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-rw-r--r--include/linux/percpu.h159
1 files changed, 107 insertions, 52 deletions
diff --git a/include/linux/percpu.h b/include/linux/percpu.h
index 9f2a3751873a..ee5615d65211 100644
--- a/include/linux/percpu.h
+++ b/include/linux/percpu.h
@@ -5,53 +5,66 @@
5#include <linux/slab.h> /* For kmalloc() */ 5#include <linux/slab.h> /* For kmalloc() */
6#include <linux/smp.h> 6#include <linux/smp.h>
7#include <linux/cpumask.h> 7#include <linux/cpumask.h>
8#include <linux/pfn.h>
8 9
9#include <asm/percpu.h> 10#include <asm/percpu.h>
10 11
12#ifndef PER_CPU_BASE_SECTION
13#ifdef CONFIG_SMP
14#define PER_CPU_BASE_SECTION ".data.percpu"
15#else
16#define PER_CPU_BASE_SECTION ".data"
17#endif
18#endif
19
11#ifdef CONFIG_SMP 20#ifdef CONFIG_SMP
12#define DEFINE_PER_CPU(type, name) \
13 __attribute__((__section__(".data.percpu"))) \
14 PER_CPU_ATTRIBUTES __typeof__(type) per_cpu__##name
15 21
16#ifdef MODULE 22#ifdef MODULE
17#define SHARED_ALIGNED_SECTION ".data.percpu" 23#define PER_CPU_SHARED_ALIGNED_SECTION ""
18#else 24#else
19#define SHARED_ALIGNED_SECTION ".data.percpu.shared_aligned" 25#define PER_CPU_SHARED_ALIGNED_SECTION ".shared_aligned"
20#endif 26#endif
27#define PER_CPU_FIRST_SECTION ".first"
21 28
22#define DEFINE_PER_CPU_SHARED_ALIGNED(type, name) \ 29#else
23 __attribute__((__section__(SHARED_ALIGNED_SECTION))) \ 30
24 PER_CPU_ATTRIBUTES __typeof__(type) per_cpu__##name \ 31#define PER_CPU_SHARED_ALIGNED_SECTION ""
25 ____cacheline_aligned_in_smp 32#define PER_CPU_FIRST_SECTION ""
26 33
27#define DEFINE_PER_CPU_PAGE_ALIGNED(type, name) \ 34#endif
28 __attribute__((__section__(".data.percpu.page_aligned"))) \ 35
36#define DEFINE_PER_CPU_SECTION(type, name, section) \
37 __attribute__((__section__(PER_CPU_BASE_SECTION section))) \
29 PER_CPU_ATTRIBUTES __typeof__(type) per_cpu__##name 38 PER_CPU_ATTRIBUTES __typeof__(type) per_cpu__##name
30#else 39
31#define DEFINE_PER_CPU(type, name) \ 40#define DEFINE_PER_CPU(type, name) \
32 PER_CPU_ATTRIBUTES __typeof__(type) per_cpu__##name 41 DEFINE_PER_CPU_SECTION(type, name, "")
33 42
34#define DEFINE_PER_CPU_SHARED_ALIGNED(type, name) \ 43#define DEFINE_PER_CPU_SHARED_ALIGNED(type, name) \
35 DEFINE_PER_CPU(type, name) 44 DEFINE_PER_CPU_SECTION(type, name, PER_CPU_SHARED_ALIGNED_SECTION) \
45 ____cacheline_aligned_in_smp
36 46
37#define DEFINE_PER_CPU_PAGE_ALIGNED(type, name) \ 47#define DEFINE_PER_CPU_PAGE_ALIGNED(type, name) \
38 DEFINE_PER_CPU(type, name) 48 DEFINE_PER_CPU_SECTION(type, name, ".page_aligned")
39#endif 49
50#define DEFINE_PER_CPU_FIRST(type, name) \
51 DEFINE_PER_CPU_SECTION(type, name, PER_CPU_FIRST_SECTION)
40 52
41#define EXPORT_PER_CPU_SYMBOL(var) EXPORT_SYMBOL(per_cpu__##var) 53#define EXPORT_PER_CPU_SYMBOL(var) EXPORT_SYMBOL(per_cpu__##var)
42#define EXPORT_PER_CPU_SYMBOL_GPL(var) EXPORT_SYMBOL_GPL(per_cpu__##var) 54#define EXPORT_PER_CPU_SYMBOL_GPL(var) EXPORT_SYMBOL_GPL(per_cpu__##var)
43 55
44/* Enough to cover all DEFINE_PER_CPUs in kernel, including modules. */ 56/* enough to cover all DEFINE_PER_CPUs in modules */
45#ifndef PERCPU_ENOUGH_ROOM
46#ifdef CONFIG_MODULES 57#ifdef CONFIG_MODULES
47#define PERCPU_MODULE_RESERVE 8192 58#define PERCPU_MODULE_RESERVE (8 << 10)
48#else 59#else
49#define PERCPU_MODULE_RESERVE 0 60#define PERCPU_MODULE_RESERVE 0
50#endif 61#endif
51 62
63#ifndef PERCPU_ENOUGH_ROOM
52#define PERCPU_ENOUGH_ROOM \ 64#define PERCPU_ENOUGH_ROOM \
53 (__per_cpu_end - __per_cpu_start + PERCPU_MODULE_RESERVE) 65 (ALIGN(__per_cpu_end - __per_cpu_start, SMP_CACHE_BYTES) + \
54#endif /* PERCPU_ENOUGH_ROOM */ 66 PERCPU_MODULE_RESERVE)
67#endif
55 68
56/* 69/*
57 * Must be an lvalue. Since @var must be a simple identifier, 70 * Must be an lvalue. Since @var must be a simple identifier,
@@ -65,52 +78,94 @@
65 78
66#ifdef CONFIG_SMP 79#ifdef CONFIG_SMP
67 80
81#ifdef CONFIG_HAVE_DYNAMIC_PER_CPU_AREA
82
83/* minimum unit size, also is the maximum supported allocation size */
84#define PCPU_MIN_UNIT_SIZE PFN_ALIGN(64 << 10)
85
86/*
87 * PERCPU_DYNAMIC_RESERVE indicates the amount of free area to piggy
88 * back on the first chunk for dynamic percpu allocation if arch is
89 * manually allocating and mapping it for faster access (as a part of
90 * large page mapping for example).
91 *
92 * The following values give between one and two pages of free space
93 * after typical minimal boot (2-way SMP, single disk and NIC) with
94 * both defconfig and a distro config on x86_64 and 32. More
95 * intelligent way to determine this would be nice.
96 */
97#if BITS_PER_LONG > 32
98#define PERCPU_DYNAMIC_RESERVE (20 << 10)
99#else
100#define PERCPU_DYNAMIC_RESERVE (12 << 10)
101#endif
102
103extern void *pcpu_base_addr;
104
105typedef struct page * (*pcpu_get_page_fn_t)(unsigned int cpu, int pageno);
106typedef void (*pcpu_populate_pte_fn_t)(unsigned long addr);
107
108extern size_t __init pcpu_setup_first_chunk(pcpu_get_page_fn_t get_page_fn,
109 size_t static_size, size_t reserved_size,
110 ssize_t dyn_size, ssize_t unit_size,
111 void *base_addr,
112 pcpu_populate_pte_fn_t populate_pte_fn);
113
114extern ssize_t __init pcpu_embed_first_chunk(
115 size_t static_size, size_t reserved_size,
116 ssize_t dyn_size, ssize_t unit_size);
117
118/*
119 * Use this to get to a cpu's version of the per-cpu object
120 * dynamically allocated. Non-atomic access to the current CPU's
121 * version should probably be combined with get_cpu()/put_cpu().
122 */
123#define per_cpu_ptr(ptr, cpu) SHIFT_PERCPU_PTR((ptr), per_cpu_offset((cpu)))
124
125extern void *__alloc_reserved_percpu(size_t size, size_t align);
126
127#else /* CONFIG_HAVE_DYNAMIC_PER_CPU_AREA */
128
68struct percpu_data { 129struct percpu_data {
69 void *ptrs[1]; 130 void *ptrs[1];
70}; 131};
71 132
72#define __percpu_disguise(pdata) (struct percpu_data *)~(unsigned long)(pdata) 133#define __percpu_disguise(pdata) (struct percpu_data *)~(unsigned long)(pdata)
73/* 134
74 * Use this to get to a cpu's version of the per-cpu object dynamically 135#define per_cpu_ptr(ptr, cpu) \
75 * allocated. Non-atomic access to the current CPU's version should 136({ \
76 * probably be combined with get_cpu()/put_cpu(). 137 struct percpu_data *__p = __percpu_disguise(ptr); \
77 */ 138 (__typeof__(ptr))__p->ptrs[(cpu)]; \
78#define percpu_ptr(ptr, cpu) \
79({ \
80 struct percpu_data *__p = __percpu_disguise(ptr); \
81 (__typeof__(ptr))__p->ptrs[(cpu)]; \
82}) 139})
83 140
84extern void *__percpu_alloc_mask(size_t size, gfp_t gfp, cpumask_t *mask); 141#endif /* CONFIG_HAVE_DYNAMIC_PER_CPU_AREA */
85extern void percpu_free(void *__pdata); 142
143extern void *__alloc_percpu(size_t size, size_t align);
144extern void free_percpu(void *__pdata);
86 145
87#else /* CONFIG_SMP */ 146#else /* CONFIG_SMP */
88 147
89#define percpu_ptr(ptr, cpu) ({ (void)(cpu); (ptr); }) 148#define per_cpu_ptr(ptr, cpu) ({ (void)(cpu); (ptr); })
90 149
91static __always_inline void *__percpu_alloc_mask(size_t size, gfp_t gfp, cpumask_t *mask) 150static inline void *__alloc_percpu(size_t size, size_t align)
92{ 151{
93 return kzalloc(size, gfp); 152 /*
153 * Can't easily make larger alignment work with kmalloc. WARN
154 * on it. Larger alignment should only be used for module
155 * percpu sections on SMP for which this path isn't used.
156 */
157 WARN_ON_ONCE(align > SMP_CACHE_BYTES);
158 return kzalloc(size, GFP_KERNEL);
94} 159}
95 160
96static inline void percpu_free(void *__pdata) 161static inline void free_percpu(void *p)
97{ 162{
98 kfree(__pdata); 163 kfree(p);
99} 164}
100 165
101#endif /* CONFIG_SMP */ 166#endif /* CONFIG_SMP */
102 167
103#define percpu_alloc_mask(size, gfp, mask) \ 168#define alloc_percpu(type) (type *)__alloc_percpu(sizeof(type), \
104 __percpu_alloc_mask((size), (gfp), &(mask)) 169 __alignof__(type))
105
106#define percpu_alloc(size, gfp) percpu_alloc_mask((size), (gfp), cpu_online_map)
107
108/* (legacy) interface for use without CPU hotplug handling */
109
110#define __alloc_percpu(size) percpu_alloc_mask((size), GFP_KERNEL, \
111 cpu_possible_map)
112#define alloc_percpu(type) (type *)__alloc_percpu(sizeof(type))
113#define free_percpu(ptr) percpu_free((ptr))
114#define per_cpu_ptr(ptr, cpu) percpu_ptr((ptr), (cpu))
115 170
116#endif /* __LINUX_PERCPU_H */ 171#endif /* __LINUX_PERCPU_H */