drivers/s390/cio/idset.c

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