1e5cb1f704f809d56c350969953567e091203227
[muen/linux.git] / drivers / misc / mei / interrupt.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
18 #include <linux/export.h>
19 #include <linux/kthread.h>
20 #include <linux/interrupt.h>
21 #include <linux/fs.h>
22 #include <linux/jiffies.h>
23 #include <linux/slab.h>
24 #include <linux/pm_runtime.h>
25
26 #include <linux/mei.h>
27
28 #include "mei_dev.h"
29 #include "hbm.h"
30 #include "client.h"
31
32
33 /**
34  * mei_irq_compl_handler - dispatch complete handlers
35  *      for the completed callbacks
36  *
37  * @dev: mei device
38  * @compl_list: list of completed cbs
39  */
40 void mei_irq_compl_handler(struct mei_device *dev, struct mei_cl_cb *compl_list)
41 {
42         struct mei_cl_cb *cb, *next;
43         struct mei_cl *cl;
44
45         list_for_each_entry_safe(cb, next, &compl_list->list, list) {
46                 cl = cb->cl;
47                 list_del_init(&cb->list);
48
49                 dev_dbg(dev->dev, "completing call back.\n");
50                 if (cl == &dev->iamthif_cl)
51                         mei_amthif_complete(cl, cb);
52                 else
53                         mei_cl_complete(cl, cb);
54         }
55 }
56 EXPORT_SYMBOL_GPL(mei_irq_compl_handler);
57
58 /**
59  * mei_cl_hbm_equal - check if hbm is addressed to the client
60  *
61  * @cl: host client
62  * @mei_hdr: header of mei client message
63  *
64  * Return: true if matches, false otherwise
65  */
66 static inline int mei_cl_hbm_equal(struct mei_cl *cl,
67                         struct mei_msg_hdr *mei_hdr)
68 {
69         return  mei_cl_host_addr(cl) == mei_hdr->host_addr &&
70                 mei_cl_me_id(cl) == mei_hdr->me_addr;
71 }
72
73 /**
74  * mei_irq_discard_msg  - discard received message
75  *
76  * @dev: mei device
77  * @hdr: message header
78  */
79 static inline
80 void mei_irq_discard_msg(struct mei_device *dev, struct mei_msg_hdr *hdr)
81 {
82         /*
83          * no need to check for size as it is guarantied
84          * that length fits into rd_msg_buf
85          */
86         mei_read_slots(dev, dev->rd_msg_buf, hdr->length);
87         dev_dbg(dev->dev, "discarding message " MEI_HDR_FMT "\n",
88                 MEI_HDR_PRM(hdr));
89 }
90
91 /**
92  * mei_cl_irq_read_msg - process client message
93  *
94  * @cl: reading client
95  * @mei_hdr: header of mei client message
96  * @complete_list: completion list
97  *
98  * Return: always 0
99  */
100 int mei_cl_irq_read_msg(struct mei_cl *cl,
101                        struct mei_msg_hdr *mei_hdr,
102                        struct mei_cl_cb *complete_list)
103 {
104         struct mei_device *dev = cl->dev;
105         struct mei_cl_cb *cb;
106         unsigned char *buffer = NULL;
107         size_t buf_sz;
108
109         cb = list_first_entry_or_null(&cl->rd_pending, struct mei_cl_cb, list);
110         if (!cb) {
111                 cl_err(dev, cl, "pending read cb not found\n");
112                 goto out;
113         }
114
115         if (!mei_cl_is_connected(cl)) {
116                 cl_dbg(dev, cl, "not connected\n");
117                 cb->status = -ENODEV;
118                 goto out;
119         }
120
121         if (cb->buf.size == 0 || cb->buf.data == NULL) {
122                 cl_err(dev, cl, "response buffer is not allocated.\n");
123                 list_move_tail(&cb->list, &complete_list->list);
124                 cb->status = -ENOMEM;
125                 goto out;
126         }
127
128         buf_sz = mei_hdr->length + cb->buf_idx;
129         /* catch for integer overflow */
130         if (buf_sz < cb->buf_idx) {
131                 cl_err(dev, cl, "message is too big len %d idx %zu\n",
132                        mei_hdr->length, cb->buf_idx);
133
134                 list_move_tail(&cb->list, &complete_list->list);
135                 cb->status = -EMSGSIZE;
136                 goto out;
137         }
138
139         if (cb->buf.size < buf_sz) {
140                 cl_dbg(dev, cl, "message overflow. size %zu len %d idx %zu\n",
141                         cb->buf.size, mei_hdr->length, cb->buf_idx);
142                 buffer = krealloc(cb->buf.data, buf_sz, GFP_KERNEL);
143
144                 if (!buffer) {
145                         cb->status = -ENOMEM;
146                         list_move_tail(&cb->list, &complete_list->list);
147                         goto out;
148                 }
149                 cb->buf.data = buffer;
150                 cb->buf.size = buf_sz;
151         }
152
153         buffer = cb->buf.data + cb->buf_idx;
154         mei_read_slots(dev, buffer, mei_hdr->length);
155
156         cb->buf_idx += mei_hdr->length;
157
158         if (mei_hdr->msg_complete) {
159                 cl_dbg(dev, cl, "completed read length = %zu\n", cb->buf_idx);
160                 list_move_tail(&cb->list, &complete_list->list);
161         } else {
162                 pm_runtime_mark_last_busy(dev->dev);
163                 pm_request_autosuspend(dev->dev);
164         }
165
166 out:
167         if (!buffer)
168                 mei_irq_discard_msg(dev, mei_hdr);
169
170         return 0;
171 }
172
173 /**
174  * mei_cl_irq_disconnect_rsp - send disconnection response message
175  *
176  * @cl: client
177  * @cb: callback block.
178  * @cmpl_list: complete list.
179  *
180  * Return: 0, OK; otherwise, error.
181  */
182 static int mei_cl_irq_disconnect_rsp(struct mei_cl *cl, struct mei_cl_cb *cb,
183                                      struct mei_cl_cb *cmpl_list)
184 {
185         struct mei_device *dev = cl->dev;
186         u32 msg_slots;
187         int slots;
188         int ret;
189
190         slots = mei_hbuf_empty_slots(dev);
191         msg_slots = mei_data2slots(sizeof(struct hbm_client_connect_response));
192
193         if (slots < msg_slots)
194                 return -EMSGSIZE;
195
196         ret = mei_hbm_cl_disconnect_rsp(dev, cl);
197         mei_cl_set_disconnected(cl);
198         mei_io_cb_free(cb);
199         mei_me_cl_put(cl->me_cl);
200         cl->me_cl = NULL;
201
202         return ret;
203 }
204
205 /**
206  * mei_cl_irq_read - processes client read related operation from the
207  *      interrupt thread context - request for flow control credits
208  *
209  * @cl: client
210  * @cb: callback block.
211  * @cmpl_list: complete list.
212  *
213  * Return: 0, OK; otherwise, error.
214  */
215 static int mei_cl_irq_read(struct mei_cl *cl, struct mei_cl_cb *cb,
216                            struct mei_cl_cb *cmpl_list)
217 {
218         struct mei_device *dev = cl->dev;
219         u32 msg_slots;
220         int slots;
221         int ret;
222
223         msg_slots = mei_data2slots(sizeof(struct hbm_flow_control));
224         slots = mei_hbuf_empty_slots(dev);
225
226         if (slots < msg_slots)
227                 return -EMSGSIZE;
228
229         ret = mei_hbm_cl_flow_control_req(dev, cl);
230         if (ret) {
231                 cl->status = ret;
232                 cb->buf_idx = 0;
233                 list_move_tail(&cb->list, &cmpl_list->list);
234                 return ret;
235         }
236
237         list_move_tail(&cb->list, &cl->rd_pending);
238
239         return 0;
240 }
241
242 static inline bool hdr_is_hbm(struct mei_msg_hdr *mei_hdr)
243 {
244         return mei_hdr->host_addr == 0 && mei_hdr->me_addr == 0;
245 }
246
247 static inline bool hdr_is_fixed(struct mei_msg_hdr *mei_hdr)
248 {
249         return mei_hdr->host_addr == 0 && mei_hdr->me_addr != 0;
250 }
251
252 /**
253  * mei_irq_read_handler - bottom half read routine after ISR to
254  * handle the read processing.
255  *
256  * @dev: the device structure
257  * @cmpl_list: An instance of our list structure
258  * @slots: slots to read.
259  *
260  * Return: 0 on success, <0 on failure.
261  */
262 int mei_irq_read_handler(struct mei_device *dev,
263                 struct mei_cl_cb *cmpl_list, s32 *slots)
264 {
265         struct mei_msg_hdr *mei_hdr;
266         struct mei_cl *cl;
267         int ret;
268
269         if (!dev->rd_msg_hdr) {
270                 dev->rd_msg_hdr = mei_read_hdr(dev);
271                 (*slots)--;
272                 dev_dbg(dev->dev, "slots =%08x.\n", *slots);
273         }
274         mei_hdr = (struct mei_msg_hdr *) &dev->rd_msg_hdr;
275         dev_dbg(dev->dev, MEI_HDR_FMT, MEI_HDR_PRM(mei_hdr));
276
277         if (mei_hdr->reserved || !dev->rd_msg_hdr) {
278                 dev_err(dev->dev, "corrupted message header 0x%08X\n",
279                                 dev->rd_msg_hdr);
280                 ret = -EBADMSG;
281                 goto end;
282         }
283
284         if (mei_slots2data(*slots) < mei_hdr->length) {
285                 dev_err(dev->dev, "less data available than length=%08x.\n",
286                                 *slots);
287                 /* we can't read the message */
288                 ret = -ENODATA;
289                 goto end;
290         }
291
292         /*  HBM message */
293         if (hdr_is_hbm(mei_hdr)) {
294                 ret = mei_hbm_dispatch(dev, mei_hdr);
295                 if (ret) {
296                         dev_dbg(dev->dev, "mei_hbm_dispatch failed ret = %d\n",
297                                         ret);
298                         goto end;
299                 }
300                 goto reset_slots;
301         }
302
303         /* find recipient cl */
304         list_for_each_entry(cl, &dev->file_list, link) {
305                 if (mei_cl_hbm_equal(cl, mei_hdr)) {
306                         cl_dbg(dev, cl, "got a message\n");
307                         break;
308                 }
309         }
310
311         /* if no recipient cl was found we assume corrupted header */
312         if (&cl->link == &dev->file_list) {
313                 /* A message for not connected fixed address clients
314                  * should be silently discarded
315                  */
316                 if (hdr_is_fixed(mei_hdr)) {
317                         mei_irq_discard_msg(dev, mei_hdr);
318                         ret = 0;
319                         goto reset_slots;
320                 }
321                 dev_err(dev->dev, "no destination client found 0x%08X\n",
322                                 dev->rd_msg_hdr);
323                 ret = -EBADMSG;
324                 goto end;
325         }
326
327         if (cl == &dev->iamthif_cl) {
328                 ret = mei_amthif_irq_read_msg(cl, mei_hdr, cmpl_list);
329         } else {
330                 ret = mei_cl_irq_read_msg(cl, mei_hdr, cmpl_list);
331         }
332
333
334 reset_slots:
335         /* reset the number of slots and header */
336         *slots = mei_count_full_read_slots(dev);
337         dev->rd_msg_hdr = 0;
338
339         if (*slots == -EOVERFLOW) {
340                 /* overflow - reset */
341                 dev_err(dev->dev, "resetting due to slots overflow.\n");
342                 /* set the event since message has been read */
343                 ret = -ERANGE;
344                 goto end;
345         }
346 end:
347         return ret;
348 }
349 EXPORT_SYMBOL_GPL(mei_irq_read_handler);
350
351
352 /**
353  * mei_irq_write_handler -  dispatch write requests
354  *  after irq received
355  *
356  * @dev: the device structure
357  * @cmpl_list: An instance of our list structure
358  *
359  * Return: 0 on success, <0 on failure.
360  */
361 int mei_irq_write_handler(struct mei_device *dev, struct mei_cl_cb *cmpl_list)
362 {
363
364         struct mei_cl *cl;
365         struct mei_cl_cb *cb, *next;
366         struct mei_cl_cb *list;
367         s32 slots;
368         int ret;
369
370
371         if (!mei_hbuf_acquire(dev))
372                 return 0;
373
374         slots = mei_hbuf_empty_slots(dev);
375         if (slots <= 0)
376                 return -EMSGSIZE;
377
378         /* complete all waiting for write CB */
379         dev_dbg(dev->dev, "complete all waiting for write cb.\n");
380
381         list = &dev->write_waiting_list;
382         list_for_each_entry_safe(cb, next, &list->list, list) {
383                 cl = cb->cl;
384
385                 cl->status = 0;
386                 cl_dbg(dev, cl, "MEI WRITE COMPLETE\n");
387                 cl->writing_state = MEI_WRITE_COMPLETE;
388                 list_move_tail(&cb->list, &cmpl_list->list);
389         }
390
391         /* complete control write list CB */
392         dev_dbg(dev->dev, "complete control write list cb.\n");
393         list_for_each_entry_safe(cb, next, &dev->ctrl_wr_list.list, list) {
394                 cl = cb->cl;
395                 switch (cb->fop_type) {
396                 case MEI_FOP_DISCONNECT:
397                         /* send disconnect message */
398                         ret = mei_cl_irq_disconnect(cl, cb, cmpl_list);
399                         if (ret)
400                                 return ret;
401
402                         break;
403                 case MEI_FOP_READ:
404                         /* send flow control message */
405                         ret = mei_cl_irq_read(cl, cb, cmpl_list);
406                         if (ret)
407                                 return ret;
408
409                         break;
410                 case MEI_FOP_CONNECT:
411                         /* connect message */
412                         ret = mei_cl_irq_connect(cl, cb, cmpl_list);
413                         if (ret)
414                                 return ret;
415
416                         break;
417                 case MEI_FOP_DISCONNECT_RSP:
418                         /* send disconnect resp */
419                         ret = mei_cl_irq_disconnect_rsp(cl, cb, cmpl_list);
420                         if (ret)
421                                 return ret;
422                         break;
423
424                 case MEI_FOP_NOTIFY_START:
425                 case MEI_FOP_NOTIFY_STOP:
426                         ret = mei_cl_irq_notify(cl, cb, cmpl_list);
427                         if (ret)
428                                 return ret;
429                         break;
430                 default:
431                         BUG();
432                 }
433
434         }
435         /* complete  write list CB */
436         dev_dbg(dev->dev, "complete write list cb.\n");
437         list_for_each_entry_safe(cb, next, &dev->write_list.list, list) {
438                 cl = cb->cl;
439                 if (cl == &dev->iamthif_cl)
440                         ret = mei_amthif_irq_write(cl, cb, cmpl_list);
441                 else
442                         ret = mei_cl_irq_write(cl, cb, cmpl_list);
443                 if (ret)
444                         return ret;
445         }
446         return 0;
447 }
448 EXPORT_SYMBOL_GPL(mei_irq_write_handler);
449
450
451 /**
452  * mei_connect_timeout  - connect/disconnect timeouts
453  *
454  * @cl: host client
455  */
456 static void mei_connect_timeout(struct mei_cl *cl)
457 {
458         struct mei_device *dev = cl->dev;
459
460         if (cl->state == MEI_FILE_CONNECTING) {
461                 if (dev->hbm_f_dot_supported) {
462                         cl->state = MEI_FILE_DISCONNECT_REQUIRED;
463                         wake_up(&cl->wait);
464                         return;
465                 }
466         }
467         mei_reset(dev);
468 }
469
470 /**
471  * mei_timer - timer function.
472  *
473  * @work: pointer to the work_struct structure
474  *
475  */
476 void mei_timer(struct work_struct *work)
477 {
478         struct mei_cl *cl;
479
480         struct mei_device *dev = container_of(work,
481                                         struct mei_device, timer_work.work);
482
483
484         mutex_lock(&dev->device_lock);
485
486         /* Catch interrupt stalls during HBM init handshake */
487         if (dev->dev_state == MEI_DEV_INIT_CLIENTS &&
488             dev->hbm_state != MEI_HBM_IDLE) {
489
490                 if (dev->init_clients_timer) {
491                         if (--dev->init_clients_timer == 0) {
492                                 dev_err(dev->dev, "timer: init clients timeout hbm_state = %d.\n",
493                                         dev->hbm_state);
494                                 mei_reset(dev);
495                                 goto out;
496                         }
497                 }
498         }
499
500         if (dev->dev_state != MEI_DEV_ENABLED)
501                 goto out;
502
503         /*** connect/disconnect timeouts ***/
504         list_for_each_entry(cl, &dev->file_list, link) {
505                 if (cl->timer_count) {
506                         if (--cl->timer_count == 0) {
507                                 dev_err(dev->dev, "timer: connect/disconnect timeout.\n");
508                                 mei_connect_timeout(cl);
509                                 goto out;
510                         }
511                 }
512         }
513
514         if (!mei_cl_is_connected(&dev->iamthif_cl))
515                 goto out;
516
517         if (dev->iamthif_stall_timer) {
518                 if (--dev->iamthif_stall_timer == 0) {
519                         dev_err(dev->dev, "timer: amthif  hanged.\n");
520                         mei_reset(dev);
521                         dev->iamthif_canceled = false;
522                         dev->iamthif_state = MEI_IAMTHIF_IDLE;
523
524                         mei_io_cb_free(dev->iamthif_current_cb);
525                         dev->iamthif_current_cb = NULL;
526
527                         dev->iamthif_fp = NULL;
528                         mei_amthif_run_next_cmd(dev);
529                 }
530         }
531
532 out:
533         if (dev->dev_state != MEI_DEV_DISABLED)
534                 schedule_delayed_work(&dev->timer_work, 2 * HZ);
535         mutex_unlock(&dev->device_lock);
536 }