[tip: x86/cleanups] x86/idle: Use MONITORX and MWAITX mnemonics in <asm/mwait.h>

From: tip-bot2 for Uros Bizjak
Date: Fri Aug 22 2025 - 08:08:26 EST


The following commit has been merged into the x86/cleanups branch of tip:

Commit-ID: d20a5d96eddb95b4faa33247ec653a580c48fdfa
Gitweb: https://git.kernel.org/tip/d20a5d96eddb95b4faa33247ec653a580c48fdfa
Author: Uros Bizjak <ubizjak@xxxxxxxxx>
AuthorDate: Mon, 16 Jun 2025 10:30:41 +02:00
Committer: Borislav Petkov (AMD) <bp@xxxxxxxxx>
CommitterDate: Fri, 22 Aug 2025 13:52:21 +02:00

x86/idle: Use MONITORX and MWAITX mnemonics in <asm/mwait.h>

Current minimum required version of binutils is 2.30, which supports MONITORX
and MWAITX instruction mnemonics.

Replace the byte-wise specification of MONITORX and MWAITX with these proper
mnemonics.

No functional change intended.

Signed-off-by: Uros Bizjak <ubizjak@xxxxxxxxx>
Signed-off-by: Borislav Petkov (AMD) <bp@xxxxxxxxx>
Link: https://lore.kernel.org/20250616083056.157460-1-ubizjak@xxxxxxxxx
---
arch/x86/include/asm/mwait.h | 8 ++------
1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/arch/x86/include/asm/mwait.h b/arch/x86/include/asm/mwait.h
index 6ca6516..e4815e1 100644
--- a/arch/x86/include/asm/mwait.h
+++ b/arch/x86/include/asm/mwait.h
@@ -36,9 +36,7 @@ static __always_inline void __monitor(const void *eax, u32 ecx, u32 edx)

static __always_inline void __monitorx(const void *eax, u32 ecx, u32 edx)
{
- /* "monitorx %eax, %ecx, %edx" */
- asm volatile(".byte 0x0f, 0x01, 0xfa"
- :: "a" (eax), "c" (ecx), "d"(edx));
+ asm volatile("monitorx" :: "a" (eax), "c" (ecx), "d"(edx));
}

static __always_inline void __mwait(u32 eax, u32 ecx)
@@ -80,9 +78,7 @@ static __always_inline void __mwaitx(u32 eax, u32 ebx, u32 ecx)
{
/* No need for TSA buffer clearing on AMD */

- /* "mwaitx %eax, %ebx, %ecx" */
- asm volatile(".byte 0x0f, 0x01, 0xfb"
- :: "a" (eax), "b" (ebx), "c" (ecx));
+ asm volatile("mwaitx" :: "a" (eax), "b" (ebx), "c" (ecx));
}

/*