On Mon, Jan 21, 2013 at 09:42:55AM +0200, Hiroshi Doyu wrote: > Add API to detect SCU base address from CP15. > > Signed-off-by: Hiroshi Doyu <hdoyu@xxxxxxxxxx> > Acked-by: Santosh Shilimkar <santosh.shilimkar@xxxxxx> > --- > For usage: http://patchwork.ozlabs.org/patch/212013/ > --- > arch/arm/include/asm/smp_scu.h | 12 ++++++++++++ > 1 file changed, 12 insertions(+) > > diff --git a/arch/arm/include/asm/smp_scu.h b/arch/arm/include/asm/smp_scu.h > index 4eb6d00..1733ec7 100644 > --- a/arch/arm/include/asm/smp_scu.h > +++ b/arch/arm/include/asm/smp_scu.h > @@ -6,6 +6,18 @@ > #define SCU_PM_POWEROFF 3 > > #ifndef __ASSEMBLER__ > + > +#include <asm/cputype.h> > + > +static inline phys_addr_t scu_get_base(void) > +{ > + if (read_cpuid_part_number() == ARM_CPU_PART_CORTEX_A9) { > + phys_addr_t pa; > + asm("mrc p15, 4, %0, c15, c0, 0" : "=r" (pa)); > + return pa; > + } > + return 0; > +} > unsigned int scu_get_core_count(void __iomem *); > void scu_enable(void __iomem *); > int scu_power_mode(void __iomem *, unsigned int); Not sure what iteration this patch is at but... it's easy to avoid more iterations when you review the patch yourself before sending. Reasonable coding style suggests there should be a blank line after the new } and before the prototypes. However, as I _am_ commenting on this patch because of the above, I'll also suggest that we don't do it like this. And actually, the above code is buggy. If phys_addr_t is 64-bit, the upper half of 'pa' won't be set. I'd suggest this instead: static inline bool scu_a9_has_base(void) { return read_cpuid_part_number() == ARM_CPU_PART_CORTEX_A9; } static inline unsigned long scu_a9_get_base(void) { unsigned long pa; asm("mrc p15, 4, %0, c15, c0, 0" : "=r" (pa)); return pa; } and let the user of these functions decide whether to read it using scu_a9_has_base(). And why 'unsigned long' ? Well, it could also be u32, but on 32-bit ARM, it's been more conventional to use unsigned long for phys addresses which can't be larger than 32-bit - which this one can't because the mrc instruction is limited to writing one 32-bit register. -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
