From: james.morse@arm.com (James Morse)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v3 1/6] arm64: kernel: Add cpuid_feature_extract_field() for 4bit sign extension
Date: Tue, 21 Jul 2015 13:23:26 +0100 [thread overview]
Message-ID: <1437481411-1595-2-git-send-email-james.morse@arm.com> (raw)
In-Reply-To: <1437481411-1595-1-git-send-email-james.morse@arm.com>
Based on arch/arm/include/asm/cputype.h, this function does the
shifting and sign extension necessary when accessing cpu feature fields.
Signed-off-by: James Morse <james.morse@arm.com>
Suggested-by: Russell King <linux@arm.linux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
---
arch/arm64/include/asm/cpufeature.h | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h
index c1044218a63a..9fafa7537997 100644
--- a/arch/arm64/include/asm/cpufeature.h
+++ b/arch/arm64/include/asm/cpufeature.h
@@ -70,6 +70,13 @@ static inline void cpus_set_cap(unsigned int num)
__set_bit(num, cpu_hwcaps);
}
+static inline int __attribute_const__ cpuid_feature_extract_field(u64 features,
+ int field)
+{
+ return (s64)(features << (64 - 4 - field)) >> (64 - 4);
+}
+
+
void check_cpu_capabilities(const struct arm64_cpu_capabilities *caps,
const char *info);
void check_local_cpu_errata(void);
--
2.1.4
next prev parent reply other threads:[~2015-07-21 12:23 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-07-21 12:23 [PATCH v3 0/6] arm64: kernel: Add support for Privileged Access Never James Morse
2015-07-21 12:23 ` James Morse [this message]
2015-07-21 12:32 ` [PATCH v3 1/6] arm64: kernel: Add cpuid_feature_extract_field() for 4bit sign extension Catalin Marinas
2015-07-21 12:23 ` [PATCH v3 2/6] arm64: kernel: preparatory: Move config_sctlr_el1 James Morse
2015-07-21 12:23 ` [PATCH v3 3/6] arm64: kernel: Add cpufeature 'enable' callback James Morse
2015-07-21 12:23 ` [PATCH v3 4/6] arm64: kernel: Add min_field_value and use '>=' for feature detection James Morse
2015-07-21 12:33 ` Catalin Marinas
2015-07-21 12:23 ` [PATCH v3 5/6] arm64: kernel: Add optional CONFIG_ parameter to ALTERNATIVE() James Morse
2015-07-21 12:23 ` [PATCH v3 6/6] arm64: kernel: Add support for Privileged Access Never James Morse
2015-07-21 12:38 ` Catalin Marinas
2015-07-22 17:01 ` Will Deacon
2015-07-22 18:04 ` James Morse
2015-07-22 18:14 ` Will Deacon
2015-07-23 7:58 ` James Morse
2015-07-22 18:05 ` [PATCH v4] " James Morse
2015-07-23 13:07 ` Will Deacon
2015-07-24 15:14 ` James Morse
2015-07-24 16:56 ` Will Deacon
2015-07-23 12:00 ` [PATCH v3 6/6] " Will Deacon
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