arm64: advertise ARMv8 extensions to 32-bit compat ELF binaries

[firefly-linux-kernel-4.4.55.git] / arch / arm64 / kernel / setup.c

diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
index 74dde302151cb5dfbc2daae333254e674a755061..570af62efb07807c45e42f3a1f56e32392a63df6 100644 (file)
--- a/arch/arm64/kernel/setup.c
+++ b/arch/arm64/kernel/setup.c
@@ -163,6 +163,38 @@ 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)