1 #ifndef __LINUX_PERCPU_H
2 #define __LINUX_PERCPU_H
4 #include <linux/preempt.h>
5 #include <linux/slab.h> /* For kmalloc() */
7 #include <linux/cpumask.h>
10 #include <asm/percpu.h>
12 /* enough to cover all DEFINE_PER_CPUs in modules */
14 #define PERCPU_MODULE_RESERVE (8 << 10)
16 #define PERCPU_MODULE_RESERVE 0
19 #ifndef PERCPU_ENOUGH_ROOM
20 #define PERCPU_ENOUGH_ROOM \
21 (ALIGN(__per_cpu_end - __per_cpu_start, SMP_CACHE_BYTES) + \
22 PERCPU_MODULE_RESERVE)
26 * Must be an lvalue. Since @var must be a simple identifier,
27 * we force a syntax error here if it isn't.
29 #define get_cpu_var(var) (*({ \
30 extern int simple_identifier_##var(void); \
32 &__get_cpu_var(var); }))
33 #define put_cpu_var(var) preempt_enable()
37 #ifndef CONFIG_HAVE_LEGACY_PER_CPU_AREA
39 /* minimum unit size, also is the maximum supported allocation size */
40 #define PCPU_MIN_UNIT_SIZE PFN_ALIGN(64 << 10)
43 * PERCPU_DYNAMIC_RESERVE indicates the amount of free area to piggy
44 * back on the first chunk for dynamic percpu allocation if arch is
45 * manually allocating and mapping it for faster access (as a part of
46 * large page mapping for example).
48 * The following values give between one and two pages of free space
49 * after typical minimal boot (2-way SMP, single disk and NIC) with
50 * both defconfig and a distro config on x86_64 and 32. More
51 * intelligent way to determine this would be nice.
53 #if BITS_PER_LONG > 32
54 #define PERCPU_DYNAMIC_RESERVE (20 << 10)
56 #define PERCPU_DYNAMIC_RESERVE (12 << 10)
59 extern void *pcpu_base_addr;
60 extern const int *pcpu_unit_map;
70 extern const char *pcpu_fc_names[PCPU_FC_NR];
72 extern enum pcpu_fc pcpu_chosen_fc;
74 typedef void * (*pcpu_fc_alloc_fn_t)(unsigned int cpu, size_t size,
76 typedef void (*pcpu_fc_free_fn_t)(void *ptr, size_t size);
77 typedef void (*pcpu_fc_populate_pte_fn_t)(unsigned long addr);
78 typedef int (pcpu_fc_cpu_distance_fn_t)(unsigned int from, unsigned int to);
79 typedef void (*pcpu_fc_map_fn_t)(void *ptr, size_t size, void *addr);
81 extern size_t __init pcpu_setup_first_chunk(
82 size_t static_size, size_t reserved_size,
83 size_t dyn_size, size_t unit_size,
84 void *base_addr, const int *unit_map);
86 #ifdef CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK
87 extern ssize_t __init pcpu_embed_first_chunk(
88 size_t reserved_size, ssize_t dyn_size);
91 #ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK
92 extern ssize_t __init pcpu_page_first_chunk(
94 pcpu_fc_alloc_fn_t alloc_fn,
95 pcpu_fc_free_fn_t free_fn,
96 pcpu_fc_populate_pte_fn_t populate_pte_fn);
99 #ifdef CONFIG_NEED_PER_CPU_LPAGE_FIRST_CHUNK
100 extern int __init pcpu_lpage_build_unit_map(
101 size_t reserved_size, ssize_t *dyn_sizep,
102 size_t *unit_sizep, size_t lpage_size,
104 pcpu_fc_cpu_distance_fn_t cpu_distance_fn);
106 extern ssize_t __init pcpu_lpage_first_chunk(
107 size_t reserved_size, size_t dyn_size,
108 size_t unit_size, size_t lpage_size,
109 const int *unit_map, int nr_units,
110 pcpu_fc_alloc_fn_t alloc_fn,
111 pcpu_fc_free_fn_t free_fn,
112 pcpu_fc_map_fn_t map_fn);
114 extern void *pcpu_lpage_remapped(void *kaddr);
116 static inline void *pcpu_lpage_remapped(void *kaddr)
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().
127 #define per_cpu_ptr(ptr, cpu) SHIFT_PERCPU_PTR((ptr), per_cpu_offset((cpu)))
129 extern void *__alloc_reserved_percpu(size_t size, size_t align);
131 #else /* CONFIG_HAVE_LEGACY_PER_CPU_AREA */
137 /* pointer disguising messes up the kmemleak objects tracking */
138 #ifndef CONFIG_DEBUG_KMEMLEAK
139 #define __percpu_disguise(pdata) (struct percpu_data *)~(unsigned long)(pdata)
141 #define __percpu_disguise(pdata) (struct percpu_data *)(pdata)
144 #define per_cpu_ptr(ptr, cpu) \
146 struct percpu_data *__p = __percpu_disguise(ptr); \
147 (__typeof__(ptr))__p->ptrs[(cpu)]; \
150 #endif /* CONFIG_HAVE_LEGACY_PER_CPU_AREA */
152 extern void *__alloc_percpu(size_t size, size_t align);
153 extern void free_percpu(void *__pdata);
155 #ifndef CONFIG_HAVE_SETUP_PER_CPU_AREA
156 extern void __init setup_per_cpu_areas(void);
159 #else /* CONFIG_SMP */
161 #define per_cpu_ptr(ptr, cpu) ({ (void)(cpu); (ptr); })
163 static inline void *__alloc_percpu(size_t size, size_t align)
166 * Can't easily make larger alignment work with kmalloc. WARN
167 * on it. Larger alignment should only be used for module
168 * percpu sections on SMP for which this path isn't used.
170 WARN_ON_ONCE(align > SMP_CACHE_BYTES);
171 return kzalloc(size, GFP_KERNEL);
174 static inline void free_percpu(void *p)
179 static inline void __init setup_per_cpu_areas(void) { }
181 static inline void *pcpu_lpage_remapped(void *kaddr)
186 #endif /* CONFIG_SMP */
188 #define alloc_percpu(type) (type *)__alloc_percpu(sizeof(type), \
192 * Optional methods for optimized non-lvalue per-cpu variable access.
194 * @var can be a percpu variable or a field of it and its size should
195 * equal char, int or long. percpu_read() evaluates to a lvalue and
196 * all others to void.
198 * These operations are guaranteed to be atomic w.r.t. preemption.
199 * The generic versions use plain get/put_cpu_var(). Archs are
200 * encouraged to implement single-instruction alternatives which don't
201 * require preemption protection.
204 # define percpu_read(var) \
206 typeof(per_cpu_var(var)) __tmp_var__; \
207 __tmp_var__ = get_cpu_var(var); \
213 #define __percpu_generic_to_op(var, val, op) \
215 get_cpu_var(var) op val; \
220 # define percpu_write(var, val) __percpu_generic_to_op(var, (val), =)
224 # define percpu_add(var, val) __percpu_generic_to_op(var, (val), +=)
228 # define percpu_sub(var, val) __percpu_generic_to_op(var, (val), -=)
232 # define percpu_and(var, val) __percpu_generic_to_op(var, (val), &=)
236 # define percpu_or(var, val) __percpu_generic_to_op(var, (val), |=)
240 # define percpu_xor(var, val) __percpu_generic_to_op(var, (val), ^=)
243 #endif /* __LINUX_PERCPU_H */