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1 | /* | |
2 | * IBM ASM Service Processor Device Driver | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License as published by | |
6 | * the Free Software Foundation; either version 2 of the License, or | |
7 | * (at your option) any later version. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, | |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | * GNU General Public License for more details. | |
13 | * | |
14 | * You should have received a copy of the GNU General Public License | |
15 | * along with this program; if not, write to the Free Software | |
16 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. | |
17 | * | |
18 | * Copyright (C) IBM Corporation, 2004 | |
19 | * | |
20 | * Author: Max Asböck <amax@us.ibm.com> | |
21 | * | |
22 | */ | |
23 | ||
24 | /* | |
25 | * Parts of this code are based on an article by Jonathan Corbet | |
26 | * that appeared in Linux Weekly News. | |
27 | */ | |
28 | ||
29 | ||
30 | /* | |
31 | * The IBMASM file virtual filesystem. It creates the following hierarchy | |
32 | * dynamically when mounted from user space: | |
33 | * | |
34 | * /ibmasm | |
35 | * |-- 0 | |
36 | * | |-- command | |
37 | * | |-- event | |
38 | * | |-- reverse_heartbeat | |
39 | * | `-- remote_video | |
40 | * | |-- depth | |
41 | * | |-- height | |
42 | * | `-- width | |
43 | * . | |
44 | * . | |
45 | * . | |
46 | * `-- n | |
47 | * |-- command | |
48 | * |-- event | |
49 | * |-- reverse_heartbeat | |
50 | * `-- remote_video | |
51 | * |-- depth | |
52 | * |-- height | |
53 | * `-- width | |
54 | * | |
55 | * For each service processor the following files are created: | |
56 | * | |
57 | * command: execute dot commands | |
58 | * write: execute a dot command on the service processor | |
59 | * read: return the result of a previously executed dot command | |
60 | * | |
61 | * events: listen for service processor events | |
62 | * read: sleep (interruptible) until an event occurs | |
63 | * write: wakeup sleeping event listener | |
64 | * | |
65 | * reverse_heartbeat: send a heartbeat to the service processor | |
66 | * read: sleep (interruptible) until the reverse heartbeat fails | |
67 | * write: wakeup sleeping heartbeat listener | |
68 | * | |
69 | * remote_video/width | |
70 | * remote_video/height | |
71 | * remote_video/width: control remote display settings | |
72 | * write: set value | |
73 | * read: read value | |
74 | */ | |
75 | ||
76 | #include <linux/fs.h> | |
77 | #include <linux/pagemap.h> | |
78 | #include <linux/slab.h> | |
79 | #include <asm/uaccess.h> | |
80 | #include <asm/io.h> | |
81 | #include "ibmasm.h" | |
82 | #include "remote.h" | |
83 | #include "dot_command.h" | |
84 | ||
85 | #define IBMASMFS_MAGIC 0x66726f67 | |
86 | ||
87 | static LIST_HEAD(service_processors); | |
88 | ||
89 | static struct inode *ibmasmfs_make_inode(struct super_block *sb, int mode); | |
90 | static void ibmasmfs_create_files (struct super_block *sb, struct dentry *root); | |
91 | static int ibmasmfs_fill_super (struct super_block *sb, void *data, int silent); | |
92 | ||
93 | ||
94 | static struct dentry *ibmasmfs_mount(struct file_system_type *fst, | |
95 | int flags, const char *name, void *data) | |
96 | { | |
97 | return mount_single(fst, flags, data, ibmasmfs_fill_super); | |
98 | } | |
99 | ||
100 | static const struct super_operations ibmasmfs_s_ops = { | |
101 | .statfs = simple_statfs, | |
102 | .drop_inode = generic_delete_inode, | |
103 | }; | |
104 | ||
105 | static const struct file_operations *ibmasmfs_dir_ops = &simple_dir_operations; | |
106 | ||
107 | static struct file_system_type ibmasmfs_type = { | |
108 | .owner = THIS_MODULE, | |
109 | .name = "ibmasmfs", | |
110 | .mount = ibmasmfs_mount, | |
111 | .kill_sb = kill_litter_super, | |
112 | }; | |
113 | ||
114 | static int ibmasmfs_fill_super (struct super_block *sb, void *data, int silent) | |
115 | { | |
116 | struct inode *root; | |
117 | struct dentry *root_dentry; | |
118 | ||
119 | sb->s_blocksize = PAGE_CACHE_SIZE; | |
120 | sb->s_blocksize_bits = PAGE_CACHE_SHIFT; | |
121 | sb->s_magic = IBMASMFS_MAGIC; | |
122 | sb->s_op = &ibmasmfs_s_ops; | |
123 | sb->s_time_gran = 1; | |
124 | ||
125 | root = ibmasmfs_make_inode (sb, S_IFDIR | 0500); | |
126 | if (!root) | |
127 | return -ENOMEM; | |
128 | ||
129 | root->i_op = &simple_dir_inode_operations; | |
130 | root->i_fop = ibmasmfs_dir_ops; | |
131 | ||
132 | root_dentry = d_make_root(root); | |
133 | if (!root_dentry) | |
134 | return -ENOMEM; | |
135 | sb->s_root = root_dentry; | |
136 | ||
137 | ibmasmfs_create_files(sb, root_dentry); | |
138 | return 0; | |
139 | } | |
140 | ||
141 | static struct inode *ibmasmfs_make_inode(struct super_block *sb, int mode) | |
142 | { | |
143 | struct inode *ret = new_inode(sb); | |
144 | ||
145 | if (ret) { | |
146 | ret->i_ino = get_next_ino(); | |
147 | ret->i_mode = mode; | |
148 | ret->i_atime = ret->i_mtime = ret->i_ctime = CURRENT_TIME; | |
149 | } | |
150 | return ret; | |
151 | } | |
152 | ||
153 | static struct dentry *ibmasmfs_create_file (struct super_block *sb, | |
154 | struct dentry *parent, | |
155 | const char *name, | |
156 | const struct file_operations *fops, | |
157 | void *data, | |
158 | int mode) | |
159 | { | |
160 | struct dentry *dentry; | |
161 | struct inode *inode; | |
162 | ||
163 | dentry = d_alloc_name(parent, name); | |
164 | if (!dentry) | |
165 | return NULL; | |
166 | ||
167 | inode = ibmasmfs_make_inode(sb, S_IFREG | mode); | |
168 | if (!inode) { | |
169 | dput(dentry); | |
170 | return NULL; | |
171 | } | |
172 | ||
173 | inode->i_fop = fops; | |
174 | inode->i_private = data; | |
175 | ||
176 | d_add(dentry, inode); | |
177 | return dentry; | |
178 | } | |
179 | ||
180 | static struct dentry *ibmasmfs_create_dir (struct super_block *sb, | |
181 | struct dentry *parent, | |
182 | const char *name) | |
183 | { | |
184 | struct dentry *dentry; | |
185 | struct inode *inode; | |
186 | ||
187 | dentry = d_alloc_name(parent, name); | |
188 | if (!dentry) | |
189 | return NULL; | |
190 | ||
191 | inode = ibmasmfs_make_inode(sb, S_IFDIR | 0500); | |
192 | if (!inode) { | |
193 | dput(dentry); | |
194 | return NULL; | |
195 | } | |
196 | ||
197 | inode->i_op = &simple_dir_inode_operations; | |
198 | inode->i_fop = ibmasmfs_dir_ops; | |
199 | ||
200 | d_add(dentry, inode); | |
201 | return dentry; | |
202 | } | |
203 | ||
204 | int ibmasmfs_register(void) | |
205 | { | |
206 | return register_filesystem(&ibmasmfs_type); | |
207 | } | |
208 | ||
209 | void ibmasmfs_unregister(void) | |
210 | { | |
211 | unregister_filesystem(&ibmasmfs_type); | |
212 | } | |
213 | ||
214 | void ibmasmfs_add_sp(struct service_processor *sp) | |
215 | { | |
216 | list_add(&sp->node, &service_processors); | |
217 | } | |
218 | ||
219 | /* struct to save state between command file operations */ | |
220 | struct ibmasmfs_command_data { | |
221 | struct service_processor *sp; | |
222 | struct command *command; | |
223 | }; | |
224 | ||
225 | /* struct to save state between event file operations */ | |
226 | struct ibmasmfs_event_data { | |
227 | struct service_processor *sp; | |
228 | struct event_reader reader; | |
229 | int active; | |
230 | }; | |
231 | ||
232 | /* struct to save state between reverse heartbeat file operations */ | |
233 | struct ibmasmfs_heartbeat_data { | |
234 | struct service_processor *sp; | |
235 | struct reverse_heartbeat heartbeat; | |
236 | int active; | |
237 | }; | |
238 | ||
239 | static int command_file_open(struct inode *inode, struct file *file) | |
240 | { | |
241 | struct ibmasmfs_command_data *command_data; | |
242 | ||
243 | if (!inode->i_private) | |
244 | return -ENODEV; | |
245 | ||
246 | command_data = kmalloc(sizeof(struct ibmasmfs_command_data), GFP_KERNEL); | |
247 | if (!command_data) | |
248 | return -ENOMEM; | |
249 | ||
250 | command_data->command = NULL; | |
251 | command_data->sp = inode->i_private; | |
252 | file->private_data = command_data; | |
253 | return 0; | |
254 | } | |
255 | ||
256 | static int command_file_close(struct inode *inode, struct file *file) | |
257 | { | |
258 | struct ibmasmfs_command_data *command_data = file->private_data; | |
259 | ||
260 | if (command_data->command) | |
261 | command_put(command_data->command); | |
262 | ||
263 | kfree(command_data); | |
264 | return 0; | |
265 | } | |
266 | ||
267 | static ssize_t command_file_read(struct file *file, char __user *buf, size_t count, loff_t *offset) | |
268 | { | |
269 | struct ibmasmfs_command_data *command_data = file->private_data; | |
270 | struct command *cmd; | |
271 | int len; | |
272 | unsigned long flags; | |
273 | ||
274 | if (*offset < 0) | |
275 | return -EINVAL; | |
276 | if (count == 0 || count > IBMASM_CMD_MAX_BUFFER_SIZE) | |
277 | return 0; | |
278 | if (*offset != 0) | |
279 | return 0; | |
280 | ||
281 | spin_lock_irqsave(&command_data->sp->lock, flags); | |
282 | cmd = command_data->command; | |
283 | if (cmd == NULL) { | |
284 | spin_unlock_irqrestore(&command_data->sp->lock, flags); | |
285 | return 0; | |
286 | } | |
287 | command_data->command = NULL; | |
288 | spin_unlock_irqrestore(&command_data->sp->lock, flags); | |
289 | ||
290 | if (cmd->status != IBMASM_CMD_COMPLETE) { | |
291 | command_put(cmd); | |
292 | return -EIO; | |
293 | } | |
294 | len = min(count, cmd->buffer_size); | |
295 | if (copy_to_user(buf, cmd->buffer, len)) { | |
296 | command_put(cmd); | |
297 | return -EFAULT; | |
298 | } | |
299 | command_put(cmd); | |
300 | ||
301 | return len; | |
302 | } | |
303 | ||
304 | static ssize_t command_file_write(struct file *file, const char __user *ubuff, size_t count, loff_t *offset) | |
305 | { | |
306 | struct ibmasmfs_command_data *command_data = file->private_data; | |
307 | struct command *cmd; | |
308 | unsigned long flags; | |
309 | ||
310 | if (*offset < 0) | |
311 | return -EINVAL; | |
312 | if (count == 0 || count > IBMASM_CMD_MAX_BUFFER_SIZE) | |
313 | return 0; | |
314 | if (*offset != 0) | |
315 | return 0; | |
316 | ||
317 | /* commands are executed sequentially, only one command at a time */ | |
318 | if (command_data->command) | |
319 | return -EAGAIN; | |
320 | ||
321 | cmd = ibmasm_new_command(command_data->sp, count); | |
322 | if (!cmd) | |
323 | return -ENOMEM; | |
324 | ||
325 | if (copy_from_user(cmd->buffer, ubuff, count)) { | |
326 | command_put(cmd); | |
327 | return -EFAULT; | |
328 | } | |
329 | ||
330 | spin_lock_irqsave(&command_data->sp->lock, flags); | |
331 | if (command_data->command) { | |
332 | spin_unlock_irqrestore(&command_data->sp->lock, flags); | |
333 | command_put(cmd); | |
334 | return -EAGAIN; | |
335 | } | |
336 | command_data->command = cmd; | |
337 | spin_unlock_irqrestore(&command_data->sp->lock, flags); | |
338 | ||
339 | ibmasm_exec_command(command_data->sp, cmd); | |
340 | ibmasm_wait_for_response(cmd, get_dot_command_timeout(cmd->buffer)); | |
341 | ||
342 | return count; | |
343 | } | |
344 | ||
345 | static int event_file_open(struct inode *inode, struct file *file) | |
346 | { | |
347 | struct ibmasmfs_event_data *event_data; | |
348 | struct service_processor *sp; | |
349 | ||
350 | if (!inode->i_private) | |
351 | return -ENODEV; | |
352 | ||
353 | sp = inode->i_private; | |
354 | ||
355 | event_data = kmalloc(sizeof(struct ibmasmfs_event_data), GFP_KERNEL); | |
356 | if (!event_data) | |
357 | return -ENOMEM; | |
358 | ||
359 | ibmasm_event_reader_register(sp, &event_data->reader); | |
360 | ||
361 | event_data->sp = sp; | |
362 | event_data->active = 0; | |
363 | file->private_data = event_data; | |
364 | return 0; | |
365 | } | |
366 | ||
367 | static int event_file_close(struct inode *inode, struct file *file) | |
368 | { | |
369 | struct ibmasmfs_event_data *event_data = file->private_data; | |
370 | ||
371 | ibmasm_event_reader_unregister(event_data->sp, &event_data->reader); | |
372 | kfree(event_data); | |
373 | return 0; | |
374 | } | |
375 | ||
376 | static ssize_t event_file_read(struct file *file, char __user *buf, size_t count, loff_t *offset) | |
377 | { | |
378 | struct ibmasmfs_event_data *event_data = file->private_data; | |
379 | struct event_reader *reader = &event_data->reader; | |
380 | struct service_processor *sp = event_data->sp; | |
381 | int ret; | |
382 | unsigned long flags; | |
383 | ||
384 | if (*offset < 0) | |
385 | return -EINVAL; | |
386 | if (count == 0 || count > IBMASM_EVENT_MAX_SIZE) | |
387 | return 0; | |
388 | if (*offset != 0) | |
389 | return 0; | |
390 | ||
391 | spin_lock_irqsave(&sp->lock, flags); | |
392 | if (event_data->active) { | |
393 | spin_unlock_irqrestore(&sp->lock, flags); | |
394 | return -EBUSY; | |
395 | } | |
396 | event_data->active = 1; | |
397 | spin_unlock_irqrestore(&sp->lock, flags); | |
398 | ||
399 | ret = ibmasm_get_next_event(sp, reader); | |
400 | if (ret <= 0) | |
401 | goto out; | |
402 | ||
403 | if (count < reader->data_size) { | |
404 | ret = -EINVAL; | |
405 | goto out; | |
406 | } | |
407 | ||
408 | if (copy_to_user(buf, reader->data, reader->data_size)) { | |
409 | ret = -EFAULT; | |
410 | goto out; | |
411 | } | |
412 | ret = reader->data_size; | |
413 | ||
414 | out: | |
415 | event_data->active = 0; | |
416 | return ret; | |
417 | } | |
418 | ||
419 | static ssize_t event_file_write(struct file *file, const char __user *buf, size_t count, loff_t *offset) | |
420 | { | |
421 | struct ibmasmfs_event_data *event_data = file->private_data; | |
422 | ||
423 | if (*offset < 0) | |
424 | return -EINVAL; | |
425 | if (count != 1) | |
426 | return 0; | |
427 | if (*offset != 0) | |
428 | return 0; | |
429 | ||
430 | ibmasm_cancel_next_event(&event_data->reader); | |
431 | return 0; | |
432 | } | |
433 | ||
434 | static int r_heartbeat_file_open(struct inode *inode, struct file *file) | |
435 | { | |
436 | struct ibmasmfs_heartbeat_data *rhbeat; | |
437 | ||
438 | if (!inode->i_private) | |
439 | return -ENODEV; | |
440 | ||
441 | rhbeat = kmalloc(sizeof(struct ibmasmfs_heartbeat_data), GFP_KERNEL); | |
442 | if (!rhbeat) | |
443 | return -ENOMEM; | |
444 | ||
445 | rhbeat->sp = inode->i_private; | |
446 | rhbeat->active = 0; | |
447 | ibmasm_init_reverse_heartbeat(rhbeat->sp, &rhbeat->heartbeat); | |
448 | file->private_data = rhbeat; | |
449 | return 0; | |
450 | } | |
451 | ||
452 | static int r_heartbeat_file_close(struct inode *inode, struct file *file) | |
453 | { | |
454 | struct ibmasmfs_heartbeat_data *rhbeat = file->private_data; | |
455 | ||
456 | kfree(rhbeat); | |
457 | return 0; | |
458 | } | |
459 | ||
460 | static ssize_t r_heartbeat_file_read(struct file *file, char __user *buf, size_t count, loff_t *offset) | |
461 | { | |
462 | struct ibmasmfs_heartbeat_data *rhbeat = file->private_data; | |
463 | unsigned long flags; | |
464 | int result; | |
465 | ||
466 | if (*offset < 0) | |
467 | return -EINVAL; | |
468 | if (count == 0 || count > 1024) | |
469 | return 0; | |
470 | if (*offset != 0) | |
471 | return 0; | |
472 | ||
473 | /* allow only one reverse heartbeat per process */ | |
474 | spin_lock_irqsave(&rhbeat->sp->lock, flags); | |
475 | if (rhbeat->active) { | |
476 | spin_unlock_irqrestore(&rhbeat->sp->lock, flags); | |
477 | return -EBUSY; | |
478 | } | |
479 | rhbeat->active = 1; | |
480 | spin_unlock_irqrestore(&rhbeat->sp->lock, flags); | |
481 | ||
482 | result = ibmasm_start_reverse_heartbeat(rhbeat->sp, &rhbeat->heartbeat); | |
483 | rhbeat->active = 0; | |
484 | ||
485 | return result; | |
486 | } | |
487 | ||
488 | static ssize_t r_heartbeat_file_write(struct file *file, const char __user *buf, size_t count, loff_t *offset) | |
489 | { | |
490 | struct ibmasmfs_heartbeat_data *rhbeat = file->private_data; | |
491 | ||
492 | if (*offset < 0) | |
493 | return -EINVAL; | |
494 | if (count != 1) | |
495 | return 0; | |
496 | if (*offset != 0) | |
497 | return 0; | |
498 | ||
499 | if (rhbeat->active) | |
500 | ibmasm_stop_reverse_heartbeat(&rhbeat->heartbeat); | |
501 | ||
502 | return 1; | |
503 | } | |
504 | ||
505 | static int remote_settings_file_open(struct inode *inode, struct file *file) | |
506 | { | |
507 | file->private_data = inode->i_private; | |
508 | return 0; | |
509 | } | |
510 | ||
511 | static int remote_settings_file_close(struct inode *inode, struct file *file) | |
512 | { | |
513 | return 0; | |
514 | } | |
515 | ||
516 | static ssize_t remote_settings_file_read(struct file *file, char __user *buf, size_t count, loff_t *offset) | |
517 | { | |
518 | void __iomem *address = (void __iomem *)file->private_data; | |
519 | unsigned char *page; | |
520 | int retval; | |
521 | int len = 0; | |
522 | unsigned int value; | |
523 | ||
524 | if (*offset < 0) | |
525 | return -EINVAL; | |
526 | if (count == 0 || count > 1024) | |
527 | return 0; | |
528 | if (*offset != 0) | |
529 | return 0; | |
530 | ||
531 | page = (unsigned char *)__get_free_page(GFP_KERNEL); | |
532 | if (!page) | |
533 | return -ENOMEM; | |
534 | ||
535 | value = readl(address); | |
536 | len = sprintf(page, "%d\n", value); | |
537 | ||
538 | if (copy_to_user(buf, page, len)) { | |
539 | retval = -EFAULT; | |
540 | goto exit; | |
541 | } | |
542 | *offset += len; | |
543 | retval = len; | |
544 | ||
545 | exit: | |
546 | free_page((unsigned long)page); | |
547 | return retval; | |
548 | } | |
549 | ||
550 | static ssize_t remote_settings_file_write(struct file *file, const char __user *ubuff, size_t count, loff_t *offset) | |
551 | { | |
552 | void __iomem *address = (void __iomem *)file->private_data; | |
553 | char *buff; | |
554 | unsigned int value; | |
555 | ||
556 | if (*offset < 0) | |
557 | return -EINVAL; | |
558 | if (count == 0 || count > 1024) | |
559 | return 0; | |
560 | if (*offset != 0) | |
561 | return 0; | |
562 | ||
563 | buff = kzalloc (count + 1, GFP_KERNEL); | |
564 | if (!buff) | |
565 | return -ENOMEM; | |
566 | ||
567 | ||
568 | if (copy_from_user(buff, ubuff, count)) { | |
569 | kfree(buff); | |
570 | return -EFAULT; | |
571 | } | |
572 | ||
573 | value = simple_strtoul(buff, NULL, 10); | |
574 | writel(value, address); | |
575 | kfree(buff); | |
576 | ||
577 | return count; | |
578 | } | |
579 | ||
580 | static const struct file_operations command_fops = { | |
581 | .open = command_file_open, | |
582 | .release = command_file_close, | |
583 | .read = command_file_read, | |
584 | .write = command_file_write, | |
585 | .llseek = generic_file_llseek, | |
586 | }; | |
587 | ||
588 | static const struct file_operations event_fops = { | |
589 | .open = event_file_open, | |
590 | .release = event_file_close, | |
591 | .read = event_file_read, | |
592 | .write = event_file_write, | |
593 | .llseek = generic_file_llseek, | |
594 | }; | |
595 | ||
596 | static const struct file_operations r_heartbeat_fops = { | |
597 | .open = r_heartbeat_file_open, | |
598 | .release = r_heartbeat_file_close, | |
599 | .read = r_heartbeat_file_read, | |
600 | .write = r_heartbeat_file_write, | |
601 | .llseek = generic_file_llseek, | |
602 | }; | |
603 | ||
604 | static const struct file_operations remote_settings_fops = { | |
605 | .open = remote_settings_file_open, | |
606 | .release = remote_settings_file_close, | |
607 | .read = remote_settings_file_read, | |
608 | .write = remote_settings_file_write, | |
609 | .llseek = generic_file_llseek, | |
610 | }; | |
611 | ||
612 | ||
613 | static void ibmasmfs_create_files (struct super_block *sb, struct dentry *root) | |
614 | { | |
615 | struct list_head *entry; | |
616 | struct service_processor *sp; | |
617 | ||
618 | list_for_each(entry, &service_processors) { | |
619 | struct dentry *dir; | |
620 | struct dentry *remote_dir; | |
621 | sp = list_entry(entry, struct service_processor, node); | |
622 | dir = ibmasmfs_create_dir(sb, root, sp->dirname); | |
623 | if (!dir) | |
624 | continue; | |
625 | ||
626 | ibmasmfs_create_file(sb, dir, "command", &command_fops, sp, S_IRUSR|S_IWUSR); | |
627 | ibmasmfs_create_file(sb, dir, "event", &event_fops, sp, S_IRUSR|S_IWUSR); | |
628 | ibmasmfs_create_file(sb, dir, "reverse_heartbeat", &r_heartbeat_fops, sp, S_IRUSR|S_IWUSR); | |
629 | ||
630 | remote_dir = ibmasmfs_create_dir(sb, dir, "remote_video"); | |
631 | if (!remote_dir) | |
632 | continue; | |
633 | ||
634 | ibmasmfs_create_file(sb, remote_dir, "width", &remote_settings_fops, (void *)display_width(sp), S_IRUSR|S_IWUSR); | |
635 | ibmasmfs_create_file(sb, remote_dir, "height", &remote_settings_fops, (void *)display_height(sp), S_IRUSR|S_IWUSR); | |
636 | ibmasmfs_create_file(sb, remote_dir, "depth", &remote_settings_fops, (void *)display_depth(sp), S_IRUSR|S_IWUSR); | |
637 | } | |
638 | } |