From: Will Deacon <will@kernel.org>
To: broonie@kernel.org
Cc: kernel-team@android.com,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Marc Zyngier <maz@kernel.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>,
linux-arm-kernel@lists.infradead.org
Subject: [PATCH 2/2] arm64: Use register field helper in kaslr_requires_kpti()
Date: Wed, 15 Jan 2020 14:29:00 +0000 [thread overview]
Message-ID: <20200115142900.28976-3-will@kernel.org> (raw)
In-Reply-To: <20200115142900.28976-1-will@kernel.org>
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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next prev parent reply other threads:[~2020-01-15 14:29 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-15 14:28 [PATCH 0/2] A couple of cleanups on top of for-next/e0pd Will Deacon
2020-01-15 14:28 ` [PATCH 1/2] arm64: Simplify early check for broken TX1 when KASLR is enabled Will Deacon
2020-01-15 14:29 ` Will Deacon [this message]
2020-01-15 17:06 ` [PATCH 2/2] arm64: Use register field helper in kaslr_requires_kpti() Mark Brown
2020-01-15 15:11 ` [PATCH 0/2] A couple of cleanups on top of for-next/e0pd Catalin Marinas
2020-01-15 16:47 ` Suzuki Kuruppassery Poulose
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