percpu.h (4581B)
1/* SPDX-License-Identifier: GPL-2.0 */ 2#ifndef __LINUX_PERCPU_H 3#define __LINUX_PERCPU_H 4 5#include <linux/mmdebug.h> 6#include <linux/preempt.h> 7#include <linux/smp.h> 8#include <linux/cpumask.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/* minimum allocation size and shift in bytes */ 25#define PCPU_MIN_ALLOC_SHIFT 2 26#define PCPU_MIN_ALLOC_SIZE (1 << PCPU_MIN_ALLOC_SHIFT) 27 28/* 29 * The PCPU_BITMAP_BLOCK_SIZE must be the same size as PAGE_SIZE as the 30 * updating of hints is used to manage the nr_empty_pop_pages in both 31 * the chunk and globally. 32 */ 33#define PCPU_BITMAP_BLOCK_SIZE PAGE_SIZE 34#define PCPU_BITMAP_BLOCK_BITS (PCPU_BITMAP_BLOCK_SIZE >> \ 35 PCPU_MIN_ALLOC_SHIFT) 36 37/* 38 * Percpu allocator can serve percpu allocations before slab is 39 * initialized which allows slab to depend on the percpu allocator. 40 * The following two parameters decide how much resource to 41 * preallocate for this. Keep PERCPU_DYNAMIC_RESERVE equal to or 42 * larger than PERCPU_DYNAMIC_EARLY_SIZE. 43 */ 44#define PERCPU_DYNAMIC_EARLY_SLOTS 128 45#define PERCPU_DYNAMIC_EARLY_SIZE (12 << 10) 46 47/* 48 * PERCPU_DYNAMIC_RESERVE indicates the amount of free area to piggy 49 * back on the first chunk for dynamic percpu allocation if arch is 50 * manually allocating and mapping it for faster access (as a part of 51 * large page mapping for example). 52 * 53 * The following values give between one and two pages of free space 54 * after typical minimal boot (2-way SMP, single disk and NIC) with 55 * both defconfig and a distro config on x86_64 and 32. More 56 * intelligent way to determine this would be nice. 57 */ 58#if BITS_PER_LONG > 32 59#define PERCPU_DYNAMIC_RESERVE (28 << 10) 60#else 61#define PERCPU_DYNAMIC_RESERVE (20 << 10) 62#endif 63 64extern void *pcpu_base_addr; 65extern const unsigned long *pcpu_unit_offsets; 66 67struct pcpu_group_info { 68 int nr_units; /* aligned # of units */ 69 unsigned long base_offset; /* base address offset */ 70 unsigned int *cpu_map; /* unit->cpu map, empty 71 * entries contain NR_CPUS */ 72}; 73 74struct pcpu_alloc_info { 75 size_t static_size; 76 size_t reserved_size; 77 size_t dyn_size; 78 size_t unit_size; 79 size_t atom_size; 80 size_t alloc_size; 81 size_t __ai_size; /* internal, don't use */ 82 int nr_groups; /* 0 if grouping unnecessary */ 83 struct pcpu_group_info groups[]; 84}; 85 86enum pcpu_fc { 87 PCPU_FC_AUTO, 88 PCPU_FC_EMBED, 89 PCPU_FC_PAGE, 90 91 PCPU_FC_NR, 92}; 93extern const char * const pcpu_fc_names[PCPU_FC_NR]; 94 95extern enum pcpu_fc pcpu_chosen_fc; 96 97typedef int (pcpu_fc_cpu_to_node_fn_t)(int cpu); 98typedef int (pcpu_fc_cpu_distance_fn_t)(unsigned int from, unsigned int to); 99 100extern struct pcpu_alloc_info * __init pcpu_alloc_alloc_info(int nr_groups, 101 int nr_units); 102extern void __init pcpu_free_alloc_info(struct pcpu_alloc_info *ai); 103 104extern void __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai, 105 void *base_addr); 106 107#ifdef CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK 108extern int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size, 109 size_t atom_size, 110 pcpu_fc_cpu_distance_fn_t cpu_distance_fn, 111 pcpu_fc_cpu_to_node_fn_t cpu_to_nd_fn); 112#endif 113 114#ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK 115void __init pcpu_populate_pte(unsigned long addr); 116extern int __init pcpu_page_first_chunk(size_t reserved_size, 117 pcpu_fc_cpu_to_node_fn_t cpu_to_nd_fn); 118#endif 119 120extern void __percpu *__alloc_reserved_percpu(size_t size, size_t align) __alloc_size(1); 121extern bool __is_kernel_percpu_address(unsigned long addr, unsigned long *can_addr); 122extern bool is_kernel_percpu_address(unsigned long addr); 123 124#if !defined(CONFIG_SMP) || !defined(CONFIG_HAVE_SETUP_PER_CPU_AREA) 125extern void __init setup_per_cpu_areas(void); 126#endif 127 128extern void __percpu *__alloc_percpu_gfp(size_t size, size_t align, gfp_t gfp) __alloc_size(1); 129extern void __percpu *__alloc_percpu(size_t size, size_t align) __alloc_size(1); 130extern void free_percpu(void __percpu *__pdata); 131extern phys_addr_t per_cpu_ptr_to_phys(void *addr); 132 133#define alloc_percpu_gfp(type, gfp) \ 134 (typeof(type) __percpu *)__alloc_percpu_gfp(sizeof(type), \ 135 __alignof__(type), gfp) 136#define alloc_percpu(type) \ 137 (typeof(type) __percpu *)__alloc_percpu(sizeof(type), \ 138 __alignof__(type)) 139 140extern unsigned long pcpu_nr_pages(void); 141 142#endif /* __LINUX_PERCPU_H */