[OpenBIOS] [PATCH] ppc: Use mtmsrd on ppc64

[Alexander Graf]

On 16.11.2010, at 00:30, Andreas Färber wrote:

> Am 16.11.2010 um 00:27 schrieb Alexander Graf:
> 
>> On 16.11.2010, at 00:25, Andreas Färber wrote:
>> 
>>> Cc: Alexander Graf <agraf at suse.de>
>>> Signed-off-by: Andreas Färber <andreas.faerber at web.de>
>>> ---
>>> arch/ppc/qemu/ofmem.c |    8 +++++++-
>>> 1 files changed, 7 insertions(+), 1 deletions(-)
>>> 
>>> diff --git a/arch/ppc/qemu/ofmem.c b/arch/ppc/qemu/ofmem.c
>>> index 9c60841..e8b0b24 100644
>>> --- a/arch/ppc/qemu/ofmem.c
>>> +++ b/arch/ppc/qemu/ofmem.c
>>> @@ -25,6 +25,12 @@
>>> 
>>> #define BIT(n)		(1U<<(31-(n)))
>>> 
>>> +#ifdef __powerpc64__
>>> +#define MTMSR "mtmsrd"
>>> +#else
>>> +#define MTMSR "mtmsr"
>>> +#endif
>>> +
>>> /* called from assembly */
>>> extern void dsi_exception( void );
>>> extern void isi_exception( void );
>>> @@ -417,7 +423,7 @@ setup_mmu( unsigned long ramsize )
>>> 
>>> 	asm volatile("mfmsr %0" : "=r" (msr) : );
>>> 	msr |= MSR_IR | MSR_DR;
>>> -	asm volatile("mtmsr %0" :: "r" (msr) );
>>> +	asm volatile(MTMSR " %0" :: "r" (msr) );
>> 
>> Is that the only occurence of mtmsr in all the code? Better replace all at once or you'll be chasing bugs later on :).
> 
> The only one in inline assembler. The question would be how to go about turning this into a header-capable macro. For simplicity I defined it as a string literal here, doesn't work for real assembler obviously.

Real assembler needs a different define. I'd again suggest to stick to Linux nomenclatures:

#ifdef CONFIG_PPC_BOOK3S_64
#define RFI             rfid
#define MTMSRD(r)       mtmsrd  r
#else
#define RFI             rfi
#define MTMSRD(r)       mtmsr   r
#endif

For C, please go with something like

static inline unsigned long mfmsr(void)
{
    unsigned long msr;
    asm volatile("mfmsr %0" : "=r" (msr) : );
    return msr;
}

static inline void mtmsr(unsigned long msr)
{
#ifdef __powerpc64__
    asm volatile("mtmsrd %0" :: "r" (msr) : );
#else
    asm volatile("mtmsr %0" :: "r" (msr) : );
#endif
    return msr;
}

in a globally defined place and use that:

mtmsr(mfmsr() | MSR_IR | MSR_DR);


Alex