modules/genunix/bitset.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#include <mdb/mdb_modapi.h>
#include <sys/bitset.h>

#include "bitset.h"     /* XXX work out ifdef in include file... */

void
bitset_help(void)
{
    mdb_printf("Print the bitset at the address given\n");
}

static void
bitset_free(bitset_t *bs)
{
    if (bs == NULL)
        return;
    if (bs->bs_set && bs->bs_words)
        mdb_free(bs->bs_set, bs->bs_words * sizeof (ulong_t));
    mdb_free(bs, sizeof (*bs));
}

static bitset_t *
bitset_get(uintptr_t bsaddr)
{
    bitset_t    *bs;

    bs = mdb_zalloc(sizeof (*bs), UM_SLEEP);
    if (mdb_vread(bs, sizeof (*bs), bsaddr) == -1) {
        mdb_warn("couldn't read bitset 0x%p", bsaddr);
        bitset_free(bs);
        return (NULL);
    }

    bsaddr = (uintptr_t)bs->bs_set;
    bs->bs_set = mdb_alloc(bs->bs_words * sizeof (ulong_t), UM_SLEEP);
    if (mdb_vread(bs->bs_set,
        bs->bs_words * sizeof (ulong_t), bsaddr) == -1) {
        mdb_warn("couldn't read bitset bs_set 0x%p", bsaddr);
        bitset_free(bs);
        return (NULL);
    }
    return (bs);

}

static int
bitset_highbit(bitset_t *bs)
{
    int high;
    int i;

    if ((bs->bs_set == NULL) || (bs->bs_words == 0))
        return (-1);

    /* move backwards through words */
    for (i = bs->bs_words; i >= 0; i--)
        if (bs->bs_set[i])
            break;
    if (i < 0)
        return (-1);

    /* move backwards through bits */
    high = i << BT_ULSHIFT;
    for (i = BT_NBIPUL - 1; i; i--)
        if (BT_TEST(bs->bs_set, high + i))
            break;
    return (high + i + 1);
}

static int
pow10(int exp)
{
    int res;

    for (res = 1; exp; exp--)
        res *= 10;
    return (res);
}

static int
log10(int val)
{
    int res = 0;

    do {
        res++;
        val /= 10;
    } while (val);
    return (res);
}

/*
 * The following prints a bitset with a 'ruler' that look like this
 *
 *              11111111112222222222333333333344444444445555555555666666666677
 *    012345678901234567890123456789012345678901234567890123456789012345678901
 * xx:........................................................................
 *                                11111111111111111111111111111111111111111111
 *    777777778888888888999999999900000000001111111111222222222233333333334444
 *    234567890123456789012345678901234567890123456789012345678901234567890123
 *    ........................................................................
 *    111111111111111111111111111111111111111111111111111111112222222222222222
 *    444444555555555566666666667777777777888888888899999999990000000000111111
 *    456789012345678901234567890123456789012345678901234567890123456789012345
 *    ........................................................................
 *    2222222222
 *    1111222222
 *    6789012345
 *    ..........
 *
 * to identify individual bits that are set.
 */
static void
bitset_print(bitset_t *bs, char *label, int width)
{
    int val_start;
    int val_max;
    int label_width;
    int ruler_width;
    int v, vm, vi;
    int nl, l;
    int i;
    int p;
    char    c;

    val_start = 0;
    val_max = bitset_highbit(bs) + 1;
    if (val_max <= val_start) {
        mdb_printf("%s: empty-set", label);
        return;
    }

    label_width = strlen(label) + 1;
    ruler_width = width - label_width;

    for (v = val_start; v < val_max; v = vm) {
        if ((v + ruler_width) < val_max)
            vm = v + ruler_width;
        else
            vm = val_max;

        nl = log10(vm) - 1;
        for (l = nl; l >= 0; l--) {
            p = pow10(l);
            for (i = 0; i < label_width; i++)
                mdb_printf(" ");

            for (vi = v; vi < vm; vi++) {
                c = '0' + ((vi / p) % 10);
                if ((l == nl) && (c == '0'))
                    c = ' ';
                mdb_printf("%c", c);
            }

            mdb_printf("\n");
        }

        if (v == val_start) {
            mdb_printf("%s:", label);
        } else {
            for (i = 0; i < label_width; i++)
                mdb_printf(" ");
        }
        for (vi = v; vi < vm; vi++) {
            if (BT_TEST(bs->bs_set, vi))
                mdb_printf("X");
            else
                mdb_printf(".");
        }
        mdb_printf("\n");
    }
}

/*ARGSUSED*/
int
bitset(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
{
    bitset_t    *bs;

    bs = bitset_get(addr);
    if (bs == NULL)
        return (DCMD_ERR);

    bitset_print(bs, "label", 80);
    bitset_free(bs);
    return (DCMD_OK);
}