[Skiboot] [RFC PATCH] Use macros rather than static inline for mfspr and mtspr

[Balbir Singh]

On Wed, Jul 13, 2016 at 4:20 PM, Stewart Smith
<stewart at linux.vnet.ibm.com> wrote:
> Fixes building skiboot without optimization.
>
> Signed-off-by: Stewart Smith <stewart at linux.vnet.ibm.com>
> ---
>  include/processor.h | 27 +++++++++++++++------------
>  1 file changed, 15 insertions(+), 12 deletions(-)
>
> diff --git a/include/processor.h b/include/processor.h
> index 48bbf903df58..76ddf2ee4802 100644
> --- a/include/processor.h
> +++ b/include/processor.h
> @@ -18,6 +18,9 @@
>  #define __PROCESSOR_H
>
>  #include <bitutils.h>
> +#ifndef __ASSEMBLY__
> +#include <ccan/str/str.h>
> +#endif
>
>  /* P7 MSR bits */
>  #define MSR_SF         PPC_BIT(0)      /* 64-bit mode */
> @@ -235,18 +238,18 @@ static inline void mtmsrd(unsigned long val, int l)
>         asm volatile("mtmsrd %0,%1" : : "r"(val), "i"(l) : "memory");
>  }
>
> -static inline unsigned long mfspr(unsigned int spr)
> -{
> -       unsigned long val;
> -
> -       asm volatile("mfspr %0,%1" : "=r"(val) : "i"(spr) : "memory");
> -       return val;
> -}
> -
> -static inline void mtspr(unsigned int spr, unsigned long val)
> -{
> -       asm volatile("mtspr %0,%1" : : "i"(spr), "r"(val) : "memory");
> -}
> +#define mfspr(spr) ( \
> +{ \
> +       unsigned long val; \
> +\
> +       asm volatile("mfspr %0," stringify(spr) : "=r"(val) : : "memory"); \
> +       val; \
> +})
> +
> +#define mtspr(spr, val) (\
> +{ \
> +       asm volatile("mtspr " stringify(spr) ",%0" : : "r"(val) : "memory"); \
> +})
>
>  /* Helpers for special sequences needed by some registers */
>  extern void set_hid0(unsigned long hid0);


Are you suggesting that inline is ignored by gcc without -O2? Have you
considered __attribute__((always_inline))?

Balbir Singh