diff options
| author | Uros Bizjak <ubizjak@gmail.com> | 2025-04-18 10:07:44 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2025-04-18 10:19:25 +0200 |
| commit | d109ff4f0bc32de354247a6e8ede3ffc8ef14cd0 (patch) | |
| tree | 98c9ddd330bc71e5952b694f10318e1aaaf6b970 | |
| parent | 42c782fae38f0559e6355707ee0afde9ac16dcc3 (diff) | |
x86/asm: Replace "REP; NOP" with PAUSE mnemonic
Current minimum required version of binutils is 2.25,
which supports PAUSE instruction mnemonic.
Replace "REP; NOP" with this proper mnemonic.
No functional change intended.
Reviewed-by: Nikolay Borisov <nik.borisov@suse.com>
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Link: https://lore.kernel.org/r/20250418080805.83679-2-ubizjak@gmail.com
| -rw-r--r-- | arch/x86/boot/boot.h | 2 | ||||
| -rw-r--r-- | arch/x86/include/asm/vdso/processor.h | 4 | ||||
| -rw-r--r-- | arch/x86/kernel/relocate_kernel_64.S | 4 |
3 files changed, 5 insertions, 5 deletions
diff --git a/arch/x86/boot/boot.h b/arch/x86/boot/boot.h index 38f17a1e1e36..f899717f9e48 100644 --- a/arch/x86/boot/boot.h +++ b/arch/x86/boot/boot.h @@ -34,7 +34,7 @@ extern struct setup_header hdr; extern struct boot_params boot_params; -#define cpu_relax() asm volatile("rep; nop") +#define cpu_relax() asm volatile("pause") static inline void io_delay(void) { diff --git a/arch/x86/include/asm/vdso/processor.h b/arch/x86/include/asm/vdso/processor.h index c9b2ba7a9ec4..240d761b8ce4 100644 --- a/arch/x86/include/asm/vdso/processor.h +++ b/arch/x86/include/asm/vdso/processor.h @@ -7,10 +7,10 @@ #ifndef __ASSEMBLER__ -/* REP NOP (PAUSE) is a good thing to insert into busy-wait loops. */ +/* PAUSE is a good thing to insert into busy-wait loops. */ static __always_inline void rep_nop(void) { - asm volatile("rep; nop" ::: "memory"); + asm volatile("pause" ::: "memory"); } static __always_inline void cpu_relax(void) diff --git a/arch/x86/kernel/relocate_kernel_64.S b/arch/x86/kernel/relocate_kernel_64.S index 1d6355227bf6..ea604f4d0b52 100644 --- a/arch/x86/kernel/relocate_kernel_64.S +++ b/arch/x86/kernel/relocate_kernel_64.S @@ -405,7 +405,7 @@ SYM_CODE_START_LOCAL_NOALIGN(pr_char_8250) inb %dx, %al testb $XMTRDY, %al jnz .Lready - rep nop + pause jmp .Lxmtrdy_loop .Lready: @@ -426,7 +426,7 @@ SYM_CODE_START_LOCAL_NOALIGN(pr_char_8250_mmio32) movb (LSR*4)(%rdx), %ah testb $XMTRDY, %ah jnz .Lready_mmio - rep nop + pause jmp .Lxmtrdy_loop_mmio .Lready_mmio: |