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);
+	}
+}