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
  51 extern void *pcpu_base_addr;
  52 extern const unsigned long *pcpu_unit_offsets;
  53
  54 struct 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
  61 struct 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
  73 enum pcpu_fc {
  74         PCPU_FC_AUTO,
  75         PCPU_FC_EMBED,
  76         PCPU_FC_PAGE,
  77
  78         PCPU_FC_NR,
  79 };
  80 extern const char * const pcpu_fc_names[PCPU_FC_NR];
  81
  82 extern enum pcpu_fc pcpu_chosen_fc;
  83
  84 typedef void * (*pcpu_fc_alloc_fn_t)(unsigned int cpu, size_t size,
  85                                      size_t align);
  86 typedef void (*pcpu_fc_free_fn_t)(void *ptr, size_t size);
  87 typedef void (*pcpu_fc_populate_pte_fn_t)(unsigned long addr);
  88 typedef int (pcpu_fc_cpu_distance_fn_t)(unsigned int from, unsigned int to);
  89
  90 extern struct pcpu_alloc_info * __init pcpu_alloc_alloc_info(int nr_groups,
  91                                                              int nr_units);
  92 extern void __init pcpu_free_alloc_info(struct pcpu_alloc_info *ai);
  93
  94 extern 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
  98 extern 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
 106 extern 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
 112 extern void __percpu *__alloc_reserved_percpu(size_t size, size_t align);
 113 extern bool __is_kernel_percpu_address(unsigned long addr, unsigned long *can_addr);
 114 extern bool is_kernel_percpu_address(unsigned long addr);
 115
 116 #if !defined(CONFIG_SMP) || !defined(CONFIG_HAVE_SETUP_PER_CPU_AREA)
 117 extern void __init setup_per_cpu_areas(void);
 118 #endif
 119 extern void __init percpu_init_late(void);
 120
 121 extern void __percpu *__alloc_percpu_gfp(size_t size, size_t align, gfp_t gfp);
 122 extern void __percpu *__alloc_percpu(size_t size, size_t align);
 123 extern void free_percpu(void __percpu *__pdata);
 124 extern phys_addr_t per_cpu_ptr_to_phys(void *addr);
 125
 126 #define alloc_percpu_gfp(type, gfp)                                     \
 127         (typeof(type) __percpu *)__alloc_percpu_gfp(sizeof(type),       \
 128                                                 __alignof__(type), gfp)
 129 #define alloc_percpu(type)                                              \
 130         (typeof(type) __percpu *)__alloc_percpu(sizeof(type),           \
 131                                                 __alignof__(type))
 132
 133 #endif /* __LINUX_PERCPU_H */