linux/drivers/s390/cio/blacklist.c

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/*
* drivers/s390/cio/blacklist.c
* S/390 common I/O routines -- blacklisting of specific devices
*
* Copyright (C) 1999-2002 IBM Deutschland Entwicklung GmbH,
* IBM Corporation
* Author(s): Ingo Adlung (adlung@de.ibm.com)
* Cornelia Huck (cornelia.huck@de.ibm.com)
* Arnd Bergmann (arndb@de.ibm.com)
*/
#include <linux/init.h>
#include <linux/vmalloc.h>
#include <linux/slab.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/ctype.h>
#include <linux/device.h>
#include <asm/cio.h>
#include <asm/uaccess.h>
#include "blacklist.h"
#include "cio.h"
#include "cio_debug.h"
#include "css.h"
/*
* "Blacklisting" of certain devices:
* Device numbers given in the commandline as cio_ignore=... won't be known
* to Linux.
*
* These can be single devices or ranges of devices
*/
/* 65536 bits for each set to indicate if a devno is blacklisted or not */
#define __BL_DEV_WORDS ((__MAX_SUBCHANNEL + (8*sizeof(long) - 1)) / \
(8*sizeof(long)))
static unsigned long bl_dev[__MAX_SSID + 1][__BL_DEV_WORDS];
typedef enum {add, free} range_action;
/*
* Function: blacklist_range
* (Un-)blacklist the devices from-to
*/
static int blacklist_range(range_action action, unsigned int from_ssid,
unsigned int to_ssid, unsigned int from,
unsigned int to, int msgtrigger)
{
if ((from_ssid > to_ssid) || ((from_ssid == to_ssid) && (from > to))) {
if (msgtrigger)
printk(KERN_WARNING "cio: Invalid cio_ignore range "
"0.%x.%04x-0.%x.%04x\n", from_ssid, from,
to_ssid, to);
return 1;
}
while ((from_ssid < to_ssid) || ((from_ssid == to_ssid) &&
(from <= to))) {
if (action == add)
set_bit(from, bl_dev[from_ssid]);
else
clear_bit(from, bl_dev[from_ssid]);
from++;
if (from > __MAX_SUBCHANNEL) {
from_ssid++;
from = 0;
}
}
return 0;
}
static int pure_hex(char **cp, unsigned int *val, int min_digit,
int max_digit, int max_val)
{
int diff;
unsigned int value;
diff = 0;
*val = 0;
while (isxdigit(**cp) && (diff <= max_digit)) {
if (isdigit(**cp))
value = **cp - '0';
else
value = tolower(**cp) - 'a' + 10;
*val = *val * 16 + value;
(*cp)++;
diff++;
}
if ((diff < min_digit) || (diff > max_digit) || (*val > max_val))
return 1;
return 0;
}
static int parse_busid(char *str, int *cssid, int *ssid, int *devno,
int msgtrigger)
{
char *str_work;
int val, rc, ret;
rc = 1;
if (*str == '\0')
goto out;
/* old style */
str_work = str;
val = simple_strtoul(str, &str_work, 16);
if (*str_work == '\0') {
if (val <= __MAX_SUBCHANNEL) {
*devno = val;
*ssid = 0;
*cssid = 0;
rc = 0;
}
goto out;
}
/* new style */
str_work = str;
ret = pure_hex(&str_work, cssid, 1, 2, __MAX_CSSID);
if (ret || (str_work[0] != '.'))
goto out;
str_work++;
ret = pure_hex(&str_work, ssid, 1, 1, __MAX_SSID);
if (ret || (str_work[0] != '.'))
goto out;
str_work++;
ret = pure_hex(&str_work, devno, 4, 4, __MAX_SUBCHANNEL);
if (ret || (str_work[0] != '\0'))
goto out;
rc = 0;
out:
if (rc && msgtrigger)
printk(KERN_WARNING "cio: Invalid cio_ignore device '%s'\n",
str);
return rc;
}
static int blacklist_parse_parameters(char *str, range_action action,
int msgtrigger)
{
int from_cssid, to_cssid, from_ssid, to_ssid, from, to;
int rc, totalrc;
char *parm;
range_action ra;
totalrc = 0;
while ((parm = strsep(&str, ","))) {
rc = 0;
ra = action;
if (*parm == '!') {
if (ra == add)
ra = free;
else
ra = add;
parm++;
}
if (strcmp(parm, "all") == 0) {
from_cssid = 0;
from_ssid = 0;
from = 0;
to_cssid = __MAX_CSSID;
to_ssid = __MAX_SSID;
to = __MAX_SUBCHANNEL;
} else {
rc = parse_busid(strsep(&parm, "-"), &from_cssid,
&from_ssid, &from, msgtrigger);
if (!rc) {
if (parm != NULL)
rc = parse_busid(parm, &to_cssid,
&to_ssid, &to,
msgtrigger);
else {
to_cssid = from_cssid;
to_ssid = from_ssid;
to = from;
}
}
}
if (!rc) {
rc = blacklist_range(ra, from_ssid, to_ssid, from, to,
msgtrigger);
if (rc)
totalrc = 1;
} else
totalrc = 1;
}
return totalrc;
}
static int __init
blacklist_setup (char *str)
{
CIO_MSG_EVENT(6, "Reading blacklist parameters\n");
if (blacklist_parse_parameters(str, add, 1))
return 0;
return 1;
}
__setup ("cio_ignore=", blacklist_setup);
/* Checking if devices are blacklisted */
/*
* Function: is_blacklisted
* Returns 1 if the given devicenumber can be found in the blacklist,
* otherwise 0.
* Used by validate_subchannel()
*/
int
is_blacklisted (int ssid, int devno)
{
return test_bit (devno, bl_dev[ssid]);
}
#ifdef CONFIG_PROC_FS
/*
* Function: blacklist_parse_proc_parameters
* parse the stuff which is piped to /proc/cio_ignore
*/
static int blacklist_parse_proc_parameters(char *buf)
{
int rc;
char *parm;
parm = strsep(&buf, " ");
if (strcmp("free", parm) == 0)
rc = blacklist_parse_parameters(buf, free, 0);
else if (strcmp("add", parm) == 0)
rc = blacklist_parse_parameters(buf, add, 0);
else
return 1;
css_schedule_reprobe();
return rc;
}
/* Iterator struct for all devices. */
struct ccwdev_iter {
int devno;
int ssid;
int in_range;
};
static void *
cio_ignore_proc_seq_start(struct seq_file *s, loff_t *offset)
{
struct ccwdev_iter *iter;
if (*offset >= (__MAX_SUBCHANNEL + 1) * (__MAX_SSID + 1))
return NULL;
iter = kzalloc(sizeof(struct ccwdev_iter), GFP_KERNEL);
if (!iter)
return ERR_PTR(-ENOMEM);
iter->ssid = *offset / (__MAX_SUBCHANNEL + 1);
iter->devno = *offset % (__MAX_SUBCHANNEL + 1);
return iter;
}
static void
cio_ignore_proc_seq_stop(struct seq_file *s, void *it)
{
if (!IS_ERR(it))
kfree(it);
}
static void *
cio_ignore_proc_seq_next(struct seq_file *s, void *it, loff_t *offset)
{
struct ccwdev_iter *iter;
if (*offset >= (__MAX_SUBCHANNEL + 1) * (__MAX_SSID + 1))
return NULL;
iter = it;
if (iter->devno == __MAX_SUBCHANNEL) {
iter->devno = 0;
iter->ssid++;
if (iter->ssid > __MAX_SSID)
return NULL;
} else
iter->devno++;
(*offset)++;
return iter;
}
static int
cio_ignore_proc_seq_show(struct seq_file *s, void *it)
{
struct ccwdev_iter *iter;
iter = it;
if (!is_blacklisted(iter->ssid, iter->devno))
/* Not blacklisted, nothing to output. */
return 0;
if (!iter->in_range) {
/* First device in range. */
if ((iter->devno == __MAX_SUBCHANNEL) ||
!is_blacklisted(iter->ssid, iter->devno + 1))
/* Singular device. */
return seq_printf(s, "0.%x.%04x\n",
iter->ssid, iter->devno);
iter->in_range = 1;
return seq_printf(s, "0.%x.%04x-", iter->ssid, iter->devno);
}
if ((iter->devno == __MAX_SUBCHANNEL) ||
!is_blacklisted(iter->ssid, iter->devno + 1)) {
/* Last device in range. */
iter->in_range = 0;
return seq_printf(s, "0.%x.%04x\n", iter->ssid, iter->devno);
}
return 0;
}
static ssize_t
cio_ignore_write(struct file *file, const char __user *user_buf,
size_t user_len, loff_t *offset)
{
char *buf;
size_t i;
ssize_t rc, ret;
if (*offset)
return -EINVAL;
if (user_len > 65536)
user_len = 65536;
buf = vmalloc (user_len + 1); /* maybe better use the stack? */
if (buf == NULL)
return -ENOMEM;
memset(buf, 0, user_len + 1);
if (strncpy_from_user (buf, user_buf, user_len) < 0) {
rc = -EFAULT;
goto out_free;
}
i = user_len - 1;
while ((i >= 0) && (isspace(buf[i]) || (buf[i] == 0))) {
buf[i] = '\0';
i--;
}
ret = blacklist_parse_proc_parameters(buf);
if (ret)
rc = -EINVAL;
else
rc = user_len;
out_free:
vfree (buf);
return rc;
}
static const struct seq_operations cio_ignore_proc_seq_ops = {
.start = cio_ignore_proc_seq_start,
.stop = cio_ignore_proc_seq_stop,
.next = cio_ignore_proc_seq_next,
.show = cio_ignore_proc_seq_show,
};
static int
cio_ignore_proc_open(struct inode *inode, struct file *file)
{
return seq_open(file, &cio_ignore_proc_seq_ops);
}
static const struct file_operations cio_ignore_proc_fops = {
.open = cio_ignore_proc_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
.write = cio_ignore_write,
};
static int
cio_ignore_proc_init (void)
{
struct proc_dir_entry *entry;
entry = proc_create("cio_ignore", S_IFREG | S_IRUGO | S_IWUSR, NULL,
&cio_ignore_proc_fops);
if (!entry)
return -ENOENT;
return 0;
}
__initcall (cio_ignore_proc_init);
#endif /* CONFIG_PROC_FS */