Provide arch code to create the (local atomic) instructions. Signed-off-by: Christoph Lameter --- include/linux/percpu.h | 179 ++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 178 insertions(+), 1 deletion(-) Index: linux-2.6/include/linux/percpu.h =================================================================== --- linux-2.6.orig/include/linux/percpu.h 2010-11-23 16:49:02.000000000 -0600 +++ linux-2.6/include/linux/percpu.h 2010-11-23 16:50:45.000000000 -0600 @@ -254,6 +254,21 @@ extern void __bad_size_call_parameter(vo pscr_ret__; \ }) +/* Special handling for cmpxchg_double */ +#define __pcpu_size_call_return_int(stem, pcp, ...) \ +({ int pscr_ret__; \ + __verify_pcpu_ptr(pcp); \ + switch(sizeof(*pcp)) { \ + case 1: pscr_ret__ = stem##1(pcp, __VA_ARGS__);break; \ + case 2: pscr_ret__ = stem##2(pcp, __VA_ARGS__);break; \ + case 4: pscr_ret__ = stem##4(pcp, __VA_ARGS__);break; \ + case 8: pscr_ret__ = stem##8(pcp, __VA_ARGS__);break; \ + default: \ + __bad_size_call_parameter();break; \ + } \ + pscr_ret__; \ +}) + #define __pcpu_size_call(stem, variable, ...) \ do { \ __verify_pcpu_ptr(&(variable)); \ @@ -599,6 +614,134 @@ do { \ #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_cmpxchg(pcp, oval, nval) \ +({ typeof(pcp) ret__; \ + preempt_disable(); \ + ret__ = __this_cpu_read(pcp); \ + if (ret__ == (oval)) \ + __this_cpu_write(pcp, nval); \ + preempt_enable(); \ + ret__; \ +}) + +#ifndef this_cpu_cmpxchg +# ifndef this_cpu_cmpxchg_1 +# define this_cpu_cmpxchg_1(pcp, oval, nval) _this_cpu_generic_cmpxchg(pcp, oval, nval) +# endif +# ifndef this_cpu_cmpxchg_2 +# define this_cpu_cmpxchg_2(pcp, oval, nval) _this_cpu_generic_cmpxchg(pcp, oval, nval) +# endif +# ifndef this_cpu_cmpxchg_4 +# define this_cpu_cmpxchg_4(pcp, oval, nval) _this_cpu_generic_cmpxchg(pcp, oval, nval) +# endif +# ifndef this_cpu_cmpxchg_8 +# define this_cpu_cmpxchg_8(pcp, oval, nval) _this_cpu_generic_cmpxchg(pcp, oval, nval) +# endif +# define this_cpu_cmpxchg(pcp, oval, nval) __pcpu_size_call_return2(this_cpu_cmpxchg_, (pcp), oval, nval) +#endif + +#define __this_cpu_generic_cmpxchg(pcp, oval, nval) \ +({ typeof(pcp) ret__; \ + ret__ = __this_cpu_read(pcp); \ + if (ret__ == (oval)) \ + __this_cpu_write(pcp, nval); \ + ret__; \ +}) + +#ifndef __this_cpu_cmpxchg +# ifndef __this_cpu_cmpxchg_1 +# define __this_cpu_cmpxchg_1(pcp, oval, nval) __this_cpu_generic_cmpxchg(pcp, oval, nval) +# endif +# ifndef __this_cpu_cmpxchg_2 +# define __this_cpu_cmpxchg_2(pcp, oval, nval) __this_cpu_generic_cmpxchg(pcp, oval, nval) +# endif +# ifndef __this_cpu_cmpxchg_4 +# define __this_cpu_cmpxchg_4(pcp, oval, nval) __this_cpu_generic_cmpxchg(pcp, oval, nval) +# endif +# ifndef __this_cpu_cmpxchg_8 +# define __this_cpu_cmpxchg_8(pcp, oval, nval) __this_cpu_generic_cmpxchg(pcp, oval, nval) +# endif +# define __this_cpu_cmpxchg(pcp, oval, nval) __pcpu_size_call_return2(\ + __this_cpu_cmpxchg_, (pcp), oval, nval) +#endif + +/* + * cmpxchg_double replaces two adjacent scalars at once. The first parameter + * passed is a percpu pointer, not a scalar like the other this_cpu + * operations. This is so because the function operates on two scalars + * (must be of same size). A truth value is returned to indicate success or + * failure (since a double register result is difficult to handle). + * There is very limited hardware support for these operations. So only certain + * sizes may work. + */ +#define __this_cpu_generic_cmpxchg_double(pcp, oval1, oval2, nval1, nval2) \ +({ typeof(oval2) * __percpu pcp2 = (typeof(oval2) *)((pcp) + 1); \ + int __ret = 0; \ + if (__this_cpu_read(*pcp) == (oval1) && \ + __this_cpu_read(*pcp2) == (oval2)) { \ + __this_cpu_write(*pcp, (nval1)); \ + __this_cpu_write(*pcp2, (nval2)); \ + __ret = 1; \ + } \ + (__ret); \ +}) + +#ifndef __this_cpu_cmpxchg_double +# ifndef __this_cpu_cmpxchg_double_1 +# define __this_cpu_cmpxchg_double_1(pcp, oval1, oval2, nval1, nval2) \ + __this_cpu_generic_cmpxchg_double(pcp, oval1, oval2, nval1, nval2) +# endif +# ifndef __this_cpu_cmpxchg_double_2 +# define __this_cpu_cmpxchg_double_2(pcp, oval1, oval2, nval1, nval2) \ + __this_cpu_generic_cmpxchg_double(pcp, oval1, oval2, nval1, nval2) +# endif +# ifndef __this_cpu_cmpxchg_double_4 +# define __this_cpu_cmpxchg_double_4(pcp, oval1, oval2, nval1, nval2) \ + __this_cpu_generic_cmpxchg_double(pcp, oval1, oval2, nval1, nval2) +# endif +# ifndef __this_cpu_cmpxchg_double_8 +# define __this_cpu_cmpxchg_double_8(pcp, oval1, oval2, nval1, nval2) \ + __this_cpu_generic_cmpxchg_double(pcp, oval1, oval2, nval1, nval2) +# endif +# define __this_cpu_cmpxchg_double(pcp, oval1, oval2, nval1, nval2) \ + __pcpu_size_call_return_int(__this_cpu_cmpxchg_double_, (pcp), \ + oval1, oval2, nval1, nval2) +#endif + +#define _this_cpu_generic_cmpxchg_double(pcp, oval1, oval2, nval1, nval2) \ +({ int ret__; \ + preempt_disable(); \ + ret__ = __this_cpu_generic_cmpxchg_double(pcp, \ + oval1, oval2, nval1, nval2); \ + preempt_enable(); \ + ret__; \ +}) + +#ifndef this_cpu_cmpxchg_double +# ifndef this_cpu_cmpxchg_double_1 +# define this_cpu_cmpxchg_double_1(pcp, oval1, oval2, nval1, nval2) \ + _this_cpu_generic_cmpxchg_double(pcp, oval1, oval2, nval1, nval2) +# endif +# ifndef this_cpu_cmpxchg_double_2 +# define this_cpu_cmpxchg_double_2(pcp, oval1, oval2, nval1, nval2) \ + _this_cpu_generic_cmpxchg_double(pcp, oval1, oval2, nval1, nval2) +# endif +# ifndef this_cpu_cmpxchg_double_4 +# define this_cpu_cmpxchg_double_4(pcp, oval1, oval2, nval1, nval2) \ + _this_cpu_generic_cmpxchg_double(pcp, oval1, oval2, nval1, nval2) +# endif +# ifndef this_cpu_cmpxchg_double_8 +# define this_cpu_cmpxchg_double_8(pcp, oval1, oval2, nval1, nval2) \ + _this_cpu_generic_cmpxchg_double(pcp, oval1, oval2, nval1, nval2) +# endif +# define this_cpu_cmpxchg_double(pcp, oval1, oval2, nval1, nval2) \ + __pcpu_size_call_return_int(this_cpu_cmpxchg_double_, (pcp), \ + oval1, oval2, nval1, nval2) +#endif + + + + #define _this_cpu_generic_to_op(pcp, val, op) \ do { \ preempt_disable(); \ @@ -610,7 +753,7 @@ do { \ * IRQ safe versions of the per cpu RMW operations. Note that these operations * are *not* safe against modification of the same variable from another * processors (which one gets when using regular atomic operations) - . They are guaranteed to be atomic vs. local interrupts and + * They are guaranteed to be atomic vs. local interrupts and * preemption only. */ #define irqsafe_cpu_generic_to_op(pcp, val, op) \ @@ -697,4 +840,38 @@ do { \ # define irqsafe_cpu_xor(pcp, val) __pcpu_size_call(irqsafe_cpu_xor_, (val)) #endif +#define irqsafe_generic_cmpxchg_double(pcp, oval1, oval2, nval1, nval2) \ +({ int ret__; \ + unsigned long flags; \ + local_irq_save(flags); \ + ret__ = __this_cpu_generic_cmpxchg_double(pcp, \ + oval1, oval2, nval1, nval2); \ + local_irq_restore(flags); \ + ret__; \ +}) + +#ifndef irqsafe_cmpxchg_double +# ifndef irqsafe_cmpxchg_double_1 +# define irqsafe_cmpxchg_double_1(pcp, oval1, oval2, nval1, nval2) \ + irqsafe_generic_cmpxchg_double(pcp, oval1, oval2, nval1, nval2) +# endif +# ifndef irqsafe_cmpxchg_double_2 +# define irqsafe_cmpxchg_double_2(pcp, oval1, oval2, nval1, nval2) \ + irqsafe_generic_cmpxchg_double(pcp, oval1, oval2, nval1, nval2) +# endif +# ifndef irqsafe_cmpxchg_double_4 +# define irqsafe_cmpxchg_double_4(pcp, oval1, oval2, nval1, nval2) \ + irqsafe_generic_cmpxchg_double(pcp, oval1, oval2, nval1, nval2) +# endif +# ifndef irqsafe_cmpxchg_double_8 +# define irqsafe_cmpxchg_double_8(pcp, oval1, oval2, nval1, nval2) \ + irqsafe_generic_cmpxchg_double(pcp, oval1, oval2, nval1, nval2) +# endif +# define irqsafe_cmpxchg_double(pcp, oval1, oval2, nval1, nval2) \ + __pcpu_size_call_return_int(irqsafe_cmpxchg_double_, (pcp), \ + oval1, oval2, nval1, nval2) +#endif + + + #endif /* __LINUX_PERCPU_H */ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/