idset.c

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/*
 *    Copyright IBM Corp. 2007, 2012
 *    Author(s): Peter Oberparleiter <[email protected]>
 */

#include <linux/vmalloc.h>
#include <linux/bitmap.h>
#include <linux/bitops.h>
#include "idset.h"
#include "css.h"

struct idset {
    int num_ssid;
    int num_id;
    unsigned long bitmap[0];
};

static inline unsigned long bitmap_size(int num_ssid, int num_id)
{
    return __BITOPS_WORDS(num_ssid * num_id) * sizeof(unsigned long);
}

static struct idset *idset_new(int num_ssid, int num_id)
{
    struct idset *set;

    set = vmalloc(sizeof(struct idset) + bitmap_size(num_ssid, num_id));
    if (set) {
        set->num_ssid = num_ssid;
        set->num_id = num_id;
        memset(set->bitmap, 0, bitmap_size(num_ssid, num_id));
    }
    return set;
}

void idset_free(struct idset *set)
{
    vfree(set);
}

void idset_clear(struct idset *set)
{
    memset(set->bitmap, 0, bitmap_size(set->num_ssid, set->num_id));
}

void idset_fill(struct idset *set)
{
    memset(set->bitmap, 0xff, bitmap_size(set->num_ssid, set->num_id));
}

static inline void idset_add(struct idset *set, int ssid, int id)
{
    set_bit(ssid * set->num_id + id, set->bitmap);
}

static inline void idset_del(struct idset *set, int ssid, int id)
{
    clear_bit(ssid * set->num_id + id, set->bitmap);
}

static inline int idset_contains(struct idset *set, int ssid, int id)
{
    return test_bit(ssid * set->num_id + id, set->bitmap);
}

static inline int idset_get_first(struct idset *set, int *ssid, int *id)
{
    int bitnum;

    bitnum = find_first_bit(set->bitmap, set->num_ssid * set->num_id);
    if (bitnum >= set->num_ssid * set->num_id)
        return 0;
    *ssid = bitnum / set->num_id;
    *id = bitnum % set->num_id;
    return 1;
}

struct idset *idset_sch_new(void)
{
    return idset_new(max_ssid + 1, __MAX_SUBCHANNEL + 1);
}

void idset_sch_add(struct idset *set, struct subchannel_id schid)
{
    idset_add(set, schid.ssid, schid.sch_no);
}

void idset_sch_del(struct idset *set, struct subchannel_id schid)
{
    idset_del(set, schid.ssid, schid.sch_no);
}

/* Clear ids starting from @schid up to end of subchannel set. */
void idset_sch_del_subseq(struct idset *set, struct subchannel_id schid)
{
    int pos = schid.ssid * set->num_id + schid.sch_no;

    bitmap_clear(set->bitmap, pos, set->num_id - schid.sch_no);
}

int idset_sch_contains(struct idset *set, struct subchannel_id schid)
{
    return idset_contains(set, schid.ssid, schid.sch_no);
}

int idset_sch_get_first(struct idset *set, struct subchannel_id *schid)
{
    int ssid = 0;
    int id = 0;
    int rc;

    rc = idset_get_first(set, &ssid, &id);
    if (rc) {
        init_subchannel_id(schid);
        schid->ssid = ssid;
        schid->sch_no = id;
    }
    return rc;
}

int idset_is_empty(struct idset *set)
{
    return bitmap_empty(set->bitmap, set->num_ssid * set->num_id);
}

void idset_add_set(struct idset *to, struct idset *from)
{
    int len = min(to->num_ssid * to->num_id, from->num_ssid * from->num_id);

    bitmap_or(to->bitmap, to->bitmap, from->bitmap, len);
}