OMAP3: SR: Fix init voltage on OPP change
[linux-ginger.git] / include / linux / percpu.h
blob878836ca999c0f3e2b65836cbe8bd7816d44ffaa
1 #ifndef __LINUX_PERCPU_H
2 #define __LINUX_PERCPU_H
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>
10 #include <asm/percpu.h>
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
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
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); \
31 preempt_disable(); \
32 &__get_cpu_var(var); }))
33 #define put_cpu_var(var) preempt_enable()
35 #ifdef CONFIG_SMP
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)
55 #else
56 #define PERCPU_DYNAMIC_RESERVE (12 << 10)
57 #endif
59 extern void *pcpu_base_addr;
60 extern const unsigned long *pcpu_unit_offsets;
62 struct pcpu_group_info {
63 int nr_units; /* aligned # of units */
64 unsigned long base_offset; /* base address offset */
65 unsigned int *cpu_map; /* unit->cpu map, empty
66 * entries contain NR_CPUS */
69 struct pcpu_alloc_info {
70 size_t static_size;
71 size_t reserved_size;
72 size_t dyn_size;
73 size_t unit_size;
74 size_t atom_size;
75 size_t alloc_size;
76 size_t __ai_size; /* internal, don't use */
77 int nr_groups; /* 0 if grouping unnecessary */
78 struct pcpu_group_info groups[];
81 enum pcpu_fc {
82 PCPU_FC_AUTO,
83 PCPU_FC_EMBED,
84 PCPU_FC_PAGE,
86 PCPU_FC_NR,
88 extern const char *pcpu_fc_names[PCPU_FC_NR];
90 extern enum pcpu_fc pcpu_chosen_fc;
92 typedef void * (*pcpu_fc_alloc_fn_t)(unsigned int cpu, size_t size,
93 size_t align);
94 typedef void (*pcpu_fc_free_fn_t)(void *ptr, size_t size);
95 typedef void (*pcpu_fc_populate_pte_fn_t)(unsigned long addr);
96 typedef int (pcpu_fc_cpu_distance_fn_t)(unsigned int from, unsigned int to);
98 extern struct pcpu_alloc_info * __init pcpu_alloc_alloc_info(int nr_groups,
99 int nr_units);
100 extern void __init pcpu_free_alloc_info(struct pcpu_alloc_info *ai);
102 extern struct pcpu_alloc_info * __init pcpu_build_alloc_info(
103 size_t reserved_size, ssize_t dyn_size,
104 size_t atom_size,
105 pcpu_fc_cpu_distance_fn_t cpu_distance_fn);
107 extern int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
108 void *base_addr);
110 #ifdef CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK
111 extern int __init pcpu_embed_first_chunk(size_t reserved_size, ssize_t dyn_size,
112 size_t atom_size,
113 pcpu_fc_cpu_distance_fn_t cpu_distance_fn,
114 pcpu_fc_alloc_fn_t alloc_fn,
115 pcpu_fc_free_fn_t free_fn);
116 #endif
118 #ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK
119 extern int __init pcpu_page_first_chunk(size_t reserved_size,
120 pcpu_fc_alloc_fn_t alloc_fn,
121 pcpu_fc_free_fn_t free_fn,
122 pcpu_fc_populate_pte_fn_t populate_pte_fn);
123 #endif
126 * Use this to get to a cpu's version of the per-cpu object
127 * dynamically allocated. Non-atomic access to the current CPU's
128 * version should probably be combined with get_cpu()/put_cpu().
130 #define per_cpu_ptr(ptr, cpu) SHIFT_PERCPU_PTR((ptr), per_cpu_offset((cpu)))
132 extern void *__alloc_reserved_percpu(size_t size, size_t align);
134 #else /* CONFIG_HAVE_LEGACY_PER_CPU_AREA */
136 struct percpu_data {
137 void *ptrs[1];
140 /* pointer disguising messes up the kmemleak objects tracking */
141 #ifndef CONFIG_DEBUG_KMEMLEAK
142 #define __percpu_disguise(pdata) (struct percpu_data *)~(unsigned long)(pdata)
143 #else
144 #define __percpu_disguise(pdata) (struct percpu_data *)(pdata)
145 #endif
147 #define per_cpu_ptr(ptr, cpu) \
148 ({ \
149 struct percpu_data *__p = __percpu_disguise(ptr); \
150 (__typeof__(ptr))__p->ptrs[(cpu)]; \
153 #endif /* CONFIG_HAVE_LEGACY_PER_CPU_AREA */
155 extern void *__alloc_percpu(size_t size, size_t align);
156 extern void free_percpu(void *__pdata);
158 #ifndef CONFIG_HAVE_SETUP_PER_CPU_AREA
159 extern void __init setup_per_cpu_areas(void);
160 #endif
162 #else /* CONFIG_SMP */
164 #define per_cpu_ptr(ptr, cpu) ({ (void)(cpu); (ptr); })
166 static inline void *__alloc_percpu(size_t size, size_t align)
169 * Can't easily make larger alignment work with kmalloc. WARN
170 * on it. Larger alignment should only be used for module
171 * percpu sections on SMP for which this path isn't used.
173 WARN_ON_ONCE(align > SMP_CACHE_BYTES);
174 return kzalloc(size, GFP_KERNEL);
177 static inline void free_percpu(void *p)
179 kfree(p);
182 static inline void __init setup_per_cpu_areas(void) { }
184 static inline void *pcpu_lpage_remapped(void *kaddr)
186 return NULL;
189 #endif /* CONFIG_SMP */
191 #define alloc_percpu(type) (type *)__alloc_percpu(sizeof(type), \
192 __alignof__(type))
195 * Optional methods for optimized non-lvalue per-cpu variable access.
197 * @var can be a percpu variable or a field of it and its size should
198 * equal char, int or long. percpu_read() evaluates to a lvalue and
199 * all others to void.
201 * These operations are guaranteed to be atomic w.r.t. preemption.
202 * The generic versions use plain get/put_cpu_var(). Archs are
203 * encouraged to implement single-instruction alternatives which don't
204 * require preemption protection.
206 #ifndef percpu_read
207 # define percpu_read(var) \
208 ({ \
209 typeof(per_cpu_var(var)) __tmp_var__; \
210 __tmp_var__ = get_cpu_var(var); \
211 put_cpu_var(var); \
212 __tmp_var__; \
214 #endif
216 #define __percpu_generic_to_op(var, val, op) \
217 do { \
218 get_cpu_var(var) op val; \
219 put_cpu_var(var); \
220 } while (0)
222 #ifndef percpu_write
223 # define percpu_write(var, val) __percpu_generic_to_op(var, (val), =)
224 #endif
226 #ifndef percpu_add
227 # define percpu_add(var, val) __percpu_generic_to_op(var, (val), +=)
228 #endif
230 #ifndef percpu_sub
231 # define percpu_sub(var, val) __percpu_generic_to_op(var, (val), -=)
232 #endif
234 #ifndef percpu_and
235 # define percpu_and(var, val) __percpu_generic_to_op(var, (val), &=)
236 #endif
238 #ifndef percpu_or
239 # define percpu_or(var, val) __percpu_generic_to_op(var, (val), |=)
240 #endif
242 #ifndef percpu_xor
243 # define percpu_xor(var, val) __percpu_generic_to_op(var, (val), ^=)
244 #endif
246 #endif /* __LINUX_PERCPU_H */