LXR linux/drivers/s390/cio/idset.c

   1/*
   2 *  drivers/s390/cio/idset.c
   3 *
   4 *    Copyright IBM Corp. 2007
   5 *    Author(s): Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
   6 */
   7
   8#include <linux/vmalloc.h>
   9#include <linux/bitops.h>
  10#include "idset.h"
  11#include "css.h"
  12
  13struct idset {
  14        int num_ssid;
  15        int num_id;
  16        unsigned long bitmap[0];
  17};
  18
  19static inline unsigned long bitmap_size(int num_ssid, int num_id)
  20{
  21        return __BITOPS_WORDS(num_ssid * num_id) * sizeof(unsigned long);
  22}
  23
  24static struct idset *idset_new(int num_ssid, int num_id)
  25{
  26        struct idset *set;
  27
  28        set = vmalloc(sizeof(struct idset) + bitmap_size(num_ssid, num_id));
  29        if (set) {
  30                set->num_ssid = num_ssid;
  31                set->num_id = num_id;
  32                memset(set->bitmap, 0, bitmap_size(num_ssid, num_id));
  33        }
  34        return set;
  35}
  36
  37void idset_free(struct idset *set)
  38{
  39        vfree(set);
  40}
  41
  42void idset_clear(struct idset *set)
  43{
  44        memset(set->bitmap, 0, bitmap_size(set->num_ssid, set->num_id));
  45}
  46
  47void idset_fill(struct idset *set)
  48{
  49        memset(set->bitmap, 0xff, bitmap_size(set->num_ssid, set->num_id));
  50}
  51
  52static inline void idset_add(struct idset *set, int ssid, int id)
  53{
  54        set_bit(ssid * set->num_id + id, set->bitmap);
  55}
  56
  57static inline void idset_del(struct idset *set, int ssid, int id)
  58{
  59        clear_bit(ssid * set->num_id + id, set->bitmap);
  60}
  61
  62static inline int idset_contains(struct idset *set, int ssid, int id)
  63{
  64        return test_bit(ssid * set->num_id + id, set->bitmap);
  65}
  66
  67static inline int idset_get_first(struct idset *set, int *ssid, int *id)
  68{
  69        int bitnum;
  70
  71        bitnum = find_first_bit(set->bitmap, set->num_ssid * set->num_id);
  72        if (bitnum >= set->num_ssid * set->num_id)
  73                return 0;
  74        *ssid = bitnum / set->num_id;
  75        *id = bitnum % set->num_id;
  76        return 1;
  77}
  78
  79struct idset *idset_sch_new(void)
  80{
  81        return idset_new(max_ssid + 1, __MAX_SUBCHANNEL + 1);
  82}
  83
  84void idset_sch_add(struct idset *set, struct subchannel_id schid)
  85{
  86        idset_add(set, schid.ssid, schid.sch_no);
  87}
  88
  89void idset_sch_del(struct idset *set, struct subchannel_id schid)
  90{
  91        idset_del(set, schid.ssid, schid.sch_no);
  92}
  93
  94int idset_sch_contains(struct idset *set, struct subchannel_id schid)
  95{
  96        return idset_contains(set, schid.ssid, schid.sch_no);
  97}
  98
  99int idset_sch_get_first(struct idset *set, struct subchannel_id *schid)
 100{
 101        int ssid = 0;
 102        int id = 0;
 103        int rc;
 104
 105        rc = idset_get_first(set, &ssid, &id);
 106        if (rc) {
 107                init_subchannel_id(schid);
 108                schid->ssid = ssid;
 109                schid->sch_no = id;
 110        }
 111        return rc;
 112}
 113
 114int idset_is_empty(struct idset *set)
 115{
 116        int bitnum;
 117
 118        bitnum = find_first_bit(set->bitmap, set->num_ssid * set->num_id);
 119        if (bitnum >= set->num_ssid * set->num_id)
 120                return 1;
 121        return 0;
 122}
 123
 124void idset_add_set(struct idset *to, struct idset *from)
 125{
 126        unsigned long i, len;
 127
 128        len = min(__BITOPS_WORDS(to->num_ssid * to->num_id),
 129                  __BITOPS_WORDS(from->num_ssid * from->num_id));
 130        for (i = 0; i < len ; i++)
 131                to->bitmap[i] |= from->bitmap[i];
 132}
 133