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