[PATCH] riscv: remove redundant mv instructions

Nam Cao posted 1 patch 2 years, 6 months ago
arch/riscv/kernel/head.S | 6 +-----
1 file changed, 1 insertion(+), 5 deletions(-)
[PATCH] riscv: remove redundant mv instructions
Posted by Nam Cao 2 years, 6 months ago
Some mv instructions were useful when first introduced to preserve a0 and
a1 before function calls. However the code has changed and they are now
redundant. Remove them.

Signed-off-by: Nam Cao <namcaov@gmail.com>
---
 arch/riscv/kernel/head.S | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S
index 11c3b94c4534..3710ea5d160f 100644
--- a/arch/riscv/kernel/head.S
+++ b/arch/riscv/kernel/head.S
@@ -289,10 +289,6 @@ clear_bss:
 	blt a3, a4, clear_bss
 clear_bss_done:
 #endif
-	/* Save hart ID and DTB physical address */
-	mv s0, a0
-	mv s1, a1
-
 	la a2, boot_cpu_hartid
 	XIP_FIXUP_OFFSET a2
 	REG_S a0, (a2)
@@ -306,7 +302,7 @@ clear_bss_done:
 	la a0, __dtb_start
 	XIP_FIXUP_OFFSET a0
 #else
-	mv a0, s1
+	mv a0, a1
 #endif /* CONFIG_BUILTIN_DTB */
 	call setup_vm
 #ifdef CONFIG_MMU
-- 
2.34.1
Re: [PATCH] riscv: remove redundant mv instructions
Posted by Palmer Dabbelt 2 years, 5 months ago
On Tue, 25 Jul 2023 07:38:35 +0200, Nam Cao wrote:
> Some mv instructions were useful when first introduced to preserve a0 and
> a1 before function calls. However the code has changed and they are now
> redundant. Remove them.
> 
> 

Applied, thanks!

[1/1] riscv: remove redundant mv instructions
      https://git.kernel.org/palmer/c/10f763532d58

Best regards,
-- 
Palmer Dabbelt <palmer@rivosinc.com>
Re: [PATCH] riscv: remove redundant mv instructions
Posted by patchwork-bot+linux-riscv@kernel.org 2 years, 5 months ago
Hello:

This patch was applied to riscv/linux.git (for-next)
by Palmer Dabbelt <palmer@rivosinc.com>:

On Tue, 25 Jul 2023 07:38:35 +0200 you wrote:
> Some mv instructions were useful when first introduced to preserve a0 and
> a1 before function calls. However the code has changed and they are now
> redundant. Remove them.
> 
> Signed-off-by: Nam Cao <namcaov@gmail.com>
> ---
>  arch/riscv/kernel/head.S | 6 +-----
>  1 file changed, 1 insertion(+), 5 deletions(-)

Here is the summary with links:
  - riscv: remove redundant mv instructions
    https://git.kernel.org/riscv/c/10f763532d58

You are awesome, thank you!
-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html
Re: [PATCH] riscv: remove redundant mv instructions
Posted by Alexandre Ghiti 2 years, 6 months ago
Hi Nam,


On 25/07/2023 07:38, Nam Cao wrote:
> Some mv instructions were useful when first introduced to preserve a0 and
> a1 before function calls. However the code has changed and they are now
> redundant. Remove them.
>
> Signed-off-by: Nam Cao <namcaov@gmail.com>
> ---
>   arch/riscv/kernel/head.S | 6 +-----
>   1 file changed, 1 insertion(+), 5 deletions(-)
>
> diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S
> index 11c3b94c4534..3710ea5d160f 100644
> --- a/arch/riscv/kernel/head.S
> +++ b/arch/riscv/kernel/head.S
> @@ -289,10 +289,6 @@ clear_bss:
>   	blt a3, a4, clear_bss
>   clear_bss_done:
>   #endif
> -	/* Save hart ID and DTB physical address */
> -	mv s0, a0
> -	mv s1, a1
> -
>   	la a2, boot_cpu_hartid
>   	XIP_FIXUP_OFFSET a2
>   	REG_S a0, (a2)
> @@ -306,7 +302,7 @@ clear_bss_done:
>   	la a0, __dtb_start
>   	XIP_FIXUP_OFFSET a0
>   #else
> -	mv a0, s1
> +	mv a0, a1
>   #endif /* CONFIG_BUILTIN_DTB */
>   	call setup_vm
>   #ifdef CONFIG_MMU


You can add:

Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>

Thanks,

Alex