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From: Amit Daniel Kachhap <amit.kachhap@arm.com>
To: linux-arm-kernel@lists.infradead.org
Cc: Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>,
	Amit Daniel Kachhap <amit.kachhap@arm.com>
Subject: [PATCH 8/8] arm64: Add compat hwcap SSBS
Date: Wed, 26 Oct 2022 11:28:13 +0530	[thread overview]
Message-ID: <20221026055813.13484-9-amit.kachhap@arm.com> (raw)
In-Reply-To: <20221026055813.13484-1-amit.kachhap@arm.com>

This hwcap is added earlier for 32-bit native arm kernel and hence the
corresponding changes added in 32-bit compat arm64 for similar user
interface. Speculative Store Bypass Safe is a feature(FEAT_SSBS) present in
AArch32/AArch64 state for Armv8 and can be identified by PFR2.SSBS
identification register. This hwcap is already advertised in arm64 kernel.

Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
---
 arch/arm64/include/asm/hwcap.h | 1 +
 arch/arm64/kernel/cpufeature.c | 3 ++-
 arch/arm64/kernel/cpuinfo.c    | 1 +
 3 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/include/asm/hwcap.h b/arch/arm64/include/asm/hwcap.h
index adfc6be14c53..e7c3dd8f71e0 100644
--- a/arch/arm64/include/asm/hwcap.h
+++ b/arch/arm64/include/asm/hwcap.h
@@ -44,6 +44,7 @@
 #define COMPAT_HWCAP2_SHA2	(1 << 3)
 #define COMPAT_HWCAP2_CRC32	(1 << 4)
 #define COMPAT_HWCAP2_SB	(1 << 5)
+#define COMPAT_HWCAP2_SSBS	(1 << 6)
 
 #ifndef __ASSEMBLY__
 #include <linux/log2.h>
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 9bc58c3661f4..56e5ab35e942 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -560,7 +560,7 @@ static const struct arm64_ftr_bits ftr_id_pfr1[] = {
 };
 
 static const struct arm64_ftr_bits ftr_id_pfr2[] = {
-	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_PFR2_SSBS_SHIFT, 4, 0),
+	ARM64_FTR_BITS(FTR_VISIBLE, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_PFR2_SSBS_SHIFT, 4, 0),
 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_PFR2_CSV3_SHIFT, 4, 0),
 	ARM64_FTR_END,
 };
@@ -2854,6 +2854,7 @@ static const struct arm64_cpu_capabilities compat_elf_hwcaps[] = {
 	HWCAP_CAP(SYS_ID_ISAR6_EL1, ID_ISAR6_SB_SHIFT, 4, FTR_UNSIGNED, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_SB),
 	HWCAP_CAP(SYS_ID_ISAR6_EL1, ID_ISAR6_BF16_SHIFT, 4, FTR_UNSIGNED, 1, CAP_COMPAT_HWCAP, COMPAT_HWCAP_ASIMDBF16),
 	HWCAP_CAP(SYS_ID_ISAR6_EL1, ID_ISAR6_I8MM_SHIFT, 4, FTR_UNSIGNED, 1, CAP_COMPAT_HWCAP, COMPAT_HWCAP_I8MM),
+	HWCAP_CAP(SYS_ID_PFR2_EL1, ID_PFR2_SSBS_SHIFT, 4, FTR_UNSIGNED, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_SSBS),
 #endif
 	{},
 };
diff --git a/arch/arm64/kernel/cpuinfo.c b/arch/arm64/kernel/cpuinfo.c
index afbceb5b2bab..c49582d1372f 100644
--- a/arch/arm64/kernel/cpuinfo.c
+++ b/arch/arm64/kernel/cpuinfo.c
@@ -159,6 +159,7 @@ static const char *const compat_hwcap2_str[] = {
 	[COMPAT_KERNEL_HWCAP2(SHA2)]	= "sha2",
 	[COMPAT_KERNEL_HWCAP2(CRC32)]	= "crc32",
 	[COMPAT_KERNEL_HWCAP2(SB)]	= "sb",
+	[COMPAT_KERNEL_HWCAP2(SSBS)]	= "ssbs",
 };
 #endif /* CONFIG_COMPAT */
 
-- 
2.17.1


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      parent reply	other threads:[~2022-10-26  6:01 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-10-26  5:58 [PATCH 0/8] arm64: Expose compat Armv8 AArch32 features Amit Daniel Kachhap
2022-10-26  5:58 ` [PATCH 1/8] arm64: cpufeature: Fix the visibility of compat hwcaps Amit Daniel Kachhap
2022-10-26 15:15   ` James Morse
2022-11-02 10:47     ` Amit Kachhap
2022-11-01 19:07   ` Catalin Marinas
2022-10-26  5:58 ` [PATCH 2/8] arm64: Add compat hwcap FPHP and ASIMDHP Amit Daniel Kachhap
2022-11-09 18:00   ` Will Deacon
2022-11-10  4:18     ` Amit Kachhap
2022-11-15 15:32       ` Catalin Marinas
2022-10-26  5:58 ` [PATCH 3/8] arm64: Add compat hwcap ASIMDDP Amit Daniel Kachhap
2022-10-26  5:58 ` [PATCH 4/8] arm64: Add compat hwcap ASIMDFHM Amit Daniel Kachhap
2022-10-26  5:58 ` [PATCH 5/8] arm64: Add compat hwcap ASIMDBF16 Amit Daniel Kachhap
2022-10-26  5:58 ` [PATCH 6/8] arm64: Add compat hwcap I8MM Amit Daniel Kachhap
2022-10-26  5:58 ` [PATCH 7/8] arm64: Add compat hwcap SB Amit Daniel Kachhap
2022-10-26  5:58 ` Amit Daniel Kachhap [this message]

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