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Subject[tip: x86/percpu] x86/acpi: Use %rip-relative addressing in wakeup_64.S
The following commit has been merged into the x86/percpu branch of tip:

Commit-ID: 0978d64f9406122c369d5f46e1eb855646f6c32c
Gitweb: https://git.kernel.org/tip/0978d64f9406122c369d5f46e1eb855646f6c32c
Author: Uros Bizjak <ubizjak@gmail.com>
AuthorDate: Fri, 03 Nov 2023 11:48:22 +01:00
Committer: Ingo Molnar <mingo@kernel.org>
CommitterDate: Thu, 30 Nov 2023 20:09:49 +01:00

x86/acpi: Use %rip-relative addressing in wakeup_64.S

This is a "nice-to-have" change with minor code generation benefits:

- Instruction with %rip-relative address operand is one byte shorter than
its absolute address counterpart,

- it is also compatible with position independent executable (-fpie) builds,

- it is also consistent with what the compiler emits by default when
a symbol is accessed.

No functional changes intended.

Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/20231103104900.409470-1-ubizjak@gmail.com
---
arch/x86/kernel/acpi/wakeup_64.S | 24 ++++++++++++------------
1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/arch/x86/kernel/acpi/wakeup_64.S b/arch/x86/kernel/acpi/wakeup_64.S
index d5d8a35..94ff83f 100644
--- a/arch/x86/kernel/acpi/wakeup_64.S
+++ b/arch/x86/kernel/acpi/wakeup_64.S
@@ -17,7 +17,7 @@
* Hooray, we are in Long 64-bit mode (but still running in low memory)
*/
SYM_FUNC_START(wakeup_long64)
- movq saved_magic, %rax
+ movq saved_magic(%rip), %rax
movq $0x123456789abcdef0, %rdx
cmpq %rdx, %rax
je 2f
@@ -33,14 +33,14 @@ SYM_FUNC_START(wakeup_long64)
movw %ax, %es
movw %ax, %fs
movw %ax, %gs
- movq saved_rsp, %rsp
+ movq saved_rsp(%rip), %rsp

- movq saved_rbx, %rbx
- movq saved_rdi, %rdi
- movq saved_rsi, %rsi
- movq saved_rbp, %rbp
+ movq saved_rbx(%rip), %rbx
+ movq saved_rdi(%rip), %rdi
+ movq saved_rsi(%rip), %rsi
+ movq saved_rbp(%rip), %rbp

- movq saved_rip, %rax
+ movq saved_rip(%rip), %rax
ANNOTATE_RETPOLINE_SAFE
jmp *%rax
SYM_FUNC_END(wakeup_long64)
@@ -72,11 +72,11 @@ SYM_FUNC_START(do_suspend_lowlevel)

movq $.Lresume_point, saved_rip(%rip)

- movq %rsp, saved_rsp
- movq %rbp, saved_rbp
- movq %rbx, saved_rbx
- movq %rdi, saved_rdi
- movq %rsi, saved_rsi
+ movq %rsp, saved_rsp(%rip)
+ movq %rbp, saved_rbp(%rip)
+ movq %rbx, saved_rbx(%rip)
+ movq %rdi, saved_rdi(%rip)
+ movq %rsi, saved_rsi(%rip)

addq $8, %rsp
movl $3, %edi
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