From: Mark Brown <broonie@kernel.org>
To: Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>,
Eric Biederman <ebiederm@xmission.com>,
Kees Cook <keescook@chromium.org>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>,
Szabolcs Nagy <szabolcs.nagy@arm.com>,
linux-arm-kernel@lists.infradead.org,
Mark Brown <broonie@kernel.org>
Subject: [PATCH v2 4/4] arm64/hwcap: Support FEAT_EBF16
Date: Mon, 20 Jun 2022 13:54:51 +0100 [thread overview]
Message-ID: <20220620125451.653507-5-broonie@kernel.org> (raw)
In-Reply-To: <20220620125451.653507-1-broonie@kernel.org>
The v9.2 feature FEAT_EBF16 provides support for an extended BFloat16 mode.
Allow userspace to discover system support for this feature by adding a
hwcap for it.
Signed-off-by: Mark Brown <broonie@kernel.org>
---
Documentation/arm64/elf_hwcaps.rst | 4 ++++
arch/arm64/include/asm/hwcap.h | 1 +
arch/arm64/include/uapi/asm/hwcap.h | 1 +
arch/arm64/kernel/cpufeature.c | 1 +
arch/arm64/kernel/cpuinfo.c | 1 +
5 files changed, 8 insertions(+)
diff --git a/Documentation/arm64/elf_hwcaps.rst b/Documentation/arm64/elf_hwcaps.rst
index 5f4d89c4afe2..4dab74a70cc1 100644
--- a/Documentation/arm64/elf_hwcaps.rst
+++ b/Documentation/arm64/elf_hwcaps.rst
@@ -301,6 +301,10 @@ HWCAP2_WFXT
Functionality implied by ID_AA64ISAR2_EL1.WFXT == 0b0010.
+HWCAP3_EBF16
+
+ Functionality implied by ID_AA64ISAR1_EL1.BF16 == 0b0010.
+
4. Unused AT_HWCAP bits
-----------------------
diff --git a/arch/arm64/include/asm/hwcap.h b/arch/arm64/include/asm/hwcap.h
index 1ef208ab6895..cf670e4afc16 100644
--- a/arch/arm64/include/asm/hwcap.h
+++ b/arch/arm64/include/asm/hwcap.h
@@ -123,6 +123,7 @@
#define KERNEL_HWCAP_WFXT __khwcap2_feature(WFXT)
#define __khwcap3_feature(x) (const_ilog2(HWCAP3_ ## x) + KHWCAP_OFFSET(3))
+#define KERNEL_HWCAP_EBF16 __khwcap3_feature(EBF16)
/*
* This yields a mask that user programs can use to figure out what
diff --git a/arch/arm64/include/uapi/asm/hwcap.h b/arch/arm64/include/uapi/asm/hwcap.h
index 7b818f8fc01b..3b6644f0c07f 100644
--- a/arch/arm64/include/uapi/asm/hwcap.h
+++ b/arch/arm64/include/uapi/asm/hwcap.h
@@ -92,5 +92,6 @@
/*
* HWCAP3 flags - for AT_HWCAP3
*/
+#define HWCAP3_EBF16 (1 << 0)
#endif /* _UAPI__ASM_HWCAP_H */
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 7605b213d9db..79850a0cd563 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -2623,6 +2623,7 @@ static const struct arm64_cpu_capabilities arm64_elf_hwcaps[] = {
HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_FRINTTS_SHIFT, 4, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_FRINT),
HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_SB_SHIFT, 4, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SB),
HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_BF16_SHIFT, 4, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_BF16),
+ HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_BF16_SHIFT, 4, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_EBF16),
HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_DGH_SHIFT, 4, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_DGH),
HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_I8MM_SHIFT, 4, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_I8MM),
HWCAP_CAP(SYS_ID_AA64MMFR2_EL1, ID_AA64MMFR2_AT_SHIFT, 4, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_USCAT),
diff --git a/arch/arm64/kernel/cpuinfo.c b/arch/arm64/kernel/cpuinfo.c
index 8eff0a34ffd4..2ca131243c30 100644
--- a/arch/arm64/kernel/cpuinfo.c
+++ b/arch/arm64/kernel/cpuinfo.c
@@ -107,6 +107,7 @@ static const char *const hwcap_str[] = {
[KERNEL_HWCAP_SME_F32F32] = "smef32f32",
[KERNEL_HWCAP_SME_FA64] = "smefa64",
[KERNEL_HWCAP_WFXT] = "wfxt",
+ [KERNEL_HWCAP_EBF16] = "ebf16",
};
#ifdef CONFIG_COMPAT
--
2.30.2
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next prev parent reply other threads:[~2022-06-20 13:23 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-20 12:54 [PATCH v2 0/4] arm64: Add AT_HWCAP3 Mark Brown
2022-06-20 12:54 ` [PATCH v2 1/4] arm64/cpufeature: Store elf_hwcaps as an array rather than unsigned long Mark Brown
2022-06-28 14:21 ` Will Deacon
2022-06-28 15:06 ` Mark Brown
2022-06-29 10:01 ` Szabolcs Nagy
2022-06-29 11:44 ` Mark Brown
2022-06-29 12:06 ` Szabolcs Nagy
2022-06-29 13:55 ` Catalin Marinas
2022-06-29 15:07 ` Mark Brown
2022-06-20 12:54 ` [PATCH v2 2/4] elf: Allow architectures to provide AT_HWCAP3 Mark Brown
2022-06-20 12:54 ` [PATCH v2 3/4] arm64/cpufeature: Support AT_HWCAP3 Mark Brown
2022-06-20 12:54 ` Mark Brown [this message]
2022-07-05 17:53 ` [PATCH v2 0/4] arm64: Add AT_HWCAP3 Mark Brown
2022-07-06 9:02 ` Szabolcs Nagy
2022-07-06 10:08 ` Marc Zyngier
2022-07-06 13:48 ` Mark Brown
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