percpu: drop @static_size from first chunk allocators
[linux-2.6.git] / include / linux / percpu.h
1 #ifndef __LINUX_PERCPU_H
2 #define __LINUX_PERCPU_H
3
4 #include <linux/preempt.h>
5 #include <linux/slab.h> /* For kmalloc() */
6 #include <linux/smp.h>
7 #include <linux/cpumask.h>
8 #include <linux/pfn.h>
9
10 #include <asm/percpu.h>
11
12 /* enough to cover all DEFINE_PER_CPUs in modules */
13 #ifdef CONFIG_MODULES
14 #define PERCPU_MODULE_RESERVE           (8 << 10)
15 #else
16 #define PERCPU_MODULE_RESERVE           0
17 #endif
18
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)
23 #endif
24
25 /*
26  * Must be an lvalue. Since @var must be a simple identifier,
27  * we force a syntax error here if it isn't.
28  */
29 #define get_cpu_var(var) (*({                           \
30         extern int simple_identifier_##var(void);       \
31         preempt_disable();                              \
32         &__get_cpu_var(var); }))
33 #define put_cpu_var(var) preempt_enable()
34
35 #ifdef CONFIG_SMP
36
37 #ifndef CONFIG_HAVE_LEGACY_PER_CPU_AREA
38
39 /* minimum unit size, also is the maximum supported allocation size */
40 #define PCPU_MIN_UNIT_SIZE              PFN_ALIGN(64 << 10)
41
42 /*
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).
47  *
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.
52  */
53 #if BITS_PER_LONG > 32
54 #define PERCPU_DYNAMIC_RESERVE          (20 << 10)
55 #else
56 #define PERCPU_DYNAMIC_RESERVE          (12 << 10)
57 #endif
58
59 extern void *pcpu_base_addr;
60 extern const int *pcpu_unit_map;
61
62 enum pcpu_fc {
63         PCPU_FC_AUTO,
64         PCPU_FC_EMBED,
65         PCPU_FC_PAGE,
66         PCPU_FC_LPAGE,
67
68         PCPU_FC_NR,
69 };
70 extern const char *pcpu_fc_names[PCPU_FC_NR];
71
72 extern enum pcpu_fc pcpu_chosen_fc;
73
74 typedef void * (*pcpu_fc_alloc_fn_t)(unsigned int cpu, size_t size);
75 typedef void (*pcpu_fc_free_fn_t)(void *ptr, size_t size);
76 typedef void (*pcpu_fc_populate_pte_fn_t)(unsigned long addr);
77 typedef int (pcpu_fc_cpu_distance_fn_t)(unsigned int from, unsigned int to);
78 typedef void (*pcpu_fc_map_fn_t)(void *ptr, size_t size, void *addr);
79
80 extern size_t __init pcpu_setup_first_chunk(
81                                 size_t static_size, size_t reserved_size,
82                                 ssize_t dyn_size, size_t unit_size,
83                                 void *base_addr, const int *unit_map);
84
85 #ifdef CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK
86 extern ssize_t __init pcpu_embed_first_chunk(
87                                 size_t reserved_size, ssize_t dyn_size);
88 #endif
89
90 #ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK
91 extern ssize_t __init pcpu_page_first_chunk(
92                                 size_t reserved_size,
93                                 pcpu_fc_alloc_fn_t alloc_fn,
94                                 pcpu_fc_free_fn_t free_fn,
95                                 pcpu_fc_populate_pte_fn_t populate_pte_fn);
96 #endif
97
98 #ifdef CONFIG_NEED_PER_CPU_LPAGE_FIRST_CHUNK
99 extern int __init pcpu_lpage_build_unit_map(
100                                 size_t reserved_size, ssize_t *dyn_sizep,
101                                 size_t *unit_sizep, size_t lpage_size,
102                                 int *unit_map,
103                                 pcpu_fc_cpu_distance_fn_t cpu_distance_fn);
104
105 extern ssize_t __init pcpu_lpage_first_chunk(
106                                 size_t reserved_size, size_t dyn_size,
107                                 size_t unit_size, size_t lpage_size,
108                                 const int *unit_map, int nr_units,
109                                 pcpu_fc_alloc_fn_t alloc_fn,
110                                 pcpu_fc_free_fn_t free_fn,
111                                 pcpu_fc_map_fn_t map_fn);
112
113 extern void *pcpu_lpage_remapped(void *kaddr);
114 #else
115 static inline void *pcpu_lpage_remapped(void *kaddr)
116 {
117         return NULL;
118 }
119 #endif
120
121 /*
122  * Use this to get to a cpu's version of the per-cpu object
123  * dynamically allocated. Non-atomic access to the current CPU's
124  * version should probably be combined with get_cpu()/put_cpu().
125  */
126 #define per_cpu_ptr(ptr, cpu)   SHIFT_PERCPU_PTR((ptr), per_cpu_offset((cpu)))
127
128 extern void *__alloc_reserved_percpu(size_t size, size_t align);
129
130 #else /* CONFIG_HAVE_LEGACY_PER_CPU_AREA */
131
132 struct percpu_data {
133         void *ptrs[1];
134 };
135
136 /* pointer disguising messes up the kmemleak objects tracking */
137 #ifndef CONFIG_DEBUG_KMEMLEAK
138 #define __percpu_disguise(pdata) (struct percpu_data *)~(unsigned long)(pdata)
139 #else
140 #define __percpu_disguise(pdata) (struct percpu_data *)(pdata)
141 #endif
142
143 #define per_cpu_ptr(ptr, cpu)                                           \
144 ({                                                                      \
145         struct percpu_data *__p = __percpu_disguise(ptr);               \
146         (__typeof__(ptr))__p->ptrs[(cpu)];                              \
147 })
148
149 #endif /* CONFIG_HAVE_LEGACY_PER_CPU_AREA */
150
151 extern void *__alloc_percpu(size_t size, size_t align);
152 extern void free_percpu(void *__pdata);
153
154 #ifndef CONFIG_HAVE_SETUP_PER_CPU_AREA
155 extern void __init setup_per_cpu_areas(void);
156 #endif
157
158 #else /* CONFIG_SMP */
159
160 #define per_cpu_ptr(ptr, cpu) ({ (void)(cpu); (ptr); })
161
162 static inline void *__alloc_percpu(size_t size, size_t align)
163 {
164         /*
165          * Can't easily make larger alignment work with kmalloc.  WARN
166          * on it.  Larger alignment should only be used for module
167          * percpu sections on SMP for which this path isn't used.
168          */
169         WARN_ON_ONCE(align > SMP_CACHE_BYTES);
170         return kzalloc(size, GFP_KERNEL);
171 }
172
173 static inline void free_percpu(void *p)
174 {
175         kfree(p);
176 }
177
178 static inline void __init setup_per_cpu_areas(void) { }
179
180 static inline void *pcpu_lpage_remapped(void *kaddr)
181 {
182         return NULL;
183 }
184
185 #endif /* CONFIG_SMP */
186
187 #define alloc_percpu(type)      (type *)__alloc_percpu(sizeof(type), \
188                                                        __alignof__(type))
189
190 /*
191  * Optional methods for optimized non-lvalue per-cpu variable access.
192  *
193  * @var can be a percpu variable or a field of it and its size should
194  * equal char, int or long.  percpu_read() evaluates to a lvalue and
195  * all others to void.
196  *
197  * These operations are guaranteed to be atomic w.r.t. preemption.
198  * The generic versions use plain get/put_cpu_var().  Archs are
199  * encouraged to implement single-instruction alternatives which don't
200  * require preemption protection.
201  */
202 #ifndef percpu_read
203 # define percpu_read(var)                                               \
204   ({                                                                    \
205         typeof(per_cpu_var(var)) __tmp_var__;                           \
206         __tmp_var__ = get_cpu_var(var);                                 \
207         put_cpu_var(var);                                               \
208         __tmp_var__;                                                    \
209   })
210 #endif
211
212 #define __percpu_generic_to_op(var, val, op)                            \
213 do {                                                                    \
214         get_cpu_var(var) op val;                                        \
215         put_cpu_var(var);                                               \
216 } while (0)
217
218 #ifndef percpu_write
219 # define percpu_write(var, val)         __percpu_generic_to_op(var, (val), =)
220 #endif
221
222 #ifndef percpu_add
223 # define percpu_add(var, val)           __percpu_generic_to_op(var, (val), +=)
224 #endif
225
226 #ifndef percpu_sub
227 # define percpu_sub(var, val)           __percpu_generic_to_op(var, (val), -=)
228 #endif
229
230 #ifndef percpu_and
231 # define percpu_and(var, val)           __percpu_generic_to_op(var, (val), &=)
232 #endif
233
234 #ifndef percpu_or
235 # define percpu_or(var, val)            __percpu_generic_to_op(var, (val), |=)
236 #endif
237
238 #ifndef percpu_xor
239 # define percpu_xor(var, val)           __percpu_generic_to_op(var, (val), ^=)
240 #endif
241
242 #endif /* __LINUX_PERCPU_H */