1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __LINUX_PERCPU_H
3 #define __LINUX_PERCPU_H
5 #include <linux/mmdebug.h>
6 #include <linux/preempt.h>
8 #include <linux/cpumask.h>
10 #include <linux/init.h>
11 #include <linux/cleanup.h>
13 #include <asm/percpu.h>
15 /* enough to cover all DEFINE_PER_CPUs in modules */
17 #define PERCPU_MODULE_RESERVE (8 << 10)
19 #define PERCPU_MODULE_RESERVE 0
22 /* minimum unit size, also is the maximum supported allocation size */
23 #define PCPU_MIN_UNIT_SIZE PFN_ALIGN(32 << 10)
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)
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.
34 #define PCPU_BITMAP_BLOCK_SIZE PAGE_SIZE
35 #define PCPU_BITMAP_BLOCK_BITS (PCPU_BITMAP_BLOCK_SIZE >> \
38 #ifdef CONFIG_RANDOM_KMALLOC_CACHES
39 #define PERCPU_DYNAMIC_SIZE_SHIFT 12
41 #define PERCPU_DYNAMIC_SIZE_SHIFT 10
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.
51 #define PERCPU_DYNAMIC_EARLY_SIZE (20 << PERCPU_DYNAMIC_SIZE_SHIFT)
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).
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.
64 #if BITS_PER_LONG > 32
65 #define PERCPU_DYNAMIC_RESERVE (28 << PERCPU_DYNAMIC_SIZE_SHIFT)
67 #define PERCPU_DYNAMIC_RESERVE (20 << PERCPU_DYNAMIC_SIZE_SHIFT)
70 extern void *pcpu_base_addr;
71 extern const unsigned long *pcpu_unit_offsets;
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 */
80 struct pcpu_alloc_info {
87 size_t __ai_size; /* internal, don't use */
88 int nr_groups; /* 0 if grouping unnecessary */
89 struct pcpu_group_info groups[];
99 extern const char * const pcpu_fc_names[PCPU_FC_NR];
101 extern enum pcpu_fc pcpu_chosen_fc;
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);
106 extern struct pcpu_alloc_info * __init pcpu_alloc_alloc_info(int nr_groups,
108 extern void __init pcpu_free_alloc_info(struct pcpu_alloc_info *ai);
110 extern void __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
113 extern int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size,
115 pcpu_fc_cpu_distance_fn_t cpu_distance_fn,
116 pcpu_fc_cpu_to_node_fn_t cpu_to_nd_fn);
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);
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);
128 #if !defined(CONFIG_SMP) || !defined(CONFIG_HAVE_SETUP_PER_CPU_AREA)
129 extern void __init setup_per_cpu_areas(void);
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 extern size_t pcpu_alloc_size(void __percpu *__pdata);
137 DEFINE_FREE(free_percpu, void __percpu *, free_percpu(_T))
139 extern phys_addr_t per_cpu_ptr_to_phys(void *addr);
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), \
148 extern unsigned long pcpu_nr_pages(void);
150 #endif /* __LINUX_PERCPU_H */