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authorAmit Daniel Kachhap <amit.kachhap@arm.com>2022-11-17 06:42:07 +0100
committerRussell King (Oracle) <rmk+kernel@armlinux.org.uk>2022-11-28 11:57:33 +0000
commit23b6d4ad6e7a3028dd88aff7e2b0e5a81da8565e (patch)
treecf85dff234f31626a5d44cd4220e3fc5c2b4f35e /arch/arm
parentce4835497c20991574fde492ab37ec666563d3e4 (diff)
ARM: 9271/1: vfp: Add hwcap for FEAT_AA32BF16
Advanced SIMD BFloat16 (FEAT_AA32BF16) is a feature present in AArch32 state for Armv8 and is represented by ISAR6.BF16 identification register. This feature denotes the presence of VCVT, VCVTB, VCVTT, VDOT, VFMAB, VFMAT and VMMLA instructions and hence adding a hwcap will enable the userspace to check it before trying to use those instructions. Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Diffstat (limited to 'arch/arm')
-rw-r--r--arch/arm/include/uapi/asm/hwcap.h1
-rw-r--r--arch/arm/kernel/setup.c1
-rw-r--r--arch/arm/vfp/vfpmodule.c6
3 files changed, 8 insertions, 0 deletions
diff --git a/arch/arm/include/uapi/asm/hwcap.h b/arch/arm/include/uapi/asm/hwcap.h
index 3d168d4f2a51..14e260e2d6d0 100644
--- a/arch/arm/include/uapi/asm/hwcap.h
+++ b/arch/arm/include/uapi/asm/hwcap.h
@@ -32,6 +32,7 @@
#define HWCAP_ASIMDHP (1 << 23)
#define HWCAP_ASIMDDP (1 << 24)
#define HWCAP_ASIMDFHM (1 << 25)
+#define HWCAP_ASIMDBF16 (1 << 26)
/*
* 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 d88c1326f529..070067cb6c77 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -1253,6 +1253,7 @@ static const char *hwcap_str[] = {
"asimdhp",
"asimddp",
"asimdfhm",
+ "asimdbf16",
NULL
};
diff --git a/arch/arm/vfp/vfpmodule.c b/arch/arm/vfp/vfpmodule.c
index 404c4f901132..ff574cb8a0b9 100644
--- a/arch/arm/vfp/vfpmodule.c
+++ b/arch/arm/vfp/vfpmodule.c
@@ -851,6 +851,12 @@ static int __init vfp_init(void)
*/
if (cpuid_feature_extract_field(isar6, 8) == 0x1)
elf_hwcap |= HWCAP_ASIMDFHM;
+ /*
+ * Check for the presence of Advanced SIMD Bfloat16
+ * floating point instructions.
+ */
+ if (cpuid_feature_extract_field(isar6, 20) == 0x1)
+ elf_hwcap |= HWCAP_ASIMDBF16;
/* Extract the architecture version on pre-cpuid scheme */
} else {