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/printk.h> 10 #include <linux/pfn.h> 11 #include <linux/init.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 /* 39 * Percpu allocator can serve percpu allocations before slab is 40 * initialized which allows slab to depend on the percpu allocator. 41 * The following two parameters decide how much resource to 42 * preallocate for this. Keep PERCPU_DYNAMIC_RESERVE equal to or 43 * larger than PERCPU_DYNAMIC_EARLY_SIZE. 44 */ 45 #define PERCPU_DYNAMIC_EARLY_SLOTS 128 46 #define PERCPU_DYNAMIC_EARLY_SIZE (12 << 10) 47 48 /* 49 * PERCPU_DYNAMIC_RESERVE indicates the amount of free area to piggy 50 * back on the first chunk for dynamic percpu allocation if arch is 51 * manually allocating and mapping it for faster access (as a part of 52 * large page mapping for example). 53 * 54 * The following values give between one and two pages of free space 55 * after typical minimal boot (2-way SMP, single disk and NIC) with 56 * both defconfig and a distro config on x86_64 and 32. More 57 * intelligent way to determine this would be nice. 58 */ 59 #if BITS_PER_LONG > 32 60 #define PERCPU_DYNAMIC_RESERVE (28 << 10) 61 #else 62 #define PERCPU_DYNAMIC_RESERVE (20 << 10) 63 #endif 64 65 extern void *pcpu_base_addr; 66 extern const unsigned long *pcpu_unit_offsets; 67 68 struct pcpu_group_info { 69 int nr_units; /* aligned # of units */ 70 unsigned long base_offset; /* base address offset */ 71 unsigned int *cpu_map; /* unit->cpu map, empty 72 * entries contain NR_CPUS */ 73 }; 74 75 struct pcpu_alloc_info { 76 size_t static_size; 77 size_t reserved_size; 78 size_t dyn_size; 79 size_t unit_size; 80 size_t atom_size; 81 size_t alloc_size; 82 size_t __ai_size; /* internal, don't use */ 83 int nr_groups; /* 0 if grouping unnecessary */ 84 struct pcpu_group_info groups[]; 85 }; 86 87 enum pcpu_fc { 88 PCPU_FC_AUTO, 89 PCPU_FC_EMBED, 90 PCPU_FC_PAGE, 91 92 PCPU_FC_NR, 93 }; 94 extern const char * const pcpu_fc_names[PCPU_FC_NR]; 95 96 extern enum pcpu_fc pcpu_chosen_fc; 97 98 typedef void * (*pcpu_fc_alloc_fn_t)(unsigned int cpu, size_t size, 99 size_t align); 100 typedef void (*pcpu_fc_free_fn_t)(void *ptr, size_t size); 101 typedef void (*pcpu_fc_populate_pte_fn_t)(unsigned long addr); 102 typedef int (pcpu_fc_cpu_distance_fn_t)(unsigned int from, unsigned int to); 103 104 extern struct pcpu_alloc_info * __init pcpu_alloc_alloc_info(int nr_groups, 105 int nr_units); 106 extern void __init pcpu_free_alloc_info(struct pcpu_alloc_info *ai); 107 108 extern int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai, 109 void *base_addr); 110 111 #ifdef CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK 112 extern int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size, 113 size_t atom_size, 114 pcpu_fc_cpu_distance_fn_t cpu_distance_fn, 115 pcpu_fc_alloc_fn_t alloc_fn, 116 pcpu_fc_free_fn_t free_fn); 117 #endif 118 119 #ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK 120 extern int __init pcpu_page_first_chunk(size_t reserved_size, 121 pcpu_fc_alloc_fn_t alloc_fn, 122 pcpu_fc_free_fn_t free_fn, 123 pcpu_fc_populate_pte_fn_t populate_pte_fn); 124 #endif 125 126 extern void __percpu *__alloc_reserved_percpu(size_t size, size_t align); 127 extern bool __is_kernel_percpu_address(unsigned long addr, unsigned long *can_addr); 128 extern bool is_kernel_percpu_address(unsigned long addr); 129 130 #if !defined(CONFIG_SMP) || !defined(CONFIG_HAVE_SETUP_PER_CPU_AREA) 131 extern void __init setup_per_cpu_areas(void); 132 #endif 133 134 extern void __percpu *__alloc_percpu_gfp(size_t size, size_t align, gfp_t gfp); 135 extern void __percpu *__alloc_percpu(size_t size, size_t align); 136 extern void free_percpu(void __percpu *__pdata); 137 extern phys_addr_t per_cpu_ptr_to_phys(void *addr); 138 139 #define alloc_percpu_gfp(type, gfp) \ 140 (typeof(type) __percpu *)__alloc_percpu_gfp(sizeof(type), \ 141 __alignof__(type), gfp) 142 #define alloc_percpu(type) \ 143 (typeof(type) __percpu *)__alloc_percpu(sizeof(type), \ 144 __alignof__(type)) 145 146 extern unsigned long pcpu_nr_pages(void); 147 148 #endif /* __LINUX_PERCPU_H */ 149