On Sun, May 17, 2020 at 8:29 AM Brian Gerst wrote:
>
> In preparation for cleaning up the percpu operations, define macros for
> abstraction based on the width of the operation.
>
> Signed-off-by: Brian Gerst
> ---
> arch/x86/include/asm/percpu.h | 30 ++
> 1 file changed, 30 insertions(+)
>
> diff --git a/arch/x86/include/asm/percpu.h b/arch/x86/include/asm/percpu.h
> index 2278797c769d..89f918a3e99b 100644
> --- a/arch/x86/include/asm/percpu.h
> +++ b/arch/x86/include/asm/percpu.h
> @@ -87,6 +87,36 @@
> * don't give an lvalue though). */
> extern void __bad_percpu_size(void);
>
> +#define __pcpu_type_1 u8
> +#define __pcpu_type_2 u16
> +#define __pcpu_type_4 u32
> +#define __pcpu_type_8 u64
> +
> +#define __pcpu_cast_1(val) ((u8)((unsigned long) val))
> +#define __pcpu_cast_2(val) ((u16)((unsigned long) val))
> +#define __pcpu_cast_4(val) ((u32)((unsigned long) val))
> +#define __pcpu_cast_8(val) ((u64)(val))
> +
> +#define __pcpu_op1_1(op, dst) op "b " dst
> +#define __pcpu_op1_2(op, dst) op "w " dst
> +#define __pcpu_op1_4(op, dst) op "l " dst
> +#define __pcpu_op1_8(op, dst) op "q " dst
> +
> +#define __pcpu_op2_1(op, src, dst) op "b " src ", " dst
> +#define __pcpu_op2_2(op, src, dst) op "w " src ", " dst
> +#define __pcpu_op2_4(op, src, dst) op "l " src ", " dst
> +#define __pcpu_op2_8(op, src, dst) op "q " src ", " dst
`op1` and `op2` aren't the most descriptive, though we kind of would
like terseness here. I guess "op1"s have 1 operand, and "op2"s have 2
operands.
> +
> +#define __pcpu_reg_1(out, x) out "q" (x)
> +#define __pcpu_reg_2(out, x) out "r" (x)
> +#define __pcpu_reg_4(out, x) out "r" (x)
> +#define __pcpu_reg_8(out, x) out "r" (x)
I think `mod` is more descriptive than `out`, as there are modifiers.
https://gcc.gnu.org/onlinedocs/gcc/Modifiers.html#Modifiers
I don't want to bikeshed, since the naming changes potentially mean
touching each patch. Just food for thought in case other reviewers
agree/disagree. So I'll just add:
Reviewed-by: Nick Desaulniers
> +
> +#define __pcpu_reg_imm_1(x) "qi" (x)
> +#define __pcpu_reg_imm_2(x) "ri" (x)
> +#define __pcpu_reg_imm_4(x) "ri" (x)
> +#define __pcpu_reg_imm_8(x) "re" (x)
> +
> #define percpu_to_op(qual, op, var, val) \
> do { \
> typedef typeof(var) pto_T__;\
> --
> 2.25.4
>
--
Thanks,
~Nick Desaulniers
