1 #ifndef __LINUX_PERCPU_H 2 #define __LINUX_PERCPU_H 3 4 #include <linux/mmdebug.h> 5 #include <linux/preempt.h> 6 #include <linux/smp.h> 7 #include <linux/cpumask.h> 8 #include <linux/printk.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 * This determines the size of each metadata block. There are several subtle 30 * constraints around this constant. The reserved region must be a multiple of 31 * PCPU_BITMAP_BLOCK_SIZE. Additionally, PCPU_BITMAP_BLOCK_SIZE must be a 32 * multiple of PAGE_SIZE or PAGE_SIZE must be a multiple of 33 * PCPU_BITMAP_BLOCK_SIZE to align with the populated page map. The unit_size 34 * also has to be a multiple of PCPU_BITMAP_BLOCK_SIZE to ensure full blocks. 35 */ 36 #define PCPU_BITMAP_BLOCK_SIZE PAGE_SIZE 37 #define PCPU_BITMAP_BLOCK_BITS (PCPU_BITMAP_BLOCK_SIZE >> \ 38 PCPU_MIN_ALLOC_SHIFT) 39 40 /* 41 * Percpu allocator can serve percpu allocations before slab is 42 * initialized which allows slab to depend on the percpu allocator. 43 * The following two parameters decide how much resource to 44 * preallocate for this. Keep PERCPU_DYNAMIC_RESERVE equal to or 45 * larger than PERCPU_DYNAMIC_EARLY_SIZE. 46 */ 47 #define PERCPU_DYNAMIC_EARLY_SLOTS 128 48 #define PERCPU_DYNAMIC_EARLY_SIZE (12 << 10) 49 50 /* 51 * PERCPU_DYNAMIC_RESERVE indicates the amount of free area to piggy 52 * back on the first chunk for dynamic percpu allocation if arch is 53 * manually allocating and mapping it for faster access (as a part of 54 * large page mapping for example). 55 * 56 * The following values give between one and two pages of free space 57 * after typical minimal boot (2-way SMP, single disk and NIC) with 58 * both defconfig and a distro config on x86_64 and 32. More 59 * intelligent way to determine this would be nice. 60 */ 61 #if BITS_PER_LONG > 32 62 #define PERCPU_DYNAMIC_RESERVE (28 << 10) 63 #else 64 #define PERCPU_DYNAMIC_RESERVE (20 << 10) 65 #endif 66 67 extern void *pcpu_base_addr; 68 extern const unsigned long *pcpu_unit_offsets; 69 70 struct pcpu_group_info { 71 int nr_units; /* aligned # of units */ 72 unsigned long base_offset; /* base address offset */ 73 unsigned int *cpu_map; /* unit->cpu map, empty 74 * entries contain NR_CPUS */ 75 }; 76 77 struct pcpu_alloc_info { 78 size_t static_size; 79 size_t reserved_size; 80 size_t dyn_size; 81 size_t unit_size; 82 size_t atom_size; 83 size_t alloc_size; 84 size_t __ai_size; /* internal, don't use */ 85 int nr_groups; /* 0 if grouping unnecessary */ 86 struct pcpu_group_info groups[]; 87 }; 88 89 enum pcpu_fc { 90 PCPU_FC_AUTO, 91 PCPU_FC_EMBED, 92 PCPU_FC_PAGE, 93 94 PCPU_FC_NR, 95 }; 96 extern const char * const pcpu_fc_names[PCPU_FC_NR]; 97 98 extern enum pcpu_fc pcpu_chosen_fc; 99 100 typedef void * (*pcpu_fc_alloc_fn_t)(unsigned int cpu, size_t size, 101 size_t align); 102 typedef void (*pcpu_fc_free_fn_t)(void *ptr, size_t size); 103 typedef void (*pcpu_fc_populate_pte_fn_t)(unsigned long addr); 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 int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai, 111 void *base_addr); 112 113 #ifdef CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK 114 extern int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size, 115 size_t atom_size, 116 pcpu_fc_cpu_distance_fn_t cpu_distance_fn, 117 pcpu_fc_alloc_fn_t alloc_fn, 118 pcpu_fc_free_fn_t free_fn); 119 #endif 120 121 #ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK 122 extern int __init pcpu_page_first_chunk(size_t reserved_size, 123 pcpu_fc_alloc_fn_t alloc_fn, 124 pcpu_fc_free_fn_t free_fn, 125 pcpu_fc_populate_pte_fn_t populate_pte_fn); 126 #endif 127 128 extern void __percpu *__alloc_reserved_percpu(size_t size, size_t align); 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); 137 extern void __percpu *__alloc_percpu(size_t size, size_t align); 138 extern void free_percpu(void __percpu *__pdata); 139 extern phys_addr_t per_cpu_ptr_to_phys(void *addr); 140 141 #define alloc_percpu_gfp(type, gfp) \ 142 (typeof(type) __percpu *)__alloc_percpu_gfp(sizeof(type), \ 143 __alignof__(type), gfp) 144 #define alloc_percpu(type) \ 145 (typeof(type) __percpu *)__alloc_percpu(sizeof(type), \ 146 __alignof__(type)) 147 148 #endif /* __LINUX_PERCPU_H */ 149