[PATCH 2/2] arm64: Use register field helper in kaslr_requires_kpti()
From: Will Deacon <will@kernel.org>
Date: 2020-01-15 14:29:46
Subsystem:
arm64 port (aarch64 architecture), the rest · Maintainers:
Catalin Marinas, Will Deacon, Linus Torvalds
Rather than open-code the extraction of the E0PD field from the MMFR2 register, we can use the cpuid_feature_extract_unsigned_field() helper instead. Signed-off-by: Will Deacon <will@kernel.org> --- arch/arm64/kernel/cpufeature.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index d5242b44dc5a..1ebeb5bc17d2 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c@@ -980,7 +980,6 @@ has_useable_cnp(const struct arm64_cpu_capabilities *entry, int scope) */ bool kaslr_requires_kpti(void) { - u64 ftr; if (!IS_ENABLED(CONFIG_RANDOMIZE_BASE)) return false;
@@ -989,8 +988,9 @@ bool kaslr_requires_kpti(void) * where available. */ if (IS_ENABLED(CONFIG_ARM64_E0PD)) { - ftr = read_sysreg_s(SYS_ID_AA64MMFR2_EL1); - if ((ftr >> ID_AA64MMFR2_E0PD_SHIFT) & 0xf) + u64 mmfr2 = read_sysreg_s(SYS_ID_AA64MMFR2_EL1); + if (cpuid_feature_extract_unsigned_field(mmfr2, + ID_AA64MMFR2_E0PD_SHIFT)) return false; }
--
2.25.0.rc1.283.g88dfdc4193-goog
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