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