xref: /openbmc/linux/drivers/misc/ibmasm/ibmasmfs.c (revision 1da177e4)
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 Asb�ck <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  *    |       |-- connected
41  *    |       |-- depth
42  *    |       |-- events
43  *    |       |-- height
44  *    |       `-- width
45  *    .
46  *    .
47  *    .
48  *    `-- n
49  *        |-- command
50  *        |-- event
51  *        |-- reverse_heartbeat
52  *        `-- remote_video
53  *            |-- connected
54  *            |-- depth
55  *            |-- events
56  *            |-- height
57  *            `-- width
58  *
59  * For each service processor the following files are created:
60  *
61  * command: execute dot commands
62  * 	write: execute a dot command on the service processor
63  * 	read: return the result of a previously executed dot command
64  *
65  * events: listen for service processor events
66  * 	read: sleep (interruptible) until an event occurs
67  *      write: wakeup sleeping event listener
68  *
69  * reverse_heartbeat: send a heartbeat to the service processor
70  * 	read: sleep (interruptible) until the reverse heartbeat fails
71  *      write: wakeup sleeping heartbeat listener
72  *
73  * remote_video/width
74  * remote_video/height
75  * remote_video/width: control remote display settings
76  * 	write: set value
77  * 	read: read value
78  *
79  * remote_video/connected
80  * 	read: return "1" if web browser VNC java applet is connected,
81  * 		"0" otherwise
82  *
83  * remote_video/events
84  * 	read: sleep until a remote mouse or keyboard event occurs, then return
85  * 		then event.
86  */
87 
88 #include <linux/fs.h>
89 #include <linux/pagemap.h>
90 #include <asm/uaccess.h>
91 #include <asm/io.h>
92 #include "ibmasm.h"
93 #include "remote.h"
94 #include "dot_command.h"
95 
96 #define IBMASMFS_MAGIC 0x66726f67
97 
98 static LIST_HEAD(service_processors);
99 
100 static struct inode *ibmasmfs_make_inode(struct super_block *sb, int mode);
101 static void ibmasmfs_create_files (struct super_block *sb, struct dentry *root);
102 static int ibmasmfs_fill_super (struct super_block *sb, void *data, int silent);
103 
104 
105 static struct super_block *ibmasmfs_get_super(struct file_system_type *fst,
106 			int flags, const char *name, void *data)
107 {
108 	return get_sb_single(fst, flags, data, ibmasmfs_fill_super);
109 }
110 
111 static struct super_operations ibmasmfs_s_ops = {
112 	.statfs		= simple_statfs,
113 	.drop_inode	= generic_delete_inode,
114 };
115 
116 static struct file_operations *ibmasmfs_dir_ops = &simple_dir_operations;
117 
118 static struct file_system_type ibmasmfs_type = {
119 	.owner          = THIS_MODULE,
120 	.name           = "ibmasmfs",
121 	.get_sb         = ibmasmfs_get_super,
122 	.kill_sb        = kill_litter_super,
123 };
124 
125 static int ibmasmfs_fill_super (struct super_block *sb, void *data, int silent)
126 {
127 	struct inode *root;
128 	struct dentry *root_dentry;
129 
130 	sb->s_blocksize = PAGE_CACHE_SIZE;
131 	sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
132 	sb->s_magic = IBMASMFS_MAGIC;
133 	sb->s_op = &ibmasmfs_s_ops;
134 	sb->s_time_gran = 1;
135 
136 	root = ibmasmfs_make_inode (sb, S_IFDIR | 0500);
137 	if (!root)
138 		return -ENOMEM;
139 
140 	root->i_op = &simple_dir_inode_operations;
141 	root->i_fop = ibmasmfs_dir_ops;
142 
143 	root_dentry = d_alloc_root(root);
144 	if (!root_dentry) {
145 		iput(root);
146 		return -ENOMEM;
147 	}
148 	sb->s_root = root_dentry;
149 
150 	ibmasmfs_create_files(sb, root_dentry);
151 	return 0;
152 }
153 
154 static struct inode *ibmasmfs_make_inode(struct super_block *sb, int mode)
155 {
156 	struct inode *ret = new_inode(sb);
157 
158 	if (ret) {
159 		ret->i_mode = mode;
160 		ret->i_uid = ret->i_gid = 0;
161 		ret->i_blksize = PAGE_CACHE_SIZE;
162 		ret->i_blocks = 0;
163 		ret->i_atime = ret->i_mtime = ret->i_ctime = CURRENT_TIME;
164 	}
165 	return ret;
166 }
167 
168 static struct dentry *ibmasmfs_create_file (struct super_block *sb,
169 			struct dentry *parent,
170 		       	const char *name,
171 			struct file_operations *fops,
172 			void *data,
173 			int mode)
174 {
175 	struct dentry *dentry;
176 	struct inode *inode;
177 
178 	dentry = d_alloc_name(parent, name);
179 	if (!dentry)
180 		return NULL;
181 
182 	inode = ibmasmfs_make_inode(sb, S_IFREG | mode);
183 	if (!inode) {
184 		dput(dentry);
185 		return NULL;
186 	}
187 
188 	inode->i_fop = fops;
189 	inode->u.generic_ip = data;
190 
191 	d_add(dentry, inode);
192 	return dentry;
193 }
194 
195 static struct dentry *ibmasmfs_create_dir (struct super_block *sb,
196 				struct dentry *parent,
197 				const char *name)
198 {
199 	struct dentry *dentry;
200 	struct inode *inode;
201 
202 	dentry = d_alloc_name(parent, name);
203 	if (!dentry)
204 		return NULL;
205 
206 	inode = ibmasmfs_make_inode(sb, S_IFDIR | 0500);
207 	if (!inode) {
208 		dput(dentry);
209 		return NULL;
210 	}
211 
212 	inode->i_op = &simple_dir_inode_operations;
213 	inode->i_fop = ibmasmfs_dir_ops;
214 
215 	d_add(dentry, inode);
216 	return dentry;
217 }
218 
219 int ibmasmfs_register(void)
220 {
221 	return register_filesystem(&ibmasmfs_type);
222 }
223 
224 void ibmasmfs_unregister(void)
225 {
226 	unregister_filesystem(&ibmasmfs_type);
227 }
228 
229 void ibmasmfs_add_sp(struct service_processor *sp)
230 {
231 	list_add(&sp->node, &service_processors);
232 }
233 
234 /* struct to save state between command file operations */
235 struct ibmasmfs_command_data {
236 	struct service_processor	*sp;
237 	struct command			*command;
238 };
239 
240 /* struct to save state between event file operations */
241 struct ibmasmfs_event_data {
242 	struct service_processor	*sp;
243 	struct event_reader		reader;
244 	int				active;
245 };
246 
247 /* struct to save state between reverse heartbeat file operations */
248 struct ibmasmfs_heartbeat_data {
249 	struct service_processor	*sp;
250 	struct reverse_heartbeat	heartbeat;
251 	int				active;
252 };
253 
254 static int command_file_open(struct inode *inode, struct file *file)
255 {
256 	struct ibmasmfs_command_data *command_data;
257 
258 	if (!inode->u.generic_ip)
259 		return -ENODEV;
260 
261 	command_data = kmalloc(sizeof(struct ibmasmfs_command_data), GFP_KERNEL);
262 	if (!command_data)
263 		return -ENOMEM;
264 
265 	command_data->command = NULL;
266 	command_data->sp = inode->u.generic_ip;
267 	file->private_data = command_data;
268 	return 0;
269 }
270 
271 static int command_file_close(struct inode *inode, struct file *file)
272 {
273 	struct ibmasmfs_command_data *command_data = file->private_data;
274 
275 	if (command_data->command)
276 		command_put(command_data->command);
277 
278 	kfree(command_data);
279 	return 0;
280 }
281 
282 static ssize_t command_file_read(struct file *file, char __user *buf, size_t count, loff_t *offset)
283 {
284 	struct ibmasmfs_command_data *command_data = file->private_data;
285 	struct command *cmd;
286 	int len;
287 	unsigned long flags;
288 
289 	if (*offset < 0)
290 		return -EINVAL;
291 	if (count == 0 || count > IBMASM_CMD_MAX_BUFFER_SIZE)
292 		return 0;
293 	if (*offset != 0)
294 		return 0;
295 
296 	spin_lock_irqsave(&command_data->sp->lock, flags);
297 	cmd = command_data->command;
298 	if (cmd == NULL) {
299 		spin_unlock_irqrestore(&command_data->sp->lock, flags);
300 		return 0;
301 	}
302 	command_data->command = NULL;
303 	spin_unlock_irqrestore(&command_data->sp->lock, flags);
304 
305 	if (cmd->status != IBMASM_CMD_COMPLETE) {
306 		command_put(cmd);
307 		return -EIO;
308 	}
309 	len = min(count, cmd->buffer_size);
310 	if (copy_to_user(buf, cmd->buffer, len)) {
311 		command_put(cmd);
312 		return -EFAULT;
313 	}
314 	command_put(cmd);
315 
316 	return len;
317 }
318 
319 static ssize_t command_file_write(struct file *file, const char __user *ubuff, size_t count, loff_t *offset)
320 {
321 	struct ibmasmfs_command_data *command_data = file->private_data;
322 	struct command *cmd;
323 	unsigned long flags;
324 
325 	if (*offset < 0)
326 		return -EINVAL;
327 	if (count == 0 || count > IBMASM_CMD_MAX_BUFFER_SIZE)
328 		return 0;
329 	if (*offset != 0)
330 		return 0;
331 
332 	/* commands are executed sequentially, only one command at a time */
333 	if (command_data->command)
334 		return -EAGAIN;
335 
336 	cmd = ibmasm_new_command(count);
337 	if (!cmd)
338 		return -ENOMEM;
339 
340 	if (copy_from_user(cmd->buffer, ubuff, count)) {
341 		command_put(cmd);
342 		return -EFAULT;
343 	}
344 
345 	spin_lock_irqsave(&command_data->sp->lock, flags);
346 	if (command_data->command) {
347 		spin_unlock_irqrestore(&command_data->sp->lock, flags);
348 		command_put(cmd);
349 		return -EAGAIN;
350 	}
351 	command_data->command = cmd;
352 	spin_unlock_irqrestore(&command_data->sp->lock, flags);
353 
354 	ibmasm_exec_command(command_data->sp, cmd);
355 	ibmasm_wait_for_response(cmd, get_dot_command_timeout(cmd->buffer));
356 
357 	return count;
358 }
359 
360 static int event_file_open(struct inode *inode, struct file *file)
361 {
362 	struct ibmasmfs_event_data *event_data;
363 	struct service_processor *sp;
364 
365 	if (!inode->u.generic_ip)
366 		return -ENODEV;
367 
368 	sp = inode->u.generic_ip;
369 
370 	event_data = kmalloc(sizeof(struct ibmasmfs_event_data), GFP_KERNEL);
371 	if (!event_data)
372 		return -ENOMEM;
373 
374 	ibmasm_event_reader_register(sp, &event_data->reader);
375 
376 	event_data->sp = sp;
377 	file->private_data = event_data;
378 	return 0;
379 }
380 
381 static int event_file_close(struct inode *inode, struct file *file)
382 {
383 	struct ibmasmfs_event_data *event_data = file->private_data;
384 
385 	ibmasm_event_reader_unregister(event_data->sp, &event_data->reader);
386 	kfree(event_data);
387 	return 0;
388 }
389 
390 static ssize_t event_file_read(struct file *file, char __user *buf, size_t count, loff_t *offset)
391 {
392 	struct ibmasmfs_event_data *event_data = file->private_data;
393 	struct event_reader *reader = &event_data->reader;
394 	int ret;
395 
396 	if (*offset < 0)
397 		return -EINVAL;
398 	if (count == 0 || count > IBMASM_EVENT_MAX_SIZE)
399 		return 0;
400 	if (*offset != 0)
401 		return 0;
402 
403 	ret = ibmasm_get_next_event(event_data->sp, reader);
404 	if (ret <= 0)
405 		return ret;
406 
407 	if (count < reader->data_size)
408 		return -EINVAL;
409 
410         if (copy_to_user(buf, reader->data, reader->data_size))
411 		return -EFAULT;
412 
413 	return reader->data_size;
414 }
415 
416 static ssize_t event_file_write(struct file *file, const char __user *buf, size_t count, loff_t *offset)
417 {
418 	struct ibmasmfs_event_data *event_data = file->private_data;
419 
420 	if (*offset < 0)
421 		return -EINVAL;
422 	if (count != 1)
423 		return 0;
424 	if (*offset != 0)
425 		return 0;
426 
427 	wake_up_interruptible(&event_data->reader.wait);
428 	return 0;
429 }
430 
431 static int r_heartbeat_file_open(struct inode *inode, struct file *file)
432 {
433 	struct ibmasmfs_heartbeat_data *rhbeat;
434 
435 	if (!inode->u.generic_ip)
436 		return -ENODEV;
437 
438 	rhbeat = kmalloc(sizeof(struct ibmasmfs_heartbeat_data), GFP_KERNEL);
439 	if (!rhbeat)
440 		return -ENOMEM;
441 
442 	rhbeat->sp = (struct service_processor *)inode->u.generic_ip;
443 	rhbeat->active = 0;
444 	ibmasm_init_reverse_heartbeat(rhbeat->sp, &rhbeat->heartbeat);
445 	file->private_data = rhbeat;
446 	return 0;
447 }
448 
449 static int r_heartbeat_file_close(struct inode *inode, struct file *file)
450 {
451 	struct ibmasmfs_heartbeat_data *rhbeat = file->private_data;
452 
453 	kfree(rhbeat);
454 	return 0;
455 }
456 
457 static ssize_t r_heartbeat_file_read(struct file *file, char __user *buf, size_t count, loff_t *offset)
458 {
459 	struct ibmasmfs_heartbeat_data *rhbeat = file->private_data;
460 	unsigned long flags;
461 	int result;
462 
463 	if (*offset < 0)
464 		return -EINVAL;
465 	if (count == 0 || count > 1024)
466 		return 0;
467 	if (*offset != 0)
468 		return 0;
469 
470 	/* allow only one reverse heartbeat per process */
471 	spin_lock_irqsave(&rhbeat->sp->lock, flags);
472 	if (rhbeat->active) {
473 		spin_unlock_irqrestore(&rhbeat->sp->lock, flags);
474 		return -EBUSY;
475 	}
476 	rhbeat->active = 1;
477 	spin_unlock_irqrestore(&rhbeat->sp->lock, flags);
478 
479 	result = ibmasm_start_reverse_heartbeat(rhbeat->sp, &rhbeat->heartbeat);
480 	rhbeat->active = 0;
481 
482 	return result;
483 }
484 
485 static ssize_t r_heartbeat_file_write(struct file *file, const char __user *buf, size_t count, loff_t *offset)
486 {
487 	struct ibmasmfs_heartbeat_data *rhbeat = file->private_data;
488 
489 	if (*offset < 0)
490 		return -EINVAL;
491 	if (count != 1)
492 		return 0;
493 	if (*offset != 0)
494 		return 0;
495 
496 	if (rhbeat->active)
497 		ibmasm_stop_reverse_heartbeat(&rhbeat->heartbeat);
498 
499 	return 1;
500 }
501 
502 static int remote_settings_file_open(struct inode *inode, struct file *file)
503 {
504 	file->private_data = inode->u.generic_ip;
505 	return 0;
506 }
507 
508 static int remote_settings_file_close(struct inode *inode, struct file *file)
509 {
510 	return 0;
511 }
512 
513 static ssize_t remote_settings_file_read(struct file *file, char __user *buf, size_t count, loff_t *offset)
514 {
515 	void __iomem *address = (void __iomem *)file->private_data;
516 	unsigned char *page;
517 	int retval;
518 	int len = 0;
519 	unsigned int value;
520 
521 	if (*offset < 0)
522 		return -EINVAL;
523 	if (count == 0 || count > 1024)
524 		return 0;
525 	if (*offset != 0)
526 		return 0;
527 
528 	page = (unsigned char *)__get_free_page(GFP_KERNEL);
529 	if (!page)
530 		return -ENOMEM;
531 
532 	value = readl(address);
533 	len = sprintf(page, "%d\n", value);
534 
535 	if (copy_to_user(buf, page, len)) {
536 		retval = -EFAULT;
537 		goto exit;
538 	}
539 	*offset += len;
540 	retval = len;
541 
542 exit:
543 	free_page((unsigned long)page);
544 	return retval;
545 }
546 
547 static ssize_t remote_settings_file_write(struct file *file, const char __user *ubuff, size_t count, loff_t *offset)
548 {
549 	void __iomem *address = (void __iomem *)file->private_data;
550 	char *buff;
551 	unsigned int value;
552 
553 	if (*offset < 0)
554 		return -EINVAL;
555 	if (count == 0 || count > 1024)
556 		return 0;
557 	if (*offset != 0)
558 		return 0;
559 
560 	buff = kmalloc (count + 1, GFP_KERNEL);
561 	if (!buff)
562 		return -ENOMEM;
563 
564 	memset(buff, 0x0, count + 1);
565 
566 	if (copy_from_user(buff, ubuff, count)) {
567 		kfree(buff);
568 		return -EFAULT;
569 	}
570 
571 	value = simple_strtoul(buff, NULL, 10);
572 	writel(value, address);
573 	kfree(buff);
574 
575 	return count;
576 }
577 
578 static int remote_event_file_open(struct inode *inode, struct file *file)
579 {
580 	struct service_processor *sp;
581 	unsigned long flags;
582 	struct remote_queue *q;
583 
584 	file->private_data = inode->u.generic_ip;
585 	sp = file->private_data;
586 	q = &sp->remote_queue;
587 
588 	/* allow only one event reader */
589 	spin_lock_irqsave(&sp->lock, flags);
590 	if (q->open) {
591 		spin_unlock_irqrestore(&sp->lock, flags);
592 		return -EBUSY;
593 	}
594 	q->open = 1;
595 	spin_unlock_irqrestore(&sp->lock, flags);
596 
597 	enable_mouse_interrupts(sp);
598 
599 	return 0;
600 }
601 
602 static int remote_event_file_close(struct inode *inode, struct file *file)
603 {
604 	struct service_processor *sp = file->private_data;
605 
606 	disable_mouse_interrupts(sp);
607 	wake_up_interruptible(&sp->remote_queue.wait);
608 	sp->remote_queue.open = 0;
609 
610 	return 0;
611 }
612 
613 static ssize_t remote_event_file_read(struct file *file, char __user *buf, size_t count, loff_t *offset)
614 {
615 	struct service_processor *sp = file->private_data;
616 	struct remote_queue *q = &sp->remote_queue;
617 	size_t data_size;
618 	struct remote_event *reader = q->reader;
619 	size_t num_events;
620 
621 	if (*offset < 0)
622 		return -EINVAL;
623 	if (count == 0 || count > 1024)
624 		return 0;
625 	if (*offset != 0)
626 		return 0;
627 
628 	if (wait_event_interruptible(q->wait, q->reader != q->writer))
629 		return -ERESTARTSYS;
630 
631 	/* only get multiples of struct remote_event */
632 	num_events = min((count/sizeof(struct remote_event)), ibmasm_events_available(q));
633 	if (!num_events)
634 		return 0;
635 
636 	data_size = num_events * sizeof(struct remote_event);
637 
638 	if (copy_to_user(buf, reader, data_size))
639 		return -EFAULT;
640 
641 	ibmasm_advance_reader(q, num_events);
642 
643 	return data_size;
644 }
645 
646 
647 static struct file_operations command_fops = {
648 	.open =		command_file_open,
649 	.release =	command_file_close,
650 	.read =		command_file_read,
651 	.write =	command_file_write,
652 };
653 
654 static struct file_operations event_fops = {
655 	.open =		event_file_open,
656 	.release =	event_file_close,
657 	.read =		event_file_read,
658 	.write =	event_file_write,
659 };
660 
661 static struct file_operations r_heartbeat_fops = {
662 	.open =		r_heartbeat_file_open,
663 	.release =	r_heartbeat_file_close,
664 	.read =		r_heartbeat_file_read,
665 	.write =	r_heartbeat_file_write,
666 };
667 
668 static struct file_operations remote_settings_fops = {
669 	.open =		remote_settings_file_open,
670 	.release =	remote_settings_file_close,
671 	.read =		remote_settings_file_read,
672 	.write =	remote_settings_file_write,
673 };
674 
675 static struct file_operations remote_event_fops = {
676 	.open =		remote_event_file_open,
677 	.release =	remote_event_file_close,
678 	.read =		remote_event_file_read,
679 };
680 
681 
682 static void ibmasmfs_create_files (struct super_block *sb, struct dentry *root)
683 {
684 	struct list_head *entry;
685 	struct service_processor *sp;
686 
687 	list_for_each(entry, &service_processors) {
688 		struct dentry *dir;
689 		struct dentry *remote_dir;
690 		sp = list_entry(entry, struct service_processor, node);
691 		dir = ibmasmfs_create_dir(sb, root, sp->dirname);
692 		if (!dir)
693 			continue;
694 
695 		ibmasmfs_create_file(sb, dir, "command", &command_fops, sp, S_IRUSR|S_IWUSR);
696 		ibmasmfs_create_file(sb, dir, "event", &event_fops, sp, S_IRUSR|S_IWUSR);
697 		ibmasmfs_create_file(sb, dir, "reverse_heartbeat", &r_heartbeat_fops, sp, S_IRUSR|S_IWUSR);
698 
699 		remote_dir = ibmasmfs_create_dir(sb, dir, "remote_video");
700 		if (!remote_dir)
701 			continue;
702 
703 		ibmasmfs_create_file(sb, remote_dir, "width", &remote_settings_fops, (void *)display_width(sp), S_IRUSR|S_IWUSR);
704 		ibmasmfs_create_file(sb, remote_dir, "height", &remote_settings_fops, (void *)display_height(sp), S_IRUSR|S_IWUSR);
705 		ibmasmfs_create_file(sb, remote_dir, "depth", &remote_settings_fops, (void *)display_depth(sp), S_IRUSR|S_IWUSR);
706 		ibmasmfs_create_file(sb, remote_dir, "connected", &remote_settings_fops, (void *)vnc_status(sp), S_IRUSR);
707 		ibmasmfs_create_file(sb, remote_dir, "events", &remote_event_fops, (void *)sp, S_IRUSR);
708 	}
709 }
710