LXR linux/include/linux/cpu

   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 */
  24struct cpu_rmap {
  25        struct kref     refcount;
  26        u16             size, used;
  27        void            **obj;
  28        struct {
  29                u16     index;
  30                u16     dist;
  31        }               near[0];
  32};
  33#define CPU_RMAP_DIST_INF 0xffff
  34
  35extern struct cpu_rmap *alloc_cpu_rmap(unsigned int size, gfp_t flags);
  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
  64extern int irq_cpu_rmap_add(struct cpu_rmap *rmap, int irq);
  65
  66#endif /* __LINUX_CPU_RMAP_H */
  67