From: Michael Ellerman <patch-notifications@ellerman.id.au>
To: Michael Ellerman <mpe@ellerman.id.au>, linuxppc-dev@ozlabs.org
Cc: msuchanek@suse.de, linux-kernel@vger.kernel.org, npiggin@gmail.com
Subject: Re: [1/6] powerpc/64s: Add barrier_nospec
Date: Tue, 5 Jun 2018 00:10:39 +1000 (AEST) [thread overview]
Message-ID: <40zxfm40PKz9s0w@ozlabs.org> (raw)
In-Reply-To: <20180424041559.32410-1-mpe@ellerman.id.au>
On Tue, 2018-04-24 at 04:15:54 UTC, Michael Ellerman wrote:
> From: Michal Suchanek <msuchanek@suse.de>
>
> A no-op form of ori (or immediate of 0 into r31 and the result stored
> in r31) has been re-tasked as a speculation barrier. The instruction
> only acts as a barrier on newer machines with appropriate firmware
> support. On older CPUs it remains a harmless no-op.
>
> Implement barrier_nospec using this instruction.
>
> mpe: The semantics of the instruction are believed to be that it
> prevents execution of subsequent instructions until preceding branches
> have been fully resolved and are no longer executing speculatively.
> There is no further documentation available at this time.
>
> Signed-off-by: Michal Suchanek <msuchanek@suse.de>
> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Series applied to powerpc next.
https://git.kernel.org/powerpc/c/a6b3964ad71a61bb7c61d80a60bea7
cheers
prev parent reply other threads:[~2018-06-04 14:10 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-04-24 4:15 [PATCH 1/6] powerpc/64s: Add barrier_nospec Michael Ellerman
2018-04-24 4:15 ` [PATCH 2/6] powerpc/64s: Add support for ori barrier_nospec patching Michael Ellerman
2018-04-26 16:10 ` Michal Suchánek
2018-05-01 12:25 ` Michael Ellerman
2018-04-24 4:15 ` [PATCH 3/6] powerpc/64s: Patch barrier_nospec in modules Michael Ellerman
2018-05-03 13:15 ` Michal Suchánek
2018-04-24 4:15 ` [PATCH 4/6] powerpc/64s: Enable barrier_nospec based on firmware settings Michael Ellerman
2018-04-26 16:02 ` Michal Suchánek
2018-05-01 11:11 ` Michael Ellerman
2018-05-02 11:41 ` Michal Suchánek
2018-05-04 0:58 ` Michael Ellerman
2018-04-24 4:15 ` [PATCH 5/6] powerpc: Use barrier_nospec in copy_from_user() Michael Ellerman
2018-04-24 4:15 ` [PATCH 6/6] powerpc/64: Use barrier_nospec in syscall entry Michael Ellerman
2018-04-24 5:44 ` [PATCH 1/6] powerpc/64s: Add barrier_nospec Nicholas Piggin
2018-05-28 13:19 ` [PATCH] powerpc/64s: Enhance the information in cpu_show_spectre_v1() Michal Suchanek
2018-05-29 14:03 ` kbuild test robot
2018-05-29 14:13 ` Christophe LEROY
2018-05-29 14:46 ` Michal Suchánek
2018-05-29 15:24 ` Christophe Leroy
2018-05-29 16:15 ` Joe Perches
2018-06-04 14:11 ` Michael Ellerman
2018-06-04 14:10 ` Michael Ellerman [this message]
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