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Date:   Tue, 10 Nov 2020 18:45:53 +1000
From:   Nicholas Piggin <npiggin@gmail.com>
Subject: Re: [PATCH v2 1/3] powerpc/64s: Replace RFI by RFI_TO_KERNEL and
 remove RFI
To:     Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Christophe Leroy <christophe.leroy@csgroup.eu>,
        Michael Ellerman <mpe@ellerman.id.au>,
        Paul Mackerras <paulus@samba.org>
Cc:     linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org
References: <7719261b0a0d2787772339484c33eb809723bca7.1604854583.git.christophe.leroy@csgroup.eu>
In-Reply-To: <7719261b0a0d2787772339484c33eb809723bca7.1604854583.git.christophe.leroy@csgroup.eu>
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Excerpts from Christophe Leroy's message of November 9, 2020 2:57 am:
> In head_64.S, we have two places using RFI to return to
> kernel. Use RFI_TO_KERNEL instead.
>=20
> They are the two only places using RFI on book3s/64, so
> the RFI macro can go away.

Looks good to me.

Acked-by: Nicholas Piggin <npiggin@gmail.com>

>=20
> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
> ---
>  arch/powerpc/include/asm/ppc_asm.h | 1 -
>  arch/powerpc/kernel/head_64.S      | 9 +++++++--
>  2 files changed, 7 insertions(+), 3 deletions(-)
>=20
> diff --git a/arch/powerpc/include/asm/ppc_asm.h b/arch/powerpc/include/as=
m/ppc_asm.h
> index 511786f0e40d..bedf3eb52ebc 100644
> --- a/arch/powerpc/include/asm/ppc_asm.h
> +++ b/arch/powerpc/include/asm/ppc_asm.h
> @@ -495,7 +495,6 @@ END_FTR_SECTION_NESTED(CPU_FTR_CELL_TB_BUG, CPU_FTR_C=
ELL_TB_BUG, 96)
>  #endif
> =20
>  #ifdef CONFIG_PPC_BOOK3S_64
> -#define RFI		rfid
>  #define MTMSRD(r)	mtmsrd	r
>  #define MTMSR_EERI(reg)	mtmsrd	reg,1
>  #else
> diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.=
S
> index 1510b2a56669..ecf9a88988ff 100644
> --- a/arch/powerpc/kernel/head_64.S
> +++ b/arch/powerpc/kernel/head_64.S
> @@ -41,6 +41,11 @@
>  #include <asm/ppc-opcode.h>
>  #include <asm/export.h>
>  #include <asm/feature-fixups.h>
> +#ifdef CONFIG_PPC_BOOK3S
> +#include <asm/exception-64s.h>
> +#else
> +#include <asm/exception-64e.h>
> +#endif
> =20
>  /* The physical memory is laid out such that the secondary processor
>   * spin code sits at 0x0000...0x00ff. On server, the vectors follow
> @@ -829,7 +834,7 @@ __secondary_start:
> =20
>  	mtspr	SPRN_SRR0,r3
>  	mtspr	SPRN_SRR1,r4
> -	RFI
> +	RFI_TO_KERNEL
>  	b	.	/* prevent speculative execution */
> =20
>  /*=20
> @@ -966,7 +971,7 @@ start_here_multiplatform:
>  	ld	r4,PACAKMSR(r13)
>  	mtspr	SPRN_SRR0,r3
>  	mtspr	SPRN_SRR1,r4
> -	RFI
> +	RFI_TO_KERNEL
>  	b	.	/* prevent speculative execution */
> =20
>  	/* This is where all platforms converge execution */
> --=20
> 2.25.0
>=20
>=20