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
  17 /**
  18  * struct cpu_rmap - CPU affinity reverse-map
  19  * @size: Number of objects to be reverse-mapped
  20  * @used: Number of objects added
  21  * @obj: Pointer to array of object pointers
  22  * @near: For each CPU, the index and distance to the nearest object,
  23  *      based on affinity masks
  24  */
  25 struct cpu_rmap {
  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
  35 extern struct cpu_rmap *alloc_cpu_rmap(unsigned int size, gfp_t flags);
  36
  37 /**
  38  * free_cpu_rmap - free CPU affinity reverse-map
  39  * @rmap: Reverse-map allocated with alloc_cpu_rmap(), or %NULL
  40  */
  41 static inline void free_cpu_rmap(struct cpu_rmap *rmap)
  42 {
  43         kfree(rmap);
  44 }
  45
  46 extern int cpu_rmap_add(struct cpu_rmap *rmap, void *obj);
  47 extern int cpu_rmap_update(struct cpu_rmap *rmap, u16 index,
  48                            const struct cpumask *affinity);
  49
  50 static inline u16 cpu_rmap_lookup_index(struct cpu_rmap *rmap, unsigned int cpu)
  51 {
  52         return rmap->near[cpu].index;
  53 }
  54
  55 static inline void *cpu_rmap_lookup_obj(struct cpu_rmap *rmap, unsigned int cpu)
  56 {
  57         return rmap->obj[rmap->near[cpu].index];
  58 }
  59
  60 #ifdef CONFIG_GENERIC_HARDIRQS
  61
  62 /**
  63  * alloc_irq_cpu_rmap - allocate CPU affinity reverse-map for IRQs
  64  * @size: Number of objects to be mapped
  65  *
  66  * Must be called in process context.
  67  */
  68 static inline struct cpu_rmap *alloc_irq_cpu_rmap(unsigned int size)
  69 {
  70         return alloc_cpu_rmap(size, GFP_KERNEL);
  71 }
  72 extern void free_irq_cpu_rmap(struct cpu_rmap *rmap);
  73
  74 extern int irq_cpu_rmap_add(struct cpu_rmap *rmap, int irq);
  75
  76 #endif
  77 #endif /* __LINUX_CPU_RMAP_H */