "hbm: pg exit response: unexpected pg event = %d\n",
951 		     dev->pg_event);
952 		return -EPROTO;
953 	}
954 
955 	return 0;
956 }
957 
958 /**
959  * mei_hbm_config_features - check what hbm features and commands
960  *        are supported by the fw
961  *
962  * @dev: the device structure
963  */
964 static void mei_hbm_config_features(struct mei_device *dev)
965 {
966 	/* Power Gating Isolation Support */
967 	dev->hbm_f_pg_supported = 0;
968 	if (dev->version.major_version > HBM_MAJOR_VERSION_PGI)
969 		dev->hbm_f_pg_supported = 1;
970 
971 	if (dev->version.major_version == HBM_MAJOR_VERSION_PGI &&
972 	    dev->version.minor_version >= HBM_MINOR_VERSION_PGI)
973 		dev->hbm_f_pg_supported = 1;
974 
975 	if (dev->version.major_version >= HBM_MAJOR_VERSION_DC)
976 		dev->hbm_f_dc_supported = 1;
977 
978 	if (dev->version.major_version >= HBM_MAJOR_VERSION_IE)
979 		dev->hbm_f_ie_supported = 1;
980 
981 	/* disconnect on connect timeout instead of link reset */
982 	if (dev->version.major_version >= HBM_MAJOR_VERSION_DOT)
983 		dev->hbm_f_dot_supported = 1;
984 
985 	/* Notification Event Support */
986 	if (dev->version.major_version >= HBM_MAJOR_VERSION_EV)
987 		dev->hbm_f_ev_supported = 1;
988 
989 	/* Fixed Address Client Support */
990 	if (dev->version.major_version >= HBM_MAJOR_VERSION_FA)
991 		dev->hbm_f_fa_supported = 1;
992 }
993 
994 /**
995  * mei_hbm_version_is_supported - checks whether the driver can
996  *     support the hbm version of the device
997  *
998  * @dev: the device structure
999  * Return: true if driver can support hbm version of the device
1000  */
1001 bool mei_hbm_version_is_supported(struct mei_device *dev)
1002 {
1003 	return	(dev->version.major_version < HBM_MAJOR_VERSION) ||
1004 		(dev->version.major_version == HBM_MAJOR_VERSION &&
1005 		 dev->version.minor_version <= HBM_MINOR_VERSION);
1006 }
1007 
1008 /**
1009  * mei_hbm_dispatch - bottom half read routine after ISR to
1010  * handle the read bus message cmd processing.
1011  *
1012  * @dev: the device structure
1013  * @hdr: header of bus message
1014  *
1015  * Return: 0 on success and < 0 on failure
1016  */
1017 int mei_hbm_dispatch(struct mei_device *dev, struct mei_msg_hdr *hdr)
1018 {
1019 	struct mei_bus_message *mei_msg;
1020 	struct hbm_host_version_response *version_res;
1021 	struct hbm_props_response *props_res;
1022 	struct hbm_host_enum_response *enum_res;
1023 	struct hbm_add_client_request *add_cl_req;
1024 	int ret;
1025 
1026 	struct mei_hbm_cl_cmd *cl_cmd;
1027 	struct hbm_client_connect_request *disconnect_req;
1028 	struct hbm_flow_control *flow_control;
1029 
1030 	/* read the message to our buffer */
1031 	BUG_ON(hdr->length >= sizeof(dev->rd_msg_buf));
1032 	mei_read_slots(dev, dev->rd_msg_buf, hdr->length);
1033 	mei_msg = (struct mei_bus_message *)dev->rd_msg_buf;
1034 	cl_cmd  = (struct mei_hbm_cl_cmd *)mei_msg;
1035 
1036 	/* ignore spurious message and prevent reset nesting
1037 	 * hbm is put to idle during system reset
1038 	 */
1039 	if (dev->hbm_state == MEI_HBM_IDLE) {
1040 		dev_dbg(dev->dev, "hbm: state is idle ignore spurious messages\n");
1041 		return 0;
1042 	}
1043 
1044 	switch (mei_msg->hbm_cmd) {
1045 	case HOST_START_RES_CMD:
1046 		dev_dbg(dev->dev, "hbm: start: response message received.\n");
1047 
1048 		dev->init_clients_timer = 0;
1049 
1050 		version_res = (struct hbm_host_version_response *)mei_msg;
1051 
1052 		dev_dbg(dev->dev, "HBM VERSION: DRIVER=%02d:%02d DEVICE=%02d:%02d\n",
1053 				HBM_MAJOR_VERSION, HBM_MINOR_VERSION,
1054 				version_res->me_max_version.major_version,
1055 				version_res->me_max_version.minor_version);
1056 
1057 		if (version_res->host_version_supported) {
1058 			dev->version.major_version = HBM_MAJOR_VERSION;
1059 			dev->version.minor_version = HBM_MINOR_VERSION;
1060 		} else {
1061 			dev->version.major_version =
1062 				version_res->me_max_version.major_version;
1063 			dev->version.minor_version =
1064 				version_res->me_max_version.minor_version;
1065 		}
1066 
1067 		if (!mei_hbm_version_is_supported(dev)) {
1068 			dev_warn(dev->dev, "hbm: start: version mismatch - stopping the driver.\n");
1069 
1070 			dev->hbm_state = MEI_HBM_STOPPED;
1071 			if (mei_hbm_stop_req(dev)) {
1072 				dev_err(dev->dev, "hbm: start: failed to send stop request\n");
1073 				return -EIO;
1074 			}
1075 			break;
1076 		}
1077 
1078 		mei_hbm_config_features(dev);
1079 
1080 		if (dev->dev_state != MEI_DEV_INIT_CLIENTS ||
1081 		    dev->hbm_state != MEI_HBM_STARTING) {
1082 			dev_err(dev->dev, "hbm: start: state mismatch, [%d, %d]\n",
1083 				dev->dev_state, dev->hbm_state);
1084 			return -EPROTO;
1085 		}
1086 
1087 		if (mei_hbm_enum_clients_req(dev)) {
1088 			dev_err(dev->dev, "hbm: start: failed to send enumeration request\n");
1089 			return -EIO;
1090 		}
1091 
1092 		wake_up(&dev->wait_hbm_start);
1093 		break;
1094 
1095 	case CLIENT_CONNECT_RES_CMD:
1096 		dev_dbg(dev->dev, "hbm: client connect response: message received.\n");
1097 		mei_hbm_cl_res(dev, cl_cmd, MEI_FOP_CONNECT);
1098 		break;
1099 
1100 	case CLIENT_DISCONNECT_RES_CMD:
1101 		dev_dbg(dev->dev, "hbm: client disconnect response: message received.\n");
1102 		mei_hbm_cl_res(dev, cl_cmd, MEI_FOP_DISCONNECT);
1103 		break;
1104 
1105 	case MEI_FLOW_CONTROL_CMD:
1106 		dev_dbg(dev->dev, "hbm: client flow control response: message received.\n");
1107 
1108 		flow_control = (struct hbm_flow_control *) mei_msg;
1109 		mei_hbm_cl_flow_control_res(dev, flow_control);
1110 		break;
1111 
1112 	case MEI_PG_ISOLATION_ENTRY_RES_CMD:
1113 		dev_dbg(dev->dev, "hbm: power gate isolation entry response received\n");
1114 		ret = mei_hbm_pg_enter_res(dev);
1115 		if (ret)
1116 			return ret;
1117 		break;
1118 
1119 	case MEI_PG_ISOLATION_EXIT_REQ_CMD:
1120 		dev_dbg(dev->dev, "hbm: power gate isolation exit request received\n");
1121 		ret = mei_hbm_pg_exit_res(dev);
1122 		if (ret)
1123 			return ret;
1124 		break;
1125 
1126 	case HOST_CLIENT_PROPERTIES_RES_CMD:
1127 		dev_dbg(dev->dev, "hbm: properties response: message received.\n");
1128 
1129 		dev->init_clients_timer = 0;
1130 
1131 		if (dev->dev_state != MEI_DEV_INIT_CLIENTS ||
1132 		    dev->hbm_state != MEI_HBM_CLIENT_PROPERTIES) {
1133 			dev_err(dev->dev, "hbm: properties response: state mismatch, [%d, %d]\n",
1134 				dev->dev_state, dev->hbm_state);
1135 			return -EPROTO;
1136 		}
1137 
1138 		props_res = (struct hbm_props_response *)mei_msg;
1139 
1140 		if (props_res->status) {
1141 			dev_err(dev->dev, "hbm: properties response: wrong status = %d %s\n",
1142 				props_res->status,
1143 				mei_hbm_status_str(props_res->status));
1144 			return -EPROTO;
1145 		}
1146 
1147 		mei_hbm_me_cl_add(dev, props_res);
1148 
1149 		/* request property for the next client */
1150 		if (mei_hbm_prop_req(dev, props_res->me_addr + 1))
1151 			return -EIO;
1152 
1153 		break;
1154 
1155 	case HOST_ENUM_RES_CMD:
1156 		dev_dbg(dev->dev, "hbm: enumeration response: message received\n");
1157 
1158 		dev->init_clients_timer = 0;
1159 
1160 		enum_res = (struct hbm_host_enum_response *) mei_msg;
1161 		BUILD_BUG_ON(sizeof(dev->me_clients_map)
1162 				< sizeof(enum_res->valid_addresses));
1163 		memcpy(dev->me_clients_map, enum_res->valid_addresses,
1164 				sizeof(enum_res->valid_addresses));
1165 
1166 		if (dev->dev_state != MEI_DEV_INIT_CLIENTS ||
1167 		    dev->hbm_state != MEI_HBM_ENUM_CLIENTS) {
1168 			dev_err(dev->dev, "hbm: enumeration response: state mismatch, [%d, %d]\n",
1169 				dev->dev_state, dev->hbm_state);
1170 			return -EPROTO;
1171 		}
1172 
1173 		dev->hbm_state = MEI_HBM_CLIENT_PROPERTIES;
1174 
1175 		/* first property request */
1176 		if (mei_hbm_prop_req(dev, 0))
1177 			return -EIO;
1178 
1179 		break;
1180 
1181 	case HOST_STOP_RES_CMD:
1182 		dev_dbg(dev->dev, "hbm: stop response: message received\n");
1183 
1184 		dev->init_clients_timer = 0;
1185 
1186 		if (dev->hbm_state != MEI_HBM_STOPPED) {
1187 			dev_err(dev->dev, "hbm: stop response: state mismatch, [%d, %d]\n",
1188 				dev->dev_state, dev->hbm_state);
1189 			return -EPROTO;
1190 		}
1191 
1192 		dev->dev_state = MEI_DEV_POWER_DOWN;
1193 		dev_info(dev->dev, "hbm: stop response: resetting.\n");
1194 		/* force the reset */
1195 		return -EPROTO;
1196 		break;
1197 
1198 	case CLIENT_DISCONNECT_REQ_CMD:
1199 		dev_dbg(dev->dev, "hbm: disconnect request: message received\n");
1200 
1201 		disconnect_req = (struct hbm_client_connect_request *)mei_msg;
1202 		mei_hbm_fw_disconnect_req(dev, disconnect_req);
1203 		break;
1204 
1205 	case ME_STOP_REQ_CMD:
1206 		dev_dbg(dev->dev, "hbm: stop request: message received\n");
1207 		dev->hbm_state = MEI_HBM_STOPPED;
1208 		if (mei_hbm_stop_req(dev)) {
1209 			dev_err(dev->dev, "hbm: stop request: failed to send stop request\n");
1210 			return -EIO;
1211 		}
1212 		break;
1213 
1214 	case MEI_HBM_ADD_CLIENT_REQ_CMD:
1215 		dev_dbg(dev->dev, "hbm: add client request received\n");
1216 		/*
1217 		 * after the host receives the enum_resp
1218 		 * message clients may be added or removed
1219 		 */
1220 		if (dev->hbm_state <= MEI_HBM_ENUM_CLIENTS ||
1221 		    dev->hbm_state >= MEI_HBM_STOPPED) {
1222 			dev_err(dev->dev, "hbm: add client: state mismatch, [%d, %d]\n",
1223 				dev->dev_state, dev->hbm_state);
1224 			return -EPROTO;
1225 		}
1226 		add_cl_req = (struct hbm_add_client_request *)mei_msg;
1227 		ret = mei_hbm_fw_add_cl_req(dev, add_cl_req);
1228 		if (ret) {
1229 			dev_err(dev->dev, "hbm: add client: failed to send response %d\n",
1230 				ret);
1231 			return -EIO;
1232 		}
1233 		dev_dbg(dev->dev, "hbm: add client request processed\n");
1234 		break;
1235 
1236 	case MEI_HBM_NOTIFY_RES_CMD:
1237 		dev_dbg(dev->dev, "hbm: notify response received\n");
1238 		mei_hbm_cl_res(dev, cl_cmd, notify_res_to_fop(cl_cmd));
1239 		break;
1240 
1241 	case MEI_HBM_NOTIFICATION_CMD:
1242 		dev_dbg(dev->dev, "hbm: notification\n");
1243 		mei_hbm_cl_notify(dev, cl_cmd);
1244 		break;
1245 
1246 	default:
1247 		BUG();
1248 		break;
1249 
1250 	}
1251 	return 0;
1252 }
1253 
1254