Re: [RFC v6 15/62] powerpc: helper functions to initialize AMR, IAMR and UMOR registers

[Ram Pai]

On Thu, Jul 27, 2017 at 05:40:44PM -0300, Thiago Jung Bauermann wrote:
> 
> Ram Pai <linuxram@xxxxxxxxxx> writes:
> 
> > Introduce helper functions that can initialize the bits in the AMR,
> > IAMR and UMOR register; the bits that correspond to the given pkey.
> >
> > Signed-off-by: Ram Pai <linuxram@xxxxxxxxxx>
> 
> s/UMOR/UAMOR/ here and in the subject as well.

yes. fixed it.

> 
> > --- a/arch/powerpc/mm/pkeys.c
> > +++ b/arch/powerpc/mm/pkeys.c
> > @@ -16,3 +16,47 @@
> >  #include <linux/pkeys.h>                /* PKEY_*                       */
> >
> >  bool pkey_inited;
> > +#define pkeyshift(pkey) ((arch_max_pkey()-pkey-1) * AMR_BITS_PER_PKEY)
> > +
> > +static inline void init_amr(int pkey, u8 init_bits)
> > +{
> > +	u64 new_amr_bits = (((u64)init_bits & 0x3UL) << pkeyshift(pkey));
> > +	u64 old_amr = read_amr() & ~((u64)(0x3ul) << pkeyshift(pkey));
> > +
> > +	write_amr(old_amr | new_amr_bits);
> > +}
> > +
> > +static inline void init_iamr(int pkey, u8 init_bits)
> > +{
> > +	u64 new_iamr_bits = (((u64)init_bits & 0x3UL) << pkeyshift(pkey));
> > +	u64 old_iamr = read_iamr() & ~((u64)(0x3ul) << pkeyshift(pkey));
> > +
> > +	write_amr(old_iamr | new_iamr_bits);
> > +}
> 
> init_iamr should call write_iamr, not write_amr.

excellent catch. thanks.
RP