1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __LINUX_PERCPU_H
3 #define __LINUX_PERCPU_H
5 #include <linux/alloc_tag.h>
6 #include <linux/mmdebug.h>
7 #include <linux/preempt.h>
9 #include <linux/cpumask.h>
10 #include <linux/pfn.h>
11 #include <linux/init.h>
12 #include <linux/cleanup.h>
13 #include <linux/sched.h>
15 #include <asm/percpu.h>
17 /* enough to cover all DEFINE_PER_CPUs in modules */
19 #ifdef CONFIG_MEM_ALLOC_PROFILING
20 #define PERCPU_MODULE_RESERVE (8 << 13)
22 #define PERCPU_MODULE_RESERVE (8 << 10)
25 #define PERCPU_MODULE_RESERVE 0
28 /* minimum unit size, also is the maximum supported allocation size */
29 #define PCPU_MIN_UNIT_SIZE PFN_ALIGN(32 << 10)
31 /* minimum allocation size and shift in bytes */
32 #define PCPU_MIN_ALLOC_SHIFT 2
33 #define PCPU_MIN_ALLOC_SIZE (1 << PCPU_MIN_ALLOC_SHIFT)
36 * The PCPU_BITMAP_BLOCK_SIZE must be the same size as PAGE_SIZE as the
37 * updating of hints is used to manage the nr_empty_pop_pages in both
38 * the chunk and globally.
40 #define PCPU_BITMAP_BLOCK_SIZE PAGE_SIZE
41 #define PCPU_BITMAP_BLOCK_BITS (PCPU_BITMAP_BLOCK_SIZE >> \
44 #ifdef CONFIG_RANDOM_KMALLOC_CACHES
45 #define PERCPU_DYNAMIC_SIZE_SHIFT 12
47 #define PERCPU_DYNAMIC_SIZE_SHIFT 10
51 * Percpu allocator can serve percpu allocations before slab is
52 * initialized which allows slab to depend on the percpu allocator.
53 * The following parameter decide how much resource to preallocate
54 * for this. Keep PERCPU_DYNAMIC_RESERVE equal to or larger than
55 * PERCPU_DYNAMIC_EARLY_SIZE.
57 #define PERCPU_DYNAMIC_EARLY_SIZE (20 << PERCPU_DYNAMIC_SIZE_SHIFT)
60 * PERCPU_DYNAMIC_RESERVE indicates the amount of free area to piggy
61 * back on the first chunk for dynamic percpu allocation if arch is
62 * manually allocating and mapping it for faster access (as a part of
63 * large page mapping for example).
65 * The following values give between one and two pages of free space
66 * after typical minimal boot (2-way SMP, single disk and NIC) with
67 * both defconfig and a distro config on x86_64 and 32. More
68 * intelligent way to determine this would be nice.
70 #if BITS_PER_LONG > 32
71 #define PERCPU_DYNAMIC_RESERVE (28 << PERCPU_DYNAMIC_SIZE_SHIFT)
73 #define PERCPU_DYNAMIC_RESERVE (20 << PERCPU_DYNAMIC_SIZE_SHIFT)
76 extern void *pcpu_base_addr;
77 extern const unsigned long *pcpu_unit_offsets;
79 struct pcpu_group_info {
80 int nr_units; /* aligned # of units */
81 unsigned long base_offset; /* base address offset */
82 unsigned int *cpu_map; /* unit->cpu map, empty
83 * entries contain NR_CPUS */
86 struct pcpu_alloc_info {
93 size_t __ai_size; /* internal, don't use */
94 int nr_groups; /* 0 if grouping unnecessary */
95 struct pcpu_group_info groups[];
105 extern const char * const pcpu_fc_names[PCPU_FC_NR];
107 extern enum pcpu_fc pcpu_chosen_fc;
109 typedef int (pcpu_fc_cpu_to_node_fn_t)(int cpu);
110 typedef int (pcpu_fc_cpu_distance_fn_t)(unsigned int from, unsigned int to);
112 extern struct pcpu_alloc_info * __init pcpu_alloc_alloc_info(int nr_groups,
114 extern void __init pcpu_free_alloc_info(struct pcpu_alloc_info *ai);
116 extern void __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
119 extern int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size,
121 pcpu_fc_cpu_distance_fn_t cpu_distance_fn,
122 pcpu_fc_cpu_to_node_fn_t cpu_to_nd_fn);
124 #ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK
125 void __init pcpu_populate_pte(unsigned long addr);
126 extern int __init pcpu_page_first_chunk(size_t reserved_size,
127 pcpu_fc_cpu_to_node_fn_t cpu_to_nd_fn);
130 extern bool __is_kernel_percpu_address(unsigned long addr, unsigned long *can_addr);
131 extern bool is_kernel_percpu_address(unsigned long addr);
133 #if !defined(CONFIG_SMP) || !defined(CONFIG_HAVE_SETUP_PER_CPU_AREA)
134 extern void __init setup_per_cpu_areas(void);
137 extern void __percpu *pcpu_alloc_noprof(size_t size, size_t align, bool reserved,
138 gfp_t gfp) __alloc_size(1);
139 extern size_t pcpu_alloc_size(void __percpu *__pdata);
141 #define __alloc_percpu_gfp(_size, _align, _gfp) \
142 alloc_hooks(pcpu_alloc_noprof(_size, _align, false, _gfp))
143 #define __alloc_percpu(_size, _align) \
144 alloc_hooks(pcpu_alloc_noprof(_size, _align, false, GFP_KERNEL))
145 #define __alloc_reserved_percpu(_size, _align) \
146 alloc_hooks(pcpu_alloc_noprof(_size, _align, true, GFP_KERNEL))
148 #define alloc_percpu_gfp(type, gfp) \
149 (typeof(type) __percpu *)__alloc_percpu_gfp(sizeof(type), \
150 __alignof__(type), gfp)
151 #define alloc_percpu(type) \
152 (typeof(type) __percpu *)__alloc_percpu(sizeof(type), \
154 #define alloc_percpu_noprof(type) \
155 ((typeof(type) __percpu *)pcpu_alloc_noprof(sizeof(type), \
156 __alignof__(type), false, GFP_KERNEL))
158 extern void free_percpu(void __percpu *__pdata);
160 DEFINE_FREE(free_percpu, void __percpu *, free_percpu(_T))
162 extern phys_addr_t per_cpu_ptr_to_phys(void *addr);
164 extern unsigned long pcpu_nr_pages(void);
166 #endif /* __LINUX_PERCPU_H */