cpu_rmap.h

 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_types.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 */
23struct 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
34extern struct cpu_rmap *alloc_cpu_rmap(unsigned int size, gfp_t flags);
35extern void cpu_rmap_get(struct cpu_rmap *rmap);
36extern int cpu_rmap_put(struct cpu_rmap *rmap);
37
38extern int cpu_rmap_add(struct cpu_rmap *rmap, void *obj);
39extern int cpu_rmap_update(struct cpu_rmap *rmap, u16 index,
40			   const struct cpumask *affinity);
41
42static inline u16 cpu_rmap_lookup_index(struct cpu_rmap *rmap, unsigned int cpu)
43{
44	return rmap->near[cpu].index;
45}
46
47static 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 */
58static inline struct cpu_rmap *alloc_irq_cpu_rmap(unsigned int size)
59{
60	return alloc_cpu_rmap(size, GFP_KERNEL);
61}
62extern void free_irq_cpu_rmap(struct cpu_rmap *rmap);
63
64int irq_cpu_rmap_remove(struct cpu_rmap *rmap, int irq);
65extern int irq_cpu_rmap_add(struct cpu_rmap *rmap, int irq);
66
67#endif /* __LINUX_CPU_RMAP_H */