From: Amit Daniel Kachhap <amit.kachhap@arm.com>
To: Russell King <linux@armlinux.org.uk>
Cc: patches@armlinux.org.uk, linux-arm-kernel@lists.infradead.org,
Amit Daniel Kachhap <amit.kachhap@arm.com>
Subject: [PATCH 4/8] ARM: vfp: Add hwcap for FEAT_FHM
Date: Wed, 26 Oct 2022 11:19:57 +0530 [thread overview]
Message-ID: <20221026055001.12986-5-amit.kachhap@arm.com> (raw)
In-Reply-To: <20221026055001.12986-1-amit.kachhap@arm.com>
Floating-point half-precision multiplication (FHM) is a feature present
in AArch32 state for Armv8 and is represented by ISAR6.FHM identification
register.
This feature denotes the presence of VFMAL and VMFSL instructions and
hence adding a hwcap will enable the userspace to check it before
trying to use those instructions.
Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
---
arch/arm/include/uapi/asm/hwcap.h | 1 +
arch/arm/kernel/setup.c | 1 +
arch/arm/vfp/vfpmodule.c | 6 ++++++
3 files changed, 8 insertions(+)
diff --git a/arch/arm/include/uapi/asm/hwcap.h b/arch/arm/include/uapi/asm/hwcap.h
index 64f3608e6f1b..3d168d4f2a51 100644
--- a/arch/arm/include/uapi/asm/hwcap.h
+++ b/arch/arm/include/uapi/asm/hwcap.h
@@ -31,6 +31,7 @@
#define HWCAP_FPHP (1 << 22)
#define HWCAP_ASIMDHP (1 << 23)
#define HWCAP_ASIMDDP (1 << 24)
+#define HWCAP_ASIMDFHM (1 << 25)
/*
* HWCAP2 flags - for elf_hwcap2 (in kernel) and AT_HWCAP2
diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index c55ff1110152..5e8bf2d5e516 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -1252,6 +1252,7 @@ static const char *hwcap_str[] = {
"fphp",
"asimdhp",
"asimddp",
+ "asimdfhm",
NULL
};
diff --git a/arch/arm/vfp/vfpmodule.c b/arch/arm/vfp/vfpmodule.c
index 70f1e0f4eece..404c4f901132 100644
--- a/arch/arm/vfp/vfpmodule.c
+++ b/arch/arm/vfp/vfpmodule.c
@@ -845,6 +845,12 @@ static int __init vfp_init(void)
isar6 = read_cpuid_ext(CPUID_EXT_ISAR6);
if (cpuid_feature_extract_field(isar6, 4) == 0x1)
elf_hwcap |= HWCAP_ASIMDDP;
+ /*
+ * Check for the presence of Advanced SIMD Floating point
+ * half-precision multiplication instructions.
+ */
+ if (cpuid_feature_extract_field(isar6, 8) == 0x1)
+ elf_hwcap |= HWCAP_ASIMDFHM;
/* Extract the architecture version on pre-cpuid scheme */
} else {
--
2.17.1
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next prev parent reply other threads:[~2022-10-26 5:52 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-26 5:49 [PATCH 0/8] ARM: Expose Armv8 AArch32 features via hwcap Amit Daniel Kachhap
2022-10-26 5:49 ` [PATCH 1/8] ARM: Define Armv8 registers in AArch32 state Amit Daniel Kachhap
2022-10-26 5:49 ` [PATCH 2/8] ARM: vfp: Add hwcap FPHP and ASIMDHP for FEAT_FP16 Amit Daniel Kachhap
2022-10-26 5:49 ` [PATCH 3/8] ARM: vfp: Add hwcap for FEAT_DotProd Amit Daniel Kachhap
2022-10-26 5:49 ` Amit Daniel Kachhap [this message]
2022-10-26 5:49 ` [PATCH 5/8] ARM: vfp: Add hwcap for FEAT_AA32BF16 Amit Daniel Kachhap
2022-10-26 5:49 ` [PATCH 6/8] ARM: vfp: Add hwcap for FEAT_AA32I8MM Amit Daniel Kachhap
2022-10-26 5:50 ` [PATCH 7/8] ARM: Add hwcap for Speculation Barrier(SB) Amit Daniel Kachhap
2022-11-16 14:06 ` Linus Walleij
2022-11-17 10:19 ` Amit Daniel Kachhap
2022-11-17 11:14 ` Robin Murphy
2022-10-26 5:50 ` [PATCH 8/8] ARM: Add hwcap for Speculative Store Bypassing Safe Amit Daniel Kachhap
2022-11-16 13:51 ` [PATCH 0/8] ARM: Expose Armv8 AArch32 features via hwcap Linus Walleij
2022-11-17 6:19 ` Amit Kachhap
2022-11-21 19:04 ` Russell King (Oracle)
2022-11-22 12:24 ` Amit Daniel Kachhap
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