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authorDave Martin <Dave.Martin@arm.com>2019-06-03 16:35:02 +0100
committerWill Deacon <will.deacon@arm.com>2019-06-05 13:05:28 +0100
commit78ed70bf3a923f1965e3c19f544677d418397108 (patch)
treeeea8210beec14f5d0c85f793af4fea631ff4d74d /arch/arm64/kernel/cpufeature.c
parent1e29ab3186e33c77dbb2d7566172a205b59fa390 (diff)
downloadlwn-78ed70bf3a923f1965e3c19f544677d418397108.tar.gz
lwn-78ed70bf3a923f1965e3c19f544677d418397108.zip
arm64: cpufeature: Fix missing ZFR0 in __read_sysreg_by_encoding()
In commit 06a916feca2b ("arm64: Expose SVE2 features for userspace"), new hwcaps are added that are detected via fields in the SVE-specific ID register ID_AA64ZFR0_EL1. In order to check compatibility of secondary cpus with the hwcaps established at boot, the cpufeatures code uses __read_sysreg_by_encoding() to read this ID register based on the sys_reg field of the arm64_elf_hwcaps[] table. This leads to a kernel splat if an hwcap uses an ID register that __read_sysreg_by_encoding() doesn't explicitly handle, as now happens when exercising cpu hotplug on an SVE2-capable platform. So fix it by adding the required case in there. Fixes: 06a916feca2b ("arm64: Expose SVE2 features for userspace") Signed-off-by: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'arch/arm64/kernel/cpufeature.c')
-rw-r--r--arch/arm64/kernel/cpufeature.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index ca27e08e3d8a..80babf451519 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -830,6 +830,7 @@ static u64 __read_sysreg_by_encoding(u32 sys_id)
read_sysreg_case(SYS_ID_AA64PFR0_EL1);
read_sysreg_case(SYS_ID_AA64PFR1_EL1);
+ read_sysreg_case(SYS_ID_AA64ZFR0_EL1);
read_sysreg_case(SYS_ID_AA64DFR0_EL1);
read_sysreg_case(SYS_ID_AA64DFR1_EL1);
read_sysreg_case(SYS_ID_AA64MMFR0_EL1);