Messages in this thread | | | Date | Thu, 18 Jan 2018 10:52:23 +0100 | From | Cornelia Huck <> | Subject | Re: [PATCH 3/6] s390: add options to change branch prediction behaviour for the kernel |
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On Wed, 17 Jan 2018 10:48:36 +0100 Martin Schwidefsky <schwidefsky@de.ibm.com> wrote:
> Add the PPA instruction to the system entry and exit path to switch > the kernel to a different branch prediction behaviour. The instructions > are added via CPU alternatives and can be disabled with the "nospec" > or the "nobp=0" kernel parameter. If the default behaviour selected > with CONFIG_KERNEL_NOBP is set to "n" then the "nobp=1" parameter can be > used to enable the changed kernel branch prediction. > > Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> > Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> > --- > arch/s390/Kconfig | 17 +++++++++++++ > arch/s390/include/asm/processor.h | 1 + > arch/s390/kernel/alternative.c | 23 ++++++++++++++++++ > arch/s390/kernel/early.c | 2 ++ > arch/s390/kernel/entry.S | 50 ++++++++++++++++++++++++++++++++++++++- > arch/s390/kernel/ipl.c | 1 + > arch/s390/kernel/smp.c | 2 ++ > 7 files changed, 95 insertions(+), 1 deletion(-)
Acked-by: Cornelia Huck <cohuck@redhat.com>
[This looks sane; but as I don't have insight into the details of the new instructions, I don't feel confident enough to give a R-b]
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