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 * | |-- 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
ibmasmfs_mount(struct file_system_type * fst,int flags,const char * name,void * data)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
ibmasmfs_fill_super(struct super_block * sb,void * data,int silent)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
ibmasmfs_make_inode(struct super_block * sb,int mode)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_ino = get_next_ino();
149 ret->i_mode = mode;
150 ret->i_atime = ret->i_mtime = ret->i_ctime = CURRENT_TIME;
151 }
152 return ret;
153 }
154
ibmasmfs_create_file(struct super_block * sb,struct dentry * parent,const char * name,const struct file_operations * fops,void * data,int mode)155 static struct dentry *ibmasmfs_create_file (struct super_block *sb,
156 struct dentry *parent,
157 const char *name,
158 const struct file_operations *fops,
159 void *data,
160 int mode)
161 {
162 struct dentry *dentry;
163 struct inode *inode;
164
165 dentry = d_alloc_name(parent, name);
166 if (!dentry)
167 return NULL;
168
169 inode = ibmasmfs_make_inode(sb, S_IFREG | mode);
170 if (!inode) {
171 dput(dentry);
172 return NULL;
173 }
174
175 inode->i_fop = fops;
176 inode->i_private = data;
177
178 d_add(dentry, inode);
179 return dentry;
180 }
181
ibmasmfs_create_dir(struct super_block * sb,struct dentry * parent,const char * name)182 static struct dentry *ibmasmfs_create_dir (struct super_block *sb,
183 struct dentry *parent,
184 const char *name)
185 {
186 struct dentry *dentry;
187 struct inode *inode;
188
189 dentry = d_alloc_name(parent, name);
190 if (!dentry)
191 return NULL;
192
193 inode = ibmasmfs_make_inode(sb, S_IFDIR | 0500);
194 if (!inode) {
195 dput(dentry);
196 return NULL;
197 }
198
199 inode->i_op = &simple_dir_inode_operations;
200 inode->i_fop = ibmasmfs_dir_ops;
201
202 d_add(dentry, inode);
203 return dentry;
204 }
205
ibmasmfs_register(void)206 int ibmasmfs_register(void)
207 {
208 return register_filesystem(&ibmasmfs_type);
209 }
210
ibmasmfs_unregister(void)211 void ibmasmfs_unregister(void)
212 {
213 unregister_filesystem(&ibmasmfs_type);
214 }
215
ibmasmfs_add_sp(struct service_processor * sp)216 void ibmasmfs_add_sp(struct service_processor *sp)
217 {
218 list_add(&sp->node, &service_processors);
219 }
220
221 /* struct to save state between command file operations */
222 struct ibmasmfs_command_data {
223 struct service_processor *sp;
224 struct command *command;
225 };
226
227 /* struct to save state between event file operations */
228 struct ibmasmfs_event_data {
229 struct service_processor *sp;
230 struct event_reader reader;
231 int active;
232 };
233
234 /* struct to save state between reverse heartbeat file operations */
235 struct ibmasmfs_heartbeat_data {
236 struct service_processor *sp;
237 struct reverse_heartbeat heartbeat;
238 int active;
239 };
240
command_file_open(struct inode * inode,struct file * file)241 static int command_file_open(struct inode *inode, struct file *file)
242 {
243 struct ibmasmfs_command_data *command_data;
244
245 if (!inode->i_private)
246 return -ENODEV;
247
248 command_data = kmalloc(sizeof(struct ibmasmfs_command_data), GFP_KERNEL);
249 if (!command_data)
250 return -ENOMEM;
251
252 command_data->command = NULL;
253 command_data->sp = inode->i_private;
254 file->private_data = command_data;
255 return 0;
256 }
257
command_file_close(struct inode * inode,struct file * file)258 static int command_file_close(struct inode *inode, struct file *file)
259 {
260 struct ibmasmfs_command_data *command_data = file->private_data;
261
262 if (command_data->command)
263 command_put(command_data->command);
264
265 kfree(command_data);
266 return 0;
267 }
268
command_file_read(struct file * file,char __user * buf,size_t count,loff_t * offset)269 static ssize_t command_file_read(struct file *file, char __user *buf, size_t count, loff_t *offset)
270 {
271 struct ibmasmfs_command_data *command_data = file->private_data;
272 struct command *cmd;
273 int len;
274 unsigned long flags;
275
276 if (*offset < 0)
277 return -EINVAL;
278 if (count == 0 || count > IBMASM_CMD_MAX_BUFFER_SIZE)
279 return 0;
280 if (*offset != 0)
281 return 0;
282
283 spin_lock_irqsave(&command_data->sp->lock, flags);
284 cmd = command_data->command;
285 if (cmd == NULL) {
286 spin_unlock_irqrestore(&command_data->sp->lock, flags);
287 return 0;
288 }
289 command_data->command = NULL;
290 spin_unlock_irqrestore(&command_data->sp->lock, flags);
291
292 if (cmd->status != IBMASM_CMD_COMPLETE) {
293 command_put(cmd);
294 return -EIO;
295 }
296 len = min(count, cmd->buffer_size);
297 if (copy_to_user(buf, cmd->buffer, len)) {
298 command_put(cmd);
299 return -EFAULT;
300 }
301 command_put(cmd);
302
303 return len;
304 }
305
command_file_write(struct file * file,const char __user * ubuff,size_t count,loff_t * offset)306 static ssize_t command_file_write(struct file *file, const char __user *ubuff, size_t count, loff_t *offset)
307 {
308 struct ibmasmfs_command_data *command_data = file->private_data;
309 struct command *cmd;
310 unsigned long flags;
311
312 if (*offset < 0)
313 return -EINVAL;
314 if (count == 0 || count > IBMASM_CMD_MAX_BUFFER_SIZE)
315 return 0;
316 if (*offset != 0)
317 return 0;
318
319 /* commands are executed sequentially, only one command at a time */
320 if (command_data->command)
321 return -EAGAIN;
322
323 cmd = ibmasm_new_command(command_data->sp, count);
324 if (!cmd)
325 return -ENOMEM;
326
327 if (copy_from_user(cmd->buffer, ubuff, count)) {
328 command_put(cmd);
329 return -EFAULT;
330 }
331
332 spin_lock_irqsave(&command_data->sp->lock, flags);
333 if (command_data->command) {
334 spin_unlock_irqrestore(&command_data->sp->lock, flags);
335 command_put(cmd);
336 return -EAGAIN;
337 }
338 command_data->command = cmd;
339 spin_unlock_irqrestore(&command_data->sp->lock, flags);
340
341 ibmasm_exec_command(command_data->sp, cmd);
342 ibmasm_wait_for_response(cmd, get_dot_command_timeout(cmd->buffer));
343
344 return count;
345 }
346
event_file_open(struct inode * inode,struct file * file)347 static int event_file_open(struct inode *inode, struct file *file)
348 {
349 struct ibmasmfs_event_data *event_data;
350 struct service_processor *sp;
351
352 if (!inode->i_private)
353 return -ENODEV;
354
355 sp = inode->i_private;
356
357 event_data = kmalloc(sizeof(struct ibmasmfs_event_data), GFP_KERNEL);
358 if (!event_data)
359 return -ENOMEM;
360
361 ibmasm_event_reader_register(sp, &event_data->reader);
362
363 event_data->sp = sp;
364 event_data->active = 0;
365 file->private_data = event_data;
366 return 0;
367 }
368
event_file_close(struct inode * inode,struct file * file)369 static int event_file_close(struct inode *inode, struct file *file)
370 {
371 struct ibmasmfs_event_data *event_data = file->private_data;
372
373 ibmasm_event_reader_unregister(event_data->sp, &event_data->reader);
374 kfree(event_data);
375 return 0;
376 }
377
event_file_read(struct file * file,char __user * buf,size_t count,loff_t * offset)378 static ssize_t event_file_read(struct file *file, char __user *buf, size_t count, loff_t *offset)
379 {
380 struct ibmasmfs_event_data *event_data = file->private_data;
381 struct event_reader *reader = &event_data->reader;
382 struct service_processor *sp = event_data->sp;
383 int ret;
384 unsigned long flags;
385
386 if (*offset < 0)
387 return -EINVAL;
388 if (count == 0 || count > IBMASM_EVENT_MAX_SIZE)
389 return 0;
390 if (*offset != 0)
391 return 0;
392
393 spin_lock_irqsave(&sp->lock, flags);
394 if (event_data->active) {
395 spin_unlock_irqrestore(&sp->lock, flags);
396 return -EBUSY;
397 }
398 event_data->active = 1;
399 spin_unlock_irqrestore(&sp->lock, flags);
400
401 ret = ibmasm_get_next_event(sp, reader);
402 if (ret <= 0)
403 goto out;
404
405 if (count < reader->data_size) {
406 ret = -EINVAL;
407 goto out;
408 }
409
410 if (copy_to_user(buf, reader->data, reader->data_size)) {
411 ret = -EFAULT;
412 goto out;
413 }
414 ret = reader->data_size;
415
416 out:
417 event_data->active = 0;
418 return ret;
419 }
420
event_file_write(struct file * file,const char __user * buf,size_t count,loff_t * offset)421 static ssize_t event_file_write(struct file *file, const char __user *buf, size_t count, loff_t *offset)
422 {
423 struct ibmasmfs_event_data *event_data = file->private_data;
424
425 if (*offset < 0)
426 return -EINVAL;
427 if (count != 1)
428 return 0;
429 if (*offset != 0)
430 return 0;
431
432 ibmasm_cancel_next_event(&event_data->reader);
433 return 0;
434 }
435
r_heartbeat_file_open(struct inode * inode,struct file * file)436 static int r_heartbeat_file_open(struct inode *inode, struct file *file)
437 {
438 struct ibmasmfs_heartbeat_data *rhbeat;
439
440 if (!inode->i_private)
441 return -ENODEV;
442
443 rhbeat = kmalloc(sizeof(struct ibmasmfs_heartbeat_data), GFP_KERNEL);
444 if (!rhbeat)
445 return -ENOMEM;
446
447 rhbeat->sp = inode->i_private;
448 rhbeat->active = 0;
449 ibmasm_init_reverse_heartbeat(rhbeat->sp, &rhbeat->heartbeat);
450 file->private_data = rhbeat;
451 return 0;
452 }
453
r_heartbeat_file_close(struct inode * inode,struct file * file)454 static int r_heartbeat_file_close(struct inode *inode, struct file *file)
455 {
456 struct ibmasmfs_heartbeat_data *rhbeat = file->private_data;
457
458 kfree(rhbeat);
459 return 0;
460 }
461
r_heartbeat_file_read(struct file * file,char __user * buf,size_t count,loff_t * offset)462 static ssize_t r_heartbeat_file_read(struct file *file, char __user *buf, size_t count, loff_t *offset)
463 {
464 struct ibmasmfs_heartbeat_data *rhbeat = file->private_data;
465 unsigned long flags;
466 int result;
467
468 if (*offset < 0)
469 return -EINVAL;
470 if (count == 0 || count > 1024)
471 return 0;
472 if (*offset != 0)
473 return 0;
474
475 /* allow only one reverse heartbeat per process */
476 spin_lock_irqsave(&rhbeat->sp->lock, flags);
477 if (rhbeat->active) {
478 spin_unlock_irqrestore(&rhbeat->sp->lock, flags);
479 return -EBUSY;
480 }
481 rhbeat->active = 1;
482 spin_unlock_irqrestore(&rhbeat->sp->lock, flags);
483
484 result = ibmasm_start_reverse_heartbeat(rhbeat->sp, &rhbeat->heartbeat);
485 rhbeat->active = 0;
486
487 return result;
488 }
489
r_heartbeat_file_write(struct file * file,const char __user * buf,size_t count,loff_t * offset)490 static ssize_t r_heartbeat_file_write(struct file *file, const char __user *buf, size_t count, loff_t *offset)
491 {
492 struct ibmasmfs_heartbeat_data *rhbeat = file->private_data;
493
494 if (*offset < 0)
495 return -EINVAL;
496 if (count != 1)
497 return 0;
498 if (*offset != 0)
499 return 0;
500
501 if (rhbeat->active)
502 ibmasm_stop_reverse_heartbeat(&rhbeat->heartbeat);
503
504 return 1;
505 }
506
remote_settings_file_open(struct inode * inode,struct file * file)507 static int remote_settings_file_open(struct inode *inode, struct file *file)
508 {
509 file->private_data = inode->i_private;
510 return 0;
511 }
512
remote_settings_file_close(struct inode * inode,struct file * file)513 static int remote_settings_file_close(struct inode *inode, struct file *file)
514 {
515 return 0;
516 }
517
remote_settings_file_read(struct file * file,char __user * buf,size_t count,loff_t * offset)518 static ssize_t remote_settings_file_read(struct file *file, char __user *buf, size_t count, loff_t *offset)
519 {
520 void __iomem *address = (void __iomem *)file->private_data;
521 unsigned char *page;
522 int retval;
523 int len = 0;
524 unsigned int value;
525
526 if (*offset < 0)
527 return -EINVAL;
528 if (count == 0 || count > 1024)
529 return 0;
530 if (*offset != 0)
531 return 0;
532
533 page = (unsigned char *)__get_free_page(GFP_KERNEL);
534 if (!page)
535 return -ENOMEM;
536
537 value = readl(address);
538 len = sprintf(page, "%d\n", value);
539
540 if (copy_to_user(buf, page, len)) {
541 retval = -EFAULT;
542 goto exit;
543 }
544 *offset += len;
545 retval = len;
546
547 exit:
548 free_page((unsigned long)page);
549 return retval;
550 }
551
remote_settings_file_write(struct file * file,const char __user * ubuff,size_t count,loff_t * offset)552 static ssize_t remote_settings_file_write(struct file *file, const char __user *ubuff, size_t count, loff_t *offset)
553 {
554 void __iomem *address = (void __iomem *)file->private_data;
555 char *buff;
556 unsigned int value;
557
558 if (*offset < 0)
559 return -EINVAL;
560 if (count == 0 || count > 1024)
561 return 0;
562 if (*offset != 0)
563 return 0;
564
565 buff = kzalloc (count + 1, GFP_KERNEL);
566 if (!buff)
567 return -ENOMEM;
568
569
570 if (copy_from_user(buff, ubuff, count)) {
571 kfree(buff);
572 return -EFAULT;
573 }
574
575 value = simple_strtoul(buff, NULL, 10);
576 writel(value, address);
577 kfree(buff);
578
579 return count;
580 }
581
582 static const struct file_operations command_fops = {
583 .open = command_file_open,
584 .release = command_file_close,
585 .read = command_file_read,
586 .write = command_file_write,
587 .llseek = generic_file_llseek,
588 };
589
590 static const struct file_operations event_fops = {
591 .open = event_file_open,
592 .release = event_file_close,
593 .read = event_file_read,
594 .write = event_file_write,
595 .llseek = generic_file_llseek,
596 };
597
598 static const struct file_operations r_heartbeat_fops = {
599 .open = r_heartbeat_file_open,
600 .release = r_heartbeat_file_close,
601 .read = r_heartbeat_file_read,
602 .write = r_heartbeat_file_write,
603 .llseek = generic_file_llseek,
604 };
605
606 static const struct file_operations remote_settings_fops = {
607 .open = remote_settings_file_open,
608 .release = remote_settings_file_close,
609 .read = remote_settings_file_read,
610 .write = remote_settings_file_write,
611 .llseek = generic_file_llseek,
612 };
613
614
ibmasmfs_create_files(struct super_block * sb,struct dentry * root)615 static void ibmasmfs_create_files (struct super_block *sb, struct dentry *root)
616 {
617 struct list_head *entry;
618 struct service_processor *sp;
619
620 list_for_each(entry, &service_processors) {
621 struct dentry *dir;
622 struct dentry *remote_dir;
623 sp = list_entry(entry, struct service_processor, node);
624 dir = ibmasmfs_create_dir(sb, root, sp->dirname);
625 if (!dir)
626 continue;
627
628 ibmasmfs_create_file(sb, dir, "command", &command_fops, sp, S_IRUSR|S_IWUSR);
629 ibmasmfs_create_file(sb, dir, "event", &event_fops, sp, S_IRUSR|S_IWUSR);
630 ibmasmfs_create_file(sb, dir, "reverse_heartbeat", &r_heartbeat_fops, sp, S_IRUSR|S_IWUSR);
631
632 remote_dir = ibmasmfs_create_dir(sb, dir, "remote_video");
633 if (!remote_dir)
634 continue;
635
636 ibmasmfs_create_file(sb, remote_dir, "width", &remote_settings_fops, (void *)display_width(sp), S_IRUSR|S_IWUSR);
637 ibmasmfs_create_file(sb, remote_dir, "height", &remote_settings_fops, (void *)display_height(sp), S_IRUSR|S_IWUSR);
638 ibmasmfs_create_file(sb, remote_dir, "depth", &remote_settings_fops, (void *)display_depth(sp), S_IRUSR|S_IWUSR);
639 }
640 }
641