[PATCH] Driver for IBM service processor - updated (2/2)

Here is the filesystem part for the IBM RSA service processor device driver

drivers/misc/ibmasm/ibmasmfs.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 Asbck <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
+ *    |       |-- connected
+ *    |       |-- depth
+ *    |       |-- events
+ *    |       |-- height
+ *    |       `-- width
+ *    .
+ *    .
+ *    .
+ *    `-- n
+ *        |-- command
+ *        |-- event
+ *        |-- reverse_heartbeat
+ *        `-- remote_video
+ *            |-- connected
+ *            |-- depth
+ *            |-- events
+ *            |-- 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
+ *
+ * remote_video/connected
+ * 	read: return "1" if web browser VNC java applet is connected, 
+ * 		"0" otherwise
+ *
+ * remote_video/events
+ * 	read: sleep until a remote mouse or keyboard event occurs, then return
+ * 		then event.
+ */
+
+#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 struct super_block *ibmasmfs_get_super(struct file_system_type *fst,
+			int flags, const char *name, void *data)
+{
+	return get_sb_single(fst, flags, data, ibmasmfs_fill_super);
+}
+
+static struct super_operations ibmasmfs_s_ops = {
+	.statfs		= simple_statfs,
+	.drop_inode	= generic_delete_inode,
+};
+
+static 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;
+
+	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_blksize = PAGE_CACHE_SIZE;
+		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,
+			struct file_operations *fops,
+			void *data,
+			int mode)
+{
+	struct dentry *dentry;
+	struct inode *inode;
+	struct qstr qname;
+
+	qname.name = name;
+	qname.len = strlen (name);
+	qname.hash = full_name_hash(name, qname.len);
+
+	dentry = d_alloc(parent, &qname);
+	if (!dentry)
+		return NULL;
+
+	inode = ibmasmfs_make_inode(sb, S_IFREG | mode);
+	if (!inode) {
+		dput(dentry);
+		return NULL;
+	}
+
+	inode->i_fop = fops;
+	inode->u.generic_ip = 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;
+	struct qstr qname;
+
+	qname.name = name;
+	qname.len = strlen (name);
+	qname.hash = full_name_hash(name, qname.len);
+	dentry = d_alloc(parent, &qname);
+	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()
+{
+	return register_filesystem(&ibmasmfs_type);
+}
+
+void ibmasmfs_unregister()
+{
+	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->u.generic_ip)
+		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->u.generic_ip;
+	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 *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 *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(count);
+	if (!cmd)
+		return -ENOMEM;
+
+	if (copy_from_user((void *)cmd->buffer, (void *)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->u.generic_ip)
+		return -ENODEV;
+
+	sp = inode->u.generic_ip;
+
+	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;
+	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 *buf, size_t count, loff_t *offset)
+{
+	struct ibmasmfs_event_data *event_data = file->private_data;
+	struct event_reader *reader = &event_data->reader;
+	int ret;
+
+	if (*offset < 0)
+		return -EINVAL;
+	if (count == 0 || count > IBMASM_EVENT_MAX_SIZE)
+		return 0;
+	if (*offset != 0)
+		return 0;
+
+	ret = ibmasm_get_next_event(event_data->sp, reader);
+	if (ret <= 0)
+		return ret;
+
+	if (count < reader->data_size)
+		return -EINVAL;
+
+        if (copy_to_user(buf, reader->data, reader->data_size))
+		return -EFAULT;
+
+	return reader->data_size;
+}
+
+static ssize_t event_file_write(struct file *file, const char *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;
+
+	wake_up_interruptible(&event_data->reader.wait);
+	return 0;
+}
+
+static int r_heartbeat_file_open(struct inode *inode, struct file *file)
+{
+	struct ibmasmfs_heartbeat_data *rhbeat;
+
+	if (!inode->u.generic_ip)
+		return -ENODEV;
+
+	rhbeat = kmalloc(sizeof(struct ibmasmfs_heartbeat_data), GFP_KERNEL);
+	if (!rhbeat)
+		return -ENOMEM;
+
+	rhbeat->sp = (struct service_processor *)inode->u.generic_ip;
+	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 *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 *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->u.generic_ip;
+	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 *buf, size_t count, loff_t *offset)
+{
+	unsigned long address = (unsigned long)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 *ubuff, size_t count, loff_t *offset)
+{
+	unsigned long address = (unsigned long)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((void *)buff, (void *)ubuff, count)) {
+		kfree(buff);
+		return -EFAULT;
+	}
+	
+	value = simple_strtoul(buff, NULL, 10);
+	writel(value, address);
+	kfree(buff);
+
+	return count;
+}
+
+static int remote_event_file_open(struct inode *inode, struct file *file)
+{
+	struct service_processor *sp;
+	unsigned long flags;
+	struct remote_queue *q;
+	
+	file->private_data = inode->u.generic_ip;
+	sp = file->private_data;
+	q = &sp->remote_queue;
+
+	/* allow only one event reader */
+	spin_lock_irqsave(&sp->lock, flags);
+	if (q->open) {
+		spin_unlock_irqrestore(&sp->lock, flags);
+		return -EBUSY;
+	}
+	q->open = 1;
+	spin_unlock_irqrestore(&sp->lock, flags);
+
+	enable_mouse_interrupts(sp);
+	
+	return 0;
+}
+
+static int remote_event_file_close(struct inode *inode, struct file *file)
+{
+	struct service_processor *sp = file->private_data;
+
+	disable_mouse_interrupts(sp);
+	wake_up_interruptible(&sp->remote_queue.wait);
+	sp->remote_queue.open = 0;
+
+	return 0;
+}
+
+static ssize_t remote_event_file_read(struct file *file, char *buf, size_t count, loff_t *offset)
+{
+	struct service_processor *sp = file->private_data;
+	struct remote_queue *q = &sp->remote_queue;
+	size_t data_size;
+	struct remote_event *reader = q->reader;
+	size_t num_events;
+
+	if (*offset < 0)
+		return -EINVAL;
+	if (count == 0 || count > 1024)
+		return 0;
+	if (*offset != 0)
+		return 0;
+
+	if (wait_event_interruptible(q->wait, q->reader != q->writer))
+		return -ERESTARTSYS;
+
+	/* only get multiples of struct remote_event */
+	num_events = min((count/sizeof(struct remote_event)), ibmasm_events_available(q));
+	if (!num_events)
+		return 0;
+
+	data_size = num_events * sizeof(struct remote_event);
+
+	if (copy_to_user(buf, reader, data_size))
+		return -EFAULT;
+
+	ibmasm_advance_reader(q, num_events);
+
+	return data_size;
+}
+
+
+static struct file_operations command_fops = {
+	.open =		command_file_open,
+	.release =	command_file_close,
+	.read =		command_file_read,
+	.write =	command_file_write,
+};
+
+static struct file_operations event_fops = {
+	.open =		event_file_open,
+	.release =	event_file_close,
+	.read =		event_file_read,
+	.write 		event_file_write,
+};
+
+static 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 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 struct file_operations remote_event_fops = {
+	.open =		remote_event_file_open,
+	.release =	remote_event_file_close,
+	.read =		remote_event_file_read,
+};
+
+
+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);
+		ibmasmfs_create_file(sb, remote_dir, "connected", &remote_settings_fops, (void *)vnc_status(sp), S_IRUSR);
+		ibmasmfs_create_file(sb, remote_dir, "events", &remote_event_fops, (void *)sp, S_IRUSR);
+	}
+}