Commit ce483549 authored by Amit Daniel Kachhap's avatar Amit Daniel Kachhap Committed by Russell King (Oracle)
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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: default avatarLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: default avatarAmit Daniel Kachhap <amit.kachhap@arm.com>
Signed-off-by: default avatarRussell King (Oracle) <rmk+kernel@armlinux.org.uk>
parent 62ea0d87

arch/arm/include/uapi/asm/hwcap.h

+1 −0
Original line number Diff line number Diff line
@@ -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

arch/arm/kernel/setup.c

+1 −0
Original line number Diff line number Diff line
@@ -1252,6 +1252,7 @@ static const char *hwcap_str[] = { 
	"fphp",

	"asimdhp",

	"asimddp",

	"asimdfhm",

	NULL

};

arch/arm/vfp/vfpmodule.c

+6 −0
Original line number Diff line number Diff line
@@ -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 {