powerpc/40x: Fix assembler warning about r0

The assembler says:
  arch/powerpc/kernel/head_40x.S:623: 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: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200722022422.825197-1-mpe@ellerman.id.au

diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S
index 926bfa7..5b282d9 100644 (file)
--- a/arch/powerpc/kernel/head_40x.S
+++ b/arch/powerpc/kernel/head_40x.S
@@ -620,7 +620,7 @@ start_here:
        ori     r6, r6, swapper_pg_dir@l
        lis     r5, abatron_pteptrs@h
        ori     r5, r5, abatron_pteptrs@l
        ori     r6, r6, swapper_pg_dir@l
        lis     r5, abatron_pteptrs@h
        ori     r5, r5, abatron_pteptrs@l

-       stw     r5, 0xf0(r0)    /* Must match your Abatron config file */
+       stw     r5, 0xf0(0)     /* Must match your Abatron config file */

        tophys(r5,r5)
        stw     r6, 0(r5)
 
        tophys(r5,r5)
        stw     r6, 0(r5)