summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorAmit Daniel Kachhap <amit.kachhap@arm.com>2022-11-17 08:37:21 +0300
committerRussell King (Oracle) <rmk+kernel@armlinux.org.uk>2022-11-28 14:57:33 +0300
commitce4835497c20991574fde492ab37ec666563d3e4 (patch)
treefc5b68f7321f1e1b76bcf147275fe343ea2318e2
parent62ea0d873af3ef0a7e8387b67241ad43e3d377e1 (diff)
downloadlinux-ce4835497c20991574fde492ab37ec666563d3e4.tar.xz
ARM: 9270/1: vfp: Add hwcap for FEAT_FHM
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. 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>
-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 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 9841b897d476..d88c1326f529 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 {