1 #ifndef __LINUX_PERCPU_H
2 #define __LINUX_PERCPU_H
4 #include <linux/mmdebug.h>
5 #include <linux/preempt.h>
7 #include <linux/cpumask.h>
8 #include <linux/printk.h>
10 #include <linux/init.h>
12 #include <asm/percpu.h>
14 /* enough to cover all DEFINE_PER_CPUs in modules */
16 #define PERCPU_MODULE_RESERVE (8 << 10)
18 #define PERCPU_MODULE_RESERVE 0
21 /* minimum unit size, also is the maximum supported allocation size */
22 #define PCPU_MIN_UNIT_SIZE PFN_ALIGN(32 << 10)
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)
28 /* number of bits per page, used to trigger a scan if blocks are > PAGE_SIZE */
29 #define PCPU_BITS_PER_PAGE (PAGE_SIZE >> PCPU_MIN_ALLOC_SHIFT)
32 * This determines the size of each metadata block. There are several subtle
33 * constraints around this constant. The reserved region must be a multiple of
34 * PCPU_BITMAP_BLOCK_SIZE. Additionally, PCPU_BITMAP_BLOCK_SIZE must be a
35 * multiple of PAGE_SIZE or PAGE_SIZE must be a multiple of
36 * PCPU_BITMAP_BLOCK_SIZE to align with the populated page map. The unit_size
37 * also has to be a multiple of PCPU_BITMAP_BLOCK_SIZE to ensure full blocks.
39 #define PCPU_BITMAP_BLOCK_SIZE PAGE_SIZE
40 #define PCPU_BITMAP_BLOCK_BITS (PCPU_BITMAP_BLOCK_SIZE >> \
44 * Percpu allocator can serve percpu allocations before slab is
45 * initialized which allows slab to depend on the percpu allocator.
46 * The following two parameters decide how much resource to
47 * preallocate for this. Keep PERCPU_DYNAMIC_RESERVE equal to or
48 * larger than PERCPU_DYNAMIC_EARLY_SIZE.
50 #define PERCPU_DYNAMIC_EARLY_SLOTS 128
51 #define PERCPU_DYNAMIC_EARLY_SIZE (12 << 10)
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 << 10)
67 #define PERCPU_DYNAMIC_RESERVE (20 << 10)
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 void * (*pcpu_fc_alloc_fn_t)(unsigned int cpu, size_t size,
105 typedef void (*pcpu_fc_free_fn_t)(void *ptr, size_t size);
106 typedef void (*pcpu_fc_populate_pte_fn_t)(unsigned long addr);
107 typedef int (pcpu_fc_cpu_distance_fn_t)(unsigned int from, unsigned int to);
109 extern struct pcpu_alloc_info * __init pcpu_alloc_alloc_info(int nr_groups,
111 extern void __init pcpu_free_alloc_info(struct pcpu_alloc_info *ai);
113 extern int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
116 #ifdef CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK
117 extern int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size,
119 pcpu_fc_cpu_distance_fn_t cpu_distance_fn,
120 pcpu_fc_alloc_fn_t alloc_fn,
121 pcpu_fc_free_fn_t free_fn);
124 #ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK
125 extern int __init pcpu_page_first_chunk(size_t reserved_size,
126 pcpu_fc_alloc_fn_t alloc_fn,
127 pcpu_fc_free_fn_t free_fn,
128 pcpu_fc_populate_pte_fn_t populate_pte_fn);
131 extern void __percpu *__alloc_reserved_percpu(size_t size, size_t align);
132 extern bool __is_kernel_percpu_address(unsigned long addr, unsigned long *can_addr);
133 extern bool is_kernel_percpu_address(unsigned long addr);
135 #if !defined(CONFIG_SMP) || !defined(CONFIG_HAVE_SETUP_PER_CPU_AREA)
136 extern void __init setup_per_cpu_areas(void);
139 extern void __percpu *__alloc_percpu_gfp(size_t size, size_t align, gfp_t gfp);
140 extern void __percpu *__alloc_percpu(size_t size, size_t align);
141 extern void free_percpu(void __percpu *__pdata);
142 extern phys_addr_t per_cpu_ptr_to_phys(void *addr);
144 #define alloc_percpu_gfp(type, gfp) \
145 (typeof(type) __percpu *)__alloc_percpu_gfp(sizeof(type), \
146 __alignof__(type), gfp)
147 #define alloc_percpu(type) \
148 (typeof(type) __percpu *)__alloc_percpu(sizeof(type), \
151 #endif /* __LINUX_PERCPU_H */