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#ifndef PERCPU_ENOUGH_ROOM
  22#define PERCPU_ENOUGH_ROOM                                              \
  23        (ALIGN(__per_cpu_end - __per_cpu_start, SMP_CACHE_BYTES) +      \
  24         PERCPU_MODULE_RESERVE)
  25#endif
  26
  27/* minimum unit size, also is the maximum supported allocation size */
  28#define PCPU_MIN_UNIT_SIZE              PFN_ALIGN(32 << 10)
  29
  30/*
  31 * Percpu allocator can serve percpu allocations before slab is
  32 * initialized which allows slab to depend on the percpu allocator.
  33 * The following two parameters decide how much resource to
  34 * preallocate for this.  Keep PERCPU_DYNAMIC_RESERVE equal to or
  35 * larger than PERCPU_DYNAMIC_EARLY_SIZE.
  36 */
  37#define PERCPU_DYNAMIC_EARLY_SLOTS      128
  38#define PERCPU_DYNAMIC_EARLY_SIZE       (12 << 10)
  39
  40/*
  41 * PERCPU_DYNAMIC_RESERVE indicates the amount of free area to piggy
  42 * back on the first chunk for dynamic percpu allocation if arch is
  43 * manually allocating and mapping it for faster access (as a part of
  44 * large page mapping for example).
  45 *
  46 * The following values give between one and two pages of free space
  47 * after typical minimal boot (2-way SMP, single disk and NIC) with
  48 * both defconfig and a distro config on x86_64 and 32.  More
  49 * intelligent way to determine this would be nice.
  50 */
  51#if BITS_PER_LONG > 32
  52#define PERCPU_DYNAMIC_RESERVE          (28 << 10)
  53#else
  54#define PERCPU_DYNAMIC_RESERVE          (20 << 10)
  55#endif
  56
  57extern void *pcpu_base_addr;
  58extern const unsigned long *pcpu_unit_offsets;
  59
  60struct pcpu_group_info {
  61        int                     nr_units;       /* aligned # of units */
  62        unsigned long           base_offset;    /* base address offset */
  63        unsigned int            *cpu_map;       /* unit->cpu map, empty
  64                                                 * entries contain NR_CPUS */
  65};
  66
  67struct pcpu_alloc_info {
  68        size_t                  static_size;
  69        size_t                  reserved_size;
  70        size_t                  dyn_size;
  71        size_t                  unit_size;
  72        size_t                  atom_size;
  73        size_t                  alloc_size;
  74        size_t                  __ai_size;      /* internal, don't use */
  75        int                     nr_groups;      /* 0 if grouping unnecessary */
  76        struct pcpu_group_info  groups[];
  77};
  78
  79enum pcpu_fc {
  80        PCPU_FC_AUTO,
  81        PCPU_FC_EMBED,
  82        PCPU_FC_PAGE,
  83
  84        PCPU_FC_NR,
  85};
  86extern const char * const pcpu_fc_names[PCPU_FC_NR];
  87
  88extern enum pcpu_fc pcpu_chosen_fc;
  89
  90typedef void * (*pcpu_fc_alloc_fn_t)(unsigned int cpu, size_t size,
  91                                     size_t align);
  92typedef void (*pcpu_fc_free_fn_t)(void *ptr, size_t size);
  93typedef void (*pcpu_fc_populate_pte_fn_t)(unsigned long addr);
  94typedef int (pcpu_fc_cpu_distance_fn_t)(unsigned int from, unsigned int to);
  95
  96extern struct pcpu_alloc_info * __init pcpu_alloc_alloc_info(int nr_groups,
  97                                                             int nr_units);
  98extern void __init pcpu_free_alloc_info(struct pcpu_alloc_info *ai);
  99
 100extern int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
 101                                         void *base_addr);
 102
 103#ifdef CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK
 104extern int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size,
 105                                size_t atom_size,
 106                                pcpu_fc_cpu_distance_fn_t cpu_distance_fn,
 107                                pcpu_fc_alloc_fn_t alloc_fn,
 108                                pcpu_fc_free_fn_t free_fn);
 109#endif
 110
 111#ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK
 112extern int __init pcpu_page_first_chunk(size_t reserved_size,
 113                                pcpu_fc_alloc_fn_t alloc_fn,
 114                                pcpu_fc_free_fn_t free_fn,
 115                                pcpu_fc_populate_pte_fn_t populate_pte_fn);
 116#endif
 117
 118extern void __percpu *__alloc_reserved_percpu(size_t size, size_t align);
 119extern bool is_kernel_percpu_address(unsigned long addr);
 120
 121#if !defined(CONFIG_SMP) || !defined(CONFIG_HAVE_SETUP_PER_CPU_AREA)
 122extern void __init setup_per_cpu_areas(void);
 123#endif
 124extern void __init percpu_init_late(void);
 125
 126extern void __percpu *__alloc_percpu_gfp(size_t size, size_t align, gfp_t gfp);
 127extern void __percpu *__alloc_percpu(size_t size, size_t align);
 128extern void free_percpu(void __percpu *__pdata);
 129extern phys_addr_t per_cpu_ptr_to_phys(void *addr);
 130
 131#define alloc_percpu_gfp(type, gfp)                                     \
 132        (typeof(type) __percpu *)__alloc_percpu_gfp(sizeof(type),       \
 133                                                __alignof__(type), gfp)
 134#define alloc_percpu(type)                                              \
 135        (typeof(type) __percpu *)__alloc_percpu(sizeof(type),           \
 136                                                __alignof__(type))
 137
 138/* To avoid include hell, as printk can not declare this, we declare it here */
 139DECLARE_PER_CPU(printk_func_t, printk_func);
 140
 141#endif /* __LINUX_PERCPU_H */
 142