xref: /openbmc/linux/drivers/misc/mei/hbm.c (revision 93f5715e)
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_write_message - wrapper for sending hbm messages.
100  *
101  * @dev: mei device
102  * @hdr: mei header
103  * @data: payload
104  */
105 static inline int mei_hbm_write_message(struct mei_device *dev,
106 					struct mei_msg_hdr *hdr,
107 					const void *data)
108 {
109 	return mei_write_message(dev, hdr, sizeof(*hdr), data, hdr->length);
110 }
111 
112 /**
113  * mei_hbm_idle - set hbm to idle state
114  *
115  * @dev: the device structure
116  */
117 void mei_hbm_idle(struct mei_device *dev)
118 {
119 	dev->init_clients_timer = 0;
120 	dev->hbm_state = MEI_HBM_IDLE;
121 }
122 
123 /**
124  * mei_hbm_reset - reset hbm counters and book keeping data structurs
125  *
126  * @dev: the device structure
127  */
128 void mei_hbm_reset(struct mei_device *dev)
129 {
130 	mei_me_cl_rm_all(dev);
131 
132 	mei_hbm_idle(dev);
133 }
134 
135 /**
136  * mei_hbm_hdr - construct hbm header
137  *
138  * @hdr: hbm header
139  * @length: payload length
140  */
141 
142 static inline void mei_hbm_hdr(struct mei_msg_hdr *hdr, size_t length)
143 {
144 	hdr->host_addr = 0;
145 	hdr->me_addr = 0;
146 	hdr->length = length;
147 	hdr->msg_complete = 1;
148 	hdr->dma_ring = 0;
149 	hdr->reserved = 0;
150 	hdr->internal = 0;
151 }
152 
153 /**
154  * mei_hbm_cl_hdr - construct client hbm header
155  *
156  * @cl: client
157  * @hbm_cmd: host bus message command
158  * @buf: buffer for cl header
159  * @len: buffer length
160  */
161 static inline
162 void mei_hbm_cl_hdr(struct mei_cl *cl, u8 hbm_cmd, void *buf, size_t len)
163 {
164 	struct mei_hbm_cl_cmd *cmd = buf;
165 
166 	memset(cmd, 0, len);
167 
168 	cmd->hbm_cmd = hbm_cmd;
169 	cmd->host_addr = mei_cl_host_addr(cl);
170 	cmd->me_addr = mei_cl_me_id(cl);
171 }
172 
173 /**
174  * mei_hbm_cl_write - write simple hbm client message
175  *
176  * @dev: the device structure
177  * @cl: client
178  * @hbm_cmd: host bus message command
179  * @buf: message buffer
180  * @len: buffer length
181  *
182  * Return: 0 on success, <0 on failure.
183  */
184 static inline int mei_hbm_cl_write(struct mei_device *dev, struct mei_cl *cl,
185 				   u8 hbm_cmd, void *buf, size_t len)
186 {
187 	struct mei_msg_hdr mei_hdr;
188 
189 	mei_hbm_hdr(&mei_hdr, len);
190 	mei_hbm_cl_hdr(cl, hbm_cmd, buf, len);
191 
192 	return mei_hbm_write_message(dev, &mei_hdr, buf);
193 }
194 
195 /**
196  * mei_hbm_cl_addr_equal - check if the client's and
197  *	the message address match
198  *
199  * @cl: client
200  * @cmd: hbm client message
201  *
202  * Return: true if addresses are the same
203  */
204 static inline
205 bool mei_hbm_cl_addr_equal(struct mei_cl *cl, struct mei_hbm_cl_cmd *cmd)
206 {
207 	return  mei_cl_host_addr(cl) == cmd->host_addr &&
208 		mei_cl_me_id(cl) == cmd->me_addr;
209 }
210 
211 /**
212  * mei_hbm_cl_find_by_cmd - find recipient client
213  *
214  * @dev: the device structure
215  * @buf: a buffer with hbm cl command
216  *
217  * Return: the recipient client or NULL if not found
218  */
219 static inline
220 struct mei_cl *mei_hbm_cl_find_by_cmd(struct mei_device *dev, void *buf)
221 {
222 	struct mei_hbm_cl_cmd *cmd = (struct mei_hbm_cl_cmd *)buf;
223 	struct mei_cl *cl;
224 
225 	list_for_each_entry(cl, &dev->file_list, link)
226 		if (mei_hbm_cl_addr_equal(cl, cmd))
227 			return cl;
228 	return NULL;
229 }
230 
231 
232 /**
233  * mei_hbm_start_wait - wait for start response message.
234  *
235  * @dev: the device structure
236  *
237  * Return: 0 on success and < 0 on failure
238  */
239 int mei_hbm_start_wait(struct mei_device *dev)
240 {
241 	int ret;
242 
243 	if (dev->hbm_state > MEI_HBM_STARTING)
244 		return 0;
245 
246 	mutex_unlock(&dev->device_lock);
247 	ret = wait_event_timeout(dev->wait_hbm_start,
248 			dev->hbm_state != MEI_HBM_STARTING,
249 			mei_secs_to_jiffies(MEI_HBM_TIMEOUT));
250 	mutex_lock(&dev->device_lock);
251 
252 	if (ret == 0 && (dev->hbm_state <= MEI_HBM_STARTING)) {
253 		dev->hbm_state = MEI_HBM_IDLE;
254 		dev_err(dev->dev, "waiting for mei start failed\n");
255 		return -ETIME;
256 	}
257 	return 0;
258 }
259 
260 /**
261  * mei_hbm_start_req - sends start request message.
262  *
263  * @dev: the device structure
264  *
265  * Return: 0 on success and < 0 on failure
266  */
267 int mei_hbm_start_req(struct mei_device *dev)
268 {
269 	struct mei_msg_hdr mei_hdr;
270 	struct hbm_host_version_request start_req;
271 	const size_t len = sizeof(struct hbm_host_version_request);
272 	int ret;
273 
274 	mei_hbm_reset(dev);
275 
276 	mei_hbm_hdr(&mei_hdr, len);
277 
278 	/* host start message */
279 	memset(&start_req, 0, len);
280 	start_req.hbm_cmd = HOST_START_REQ_CMD;
281 	start_req.host_version.major_version = HBM_MAJOR_VERSION;
282 	start_req.host_version.minor_version = HBM_MINOR_VERSION;
283 
284 	dev->hbm_state = MEI_HBM_IDLE;
285 	ret = mei_hbm_write_message(dev, &mei_hdr, &start_req);
286 	if (ret) {
287 		dev_err(dev->dev, "version message write failed: ret = %d\n",
288 			ret);
289 		return ret;
290 	}
291 
292 	dev->hbm_state = MEI_HBM_STARTING;
293 	dev->init_clients_timer = MEI_CLIENTS_INIT_TIMEOUT;
294 	mei_schedule_stall_timer(dev);
295 	return 0;
296 }
297 
298 /**
299  * mei_hbm_enum_clients_req - sends enumeration client request message.
300  *
301  * @dev: the device structure
302  *
303  * Return: 0 on success and < 0 on failure
304  */
305 static int mei_hbm_enum_clients_req(struct mei_device *dev)
306 {
307 	struct mei_msg_hdr mei_hdr;
308 	struct hbm_host_enum_request enum_req;
309 	const size_t len = sizeof(struct hbm_host_enum_request);
310 	int ret;
311 
312 	/* enumerate clients */
313 	mei_hbm_hdr(&mei_hdr, len);
314 
315 	memset(&enum_req, 0, len);
316 	enum_req.hbm_cmd = HOST_ENUM_REQ_CMD;
317 	enum_req.flags |= dev->hbm_f_dc_supported ?
318 			  MEI_HBM_ENUM_F_ALLOW_ADD : 0;
319 	enum_req.flags |= dev->hbm_f_ie_supported ?
320 			  MEI_HBM_ENUM_F_IMMEDIATE_ENUM : 0;
321 
322 	ret = mei_hbm_write_message(dev, &mei_hdr, &enum_req);
323 	if (ret) {
324 		dev_err(dev->dev, "enumeration request write failed: ret = %d.\n",
325 			ret);
326 		return ret;
327 	}
328 	dev->hbm_state = MEI_HBM_ENUM_CLIENTS;
329 	dev->init_clients_timer = MEI_CLIENTS_INIT_TIMEOUT;
330 	mei_schedule_stall_timer(dev);
331 	return 0;
332 }
333 
334 /**
335  * mei_hbm_me_cl_add - add new me client to the list
336  *
337  * @dev: the device structure
338  * @res: hbm property response
339  *
340  * Return: 0 on success and -ENOMEM on allocation failure
341  */
342 
343 static int mei_hbm_me_cl_add(struct mei_device *dev,
344 			     struct hbm_props_response *res)
345 {
346 	struct mei_me_client *me_cl;
347 	const uuid_le *uuid = &res->client_properties.protocol_name;
348 
349 	mei_me_cl_rm_by_uuid(dev, uuid);
350 
351 	me_cl = kzalloc(sizeof(struct mei_me_client), GFP_KERNEL);
352 	if (!me_cl)
353 		return -ENOMEM;
354 
355 	mei_me_cl_init(me_cl);
356 
357 	me_cl->props = res->client_properties;
358 	me_cl->client_id = res->me_addr;
359 	me_cl->tx_flow_ctrl_creds = 0;
360 
361 	mei_me_cl_add(dev, me_cl);
362 
363 	return 0;
364 }
365 
366 /**
367  * mei_hbm_add_cl_resp - send response to fw on client add request
368  *
369  * @dev: the device structure
370  * @addr: me address
371  * @status: response status
372  *
373  * Return: 0 on success and < 0 on failure
374  */
375 static int mei_hbm_add_cl_resp(struct mei_device *dev, u8 addr, u8 status)
376 {
377 	struct mei_msg_hdr mei_hdr;
378 	struct hbm_add_client_response resp;
379 	const size_t len = sizeof(struct hbm_add_client_response);
380 	int ret;
381 
382 	dev_dbg(dev->dev, "adding client response\n");
383 
384 	mei_hbm_hdr(&mei_hdr, len);
385 
386 	memset(&resp, 0, sizeof(struct hbm_add_client_response));
387 	resp.hbm_cmd = MEI_HBM_ADD_CLIENT_RES_CMD;
388 	resp.me_addr = addr;
389 	resp.status  = status;
390 
391 	ret = mei_hbm_write_message(dev, &mei_hdr, &resp);
392 	if (ret)
393 		dev_err(dev->dev, "add client response write failed: ret = %d\n",
394 			ret);
395 	return ret;
396 }
397 
398 /**
399  * mei_hbm_fw_add_cl_req - request from the fw to add a client
400  *
401  * @dev: the device structure
402  * @req: add client request
403  *
404  * Return: 0 on success and < 0 on failure
405  */
406 static int mei_hbm_fw_add_cl_req(struct mei_device *dev,
407 			      struct hbm_add_client_request *req)
408 {
409 	int ret;
410 	u8 status = MEI_HBMS_SUCCESS;
411 
412 	BUILD_BUG_ON(sizeof(struct hbm_add_client_request) !=
413 			sizeof(struct hbm_props_response));
414 
415 	ret = mei_hbm_me_cl_add(dev, (struct hbm_props_response *)req);
416 	if (ret)
417 		status = !MEI_HBMS_SUCCESS;
418 
419 	if (dev->dev_state == MEI_DEV_ENABLED)
420 		schedule_work(&dev->bus_rescan_work);
421 
422 	return mei_hbm_add_cl_resp(dev, req->me_addr, status);
423 }
424 
425 /**
426  * mei_hbm_cl_notify_req - send notification request
427  *
428  * @dev: the device structure
429  * @cl: a client to disconnect from
430  * @start: true for start false for stop
431  *
432  * Return: 0 on success and -EIO on write failure
433  */
434 int mei_hbm_cl_notify_req(struct mei_device *dev,
435 			  struct mei_cl *cl, u8 start)
436 {
437 
438 	struct mei_msg_hdr mei_hdr;
439 	struct hbm_notification_request req;
440 	const size_t len = sizeof(struct hbm_notification_request);
441 	int ret;
442 
443 	mei_hbm_hdr(&mei_hdr, len);
444 	mei_hbm_cl_hdr(cl, MEI_HBM_NOTIFY_REQ_CMD, &req, len);
445 
446 	req.start = start;
447 
448 	ret = mei_hbm_write_message(dev, &mei_hdr, &req);
449 	if (ret)
450 		dev_err(dev->dev, "notify request failed: ret = %d\n", ret);
451 
452 	return ret;
453 }
454 
455 /**
456  *  notify_res_to_fop - convert notification response to the proper
457  *      notification FOP
458  *
459  * @cmd: client notification start response command
460  *
461  * Return:  MEI_FOP_NOTIFY_START or MEI_FOP_NOTIFY_STOP;
462  */
463 static inline enum mei_cb_file_ops notify_res_to_fop(struct mei_hbm_cl_cmd *cmd)
464 {
465 	struct hbm_notification_response *rs =
466 		(struct hbm_notification_response *)cmd;
467 
468 	return mei_cl_notify_req2fop(rs->start);
469 }
470 
471 /**
472  * mei_hbm_cl_notify_start_res - update the client state according
473  *       notify start response
474  *
475  * @dev: the device structure
476  * @cl: mei host client
477  * @cmd: client notification start response command
478  */
479 static void mei_hbm_cl_notify_start_res(struct mei_device *dev,
480 					struct mei_cl *cl,
481 					struct mei_hbm_cl_cmd *cmd)
482 {
483 	struct hbm_notification_response *rs =
484 		(struct hbm_notification_response *)cmd;
485 
486 	cl_dbg(dev, cl, "hbm: notify start response status=%d\n", rs->status);
487 
488 	if (rs->status == MEI_HBMS_SUCCESS ||
489 	    rs->status == MEI_HBMS_ALREADY_STARTED) {
490 		cl->notify_en = true;
491 		cl->status = 0;
492 	} else {
493 		cl->status = -EINVAL;
494 	}
495 }
496 
497 /**
498  * mei_hbm_cl_notify_stop_res - update the client state according
499  *       notify stop response
500  *
501  * @dev: the device structure
502  * @cl: mei host client
503  * @cmd: client notification stop response command
504  */
505 static void mei_hbm_cl_notify_stop_res(struct mei_device *dev,
506 				       struct mei_cl *cl,
507 				       struct mei_hbm_cl_cmd *cmd)
508 {
509 	struct hbm_notification_response *rs =
510 		(struct hbm_notification_response *)cmd;
511 
512 	cl_dbg(dev, cl, "hbm: notify stop response status=%d\n", rs->status);
513 
514 	if (rs->status == MEI_HBMS_SUCCESS ||
515 	    rs->status == MEI_HBMS_NOT_STARTED) {
516 		cl->notify_en = false;
517 		cl->status = 0;
518 	} else {
519 		/* TODO: spec is not clear yet about other possible issues */
520 		cl->status = -EINVAL;
521 	}
522 }
523 
524 /**
525  * mei_hbm_cl_notify - signal notification event
526  *
527  * @dev: the device structure
528  * @cmd: notification client message
529  */
530 static void mei_hbm_cl_notify(struct mei_device *dev,
531 			      struct mei_hbm_cl_cmd *cmd)
532 {
533 	struct mei_cl *cl;
534 
535 	cl = mei_hbm_cl_find_by_cmd(dev, cmd);
536 	if (cl)
537 		mei_cl_notify(cl);
538 }
539 
540 /**
541  * mei_hbm_prop_req - request property for a single client
542  *
543  * @dev: the device structure
544  * @start_idx: client index to start search
545  *
546  * Return: 0 on success and < 0 on failure
547  */
548 static int mei_hbm_prop_req(struct mei_device *dev, unsigned long start_idx)
549 {
550 	struct mei_msg_hdr mei_hdr;
551 	struct hbm_props_request prop_req;
552 	const size_t len = sizeof(struct hbm_props_request);
553 	unsigned long addr;
554 	int ret;
555 
556 	addr = find_next_bit(dev->me_clients_map, MEI_CLIENTS_MAX, start_idx);
557 
558 	/* We got all client properties */
559 	if (addr == MEI_CLIENTS_MAX) {
560 		dev->hbm_state = MEI_HBM_STARTED;
561 		mei_host_client_init(dev);
562 
563 		return 0;
564 	}
565 
566 	mei_hbm_hdr(&mei_hdr, len);
567 
568 	memset(&prop_req, 0, sizeof(struct hbm_props_request));
569 
570 	prop_req.hbm_cmd = HOST_CLIENT_PROPERTIES_REQ_CMD;
571 	prop_req.me_addr = addr;
572 
573 	ret = mei_hbm_write_message(dev, &mei_hdr, &prop_req);
574 	if (ret) {
575 		dev_err(dev->dev, "properties request write failed: ret = %d\n",
576 			ret);
577 		return ret;
578 	}
579 
580 	dev->init_clients_timer = MEI_CLIENTS_INIT_TIMEOUT;
581 	mei_schedule_stall_timer(dev);
582 
583 	return 0;
584 }
585 
586 /**
587  * mei_hbm_pg - sends pg command
588  *
589  * @dev: the device structure
590  * @pg_cmd: the pg command code
591  *
592  * Return: -EIO on write failure
593  *         -EOPNOTSUPP if the operation is not supported by the protocol
594  */
595 int mei_hbm_pg(struct mei_device *dev, u8 pg_cmd)
596 {
597 	struct mei_msg_hdr mei_hdr;
598 	struct hbm_power_gate req;
599 	const size_t len = sizeof(struct hbm_power_gate);
600 	int ret;
601 
602 	if (!dev->hbm_f_pg_supported)
603 		return -EOPNOTSUPP;
604 
605 	mei_hbm_hdr(&mei_hdr, len);
606 
607 	memset(&req, 0, len);
608 	req.hbm_cmd = pg_cmd;
609 
610 	ret = mei_hbm_write_message(dev, &mei_hdr, &req);
611 	if (ret)
612 		dev_err(dev->dev, "power gate command write failed.\n");
613 	return ret;
614 }
615 EXPORT_SYMBOL_GPL(mei_hbm_pg);
616 
617 /**
618  * mei_hbm_stop_req - send stop request message
619  *
620  * @dev: mei device
621  *
622  * Return: -EIO on write failure
623  */
624 static int mei_hbm_stop_req(struct mei_device *dev)
625 {
626 	struct mei_msg_hdr mei_hdr;
627 	struct hbm_host_stop_request req;
628 	const size_t len = sizeof(struct hbm_host_stop_request);
629 
630 	mei_hbm_hdr(&mei_hdr, len);
631 
632 	memset(&req, 0, len);
633 	req.hbm_cmd = HOST_STOP_REQ_CMD;
634 	req.reason = DRIVER_STOP_REQUEST;
635 
636 	return mei_hbm_write_message(dev, &mei_hdr, &req);
637 }
638 
639 /**
640  * mei_hbm_cl_flow_control_req - sends flow control request.
641  *
642  * @dev: the device structure
643  * @cl: client info
644  *
645  * Return: -EIO on write failure
646  */
647 int mei_hbm_cl_flow_control_req(struct mei_device *dev, struct mei_cl *cl)
648 {
649 	struct hbm_flow_control req;
650 
651 	cl_dbg(dev, cl, "sending flow control\n");
652 	return mei_hbm_cl_write(dev, cl, MEI_FLOW_CONTROL_CMD,
653 				&req, sizeof(req));
654 }
655 
656 /**
657  * mei_hbm_add_single_tx_flow_ctrl_creds - adds single buffer credentials.
658  *
659  * @dev: the device structure
660  * @fctrl: flow control response bus message
661  *
662  * Return: 0 on success, < 0 otherwise
663  */
664 static int mei_hbm_add_single_tx_flow_ctrl_creds(struct mei_device *dev,
665 						 struct hbm_flow_control *fctrl)
666 {
667 	struct mei_me_client *me_cl;
668 	int rets;
669 
670 	me_cl = mei_me_cl_by_id(dev, fctrl->me_addr);
671 	if (!me_cl) {
672 		dev_err(dev->dev, "no such me client %d\n", fctrl->me_addr);
673 		return -ENOENT;
674 	}
675 
676 	if (WARN_ON(me_cl->props.single_recv_buf == 0)) {
677 		rets = -EINVAL;
678 		goto out;
679 	}
680 
681 	me_cl->tx_flow_ctrl_creds++;
682 	dev_dbg(dev->dev, "recv flow ctrl msg ME %d (single) creds = %d.\n",
683 		fctrl->me_addr, me_cl->tx_flow_ctrl_creds);
684 
685 	rets = 0;
686 out:
687 	mei_me_cl_put(me_cl);
688 	return rets;
689 }
690 
691 /**
692  * mei_hbm_cl_flow_control_res - flow control response from me
693  *
694  * @dev: the device structure
695  * @fctrl: flow control response bus message
696  */
697 static void mei_hbm_cl_tx_flow_ctrl_creds_res(struct mei_device *dev,
698 					       struct hbm_flow_control *fctrl)
699 {
700 	struct mei_cl *cl;
701 
702 	if (!fctrl->host_addr) {
703 		/* single receive buffer */
704 		mei_hbm_add_single_tx_flow_ctrl_creds(dev, fctrl);
705 		return;
706 	}
707 
708 	cl = mei_hbm_cl_find_by_cmd(dev, fctrl);
709 	if (cl) {
710 		cl->tx_flow_ctrl_creds++;
711 		cl_dbg(dev, cl, "flow control creds = %d.\n",
712 				cl->tx_flow_ctrl_creds);
713 	}
714 }
715 
716 
717 /**
718  * mei_hbm_cl_disconnect_req - sends disconnect message to fw.
719  *
720  * @dev: the device structure
721  * @cl: a client to disconnect from
722  *
723  * Return: -EIO on write failure
724  */
725 int mei_hbm_cl_disconnect_req(struct mei_device *dev, struct mei_cl *cl)
726 {
727 	struct hbm_client_connect_request req;
728 
729 	return mei_hbm_cl_write(dev, cl, CLIENT_DISCONNECT_REQ_CMD,
730 				&req, sizeof(req));
731 }
732 
733 /**
734  * mei_hbm_cl_disconnect_rsp - sends disconnect respose to the FW
735  *
736  * @dev: the device structure
737  * @cl: a client to disconnect from
738  *
739  * Return: -EIO on write failure
740  */
741 int mei_hbm_cl_disconnect_rsp(struct mei_device *dev, struct mei_cl *cl)
742 {
743 	struct hbm_client_connect_response resp;
744 
745 	return mei_hbm_cl_write(dev, cl, CLIENT_DISCONNECT_RES_CMD,
746 				&resp, sizeof(resp));
747 }
748 
749 /**
750  * mei_hbm_cl_disconnect_res - update the client state according
751  *       disconnect response
752  *
753  * @dev: the device structure
754  * @cl: mei host client
755  * @cmd: disconnect client response host bus message
756  */
757 static void mei_hbm_cl_disconnect_res(struct mei_device *dev, struct mei_cl *cl,
758 				      struct mei_hbm_cl_cmd *cmd)
759 {
760 	struct hbm_client_connect_response *rs =
761 		(struct hbm_client_connect_response *)cmd;
762 
763 	cl_dbg(dev, cl, "hbm: disconnect response status=%d\n", rs->status);
764 
765 	if (rs->status == MEI_CL_DISCONN_SUCCESS)
766 		cl->state = MEI_FILE_DISCONNECT_REPLY;
767 	cl->status = 0;
768 }
769 
770 /**
771  * mei_hbm_cl_connect_req - send connection request to specific me client
772  *
773  * @dev: the device structure
774  * @cl: a client to connect to
775  *
776  * Return: -EIO on write failure
777  */
778 int mei_hbm_cl_connect_req(struct mei_device *dev, struct mei_cl *cl)
779 {
780 	struct hbm_client_connect_request req;
781 
782 	return mei_hbm_cl_write(dev, cl, CLIENT_CONNECT_REQ_CMD,
783 				&req, sizeof(req));
784 }
785 
786 /**
787  * mei_hbm_cl_connect_res - update the client state according
788  *        connection response
789  *
790  * @dev: the device structure
791  * @cl: mei host client
792  * @cmd: connect client response host bus message
793  */
794 static void mei_hbm_cl_connect_res(struct mei_device *dev, struct mei_cl *cl,
795 				   struct mei_hbm_cl_cmd *cmd)
796 {
797 	struct hbm_client_connect_response *rs =
798 		(struct hbm_client_connect_response *)cmd;
799 
800 	cl_dbg(dev, cl, "hbm: connect response status=%s\n",
801 			mei_cl_conn_status_str(rs->status));
802 
803 	if (rs->status == MEI_CL_CONN_SUCCESS)
804 		cl->state = MEI_FILE_CONNECTED;
805 	else {
806 		cl->state = MEI_FILE_DISCONNECT_REPLY;
807 		if (rs->status == MEI_CL_CONN_NOT_FOUND) {
808 			mei_me_cl_del(dev, cl->me_cl);
809 			if (dev->dev_state == MEI_DEV_ENABLED)
810 				schedule_work(&dev->bus_rescan_work);
811 		}
812 	}
813 	cl->status = mei_cl_conn_status_to_errno(rs->status);
814 }
815 
816 /**
817  * mei_hbm_cl_res - process hbm response received on behalf
818  *         an client
819  *
820  * @dev: the device structure
821  * @rs:  hbm client message
822  * @fop_type: file operation type
823  */
824 static void mei_hbm_cl_res(struct mei_device *dev,
825 			   struct mei_hbm_cl_cmd *rs,
826 			   enum mei_cb_file_ops fop_type)
827 {
828 	struct mei_cl *cl;
829 	struct mei_cl_cb *cb, *next;
830 
831 	cl = NULL;
832 	list_for_each_entry_safe(cb, next, &dev->ctrl_rd_list, list) {
833 
834 		cl = cb->cl;
835 
836 		if (cb->fop_type != fop_type)
837 			continue;
838 
839 		if (mei_hbm_cl_addr_equal(cl, rs)) {
840 			list_del_init(&cb->list);
841 			break;
842 		}
843 	}
844 
845 	if (!cl)
846 		return;
847 
848 	switch (fop_type) {
849 	case MEI_FOP_CONNECT:
850 		mei_hbm_cl_connect_res(dev, cl, rs);
851 		break;
852 	case MEI_FOP_DISCONNECT:
853 		mei_hbm_cl_disconnect_res(dev, cl, rs);
854 		break;
855 	case MEI_FOP_NOTIFY_START:
856 		mei_hbm_cl_notify_start_res(dev, cl, rs);
857 		break;
858 	case MEI_FOP_NOTIFY_STOP:
859 		mei_hbm_cl_notify_stop_res(dev, cl, rs);
860 		break;
861 	default:
862 		return;
863 	}
864 
865 	cl->timer_count = 0;
866 	wake_up(&cl->wait);
867 }
868 
869 
870 /**
871  * mei_hbm_fw_disconnect_req - disconnect request initiated by ME firmware
872  *  host sends disconnect response
873  *
874  * @dev: the device structure.
875  * @disconnect_req: disconnect request bus message from the me
876  *
877  * Return: -ENOMEM on allocation failure
878  */
879 static int mei_hbm_fw_disconnect_req(struct mei_device *dev,
880 		struct hbm_client_connect_request *disconnect_req)
881 {
882 	struct mei_cl *cl;
883 	struct mei_cl_cb *cb;
884 
885 	cl = mei_hbm_cl_find_by_cmd(dev, disconnect_req);
886 	if (cl) {
887 		cl_warn(dev, cl, "fw disconnect request received\n");
888 		cl->state = MEI_FILE_DISCONNECTING;
889 		cl->timer_count = 0;
890 
891 		cb = mei_cl_enqueue_ctrl_wr_cb(cl, 0, MEI_FOP_DISCONNECT_RSP,
892 					       NULL);
893 		if (!cb)
894 			return -ENOMEM;
895 	}
896 	return 0;
897 }
898 
899 /**
900  * mei_hbm_pg_enter_res - PG enter response received
901  *
902  * @dev: the device structure.
903  *
904  * Return: 0 on success, -EPROTO on state mismatch
905  */
906 static int mei_hbm_pg_enter_res(struct mei_device *dev)
907 {
908 	if (mei_pg_state(dev) != MEI_PG_OFF ||
909 	    dev->pg_event != MEI_PG_EVENT_WAIT) {
910 		dev_err(dev->dev, "hbm: pg entry response: state mismatch [%s, %d]\n",
911 			mei_pg_state_str(mei_pg_state(dev)), dev->pg_event);
912 		return -EPROTO;
913 	}
914 
915 	dev->pg_event = MEI_PG_EVENT_RECEIVED;
916 	wake_up(&dev->wait_pg);
917 
918 	return 0;
919 }
920 
921 /**
922  * mei_hbm_pg_resume - process with PG resume
923  *
924  * @dev: the device structure.
925  */
926 void mei_hbm_pg_resume(struct mei_device *dev)
927 {
928 	pm_request_resume(dev->dev);
929 }
930 EXPORT_SYMBOL_GPL(mei_hbm_pg_resume);
931 
932 /**
933  * mei_hbm_pg_exit_res - PG exit response received
934  *
935  * @dev: the device structure.
936  *
937  * Return: 0 on success, -EPROTO on state mismatch
938  */
939 static int mei_hbm_pg_exit_res(struct mei_device *dev)
940 {
941 	if (mei_pg_state(dev) != MEI_PG_ON ||
942 	    (dev->pg_event != MEI_PG_EVENT_WAIT &&
943 	     dev->pg_event != MEI_PG_EVENT_IDLE)) {
944 		dev_err(dev->dev, "hbm: pg exit response: state mismatch [%s, %d]\n",
945 			mei_pg_state_str(mei_pg_state(dev)), dev->pg_event);
946 		return -EPROTO;
947 	}
948 
949 	switch (dev->pg_event) {
950 	case MEI_PG_EVENT_WAIT:
951 		dev->pg_event = MEI_PG_EVENT_RECEIVED;
952 		wake_up(&dev->wait_pg);
953 		break;
954 	case MEI_PG_EVENT_IDLE:
955 		/*
956 		* If the driver is not waiting on this then
957 		* this is HW initiated exit from PG.
958 		* Start runtime pm resume sequence to exit from PG.
959 		*/
960 		dev->pg_event = MEI_PG_EVENT_RECEIVED;
961 		mei_hbm_pg_resume(dev);
962 		break;
963 	default:
964 		WARN(1, "hbm: pg exit response: unexpected pg event = %d\n",
965 		     dev->pg_event);
966 		return -EPROTO;
967 	}
968 
969 	return 0;
970 }
971 
972 /**
973  * mei_hbm_config_features - check what hbm features and commands
974  *        are supported by the fw
975  *
976  * @dev: the device structure
977  */
978 static void mei_hbm_config_features(struct mei_device *dev)
979 {
980 	/* Power Gating Isolation Support */
981 	dev->hbm_f_pg_supported = 0;
982 	if (dev->version.major_version > HBM_MAJOR_VERSION_PGI)
983 		dev->hbm_f_pg_supported = 1;
984 
985 	if (dev->version.major_version == HBM_MAJOR_VERSION_PGI &&
986 	    dev->version.minor_version >= HBM_MINOR_VERSION_PGI)
987 		dev->hbm_f_pg_supported = 1;
988 
989 	if (dev->version.major_version >= HBM_MAJOR_VERSION_DC)
990 		dev->hbm_f_dc_supported = 1;
991 
992 	if (dev->version.major_version >= HBM_MAJOR_VERSION_IE)
993 		dev->hbm_f_ie_supported = 1;
994 
995 	/* disconnect on connect timeout instead of link reset */
996 	if (dev->version.major_version >= HBM_MAJOR_VERSION_DOT)
997 		dev->hbm_f_dot_supported = 1;
998 
999 	/* Notification Event Support */
1000 	if (dev->version.major_version >= HBM_MAJOR_VERSION_EV)
1001 		dev->hbm_f_ev_supported = 1;
1002 
1003 	/* Fixed Address Client Support */
1004 	if (dev->version.major_version >= HBM_MAJOR_VERSION_FA)
1005 		dev->hbm_f_fa_supported = 1;
1006 
1007 	/* OS ver message Support */
1008 	if (dev->version.major_version >= HBM_MAJOR_VERSION_OS)
1009 		dev->hbm_f_os_supported = 1;
1010 
1011 	/* DMA Ring Support */
1012 	if (dev->version.major_version > HBM_MAJOR_VERSION_DR ||
1013 	    (dev->version.major_version == HBM_MAJOR_VERSION_DR &&
1014 	     dev->version.minor_version >= HBM_MINOR_VERSION_DR))
1015 		dev->hbm_f_dr_supported = 1;
1016 }
1017 
1018 /**
1019  * mei_hbm_version_is_supported - checks whether the driver can
1020  *     support the hbm version of the device
1021  *
1022  * @dev: the device structure
1023  * Return: true if driver can support hbm version of the device
1024  */
1025 bool mei_hbm_version_is_supported(struct mei_device *dev)
1026 {
1027 	return	(dev->version.major_version < HBM_MAJOR_VERSION) ||
1028 		(dev->version.major_version == HBM_MAJOR_VERSION &&
1029 		 dev->version.minor_version <= HBM_MINOR_VERSION);
1030 }
1031 
1032 /**
1033  * mei_hbm_dispatch - bottom half read routine after ISR to
1034  * handle the read bus message cmd processing.
1035  *
1036  * @dev: the device structure
1037  * @hdr: header of bus message
1038  *
1039  * Return: 0 on success and < 0 on failure
1040  */
1041 int mei_hbm_dispatch(struct mei_device *dev, struct mei_msg_hdr *hdr)
1042 {
1043 	struct mei_bus_message *mei_msg;
1044 	struct hbm_host_version_response *version_res;
1045 	struct hbm_props_response *props_res;
1046 	struct hbm_host_enum_response *enum_res;
1047 	struct hbm_add_client_request *add_cl_req;
1048 	int ret;
1049 
1050 	struct mei_hbm_cl_cmd *cl_cmd;
1051 	struct hbm_client_connect_request *disconnect_req;
1052 	struct hbm_flow_control *fctrl;
1053 
1054 	/* read the message to our buffer */
1055 	BUG_ON(hdr->length >= sizeof(dev->rd_msg_buf));
1056 	mei_read_slots(dev, dev->rd_msg_buf, hdr->length);
1057 	mei_msg = (struct mei_bus_message *)dev->rd_msg_buf;
1058 	cl_cmd  = (struct mei_hbm_cl_cmd *)mei_msg;
1059 
1060 	/* ignore spurious message and prevent reset nesting
1061 	 * hbm is put to idle during system reset
1062 	 */
1063 	if (dev->hbm_state == MEI_HBM_IDLE) {
1064 		dev_dbg(dev->dev, "hbm: state is idle ignore spurious messages\n");
1065 		return 0;
1066 	}
1067 
1068 	switch (mei_msg->hbm_cmd) {
1069 	case HOST_START_RES_CMD:
1070 		dev_dbg(dev->dev, "hbm: start: response message received.\n");
1071 
1072 		dev->init_clients_timer = 0;
1073 
1074 		version_res = (struct hbm_host_version_response *)mei_msg;
1075 
1076 		dev_dbg(dev->dev, "HBM VERSION: DRIVER=%02d:%02d DEVICE=%02d:%02d\n",
1077 				HBM_MAJOR_VERSION, HBM_MINOR_VERSION,
1078 				version_res->me_max_version.major_version,
1079 				version_res->me_max_version.minor_version);
1080 
1081 		if (version_res->host_version_supported) {
1082 			dev->version.major_version = HBM_MAJOR_VERSION;
1083 			dev->version.minor_version = HBM_MINOR_VERSION;
1084 		} else {
1085 			dev->version.major_version =
1086 				version_res->me_max_version.major_version;
1087 			dev->version.minor_version =
1088 				version_res->me_max_version.minor_version;
1089 		}
1090 
1091 		if (!mei_hbm_version_is_supported(dev)) {
1092 			dev_warn(dev->dev, "hbm: start: version mismatch - stopping the driver.\n");
1093 
1094 			dev->hbm_state = MEI_HBM_STOPPED;
1095 			if (mei_hbm_stop_req(dev)) {
1096 				dev_err(dev->dev, "hbm: start: failed to send stop request\n");
1097 				return -EIO;
1098 			}
1099 			break;
1100 		}
1101 
1102 		mei_hbm_config_features(dev);
1103 
1104 		if (dev->dev_state != MEI_DEV_INIT_CLIENTS ||
1105 		    dev->hbm_state != MEI_HBM_STARTING) {
1106 			dev_err(dev->dev, "hbm: start: state mismatch, [%d, %d]\n",
1107 				dev->dev_state, dev->hbm_state);
1108 			return -EPROTO;
1109 		}
1110 
1111 		if (mei_hbm_enum_clients_req(dev)) {
1112 			dev_err(dev->dev, "hbm: start: failed to send enumeration request\n");
1113 			return -EIO;
1114 		}
1115 
1116 		wake_up(&dev->wait_hbm_start);
1117 		break;
1118 
1119 	case CLIENT_CONNECT_RES_CMD:
1120 		dev_dbg(dev->dev, "hbm: client connect response: message received.\n");
1121 		mei_hbm_cl_res(dev, cl_cmd, MEI_FOP_CONNECT);
1122 		break;
1123 
1124 	case CLIENT_DISCONNECT_RES_CMD:
1125 		dev_dbg(dev->dev, "hbm: client disconnect response: message received.\n");
1126 		mei_hbm_cl_res(dev, cl_cmd, MEI_FOP_DISCONNECT);
1127 		break;
1128 
1129 	case MEI_FLOW_CONTROL_CMD:
1130 		dev_dbg(dev->dev, "hbm: client flow control response: message received.\n");
1131 
1132 		fctrl = (struct hbm_flow_control *)mei_msg;
1133 		mei_hbm_cl_tx_flow_ctrl_creds_res(dev, fctrl);
1134 		break;
1135 
1136 	case MEI_PG_ISOLATION_ENTRY_RES_CMD:
1137 		dev_dbg(dev->dev, "hbm: power gate isolation entry response received\n");
1138 		ret = mei_hbm_pg_enter_res(dev);
1139 		if (ret)
1140 			return ret;
1141 		break;
1142 
1143 	case MEI_PG_ISOLATION_EXIT_REQ_CMD:
1144 		dev_dbg(dev->dev, "hbm: power gate isolation exit request received\n");
1145 		ret = mei_hbm_pg_exit_res(dev);
1146 		if (ret)
1147 			return ret;
1148 		break;
1149 
1150 	case HOST_CLIENT_PROPERTIES_RES_CMD:
1151 		dev_dbg(dev->dev, "hbm: properties response: message received.\n");
1152 
1153 		dev->init_clients_timer = 0;
1154 
1155 		if (dev->dev_state != MEI_DEV_INIT_CLIENTS ||
1156 		    dev->hbm_state != MEI_HBM_CLIENT_PROPERTIES) {
1157 			dev_err(dev->dev, "hbm: properties response: state mismatch, [%d, %d]\n",
1158 				dev->dev_state, dev->hbm_state);
1159 			return -EPROTO;
1160 		}
1161 
1162 		props_res = (struct hbm_props_response *)mei_msg;
1163 
1164 		if (props_res->status) {
1165 			dev_err(dev->dev, "hbm: properties response: wrong status = %d %s\n",
1166 				props_res->status,
1167 				mei_hbm_status_str(props_res->status));
1168 			return -EPROTO;
1169 		}
1170 
1171 		mei_hbm_me_cl_add(dev, props_res);
1172 
1173 		/* request property for the next client */
1174 		if (mei_hbm_prop_req(dev, props_res->me_addr + 1))
1175 			return -EIO;
1176 
1177 		break;
1178 
1179 	case HOST_ENUM_RES_CMD:
1180 		dev_dbg(dev->dev, "hbm: enumeration response: message received\n");
1181 
1182 		dev->init_clients_timer = 0;
1183 
1184 		enum_res = (struct hbm_host_enum_response *) mei_msg;
1185 		BUILD_BUG_ON(sizeof(dev->me_clients_map)
1186 				< sizeof(enum_res->valid_addresses));
1187 		memcpy(dev->me_clients_map, enum_res->valid_addresses,
1188 				sizeof(enum_res->valid_addresses));
1189 
1190 		if (dev->dev_state != MEI_DEV_INIT_CLIENTS ||
1191 		    dev->hbm_state != MEI_HBM_ENUM_CLIENTS) {
1192 			dev_err(dev->dev, "hbm: enumeration response: state mismatch, [%d, %d]\n",
1193 				dev->dev_state, dev->hbm_state);
1194 			return -EPROTO;
1195 		}
1196 
1197 		dev->hbm_state = MEI_HBM_CLIENT_PROPERTIES;
1198 
1199 		/* first property request */
1200 		if (mei_hbm_prop_req(dev, 0))
1201 			return -EIO;
1202 
1203 		break;
1204 
1205 	case HOST_STOP_RES_CMD:
1206 		dev_dbg(dev->dev, "hbm: stop response: message received\n");
1207 
1208 		dev->init_clients_timer = 0;
1209 
1210 		if (dev->hbm_state != MEI_HBM_STOPPED) {
1211 			dev_err(dev->dev, "hbm: stop response: state mismatch, [%d, %d]\n",
1212 				dev->dev_state, dev->hbm_state);
1213 			return -EPROTO;
1214 		}
1215 
1216 		dev->dev_state = MEI_DEV_POWER_DOWN;
1217 		dev_info(dev->dev, "hbm: stop response: resetting.\n");
1218 		/* force the reset */
1219 		return -EPROTO;
1220 		break;
1221 
1222 	case CLIENT_DISCONNECT_REQ_CMD:
1223 		dev_dbg(dev->dev, "hbm: disconnect request: message received\n");
1224 
1225 		disconnect_req = (struct hbm_client_connect_request *)mei_msg;
1226 		mei_hbm_fw_disconnect_req(dev, disconnect_req);
1227 		break;
1228 
1229 	case ME_STOP_REQ_CMD:
1230 		dev_dbg(dev->dev, "hbm: stop request: message received\n");
1231 		dev->hbm_state = MEI_HBM_STOPPED;
1232 		if (mei_hbm_stop_req(dev)) {
1233 			dev_err(dev->dev, "hbm: stop request: failed to send stop request\n");
1234 			return -EIO;
1235 		}
1236 		break;
1237 
1238 	case MEI_HBM_ADD_CLIENT_REQ_CMD:
1239 		dev_dbg(dev->dev, "hbm: add client request received\n");
1240 		/*
1241 		 * after the host receives the enum_resp
1242 		 * message clients may be added or removed
1243 		 */
1244 		if (dev->hbm_state <= MEI_HBM_ENUM_CLIENTS ||
1245 		    dev->hbm_state >= MEI_HBM_STOPPED) {
1246 			dev_err(dev->dev, "hbm: add client: state mismatch, [%d, %d]\n",
1247 				dev->dev_state, dev->hbm_state);
1248 			return -EPROTO;
1249 		}
1250 		add_cl_req = (struct hbm_add_client_request *)mei_msg;
1251 		ret = mei_hbm_fw_add_cl_req(dev, add_cl_req);
1252 		if (ret) {
1253 			dev_err(dev->dev, "hbm: add client: failed to send response %d\n",
1254 				ret);
1255 			return -EIO;
1256 		}
1257 		dev_dbg(dev->dev, "hbm: add client request processed\n");
1258 		break;
1259 
1260 	case MEI_HBM_NOTIFY_RES_CMD:
1261 		dev_dbg(dev->dev, "hbm: notify response received\n");
1262 		mei_hbm_cl_res(dev, cl_cmd, notify_res_to_fop(cl_cmd));
1263 		break;
1264 
1265 	case MEI_HBM_NOTIFICATION_CMD:
1266 		dev_dbg(dev->dev, "hbm: notification\n");
1267 		mei_hbm_cl_notify(dev, cl_cmd);
1268 		break;
1269 
1270 	default:
1271 		BUG();
1272 		break;
1273 
1274 	}
1275 	return 0;
1276 }
1277 
1278