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#ifndef PERCPU_ENOUGH_ROOM
22#define PERCPU_ENOUGH_ROOM						\
23	(ALIGN(__per_cpu_end - __per_cpu_start, SMP_CACHE_BYTES) +	\
24	 PERCPU_MODULE_RESERVE)
25#endif
26
27/* minimum unit size, also is the maximum supported allocation size */
28#define PCPU_MIN_UNIT_SIZE		PFN_ALIGN(32 << 10)
29
30/*
31 * Percpu allocator can serve percpu allocations before slab is
32 * initialized which allows slab to depend on the percpu allocator.
33 * The following two parameters decide how much resource to
34 * preallocate for this.  Keep PERCPU_DYNAMIC_RESERVE equal to or
35 * larger than PERCPU_DYNAMIC_EARLY_SIZE.
36 */
37#define PERCPU_DYNAMIC_EARLY_SLOTS	128
38#define PERCPU_DYNAMIC_EARLY_SIZE	(12 << 10)
39
40/*
41 * PERCPU_DYNAMIC_RESERVE indicates the amount of free area to piggy
42 * back on the first chunk for dynamic percpu allocation if arch is
43 * manually allocating and mapping it for faster access (as a part of
44 * large page mapping for example).
45 *
46 * The following values give between one and two pages of free space
47 * after typical minimal boot (2-way SMP, single disk and NIC) with
48 * both defconfig and a distro config on x86_64 and 32.  More
49 * intelligent way to determine this would be nice.
50 */
51#if BITS_PER_LONG > 32
52#define PERCPU_DYNAMIC_RESERVE		(28 << 10)
53#else
54#define PERCPU_DYNAMIC_RESERVE		(20 << 10)
55#endif
56
57extern void *pcpu_base_addr;
58extern const unsigned long *pcpu_unit_offsets;
59
60struct pcpu_group_info {
61	int			nr_units;	/* aligned # of units */
62	unsigned long		base_offset;	/* base address offset */
63	unsigned int		*cpu_map;	/* unit->cpu map, empty
64						 * entries contain NR_CPUS */
65};
66
67struct pcpu_alloc_info {
68	size_t			static_size;
69	size_t			reserved_size;
70	size_t			dyn_size;
71	size_t			unit_size;
72	size_t			atom_size;
73	size_t			alloc_size;
74	size_t			__ai_size;	/* internal, don't use */
75	int			nr_groups;	/* 0 if grouping unnecessary */
76	struct pcpu_group_info	groups[];
77};
78
79enum pcpu_fc {
80	PCPU_FC_AUTO,
81	PCPU_FC_EMBED,
82	PCPU_FC_PAGE,
83
84	PCPU_FC_NR,
85};
86extern const char * const pcpu_fc_names[PCPU_FC_NR];
87
88extern enum pcpu_fc pcpu_chosen_fc;
89
90typedef void * (*pcpu_fc_alloc_fn_t)(unsigned int cpu, size_t size,
91				     size_t align);
92typedef void (*pcpu_fc_free_fn_t)(void *ptr, size_t size);
93typedef void (*pcpu_fc_populate_pte_fn_t)(unsigned long addr);
94typedef int (pcpu_fc_cpu_distance_fn_t)(unsigned int from, unsigned int to);
95
96extern struct pcpu_alloc_info * __init pcpu_alloc_alloc_info(int nr_groups,
97							     int nr_units);
98extern void __init pcpu_free_alloc_info(struct pcpu_alloc_info *ai);
99
100extern int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
101					 void *base_addr);
102
103#ifdef CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK
104extern int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size,
105				size_t atom_size,
106				pcpu_fc_cpu_distance_fn_t cpu_distance_fn,
107				pcpu_fc_alloc_fn_t alloc_fn,
108				pcpu_fc_free_fn_t free_fn);
109#endif
110
111#ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK
112extern int __init pcpu_page_first_chunk(size_t reserved_size,
113				pcpu_fc_alloc_fn_t alloc_fn,
114				pcpu_fc_free_fn_t free_fn,
115				pcpu_fc_populate_pte_fn_t populate_pte_fn);
116#endif
117
118extern void __percpu *__alloc_reserved_percpu(size_t size, size_t align);
119extern bool is_kernel_percpu_address(unsigned long addr);
120
121#if !defined(CONFIG_SMP) || !defined(CONFIG_HAVE_SETUP_PER_CPU_AREA)
122extern void __init setup_per_cpu_areas(void);
123#endif
124extern void __init percpu_init_late(void);
125
126extern void __percpu *__alloc_percpu_gfp(size_t size, size_t align, gfp_t gfp);
127extern void __percpu *__alloc_percpu(size_t size, size_t align);
128extern void free_percpu(void __percpu *__pdata);
129extern phys_addr_t per_cpu_ptr_to_phys(void *addr);
130
131#define alloc_percpu_gfp(type, gfp)					\
132	(typeof(type) __percpu *)__alloc_percpu_gfp(sizeof(type),	\
133						__alignof__(type), gfp)
134#define alloc_percpu(type)						\
135	(typeof(type) __percpu *)__alloc_percpu(sizeof(type),		\
136						__alignof__(type))
137
138/* To avoid include hell, as printk can not declare this, we declare it here */
139DECLARE_PER_CPU(printk_func_t, printk_func);
140
141#endif /* __LINUX_PERCPU_H */
142