From: Brian Gerst <brgerst@gmail.com>
To: linux-kernel@vger.kernel.org, x86@kernel.org
Cc: Ingo Molnar <mingo@kernel.org>, "H . Peter Anvin" <hpa@zytor.com>,
Thomas Gleixner <tglx@linutronix.de>,
Borislav Petkov <bp@alien8.de>, Ard Biesheuvel <ardb@kernel.org>,
"Rafael J . Wysocki" <rafael@kernel.org>,
Len Brown <lenb@kernel.org>, Pavel Machek <pavel@kernel.org>,
Brian Gerst <brgerst@gmail.com>
Subject: [PATCH v2 4/4] x86/acpi/suspend: Remove redundant register saves
Date: Tue, 3 Feb 2026 12:58:21 -0500 [thread overview]
Message-ID: <20260203175821.511847-5-brgerst@gmail.com> (raw)
In-Reply-To: <20260203175821.511847-1-brgerst@gmail.com>
All general purpose registers are saved in save_context. Remove the
redundant saves to local data.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
---
arch/x86/kernel/acpi/wakeup_64.S | 19 +------------------
1 file changed, 1 insertion(+), 18 deletions(-)
diff --git a/arch/x86/kernel/acpi/wakeup_64.S b/arch/x86/kernel/acpi/wakeup_64.S
index b4bb1ca228b6..e8b3d01ba14a 100644
--- a/arch/x86/kernel/acpi/wakeup_64.S
+++ b/arch/x86/kernel/acpi/wakeup_64.S
@@ -25,19 +25,12 @@ SYM_FUNC_START(wakeup_long64)
movq saved_magic(%rip), %rax
movq $0x123456789abcdef0, %rdx
cmpq %rdx, %rax
- je 2f
+ je .Lresume_point
/* stop here on a saved_magic mismatch */
movq $0xbad6d61676963, %rcx
1:
jmp 1b
-2:
- movq saved_rbx(%rip), %rbx
- movq saved_rdi(%rip), %rdi
- movq saved_rsi(%rip), %rsi
- movq saved_rbp(%rip), %rbp
-
- jmp .Lresume_point
SYM_FUNC_END(wakeup_long64)
STACK_FRAME_NON_STANDARD wakeup_long64
@@ -67,11 +60,6 @@ SYM_FUNC_START(do_suspend_lowlevel)
movq PER_CPU_VAR(current_task), %rax
movq %rsp, TASK_threadsp(%rax)
- movq %rbp, saved_rbp(%rip)
- movq %rbx, saved_rbx(%rip)
- movq %rdi, saved_rdi(%rip)
- movq %rsi, saved_rsi(%rip)
-
movl $3, %edi
xorl %eax, %eax
call x86_acpi_enter_sleep_state
@@ -120,9 +108,4 @@ SYM_FUNC_START(do_suspend_lowlevel)
SYM_FUNC_END(do_suspend_lowlevel)
.data
-saved_rbp: .quad 0
-saved_rsi: .quad 0
-saved_rdi: .quad 0
-saved_rbx: .quad 0
-
SYM_DATA(saved_magic, .quad 0)
--
2.52.0
next prev parent reply other threads:[~2026-02-03 17:59 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-03 17:58 [PATCH v2 0/4] x86 suspend cleanups Brian Gerst
2026-02-03 17:58 ` [PATCH v2 1/4] x86/acpi/suspend: Remove indirect jump Brian Gerst
2026-02-03 17:58 ` [PATCH v2 2/4] x86/acpi/suspend: Remove segment reloads on resume Brian Gerst
2026-02-03 17:58 ` [PATCH v2 3/4] x86/acpi/suspend: Clean up stack usage Brian Gerst
2026-02-03 17:58 ` Brian Gerst [this message]
2026-02-03 20:31 ` [PATCH v2 0/4] x86 suspend cleanups Rafael J. Wysocki
2026-02-04 9:47 ` Ard Biesheuvel
2026-02-07 18:04 ` Brian Gerst
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