On 4/29/20 10:12 AM, Eugeniy Paltsev wrote: > 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) You are right. It needs to be disabled if the hardware exists independent of Kconfig. > which is actually the equivalent to > > #if defined(CONFIG_ISA_ARCV2) > > but I don't think it's worth thing to do. Agree. -Vineet _______________________________________________ linux-snps-arc mailing list linux-snps-arc@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/linux-snps-arc
