On Thu, Nov 24, 2016 at 01:40:05PM +0000, Suzuki K Poulose wrote: > Define helper macros to extract op0, op1, CRn, CRm & op2 > for a given sys_reg id. > > Cc: Catalin Marinas <catalin.mari...@arm.com> > Cc: Mark Rutland <mark.rutl...@arm.com> > Cc: Will Deacon <will.dea...@arm.com> > Signed-off-by: Suzuki K Poulose <suzuki.poul...@arm.com> > --- > arch/arm64/include/asm/sysreg.h | 21 ++++++++++++++++++++- > 1 file changed, 20 insertions(+), 1 deletion(-) > > diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h > index 6c80b36..488b939 100644 > --- a/arch/arm64/include/asm/sysreg.h > +++ b/arch/arm64/include/asm/sysreg.h > @@ -34,8 +34,27 @@ > * [11-8] : CRm > * [7-5] : Op2 > */ > +#define Op0_shift 19 > +#define Op0_mask 0x3 > +#define Op1_shift 16 > +#define Op1_mask 0x7 > +#define CRn_shift 12 > +#define CRn_mask 0xf > +#define CRm_shift 8 > +#define CRm_mask 0xf > +#define Op2_shift 5 > +#define Op2_mask 0x7 > + > #define sys_reg(op0, op1, crn, crm, op2) \ > - ((((op0)&3)<<19)|((op1)<<16)|((crn)<<12)|((crm)<<8)|((op2)<<5)) > + ((((op0) & Op0_mask) << Op0_shift) | \ > + ((op1) << Op1_shift) | ((crn) << CRn_shift) | \ > + ((crm) << CRm_shift) | ((op2) << Op2_shift))
You're preserving the current behaviour here, but why do we care so much about masking op0 but then not bother masking any of the other fields? Will
