1 /* SPDX-License-Identifier: GPL-2.0-only */
2 #ifndef __LINUX_CPU_RMAP_H
3 #define __LINUX_CPU_RMAP_H
4
5 /*
6 * cpu_rmap.c: CPU affinity reverse-map support
7 * Copyright 2011 Solarflare Communications Inc.
8 */
9
10 #include <linux/cpumask.h>
11 #include <linux/gfp.h>
12 #include <linux/slab.h>
13 #include <linux/kref.h>
14
15 /**
16 * struct cpu_rmap - CPU affinity reverse-map
17 * @refcount: kref for object
18 * @size: Number of objects to be reverse-mapped
19 * @obj: Pointer to array of object pointers
20 * @near: For each CPU, the index and distance to the nearest object,
21 * based on affinity masks
22 */
23 struct cpu_rmap {
24 struct kref refcount;
25 u16 size;
26 void **obj;
27 struct {
28 u16 index;
29 u16 dist;
30 } near[];
31 };
32 #define CPU_RMAP_DIST_INF 0xffff
33
34 extern struct cpu_rmap *alloc_cpu_rmap(unsigned int size, gfp_t flags);
35 extern int cpu_rmap_put(struct cpu_rmap *rmap);
36
37 extern int cpu_rmap_add(struct cpu_rmap *rmap, void *obj);
38 extern int cpu_rmap_update(struct cpu_rmap *rmap, u16 index,
39 const struct cpumask *affinity);
40
cpu_rmap_lookup_index(struct cpu_rmap * rmap,unsigned int cpu)41 static inline u16 cpu_rmap_lookup_index(struct cpu_rmap *rmap, unsigned int cpu)
42 {
43 return rmap->near[cpu].index;
44 }
45
cpu_rmap_lookup_obj(struct cpu_rmap * rmap,unsigned int cpu)46 static inline void *cpu_rmap_lookup_obj(struct cpu_rmap *rmap, unsigned int cpu)
47 {
48 return rmap->obj[rmap->near[cpu].index];
49 }
50
51 /**
52 * alloc_irq_cpu_rmap - allocate CPU affinity reverse-map for IRQs
53 * @size: Number of objects to be mapped
54 *
55 * Must be called in process context.
56 */
alloc_irq_cpu_rmap(unsigned int size)57 static inline struct cpu_rmap *alloc_irq_cpu_rmap(unsigned int size)
58 {
59 return alloc_cpu_rmap(size, GFP_KERNEL);
60 }
61 extern void free_irq_cpu_rmap(struct cpu_rmap *rmap);
62
63 int irq_cpu_rmap_remove(struct cpu_rmap *rmap, int irq);
64 extern int irq_cpu_rmap_add(struct cpu_rmap *rmap, int irq);
65
66 #endif /* __LINUX_CPU_RMAP_H */
67