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 #include <linux/cleanup.h> 12 13 #include <asm/percpu.h> 14 15 /* enough to cover all DEFINE_PER_CPUs in modules */ 16 #ifdef CONFIG_MODULES 17 #define PERCPU_MODULE_RESERVE (8 << 10) 18 #else 19 #define PERCPU_MODULE_RESERVE 0 20 #endif 21 22 /* minimum unit size, also is the maximum supported allocation size */ 23 #define PCPU_MIN_UNIT_SIZE PFN_ALIGN(32 << 10) 24 25 /* minimum allocation size and shift in bytes */ 26 #define PCPU_MIN_ALLOC_SHIFT 2 27 #define PCPU_MIN_ALLOC_SIZE (1 << PCPU_MIN_ALLOC_SHIFT) 28 29 /* 30 * The PCPU_BITMAP_BLOCK_SIZE must be the same size as PAGE_SIZE as the 31 * updating of hints is used to manage the nr_empty_pop_pages in both 32 * the chunk and globally. 33 */ 34 #define PCPU_BITMAP_BLOCK_SIZE PAGE_SIZE 35 #define PCPU_BITMAP_BLOCK_BITS (PCPU_BITMAP_BLOCK_SIZE >> \ 36 PCPU_MIN_ALLOC_SHIFT) 37 38 #ifdef CONFIG_RANDOM_KMALLOC_CACHES 39 #define PERCPU_DYNAMIC_SIZE_SHIFT 12 40 #else 41 #define PERCPU_DYNAMIC_SIZE_SHIFT 10 42 #endif 43 44 /* 45 * Percpu allocator can serve percpu allocations before slab is 46 * initialized which allows slab to depend on the percpu allocator. 47 * The following parameter decide how much resource to preallocate 48 * for this. Keep PERCPU_DYNAMIC_RESERVE equal to or larger than 49 * PERCPU_DYNAMIC_EARLY_SIZE. 50 */ 51 #define PERCPU_DYNAMIC_EARLY_SIZE (20 << PERCPU_DYNAMIC_SIZE_SHIFT) 52 53 /* 54 * PERCPU_DYNAMIC_RESERVE indicates the amount of free area to piggy 55 * back on the first chunk for dynamic percpu allocation if arch is 56 * manually allocating and mapping it for faster access (as a part of 57 * large page mapping for example). 58 * 59 * The following values give between one and two pages of free space 60 * after typical minimal boot (2-way SMP, single disk and NIC) with 61 * both defconfig and a distro config on x86_64 and 32. More 62 * intelligent way to determine this would be nice. 63 */ 64 #if BITS_PER_LONG > 32 65 #define PERCPU_DYNAMIC_RESERVE (28 << PERCPU_DYNAMIC_SIZE_SHIFT) 66 #else 67 #define PERCPU_DYNAMIC_RESERVE (20 << PERCPU_DYNAMIC_SIZE_SHIFT) 68 #endif 69 70 extern void *pcpu_base_addr; 71 extern const unsigned long *pcpu_unit_offsets; 72 73 struct pcpu_group_info { 74 int nr_units; /* aligned # of units */ 75 unsigned long base_offset; /* base address offset */ 76 unsigned int *cpu_map; /* unit->cpu map, empty 77 * entries contain NR_CPUS */ 78 }; 79 80 struct pcpu_alloc_info { 81 size_t static_size; 82 size_t reserved_size; 83 size_t dyn_size; 84 size_t unit_size; 85 size_t atom_size; 86 size_t alloc_size; 87 size_t __ai_size; /* internal, don't use */ 88 int nr_groups; /* 0 if grouping unnecessary */ 89 struct pcpu_group_info groups[]; 90 }; 91 92 enum pcpu_fc { 93 PCPU_FC_AUTO, 94 PCPU_FC_EMBED, 95 PCPU_FC_PAGE, 96 97 PCPU_FC_NR, 98 }; 99 extern const char * const pcpu_fc_names[PCPU_FC_NR]; 100 101 extern enum pcpu_fc pcpu_chosen_fc; 102 103 typedef int (pcpu_fc_cpu_to_node_fn_t)(int cpu); 104 typedef int (pcpu_fc_cpu_distance_fn_t)(unsigned int from, unsigned int to); 105 106 extern struct pcpu_alloc_info * __init pcpu_alloc_alloc_info(int nr_groups, 107 int nr_units); 108 extern void __init pcpu_free_alloc_info(struct pcpu_alloc_info *ai); 109 110 extern void __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai, 111 void *base_addr); 112 113 extern int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size, 114 size_t atom_size, 115 pcpu_fc_cpu_distance_fn_t cpu_distance_fn, 116 pcpu_fc_cpu_to_node_fn_t cpu_to_nd_fn); 117 118 #ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK 119 void __init pcpu_populate_pte(unsigned long addr); 120 extern int __init pcpu_page_first_chunk(size_t reserved_size, 121 pcpu_fc_cpu_to_node_fn_t cpu_to_nd_fn); 122 #endif 123 124 extern void __percpu *__alloc_reserved_percpu(size_t size, size_t align) __alloc_size(1); 125 extern bool __is_kernel_percpu_address(unsigned long addr, unsigned long *can_addr); 126 extern bool is_kernel_percpu_address(unsigned long addr); 127 128 #if !defined(CONFIG_SMP) || !defined(CONFIG_HAVE_SETUP_PER_CPU_AREA) 129 extern void __init setup_per_cpu_areas(void); 130 #endif 131 132 extern void __percpu *__alloc_percpu_gfp(size_t size, size_t align, gfp_t gfp) __alloc_size(1); 133 extern void __percpu *__alloc_percpu(size_t size, size_t align) __alloc_size(1); 134 extern void free_percpu(void __percpu *__pdata); 135 136 DEFINE_FREE(free_percpu, void __percpu *, free_percpu(_T)) 137 138 extern phys_addr_t per_cpu_ptr_to_phys(void *addr); 139 140 #define alloc_percpu_gfp(type, gfp) \ 141 (typeof(type) __percpu *)__alloc_percpu_gfp(sizeof(type), \ 142 __alignof__(type), gfp) 143 #define alloc_percpu(type) \ 144 (typeof(type) __percpu *)__alloc_percpu(sizeof(type), \ 145 __alignof__(type)) 146 147 extern unsigned long pcpu_nr_pages(void); 148 149 #endif /* __LINUX_PERCPU_H */ 150