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 * dymamically 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 <asm/uaccess.h>
79 #include <asm/io.h>
80 #include "ibmasm.h"
81 #include "remote.h"
82 #include "dot_command.h"
83
84 #define IBMASMFS_MAGIC 0x66726f67
85
86 static LIST_HEAD(service_processors);
87
88 static struct inode *ibmasmfs_make_inode(struct super_block *sb, int mode);
89 static void ibmasmfs_create_files (struct super_block *sb, struct dentry *root);
90 static int ibmasmfs_fill_super (struct super_block *sb, void *data, int silent);
91
92
93 static int ibmasmfs_get_super(struct file_system_type *fst,
94 int flags, const char *name, void *data,
95 struct vfsmount *mnt)
96 {
97 return get_sb_single(fst, flags, data, ibmasmfs_fill_super, mnt);
98 }
99
100 static 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 .get_sb = ibmasmfs_get_super,
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_alloc_root(root);
133 if (!root_dentry) {
134 iput(root);
135 return -ENOMEM;
136 }
137 sb->s_root = root_dentry;
138
139 ibmasmfs_create_files(sb, root_dentry);
140 return 0;
141 }
142
143 static struct inode *ibmasmfs_make_inode(struct super_block *sb, int mode)
144 {
145 struct inode *ret = new_inode(sb);
146
147 if (ret) {
148 ret->i_mode = mode;
149 ret->i_atime = ret->i_mtime = ret->i_ctime = CURRENT_TIME;
150 }
151 return ret;
152 }
153
154 static struct dentry *ibmasmfs_create_file (struct super_block *sb,
155 struct dentry *parent,
156 const char *name,
157 const struct file_operations *fops,
158 void *data,
159 int mode)
160 {
161 struct dentry *dentry;
162 struct inode *inode;
163
164 dentry = d_alloc_name(parent, name);
165 if (!dentry)
166 return NULL;
167
168 inode = ibmasmfs_make_inode(sb, S_IFREG | mode);
169 if (!inode) {
170 dput(dentry);
171 return NULL;
172 }
173
174 inode->i_fop = fops;
175 inode->i_private = data;
176
177 d_add(dentry, inode);
178 return dentry;
179 }
180
181 static struct dentry *ibmasmfs_create_dir (struct super_block *sb,
182 struct dentry *parent,
183 const char *name)
184 {
185 struct dentry *dentry;
186 struct inode *inode;
187
188 dentry = d_alloc_name(parent, name);
189 if (!dentry)
190 return NULL;
191
192 inode = ibmasmfs_make_inode(sb, S_IFDIR | 0500);
193 if (!inode) {
194 dput(dentry);
195 return NULL;
196 }
197
198 inode->i_op = &simple_dir_inode_operations;
199 inode->i_fop = ibmasmfs_dir_ops;
200
201 d_add(dentry, inode);
202 return dentry;
203 }
204
205 int ibmasmfs_register(void)
206 {
207 return register_filesystem(&ibmasmfs_type);
208 }
209
210 void ibmasmfs_unregister(void)
211 {
212 unregister_filesystem(&ibmasmfs_type);
213 }
214
215 void ibmasmfs_add_sp(struct service_processor *sp)
216 {
217 list_add(&sp->node, &service_processors);
218 }
219
220 /* struct to save state between command file operations */
221 struct ibmasmfs_command_data {
222 struct service_processor *sp;
223 struct command *command;
224 };
225
226 /* struct to save state between event file operations */
227 struct ibmasmfs_event_data {
228 struct service_processor *sp;
229 struct event_reader reader;
230 int active;
231 };
232
233 /* struct to save state between reverse heartbeat file operations */
234 struct ibmasmfs_heartbeat_data {
235 struct service_processor *sp;
236 struct reverse_heartbeat heartbeat;
237 int active;
238 };
239
240 static int command_file_open(struct inode *inode, struct file *file)
241 {
242 struct ibmasmfs_command_data *command_data;
243
244 if (!inode->i_private)
245 return -ENODEV;
246
247 command_data = kmalloc(sizeof(struct ibmasmfs_command_data), GFP_KERNEL);
248 if (!command_data)
249 return -ENOMEM;
250
251 command_data->command = NULL;
252 command_data->sp = inode->i_private;
253 file->private_data = command_data;
254 return 0;
255 }
256
257 static int command_file_close(struct inode *inode, struct file *file)
258 {
259 struct ibmasmfs_command_data *command_data = file->private_data;
260
261 if (command_data->command)
262 command_put(command_data->command);
263
264 kfree(command_data);
265 return 0;
266 }
267
268 static ssize_t command_file_read(struct file *file, char __user *buf, size_t count, loff_t *offset)
269 {
270 struct ibmasmfs_command_data *command_data = file->private_data;
271 struct command *cmd;
272 int len;
273 unsigned long flags;
274
275 if (*offset < 0)
276 return -EINVAL;
277 if (count == 0 || count > IBMASM_CMD_MAX_BUFFER_SIZE)
278 return 0;
279 if (*offset != 0)
280 return 0;
281
282 spin_lock_irqsave(&command_data->sp->lock, flags);
283 cmd = command_data->command;
284 if (cmd == NULL) {
285 spin_unlock_irqrestore(&command_data->sp->lock, flags);
286 return 0;
287 }
288 command_data->command = NULL;
289 spin_unlock_irqrestore(&command_data->sp->lock, flags);
290
291 if (cmd->status != IBMASM_CMD_COMPLETE) {
292 command_put(cmd);
293 return -EIO;
294 }
295 len = min(count, cmd->buffer_size);
296 if (copy_to_user(buf, cmd->buffer, len)) {
297 command_put(cmd);
298 return -EFAULT;
299 }
300 command_put(cmd);
301
302 return len;
303 }
304
305 static ssize_t command_file_write(struct file *file, const char __user *ubuff, size_t count, loff_t *offset)
306 {
307 struct ibmasmfs_command_data *command_data = file->private_data;
308 struct command *cmd;
309 unsigned long flags;
310
311 if (*offset < 0)
312 return -EINVAL;
313 if (count == 0 || count > IBMASM_CMD_MAX_BUFFER_SIZE)
314 return 0;
315 if (*offset != 0)
316 return 0;
317
318 /* commands are executed sequentially, only one command at a time */
319 if (command_data->command)
320 return -EAGAIN;
321
322 cmd = ibmasm_new_command(command_data->sp, count);
323 if (!cmd)
324 return -ENOMEM;
325
326 if (copy_from_user(cmd->buffer, ubuff, count)) {
327 command_put(cmd);
328 return -EFAULT;
329 }
330
331 spin_lock_irqsave(&command_data->sp->lock, flags);
332 if (command_data->command) {
333 spin_unlock_irqrestore(&command_data->sp->lock, flags);
334 command_put(cmd);
335 return -EAGAIN;
336 }
337 command_data->command = cmd;
338 spin_unlock_irqrestore(&command_data->sp->lock, flags);
339
340 ibmasm_exec_command(command_data->sp, cmd);
341 ibmasm_wait_for_response(cmd, get_dot_command_timeout(cmd->buffer));
342
343 return count;
344 }
345
346 static int event_file_open(struct inode *inode, struct file *file)
347 {
348 struct ibmasmfs_event_data *event_data;
349 struct service_processor *sp;
350
351 if (!inode->i_private)
352 return -ENODEV;
353
354 sp = inode->i_private;
355
356 event_data = kmalloc(sizeof(struct ibmasmfs_event_data), GFP_KERNEL);
357 if (!event_data)
358 return -ENOMEM;
359
360 ibmasm_event_reader_register(sp, &event_data->reader);
361
362 event_data->sp = sp;
363 event_data->active = 0;
364 file->private_data = event_data;
365 return 0;
366 }
367
368 static int event_file_close(struct inode *inode, struct file *file)
369 {
370 struct ibmasmfs_event_data *event_data = file->private_data;
371
372 ibmasm_event_reader_unregister(event_data->sp, &event_data->reader);
373 kfree(event_data);
374 return 0;
375 }
376
377 static ssize_t event_file_read(struct file *file, char __user *buf, size_t count, loff_t *offset)
378 {
379 struct ibmasmfs_event_data *event_data = file->private_data;
380 struct event_reader *reader = &event_data->reader;
381 struct service_processor *sp = event_data->sp;
382 int ret;
383 unsigned long flags;
384
385 if (*offset < 0)
386 return -EINVAL;
387 if (count == 0 || count > IBMASM_EVENT_MAX_SIZE)
388 return 0;
389 if (*offset != 0)
390 return 0;
391
392 spin_lock_irqsave(&sp->lock, flags);
393 if (event_data->active) {
394 spin_unlock_irqrestore(&sp->lock, flags);
395 return -EBUSY;
396 }
397 event_data->active = 1;
398 spin_unlock_irqrestore(&sp->lock, flags);
399
400 ret = ibmasm_get_next_event(sp, reader);
401 if (ret <= 0)
402 goto out;
403
404 if (count < reader->data_size) {
405 ret = -EINVAL;
406 goto out;
407 }
408
409 if (copy_to_user(buf, reader->data, reader->data_size)) {
410 ret = -EFAULT;
411 goto out;
412 }
413 ret = reader->data_size;
414
415 out:
416 event_data->active = 0;
417 return ret;
418 }
419
420 static ssize_t event_file_write(struct file *file, const char __user *buf, size_t count, loff_t *offset)
421 {
422 struct ibmasmfs_event_data *event_data = file->private_data;
423
424 if (*offset < 0)
425 return -EINVAL;
426 if (count != 1)
427 return 0;
428 if (*offset != 0)
429 return 0;
430
431 ibmasm_cancel_next_event(&event_data->reader);
432 return 0;
433 }
434
435 static int r_heartbeat_file_open(struct inode *inode, struct file *file)
436 {
437 struct ibmasmfs_heartbeat_data *rhbeat;
438
439 if (!inode->i_private)
440 return -ENODEV;
441
442 rhbeat = kmalloc(sizeof(struct ibmasmfs_heartbeat_data), GFP_KERNEL);
443 if (!rhbeat)
444 return -ENOMEM;
445
446 rhbeat->sp = inode->i_private;
447 rhbeat->active = 0;
448 ibmasm_init_reverse_heartbeat(rhbeat->sp, &rhbeat->heartbeat);
449 file->private_data = rhbeat;
450 return 0;
451 }
452
453 static int r_heartbeat_file_close(struct inode *inode, struct file *file)
454 {
455 struct ibmasmfs_heartbeat_data *rhbeat = file->private_data;
456
457 kfree(rhbeat);
458 return 0;
459 }
460
461 static ssize_t r_heartbeat_file_read(struct file *file, char __user *buf, size_t count, loff_t *offset)
462 {
463 struct ibmasmfs_heartbeat_data *rhbeat = file->private_data;
464 unsigned long flags;
465 int result;
466
467 if (*offset < 0)
468 return -EINVAL;
469 if (count == 0 || count > 1024)
470 return 0;
471 if (*offset != 0)
472 return 0;
473
474 /* allow only one reverse heartbeat per process */
475 spin_lock_irqsave(&rhbeat->sp->lock, flags);
476 if (rhbeat->active) {
477 spin_unlock_irqrestore(&rhbeat->sp->lock, flags);
478 return -EBUSY;
479 }
480 rhbeat->active = 1;
481 spin_unlock_irqrestore(&rhbeat->sp->lock, flags);
482
483 result = ibmasm_start_reverse_heartbeat(rhbeat->sp, &rhbeat->heartbeat);
484 rhbeat->active = 0;
485
486 return result;
487 }
488
489 static ssize_t r_heartbeat_file_write(struct file *file, const char __user *buf, size_t count, loff_t *offset)
490 {
491 struct ibmasmfs_heartbeat_data *rhbeat = file->private_data;
492
493 if (*offset < 0)
494 return -EINVAL;
495 if (count != 1)
496 return 0;
497 if (*offset != 0)
498 return 0;
499
500 if (rhbeat->active)
501 ibmasm_stop_reverse_heartbeat(&rhbeat->heartbeat);
502
503 return 1;
504 }
505
506 static int remote_settings_file_open(struct inode *inode, struct file *file)
507 {
508 file->private_data = inode->i_private;
509 return 0;
510 }
511
512 static int remote_settings_file_close(struct inode *inode, struct file *file)
513 {
514 return 0;
515 }
516
517 static ssize_t remote_settings_file_read(struct file *file, char __user *buf, size_t count, loff_t *offset)
518 {
519 void __iomem *address = (void __iomem *)file->private_data;
520 unsigned char *page;
521 int retval;
522 int len = 0;
523 unsigned int value;
524
525 if (*offset < 0)
526 return -EINVAL;
527 if (count == 0 || count > 1024)
528 return 0;
529 if (*offset != 0)
530 return 0;
531
532 page = (unsigned char *)__get_free_page(GFP_KERNEL);
533 if (!page)
534 return -ENOMEM;
535
536 value = readl(address);
537 len = sprintf(page, "%d\n", value);
538
539 if (copy_to_user(buf, page, len)) {
540 retval = -EFAULT;
541 goto exit;
542 }
543 *offset += len;
544 retval = len;
545
546 exit:
547 free_page((unsigned long)page);
548 return retval;
549 }
550
551 static ssize_t remote_settings_file_write(struct file *file, const char __user *ubuff, size_t count, loff_t *offset)
552 {
553 void __iomem *address = (void __iomem *)file->private_data;
554 char *buff;
555 unsigned int value;
556
557 if (*offset < 0)
558 return -EINVAL;
559 if (count == 0 || count > 1024)
560 return 0;
561 if (*offset != 0)
562 return 0;
563
564 buff = kzalloc (count + 1, GFP_KERNEL);
565 if (!buff)
566 return -ENOMEM;
567
568
569 if (copy_from_user(buff, ubuff, count)) {
570 kfree(buff);
571 return -EFAULT;
572 }
573
574 value = simple_strtoul(buff, NULL, 10);
575 writel(value, address);
576 kfree(buff);
577
578 return count;
579 }
580
581 static const struct file_operations command_fops = {
582 .open = command_file_open,
583 .release = command_file_close,
584 .read = command_file_read,
585 .write = command_file_write,
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 };
594
595 static const struct file_operations r_heartbeat_fops = {
596 .open = r_heartbeat_file_open,
597 .release = r_heartbeat_file_close,
598 .read = r_heartbeat_file_read,
599 .write = r_heartbeat_file_write,
600 };
601
602 static const struct file_operations remote_settings_fops = {
603 .open = remote_settings_file_open,
604 .release = remote_settings_file_close,
605 .read = remote_settings_file_read,
606 .write = remote_settings_file_write,
607 };
608
609
610 static void ibmasmfs_create_files (struct super_block *sb, struct dentry *root)
611 {
612 struct list_head *entry;
613 struct service_processor *sp;
614
615 list_for_each(entry, &service_processors) {
616 struct dentry *dir;
617 struct dentry *remote_dir;
618 sp = list_entry(entry, struct service_processor, node);
619 dir = ibmasmfs_create_dir(sb, root, sp->dirname);
620 if (!dir)
621 continue;
622
623 ibmasmfs_create_file(sb, dir, "command", &command_fops, sp, S_IRUSR|S_IWUSR);
624 ibmasmfs_create_file(sb, dir, "event", &event_fops, sp, S_IRUSR|S_IWUSR);
625 ibmasmfs_create_file(sb, dir, "reverse_heartbeat", &r_heartbeat_fops, sp, S_IRUSR|S_IWUSR);
626
627 remote_dir = ibmasmfs_create_dir(sb, dir, "remote_video");
628 if (!remote_dir)
629 continue;
630
631 ibmasmfs_create_file(sb, remote_dir, "width", &remote_settings_fops, (void *)display_width(sp), S_IRUSR|S_IWUSR);
632 ibmasmfs_create_file(sb, remote_dir, "height", &remote_settings_fops, (void *)display_height(sp), S_IRUSR|S_IWUSR);
633 ibmasmfs_create_file(sb, remote_dir, "depth", &remote_settings_fops, (void *)display_depth(sp), S_IRUSR|S_IWUSR);
634 }
635 }
636
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