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-rw-r--r--include/linux/percpu.h100
1 files changed, 73 insertions, 27 deletions
diff --git a/include/linux/percpu.h b/include/linux/percpu.h
index 3577ffd90d45..910beb0abea2 100644
--- a/include/linux/percpu.h
+++ b/include/linux/percpu.h
@@ -76,52 +76,98 @@
76 76
77#ifdef CONFIG_SMP 77#ifdef CONFIG_SMP
78 78
79#ifdef CONFIG_HAVE_DYNAMIC_PER_CPU_AREA
80
81/* minimum unit size, also is the maximum supported allocation size */
82#define PCPU_MIN_UNIT_SIZE (16UL << PAGE_SHIFT)
83
84/*
85 * PERCPU_DYNAMIC_RESERVE indicates the amount of free area to piggy
86 * back on the first chunk if arch is manually allocating and mapping
87 * it for faster access (as a part of large page mapping for example).
88 * Note that dynamic percpu allocator covers both static and dynamic
89 * areas, so these values are bigger than PERCPU_MODULE_RESERVE.
90 *
91 * On typical configuration with modules, the following values leave
92 * about 8k of free space on the first chunk after boot on both x86_32
93 * and 64 when module support is enabled. When module support is
94 * disabled, it's much tighter.
95 */
96#ifndef PERCPU_DYNAMIC_RESERVE
97# if BITS_PER_LONG > 32
98# ifdef CONFIG_MODULES
99# define PERCPU_DYNAMIC_RESERVE (6 << PAGE_SHIFT)
100# else
101# define PERCPU_DYNAMIC_RESERVE (4 << PAGE_SHIFT)
102# endif
103# else
104# ifdef CONFIG_MODULES
105# define PERCPU_DYNAMIC_RESERVE (4 << PAGE_SHIFT)
106# else
107# define PERCPU_DYNAMIC_RESERVE (2 << PAGE_SHIFT)
108# endif
109# endif
110#endif /* PERCPU_DYNAMIC_RESERVE */
111
112extern void *pcpu_base_addr;
113
114typedef struct page * (*pcpu_get_page_fn_t)(unsigned int cpu, int pageno);
115typedef void (*pcpu_populate_pte_fn_t)(unsigned long addr);
116
117extern size_t __init pcpu_setup_first_chunk(pcpu_get_page_fn_t get_page_fn,
118 size_t static_size, size_t unit_size,
119 size_t free_size, void *base_addr,
120 pcpu_populate_pte_fn_t populate_pte_fn);
121
122/*
123 * Use this to get to a cpu's version of the per-cpu object
124 * dynamically allocated. Non-atomic access to the current CPU's
125 * version should probably be combined with get_cpu()/put_cpu().
126 */
127#define per_cpu_ptr(ptr, cpu) SHIFT_PERCPU_PTR((ptr), per_cpu_offset((cpu)))
128
129#else /* CONFIG_HAVE_DYNAMIC_PER_CPU_AREA */
130
79struct percpu_data { 131struct percpu_data {
80 void *ptrs[1]; 132 void *ptrs[1];
81}; 133};
82 134
83#define __percpu_disguise(pdata) (struct percpu_data *)~(unsigned long)(pdata) 135#define __percpu_disguise(pdata) (struct percpu_data *)~(unsigned long)(pdata)
84/* 136
85 * Use this to get to a cpu's version of the per-cpu object dynamically 137#define per_cpu_ptr(ptr, cpu) \
86 * allocated. Non-atomic access to the current CPU's version should 138({ \
87 * probably be combined with get_cpu()/put_cpu(). 139 struct percpu_data *__p = __percpu_disguise(ptr); \
88 */ 140 (__typeof__(ptr))__p->ptrs[(cpu)]; \
89#define percpu_ptr(ptr, cpu) \
90({ \
91 struct percpu_data *__p = __percpu_disguise(ptr); \
92 (__typeof__(ptr))__p->ptrs[(cpu)]; \
93}) 141})
94 142
95extern void *__percpu_alloc_mask(size_t size, gfp_t gfp, cpumask_t *mask); 143#endif /* CONFIG_HAVE_DYNAMIC_PER_CPU_AREA */
96extern void percpu_free(void *__pdata); 144
145extern void *__alloc_percpu(size_t size, size_t align);
146extern void free_percpu(void *__pdata);
97 147
98#else /* CONFIG_SMP */ 148#else /* CONFIG_SMP */
99 149
100#define percpu_ptr(ptr, cpu) ({ (void)(cpu); (ptr); }) 150#define per_cpu_ptr(ptr, cpu) ({ (void)(cpu); (ptr); })
101 151
102static __always_inline void *__percpu_alloc_mask(size_t size, gfp_t gfp, cpumask_t *mask) 152static inline void *__alloc_percpu(size_t size, size_t align)
103{ 153{
154 /*
155 * Can't easily make larger alignment work with kmalloc. WARN
156 * on it. Larger alignment should only be used for module
157 * percpu sections on SMP for which this path isn't used.
158 */
159 WARN_ON_ONCE(align > __alignof__(unsigned long long));
104 return kzalloc(size, gfp); 160 return kzalloc(size, gfp);
105} 161}
106 162
107static inline void percpu_free(void *__pdata) 163static inline void free_percpu(void *p)
108{ 164{
109 kfree(__pdata); 165 kfree(p);
110} 166}
111 167
112#endif /* CONFIG_SMP */ 168#endif /* CONFIG_SMP */
113 169
114#define percpu_alloc_mask(size, gfp, mask) \ 170#define alloc_percpu(type) (type *)__alloc_percpu(sizeof(type), \
115 __percpu_alloc_mask((size), (gfp), &(mask)) 171 __alignof__(type))
116
117#define percpu_alloc(size, gfp) percpu_alloc_mask((size), (gfp), cpu_online_map)
118
119/* (legacy) interface for use without CPU hotplug handling */
120
121#define __alloc_percpu(size) percpu_alloc_mask((size), GFP_KERNEL, \
122 cpu_possible_map)
123#define alloc_percpu(type) (type *)__alloc_percpu(sizeof(type))
124#define free_percpu(ptr) percpu_free((ptr))
125#define per_cpu_ptr(ptr, cpu) percpu_ptr((ptr), (cpu))
126 172
127#endif /* __LINUX_PERCPU_H */ 173#endif /* __LINUX_PERCPU_H */