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
* $Revision: 1.35 $
*
* Copyright (C) 1999-2002 IBM Deutschland Entwicklung GmbH,
* IBM Corporation
* Author(s): Ingo Adlung (adlung@de.ibm.com)
* Cornelia Huck (cohuck@de.ibm.com)
* Arnd Bergmann (arndb@de.ibm.com)
*/
#include <linux/config.h>
#include <linux/init.h>
#include <linux/vmalloc.h>
#include <linux/slab.h>
#include <linux/proc_fs.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 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[__BL_DEV_WORDS];
typedef enum {add, free} range_action;
/*
* Function: blacklist_range
* (Un-)blacklist the devices from-to
*/
static inline void
blacklist_range (range_action action, unsigned int from, unsigned int to)
{
if (!to)
to = from;
if (from > to || to > __MAX_SUBCHANNEL) {
printk (KERN_WARNING "Invalid blacklist range "
"0x%04x to 0x%04x, skipping\n", from, to);
return;
}
for (; from <= to; from++) {
if (action == add)
set_bit (from, bl_dev);
else
clear_bit (from, bl_dev);
}
}
/*
* Function: blacklist_busid
* Get devno/busid from given string.
* Shamelessly grabbed from dasd_devmap.c.
*/
static inline int
blacklist_busid(char **str, int *id0, int *id1, int *devno)
{
int val, old_style;
char *sav;
sav = *str;
/* check for leading '0x' */
old_style = 0;
if ((*str)[0] == '0' && (*str)[1] == 'x') {
*str += 2;
old_style = 1;
}
if (!isxdigit((*str)[0])) /* We require at least one hex digit */
goto confused;
val = simple_strtoul(*str, str, 16);
if (old_style || (*str)[0] != '.') {
*id0 = *id1 = 0;
if (val < 0 || val > 0xffff)
goto confused;
*devno = val;
if ((*str)[0] != ',' && (*str)[0] != '-' &&
(*str)[0] != '\n' && (*str)[0] != '\0')
goto confused;
return 0;
}
/* New style x.y.z busid */
if (val < 0 || val > 0xff)
goto confused;
*id0 = val;
(*str)++;
if (!isxdigit((*str)[0])) /* We require at least one hex digit */
goto confused;
val = simple_strtoul(*str, str, 16);
if (val < 0 || val > 0xff || (*str)++[0] != '.')
goto confused;
*id1 = val;
if (!isxdigit((*str)[0])) /* We require at least one hex digit */
goto confused;
val = simple_strtoul(*str, str, 16);
if (val < 0 || val > 0xffff)
goto confused;
*devno = val;
if ((*str)[0] != ',' && (*str)[0] != '-' &&
(*str)[0] != '\n' && (*str)[0] != '\0')
goto confused;
return 0;
confused:
strsep(str, ",\n");
printk(KERN_WARNING "Invalid cio_ignore parameter '%s'\n", sav);
return 1;
}
static inline int
blacklist_parse_parameters (char *str, range_action action)
{
unsigned int from, to, from_id0, to_id0, from_id1, to_id1;
while (*str != 0 && *str != '\n') {
range_action ra = action;
while(*str == ',')
str++;
if (*str == '!') {
ra = !action;
++str;
}
/*
* Since we have to parse the proc commands and the
* kernel arguments we have to check four cases
*/
if (strncmp(str,"all,",4) == 0 || strcmp(str,"all") == 0 ||
strncmp(str,"all\n",4) == 0 || strncmp(str,"all ",4) == 0) {
from = 0;
to = __MAX_SUBCHANNEL;
str += 3;
} else {
int rc;
rc = blacklist_busid(&str, &from_id0,
&from_id1, &from);
if (rc)
continue;
to = from;
to_id0 = from_id0;
to_id1 = from_id1;
if (*str == '-') {
str++;
rc = blacklist_busid(&str, &to_id0,
&to_id1, &to);
if (rc)
continue;
}
if (*str == '-') {
printk(KERN_WARNING "invalid cio_ignore "
"parameter '%s'\n",
strsep(&str, ",\n"));
continue;
}
if ((from_id0 != to_id0) || (from_id1 != to_id1)) {
printk(KERN_WARNING "invalid cio_ignore range "
"%x.%x.%04x-%x.%x.%04x\n",
from_id0, from_id1, from,
to_id0, to_id1, to);
continue;
}
}
/* FIXME: ignoring id0 and id1 here. */
pr_debug("blacklist_setup: adding range "
"from 0.0.%04x to 0.0.%04x\n", from, to);
blacklist_range (ra, from, to);
}
return 1;
}
/* Parsing the commandline for blacklist parameters, e.g. to blacklist
* bus ids 0.0.1234, 0.0.1235 and 0.0.1236, you could use any of:
* - cio_ignore=1234-1236
* - cio_ignore=0x1234-0x1235,1236
* - cio_ignore=0x1234,1235-1236
* - cio_ignore=1236 cio_ignore=1234-0x1236
* - cio_ignore=1234 cio_ignore=1236 cio_ignore=0x1235
* - cio_ignore=0.0.1234-0.0.1236
* - cio_ignore=0.0.1234,0x1235,1236
* - ...
*/
static int __init
blacklist_setup (char *str)
{
CIO_MSG_EVENT(6, "Reading blacklist parameters\n");
return blacklist_parse_parameters (str, add);
}
__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 devno)
{
return test_bit (devno, bl_dev);
}
#ifdef CONFIG_PROC_FS
static int
__s390_redo_validation(struct subchannel_id schid, void *data)
{
int ret;
struct subchannel *sch;
sch = get_subchannel_by_schid(schid);
if (sch) {
/* Already known. */
put_device(&sch->dev);
return 0;
}
ret = css_probe_device(schid);
if (ret == -ENXIO)
return ret; /* We're through. */
if (ret == -ENOMEM)
/* Stop validation for now. Bad, but no need for a panic. */
return ret;
return 0;
}
/*
* Function: s390_redo_validation
* Look for no longer blacklisted devices
* FIXME: there must be a better way to do this */
static inline void
s390_redo_validation (void)
{
CIO_TRACE_EVENT (0, "redoval");
for_each_subchannel(__s390_redo_validation, NULL);
}
/*
* Function: blacklist_parse_proc_parameters
* parse the stuff which is piped to /proc/cio_ignore
*/
static inline void
blacklist_parse_proc_parameters (char *buf)
{
if (strncmp (buf, "free ", 5) == 0) {
blacklist_parse_parameters (buf + 5, free);
} else if (strncmp (buf, "add ", 4) == 0) {
/*
* We don't need to check for known devices since
* css_probe_device will handle this correctly.
*/
blacklist_parse_parameters (buf + 4, add);
} else {
printk (KERN_WARNING "cio_ignore: Parse error; \n"
KERN_WARNING "try using 'free all|<devno-range>,"
"<devno-range>,...'\n"
KERN_WARNING "or 'add <devno-range>,"
"<devno-range>,...'\n");
return;
}
s390_redo_validation ();
}
/* FIXME: These should be real bus ids and not home-grown ones! */
static int cio_ignore_read (char *page, char **start, off_t off,
int count, int *eof, void *data)
{
const unsigned int entry_size = 18; /* "0.0.ABCD-0.0.EFGH\n" */
long devno;
int len;
len = 0;
for (devno = off; /* abuse the page variable
* as counter, see fs/proc/generic.c */
devno < __MAX_SUBCHANNEL && len + entry_size < count; devno++) {
if (!test_bit(devno, bl_dev))
continue;
len += sprintf(page + len, "0.0.%04lx", devno);
if (test_bit(devno + 1, bl_dev)) { /* print range */
while (++devno < __MAX_SUBCHANNEL)
if (!test_bit(devno, bl_dev))
break;
len += sprintf(page + len, "-0.0.%04lx", --devno);
}
len += sprintf(page + len, "\n");
}
if (devno < __MAX_SUBCHANNEL)
*eof = 1;
*start = (char *) (devno - off); /* number of checked entries */
return len;
}
static int cio_ignore_write(struct file *file, const char __user *user_buf,
unsigned long user_len, void *data)
{
char *buf;
if (user_len > 65536)
user_len = 65536;
buf = vmalloc (user_len + 1); /* maybe better use the stack? */
if (buf == NULL)
return -ENOMEM;
if (strncpy_from_user (buf, user_buf, user_len) < 0) {
vfree (buf);
return -EFAULT;
}
buf[user_len] = '\0';
blacklist_parse_proc_parameters (buf);
vfree (buf);
return user_len;
}
static int
cio_ignore_proc_init (void)
{
struct proc_dir_entry *entry;
entry = create_proc_entry ("cio_ignore", S_IFREG | S_IRUGO | S_IWUSR,
&proc_root);
if (!entry)
return 0;
entry->read_proc = cio_ignore_read;
entry->write_proc = cio_ignore_write;
return 1;
}
__initcall (cio_ignore_proc_init);
#endif /* CONFIG_PROC_FS */