mei: fix NULL dereferencing during FW initiated disconnection
[muen/linux.git] / drivers / misc / mei / hbm.c
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