diff options
Diffstat (limited to 'drivers/misc/ibmasm/ibmasmfs.c')
| -rw-r--r-- | drivers/misc/ibmasm/ibmasmfs.c | 603 |
1 files changed, 603 insertions, 0 deletions
diff --git a/drivers/misc/ibmasm/ibmasmfs.c b/drivers/misc/ibmasm/ibmasmfs.c new file mode 100644 index 000000000..35fec1bf1 --- /dev/null +++ b/drivers/misc/ibmasm/ibmasmfs.c @@ -0,0 +1,603 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * IBM ASM Service Processor Device Driver + * + * 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 + * dynamically 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/fs_context.h> +#include <linux/pagemap.h> +#include <linux/slab.h> +#include <linux/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); +static int ibmasmfs_fill_super(struct super_block *sb, struct fs_context *fc); + +static int ibmasmfs_get_tree(struct fs_context *fc) +{ + return get_tree_single(fc, ibmasmfs_fill_super); +} + +static const struct fs_context_operations ibmasmfs_context_ops = { + .get_tree = ibmasmfs_get_tree, +}; + +static int ibmasmfs_init_fs_context(struct fs_context *fc) +{ + fc->ops = &ibmasmfs_context_ops; + return 0; +} + +static const 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", + .init_fs_context = ibmasmfs_init_fs_context, + .kill_sb = kill_litter_super, +}; +MODULE_ALIAS_FS("ibmasmfs"); + +static int ibmasmfs_fill_super(struct super_block *sb, struct fs_context *fc) +{ + struct inode *root; + + sb->s_blocksize = PAGE_SIZE; + sb->s_blocksize_bits = PAGE_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; + + sb->s_root = d_make_root(root); + if (!sb->s_root) + return -ENOMEM; + + ibmasmfs_create_files(sb); + return 0; +} + +static struct inode *ibmasmfs_make_inode(struct super_block *sb, int mode) +{ + struct inode *ret = new_inode(sb); + + if (ret) { + ret->i_ino = get_next_ino(); + ret->i_mode = mode; + ret->i_atime = ret->i_mtime = ret->i_ctime = current_time(ret); + } + return ret; +} + +static struct dentry *ibmasmfs_create_file(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(parent->d_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 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(parent->d_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_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; + int len = 0; + unsigned int value; + char lbuf[20]; + + value = readl(address); + len = snprintf(lbuf, sizeof(lbuf), "%d\n", value); + + return simple_read_from_buffer(buf, count, offset, lbuf, len); +} + +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 = kzalloc (count + 1, GFP_KERNEL); + if (!buff) + return -ENOMEM; + + + 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, + .llseek = generic_file_llseek, +}; + +static const struct file_operations event_fops = { + .open = event_file_open, + .release = event_file_close, + .read = event_file_read, + .write = event_file_write, + .llseek = generic_file_llseek, +}; + +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, + .llseek = generic_file_llseek, +}; + +static const struct file_operations remote_settings_fops = { + .open = simple_open, + .release = remote_settings_file_close, + .read = remote_settings_file_read, + .write = remote_settings_file_write, + .llseek = generic_file_llseek, +}; + + +static void ibmasmfs_create_files (struct super_block *sb) +{ + 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->s_root, sp->dirname); + if (!dir) + continue; + + ibmasmfs_create_file(dir, "command", &command_fops, sp, S_IRUSR|S_IWUSR); + ibmasmfs_create_file(dir, "event", &event_fops, sp, S_IRUSR|S_IWUSR); + ibmasmfs_create_file(dir, "reverse_heartbeat", &r_heartbeat_fops, sp, S_IRUSR|S_IWUSR); + + remote_dir = ibmasmfs_create_dir(dir, "remote_video"); + if (!remote_dir) + continue; + + ibmasmfs_create_file(remote_dir, "width", &remote_settings_fops, (void *)display_width(sp), S_IRUSR|S_IWUSR); + ibmasmfs_create_file(remote_dir, "height", &remote_settings_fops, (void *)display_height(sp), S_IRUSR|S_IWUSR); + ibmasmfs_create_file(remote_dir, "depth", &remote_settings_fops, (void *)display_depth(sp), S_IRUSR|S_IWUSR); + } +} |