提交 40a1db24 编写于 作者: W Will Deacon

arm64: elf: advertise 8.1 atomic instructions as new hwcap

The ARM v8.1 architecture introduces new atomic instructions to the A64
instruction set for things like cmpxchg, so advertise their availability
to userspace using a hwcap.
Reviewed-by: NSteve Capper <steve.capper@arm.com>
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
上级 c275f76b
......@@ -27,5 +27,6 @@
#define HWCAP_SHA1 (1 << 5)
#define HWCAP_SHA2 (1 << 6)
#define HWCAP_CRC32 (1 << 7)
#define HWCAP_ATOMICS (1 << 8)
#endif /* _UAPI__ASM_HWCAP_H */
......@@ -278,6 +278,19 @@ static void __init setup_processor(void)
if (block && !(block & 0x8))
elf_hwcap |= HWCAP_CRC32;
block = (features >> 20) & 0xf;
if (!(block & 0x8)) {
switch (block) {
default:
case 2:
elf_hwcap |= HWCAP_ATOMICS;
case 1:
/* RESERVED */
case 0:
break;
}
}
#ifdef CONFIG_COMPAT
/*
* ID_ISAR5_EL1 carries similar information as above, but pertaining to
......@@ -457,6 +470,7 @@ static const char *hwcap_str[] = {
"sha1",
"sha2",
"crc32",
"atomics",
NULL
};
......
Markdown is supported
0% .
You are about to add 0 people to the discussion. Proceed with caution.
先完成此消息的编辑!
想要评论请 注册