Dave, > -----Original Message----- > From: Dave Martin [mailto:dave.martin@xxxxxxxxxx] > Sent: Friday, February 04, 2011 7:51 PM > To: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx > Cc: Dave Martin; Tony Lindgren; Santosh Shilimkar; Jean Pihet; > linux-omap@xxxxxxxxxxxxxxx; Nicolas Pitre; Russell King > Subject: [PATCH] ARM: Define wfi(), wfe(), sev() macros for pre-v7 > processors > > Pre-v7 processors don't have wfe/sev, so these are defined for > consistency as empty barrier asms. > > For v6, wfi is architected as a defined MCR instruction, so > use that definition. > > Doing a no-op instead of wfi() is probably bad, so for older > processors than v6, wfi() is not defined. If needed, some CPU- > specific wfi() will have to be defined elsewhere. > > Signed-off-by: Dave Martin <dave.martin@xxxxxxxxxx> > --- > arch/arm/include/asm/system.h | 7 +++++++ > 1 files changed, 7 insertions(+), 0 deletions(-) > > diff --git a/arch/arm/include/asm/system.h > b/arch/arm/include/asm/system.h > index 97f6d60..0e1cae3 100644 > --- a/arch/arm/include/asm/system.h > +++ b/arch/arm/include/asm/system.h > @@ -129,7 +129,14 @@ extern unsigned int user_debug; > #define sev() __asm__ __volatile__ ("sev" : : : "memory") > #define wfe() __asm__ __volatile__ ("wfe" : : : "memory") > #define wfi() __asm__ __volatile__ ("wfi" : : : "memory") > +#else /* __LINUX_ARM_ARCH__ < 7 */ > +#define sev() __asm__ __volatile__ ("" : : : "memory") > +#define wfe() __asm__ __volatile__ ("" : : : "memory") This is not true for "CPU_32v6K" extensions, right. I think they do support 'sev' and 'wfe' instructions. > +#if __LINUX_ARM_ARCH__ == 6 > +#define wfi() __asm__ __volatile__ ("mcr p15, 0, %0, c7, c5, 4" > \ > + : : "r" (0) : "memory") > #endif > +#endif /* __LINUX_ARM_ARCH__ < 7 */ > > #if __LINUX_ARM_ARCH__ >= 7 > #define isb() __asm__ __volatile__ ("isb" : : : "memory") > -- > 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
