pci_hotplug_core.c

linux和2410结合开发 用他可以生成2410所需的zImage文件

/*
 * PCI HotPlug Controller Core
 *
 * Copyright (c) 2001 Greg Kroah-Hartman ([e-mail])
 * Copyright (c) 2001 IBM Corp.
 *
 * All rights reserved.
 *
 * 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, GOOD TITLE or
 * NON INFRINGEMENT.  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., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 * Send feedback to <[e-mail]>
 *
 */

#include <linux/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/list.h>
#include <linux/pagemap.h>
#include <linux/slab.h>
#include <linux/smp_lock.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <asm/uaccess.h>
#include "pci_hotplug.h"


#if !defined(CONFIG_HOTPLUG_PCI_MODULE)
	#define MY_NAME	"pci_hotplug"
#else
	#define MY_NAME	THIS_MODULE->name
#endif

#define dbg(fmt, arg...) do { if (debug) printk(KERN_DEBUG "%s: "__FUNCTION__": " fmt , MY_NAME , ## arg); } while (0)
#define err(format, arg...) printk(KERN_ERR "%s: " format , MY_NAME , ## arg)
#define info(format, arg...) printk(KERN_INFO "%s: " format , MY_NAME , ## arg)
#define warn(format, arg...) printk(KERN_WARNING "%s: " format , MY_NAME , ## arg)


/* local variables */
static int debug;

#define DRIVER_VERSION	"0.3"
#define DRIVER_AUTHOR	"Greg Kroah-Hartman <[e-mail]>"
#define DRIVER_DESC	"PCI Hot Plug PCI Core"


//////////////////////////////////////////////////////////////////

/* Random magic number */
#define PCIHPFS_MAGIC 0x52454541

struct hotplug_slot_core {
	struct dentry	*dir_dentry;
	struct dentry	*power_dentry;
	struct dentry	*attention_dentry;
	struct dentry	*latch_dentry;
	struct dentry	*adapter_dentry;
	struct dentry	*test_dentry;
};

static struct super_operations pcihpfs_ops;
static struct address_space_operations pcihpfs_aops;
static struct file_operations pcihpfs_dir_operations;
static struct file_operations default_file_operations;
static struct inode_operations pcihpfs_dir_inode_operations;
static struct vfsmount *pcihpfs_mount;	/* one of the mounts of our fs for reference counting */
static int pcihpfs_mount_count;		/* times we have mounted our fs */
static spinlock_t mount_lock;		/* protects our mount_count */
static spinlock_t list_lock;

LIST_HEAD(pci_hotplug_slot_list);


static int pcihpfs_statfs (struct super_block *sb, struct statfs *buf)
{
	buf->f_type = PCIHPFS_MAGIC;
	buf->f_bsize = PAGE_CACHE_SIZE;
	buf->f_namelen = 255;
	return 0;
}

static struct dentry *pcihpfs_lookup (struct inode *dir, struct dentry *dentry)
{
	d_add(dentry, NULL);
	return NULL;
}

static struct inode *pcihpfs_get_inode (struct super_block *sb, int mode, int dev)
{
	struct inode *inode = new_inode(sb);

	if (inode) {
		inode->i_mode = mode;
		inode->i_uid = current->fsuid;
		inode->i_gid = current->fsgid;
		inode->i_blksize = PAGE_CACHE_SIZE;
		inode->i_blocks = 0;
		inode->i_rdev = NODEV;
		inode->i_mapping->a_ops = &pcihpfs_aops;
		inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
		switch (mode & S_IFMT) {
		default:
			init_special_inode(inode, mode, dev);
			break;
		case S_IFREG:
			inode->i_fop = &default_file_operations;
			break;
		case S_IFDIR:
			inode->i_op = &pcihpfs_dir_inode_operations;
			inode->i_fop = &pcihpfs_dir_operations;
			break;
		}
	}
	return inode; 
}

static int pcihpfs_mknod (struct inode *dir, struct dentry *dentry, int mode, int dev)
{
	struct inode *inode = pcihpfs_get_inode(dir->i_sb, mode, dev);
	int error = -ENOSPC;

	if (inode) {
		d_instantiate(dentry, inode);
		dget(dentry);
		error = 0;
	}
	return error;
}

static int pcihpfs_mkdir (struct inode *dir, struct dentry *dentry, int mode)
{
	return pcihpfs_mknod (dir, dentry, mode | S_IFDIR, 0);
}

static int pcihpfs_create (struct inode *dir, struct dentry *dentry, int mode)
{
 	return pcihpfs_mknod (dir, dentry, mode | S_IFREG, 0);
}

static int pcihpfs_link (struct dentry *old_dentry, struct inode *dir,
			 struct dentry *dentry)
{
	struct inode *inode = old_dentry->d_inode;

	if(S_ISDIR(inode->i_mode))
		return -EPERM;

	inode->i_nlink++;
	atomic_inc(&inode->i_count);
 	dget(dentry);
	d_instantiate(dentry, inode);
	return 0;
}

static inline int pcihpfs_positive (struct dentry *dentry)
{
	return dentry->d_inode && !d_unhashed(dentry);
}

static int pcihpfs_empty (struct dentry *dentry)
{
	struct list_head *list;

	spin_lock(&dcache_lock);

	list_for_each(list, &dentry->d_subdirs) {
		struct dentry *de = list_entry(list, struct dentry, d_child);
		if (pcihpfs_positive(de)) {
			spin_unlock(&dcache_lock);
			return 0;
		}
	}

	spin_unlock(&dcache_lock);
	return 1;
}

static int pcihpfs_unlink (struct inode *dir, struct dentry *dentry)
{
	int error = -ENOTEMPTY;

	if (pcihpfs_empty(dentry)) {
		struct inode *inode = dentry->d_inode;

		inode->i_nlink--;
		dput(dentry);
		error = 0;
	}
	return error;
}

static int pcihpfs_rename (struct inode *old_dir, struct dentry *old_dentry,
			   struct inode *new_dir, struct dentry *new_dentry)
{
	int error = -ENOTEMPTY;

	if (pcihpfs_empty(new_dentry)) {
		struct inode *inode = new_dentry->d_inode;
		if (inode) {
			inode->i_nlink--;
			dput(new_dentry);
		}
		error = 0;
	}
	return error;
}

#define pcihpfs_rmdir pcihpfs_unlink

/* default file operations */
static ssize_t default_read_file (struct file *file, char *buf, size_t count, loff_t *ppos)
{
	dbg ("\n");
	return 0;
}

static ssize_t default_write_file (struct file *file, const char *buf, size_t count, loff_t *ppos)
{
	dbg ("\n");
	return count;
}

static loff_t default_file_lseek (struct file *file, loff_t offset, int orig)
{
	loff_t retval = -EINVAL;

	switch(orig) {
	case 0:
		if (offset > 0) {
			file->f_pos = offset;
			retval = file->f_pos;
		} 
		break;
	case 1:
		if ((offset + file->f_pos) > 0) {
			file->f_pos += offset;
			retval = file->f_pos;
		} 
		break;
	default:
		break;
	}
	return retval;
}

static int default_open (struct inode *inode, struct file *filp)
{
	if (inode->u.generic_ip)
		filp->private_data = inode->u.generic_ip;

	return 0;
}

static int default_sync_file (struct file *file, struct dentry *dentry, int datasync)
{
	return 0;
}

static struct address_space_operations pcihpfs_aops = {
};

static struct file_operations pcihpfs_dir_operations = {
	read:		generic_read_dir,
	readdir:	dcache_readdir,
	fsync:		default_sync_file,
};

static struct file_operations default_file_operations = {
	read:		default_read_file,
	write:		default_write_file,
	open:		default_open,
	llseek:		default_file_lseek,
	fsync:		default_sync_file,
	mmap:		generic_file_mmap,
};

/* file ops for the "power" files */
static ssize_t power_read_file (struct file *file, char *buf, size_t count, loff_t *offset);
static ssize_t power_write_file (struct file *file, const char *buf, size_t count, loff_t *ppos);
static struct file_operations power_file_operations = {
	read:		power_read_file,
	write:		power_write_file,
	open:		default_open,
	llseek:		default_file_lseek,
	fsync:		default_sync_file,
	mmap:		generic_file_mmap,
};

/* file ops for the "attention" files */
static ssize_t attention_read_file (struct file *file, char *buf, size_t count, loff_t *offset);
static ssize_t attention_write_file (struct file *file, const char *buf, size_t count, loff_t *ppos);
static struct file_operations attention_file_operations = {
	read:		attention_read_file,
	write:		attention_write_file,
	open:		default_open,
	llseek:		default_file_lseek,
	fsync:		default_sync_file,
	mmap:		generic_file_mmap,
};

/* file ops for the "latch" files */
static ssize_t latch_read_file (struct file *file, char *buf, size_t count, loff_t *offset);
static struct file_operations latch_file_operations = {
	read:		latch_read_file,
	write:		default_write_file,
	open:		default_open,
	llseek:		default_file_lseek,
	fsync:		default_sync_file,
	mmap:		generic_file_mmap,
};

/* file ops for the "presence" files */
static ssize_t presence_read_file (struct file *file, char *buf, size_t count, loff_t *offset);
static struct file_operations presence_file_operations = {
	read:		presence_read_file,
	write:		default_write_file,
	open:		default_open,
	llseek:		default_file_lseek,
	fsync:		default_sync_file,
	mmap:		generic_file_mmap,
};

/* file ops for the "test" files */
static ssize_t test_write_file (struct file *file, const char *buf, size_t count, loff_t *ppos);
static struct file_operations test_file_operations = {
	read:		default_read_file,
	write:		test_write_file,
	open:		default_open,
	llseek:		default_file_lseek,
	fsync:		default_sync_file,
	mmap:		generic_file_mmap,
};

static struct inode_operations pcihpfs_dir_inode_operations = {
	create:		pcihpfs_create,
	lookup:		pcihpfs_lookup,
	link:		pcihpfs_link,
	unlink:		pcihpfs_unlink,
	mkdir:		pcihpfs_mkdir,
	rmdir:		pcihpfs_rmdir,
	mknod:		pcihpfs_mknod,
	rename:		pcihpfs_rename,
};

static struct super_operations pcihpfs_ops = {
	statfs:		pcihpfs_statfs,
	put_inode:	force_delete,
};

static struct super_block *pcihpfs_read_super (struct super_block *sb, void *data, int silent)
{
	struct inode *inode;
	struct dentry *root;

	sb->s_blocksize = PAGE_CACHE_SIZE;
	sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
	sb->s_magic = PCIHPFS_MAGIC;
	sb->s_op = &pcihpfs_ops;
	inode = pcihpfs_get_inode(sb, S_IFDIR | 0755, 0);

	if (!inode) {
		dbg("%s: could not get inode!\n",__FUNCTION__);
		return NULL;
	}

	root = d_alloc_root(inode);
	if (!root) {
		dbg("%s: could not get root dentry!\n",__FUNCTION__);
		iput(inode);
		return NULL;
	}
	sb->s_root = root;
	return sb;
}

static DECLARE_FSTYPE(pcihpfs_fs_type, "pcihpfs", pcihpfs_read_super, FS_SINGLE | FS_LITTER);

static int get_mount (void)
{
	struct vfsmount *mnt;

	spin_lock (&mount_lock);
	if (pcihpfs_mount) {
		mntget(pcihpfs_mount);
		++pcihpfs_mount_count;
		spin_unlock (&mount_lock);
		goto go_ahead;
	}

	spin_unlock (&mount_lock);
	mnt = kern_mount (&pcihpfs_fs_type);
	if (IS_ERR(mnt)) {
		err ("could not mount the fs...erroring out!\n");
		return -ENODEV;
	}
	spin_lock (&mount_lock);
	if (!pcihpfs_mount) {
		pcihpfs_mount = mnt;
		++pcihpfs_mount_count;
		spin_unlock (&mount_lock);
		goto go_ahead;
	}
	mntget(pcihpfs_mount);
	++pcihpfs_mount_count;
	spin_unlock (&mount_lock);
	mntput(mnt);

go_ahead:
	dbg("pcihpfs_mount_count = %d\n", pcihpfs_mount_count);
	return 0;
}

static void remove_mount (void)
{
	struct vfsmount *mnt;

	spin_lock (&mount_lock);
	mnt = pcihpfs_mount;
	--pcihpfs_mount_count;
	if (!pcihpfs_mount_count)
		pcihpfs_mount = NULL;

	spin_unlock (&mount_lock);
	mntput(mnt);
	dbg("pcihpfs_mount_count = %d\n", pcihpfs_mount_count);
}


/**
 * pcihpfs_create_by_name - create a file, given a name
 * @name:	name of file
 * @mode:	type of file
 * @parent:	dentry of directory to create it in
 * @dentry:	resulting dentry of file
 *
 * There is a bit of overhead in creating a file - basically, we 
 * have to hash the name of the file, then look it up. This will
 * prevent files of the same name. 
 * We then call the proper vfs_ function to take care of all the 
 * file creation details. 
 * This function handles both regular files and directories.
 */
static int pcihpfs_create_by_name (const char *name, mode_t mode,
				   struct dentry *parent, struct dentry **dentry)
{
	struct dentry *d = NULL;
	struct qstr qstr;
	int error;

	/* If the parent is not specified, we create it in the root.
	 * We need the root dentry to do this, which is in the super 
	 * block. A pointer to that is in the struct vfsmount that we
	 * have around.
	 */
	if (!parent ) {
		if (pcihpfs_mount && pcihpfs_mount->mnt_sb) {
			parent = pcihpfs_mount->mnt_sb->s_root;
		}
	}

	if (!parent) {
		dbg("Ah! can not find a parent!\n");
		return -EFAULT;
	}

	*dentry = NULL;
	qstr.name = name;
	qstr.len = strlen(name);
 	qstr.hash = full_name_hash(name,qstr.len);

	parent = dget(parent);

	down(&parent->d_inode->i_sem);

	d = lookup_hash(&qstr,parent);

	error = PTR_ERR(d);
	if (!IS_ERR(d)) {
		switch(mode & S_IFMT) {
		case 0: 
		case S_IFREG:
			error = vfs_create(parent->d_inode,d,mode);
			break;
		case S_IFDIR:
			error = vfs_mkdir(parent->d_inode,d,mode);
			break;
		default:
			err("cannot create special files\n");
		}
		*dentry = d;
	}
	up(&parent->d_inode->i_sem);

	dput(parent);
	return error;
}

static struct dentry *fs_create_file (const char *name, mode_t mode,
				      struct dentry *parent, void *data,
				      struct file_operations *fops)
{
	struct dentry *dentry;
	int error;

	dbg("creating file '%s'\n",name);

	error = pcihpfs_create_by_name(name,mode,parent,&dentry);
	if (error) {
		dentry = NULL;
	} else {
		if (dentry->d_inode) {
			if (data)
				dentry->d_inode->u.generic_ip = data;
			if (fops)
			dentry->d_inode->i_fop = fops;
		}
	}

	return dentry;
}

static void fs_remove_file (struct dentry *dentry)
{
	struct dentry *parent = dentry->d_parent;
	
	if (!parent || !parent->d_inode)
		return;

	down(&parent->d_inode->i_sem);
	if (pcihpfs_positive(dentry)) {
		if (dentry->d_inode) {
			if (S_ISDIR(dentry->d_inode->i_mode))
				vfs_rmdir(parent->d_inode,dentry);
			else
				vfs_unlink(parent->d_inode,dentry);
		}

		dput(dentry);
	}
	up(&parent->d_inode->i_sem);
}

#define GET_STATUS(name)	\
static int get_##name##_status (struct hotplug_slot *slot, u8 *value)	\
{									\
	struct hotplug_slot_ops *ops = slot->ops;			\
	int retval = 0;							\
	if (ops->owner)							\
		__MOD_INC_USE_COUNT(ops->owner);			\
	if (ops->get_##name##_status)					\
		retval = ops->get_##name##_status (slot, value);	\
	else								\
		*value = slot->info->name##_status;			\