xref: /openbmc/linux/drivers/misc/mei/hbm.c (revision bc5aa3a0)
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  * @len: buffer length
165  *
166  * Return: 0 on success, <0 on failure.
167  */
168 static inline
169 int mei_hbm_cl_write(struct mei_device *dev, struct mei_cl *cl,
170 		     u8 hbm_cmd, u8 *buf, size_t len)
171 {
172 	struct mei_msg_hdr mei_hdr;
173 
174 	mei_hbm_hdr(&mei_hdr, len);
175 	mei_hbm_cl_hdr(cl, hbm_cmd, buf, len);
176 
177 	return mei_write_message(dev, &mei_hdr, buf);
178 }
179 
180 /**
181  * mei_hbm_cl_addr_equal - check if the client's and
182  *	the message address match
183  *
184  * @cl: client
185  * @cmd: hbm client message
186  *
187  * Return: true if addresses are the same
188  */
189 static inline
190 bool mei_hbm_cl_addr_equal(struct mei_cl *cl, struct mei_hbm_cl_cmd *cmd)
191 {
192 	return  mei_cl_host_addr(cl) == cmd->host_addr &&
193 		mei_cl_me_id(cl) == cmd->me_addr;
194 }
195 
196 /**
197  * mei_hbm_cl_find_by_cmd - find recipient client
198  *
199  * @dev: the device structure
200  * @buf: a buffer with hbm cl command
201  *
202  * Return: the recipient client or NULL if not found
203  */
204 static inline
205 struct mei_cl *mei_hbm_cl_find_by_cmd(struct mei_device *dev, void *buf)
206 {
207 	struct mei_hbm_cl_cmd *cmd = (struct mei_hbm_cl_cmd *)buf;
208 	struct mei_cl *cl;
209 
210 	list_for_each_entry(cl, &dev->file_list, link)
211 		if (mei_hbm_cl_addr_equal(cl, cmd))
212 			return cl;
213 	return NULL;
214 }
215 
216 
217 /**
218  * mei_hbm_start_wait - wait for start response message.
219  *
220  * @dev: the device structure
221  *
222  * Return: 0 on success and < 0 on failure
223  */
224 int mei_hbm_start_wait(struct mei_device *dev)
225 {
226 	int ret;
227 
228 	if (dev->hbm_state > MEI_HBM_STARTING)
229 		return 0;
230 
231 	mutex_unlock(&dev->device_lock);
232 	ret = wait_event_timeout(dev->wait_hbm_start,
233 			dev->hbm_state != MEI_HBM_STARTING,
234 			mei_secs_to_jiffies(MEI_HBM_TIMEOUT));
235 	mutex_lock(&dev->device_lock);
236 
237 	if (ret == 0 && (dev->hbm_state <= MEI_HBM_STARTING)) {
238 		dev->hbm_state = MEI_HBM_IDLE;
239 		dev_err(dev->dev, "waiting for mei start failed\n");
240 		return -ETIME;
241 	}
242 	return 0;
243 }
244 
245 /**
246  * mei_hbm_start_req - sends start request message.
247  *
248  * @dev: the device structure
249  *
250  * Return: 0 on success and < 0 on failure
251  */
252 int mei_hbm_start_req(struct mei_device *dev)
253 {
254 	struct mei_msg_hdr mei_hdr;
255 	struct hbm_host_version_request start_req;
256 	const size_t len = sizeof(struct hbm_host_version_request);
257 	int ret;
258 
259 	mei_hbm_reset(dev);
260 
261 	mei_hbm_hdr(&mei_hdr, len);
262 
263 	/* host start message */
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, &start_req);
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;
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 	memset(&enum_req, 0, len);
300 	enum_req.hbm_cmd = HOST_ENUM_REQ_CMD;
301 	enum_req.flags |= dev->hbm_f_dc_supported ?
302 			  MEI_HBM_ENUM_F_ALLOW_ADD : 0;
303 	enum_req.flags |= dev->hbm_f_ie_supported ?
304 			  MEI_HBM_ENUM_F_IMMEDIATE_ENUM : 0;
305 
306 	ret = mei_write_message(dev, &mei_hdr, &enum_req);
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;
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 	mei_hbm_hdr(&mei_hdr, len);
368 
369 	memset(&resp, 0, sizeof(struct hbm_add_client_response));
370 	resp.hbm_cmd = MEI_HBM_ADD_CLIENT_RES_CMD;
371 	resp.me_addr = addr;
372 	resp.status  = status;
373 
374 	ret = mei_write_message(dev, &mei_hdr, &resp);
375 	if (ret)
376 		dev_err(dev->dev, "add client response write failed: ret = %d\n",
377 			ret);
378 	return ret;
379 }
380 
381 /**
382  * mei_hbm_fw_add_cl_req - request from the fw to add a client
383  *
384  * @dev: the device structure
385  * @req: add client request
386  *
387  * Return: 0 on success and < 0 on failure
388  */
389 static int mei_hbm_fw_add_cl_req(struct mei_device *dev,
390 			      struct hbm_add_client_request *req)
391 {
392 	int ret;
393 	u8 status = MEI_HBMS_SUCCESS;
394 
395 	BUILD_BUG_ON(sizeof(struct hbm_add_client_request) !=
396 			sizeof(struct hbm_props_response));
397 
398 	ret = mei_hbm_me_cl_add(dev, (struct hbm_props_response *)req);
399 	if (ret)
400 		status = !MEI_HBMS_SUCCESS;
401 
402 	if (dev->dev_state == MEI_DEV_ENABLED)
403 		schedule_work(&dev->bus_rescan_work);
404 
405 	return mei_hbm_add_cl_resp(dev, req->me_addr, status);
406 }
407 
408 /**
409  * mei_hbm_cl_notify_req - send notification request
410  *
411  * @dev: the device structure
412  * @cl: a client to disconnect from
413  * @start: true for start false for stop
414  *
415  * Return: 0 on success and -EIO on write failure
416  */
417 int mei_hbm_cl_notify_req(struct mei_device *dev,
418 			  struct mei_cl *cl, u8 start)
419 {
420 
421 	struct mei_msg_hdr mei_hdr;
422 	struct hbm_notification_request req;
423 	const size_t len = sizeof(struct hbm_notification_request);
424 	int ret;
425 
426 	mei_hbm_hdr(&mei_hdr, len);
427 	mei_hbm_cl_hdr(cl, MEI_HBM_NOTIFY_REQ_CMD, &req, len);
428 
429 	req.start = start;
430 
431 	ret = mei_write_message(dev, &mei_hdr, &req);
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  * @start_idx: client index to start search
528  *
529  * Return: 0 on success and < 0 on failure
530  */
531 static int mei_hbm_prop_req(struct mei_device *dev, unsigned long start_idx)
532 {
533 	struct mei_msg_hdr mei_hdr;
534 	struct hbm_props_request prop_req;
535 	const size_t len = sizeof(struct hbm_props_request);
536 	unsigned long addr;
537 	int ret;
538 
539 	addr = find_next_bit(dev->me_clients_map, MEI_CLIENTS_MAX, start_idx);
540 
541 	/* We got all client properties */
542 	if (addr == MEI_CLIENTS_MAX) {
543 		dev->hbm_state = MEI_HBM_STARTED;
544 		mei_host_client_init(dev);
545 
546 		return 0;
547 	}
548 
549 	mei_hbm_hdr(&mei_hdr, len);
550 
551 	memset(&prop_req, 0, sizeof(struct hbm_props_request));
552 
553 	prop_req.hbm_cmd = HOST_CLIENT_PROPERTIES_REQ_CMD;
554 	prop_req.me_addr = addr;
555 
556 	ret = mei_write_message(dev, &mei_hdr, &prop_req);
557 	if (ret) {
558 		dev_err(dev->dev, "properties request write failed: ret = %d\n",
559 			ret);
560 		return ret;
561 	}
562 
563 	dev->init_clients_timer = MEI_CLIENTS_INIT_TIMEOUT;
564 
565 	return 0;
566 }
567 
568 /**
569  * mei_hbm_pg - sends pg command
570  *
571  * @dev: the device structure
572  * @pg_cmd: the pg command code
573  *
574  * Return: -EIO on write failure
575  *         -EOPNOTSUPP if the operation is not supported by the protocol
576  */
577 int mei_hbm_pg(struct mei_device *dev, u8 pg_cmd)
578 {
579 	struct mei_msg_hdr mei_hdr;
580 	struct hbm_power_gate req;
581 	const size_t len = sizeof(struct hbm_power_gate);
582 	int ret;
583 
584 	if (!dev->hbm_f_pg_supported)
585 		return -EOPNOTSUPP;
586 
587 	mei_hbm_hdr(&mei_hdr, len);
588 
589 	memset(&req, 0, len);
590 	req.hbm_cmd = pg_cmd;
591 
592 	ret = mei_write_message(dev, &mei_hdr, &req);
593 	if (ret)
594 		dev_err(dev->dev, "power gate command write failed.\n");
595 	return ret;
596 }
597 EXPORT_SYMBOL_GPL(mei_hbm_pg);
598 
599 /**
600  * mei_hbm_stop_req - send stop request message
601  *
602  * @dev: mei device
603  *
604  * Return: -EIO on write failure
605  */
606 static int mei_hbm_stop_req(struct mei_device *dev)
607 {
608 	struct mei_msg_hdr mei_hdr;
609 	struct hbm_host_stop_request req;
610 	const size_t len = sizeof(struct hbm_host_stop_request);
611 
612 	mei_hbm_hdr(&mei_hdr, len);
613 
614 	memset(&req, 0, len);
615 	req.hbm_cmd = HOST_STOP_REQ_CMD;
616 	req.reason = DRIVER_STOP_REQUEST;
617 
618 	return mei_write_message(dev, &mei_hdr, &req);
619 }
620 
621 /**
622  * mei_hbm_cl_flow_control_req - sends flow control request.
623  *
624  * @dev: the device structure
625  * @cl: client info
626  *
627  * Return: -EIO on write failure
628  */
629 int mei_hbm_cl_flow_control_req(struct mei_device *dev, struct mei_cl *cl)
630 {
631 	const size_t len = sizeof(struct hbm_flow_control);
632 	u8 buf[len];
633 
634 	cl_dbg(dev, cl, "sending flow control\n");
635 	return mei_hbm_cl_write(dev, cl, MEI_FLOW_CONTROL_CMD, buf, len);
636 }
637 
638 /**
639  * mei_hbm_add_single_flow_creds - adds single buffer credentials.
640  *
641  * @dev: the device structure
642  * @flow: flow control.
643  *
644  * Return: 0 on success, < 0 otherwise
645  */
646 static int mei_hbm_add_single_flow_creds(struct mei_device *dev,
647 				  struct hbm_flow_control *flow)
648 {
649 	struct mei_me_client *me_cl;
650 	int rets;
651 
652 	me_cl = mei_me_cl_by_id(dev, flow->me_addr);
653 	if (!me_cl) {
654 		dev_err(dev->dev, "no such me client %d\n",
655 			flow->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->mei_flow_ctrl_creds++;
665 	dev_dbg(dev->dev, "recv flow ctrl msg ME %d (single) creds = %d.\n",
666 	    flow->me_addr, me_cl->mei_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  * @flow_control: flow control response bus message
679  */
680 static void mei_hbm_cl_flow_control_res(struct mei_device *dev,
681 					struct hbm_flow_control *flow_control)
682 {
683 	struct mei_cl *cl;
684 
685 	if (!flow_control->host_addr) {
686 		/* single receive buffer */
687 		mei_hbm_add_single_flow_creds(dev, flow_control);
688 		return;
689 	}
690 
691 	cl = mei_hbm_cl_find_by_cmd(dev, flow_control);
692 	if (cl) {
693 		cl->mei_flow_ctrl_creds++;
694 		cl_dbg(dev, cl, "flow control creds = %d.\n",
695 				cl->mei_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_io_cb_init(cl, MEI_FOP_DISCONNECT_RSP, NULL);
875 		if (!cb)
876 			return -ENOMEM;
877 		list_add_tail(&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 	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 *flow_control;
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 		flow_control = (struct hbm_flow_control *) mei_msg;
1106 		mei_hbm_cl_flow_control_res(dev, flow_control);
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