| Message ID | 20200722022422.825197-1-mpe@ellerman.id.au (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 8d8a629d00a5283874b81b594f31f8d436dc57d8 |
| Headers | show |
| Series | powerpc/40x: Fix assembler warning about r0 | expand |
On Wed, 22 Jul 2020 12:24:22 +1000, Michael Ellerman wrote: > 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. > > [...] Applied to powerpc/next. [1/1] powerpc/40x: Fix assembler warning about r0 https://git.kernel.org/powerpc/c/8d8a629d00a5283874b81b594f31f8d436dc57d8 cheers
Le 22/07/2020 à 04:24, Michael Ellerman a écrit : > The assembler says: > arch/powerpc/kernel/head_40x.S:623: Warning: invalid register expression I get exactly the same with head_32.S, for the exact same reason. Christophe > > 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> > --- > arch/powerpc/kernel/head_40x.S | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S > index 926bfa73586a..5b282d9965a5 100644 > --- a/arch/powerpc/kernel/head_40x.S > +++ b/arch/powerpc/kernel/head_40x.S > @@ -620,7 +620,7 @@ _ENTRY(saved_ksp_limit) > 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) > >
Christophe Leroy <christophe.leroy@csgroup.eu> writes: > Le 22/07/2020 à 04:24, Michael Ellerman a écrit : >> The assembler says: >> arch/powerpc/kernel/head_40x.S:623: Warning: invalid register expression > > I get exactly the same with head_32.S, for the exact same reason. Ah yep, I see it. I mostly build pmac32_defconfig which doesn't have BDI_SWITCH enabled. Send a patch? :) Do we still need the BDI_SWITCH code? Is it likely anyone still has one, that works? cheers
Le 06/08/2020 à 04:18, Michael Ellerman a écrit : > Christophe Leroy <christophe.leroy@csgroup.eu> writes: >> Le 22/07/2020 à 04:24, Michael Ellerman a écrit : >>> The assembler says: >>> arch/powerpc/kernel/head_40x.S:623: Warning: invalid register expression >> >> I get exactly the same with head_32.S, for the exact same reason. > > Ah yep, I see it. I mostly build pmac32_defconfig which doesn't have > BDI_SWITCH enabled. > > Send a patch? :) Done. > > Do we still need the BDI_SWITCH code? Is it likely anyone still has one, > that works? I have three (One for 83xx and two for 8xx) and they work, allthough I'm using them only for Uboot and for very very very early Linux boot debugging (Last time I used it with Linux was when implementing KASAN) Christophe
Christophe Leroy <christophe.leroy@csgroup.eu> writes: > Le 06/08/2020 à 04:18, Michael Ellerman a écrit : >> Christophe Leroy <christophe.leroy@csgroup.eu> writes: >>> Le 22/07/2020 à 04:24, Michael Ellerman a écrit : >>>> The assembler says: >>>> arch/powerpc/kernel/head_40x.S:623: Warning: invalid register expression >>> >>> I get exactly the same with head_32.S, for the exact same reason. >> >> Ah yep, I see it. I mostly build pmac32_defconfig which doesn't have >> BDI_SWITCH enabled. >> >> Send a patch? :) > > Done. > >> >> Do we still need the BDI_SWITCH code? Is it likely anyone still has one, >> that works? > > I have three (One for 83xx and two for 8xx) and they work, allthough I'm > using them only for Uboot and for very very very early Linux boot > debugging (Last time I used it with Linux was when implementing KASAN) OK, happy to keep the code around if it works and is being used, even just a little bit. cheers
diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S index 926bfa73586a..5b282d9965a5 100644 --- a/arch/powerpc/kernel/head_40x.S +++ b/arch/powerpc/kernel/head_40x.S @@ -620,7 +620,7 @@ _ENTRY(saved_ksp_limit) 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)
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> --- arch/powerpc/kernel/head_40x.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)