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 #ifdef CONFIG_MEM_ALLOC_PROFILING 18 #define PERCPU_MODULE_RESERVE (8 << 13) 19 #else 20 #define PERCPU_MODULE_RESERVE (8 << 10) 21 #endif 22 #else 23 #define PERCPU_MODULE_RESERVE 0 24 #endif 25 26 /* minimum unit size, also is the maximum supported allocation size */ 27 #define PCPU_MIN_UNIT_SIZE PFN_ALIGN(32 << 10) 28 29 /* minimum allocation size and shift in bytes */ 30 #define PCPU_MIN_ALLOC_SHIFT 2 31 #define PCPU_MIN_ALLOC_SIZE (1 << PCPU_MIN_ALLOC_SHIFT) 32 33 /* 34 * The PCPU_BITMAP_BLOCK_SIZE must be the same size as PAGE_SIZE as the 35 * updating of hints is used to manage the nr_empty_pop_pages in both 36 * the chunk and globally. 37 */ 38 #define PCPU_BITMAP_BLOCK_SIZE PAGE_SIZE 39 #define PCPU_BITMAP_BLOCK_BITS (PCPU_BITMAP_BLOCK_SIZE >> \ 40 PCPU_MIN_ALLOC_SHIFT) 41 42 #ifdef CONFIG_RANDOM_KMALLOC_CACHES 43 #define PERCPU_DYNAMIC_SIZE_SHIFT 12 44 #else 45 #define PERCPU_DYNAMIC_SIZE_SHIFT 10 46 #endif 47 48 /* 49 * Percpu allocator can serve percpu allocations before slab is 50 * initialized which allows slab to depend on the percpu allocator. 51 * The following parameter decide how much resource to preallocate 52 * for this. Keep PERCPU_DYNAMIC_RESERVE equal to or larger than 53 * PERCPU_DYNAMIC_EARLY_SIZE. 54 */ 55 #define PERCPU_DYNAMIC_EARLY_SIZE (20 << PERCPU_DYNAMIC_SIZE_SHIFT) 56 57 /* 58 * PERCPU_DYNAMIC_RESERVE indicates the amount of free area to piggy 59 * back on the first chunk for dynamic percpu allocation if arch is 60 * manually allocating and mapping it for faster access (as a part of 61 * large page mapping for example). 62 * 63 * The following values give between one and two pages of free space 64 * after typical minimal boot (2-way SMP, single disk and NIC) with 65 * both defconfig and a distro config on x86_64 and 32. More 66 * intelligent way to determine this would be nice. 67 */ 68 #if BITS_PER_LONG > 32 69 #define PERCPU_DYNAMIC_RESERVE (28 << PERCPU_DYNAMIC_SIZE_SHIFT) 70 #else 71 #define PERCPU_DYNAMIC_RESERVE (20 << PERCPU_DYNAMIC_SIZE_SHIFT) 72 #endif 73 74 extern void *pcpu_base_addr; 75 extern const unsigned long *pcpu_unit_offsets; 76 77 struct pcpu_group_info { 78 int nr_units; /* aligned # of units */ 79 unsigned long base_offset; /* base address offset */ 80 unsigned int *cpu_map; /* unit->cpu map, empty 81 * entries contain NR_CPUS */ 82 }; 83 84 struct pcpu_alloc_info { 85 size_t static_size; 86 size_t reserved_size; 87 size_t dyn_size; 88 size_t unit_size; 89 size_t atom_size; 90 size_t alloc_size; 91 size_t __ai_size; /* internal, don't use */ 92 int nr_groups; /* 0 if grouping unnecessary */ 93 struct pcpu_group_info groups[]; 94 }; 95 96 enum pcpu_fc { 97 PCPU_FC_AUTO, 98 PCPU_FC_EMBED, 99 PCPU_FC_PAGE, 100 101 PCPU_FC_NR, 102 }; 103 extern const char * const pcpu_fc_names[PCPU_FC_NR]; 104 105 extern enum pcpu_fc pcpu_chosen_fc; 106 107 typedef int (pcpu_fc_cpu_to_node_fn_t)(int cpu); 108 typedef int (pcpu_fc_cpu_distance_fn_t)(unsigned int from, unsigned int to); 109 110 extern struct pcpu_alloc_info * __init pcpu_alloc_alloc_info(int nr_groups, 111 int nr_units); 112 extern void __init pcpu_free_alloc_info(struct pcpu_alloc_info *ai); 113 114 extern void __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai, 115 void *base_addr); 116 117 extern int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size, 118 size_t atom_size, 119 pcpu_fc_cpu_distance_fn_t cpu_distance_fn, 120 pcpu_fc_cpu_to_node_fn_t cpu_to_nd_fn); 121 122 #ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK 123 void __init pcpu_populate_pte(unsigned long addr); 124 extern int __init pcpu_page_first_chunk(size_t reserved_size, 125 pcpu_fc_cpu_to_node_fn_t cpu_to_nd_fn); 126 #endif 127 128 extern void __percpu *__alloc_reserved_percpu(size_t size, size_t align) __alloc_size(1); 129 extern bool __is_kernel_percpu_address(unsigned long addr, unsigned long *can_addr); 130 extern bool is_kernel_percpu_address(unsigned long addr); 131 132 #if !defined(CONFIG_SMP) || !defined(CONFIG_HAVE_SETUP_PER_CPU_AREA) 133 extern void __init setup_per_cpu_areas(void); 134 #endif 135 136 extern void __percpu *__alloc_percpu_gfp(size_t size, size_t align, gfp_t gfp) __alloc_size(1); 137 extern void __percpu *__alloc_percpu(size_t size, size_t align) __alloc_size(1); 138 extern void free_percpu(void __percpu *__pdata); 139 extern size_t pcpu_alloc_size(void __percpu *__pdata); 140 141 DEFINE_FREE(free_percpu, void __percpu *, free_percpu(_T)) 142 143 extern phys_addr_t per_cpu_ptr_to_phys(void *addr); 144 145 #define alloc_percpu_gfp(type, gfp) \ 146 (typeof(type) __percpu *)__alloc_percpu_gfp(sizeof(type), \ 147 __alignof__(type), gfp) 148 #define alloc_percpu(type) \ 149 (typeof(type) __percpu *)__alloc_percpu(sizeof(type), \ 150 __alignof__(type)) 151 152 extern unsigned long pcpu_nr_pages(void); 153 154 #endif /* __LINUX_PERCPU_H */ 155