Re: [PATCH 2/4] ARM: nommu: dynamic exception base address setting

From: Afzal Mohammed
Date: Fri Jan 20 2017 - 11:20:42 EST


Hi,

On Thu, Jan 19, 2017 at 01:59:09PM +0000, Vladimir Murzin wrote:
> On 18/01/17 20:38, afzal mohammed wrote:

> > +#define ID_PFR1_SE (0x3 << 4) /* Security extension enable bits */
>
> This bitfiled is 4 bits wide.

Since only 2 LSb's out of the 4 were enough to detect whether security
extensions were enabled, it was done so. i am going to use your below
suggestion & this would be taken care by that.

> > + if (security_extensions_enabled()) {
>
> You can use
>
> cpuid_feature_extract(CPUID_EXT_PFR1, 4)
>
> and add a comment explaining what we are looking for and why.

Yes, that is better, was not aware of this, did saw CPUID_EXT_PFR1 as
an unused macro.

> > +#ifdef CONFIG_CPU_CP15
> > + vectors_base = setup_vectors_base();
> > +#endif
>
> alternatively it can be
>
> unsigned long vector_base = IS_ENABLED(CONFIG_CPU_CP15) ? setup_vbar() : 0;

Yes that certainly is better.

Regards
afzal