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  * @used: Number of objects added
20  * @obj: Pointer to array of object pointers
21  * @near: For each CPU, the index and distance to the nearest object,
22  *      based on affinity masks
23  */
24 struct cpu_rmap {
25 	struct kref	refcount;
26 	u16		size, used;
27 	void		**obj;
28 	struct {
29 		u16	index;
30 		u16	dist;
31 	}		near[];
32 };
33 #define CPU_RMAP_DIST_INF 0xffff
34 
35 extern struct cpu_rmap *alloc_cpu_rmap(unsigned int size, gfp_t flags);
36 extern int cpu_rmap_put(struct cpu_rmap *rmap);
37 
38 extern int cpu_rmap_add(struct cpu_rmap *rmap, void *obj);
39 extern int cpu_rmap_update(struct cpu_rmap *rmap, u16 index,
40 			   const struct cpumask *affinity);
41 
cpu_rmap_lookup_index(struct cpu_rmap * rmap,unsigned int cpu)42 static inline u16 cpu_rmap_lookup_index(struct cpu_rmap *rmap, unsigned int cpu)
43 {
44 	return rmap->near[cpu].index;
45 }
46 
cpu_rmap_lookup_obj(struct cpu_rmap * rmap,unsigned int cpu)47 static inline void *cpu_rmap_lookup_obj(struct cpu_rmap *rmap, unsigned int cpu)
48 {
49 	return rmap->obj[rmap->near[cpu].index];
50 }
51 
52 /**
53  * alloc_irq_cpu_rmap - allocate CPU affinity reverse-map for IRQs
54  * @size: Number of objects to be mapped
55  *
56  * Must be called in process context.
57  */
alloc_irq_cpu_rmap(unsigned int size)58 static inline struct cpu_rmap *alloc_irq_cpu_rmap(unsigned int size)
59 {
60 	return alloc_cpu_rmap(size, GFP_KERNEL);
61 }
62 extern void free_irq_cpu_rmap(struct cpu_rmap *rmap);
63 
64 extern int irq_cpu_rmap_add(struct cpu_rmap *rmap, int irq);
65 
66 #endif /* __LINUX_CPU_RMAP_H */
67