Hi! I'm one of the developers on the CDEmu project.
We want to get a driver merged into vanilla linux kernel. CDEmu is a
software suite that allows people to take a CD/DVD-image and mount it on
the system in the form of a virtual disc. Major parts of this software
is based on user-space components, but we have a kernel module that's
responsible for acting like a SCSI HBA. Mainly all
this HBA does is to send requests to a userspace daemon for processing
and then fetch the result and send it back to the SCSI subsystem.
The project's homepage is here: http://cdemu.sourceforge.net
I went over the code to make sure it follows the coding style that's
used. Is there anything else I need to do? I'm a programmer but
kernel code is something that I seldom touch.
Any help is appreciated.
Sincerely,
Henrik Stokseth
/*
* vhba.c
*
* Copyright (C) 2007 Chia-I Wu <b90201047 AT ntu DOT edu DOT tw>
*
* 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.
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/highmem.h>
#include <linux/fs.h>
#include <linux/sched.h>
#include <linux/platform_device.h>
#include <linux/miscdevice.h>
#include <linux/poll.h>
#include <asm/uaccess.h>
#include <scsi/scsi.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_device.h>
#include <kernel.api.h>
MODULE_AUTHOR("Chia-I Wu");
MODULE_VERSION(VHBA_VERSION);
MODULE_DESCRIPTION("Virtual SCSI HBA");
MODULE_LICENSE("GPL");
#ifdef DEBUG
#define DPRINTK(fmt, args...) printk(KERN_DEBUG "%s: " fmt, __FUNCTION__, ## args)
#else
#define DPRINTK(fmt, args...)
#endif
#define scmd_dbg(scmd, fmt, a...) \
dev_dbg(&(scmd)->device->sdev_gendev, fmt, ##a)
#define scmd_warn(scmd, fmt, a...) \
dev_warn(&(scmd)->device->sdev_gendev, fmt, ##a)
#define VHBA_MAX_SECTORS_PER_IO 128
#define VHBA_MAX_ID 32
#define VHBA_CAN_QUEUE 32
#define VHBA_INVALID_ID VHBA_MAX_ID
#define DATA_TO_DEVICE(dir) ((dir) == DMA_TO_DEVICE || (dir) == DMA_BIDIRECTIONAL)
#define DATA_FROM_DEVICE(dir) ((dir) == DMA_FROM_DEVICE || (dir) == DMA_BIDIRECTIONAL)
enum vhba_req_state {
VHBA_REQ_FREE,
VHBA_REQ_PENDING,
VHBA_REQ_READING,
VHBA_REQ_SENT,
VHBA_REQ_WRITING,
};
struct vhba_command {
struct scsi_cmnd *cmd;
int status;
struct list_head entry;
};
struct vhba_device {
uint id;
spinlock_t cmd_lock;
struct list_head cmd_list;
wait_queue_head_t cmd_wq;
atomic_t refcnt;
};
struct vhba_host {
struct Scsi_Host *shost;
spinlock_t cmd_lock;
int cmd_next;
struct vhba_command commands[VHBA_CAN_QUEUE];
spinlock_t dev_lock;
struct vhba_device *devices[VHBA_MAX_ID];
int num_devices;
DECLARE_BITMAP(chgmap, VHBA_MAX_ID);
struct work_struct scan_devices;
};
#define MAX_COMMAND_SIZE 16
struct vhba_request {
__u32 tag;
__u32 lun;
__u8 cdb[MAX_COMMAND_SIZE];
__u8 cdb_len;
__u32 data_len;
};
struct vhba_response {
__u32 tag;
__u32 status;
__u32 data_len;
};
static struct vhba_command *vhba_alloc_command(void);
static void vhba_free_command(struct vhba_command *vcmd);
static struct platform_device vhba_platform_device;
static struct vhba_device *vhba_device_alloc(void)
{
struct vhba_device *vdev;
vdev = kzalloc(sizeof(struct vhba_device), GFP_KERNEL);
if (!vdev)
return NULL;
vdev->id = VHBA_INVALID_ID;
spin_lock_init(&vdev->cmd_lock);
INIT_LIST_HEAD(&vdev->cmd_list);
init_waitqueue_head(&vdev->cmd_wq);
atomic_set(&vdev->refcnt, 1);
return vdev;
}
static void vhba_device_put(struct vhba_device *vdev)
{
if (atomic_dec_and_test(&vdev->refcnt))
kfree(vdev);
}
static struct vhba_device *vhba_device_get(struct vhba_device *vdev)
{
atomic_inc(&vdev->refcnt);
return vdev;
}
static int vhba_device_queue(struct vhba_device *vdev, struct scsi_cmnd *cmd)
{
struct vhba_command *vcmd;
unsigned long flags;
vcmd = vhba_alloc_command();
if (!vcmd)
return SCSI_MLQUEUE_HOST_BUSY;
vcmd->cmd = cmd;
spin_lock_irqsave(&vdev->cmd_lock, flags);
list_add_tail(&vcmd->entry, &vdev->cmd_list);
spin_unlock_irqrestore(&vdev->cmd_lock, flags);
wake_up_interruptible(&vdev->cmd_wq);
return 0;
}
static int vhba_device_dequeue(struct vhba_device *vdev, struct scsi_cmnd *cmd)
{
struct vhba_command *vcmd;
int retval;
unsigned long flags;
spin_lock_irqsave(&vdev->cmd_lock, flags);
list_for_each_entry(vcmd, &vdev->cmd_list, entry) {
if (vcmd->cmd == cmd) {
list_del_init(&vcmd->entry);
break;
}
}
/* command not found */
if (&vcmd->entry == &vdev->cmd_list) {
spin_unlock_irqrestore(&vdev->cmd_lock, flags);
return SUCCESS;
}
while (vcmd->status == VHBA_REQ_READING || vcmd->status == VHBA_REQ_WRITING) {
spin_unlock_irqrestore(&vdev->cmd_lock, flags);
scmd_dbg(cmd, "wait for I/O before aborting\n");
schedule_timeout(1);
spin_lock_irqsave(&vdev->cmd_lock, flags);
}
retval = (vcmd->status == VHBA_REQ_SENT) ? FAILED : SUCCESS;
vhba_free_command(vcmd);
spin_unlock_irqrestore(&vdev->cmd_lock, flags);
return retval;
}
static void vhba_scan_devices(struct work_struct *work)
{
struct vhba_host *vhost = container_of(work, struct vhba_host, scan_devices);
int id;
unsigned long flags;
/* no need to lock here; it'll be scheduled and run again if some device missed */
while ((id = find_first_bit(vhost->chgmap, vhost->shost->max_id)) < vhost->shost->max_id) {
int remove;
spin_lock_irqsave(&vhost->dev_lock, flags);
clear_bit(id, vhost->chgmap);
remove = !(vhost->devices[id]);
spin_unlock_irqrestore(&vhost->dev_lock, flags);
dev_dbg(&vhost->shost->shost_gendev, "try to %s target 0:%d:0\n", (remove) ? "remove" : "add", id);
if (remove) {
struct scsi_device *sdev;
sdev = scsi_device_lookup(vhost->shost, 0, id, 0);
if (sdev) {
scsi_remove_device(sdev);
scsi_device_put(sdev);
}
} else {
scsi_add_device(vhost->shost, 0, id, 0);
}
}
}
static int vhba_add_device(struct vhba_device *vdev)
{
struct vhba_host *vhost;
int i;
unsigned long flags;
vhost = platform_get_drvdata(&vhba_platform_device);
vhba_device_get(vdev);
spin_lock_irqsave(&vhost->dev_lock, flags);
if (vhost->num_devices >= vhost->shost->max_id) {
spin_unlock_irqrestore(&vhost->dev_lock, flags);
vhba_device_put(vdev);
return -EBUSY;
}
for (i = 0; i < vhost->shost->max_id; i++) {
if (vhost->devices[i] == NULL) {
vdev->id = i;
vhost->devices[i] = vdev;
vhost->num_devices++;
set_bit(vdev->id, vhost->chgmap);
break;
}
}
spin_unlock_irqrestore(&vhost->dev_lock, flags);
schedule_work(&vhost->scan_devices);
return 0;
}
static int vhba_remove_device(struct vhba_device *vdev)
{
struct vhba_host *vhost;
unsigned long flags;
vhost = platform_get_drvdata(&vhba_platform_device);
spin_lock_irqsave(&vhost->dev_lock, flags);
set_bit(vdev->id, vhost->chgmap);
vhost->devices[vdev->id] = NULL;
vhost->num_devices--;
vdev->id = VHBA_INVALID_ID;
spin_unlock_irqrestore(&vhost->dev_lock, flags);
vhba_device_put(vdev);
schedule_work(&vhost->scan_devices);
return 0;
}
static struct vhba_device *vhba_lookup_device(int id)
{
struct vhba_host *vhost;
struct vhba_device *vdev = NULL;
unsigned long flags;
vhost = platform_get_drvdata(&vhba_platform_device);
if (likely(id < vhost->shost->max_id)) {
spin_lock_irqsave(&vhost->dev_lock, flags);
vdev = vhost->devices[id];
if (vdev)
vdev = vhba_device_get(vdev);
spin_unlock_irqrestore(&vhost->dev_lock, flags);
}
return vdev;
}
static struct vhba_command *vhba_alloc_command(void)
{
struct vhba_host *vhost;
struct vhba_command *vcmd;
unsigned long flags;
int i;
vhost = platform_get_drvdata(&vhba_platform_device);
spin_lock_irqsave(&vhost->cmd_lock, flags);
vcmd = vhost->commands + vhost->cmd_next++;
if (vcmd->status != VHBA_REQ_FREE) {
for (i = 0; i < vhost->shost->can_queue; i++) {
vcmd = vhost->commands + i;
if (vcmd->status == VHBA_REQ_FREE) {
vhost->cmd_next = i + 1;
break;
}
}
if (i == vhost->shost->can_queue)
vcmd = NULL;
}
if (vcmd)
vcmd->status = VHBA_REQ_PENDING;
vhost->cmd_next %= vhost->shost->can_queue;
spin_unlock_irqrestore(&vhost->cmd_lock, flags);
return vcmd;
}
static void vhba_free_command(struct vhba_command *vcmd)
{
struct vhba_host *vhost;
unsigned long flags;
vhost = platform_get_drvdata(&vhba_platform_device);
spin_lock_irqsave(&vhost->cmd_lock, flags);
vcmd->status = VHBA_REQ_FREE;
spin_unlock_irqrestore(&vhost->cmd_lock, flags);
}
static int vhba_queuecommand(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *))
{
struct vhba_device *vdev;
int retval;
scmd_dbg(cmd, "queue %lu\n", cmd->serial_number);
vdev = vhba_lookup_device(cmd->device->id);
if (!vdev) {
scmd_dbg(cmd, "no such device\n");
cmd->result = DID_NO_CONNECT << 16;
done(cmd);
return 0;
}
cmd->scsi_done = done;
retval = vhba_device_queue(vdev, cmd);
vhba_device_put(vdev);
return retval;
}
static int vhba_abort(struct scsi_cmnd *cmd)
{
struct vhba_device *vdev;
int retval = SUCCESS;
scmd_warn(cmd, "abort %lu\n", cmd->serial_number);
vdev = vhba_lookup_device(cmd->device->id);
if (vdev) {
retval = vhba_device_dequeue(vdev, cmd);
vhba_device_put(vdev);
} else {
cmd->result = DID_NO_CONNECT << 16;
}
return retval;
}
static struct scsi_host_template vhba_template = {
.module = THIS_MODULE,
.name = "vhba",
.proc_name = "vhba",
.queuecommand = vhba_queuecommand,
.eh_abort_handler = vhba_abort,
.can_queue = VHBA_CAN_QUEUE,
.this_id = -1,
.cmd_per_lun = 1,
.max_sectors = VHBA_MAX_SECTORS_PER_IO,
.sg_tablesize = 256,
};
static ssize_t do_request(struct scsi_cmnd *cmd, char __user *buf, size_t buf_len)
{
struct vhba_request vreq;
ssize_t ret;
scmd_dbg(cmd, "request %lu, cdb 0x%x, bufflen %d, use_sg %d\n",
cmd->serial_number, cmd->cmnd[0], scsi_bufflen(cmd), scsi_sg_count(cmd));
ret = sizeof(vreq);
if (DATA_TO_DEVICE(cmd->sc_data_direction))
ret += scsi_bufflen(cmd);
if (ret > buf_len) {
scmd_warn(cmd, "buffer too small (%zd < %zd) for a request\n", buf_len, ret);
return -EIO;
}
vreq.tag = cmd->serial_number;
vreq.lun = cmd->device->lun;
memcpy(vreq.cdb, cmd->cmnd, MAX_COMMAND_SIZE);
vreq.cdb_len = cmd->cmd_len;
vreq.data_len = scsi_bufflen(cmd);
if (copy_to_user(buf, &vreq, sizeof(vreq)))
return -EFAULT;
if (DATA_TO_DEVICE(cmd->sc_data_direction) && vreq.data_len) {
buf += sizeof(vreq);
/* XXX use_sg? */
if (copy_to_user(buf, scsi_sglist(cmd), vreq.data_len))
return -EFAULT;
}
return ret;
}
static ssize_t do_response(struct scsi_cmnd *cmd, const char __user *buf, size_t buf_len, struct vhba_response *res)
{
ssize_t ret = 0;
scmd_dbg(cmd, "response %lu, status %x, data len %d, use_sg %d\n",
cmd->serial_number, res->status, res->data_len, scsi_sg_count(cmd));
if (res->status) {
if (res->data_len > SCSI_SENSE_BUFFERSIZE) {
scmd_warn(cmd, "truncate sense (%d < %d)", SCSI_SENSE_BUFFERSIZE, res->data_len);
res->data_len = SCSI_SENSE_BUFFERSIZE;
}
if (copy_from_user(cmd->sense_buffer, buf, res->data_len))
return -EFAULT;
cmd->result = res->status;
ret += res->data_len;
} else if (DATA_FROM_DEVICE(cmd->sc_data_direction) && scsi_bufflen(cmd)) {
size_t to_read;
if (res->data_len > scsi_bufflen(cmd)) {
scmd_warn(cmd, "truncate data (%d < %d)\n", scsi_bufflen(cmd), res->data_len);
res->data_len = scsi_bufflen(cmd);
}
to_read = res->data_len;
if (scsi_sg_count(cmd)) {
unsigned char buf_stack[64];
unsigned char *kaddr, *uaddr, *kbuf;
struct scatterlist *sg = scsi_sglist(cmd);
int i;
uaddr = (unsigned char *) buf;
if (res->data_len > 64) {
kbuf = kmalloc(PAGE_SIZE, GFP_KERNEL);
} else {
kbuf = buf_stack;
}
for (i = 0; i < scsi_sg_count(cmd); i++) {
size_t len = (sg[i].length < to_read) ? sg[i].length : to_read;
if (copy_from_user(kbuf, uaddr, len)) {
if (kbuf != buf_stack)
kfree(kbuf);
return -EFAULT;
}
uaddr += len;
kaddr = kmap_atomic(sg_page(&sg[i]), KM_USER0);
memcpy(kaddr + sg[i].offset, kbuf, len);
kunmap_atomic(kaddr, KM_USER0);
to_read -= len;
if (to_read == 0)
break;
}
if (kbuf != buf_stack)
kfree(kbuf);
} else {
if (copy_from_user(scsi_sglist(cmd), buf, res->data_len))
return -EFAULT;
to_read -= res->data_len;
}
scsi_set_resid(cmd, to_read);
ret += res->data_len - to_read;
}
return ret;
}
static inline struct vhba_command *next_command(struct vhba_device *vdev)
{
struct vhba_command *vcmd;
list_for_each_entry(vcmd, &vdev->cmd_list, entry) {
if (vcmd->status == VHBA_REQ_PENDING)
break;
}
if (&vcmd->entry == &vdev->cmd_list)
vcmd = NULL;
return vcmd;
}
static inline struct vhba_command *match_command(struct vhba_device *vdev, u32 tag)
{
struct vhba_command *vcmd;
list_for_each_entry(vcmd, &vdev->cmd_list, entry) {
if (vcmd->cmd->serial_number == tag)
break;
}
if (&vcmd->entry == &vdev->cmd_list)
vcmd = NULL;
return vcmd;
}
static struct vhba_command *wait_command(struct vhba_device *vdev, unsigned long flags)
{
struct vhba_command *vcmd;
DEFINE_WAIT(wait);
while (!(vcmd = next_command(vdev))) {
if (signal_pending(current))
break;
prepare_to_wait(&vdev->cmd_wq, &wait, TASK_INTERRUPTIBLE);
spin_unlock_irqrestore(&vdev->cmd_lock, flags);
schedule();
spin_lock_irqsave(&vdev->cmd_lock, flags);
}
finish_wait(&vdev->cmd_wq, &wait);
if (vcmd)
vcmd->status = VHBA_REQ_READING;
return vcmd;
}
static ssize_t vhba_ctl_read(struct file *file, char __user *buf, size_t buf_len, loff_t *offset)
{
struct vhba_device *vdev;
struct vhba_command *vcmd;
ssize_t ret;
unsigned long flags;
vdev = file->private_data;
spin_lock_irqsave(&vdev->cmd_lock, flags);
vcmd = wait_command(vdev, flags);
spin_unlock_irqrestore(&vdev->cmd_lock, flags);
if (!vcmd)
return -ERESTARTSYS;
ret = do_request(vcmd->cmd, buf, buf_len);
spin_lock_irqsave(&vdev->cmd_lock, flags);
if (ret >= 0) {
vcmd->status = VHBA_REQ_SENT;
*offset += ret;
} else {
vcmd->status = VHBA_REQ_PENDING;
}
spin_unlock_irqrestore(&vdev->cmd_lock, flags);
return ret;
}
static ssize_t vhba_ctl_write(struct file *file, const char __user *buf, size_t buf_len, loff_t *offset)
{
struct vhba_device *vdev;
struct vhba_command *vcmd;
struct vhba_response res;
ssize_t ret;
unsigned long flags;
if (buf_len < sizeof(res))
return -EIO;
if (copy_from_user(&res, buf, sizeof(res)))
return -EFAULT;
vdev = file->private_data;
spin_lock_irqsave(&vdev->cmd_lock, flags);
vcmd = match_command(vdev, res.tag);
if (!vcmd || vcmd->status != VHBA_REQ_SENT) {
spin_unlock_irqrestore(&vdev->cmd_lock, flags);
DPRINTK("not expecting response\n");
return -EIO;
}
vcmd->status = VHBA_REQ_WRITING;
spin_unlock_irqrestore(&vdev->cmd_lock, flags);
ret = do_response(vcmd->cmd, buf + sizeof(res), buf_len - sizeof(res), &res);
spin_lock_irqsave(&vdev->cmd_lock, flags);
if (ret >= 0) {
vcmd->cmd->scsi_done(vcmd->cmd);
ret += sizeof(res);
/* don't compete with vhba_device_dequeue */
if (!list_empty(&vcmd->entry)) {
list_del_init(&vcmd->entry);
vhba_free_command(vcmd);
}
} else {
vcmd->status = VHBA_REQ_SENT;
}
spin_unlock_irqrestore(&vdev->cmd_lock, flags);
return ret;
}
static int vhba_ctl_ioctl (struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
{
struct vhba_device *vdev = file->private_data;
struct vhba_host *vhost;
struct scsi_device *sdev;
switch (cmd) {
case 0xBEEF001:
vhost = platform_get_drvdata(&vhba_platform_device);
sdev = scsi_device_lookup(vhost->shost, 0, vdev->id, 0);
if (sdev) {
int id[4] = {
sdev->host->host_no,
sdev->channel,
sdev->id,
sdev->lun
};
scsi_device_put(sdev);
if (copy_to_user((void *)arg, id, sizeof(id)))
return -EFAULT;
return 0;
} else {
return -ENODEV;
}
}
return -ENOTTY;
}
static unsigned int vhba_ctl_poll(struct file *file, poll_table *wait)
{
struct vhba_device *vdev = file->private_data;
unsigned int mask = 0;
unsigned long flags;
poll_wait(file, &vdev->cmd_wq, wait);
spin_lock_irqsave(&vdev->cmd_lock, flags);
if (next_command(vdev))
mask |= POLLIN | POLLRDNORM;
spin_unlock_irqrestore(&vdev->cmd_lock, flags);
return mask;
}
static int vhba_ctl_open(struct inode *inode, struct file *file)
{
struct vhba_device *vdev;
int retval;
DPRINTK("open\n");
/* check if vhba is probed */
if (!platform_get_drvdata(&vhba_platform_device))
return -ENODEV;
vdev = vhba_device_alloc();
if (!vdev)
return -ENOMEM;
if (!(retval = vhba_add_device(vdev)))
file->private_data = vdev;
vhba_device_put(vdev);
return retval;
}
static int vhba_ctl_release(struct inode *inode, struct file *file)
{
struct vhba_device *vdev;
struct vhba_command *vcmd;
unsigned long flags;
DPRINTK("release\n");
vdev = file->private_data;
vhba_device_get(vdev);
vhba_remove_device(vdev);
spin_lock_irqsave(&vdev->cmd_lock, flags);
list_for_each_entry(vcmd, &vdev->cmd_list, entry) {
WARN_ON(vcmd->status == VHBA_REQ_READING || vcmd->status == VHBA_REQ_WRITING);
scmd_warn(vcmd->cmd, "device released with command %lu\n", vcmd->cmd->serial_number);
vcmd->cmd->result = DID_NO_CONNECT << 16;
vcmd->cmd->scsi_done(vcmd->cmd);
vhba_free_command(vcmd);
}
INIT_LIST_HEAD(&vdev->cmd_list);
spin_unlock_irqrestore(&vdev->cmd_lock, flags);
vhba_device_put(vdev);
return 0;
}
static struct file_operations vhba_ctl_fops = {
.owner = THIS_MODULE,
.open = vhba_ctl_open,
.release = vhba_ctl_release,
.read = vhba_ctl_read,
.write = vhba_ctl_write,
.poll = vhba_ctl_poll,
.ioctl = vhba_ctl_ioctl,
};
static struct miscdevice vhba_miscdev = {
.minor = MISC_DYNAMIC_MINOR,
.name = "vhba_ctl",
.fops = &vhba_ctl_fops,
};
static int vhba_probe(struct platform_device *pdev)
{
struct Scsi_Host *shost;
struct vhba_host *vhost;
int i;
shost = scsi_host_alloc(&vhba_template, sizeof(struct vhba_host));
if (!shost)
return -ENOMEM;
shost->max_id = VHBA_MAX_ID;
/* we don't support lun > 0 */
shost->max_lun = 1;
vhost = (struct vhba_host *) shost->hostdata;
memset(vhost, 0, sizeof(*vhost));
vhost->shost = shost;
vhost->num_devices = 0;
spin_lock_init(&vhost->dev_lock);
spin_lock_init(&vhost->cmd_lock);
INIT_WORK(&vhost->scan_devices, vhba_scan_devices);
vhost->cmd_next = 0;
for (i = 0; i < vhost->shost->can_queue; i++)
vhost->commands[i].status = VHBA_REQ_FREE;
platform_set_drvdata(pdev, vhost);
if (scsi_add_host(shost, &pdev->dev)) {
scsi_host_put(shost);
return -ENOMEM;
}
return 0;
}
static int vhba_remove(struct platform_device *pdev)
{
struct vhba_host *vhost;
struct Scsi_Host *shost;
vhost = platform_get_drvdata(pdev);
shost = vhost->shost;
scsi_remove_host(shost);
scsi_host_put(shost);
return 0;
}
static void vhba_release(struct device * dev)
{
return;
}
static struct platform_device vhba_platform_device = {
.name = "vhba",
.id = -1,
.dev = {
.release = vhba_release,
},
};
static struct platform_driver vhba_platform_driver = {
.driver = {
.owner = THIS_MODULE,
.name = "vhba",
},
.probe = vhba_probe,
.remove = vhba_remove,
};
static int __init vhba_init(void)
{
int ret;
ret = platform_device_register(&vhba_platform_device);
if (ret < 0)
return ret;
ret = platform_driver_register(&vhba_platform_driver);
if (ret < 0) {
platform_device_unregister(&vhba_platform_device);
return ret;
}
ret = misc_register(&vhba_miscdev);
if (ret < 0) {
platform_driver_unregister(&vhba_platform_driver);
platform_device_unregister(&vhba_platform_device);
return ret;
}
return 0;
}
static void __exit vhba_exit(void)
{
misc_deregister(&vhba_miscdev);
platform_driver_unregister(&vhba_platform_driver);
platform_device_unregister(&vhba_platform_device);
}
module_init(vhba_init);
module_exit(vhba_exit);
