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

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Message-Id: <877eyt4nqr.fsf@linux.vnet.ibm.com>
Date:   Thu, 27 Jul 2017 17:40:44 -0300
From:   Thiago Jung Bauermann <bauerman@...ux.vnet.ibm.com>
To:     Ram Pai <linuxram@...ibm.com>
Cc:     linuxppc-dev@...ts.ozlabs.org, linux-kernel@...r.kernel.org,
        linux-arch@...r.kernel.org, linux-mm@...ck.org, x86@...nel.org,
        linux-doc@...r.kernel.org, linux-kselftest@...r.kernel.org,
        arnd@...db.de, corbet@....net, mhocko@...nel.org,
        dave.hansen@...el.com, mingo@...hat.com, paulus@...ba.org,
        aneesh.kumar@...ux.vnet.ibm.com, akpm@...ux-foundation.org,
        khandual@...ux.vnet.ibm.com
Subject: Re: [RFC v6 15/62] powerpc: helper functions to initialize AMR, IAMR and UMOR registers


Ram Pai <linuxram@...ibm.com> 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@...ibm.com>

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