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authorArd Biesheuvel <ard.biesheuvel@linaro.org>2014-03-03 07:34:46 +0000
committerCatalin Marinas <catalin.marinas@arm.com>2014-03-04 08:06:32 +0000
commit4cf761cdccc3b050f768f25dc36342cdfec4efdd (patch)
treedd57fc3def90b6203be901773bc148850df13c3f
parent28964d32d495a0753986d464c48c8e1ae73699be (diff)
downloadlinux-4cf761cdccc3b050f768f25dc36342cdfec4efdd.tar.gz
arm64: advertise ARMv8 extensions to 32-bit compat ELF binaries
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> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
-rw-r--r--arch/arm64/include/asm/hwcap.h6
-rw-r--r--arch/arm64/kernel/setup.c32
2 files changed, 38 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/hwcap.h b/arch/arm64/include/asm/hwcap.h
index 9a4cbd60c88e..024c46183c3c 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 349c49260f09..67da30741a1b 100644
--- a/arch/arm64/kernel/setup.c
+++ b/arch/arm64/kernel/setup.c
@@ -243,6 +243,38 @@ 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)