2 * IBM ASM Service Processor Device Driver
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.
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.
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.
18 * Copyright (C) IBM Corporation, 2004
20 * Author: Max Asböck <amax@us.ibm.com>
25 * Parts of this code are based on an article by Jonathan Corbet
26 * that appeared in Linux Weekly News.
31 * The IBMASM file virtual filesystem. It creates the following hierarchy
32 * dynamically when mounted from user space:
38 * | |-- reverse_heartbeat
49 * |-- reverse_heartbeat
55 * For each service processor the following files are created:
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
61 * events: listen for service processor events
62 * read: sleep (interruptible) until an event occurs
63 * write: wakeup sleeping event listener
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
71 * remote_video/width: control remote display settings
77 #include <linux/pagemap.h>
78 #include <linux/slab.h>
79 #include <asm/uaccess.h>
83 #include "dot_command.h"
85 #define IBMASMFS_MAGIC 0x66726f67
87 static LIST_HEAD(service_processors);
89 static struct inode *ibmasmfs_make_inode(struct super_block *sb, int mode);
90 static void ibmasmfs_create_files (struct super_block *sb);
91 static int ibmasmfs_fill_super (struct super_block *sb, void *data, int silent);
94 static struct dentry *ibmasmfs_mount(struct file_system_type *fst,
95 int flags, const char *name, void *data)
97 return mount_single(fst, flags, data, ibmasmfs_fill_super);
100 static const struct super_operations ibmasmfs_s_ops = {
101 .statfs = simple_statfs,
102 .drop_inode = generic_delete_inode,
105 static const struct file_operations *ibmasmfs_dir_ops = &simple_dir_operations;
107 static struct file_system_type ibmasmfs_type = {
108 .owner = THIS_MODULE,
110 .mount = ibmasmfs_mount,
111 .kill_sb = kill_litter_super,
113 MODULE_ALIAS_FS("ibmasmfs");
115 static int ibmasmfs_fill_super (struct super_block *sb, void *data, int silent)
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;
125 root = ibmasmfs_make_inode (sb, S_IFDIR | 0500);
129 root->i_op = &simple_dir_inode_operations;
130 root->i_fop = ibmasmfs_dir_ops;
132 sb->s_root = d_make_root(root);
136 ibmasmfs_create_files(sb);
140 static struct inode *ibmasmfs_make_inode(struct super_block *sb, int mode)
142 struct inode *ret = new_inode(sb);
145 ret->i_ino = get_next_ino();
147 ret->i_atime = ret->i_mtime = ret->i_ctime = CURRENT_TIME;
152 static struct dentry *ibmasmfs_create_file (struct super_block *sb,
153 struct dentry *parent,
155 const struct file_operations *fops,
159 struct dentry *dentry;
162 dentry = d_alloc_name(parent, name);
166 inode = ibmasmfs_make_inode(sb, S_IFREG | mode);
173 inode->i_private = data;
175 d_add(dentry, inode);
179 static struct dentry *ibmasmfs_create_dir (struct super_block *sb,
180 struct dentry *parent,
183 struct dentry *dentry;
186 dentry = d_alloc_name(parent, name);
190 inode = ibmasmfs_make_inode(sb, S_IFDIR | 0500);
196 inode->i_op = &simple_dir_inode_operations;
197 inode->i_fop = ibmasmfs_dir_ops;
199 d_add(dentry, inode);
203 int ibmasmfs_register(void)
205 return register_filesystem(&ibmasmfs_type);
208 void ibmasmfs_unregister(void)
210 unregister_filesystem(&ibmasmfs_type);
213 void ibmasmfs_add_sp(struct service_processor *sp)
215 list_add(&sp->node, &service_processors);
218 /* struct to save state between command file operations */
219 struct ibmasmfs_command_data {
220 struct service_processor *sp;
221 struct command *command;
224 /* struct to save state between event file operations */
225 struct ibmasmfs_event_data {
226 struct service_processor *sp;
227 struct event_reader reader;
231 /* struct to save state between reverse heartbeat file operations */
232 struct ibmasmfs_heartbeat_data {
233 struct service_processor *sp;
234 struct reverse_heartbeat heartbeat;
238 static int command_file_open(struct inode *inode, struct file *file)
240 struct ibmasmfs_command_data *command_data;
242 if (!inode->i_private)
245 command_data = kmalloc(sizeof(struct ibmasmfs_command_data), GFP_KERNEL);
249 command_data->command = NULL;
250 command_data->sp = inode->i_private;
251 file->private_data = command_data;
255 static int command_file_close(struct inode *inode, struct file *file)
257 struct ibmasmfs_command_data *command_data = file->private_data;
259 if (command_data->command)
260 command_put(command_data->command);
266 static ssize_t command_file_read(struct file *file, char __user *buf, size_t count, loff_t *offset)
268 struct ibmasmfs_command_data *command_data = file->private_data;
275 if (count == 0 || count > IBMASM_CMD_MAX_BUFFER_SIZE)
280 spin_lock_irqsave(&command_data->sp->lock, flags);
281 cmd = command_data->command;
283 spin_unlock_irqrestore(&command_data->sp->lock, flags);
286 command_data->command = NULL;
287 spin_unlock_irqrestore(&command_data->sp->lock, flags);
289 if (cmd->status != IBMASM_CMD_COMPLETE) {
293 len = min(count, cmd->buffer_size);
294 if (copy_to_user(buf, cmd->buffer, len)) {
303 static ssize_t command_file_write(struct file *file, const char __user *ubuff, size_t count, loff_t *offset)
305 struct ibmasmfs_command_data *command_data = file->private_data;
311 if (count == 0 || count > IBMASM_CMD_MAX_BUFFER_SIZE)
316 /* commands are executed sequentially, only one command at a time */
317 if (command_data->command)
320 cmd = ibmasm_new_command(command_data->sp, count);
324 if (copy_from_user(cmd->buffer, ubuff, count)) {
329 spin_lock_irqsave(&command_data->sp->lock, flags);
330 if (command_data->command) {
331 spin_unlock_irqrestore(&command_data->sp->lock, flags);
335 command_data->command = cmd;
336 spin_unlock_irqrestore(&command_data->sp->lock, flags);
338 ibmasm_exec_command(command_data->sp, cmd);
339 ibmasm_wait_for_response(cmd, get_dot_command_timeout(cmd->buffer));
344 static int event_file_open(struct inode *inode, struct file *file)
346 struct ibmasmfs_event_data *event_data;
347 struct service_processor *sp;
349 if (!inode->i_private)
352 sp = inode->i_private;
354 event_data = kmalloc(sizeof(struct ibmasmfs_event_data), GFP_KERNEL);
358 ibmasm_event_reader_register(sp, &event_data->reader);
361 event_data->active = 0;
362 file->private_data = event_data;
366 static int event_file_close(struct inode *inode, struct file *file)
368 struct ibmasmfs_event_data *event_data = file->private_data;
370 ibmasm_event_reader_unregister(event_data->sp, &event_data->reader);
375 static ssize_t event_file_read(struct file *file, char __user *buf, size_t count, loff_t *offset)
377 struct ibmasmfs_event_data *event_data = file->private_data;
378 struct event_reader *reader = &event_data->reader;
379 struct service_processor *sp = event_data->sp;
385 if (count == 0 || count > IBMASM_EVENT_MAX_SIZE)
390 spin_lock_irqsave(&sp->lock, flags);
391 if (event_data->active) {
392 spin_unlock_irqrestore(&sp->lock, flags);
395 event_data->active = 1;
396 spin_unlock_irqrestore(&sp->lock, flags);
398 ret = ibmasm_get_next_event(sp, reader);
402 if (count < reader->data_size) {
407 if (copy_to_user(buf, reader->data, reader->data_size)) {
411 ret = reader->data_size;
414 event_data->active = 0;
418 static ssize_t event_file_write(struct file *file, const char __user *buf, size_t count, loff_t *offset)
420 struct ibmasmfs_event_data *event_data = file->private_data;
429 ibmasm_cancel_next_event(&event_data->reader);
433 static int r_heartbeat_file_open(struct inode *inode, struct file *file)
435 struct ibmasmfs_heartbeat_data *rhbeat;
437 if (!inode->i_private)
440 rhbeat = kmalloc(sizeof(struct ibmasmfs_heartbeat_data), GFP_KERNEL);
444 rhbeat->sp = inode->i_private;
446 ibmasm_init_reverse_heartbeat(rhbeat->sp, &rhbeat->heartbeat);
447 file->private_data = rhbeat;
451 static int r_heartbeat_file_close(struct inode *inode, struct file *file)
453 struct ibmasmfs_heartbeat_data *rhbeat = file->private_data;
459 static ssize_t r_heartbeat_file_read(struct file *file, char __user *buf, size_t count, loff_t *offset)
461 struct ibmasmfs_heartbeat_data *rhbeat = file->private_data;
467 if (count == 0 || count > 1024)
472 /* allow only one reverse heartbeat per process */
473 spin_lock_irqsave(&rhbeat->sp->lock, flags);
474 if (rhbeat->active) {
475 spin_unlock_irqrestore(&rhbeat->sp->lock, flags);
479 spin_unlock_irqrestore(&rhbeat->sp->lock, flags);
481 result = ibmasm_start_reverse_heartbeat(rhbeat->sp, &rhbeat->heartbeat);
487 static ssize_t r_heartbeat_file_write(struct file *file, const char __user *buf, size_t count, loff_t *offset)
489 struct ibmasmfs_heartbeat_data *rhbeat = file->private_data;
499 ibmasm_stop_reverse_heartbeat(&rhbeat->heartbeat);
504 static int remote_settings_file_close(struct inode *inode, struct file *file)
509 static ssize_t remote_settings_file_read(struct file *file, char __user *buf, size_t count, loff_t *offset)
511 void __iomem *address = (void __iomem *)file->private_data;
519 if (count == 0 || count > 1024)
524 page = (unsigned char *)__get_free_page(GFP_KERNEL);
528 value = readl(address);
529 len = sprintf(page, "%d\n", value);
531 if (copy_to_user(buf, page, len)) {
539 free_page((unsigned long)page);
543 static ssize_t remote_settings_file_write(struct file *file, const char __user *ubuff, size_t count, loff_t *offset)
545 void __iomem *address = (void __iomem *)file->private_data;
551 if (count == 0 || count > 1024)
556 buff = kzalloc (count + 1, GFP_KERNEL);
561 if (copy_from_user(buff, ubuff, count)) {
566 value = simple_strtoul(buff, NULL, 10);
567 writel(value, address);
573 static const struct file_operations command_fops = {
574 .open = command_file_open,
575 .release = command_file_close,
576 .read = command_file_read,
577 .write = command_file_write,
578 .llseek = generic_file_llseek,
581 static const struct file_operations event_fops = {
582 .open = event_file_open,
583 .release = event_file_close,
584 .read = event_file_read,
585 .write = event_file_write,
586 .llseek = generic_file_llseek,
589 static const struct file_operations r_heartbeat_fops = {
590 .open = r_heartbeat_file_open,
591 .release = r_heartbeat_file_close,
592 .read = r_heartbeat_file_read,
593 .write = r_heartbeat_file_write,
594 .llseek = generic_file_llseek,
597 static const struct file_operations remote_settings_fops = {
599 .release = remote_settings_file_close,
600 .read = remote_settings_file_read,
601 .write = remote_settings_file_write,
602 .llseek = generic_file_llseek,
606 static void ibmasmfs_create_files (struct super_block *sb)
608 struct list_head *entry;
609 struct service_processor *sp;
611 list_for_each(entry, &service_processors) {
613 struct dentry *remote_dir;
614 sp = list_entry(entry, struct service_processor, node);
615 dir = ibmasmfs_create_dir(sb, sb->s_root, sp->dirname);
619 ibmasmfs_create_file(sb, dir, "command", &command_fops, sp, S_IRUSR|S_IWUSR);
620 ibmasmfs_create_file(sb, dir, "event", &event_fops, sp, S_IRUSR|S_IWUSR);
621 ibmasmfs_create_file(sb, dir, "reverse_heartbeat", &r_heartbeat_fops, sp, S_IRUSR|S_IWUSR);
623 remote_dir = ibmasmfs_create_dir(sb, dir, "remote_video");
627 ibmasmfs_create_file(sb, remote_dir, "width", &remote_settings_fops, (void *)display_width(sp), S_IRUSR|S_IWUSR);
628 ibmasmfs_create_file(sb, remote_dir, "height", &remote_settings_fops, (void *)display_height(sp), S_IRUSR|S_IWUSR);
629 ibmasmfs_create_file(sb, remote_dir, "depth", &remote_settings_fops, (void *)display_depth(sp), S_IRUSR|S_IWUSR);