drivers/s390/cio/idset.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *    Copyright IBM Corp. 2007, 2012
   4  *    Author(s): Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
   5  */
   6
   7 #include <linux/vmalloc.h>
   8 #include <linux/bitmap.h>
   9 #include <linux/bitops.h>
  10 #include "idset.h"
  11 #include "css.h"
  12
  13 struct idset {
  14         int num_ssid;
  15         int num_id;
  16         unsigned long bitmap[0];
  17 };
  18
  19 static inline unsigned long bitmap_size(int num_ssid, int num_id)
  20 {
  21         return BITS_TO_LONGS(num_ssid * num_id) * sizeof(unsigned long);
  22 }
  23
  24 static 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
  37 void idset_free(struct idset *set)
  38 {
  39         vfree(set);
  40 }
  41
  42 void idset_fill(struct idset *set)
  43 {
  44         memset(set->bitmap, 0xff, bitmap_size(set->num_ssid, set->num_id));
  45 }
  46
  47 static inline void idset_add(struct idset *set, int ssid, int id)
  48 {
  49         set_bit(ssid * set->num_id + id, set->bitmap);
  50 }
  51
  52 static inline void idset_del(struct idset *set, int ssid, int id)
  53 {
  54         clear_bit(ssid * set->num_id + id, set->bitmap);
  55 }
  56
  57 static inline int idset_contains(struct idset *set, int ssid, int id)
  58 {
  59         return test_bit(ssid * set->num_id + id, set->bitmap);
  60 }
  61
  62 static inline int idset_get_first(struct idset *set, int *ssid, int *id)
  63 {
  64         int bitnum;
  65
  66         bitnum = find_first_bit(set->bitmap, set->num_ssid * set->num_id);
  67         if (bitnum >= set->num_ssid * set->num_id)
  68                 return 0;
  69         *ssid = bitnum / set->num_id;
  70         *id = bitnum % set->num_id;
  71         return 1;
  72 }
  73
  74 struct idset *idset_sch_new(void)
  75 {
  76         return idset_new(max_ssid + 1, __MAX_SUBCHANNEL + 1);
  77 }
  78
  79 void idset_sch_add(struct idset *set, struct subchannel_id schid)
  80 {
  81         idset_add(set, schid.ssid, schid.sch_no);
  82 }
  83
  84 void idset_sch_del(struct idset *set, struct subchannel_id schid)
  85 {
  86         idset_del(set, schid.ssid, schid.sch_no);
  87 }
  88
  89 /* Clear ids starting from @schid up to end of subchannel set. */
  90 void idset_sch_del_subseq(struct idset *set, struct subchannel_id schid)
  91 {
  92         int pos = schid.ssid * set->num_id + schid.sch_no;
  93
  94         bitmap_clear(set->bitmap, pos, set->num_id - schid.sch_no);
  95 }
  96
  97 int idset_sch_contains(struct idset *set, struct subchannel_id schid)
  98 {
  99         return idset_contains(set, schid.ssid, schid.sch_no);
 100 }
 101
 102 int idset_is_empty(struct idset *set)
 103 {
 104         return bitmap_empty(set->bitmap, set->num_ssid * set->num_id);
 105 }
 106
 107 void idset_add_set(struct idset *to, struct idset *from)
 108 {
 109         int len = min(to->num_ssid * to->num_id, from->num_ssid * from->num_id);
 110
 111         bitmap_or(to->bitmap, to->bitmap, from->bitmap, len);
 112 }