From mboxrd@z Thu Jan 1 00:00:00 1970 From: will.deacon@arm.com (Will Deacon) Date: Tue, 12 Dec 2017 18:11:56 +0000 Subject: [PATCH v2] arm64: cpu_errata: Add Kryo to Falkor 1003 errata In-Reply-To: <20171129230353.11809-1-sboyd@codeaurora.org> References: <20171129230353.11809-1-sboyd@codeaurora.org> Message-ID: <20171212181156.GA25244@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Stephen, On Wed, Nov 29, 2017 at 03:03:53PM -0800, Stephen Boyd wrote: > The Kryo CPUs are also affected by the Falkor 1003 errata, so > we need to do the same workaround on Kryo CPUs. The MIDR is > slightly more complicated here, where the PART number is not > always the same when looking at all the bits from 15 to 4. Drop > the lower 8 bits and just look at the top 4 to see if it's '2' > and then consider those as Kryo CPUs. This covers all the > combinations without having to list them all out. > > Introduce a new hardware cap bit for the combination of hardware > PAN support and this errata so that we can disable support for > software PAN at runtime if this errata is present and the CPU > doesn't support HW PAN. This happens on some Kryo CPUs where the > HW PAN feature isn't supported but we can't prevent software PAN > from being selected in the configuration. Previously, Falkor CPUs > were all known to have HW PAN support, so we didn't need to worry > about this case. > > Fixes: 38fd94b0275c ("arm64: Work around Falkor erratum 1003") > Signed-off-by: Stephen Boyd > --- Can you respin this on top of for-next/core please? The PAN bits should be much simpler with the KPTI code. Will