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

From: Thiago Jung Bauermann
Date: Thu Jul 27 2017 - 16:41:19 EST



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.

> --- 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.

--
Thiago Jung Bauermann
IBM Linux Technology Center