Re: [Qemu-devel] [kvm-unit-tests PATCH v13 1/4] arm: Define macros for accessing system registers

[Andrew Jones]

On Thu, Dec 01, 2016 at 09:27:59AM -0600, Wei Huang wrote:
> 
> 
> On 12/01/2016 02:59 AM, Andrew Jones wrote:
> > 
> > Should this be From: Andre?
> > 
> > On Wed, Nov 30, 2016 at 11:16:39PM -0600, Wei Huang wrote:
> >> This patch defines four macros to assist creating system register
> >> accessors under both ARMv7 and AArch64:
> >>    * DEFINE_GET_SYSREG32(name, ...)
> >>    * DEFINE_SET_SYSREG32(name, ...)
> >>    * DEFINE_GET_SYSREG64(name, ...)
> >>    * DEFINE_SET_SYSREG64(name, ...)
> >> These macros are translated to inline functions with consistent naming,
> >> get_##name() and set_##name(), which can be used by C code directly.
> >>
> >> Signed-off-by: Andre Przywara <address@hidden>
> >> Signed-off-by: Wei Huang <address@hidden>
> >> ---
> >>  lib/arm/asm/processor.h   | 37 ++++++++++++++++++++++++++++++++-----
> >>  lib/arm64/asm/processor.h | 35 ++++++++++++++++++++++++++++-------
> >>  2 files changed, 60 insertions(+), 12 deletions(-)
> >>
> >> diff --git a/lib/arm/asm/processor.h b/lib/arm/asm/processor.h
> >> index f25e7ee..3ca6b42 100644
> >> --- a/lib/arm/asm/processor.h
> >> +++ b/lib/arm/asm/processor.h
> >> @@ -33,13 +33,40 @@ static inline unsigned long current_cpsr(void)
> >>  
> >>  #define current_mode() (current_cpsr() & MODE_MASK)
> >>  
> >> -static inline unsigned int get_mpidr(void)
> >> -{
> >> -  unsigned int mpidr;
> >> -  asm volatile("mrc p15, 0, %0, c0, c0, 5" : "=r" (mpidr));
> >> -  return mpidr;
> >> +#define DEFINE_GET_SYSREG32(name, opc1, crn, crm, opc2)                   
> >> \
> >> +static inline uint32_t get_##name(void)                                   
> >> \
> >> +{                                                                 \
> >> +  uint32_t reg;                                                   \
> >> +  asm volatile("mrc p15, " #opc1 ", %0, " #crn ", " #crm ", "     \
> >> +               #opc2 : "=r" (reg));                               \
> >> +  return reg;                                                     \
> >> +}
> >> +
> >> +#define DEFINE_SET_SYSREG32(name, opc1, crn, crm, opc2)                   
> >> \
> >> +static inline void set_##name(uint32_t value)                             
> >> \
> >> +{                                                                 \
> >> +  asm volatile("mcr p15, " #opc1 ", %0, " #crn ", " #crm ", "     \
> >> +               #opc2 :: "r" (value));                             \
> >                            ^ nit: no space here, checkpatch would complain
> 
> Which checkpatch script you are using? I didn't find one in
> kvm-unit-tests. I tried kernel's checkpatch script, but it didn't
> complain anything against this patch.

I use the kernel's, and it, at least used to, complains about no
spaces between the ':' in asms. If it doesn't complain now, then
it doesn't matter. Actually, it didn't really matter before :-)

Thanks,
drew
> 
> >> +}
> >> +
> 
> <snip>
>