linux/drivers/block/aoe/aoechr.c
Paul Gortmaker d5decd3b95 block: add export.h to files using EXPORT_SYMBOL/THIS_MODULE macros
These files were getting <linux/module.h> via an implicit include
path, but we want to crush those out of existence since they cost
time during compiles of processing thousands of lines of headers
for no reason.  Give them the lightweight header that just contains
the EXPORT_SYMBOL infrastructure.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-31 19:31:12 -04:00

316 lines
6.1 KiB
C

/* Copyright (c) 2007 Coraid, Inc. See COPYING for GPL terms. */
/*
* aoechr.c
* AoE character device driver
*/
#include <linux/hdreg.h>
#include <linux/blkdev.h>
#include <linux/completion.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/mutex.h>
#include <linux/skbuff.h>
#include <linux/export.h>
#include "aoe.h"
enum {
//MINOR_STAT = 1, (moved to sysfs)
MINOR_ERR = 2,
MINOR_DISCOVER,
MINOR_INTERFACES,
MINOR_REVALIDATE,
MINOR_FLUSH,
MSGSZ = 2048,
NMSG = 100, /* message backlog to retain */
};
struct aoe_chardev {
ulong minor;
char name[32];
};
enum { EMFL_VALID = 1 };
struct ErrMsg {
short flags;
short len;
char *msg;
};
static DEFINE_MUTEX(aoechr_mutex);
static struct ErrMsg emsgs[NMSG];
static int emsgs_head_idx, emsgs_tail_idx;
static struct completion emsgs_comp;
static spinlock_t emsgs_lock;
static int nblocked_emsgs_readers;
static struct class *aoe_class;
static struct aoe_chardev chardevs[] = {
{ MINOR_ERR, "err" },
{ MINOR_DISCOVER, "discover" },
{ MINOR_INTERFACES, "interfaces" },
{ MINOR_REVALIDATE, "revalidate" },
{ MINOR_FLUSH, "flush" },
};
static int
discover(void)
{
aoecmd_cfg(0xffff, 0xff);
return 0;
}
static int
interfaces(const char __user *str, size_t size)
{
if (set_aoe_iflist(str, size)) {
printk(KERN_ERR
"aoe: could not set interface list: too many interfaces\n");
return -EINVAL;
}
return 0;
}
static int
revalidate(const char __user *str, size_t size)
{
int major, minor, n;
ulong flags;
struct aoedev *d;
struct sk_buff *skb;
char buf[16];
if (size >= sizeof buf)
return -EINVAL;
buf[sizeof buf - 1] = '\0';
if (copy_from_user(buf, str, size))
return -EFAULT;
/* should be e%d.%d format */
n = sscanf(buf, "e%d.%d", &major, &minor);
if (n != 2) {
printk(KERN_ERR "aoe: invalid device specification\n");
return -EINVAL;
}
d = aoedev_by_aoeaddr(major, minor);
if (!d)
return -EINVAL;
spin_lock_irqsave(&d->lock, flags);
aoecmd_cleanslate(d);
loop:
skb = aoecmd_ata_id(d);
spin_unlock_irqrestore(&d->lock, flags);
/* try again if we are able to sleep a bit,
* otherwise give up this revalidation
*/
if (!skb && !msleep_interruptible(200)) {
spin_lock_irqsave(&d->lock, flags);
goto loop;
}
if (skb) {
struct sk_buff_head queue;
__skb_queue_head_init(&queue);
__skb_queue_tail(&queue, skb);
aoenet_xmit(&queue);
}
aoecmd_cfg(major, minor);
return 0;
}
void
aoechr_error(char *msg)
{
struct ErrMsg *em;
char *mp;
ulong flags, n;
n = strlen(msg);
spin_lock_irqsave(&emsgs_lock, flags);
em = emsgs + emsgs_tail_idx;
if ((em->flags & EMFL_VALID)) {
bail: spin_unlock_irqrestore(&emsgs_lock, flags);
return;
}
mp = kmalloc(n, GFP_ATOMIC);
if (mp == NULL) {
printk(KERN_ERR "aoe: allocation failure, len=%ld\n", n);
goto bail;
}
memcpy(mp, msg, n);
em->msg = mp;
em->flags |= EMFL_VALID;
em->len = n;
emsgs_tail_idx++;
emsgs_tail_idx %= ARRAY_SIZE(emsgs);
spin_unlock_irqrestore(&emsgs_lock, flags);
if (nblocked_emsgs_readers)
complete(&emsgs_comp);
}
static ssize_t
aoechr_write(struct file *filp, const char __user *buf, size_t cnt, loff_t *offp)
{
int ret = -EINVAL;
switch ((unsigned long) filp->private_data) {
default:
printk(KERN_INFO "aoe: can't write to that file.\n");
break;
case MINOR_DISCOVER:
ret = discover();
break;
case MINOR_INTERFACES:
ret = interfaces(buf, cnt);
break;
case MINOR_REVALIDATE:
ret = revalidate(buf, cnt);
break;
case MINOR_FLUSH:
ret = aoedev_flush(buf, cnt);
}
if (ret == 0)
ret = cnt;
return ret;
}
static int
aoechr_open(struct inode *inode, struct file *filp)
{
int n, i;
mutex_lock(&aoechr_mutex);
n = iminor(inode);
filp->private_data = (void *) (unsigned long) n;
for (i = 0; i < ARRAY_SIZE(chardevs); ++i)
if (chardevs[i].minor == n) {
mutex_unlock(&aoechr_mutex);
return 0;
}
mutex_unlock(&aoechr_mutex);
return -EINVAL;
}
static int
aoechr_rel(struct inode *inode, struct file *filp)
{
return 0;
}
static ssize_t
aoechr_read(struct file *filp, char __user *buf, size_t cnt, loff_t *off)
{
unsigned long n;
char *mp;
struct ErrMsg *em;
ssize_t len;
ulong flags;
n = (unsigned long) filp->private_data;
if (n != MINOR_ERR)
return -EFAULT;
spin_lock_irqsave(&emsgs_lock, flags);
for (;;) {
em = emsgs + emsgs_head_idx;
if ((em->flags & EMFL_VALID) != 0)
break;
if (filp->f_flags & O_NDELAY) {
spin_unlock_irqrestore(&emsgs_lock, flags);
return -EAGAIN;
}
nblocked_emsgs_readers++;
spin_unlock_irqrestore(&emsgs_lock, flags);
n = wait_for_completion_interruptible(&emsgs_comp);
spin_lock_irqsave(&emsgs_lock, flags);
nblocked_emsgs_readers--;
if (n) {
spin_unlock_irqrestore(&emsgs_lock, flags);
return -ERESTARTSYS;
}
}
if (em->len > cnt) {
spin_unlock_irqrestore(&emsgs_lock, flags);
return -EAGAIN;
}
mp = em->msg;
len = em->len;
em->msg = NULL;
em->flags &= ~EMFL_VALID;
emsgs_head_idx++;
emsgs_head_idx %= ARRAY_SIZE(emsgs);
spin_unlock_irqrestore(&emsgs_lock, flags);
n = copy_to_user(buf, mp, len);
kfree(mp);
return n == 0 ? len : -EFAULT;
}
static const struct file_operations aoe_fops = {
.write = aoechr_write,
.read = aoechr_read,
.open = aoechr_open,
.release = aoechr_rel,
.owner = THIS_MODULE,
.llseek = noop_llseek,
};
static char *aoe_devnode(struct device *dev, mode_t *mode)
{
return kasprintf(GFP_KERNEL, "etherd/%s", dev_name(dev));
}
int __init
aoechr_init(void)
{
int n, i;
n = register_chrdev(AOE_MAJOR, "aoechr", &aoe_fops);
if (n < 0) {
printk(KERN_ERR "aoe: can't register char device\n");
return n;
}
init_completion(&emsgs_comp);
spin_lock_init(&emsgs_lock);
aoe_class = class_create(THIS_MODULE, "aoe");
if (IS_ERR(aoe_class)) {
unregister_chrdev(AOE_MAJOR, "aoechr");
return PTR_ERR(aoe_class);
}
aoe_class->devnode = aoe_devnode;
for (i = 0; i < ARRAY_SIZE(chardevs); ++i)
device_create(aoe_class, NULL,
MKDEV(AOE_MAJOR, chardevs[i].minor), NULL,
chardevs[i].name);
return 0;
}
void
aoechr_exit(void)
{
int i;
for (i = 0; i < ARRAY_SIZE(chardevs); ++i)
device_destroy(aoe_class, MKDEV(AOE_MAJOR, chardevs[i].minor));
class_destroy(aoe_class);
unregister_chrdev(AOE_MAJOR, "aoechr");
}