2020-08-06 06:02:41

by Christophe Leroy

Subject: [PATCH] powerpc/32s: Fix assembler warning about r0

The assembler says:
arch/powerpc/kernel/head_32.S:1095: Warning: invalid register expression

It's objecting to the use of r0 as the RA argument. That's because
when RA = 0 the literal value 0 is used, rather than the content of
r0, making the use of r0 in the source potentially confusing.

Fix it to use a literal 0, the generated code is identical.

Signed-off-by: Christophe Leroy <[email protected]>
---
arch/powerpc/kernel/head_32.S | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S
index f3ab94d73936..5624db0e09a1 100644
--- a/arch/powerpc/kernel/head_32.S
+++ b/arch/powerpc/kernel/head_32.S
@@ -1092,7 +1092,7 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_HPTE_TABLE)
*/
lis r5, abatron_pteptrs@h
ori r5, r5, abatron_pteptrs@l
- stw r5, 0xf0(r0) /* This much match your Abatron config */
+ stw r5, 0xf0(0) /* This much match your Abatron config */
lis r6, swapper_pg_dir@h
ori r6, r6, swapper_pg_dir@l
tophys(r5, r5)
--
2.25.0

2020-09-09 16:37:49

by Michael Ellerman

Subject: Re: [PATCH] powerpc/32s: Fix assembler warning about r0

On Thu, 6 Aug 2020 06:01:42 +0000 (UTC), Christophe Leroy wrote:
> The assembler says:
> arch/powerpc/kernel/head_32.S:1095: Warning: invalid register expression
>
> It's objecting to the use of r0 as the RA argument. That's because
> when RA = 0 the literal value 0 is used, rather than the content of
> r0, making the use of r0 in the source potentially confusing.
>
> [...]

Applied to powerpc/next.

[1/1] powerpc/32s: Fix assembler warning about r0
https://git.kernel.org/powerpc/c/b51ba4fe2e134b631f9c8f45423707aab71449b5

cheers