ARM: 8319/1: advertise availability of v8 Crypto instructions (a092aedb) · Commits · 戴 / test

When running the 32-bit ARM kernel on ARMv8 capable bare metal (e.g., 32-bit Android userland and kernel on a Cortex-A53), or as a KVM guest on a 64-bit host, we should advertise the availability of the Crypto instructions, so that userland libraries such as OpenSSL may use them. (Support for the v8 Crypto instructions in the 32-bit build was added to OpenSSL more than six months ago) This adds the ID feature bit detection, and sets elf_hwcap2 accordingly. Signed-off-by:

Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by:

Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/kernel/setup.c

+22 −0

Original line number	Diff line number	Diff line
		@@ -376,6 +376,7 @@ void __init early_print(const char *str, ...)
		static void __init cpuid_init_hwcaps(void)
		{
		int block;
		u32 isar5;

		if (cpu_architecture() < CPU_ARCH_ARMv7)
		return;
		@@ -390,6 +391,27 @@ static void __init cpuid_init_hwcaps(void)
		block = cpuid_feature_extract(CPUID_EXT_MMFR0, 0);
		if (block >= 5)
		elf_hwcap \|= HWCAP_LPAE;

		/* check for supported v8 Crypto instructions */
		isar5 = read_cpuid_ext(CPUID_EXT_ISAR5);

		block = cpuid_feature_extract_field(isar5, 4);
		if (block >= 2)
		elf_hwcap2 \|= HWCAP2_PMULL;
		if (block >= 1)
		elf_hwcap2 \|= HWCAP2_AES;

		block = cpuid_feature_extract_field(isar5, 8);
		if (block >= 1)
		elf_hwcap2 \|= HWCAP2_SHA1;

		block = cpuid_feature_extract_field(isar5, 12);
		if (block >= 1)
		elf_hwcap2 \|= HWCAP2_SHA2;

		block = cpuid_feature_extract_field(isar5, 16);
		if (block >= 1)
		elf_hwcap2 \|= HWCAP2_CRC32;
		}

		static void __init elf_hwcap_fixup(void)

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