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
  57 extern void *pcpu_base_addr;
  58 extern const unsigned long *pcpu_unit_offsets;
  59
  60 struct 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
  67 struct 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
  79 enum pcpu_fc {
  80         PCPU_FC_AUTO,
  81         PCPU_FC_EMBED,
  82         PCPU_FC_PAGE,
  83
  84         PCPU_FC_NR,
  85 };
  86 extern const char * const pcpu_fc_names[PCPU_FC_NR];
  87
  88 extern enum pcpu_fc pcpu_chosen_fc;
  89
  90 typedef void * (*pcpu_fc_alloc_fn_t)(unsigned int cpu, size_t size,
  91                                      size_t align);
  92 typedef void (*pcpu_fc_free_fn_t)(void *ptr, size_t size);
  93 typedef void (*pcpu_fc_populate_pte_fn_t)(unsigned long addr);
  94 typedef int (pcpu_fc_cpu_distance_fn_t)(unsigned int from, unsigned int to);
  95
  96 extern struct pcpu_alloc_info * __init pcpu_alloc_alloc_info(int nr_groups,
  97                                                              int nr_units);
  98 extern void __init pcpu_free_alloc_info(struct pcpu_alloc_info *ai);
  99
 100 extern 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
 104 extern 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
 112 extern 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
 118 extern void __percpu *__alloc_reserved_percpu(size_t size, size_t align);
 119 extern bool is_kernel_percpu_address(unsigned long addr);
 120
 121 #if !defined(CONFIG_SMP) || !defined(CONFIG_HAVE_SETUP_PER_CPU_AREA)
 122 extern void __init setup_per_cpu_areas(void);
 123 #endif
 124 extern void __init percpu_init_late(void);
 125
 126 extern void __percpu *__alloc_percpu_gfp(size_t size, size_t align, gfp_t gfp);
 127 extern void __percpu *__alloc_percpu(size_t size, size_t align);
 128 extern void free_percpu(void __percpu *__pdata);
 129 extern 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 */
 139 DECLARE_PER_CPU(printk_func_t, printk_func);
 140
 141 #endif /* __LINUX_PERCPU_H */