1 #ifndef __LINUX_CPU_RMAP_H
2 #define __LINUX_CPU_RMAP_H
3
4 /*
5 * cpu_rmap.c: CPU affinity reverse-map support
6 * Copyright 2011 Solarflare Communications Inc.
7 *
8 * This program is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License version 2 as published
10 * by the Free Software Foundation, incorporated herein by reference.
11 */
12
13 #include <linux/cpumask.h>
14 #include <linux/gfp.h>
15 #include <linux/slab.h>
16 #include <linux/kref.h>
17
18 /**
19 * struct cpu_rmap - CPU affinity reverse-map
20 * @refcount: kref for object
21 * @size: Number of objects to be reverse-mapped
22 * @used: Number of objects added
23 * @obj: Pointer to array of object pointers
24 * @near: For each CPU, the index and distance to the nearest object,
25 * based on affinity masks
26 */
27 struct cpu_rmap {
28 struct kref refcount;
29 u16 size, used;
30 void **obj;
31 struct {
32 u16 index;
33 u16 dist;
34 } near[0];
35 };
36 #define CPU_RMAP_DIST_INF 0xffff
37
38 extern struct cpu_rmap *alloc_cpu_rmap(unsigned int size, gfp_t flags);
39 extern int cpu_rmap_put(struct cpu_rmap *rmap);
40
41 extern int cpu_rmap_add(struct cpu_rmap *rmap, void *obj);
42 extern int cpu_rmap_update(struct cpu_rmap *rmap, u16 index,
43 const struct cpumask *affinity);
44
cpu_rmap_lookup_index(struct cpu_rmap * rmap,unsigned int cpu)45 static inline u16 cpu_rmap_lookup_index(struct cpu_rmap *rmap, unsigned int cpu)
46 {
47 return rmap->near[cpu].index;
48 }
49
cpu_rmap_lookup_obj(struct cpu_rmap * rmap,unsigned int cpu)50 static inline void *cpu_rmap_lookup_obj(struct cpu_rmap *rmap, unsigned int cpu)
51 {
52 return rmap->obj[rmap->near[cpu].index];
53 }
54
55 /**
56 * alloc_irq_cpu_rmap - allocate CPU affinity reverse-map for IRQs
57 * @size: Number of objects to be mapped
58 *
59 * Must be called in process context.
60 */
alloc_irq_cpu_rmap(unsigned int size)61 static inline struct cpu_rmap *alloc_irq_cpu_rmap(unsigned int size)
62 {
63 return alloc_cpu_rmap(size, GFP_KERNEL);
64 }
65 extern void free_irq_cpu_rmap(struct cpu_rmap *rmap);
66
67 extern int irq_cpu_rmap_add(struct cpu_rmap *rmap, int irq);
68
69 #endif /* __LINUX_CPU_RMAP_H */
70