LXR linux/include/linux/cpu

   1/*
   2 * cpu_rmap.c: CPU affinity reverse-map support
   3 * Copyright 2011 Solarflare Communications Inc.
   4 *
   5 * This program is free software; you can redistribute it and/or modify it
   6 * under the terms of the GNU General Public License version 2 as published
   7 * by the Free Software Foundation, incorporated herein by reference.
   8 */
   9
  10#include <linux/cpumask.h>
  11#include <linux/gfp.h>
  12#include <linux/slab.h>
  13
  14/**
  15 * struct cpu_rmap - CPU affinity reverse-map
  16 * @size: Number of objects to be reverse-mapped
  17 * @used: Number of objects added
  18 * @obj: Pointer to array of object pointers
  19 * @near: For each CPU, the index and distance to the nearest object,
  20 *      based on affinity masks
  21 */
  22struct cpu_rmap {
  23        u16             size, used;
  24        void            **obj;
  25        struct {
  26                u16     index;
  27                u16     dist;
  28        }               near[0];
  29};
  30#define CPU_RMAP_DIST_INF 0xffff
  31
  32extern struct cpu_rmap *alloc_cpu_rmap(unsigned int size, gfp_t flags);
  33
  34/**
  35 * free_cpu_rmap - free CPU affinity reverse-map
  36 * @rmap: Reverse-map allocated with alloc_cpu_rmap(), or %NULL
  37 */
  38static inline void free_cpu_rmap(struct cpu_rmap *rmap)
  39{
  40        kfree(rmap);
  41}
  42
  43extern int cpu_rmap_add(struct cpu_rmap *rmap, void *obj);
  44extern int cpu_rmap_update(struct cpu_rmap *rmap, u16 index,
  45                           const struct cpumask *affinity);
  46
  47static inline u16 cpu_rmap_lookup_index(struct cpu_rmap *rmap, unsigned int cpu)
  48{
  49        return rmap->near[cpu].index;
  50}
  51
  52static inline void *cpu_rmap_lookup_obj(struct cpu_rmap *rmap, unsigned int cpu)
  53{
  54        return rmap->obj[rmap->near[cpu].index];
  55}
  56
  57#ifdef CONFIG_GENERIC_HARDIRQS
  58
  59/**
  60 * alloc_irq_cpu_rmap - allocate CPU affinity reverse-map for IRQs
  61 * @size: Number of objects to be mapped
  62 *
  63 * Must be called in process context.
  64 */
  65static inline struct cpu_rmap *alloc_irq_cpu_rmap(unsigned int size)
  66{
  67        return alloc_cpu_rmap(size, GFP_KERNEL);
  68}
  69extern void free_irq_cpu_rmap(struct cpu_rmap *rmap);
  70
  71extern int irq_cpu_rmap_add(struct cpu_rmap *rmap, int irq);
  72
  73#endif
  74