percpu.h 4.7 KB

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  1. /* SPDX-License-Identifier: GPL-2.0 */
  2. #ifndef __LINUX_PERCPU_H
  3. #define __LINUX_PERCPU_H
  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. #include <asm/percpu.h>
  12. /* enough to cover all DEFINE_PER_CPUs in modules */
  13. #ifdef CONFIG_MODULES
  14. #define PERCPU_MODULE_RESERVE (8 << 10)
  15. #else
  16. #define PERCPU_MODULE_RESERVE 0
  17. #endif
  18. /* minimum unit size, also is the maximum supported allocation size */
  19. #define PCPU_MIN_UNIT_SIZE PFN_ALIGN(32 << 10)
  20. /* minimum allocation size and shift in bytes */
  21. #define PCPU_MIN_ALLOC_SHIFT 2
  22. #define PCPU_MIN_ALLOC_SIZE (1 << PCPU_MIN_ALLOC_SHIFT)
  23. /*
  24. * The PCPU_BITMAP_BLOCK_SIZE must be the same size as PAGE_SIZE as the
  25. * updating of hints is used to manage the nr_empty_pop_pages in both
  26. * the chunk and globally.
  27. */
  28. #define PCPU_BITMAP_BLOCK_SIZE PAGE_SIZE
  29. #define PCPU_BITMAP_BLOCK_BITS (PCPU_BITMAP_BLOCK_SIZE >> \
  30. PCPU_MIN_ALLOC_SHIFT)
  31. /*
  32. * Percpu allocator can serve percpu allocations before slab is
  33. * initialized which allows slab to depend on the percpu allocator.
  34. * The following two parameters decide how much resource to
  35. * preallocate for this. Keep PERCPU_DYNAMIC_RESERVE equal to or
  36. * larger than PERCPU_DYNAMIC_EARLY_SIZE.
  37. */
  38. #define PERCPU_DYNAMIC_EARLY_SLOTS 128
  39. #define PERCPU_DYNAMIC_EARLY_SIZE (12 << 10)
  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. extern void *pcpu_base_addr;
  57. extern const unsigned long *pcpu_unit_offsets;
  58. struct pcpu_group_info {
  59. int nr_units; /* aligned # of units */
  60. unsigned long base_offset; /* base address offset */
  61. unsigned int *cpu_map; /* unit->cpu map, empty
  62. * entries contain NR_CPUS */
  63. };
  64. struct pcpu_alloc_info {
  65. size_t static_size;
  66. size_t reserved_size;
  67. size_t dyn_size;
  68. size_t unit_size;
  69. size_t atom_size;
  70. size_t alloc_size;
  71. size_t __ai_size; /* internal, don't use */
  72. int nr_groups; /* 0 if grouping unnecessary */
  73. struct pcpu_group_info groups[];
  74. };
  75. enum pcpu_fc {
  76. PCPU_FC_AUTO,
  77. PCPU_FC_EMBED,
  78. PCPU_FC_PAGE,
  79. PCPU_FC_NR,
  80. };
  81. extern const char * const pcpu_fc_names[PCPU_FC_NR];
  82. extern enum pcpu_fc pcpu_chosen_fc;
  83. typedef void * (*pcpu_fc_alloc_fn_t)(unsigned int cpu, size_t size,
  84. size_t align);
  85. typedef void (*pcpu_fc_free_fn_t)(void *ptr, size_t size);
  86. typedef void (*pcpu_fc_populate_pte_fn_t)(unsigned long addr);
  87. typedef int (pcpu_fc_cpu_distance_fn_t)(unsigned int from, unsigned int to);
  88. extern struct pcpu_alloc_info * __init pcpu_alloc_alloc_info(int nr_groups,
  89. int nr_units);
  90. extern void __init pcpu_free_alloc_info(struct pcpu_alloc_info *ai);
  91. extern void __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
  92. void *base_addr);
  93. #ifdef CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK
  94. extern int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size,
  95. size_t atom_size,
  96. pcpu_fc_cpu_distance_fn_t cpu_distance_fn,
  97. pcpu_fc_alloc_fn_t alloc_fn,
  98. pcpu_fc_free_fn_t free_fn);
  99. #endif
  100. #ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK
  101. extern int __init pcpu_page_first_chunk(size_t reserved_size,
  102. pcpu_fc_alloc_fn_t alloc_fn,
  103. pcpu_fc_free_fn_t free_fn,
  104. pcpu_fc_populate_pte_fn_t populate_pte_fn);
  105. #endif
  106. extern void __percpu *__alloc_reserved_percpu(size_t size, size_t align);
  107. extern bool __is_kernel_percpu_address(unsigned long addr, unsigned long *can_addr);
  108. extern bool is_kernel_percpu_address(unsigned long addr);
  109. #if !defined(CONFIG_SMP) || !defined(CONFIG_HAVE_SETUP_PER_CPU_AREA)
  110. extern void __init setup_per_cpu_areas(void);
  111. #endif
  112. extern void __percpu *__alloc_percpu_gfp(size_t size, size_t align, gfp_t gfp);
  113. extern void __percpu *__alloc_percpu(size_t size, size_t align);
  114. extern void free_percpu(void __percpu *__pdata);
  115. extern phys_addr_t per_cpu_ptr_to_phys(void *addr);
  116. #define alloc_percpu_gfp(type, gfp) \
  117. (typeof(type) __percpu *)__alloc_percpu_gfp(sizeof(type), \
  118. __alignof__(type), gfp)
  119. #define alloc_percpu(type) \
  120. (typeof(type) __percpu *)__alloc_percpu(sizeof(type), \
  121. __alignof__(type))
  122. extern unsigned long pcpu_nr_pages(void);
  123. #endif /* __LINUX_PERCPU_H */