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authorMark Rutland <mark.rutland@arm.com>2014-11-25 13:27:41 +0000
committerWill Deacon <will.deacon@arm.com>2014-11-25 15:56:43 +0000
commit9760270c36a4d2ac640ea6294f4f8634a8b27121 (patch)
treebe7e969449fcf8825f5b55ed89ebb8213163a27e
parent1cefdaea613bcd247b2235079fcbb0ca4687542d (diff)
downloadop-kernel-dev-9760270c36a4d2ac640ea6294f4f8634a8b27121.zip
op-kernel-dev-9760270c36a4d2ac640ea6294f4f8634a8b27121.tar.gz
arm64: sanity checks: ignore ID_MMFR0.AuxReg
It seems that Cortex-A53 r0p4 added support for AIFSR and ADFSR, and ID_MMFR0.AuxReg has been updated accordingly to report this fact. As Cortex-A53 could be paired with CPUs which do not implement these registers (e.g. all current revisions of Cortex-A57), this may trigger a sanity check failure at boot. The AuxReg value describes the availability of the ACTLR, AIFSR, and ADFSR registers, which are only of use to 32-bit guest OSs, and have IMPLEMENTATION DEFINED contents. Given the nature of these registers it is likely that KVM will need to trap accesses regardless of whether the CPUs are heterogeneous. This patch masks out the ID_MMFR0.AuxReg value from the sanity checks, preventing spurious warnings at boot time. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reported-by: Andre Przywara <andre.przywara@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
-rw-r--r--arch/arm64/kernel/cpuinfo.c7
1 files changed, 6 insertions, 1 deletions
diff --git a/arch/arm64/kernel/cpuinfo.c b/arch/arm64/kernel/cpuinfo.c
index 16d6d03..01994d4 100644
--- a/arch/arm64/kernel/cpuinfo.c
+++ b/arch/arm64/kernel/cpuinfo.c
@@ -144,7 +144,12 @@ static void cpuinfo_sanity_check(struct cpuinfo_arm64 *cur)
diff |= CHECK(id_isar3, boot, cur, cpu);
diff |= CHECK(id_isar4, boot, cur, cpu);
diff |= CHECK(id_isar5, boot, cur, cpu);
- diff |= CHECK(id_mmfr0, boot, cur, cpu);
+ /*
+ * Regardless of the value of the AuxReg field, the AIFSR, ADFSR, and
+ * ACTLR formats could differ across CPUs and therefore would have to
+ * be trapped for virtualization anyway.
+ */
+ diff |= CHECK_MASK(id_mmfr0, 0xff0fffff, boot, cur, cpu);
diff |= CHECK(id_mmfr1, boot, cur, cpu);
diff |= CHECK(id_mmfr2, boot, cur, cpu);
diff |= CHECK(id_mmfr3, boot, cur, cpu);
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