xref: /linux/include/asm-generic/local.h (revision de2fe5e07d58424bc286fff3fd3c1b0bf933cd58)
1 #ifndef _ASM_GENERIC_LOCAL_H
2 #define _ASM_GENERIC_LOCAL_H
3 
4 #include <linux/config.h>
5 #include <linux/percpu.h>
6 #include <linux/hardirq.h>
7 #include <asm/atomic.h>
8 #include <asm/types.h>
9 
10 /* An unsigned long type for operations which are atomic for a single
11  * CPU.  Usually used in combination with per-cpu variables. */
12 
13 /* Implement in terms of atomics. */
14 
15 /* Don't use typedef: don't want them to be mixed with atomic_t's. */
16 typedef struct
17 {
18 	atomic_long_t a;
19 } local_t;
20 
21 #define LOCAL_INIT(i)	{ ATOMIC_LONG_INIT(i) }
22 
23 #define local_read(l)	((unsigned long)atomic_long_read(&(l)->a))
24 #define local_set(l,i)	atomic_long_set((&(l)->a),(i))
25 #define local_inc(l)	atomic_long_inc(&(l)->a)
26 #define local_dec(l)	atomic_long_dec(&(l)->a)
27 #define local_add(i,l)	atomic_long_add((i),(&(l)->a))
28 #define local_sub(i,l)	atomic_long_sub((i),(&(l)->a))
29 
30 /* Non-atomic variants, ie. preemption disabled and won't be touched
31  * in interrupt, etc.  Some archs can optimize this case well. */
32 #define __local_inc(l)		local_set((l), local_read(l) + 1)
33 #define __local_dec(l)		local_set((l), local_read(l) - 1)
34 #define __local_add(i,l)	local_set((l), local_read(l) + (i))
35 #define __local_sub(i,l)	local_set((l), local_read(l) - (i))
36 
37 /* Use these for per-cpu local_t variables: on some archs they are
38  * much more efficient than these naive implementations.  Note they take
39  * a variable (eg. mystruct.foo), not an address.
40  */
41 #define cpu_local_read(v)	local_read(&__get_cpu_var(v))
42 #define cpu_local_set(v, i)	local_set(&__get_cpu_var(v), (i))
43 #define cpu_local_inc(v)	local_inc(&__get_cpu_var(v))
44 #define cpu_local_dec(v)	local_dec(&__get_cpu_var(v))
45 #define cpu_local_add(i, v)	local_add((i), &__get_cpu_var(v))
46 #define cpu_local_sub(i, v)	local_sub((i), &__get_cpu_var(v))
47 
48 /* Non-atomic increments, ie. preemption disabled and won't be touched
49  * in interrupt, etc.  Some archs can optimize this case well.
50  */
51 #define __cpu_local_inc(v)	__local_inc(&__get_cpu_var(v))
52 #define __cpu_local_dec(v)	__local_dec(&__get_cpu_var(v))
53 #define __cpu_local_add(i, v)	__local_add((i), &__get_cpu_var(v))
54 #define __cpu_local_sub(i, v)	__local_sub((i), &__get_cpu_var(v))
55 
56 #endif /* _ASM_GENERIC_LOCAL_H */
57