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
  12 struct idset {
  13         int num_ssid;
  14         int num_id;
  15         unsigned long bitmap[0];
  16 };
  17
  18 static 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
  23 static 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
  36 void idset_free(struct idset *set)
  37 {
  38         vfree(set);
  39 }
  40
  41 void idset_clear(struct idset *set)
  42 {
  43         memset(set->bitmap, 0, bitmap_size(set->num_ssid, set->num_id));
  44 }
  45
  46 void idset_fill(struct idset *set)
  47 {
  48         memset(set->bitmap, 0xff, bitmap_size(set->num_ssid, set->num_id));
  49 }
  50
  51 static inline void idset_add(struct idset *set, int ssid, int id)
  52 {
  53         set_bit(ssid * set->num_id + id, set->bitmap);
  54 }
  55
  56 static inline void idset_del(struct idset *set, int ssid, int id)
  57 {
  58         clear_bit(ssid * set->num_id + id, set->bitmap);
  59 }
  60
  61 static inline int idset_contains(struct idset *set, int ssid, int id)
  62 {
  63         return test_bit(ssid * set->num_id + id, set->bitmap);
  64 }
  65
  66 static inline int idset_get_first(struct idset *set, int *ssid, int *id)
  67 {
  68         int bitnum;
  69
  70         bitnum = find_first_bit(set->bitmap, set->num_ssid * set->num_id);
  71         if (bitnum >= set->num_ssid * set->num_id)
  72                 return 0;
  73         *ssid = bitnum / set->num_id;
  74         *id = bitnum % set->num_id;
  75         return 1;
  76 }
  77
  78 struct idset *idset_sch_new(void)
  79 {
  80         return idset_new(max_ssid + 1, __MAX_SUBCHANNEL + 1);
  81 }
  82
  83 void idset_sch_add(struct idset *set, struct subchannel_id schid)
  84 {
  85         idset_add(set, schid.ssid, schid.sch_no);
  86 }
  87
  88 void idset_sch_del(struct idset *set, struct subchannel_id schid)
  89 {
  90         idset_del(set, schid.ssid, schid.sch_no);
  91 }
  92
  93 /* Clear ids starting from @schid up to end of subchannel set. */
  94 void idset_sch_del_subseq(struct idset *set, struct subchannel_id schid)
  95 {
  96         int pos = schid.ssid * set->num_id + schid.sch_no;
  97
  98         bitmap_clear(set->bitmap, pos, set->num_id - schid.sch_no);
  99 }
 100
 101 int idset_sch_contains(struct idset *set, struct subchannel_id schid)
 102 {
 103         return idset_contains(set, schid.ssid, schid.sch_no);
 104 }
 105
 106 int idset_sch_get_first(struct idset *set, struct subchannel_id *schid)
 107 {
 108         int ssid = 0;
 109         int id = 0;
 110         int rc;
 111
 112         rc = idset_get_first(set, &ssid, &id);
 113         if (rc) {
 114                 init_subchannel_id(schid);
 115                 schid->ssid = ssid;
 116                 schid->sch_no = id;
 117         }
 118         return rc;
 119 }
 120
 121 int idset_is_empty(struct idset *set)
 122 {
 123         return bitmap_empty(set->bitmap, set->num_ssid * set->num_id);
 124 }
 125
 126 void idset_add_set(struct idset *to, struct idset *from)
 127 {
 128         int len = min(to->num_ssid * to->num_id, from->num_ssid * from->num_id);
 129
 130         bitmap_or(to->bitmap, to->bitmap, from->bitmap, len);
 131 }