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| author | Christoph Lameter <cl@linux.com> | 2010-12-06 11:39:59 -0600 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2010-12-17 15:15:28 +0100 |
| commit | a663ffff1d2e94a7c549a37d08ed9169ce83bdd6 (patch) | |
| tree | b33e87a2b1051b8ae57eb39cd147122c59da9189 /include/linux/percpu.h | |
| parent | a3383e8372c0c11238f9bb9777929bfc3a2d320a (diff) | |
| download | lwn-a663ffff1d2e94a7c549a37d08ed9169ce83bdd6.tar.gz lwn-a663ffff1d2e94a7c549a37d08ed9169ce83bdd6.zip | |
percpu: Generic support for this_cpu_add, sub, dec, inc_return
Introduce generic support for this_cpu_add_return etc.
The fallback is to realize these operations with simpler __this_cpu_ops.
tj: - Reformatted __cpu_size_call_return2() to make it more consistent
with its neighbors.
- Dropped unnecessary temp variable ret__ from
__this_cpu_generic_add_return().
Reviewed-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'include/linux/percpu.h')
| -rw-r--r-- | include/linux/percpu.h | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/include/linux/percpu.h b/include/linux/percpu.h index 5095b834a6fb..4d593defc47d 100644 --- a/include/linux/percpu.h +++ b/include/linux/percpu.h @@ -240,6 +240,21 @@ extern void __bad_size_call_parameter(void); pscr_ret__; \ }) +#define __pcpu_size_call_return2(stem, variable, ...) \ +({ \ + typeof(variable) pscr2_ret__; \ + __verify_pcpu_ptr(&(variable)); \ + switch(sizeof(variable)) { \ + case 1: pscr2_ret__ = stem##1(variable, __VA_ARGS__); break; \ + case 2: pscr2_ret__ = stem##2(variable, __VA_ARGS__); break; \ + case 4: pscr2_ret__ = stem##4(variable, __VA_ARGS__); break; \ + case 8: pscr2_ret__ = stem##8(variable, __VA_ARGS__); break; \ + default: \ + __bad_size_call_parameter(); break; \ + } \ + pscr2_ret__; \ +}) + #define __pcpu_size_call(stem, variable, ...) \ do { \ __verify_pcpu_ptr(&(variable)); \ @@ -529,6 +544,62 @@ do { \ # define __this_cpu_xor(pcp, val) __pcpu_size_call(__this_cpu_xor_, (pcp), (val)) #endif +#define _this_cpu_generic_add_return(pcp, val) \ +({ \ + typeof(pcp) ret__; \ + preempt_disable(); \ + __this_cpu_add(pcp, val); \ + ret__ = __this_cpu_read(pcp); \ + preempt_enable(); \ + ret__; \ +}) + +#ifndef this_cpu_add_return +# ifndef this_cpu_add_return_1 +# define this_cpu_add_return_1(pcp, val) _this_cpu_generic_add_return(pcp, val) +# endif +# ifndef this_cpu_add_return_2 +# define this_cpu_add_return_2(pcp, val) _this_cpu_generic_add_return(pcp, val) +# endif +# ifndef this_cpu_add_return_4 +# define this_cpu_add_return_4(pcp, val) _this_cpu_generic_add_return(pcp, val) +# endif +# ifndef this_cpu_add_return_8 +# define this_cpu_add_return_8(pcp, val) _this_cpu_generic_add_return(pcp, val) +# endif +# define this_cpu_add_return(pcp, val) __pcpu_size_call_return2(this_cpu_add_return_, pcp, val) +#endif + +#define this_cpu_sub_return(pcp, val) this_cpu_add_return(pcp, -(val)) +#define this_cpu_inc_return(pcp) this_cpu_add_return(pcp, 1) +#define this_cpu_dec_return(pcp) this_cpu_add_return(pcp, -1) + +#define __this_cpu_generic_add_return(pcp, val) \ +({ \ + __this_cpu_add(pcp, val); \ + __this_cpu_read(pcp); \ +}) + +#ifndef __this_cpu_add_return +# ifndef __this_cpu_add_return_1 +# define __this_cpu_add_return_1(pcp, val) __this_cpu_generic_add_return(pcp, val) +# endif +# ifndef __this_cpu_add_return_2 +# define __this_cpu_add_return_2(pcp, val) __this_cpu_generic_add_return(pcp, val) +# endif +# ifndef __this_cpu_add_return_4 +# define __this_cpu_add_return_4(pcp, val) __this_cpu_generic_add_return(pcp, val) +# endif +# ifndef __this_cpu_add_return_8 +# define __this_cpu_add_return_8(pcp, val) __this_cpu_generic_add_return(pcp, val) +# endif +# define __this_cpu_add_return(pcp, val) __pcpu_size_call_return2(this_cpu_add_return_, pcp, val) +#endif + +#define __this_cpu_sub_return(pcp, val) this_cpu_add_return(pcp, -(val)) +#define __this_cpu_inc_return(pcp) this_cpu_add_return(pcp, 1) +#define __this_cpu_dec_return(pcp) this_cpu_add_return(pcp, -1) + /* * IRQ safe versions of the per cpu RMW operations. Note that these operations * are *not* safe against modification of the same variable from another |