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;
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 {
76 size_t __ai_size; /* internal, don't use */
77 int nr_groups; /* 0 if grouping unnecessary */
78 struct pcpu_group_info groups[];
89 extern const char *pcpu_fc_names[PCPU_FC_NR];
91 extern enum pcpu_fc pcpu_chosen_fc;
93 typedef void * (*pcpu_fc_alloc_fn_t)(unsigned int cpu, size_t size,
95 typedef void (*pcpu_fc_free_fn_t)(void *ptr, size_t size);
96 typedef void (*pcpu_fc_populate_pte_fn_t)(unsigned long addr);
97 typedef int (pcpu_fc_cpu_distance_fn_t)(unsigned int from, unsigned int to);
98 typedef void (*pcpu_fc_map_fn_t)(void *ptr, size_t size, void *addr);
100 extern struct pcpu_alloc_info * __init pcpu_alloc_alloc_info(int nr_groups,
102 extern void __init pcpu_free_alloc_info(struct pcpu_alloc_info *ai);
104 extern struct pcpu_alloc_info * __init pcpu_build_alloc_info(
105 size_t reserved_size, ssize_t dyn_size,
107 pcpu_fc_cpu_distance_fn_t cpu_distance_fn);
109 extern size_t __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
112 #ifdef CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK
113 extern ssize_t __init pcpu_embed_first_chunk(
114 size_t reserved_size, ssize_t dyn_size);
117 #ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK
118 extern ssize_t __init pcpu_page_first_chunk(
119 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);
125 #ifdef CONFIG_NEED_PER_CPU_LPAGE_FIRST_CHUNK
126 extern ssize_t __init pcpu_lpage_first_chunk(
127 const struct pcpu_alloc_info *ai,
128 pcpu_fc_alloc_fn_t alloc_fn,
129 pcpu_fc_free_fn_t free_fn,
130 pcpu_fc_map_fn_t map_fn);
132 extern void *pcpu_lpage_remapped(void *kaddr);
134 static inline void *pcpu_lpage_remapped(void *kaddr)
141 * Use this to get to a cpu's version of the per-cpu object
142 * dynamically allocated. Non-atomic access to the current CPU's
143 * version should probably be combined with get_cpu()/put_cpu().
145 #define per_cpu_ptr(ptr, cpu) SHIFT_PERCPU_PTR((ptr), per_cpu_offset((cpu)))
147 extern void *__alloc_reserved_percpu(size_t size, size_t align);
149 #else /* CONFIG_HAVE_LEGACY_PER_CPU_AREA */
155 /* pointer disguising messes up the kmemleak objects tracking */
156 #ifndef CONFIG_DEBUG_KMEMLEAK
157 #define __percpu_disguise(pdata) (struct percpu_data *)~(unsigned long)(pdata)
159 #define __percpu_disguise(pdata) (struct percpu_data *)(pdata)
162 #define per_cpu_ptr(ptr, cpu) \
164 struct percpu_data *__p = __percpu_disguise(ptr); \
165 (__typeof__(ptr))__p->ptrs[(cpu)]; \
168 #endif /* CONFIG_HAVE_LEGACY_PER_CPU_AREA */
170 extern void *__alloc_percpu(size_t size, size_t align);
171 extern void free_percpu(void *__pdata);
173 #ifndef CONFIG_HAVE_SETUP_PER_CPU_AREA
174 extern void __init setup_per_cpu_areas(void);
177 #else /* CONFIG_SMP */
179 #define per_cpu_ptr(ptr, cpu) ({ (void)(cpu); (ptr); })
181 static inline void *__alloc_percpu(size_t size, size_t align)
184 * Can't easily make larger alignment work with kmalloc. WARN
185 * on it. Larger alignment should only be used for module
186 * percpu sections on SMP for which this path isn't used.
188 WARN_ON_ONCE(align > SMP_CACHE_BYTES);
189 return kzalloc(size, GFP_KERNEL);
192 static inline void free_percpu(void *p)
197 static inline void __init setup_per_cpu_areas(void) { }
199 static inline void *pcpu_lpage_remapped(void *kaddr)
204 #endif /* CONFIG_SMP */
206 #define alloc_percpu(type) (type *)__alloc_percpu(sizeof(type), \
210 * Optional methods for optimized non-lvalue per-cpu variable access.
212 * @var can be a percpu variable or a field of it and its size should
213 * equal char, int or long. percpu_read() evaluates to a lvalue and
214 * all others to void.
216 * These operations are guaranteed to be atomic w.r.t. preemption.
217 * The generic versions use plain get/put_cpu_var(). Archs are
218 * encouraged to implement single-instruction alternatives which don't
219 * require preemption protection.
222 # define percpu_read(var) \
224 typeof(per_cpu_var(var)) __tmp_var__; \
225 __tmp_var__ = get_cpu_var(var); \
231 #define __percpu_generic_to_op(var, val, op) \
233 get_cpu_var(var) op val; \
238 # define percpu_write(var, val) __percpu_generic_to_op(var, (val), =)
242 # define percpu_add(var, val) __percpu_generic_to_op(var, (val), +=)
246 # define percpu_sub(var, val) __percpu_generic_to_op(var, (val), -=)
250 # define percpu_and(var, val) __percpu_generic_to_op(var, (val), &=)
254 # define percpu_or(var, val) __percpu_generic_to_op(var, (val), |=)
258 # define percpu_xor(var, val) __percpu_generic_to_op(var, (val), ^=)
261 #endif /* __LINUX_PERCPU_H */