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/slab.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 __BITOPS_WORDS(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 = kzalloc(sizeof(struct idset) + bitmap_size(num_ssid, num_id), 29 GFP_KERNEL); 30 if (set) { 31 set->num_ssid = num_ssid; 32 set->num_id = num_id; 33 } 34 return set; 35 } 36 37 void idset_free(struct idset *set) 38 { 39 kfree(set); 40 } 41 42 void idset_clear(struct idset *set) 43 { 44 memset(set->bitmap, 0, bitmap_size(set->num_ssid, set->num_id)); 45 } 46 47 void idset_fill(struct idset *set) 48 { 49 memset(set->bitmap, 0xff, bitmap_size(set->num_ssid, set->num_id)); 50 } 51 52 static inline void idset_add(struct idset *set, int ssid, int id) 53 { 54 set_bit(ssid * set->num_id + id, set->bitmap); 55 } 56 57 static inline void idset_del(struct idset *set, int ssid, int id) 58 { 59 clear_bit(ssid * set->num_id + id, set->bitmap); 60 } 61 62 static 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 67 static 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 79 struct idset *idset_sch_new(void) 80 { 81 return idset_new(__MAX_SSID + 1, __MAX_SUBCHANNEL + 1); 82 } 83 84 void idset_sch_add(struct idset *set, struct subchannel_id schid) 85 { 86 idset_add(set, schid.ssid, schid.sch_no); 87 } 88 89 void idset_sch_del(struct idset *set, struct subchannel_id schid) 90 { 91 idset_del(set, schid.ssid, schid.sch_no); 92 } 93 94 int idset_sch_contains(struct idset *set, struct subchannel_id schid) 95 { 96 return idset_contains(set, schid.ssid, schid.sch_no); 97 } 98 99 int 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