aboutsummaryrefslogtreecommitdiffstats
path: root/include/linux
diff options
context:
space:
mode:
Diffstat (limited to 'include/linux')
-rw-r--r--include/linux/idr.h29
1 files changed, 29 insertions, 0 deletions
diff --git a/include/linux/idr.h b/include/linux/idr.h
index 826803449db7..915572fa030b 100644
--- a/include/linux/idr.h
+++ b/include/linux/idr.h
@@ -83,4 +83,33 @@ void idr_remove(struct idr *idp, int id);
83void idr_destroy(struct idr *idp); 83void idr_destroy(struct idr *idp);
84void idr_init(struct idr *idp); 84void idr_init(struct idr *idp);
85 85
86
87/*
88 * IDA - IDR based id allocator, use when translation from id to
89 * pointer isn't necessary.
90 */
91#define IDA_CHUNK_SIZE 128 /* 128 bytes per chunk */
92#define IDA_BITMAP_LONGS (128 / sizeof(long) - 1)
93#define IDA_BITMAP_BITS (IDA_BITMAP_LONGS * sizeof(long) * 8)
94
95struct ida_bitmap {
96 long nr_busy;
97 unsigned long bitmap[IDA_BITMAP_LONGS];
98};
99
100struct ida {
101 struct idr idr;
102 struct ida_bitmap *free_bitmap;
103};
104
105#define IDA_INIT(name) { .idr = IDR_INIT(name), .free_bitmap = NULL, }
106#define DEFINE_IDA(name) struct ida name = IDA_INIT(name)
107
108int ida_pre_get(struct ida *ida, gfp_t gfp_mask);
109int ida_get_new_above(struct ida *ida, int starting_id, int *p_id);
110int ida_get_new(struct ida *ida, int *p_id);
111void ida_remove(struct ida *ida, int id);
112void ida_destroy(struct ida *ida);
113void ida_init(struct ida *ida);
114
86#endif /* __IDR_H__ */ 115#endif /* __IDR_H__ */