include/linux/cpu_rmap.h

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