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From: Ard Biesheuvel <ard.biesheuvel@linaro.org>
To: linux@arm.linux.org.uk, catalin.marinas@arm.com,
	viro@zeniv.linux.org.uk, nico@linaro.org,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Subject: [PATCH v2 5/5] arm64: advertise ARMv8 extensions to 32-bit compat ELF binaries
Date: Mon, 23 Dec 2013 15:06:32 +0100	[thread overview]
Message-ID: <1387807592-26375-6-git-send-email-ard.biesheuvel@linaro.org> (raw)
In-Reply-To: <1387807592-26375-1-git-send-email-ard.biesheuvel@linaro.org>

This adds support for advertising the presence of ARMv8 Crypto
Extensions in the Aarch32 execution state to 32-bit ELF binaries
running in 32-bit compat mode under the arm64 kernel.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
 arch/arm64/include/asm/hwcap.h |  6 ++++++
 arch/arm64/kernel/setup.c      | 32 ++++++++++++++++++++++++++++++++
 2 files changed, 38 insertions(+)

diff --git a/arch/arm64/include/asm/hwcap.h b/arch/arm64/include/asm/hwcap.h
index 9a4cbd6..024c461 100644
--- a/arch/arm64/include/asm/hwcap.h
+++ b/arch/arm64/include/asm/hwcap.h
@@ -32,6 +32,12 @@
 #define COMPAT_HWCAP_IDIV	(COMPAT_HWCAP_IDIVA|COMPAT_HWCAP_IDIVT)
 #define COMPAT_HWCAP_EVTSTRM	(1 << 21)
 
+#define COMPAT_HWCAP2_AES	(1 << 0)
+#define COMPAT_HWCAP2_PMULL	(1 << 1)
+#define COMPAT_HWCAP2_SHA1	(1 << 2)
+#define COMPAT_HWCAP2_SHA2	(1 << 3)
+#define COMPAT_HWCAP2_CRC32	(1 << 4)
+
 #ifndef __ASSEMBLY__
 /*
  * This yields a mask that user programs can use to figure out what
diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
index 15f3bd2..c36cab8 100644
--- a/arch/arm64/kernel/setup.c
+++ b/arch/arm64/kernel/setup.c
@@ -174,6 +174,38 @@ static void __init setup_processor(void)
 	block = (features >> 16) & 0xf;
 	if (block && !(block & 0x8))
 		elf_hwcap |= HWCAP_CRC32;
+
+#ifdef CONFIG_COMPAT
+	/*
+	 * ID_ISAR5_EL1 carries similar information as above, but pertaining to
+	 * the Aarch32 32-bit execution state.
+	 */
+	features = read_cpuid(ID_ISAR5_EL1);
+	block = (features >> 4) & 0xf;
+	if (!(block & 0x8)) {
+		switch (block) {
+		default:
+		case 2:
+			compat_elf_hwcap2 |= COMPAT_HWCAP2_PMULL;
+		case 1:
+			compat_elf_hwcap2 |= COMPAT_HWCAP2_AES;
+		case 0:
+			break;
+		}
+	}
+
+	block = (features >> 8) & 0xf;
+	if (block && !(block & 0x8))
+		compat_elf_hwcap2 |= COMPAT_HWCAP2_SHA1;
+
+	block = (features >> 12) & 0xf;
+	if (block && !(block & 0x8))
+		compat_elf_hwcap2 |= COMPAT_HWCAP2_SHA2;
+
+	block = (features >> 16) & 0xf;
+	if (block && !(block & 0x8))
+		compat_elf_hwcap2 |= COMPAT_HWCAP2_CRC32;
+#endif
 }
 
 static void __init setup_machine_fdt(phys_addr_t dt_phys)
-- 
1.8.3.2


  parent reply	other threads:[~2013-12-23 14:06 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-12-23 14:06 [PATCH v2 0/5] arm64: advertise availability of CRC and crypto instructions Ard Biesheuvel
2013-12-23 14:06 ` [PATCH v2 1/5] ARM: add support for AT_HWCAP2 ELF auxv entry Ard Biesheuvel
2014-01-20 17:39   ` Catalin Marinas
2013-12-23 14:06 ` [PATCH v2 2/5] binfmt_elf: add ELF_HWCAP2 to compat auxv entries Ard Biesheuvel
2014-01-20 17:40   ` Catalin Marinas
2013-12-23 14:06 ` [PATCH v2 3/5] arm64: add AT_HWCAP2 support for 32-bit compat Ard Biesheuvel
2013-12-23 14:06 ` [PATCH v2 4/5] ARM: introduce HWCAP2 feature bits for ARMv8 Crypto Extensions Ard Biesheuvel
2014-01-20 17:41   ` Catalin Marinas
2013-12-23 14:06 ` Ard Biesheuvel [this message]
2014-01-20 17:43   ` [PATCH v2 5/5] arm64: advertise ARMv8 extensions to 32-bit compat ELF binaries Catalin Marinas
2014-01-07  9:22 ` [PATCH v2 0/5] arm64: advertise availability of CRC and crypto instructions Ard Biesheuvel
2014-01-20 17:38 ` Catalin Marinas
2014-01-20 17:44   ` Nicolas Pitre
2014-01-20 18:03     ` Ard Biesheuvel
2014-01-20 18:17       ` Nicolas Pitre
2014-01-20 18:32         ` Ard Biesheuvel
2014-01-20 18:55           ` Nicolas Pitre
2014-01-20 19:01             ` Ard Biesheuvel
2014-01-20 19:42               ` Nicolas Pitre
2014-01-21 15:12                 ` Catalin Marinas

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