[PATCH] build kernel/irq/migration.c only if CONFIG_GENERIC_PENDING_IRQ is set

[linux-2.6/x86.git] / drivers / s390 / cio / blacklist.c

/*
 *  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/config.h>
#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 inline void
blacklist_range (range_action action, unsigned int from, unsigned int to,
                 unsigned int ssid)
{
        if (!to)
                to = from;

        if (from > to || to > __MAX_SUBCHANNEL || ssid > __MAX_SSID) {
                printk (KERN_WARNING "Invalid blacklist range "
                        "0.%x.%04x to 0.%x.%04x, skipping\n",
                        ssid, from, ssid, to);
                return;
        }
        for (; from <= to; from++) {
                if (action == add)
                        set_bit (from, bl_dev[ssid]);
                else
                        clear_bit (from, bl_dev[ssid]);
        }
}

/*
 * 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 *ssid, 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 = *ssid = 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;
        *ssid = 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_ssid, to_ssid;

        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) {
                        int j;

                        str += 3;
                        for (j=0; j <= __MAX_SSID; j++)
                                blacklist_range(ra, 0, __MAX_SUBCHANNEL, j);
                } else {
                        int rc;

                        rc = blacklist_busid(&str, &from_id0,
                                             &from_ssid, &from);
                        if (rc)
                                continue;
                        to = from;
                        to_id0 = from_id0;
                        to_ssid = from_ssid;
                        if (*str == '-') {
                                str++;
                                rc = blacklist_busid(&str, &to_id0,
                                                     &to_ssid, &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_ssid != to_ssid)) {
                                printk(KERN_WARNING "invalid cio_ignore range "
                                        "%x.%x.%04x-%x.%x.%04x\n",
                                        from_id0, from_ssid, from,
                                        to_id0, to_ssid, to);
                                continue;
                        }
                        pr_debug("blacklist_setup: adding range "
                                 "from %x.%x.%04x to %x.%x.%04x\n",
                                 from_id0, from_ssid, from, to_id0, to_ssid, to);
                        blacklist_range (ra, from, to, to_ssid);
                }
        }
        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 ssid, int devno)
{
        return test_bit (devno, bl_dev[ssid]);
}

#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 ();
}

/* 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;

        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;
        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 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 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 = create_proc_entry ("cio_ignore", S_IFREG | S_IRUGO | S_IWUSR,
                                   &proc_root);
        if (!entry)
                return -ENOENT;

        entry->proc_fops = &cio_ignore_proc_fops;

        return 0;
}

__initcall (cio_ignore_proc_init);

#endif /* CONFIG_PROC_FS */