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From: Jingyi Wang <wangjingyi11@huawei.com>
To: <kvm@vger.kernel.org>, <kvmarm@lists.cs.columbia.edu>,
	<linux-arm-kernel@lists.infradead.org>
Cc: catalin.marinas@arm.com, fanhenglong@huawei.com,
	prime.zeng@hisilicon.com, maz@kernel.org, will@kernel.org
Subject: [RFC PATCH 1/4] arm64: cpufeature: TWED support detection
Date: Tue, 29 Sep 2020 17:17:24 +0800	[thread overview]
Message-ID: <20200929091727.8692-2-wangjingyi11@huawei.com> (raw)
In-Reply-To: <20200929091727.8692-1-wangjingyi11@huawei.com>

From: Zengruan Ye <yezengruan@huawei.com>

TWE Delay is an optional feature in ARMv8.6 Extentions. This patch
detect this feature.

Signed-off-by: Zengruan Ye <yezengruan@huawei.com>
Signed-off-by: Jingyi Wang <wangjingyi11@huawei.com>
---
 arch/arm64/Kconfig               | 10 ++++++++++
 arch/arm64/include/asm/cpucaps.h |  3 ++-
 arch/arm64/kernel/cpufeature.c   | 12 ++++++++++++
 3 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 6d232837cbee..fe66f4fc5f49 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -1666,6 +1666,16 @@ config ARCH_RANDOM
 
 endmenu
 
+menu "ARMv8.6 architectural features"
+
+config ARM64_TWED
+	bool "Enable suppot for delayed trapping of WFE"
+	default y
+	help
+	  Delayed Trapping of WFE (part of the ARMv8.6 Extensions)
+
+endmenu
+
 config ARM64_SVE
 	bool "ARM Scalable Vector Extension support"
 	default y
diff --git a/arch/arm64/include/asm/cpucaps.h b/arch/arm64/include/asm/cpucaps.h
index 07b643a70710..7b8f018d142b 100644
--- a/arch/arm64/include/asm/cpucaps.h
+++ b/arch/arm64/include/asm/cpucaps.h
@@ -64,7 +64,8 @@
 #define ARM64_BTI				54
 #define ARM64_HAS_ARMv8_4_TTL			55
 #define ARM64_HAS_TLB_RANGE			56
+#define ARM64_HAS_TWED				57
 
-#define ARM64_NCAPS				57
+#define ARM64_NCAPS				58
 
 #endif /* __ASM_CPUCAPS_H */
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 6424584be01e..d042d32a1144 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -2120,6 +2120,18 @@ static const struct arm64_cpu_capabilities arm64_features[] = {
 		.min_field_value = ID_AA64PFR1_BT_BTI,
 		.sign = FTR_UNSIGNED,
 	},
+#endif
+#ifdef CONFIG_ARM64_TWED
+	{
+		.desc = "Delayed Trapping of WFE",
+		.capability = ARM64_HAS_TWED,
+		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
+		.matches = has_cpuid_feature,
+		.sys_reg = SYS_ID_AA64MMFR1_EL1,
+		.field_pos = ID_AA64MMFR1_TWED_SHIFT,
+		.sign = FTR_UNSIGNED,
+		.min_field_value = 1,
+	},
 #endif
 	{},
 };
-- 
2.19.1

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  reply	other threads:[~2020-09-29  9:18 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-29  9:17 [RFC PATCH 0/4] Add support for ARMv8.6 TWED feature Jingyi Wang
2020-09-29  9:17 ` Jingyi Wang [this message]
2020-09-29  9:17 ` [RFC PATCH 2/4] KVM: arm64: Make use of " Jingyi Wang
2020-09-29  9:17 ` [RFC PATCH 3/4] KVM: arm64: Use dynamic TWE Delay value Jingyi Wang
2020-09-29  9:17 ` [RFC PATCH 4/4] KVM: arm64: Add trace for TWED update Jingyi Wang
2020-09-29 10:50 ` [RFC PATCH 0/4] Add support for ARMv8.6 TWED feature Marc Zyngier
2020-09-30  1:21   ` Jingyi Wang
2020-11-13  7:54 ` Jingyi Wang
2020-11-24  3:19   ` Jingyi Wang
2020-11-24 11:02   ` Marc Zyngier
2020-11-26  2:31     ` Jingyi Wang

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