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

   1/*
   2 *    Copyright IBM Corp. 2007, 2012
   3 *    Author(s): Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
   4 */
   5
   6#include <linux/vmalloc.h>
   7#include <linux/bitmap.h>
   8#include <linux/bitops.h>
   9#include "idset.h"
  10#include "css.h"
  11
  12struct idset {
  13        int num_ssid;
  14        int num_id;
  15        unsigned long bitmap[0];
  16};
  17
  18static inline unsigned long bitmap_size(int num_ssid, int num_id)
  19{
  20        return BITS_TO_LONGS(num_ssid * num_id) * sizeof(unsigned long);
  21}
  22
  23static struct idset *idset_new(int num_ssid, int num_id)
  24{
  25        struct idset *set;
  26
  27        set = vmalloc(sizeof(struct idset) + bitmap_size(num_ssid, num_id));
  28        if (set) {
  29                set->num_ssid = num_ssid;
  30                set->num_id = num_id;
  31                memset(set->bitmap, 0, bitmap_size(num_ssid, num_id));
  32        }
  33        return set;
  34}
  35
  36void idset_free(struct idset *set)
  37{
  38        vfree(set);
  39}
  40
  41void idset_fill(struct idset *set)
  42{
  43        memset(set->bitmap, 0xff, bitmap_size(set->num_ssid, set->num_id));
  44}
  45
  46static inline void idset_add(struct idset *set, int ssid, int id)
  47{
  48        set_bit(ssid * set->num_id + id, set->bitmap);
  49}
  50
  51static inline void idset_del(struct idset *set, int ssid, int id)
  52{
  53        clear_bit(ssid * set->num_id + id, set->bitmap);
  54}
  55
  56static inline int idset_contains(struct idset *set, int ssid, int id)
  57{
  58        return test_bit(ssid * set->num_id + id, set->bitmap);
  59}
  60
  61static inline int idset_get_first(struct idset *set, int *ssid, int *id)
  62{
  63        int bitnum;
  64
  65        bitnum = find_first_bit(set->bitmap, set->num_ssid * set->num_id);
  66        if (bitnum >= set->num_ssid * set->num_id)
  67                return 0;
  68        *ssid = bitnum / set->num_id;
  69        *id = bitnum % set->num_id;
  70        return 1;
  71}
  72
  73struct idset *idset_sch_new(void)
  74{
  75        return idset_new(max_ssid + 1, __MAX_SUBCHANNEL + 1);
  76}
  77
  78void idset_sch_add(struct idset *set, struct subchannel_id schid)
  79{
  80        idset_add(set, schid.ssid, schid.sch_no);
  81}
  82
  83void idset_sch_del(struct idset *set, struct subchannel_id schid)
  84{
  85        idset_del(set, schid.ssid, schid.sch_no);
  86}
  87
  88/* Clear ids starting from @schid up to end of subchannel set. */
  89void idset_sch_del_subseq(struct idset *set, struct subchannel_id schid)
  90{
  91        int pos = schid.ssid * set->num_id + schid.sch_no;
  92
  93        bitmap_clear(set->bitmap, pos, set->num_id - schid.sch_no);
  94}
  95
  96int idset_sch_contains(struct idset *set, struct subchannel_id schid)
  97{
  98        return idset_contains(set, schid.ssid, schid.sch_no);
  99}
 100
 101int idset_is_empty(struct idset *set)
 102{
 103        return bitmap_empty(set->bitmap, set->num_ssid * set->num_id);
 104}
 105
 106void idset_add_set(struct idset *to, struct idset *from)
 107{
 108        int len = min(to->num_ssid * to->num_id, from->num_ssid * from->num_id);
 109
 110        bitmap_or(to->bitmap, to->bitmap, from->bitmap, len);
 111}
 112