Hi Vineet, > From: Vineet Gupta <vgupta@xxxxxxxxxxxx> > Sent: Tuesday, April 28, 2020 22:46 > To: Eugeniy Paltsev; linux-snps-arc@xxxxxxxxxxxxxxxxxxx > Cc: Alexey Brodkin; linux-kernel@xxxxxxxxxxxxxxx > Subject: Re: [PATCH] ARC: guard dsp early init against non ARCv2 > > On 4/28/20 11:50 AM, Eugeniy Paltsev wrote: > > As of today we guard early DSP init code with > > ARC_AUX_DSP_BUILD (0x7A) BCR check to verify that we have > > CPU with DSP configured. However that's not enough as in > > ARCv1 CPU the same BCR (0x7A) is used for checking MUL/MAC > > instructions presence. > > > > So, let's guard DSP early init against non ARCv2. > > > > Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@xxxxxxxxxxxx> > > --- > > arch/arc/include/asm/dsp-impl.h | 2 ++ > > 1 file changed, 2 insertions(+) > > > > diff --git a/arch/arc/include/asm/dsp-impl.h b/arch/arc/include/asm/dsp-impl.h > > index e1aa212ca6eb..e64d945ae7df 100644 > > --- a/arch/arc/include/asm/dsp-impl.h > > +++ b/arch/arc/include/asm/dsp-impl.h > > @@ -15,12 +15,14 @@ > > > > /* clobbers r5 register */ > > .macro DSP_EARLY_INIT > > +#if defined(CONFIG_ISA_ARCV2) > > ifdef is the canonical way for a single macro to check. > > Also, this needs to be finer grained, i.e. CONFIG_ARC_DSP_KERNEL which is already > tied to ARCV2 only configs. We shouldn't limit the scope of this code part [dsp early init] to the cases were DSP support is enabled in kconfig - and that is the reason why this code initially was guarded with BCR check only. So, I change the check to #if defined(CONFIG_ARC_DSP_HANDLED) || defined(CONFIG_ARC_DSP_NONE) which is actually the equivalent to #if defined(CONFIG_ISA_ARCV2) but I don't think it's worth thing to do. > > > lr r5, [ARC_AUX_DSP_BUILD] > > bmsk r5, r5, 7 > > breq r5, 0, 1f > > mov r5, DSP_CTRL_DISABLED_ALL > > sr r5, [ARC_AUX_DSP_CTRL] > > 1: > > +#endif > > .endm > > > > /* clobbers r10, r11 registers pair */ --- Eugeniy Paltsev _______________________________________________ linux-snps-arc mailing list linux-snps-arc@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/linux-snps-arc
