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linux/drivers/misc/ibmasm/ibmasmfs.c
Arjan van de Ven d54b1fdb1d [PATCH] mark struct file_operations const 5
Many struct file_operations in the kernel can be "const".  Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data.  In addition it'll catch accidental writes at compile time to
these shared resources.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-12 09:48:45 -08:00

639 lines
15 KiB
C

/*
* IBM ASM Service Processor Device Driver
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
* Copyright (C) IBM Corporation, 2004
*
* Author: Max Asböck <amax@us.ibm.com>
*
*/
/*
* Parts of this code are based on an article by Jonathan Corbet
* that appeared in Linux Weekly News.
*/
/*
* The IBMASM file virtual filesystem. It creates the following hierarchy
* dymamically when mounted from user space:
*
* /ibmasm
* |-- 0
* | |-- command
* | |-- event
* | |-- reverse_heartbeat
* | `-- remote_video
* | |-- depth
* | |-- height
* | `-- width
* .
* .
* .
* `-- n
* |-- command
* |-- event
* |-- reverse_heartbeat
* `-- remote_video
* |-- depth
* |-- height
* `-- width
*
* For each service processor the following files are created:
*
* command: execute dot commands
* write: execute a dot command on the service processor
* read: return the result of a previously executed dot command
*
* events: listen for service processor events
* read: sleep (interruptible) until an event occurs
* write: wakeup sleeping event listener
*
* reverse_heartbeat: send a heartbeat to the service processor
* read: sleep (interruptible) until the reverse heartbeat fails
* write: wakeup sleeping heartbeat listener
*
* remote_video/width
* remote_video/height
* remote_video/width: control remote display settings
* write: set value
* read: read value
*/
#include <linux/fs.h>
#include <linux/pagemap.h>
#include <asm/uaccess.h>
#include <asm/io.h>
#include "ibmasm.h"
#include "remote.h"
#include "dot_command.h"
#define IBMASMFS_MAGIC 0x66726f67
static LIST_HEAD(service_processors);
static struct inode *ibmasmfs_make_inode(struct super_block *sb, int mode);
static void ibmasmfs_create_files (struct super_block *sb, struct dentry *root);
static int ibmasmfs_fill_super (struct super_block *sb, void *data, int silent);
static int ibmasmfs_get_super(struct file_system_type *fst,
int flags, const char *name, void *data,
struct vfsmount *mnt)
{
return get_sb_single(fst, flags, data, ibmasmfs_fill_super, mnt);
}
static struct super_operations ibmasmfs_s_ops = {
.statfs = simple_statfs,
.drop_inode = generic_delete_inode,
};
static const struct file_operations *ibmasmfs_dir_ops = &simple_dir_operations;
static struct file_system_type ibmasmfs_type = {
.owner = THIS_MODULE,
.name = "ibmasmfs",
.get_sb = ibmasmfs_get_super,
.kill_sb = kill_litter_super,
};
static int ibmasmfs_fill_super (struct super_block *sb, void *data, int silent)
{
struct inode *root;
struct dentry *root_dentry;
sb->s_blocksize = PAGE_CACHE_SIZE;
sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
sb->s_magic = IBMASMFS_MAGIC;
sb->s_op = &ibmasmfs_s_ops;
sb->s_time_gran = 1;
root = ibmasmfs_make_inode (sb, S_IFDIR | 0500);
if (!root)
return -ENOMEM;
root->i_op = &simple_dir_inode_operations;
root->i_fop = ibmasmfs_dir_ops;
root_dentry = d_alloc_root(root);
if (!root_dentry) {
iput(root);
return -ENOMEM;
}
sb->s_root = root_dentry;
ibmasmfs_create_files(sb, root_dentry);
return 0;
}
static struct inode *ibmasmfs_make_inode(struct super_block *sb, int mode)
{
struct inode *ret = new_inode(sb);
if (ret) {
ret->i_mode = mode;
ret->i_uid = ret->i_gid = 0;
ret->i_blocks = 0;
ret->i_atime = ret->i_mtime = ret->i_ctime = CURRENT_TIME;
}
return ret;
}
static struct dentry *ibmasmfs_create_file (struct super_block *sb,
struct dentry *parent,
const char *name,
const struct file_operations *fops,
void *data,
int mode)
{
struct dentry *dentry;
struct inode *inode;
dentry = d_alloc_name(parent, name);
if (!dentry)
return NULL;
inode = ibmasmfs_make_inode(sb, S_IFREG | mode);
if (!inode) {
dput(dentry);
return NULL;
}
inode->i_fop = fops;
inode->i_private = data;
d_add(dentry, inode);
return dentry;
}
static struct dentry *ibmasmfs_create_dir (struct super_block *sb,
struct dentry *parent,
const char *name)
{
struct dentry *dentry;
struct inode *inode;
dentry = d_alloc_name(parent, name);
if (!dentry)
return NULL;
inode = ibmasmfs_make_inode(sb, S_IFDIR | 0500);
if (!inode) {
dput(dentry);
return NULL;
}
inode->i_op = &simple_dir_inode_operations;
inode->i_fop = ibmasmfs_dir_ops;
d_add(dentry, inode);
return dentry;
}
int ibmasmfs_register(void)
{
return register_filesystem(&ibmasmfs_type);
}
void ibmasmfs_unregister(void)
{
unregister_filesystem(&ibmasmfs_type);
}
void ibmasmfs_add_sp(struct service_processor *sp)
{
list_add(&sp->node, &service_processors);
}
/* struct to save state between command file operations */
struct ibmasmfs_command_data {
struct service_processor *sp;
struct command *command;
};
/* struct to save state between event file operations */
struct ibmasmfs_event_data {
struct service_processor *sp;
struct event_reader reader;
int active;
};
/* struct to save state between reverse heartbeat file operations */
struct ibmasmfs_heartbeat_data {
struct service_processor *sp;
struct reverse_heartbeat heartbeat;
int active;
};
static int command_file_open(struct inode *inode, struct file *file)
{
struct ibmasmfs_command_data *command_data;
if (!inode->i_private)
return -ENODEV;
command_data = kmalloc(sizeof(struct ibmasmfs_command_data), GFP_KERNEL);
if (!command_data)
return -ENOMEM;
command_data->command = NULL;
command_data->sp = inode->i_private;
file->private_data = command_data;
return 0;
}
static int command_file_close(struct inode *inode, struct file *file)
{
struct ibmasmfs_command_data *command_data = file->private_data;
if (command_data->command)
command_put(command_data->command);
kfree(command_data);
return 0;
}
static ssize_t command_file_read(struct file *file, char __user *buf, size_t count, loff_t *offset)
{
struct ibmasmfs_command_data *command_data = file->private_data;
struct command *cmd;
int len;
unsigned long flags;
if (*offset < 0)
return -EINVAL;
if (count == 0 || count > IBMASM_CMD_MAX_BUFFER_SIZE)
return 0;
if (*offset != 0)
return 0;
spin_lock_irqsave(&command_data->sp->lock, flags);
cmd = command_data->command;
if (cmd == NULL) {
spin_unlock_irqrestore(&command_data->sp->lock, flags);
return 0;
}
command_data->command = NULL;
spin_unlock_irqrestore(&command_data->sp->lock, flags);
if (cmd->status != IBMASM_CMD_COMPLETE) {
command_put(cmd);
return -EIO;
}
len = min(count, cmd->buffer_size);
if (copy_to_user(buf, cmd->buffer, len)) {
command_put(cmd);
return -EFAULT;
}
command_put(cmd);
return len;
}
static ssize_t command_file_write(struct file *file, const char __user *ubuff, size_t count, loff_t *offset)
{
struct ibmasmfs_command_data *command_data = file->private_data;
struct command *cmd;
unsigned long flags;
if (*offset < 0)
return -EINVAL;
if (count == 0 || count > IBMASM_CMD_MAX_BUFFER_SIZE)
return 0;
if (*offset != 0)
return 0;
/* commands are executed sequentially, only one command at a time */
if (command_data->command)
return -EAGAIN;
cmd = ibmasm_new_command(command_data->sp, count);
if (!cmd)
return -ENOMEM;
if (copy_from_user(cmd->buffer, ubuff, count)) {
command_put(cmd);
return -EFAULT;
}
spin_lock_irqsave(&command_data->sp->lock, flags);
if (command_data->command) {
spin_unlock_irqrestore(&command_data->sp->lock, flags);
command_put(cmd);
return -EAGAIN;
}
command_data->command = cmd;
spin_unlock_irqrestore(&command_data->sp->lock, flags);
ibmasm_exec_command(command_data->sp, cmd);
ibmasm_wait_for_response(cmd, get_dot_command_timeout(cmd->buffer));
return count;
}
static int event_file_open(struct inode *inode, struct file *file)
{
struct ibmasmfs_event_data *event_data;
struct service_processor *sp;
if (!inode->i_private)
return -ENODEV;
sp = inode->i_private;
event_data = kmalloc(sizeof(struct ibmasmfs_event_data), GFP_KERNEL);
if (!event_data)
return -ENOMEM;
ibmasm_event_reader_register(sp, &event_data->reader);
event_data->sp = sp;
event_data->active = 0;
file->private_data = event_data;
return 0;
}
static int event_file_close(struct inode *inode, struct file *file)
{
struct ibmasmfs_event_data *event_data = file->private_data;
ibmasm_event_reader_unregister(event_data->sp, &event_data->reader);
kfree(event_data);
return 0;
}
static ssize_t event_file_read(struct file *file, char __user *buf, size_t count, loff_t *offset)
{
struct ibmasmfs_event_data *event_data = file->private_data;
struct event_reader *reader = &event_data->reader;
struct service_processor *sp = event_data->sp;
int ret;
unsigned long flags;
if (*offset < 0)
return -EINVAL;
if (count == 0 || count > IBMASM_EVENT_MAX_SIZE)
return 0;
if (*offset != 0)
return 0;
spin_lock_irqsave(&sp->lock, flags);
if (event_data->active) {
spin_unlock_irqrestore(&sp->lock, flags);
return -EBUSY;
}
event_data->active = 1;
spin_unlock_irqrestore(&sp->lock, flags);
ret = ibmasm_get_next_event(sp, reader);
if (ret <= 0)
goto out;
if (count < reader->data_size) {
ret = -EINVAL;
goto out;
}
if (copy_to_user(buf, reader->data, reader->data_size)) {
ret = -EFAULT;
goto out;
}
ret = reader->data_size;
out:
event_data->active = 0;
return ret;
}
static ssize_t event_file_write(struct file *file, const char __user *buf, size_t count, loff_t *offset)
{
struct ibmasmfs_event_data *event_data = file->private_data;
if (*offset < 0)
return -EINVAL;
if (count != 1)
return 0;
if (*offset != 0)
return 0;
ibmasm_cancel_next_event(&event_data->reader);
return 0;
}
static int r_heartbeat_file_open(struct inode *inode, struct file *file)
{
struct ibmasmfs_heartbeat_data *rhbeat;
if (!inode->i_private)
return -ENODEV;
rhbeat = kmalloc(sizeof(struct ibmasmfs_heartbeat_data), GFP_KERNEL);
if (!rhbeat)
return -ENOMEM;
rhbeat->sp = inode->i_private;
rhbeat->active = 0;
ibmasm_init_reverse_heartbeat(rhbeat->sp, &rhbeat->heartbeat);
file->private_data = rhbeat;
return 0;
}
static int r_heartbeat_file_close(struct inode *inode, struct file *file)
{
struct ibmasmfs_heartbeat_data *rhbeat = file->private_data;
kfree(rhbeat);
return 0;
}
static ssize_t r_heartbeat_file_read(struct file *file, char __user *buf, size_t count, loff_t *offset)
{
struct ibmasmfs_heartbeat_data *rhbeat = file->private_data;
unsigned long flags;
int result;
if (*offset < 0)
return -EINVAL;
if (count == 0 || count > 1024)
return 0;
if (*offset != 0)
return 0;
/* allow only one reverse heartbeat per process */
spin_lock_irqsave(&rhbeat->sp->lock, flags);
if (rhbeat->active) {
spin_unlock_irqrestore(&rhbeat->sp->lock, flags);
return -EBUSY;
}
rhbeat->active = 1;
spin_unlock_irqrestore(&rhbeat->sp->lock, flags);
result = ibmasm_start_reverse_heartbeat(rhbeat->sp, &rhbeat->heartbeat);
rhbeat->active = 0;
return result;
}
static ssize_t r_heartbeat_file_write(struct file *file, const char __user *buf, size_t count, loff_t *offset)
{
struct ibmasmfs_heartbeat_data *rhbeat = file->private_data;
if (*offset < 0)
return -EINVAL;
if (count != 1)
return 0;
if (*offset != 0)
return 0;
if (rhbeat->active)
ibmasm_stop_reverse_heartbeat(&rhbeat->heartbeat);
return 1;
}
static int remote_settings_file_open(struct inode *inode, struct file *file)
{
file->private_data = inode->i_private;
return 0;
}
static int remote_settings_file_close(struct inode *inode, struct file *file)
{
return 0;
}
static ssize_t remote_settings_file_read(struct file *file, char __user *buf, size_t count, loff_t *offset)
{
void __iomem *address = (void __iomem *)file->private_data;
unsigned char *page;
int retval;
int len = 0;
unsigned int value;
if (*offset < 0)
return -EINVAL;
if (count == 0 || count > 1024)
return 0;
if (*offset != 0)
return 0;
page = (unsigned char *)__get_free_page(GFP_KERNEL);
if (!page)
return -ENOMEM;
value = readl(address);
len = sprintf(page, "%d\n", value);
if (copy_to_user(buf, page, len)) {
retval = -EFAULT;
goto exit;
}
*offset += len;
retval = len;
exit:
free_page((unsigned long)page);
return retval;
}
static ssize_t remote_settings_file_write(struct file *file, const char __user *ubuff, size_t count, loff_t *offset)
{
void __iomem *address = (void __iomem *)file->private_data;
char *buff;
unsigned int value;
if (*offset < 0)
return -EINVAL;
if (count == 0 || count > 1024)
return 0;
if (*offset != 0)
return 0;
buff = kmalloc (count + 1, GFP_KERNEL);
if (!buff)
return -ENOMEM;
memset(buff, 0x0, count + 1);
if (copy_from_user(buff, ubuff, count)) {
kfree(buff);
return -EFAULT;
}
value = simple_strtoul(buff, NULL, 10);
writel(value, address);
kfree(buff);
return count;
}
static const struct file_operations command_fops = {
.open = command_file_open,
.release = command_file_close,
.read = command_file_read,
.write = command_file_write,
};
static const struct file_operations event_fops = {
.open = event_file_open,
.release = event_file_close,
.read = event_file_read,
.write = event_file_write,
};
static const struct file_operations r_heartbeat_fops = {
.open = r_heartbeat_file_open,
.release = r_heartbeat_file_close,
.read = r_heartbeat_file_read,
.write = r_heartbeat_file_write,
};
static const struct file_operations remote_settings_fops = {
.open = remote_settings_file_open,
.release = remote_settings_file_close,
.read = remote_settings_file_read,
.write = remote_settings_file_write,
};
static void ibmasmfs_create_files (struct super_block *sb, struct dentry *root)
{
struct list_head *entry;
struct service_processor *sp;
list_for_each(entry, &service_processors) {
struct dentry *dir;
struct dentry *remote_dir;
sp = list_entry(entry, struct service_processor, node);
dir = ibmasmfs_create_dir(sb, root, sp->dirname);
if (!dir)
continue;
ibmasmfs_create_file(sb, dir, "command", &command_fops, sp, S_IRUSR|S_IWUSR);
ibmasmfs_create_file(sb, dir, "event", &event_fops, sp, S_IRUSR|S_IWUSR);
ibmasmfs_create_file(sb, dir, "reverse_heartbeat", &r_heartbeat_fops, sp, S_IRUSR|S_IWUSR);
remote_dir = ibmasmfs_create_dir(sb, dir, "remote_video");
if (!remote_dir)
continue;
ibmasmfs_create_file(sb, remote_dir, "width", &remote_settings_fops, (void *)display_width(sp), S_IRUSR|S_IWUSR);
ibmasmfs_create_file(sb, remote_dir, "height", &remote_settings_fops, (void *)display_height(sp), S_IRUSR|S_IWUSR);
ibmasmfs_create_file(sb, remote_dir, "depth", &remote_settings_fops, (void *)display_depth(sp), S_IRUSR|S_IWUSR);
}
}