LXR linux/include/linux/percpu.h

   1#ifndef __LINUX_PERCPU_H
   2#define __LINUX_PERCPU_H
   3
   4#include <linux/mmdebug.h>
   5#include <linux/preempt.h>
   6#include <linux/smp.h>
   7#include <linux/cpumask.h>
   8#include <linux/printk.h>
   9#include <linux/pfn.h>
  10#include <linux/init.h>
  11
  12#include <asm/percpu.h>
  13
  14/* enough to cover all DEFINE_PER_CPUs in modules */
  15#ifdef CONFIG_MODULES
  16#define PERCPU_MODULE_RESERVE           (8 << 10)
  17#else
  18#define PERCPU_MODULE_RESERVE           0
  19#endif
  20
  21/* minimum unit size, also is the maximum supported allocation size */
  22#define PCPU_MIN_UNIT_SIZE              PFN_ALIGN(32 << 10)
  23
  24/*
  25 * Percpu allocator can serve percpu allocations before slab is
  26 * initialized which allows slab to depend on the percpu allocator.
  27 * The following two parameters decide how much resource to
  28 * preallocate for this.  Keep PERCPU_DYNAMIC_RESERVE equal to or
  29 * larger than PERCPU_DYNAMIC_EARLY_SIZE.
  30 */
  31#define PERCPU_DYNAMIC_EARLY_SLOTS      128
  32#define PERCPU_DYNAMIC_EARLY_SIZE       (12 << 10)
  33
  34/*
  35 * PERCPU_DYNAMIC_RESERVE indicates the amount of free area to piggy
  36 * back on the first chunk for dynamic percpu allocation if arch is
  37 * manually allocating and mapping it for faster access (as a part of
  38 * large page mapping for example).
  39 *
  40 * The following values give between one and two pages of free space
  41 * after typical minimal boot (2-way SMP, single disk and NIC) with
  42 * both defconfig and a distro config on x86_64 and 32.  More
  43 * intelligent way to determine this would be nice.
  44 */
  45#if BITS_PER_LONG > 32
  46#define PERCPU_DYNAMIC_RESERVE          (28 << 10)
  47#else
  48#define PERCPU_DYNAMIC_RESERVE          (20 << 10)
  49#endif
  50
  51extern void *pcpu_base_addr;
  52extern const unsigned long *pcpu_unit_offsets;
  53
  54struct pcpu_group_info {
  55        int                     nr_units;       /* aligned # of units */
  56        unsigned long           base_offset;    /* base address offset */
  57        unsigned int            *cpu_map;       /* unit->cpu map, empty
  58                                                 * entries contain NR_CPUS */
  59};
  60
  61struct pcpu_alloc_info {
  62        size_t                  static_size;
  63        size_t                  reserved_size;
  64        size_t                  dyn_size;
  65        size_t                  unit_size;
  66        size_t                  atom_size;
  67        size_t                  alloc_size;
  68        size_t                  __ai_size;      /* internal, don't use */
  69        int                     nr_groups;      /* 0 if grouping unnecessary */
  70        struct pcpu_group_info  groups[];
  71};
  72
  73enum pcpu_fc {
  74        PCPU_FC_AUTO,
  75        PCPU_FC_EMBED,
  76        PCPU_FC_PAGE,
  77
  78        PCPU_FC_NR,
  79};
  80extern const char * const pcpu_fc_names[PCPU_FC_NR];
  81
  82extern enum pcpu_fc pcpu_chosen_fc;
  83
  84typedef void * (*pcpu_fc_alloc_fn_t)(unsigned int cpu, size_t size,
  85                                     size_t align);
  86typedef void (*pcpu_fc_free_fn_t)(void *ptr, size_t size);
  87typedef void (*pcpu_fc_populate_pte_fn_t)(unsigned long addr);
  88typedef int (pcpu_fc_cpu_distance_fn_t)(unsigned int from, unsigned int to);
  89
  90extern struct pcpu_alloc_info * __init pcpu_alloc_alloc_info(int nr_groups,
  91                                                             int nr_units);
  92extern void __init pcpu_free_alloc_info(struct pcpu_alloc_info *ai);
  93
  94extern int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
  95                                         void *base_addr);
  96
  97#ifdef CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK
  98extern int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size,
  99                                size_t atom_size,
 100                                pcpu_fc_cpu_distance_fn_t cpu_distance_fn,
 101                                pcpu_fc_alloc_fn_t alloc_fn,
 102                                pcpu_fc_free_fn_t free_fn);
 103#endif
 104
 105#ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK
 106extern int __init pcpu_page_first_chunk(size_t reserved_size,
 107                                pcpu_fc_alloc_fn_t alloc_fn,
 108                                pcpu_fc_free_fn_t free_fn,
 109                                pcpu_fc_populate_pte_fn_t populate_pte_fn);
 110#endif
 111
 112extern void __percpu *__alloc_reserved_percpu(size_t size, size_t align);
 113extern bool is_kernel_percpu_address(unsigned long addr);
 114
 115#if !defined(CONFIG_SMP) || !defined(CONFIG_HAVE_SETUP_PER_CPU_AREA)
 116extern void __init setup_per_cpu_areas(void);
 117#endif
 118extern void __init percpu_init_late(void);
 119
 120extern void __percpu *__alloc_percpu_gfp(size_t size, size_t align, gfp_t gfp);
 121extern void __percpu *__alloc_percpu(size_t size, size_t align);
 122extern void free_percpu(void __percpu *__pdata);
 123extern phys_addr_t per_cpu_ptr_to_phys(void *addr);
 124
 125#define alloc_percpu_gfp(type, gfp)                                     \
 126        (typeof(type) __percpu *)__alloc_percpu_gfp(sizeof(type),       \
 127                                                __alignof__(type), gfp)
 128#define alloc_percpu(type)                                              \
 129        (typeof(type) __percpu *)__alloc_percpu(sizeof(type),           \
 130                                                __alignof__(type))
 131
 132/* To avoid include hell, as printk can not declare this, we declare it here */
 133DECLARE_PER_CPU(printk_func_t, printk_func);
 134
 135#endif /* __LINUX_PERCPU_H */
 136