root/include/linux/cpu_rmap.h

INCLUDED FROM

DEFINITIONS

1. cpu_rmap_lookup_index
2. cpu_rmap_lookup_obj
3. alloc_irq_cpu_rmap

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