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798ab48e KO |
1 | #ifndef __PERCPU_IDA_H__ |
2 | #define __PERCPU_IDA_H__ | |
3 | ||
4 | #include <linux/types.h> | |
5 | #include <linux/bitops.h> | |
6 | #include <linux/init.h> | |
7 | #include <linux/spinlock_types.h> | |
8 | #include <linux/wait.h> | |
9 | #include <linux/cpumask.h> | |
10 | ||
11 | struct percpu_ida_cpu; | |
12 | ||
13 | struct percpu_ida { | |
14 | /* | |
15 | * number of tags available to be allocated, as passed to | |
16 | * percpu_ida_init() | |
17 | */ | |
18 | unsigned nr_tags; | |
19 | ||
20 | struct percpu_ida_cpu __percpu *tag_cpu; | |
21 | ||
22 | /* | |
23 | * Bitmap of cpus that (may) have tags on their percpu freelists: | |
24 | * steal_tags() uses this to decide when to steal tags, and which cpus | |
25 | * to try stealing from. | |
26 | * | |
27 | * It's ok for a freelist to be empty when its bit is set - steal_tags() | |
28 | * will just keep looking - but the bitmap _must_ be set whenever a | |
29 | * percpu freelist does have tags. | |
30 | */ | |
31 | cpumask_t cpus_have_tags; | |
32 | ||
33 | struct { | |
34 | spinlock_t lock; | |
35 | /* | |
36 | * When we go to steal tags from another cpu (see steal_tags()), | |
37 | * we want to pick a cpu at random. Cycling through them every | |
38 | * time we steal is a bit easier and more or less equivalent: | |
39 | */ | |
40 | unsigned cpu_last_stolen; | |
41 | ||
42 | /* For sleeping on allocation failure */ | |
43 | wait_queue_head_t wait; | |
44 | ||
45 | /* | |
46 | * Global freelist - it's a stack where nr_free points to the | |
47 | * top | |
48 | */ | |
49 | unsigned nr_free; | |
50 | unsigned *freelist; | |
51 | } ____cacheline_aligned_in_smp; | |
52 | }; | |
53 | ||
54 | int percpu_ida_alloc(struct percpu_ida *pool, gfp_t gfp); | |
55 | void percpu_ida_free(struct percpu_ida *pool, unsigned tag); | |
56 | ||
57 | void percpu_ida_destroy(struct percpu_ida *pool); | |
58 | int percpu_ida_init(struct percpu_ida *pool, unsigned long nr_tags); | |
59 | ||
60 | #endif /* __PERCPU_IDA_H__ */ |