* [PATCH 1/2] powerpc: add enable_kernel_fp() stub for ALTIVEC without PPC_FPU
@ 2021-04-18 20:17 Randy Dunlap
2021-04-18 20:17 ` [PATCH 2/2] powerpc: add ALTIVEC support to lib/ when PPC_FPU not set Randy Dunlap
0 siblings, 1 reply; 5+ messages in thread
From: Randy Dunlap @ 2021-04-18 20:17 UTC (permalink / raw)
To: linux-kernel
Cc: Randy Dunlap, kernel test robot, Michael Ellerman, linuxppc-dev,
Christophe Leroy, Segher Boessenkool
On a kernel config with ALTIVEC=y and PPC_FPU not set/enabled,
there is a build error:
drivers/cpufreq/pmac32-cpufreq.c:262:2: error: implicit declaration of function 'enable_kernel_fp' [-Werror,-Wimplicit-function-declaration]
enable_kernel_fp();
so add a stub function for that when PPC_FPU is not set.
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: kernel test robot <lkp@intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Segher Boessenkool <segher@kernel.crashing.org>
Cc: lkp@intel.com
---
arch/powerpc/include/asm/switch_to.h | 1 +
1 file changed, 1 insertion(+)
--- linux-next-20210416.orig/arch/powerpc/include/asm/switch_to.h
+++ linux-next-20210416/arch/powerpc/include/asm/switch_to.h
@@ -48,6 +48,7 @@ static inline void disable_kernel_fp(voi
#else
static inline void save_fpu(struct task_struct *t) { }
static inline void flush_fp_to_thread(struct task_struct *t) { }
+static inline void enable_kernel_fp(void) { }
#endif
#ifdef CONFIG_ALTIVEC
^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH 2/2] powerpc: add ALTIVEC support to lib/ when PPC_FPU not set
2021-04-18 20:17 [PATCH 1/2] powerpc: add enable_kernel_fp() stub for ALTIVEC without PPC_FPU Randy Dunlap
@ 2021-04-18 20:17 ` Randy Dunlap
2021-04-19 13:32 ` Segher Boessenkool
0 siblings, 1 reply; 5+ messages in thread
From: Randy Dunlap @ 2021-04-18 20:17 UTC (permalink / raw)
To: linux-kernel
Cc: Randy Dunlap, kernel test robot, Michael Ellerman, linuxppc-dev,
Christophe Leroy, Segher Boessenkool
When PPC_FPU is not set and ALTIVEC=y, arch/powerpc/lib/ldstfp.c is not
being built, but it is also needed when ALTIVEC=y for get_vr() and
put_vr().
../arch/powerpc/lib/sstep.c: In function 'do_vec_load':
../arch/powerpc/lib/sstep.c:637:3: error: implicit declaration of function 'put_vr' [-Werror=implicit-function-declaration]
637 | put_vr(rn, &u.v);
| ^~~~~~
../arch/powerpc/lib/sstep.c: In function 'do_vec_store':
../arch/powerpc/lib/sstep.c:660:3: error: implicit declaration of function 'get_vr'; did you mean 'get_oc'? [-Werror=implicit-function-declaration]
660 | get_vr(rn, &u.v);
| ^~~~~~
Add ldstfp.o to the Makefile for CONFIG_ALTIVEC and add
externs for get_vr() and put_vr() in lib/sstep.c to fix the
build errors.
This was seen in a kernel config from kernel test robot <lkp@intel.com>
that reported a different build issue (for pmac32-cpufreq.c).
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Segher Boessenkool <segher@kernel.crashing.org>
Cc: lkp@intel.com
---
arch/powerpc/lib/Makefile | 1 +
arch/powerpc/lib/sstep.c | 5 +++++
2 files changed, 6 insertions(+)
--- linux-next-20210416.orig/arch/powerpc/lib/Makefile
+++ linux-next-20210416/arch/powerpc/lib/Makefile
@@ -54,6 +54,7 @@ obj-y += checksum_$(BITS).o checksum_w
obj-y += sstep.o
obj-$(CONFIG_PPC_FPU) += ldstfp.o
+obj-$(CONFIG_ALTIVEC) += ldstfp.o
obj64-y += quad.o
obj-$(CONFIG_PPC_LIB_RHEAP) += rheap.o
--- linux-next-20210416.orig/arch/powerpc/lib/sstep.c
+++ linux-next-20210416/arch/powerpc/lib/sstep.c
@@ -50,6 +50,11 @@ extern void conv_sp_to_dp(const float *s
extern void conv_dp_to_sp(const double *dp, float *sp);
#endif
+#ifdef CONFIG_ALTIVEC
+extern void get_vr(int rn, __vector128 *p);
+extern void put_vr(int rn, __vector128 *p);
+#endif /* CONFIG_ALTIVEC */
+
#ifdef __powerpc64__
/*
* Functions in quad.S
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH 2/2] powerpc: add ALTIVEC support to lib/ when PPC_FPU not set
2021-04-18 20:17 ` [PATCH 2/2] powerpc: add ALTIVEC support to lib/ when PPC_FPU not set Randy Dunlap
@ 2021-04-19 13:32 ` Segher Boessenkool
2021-04-19 13:38 ` Christophe Leroy
0 siblings, 1 reply; 5+ messages in thread
From: Segher Boessenkool @ 2021-04-19 13:32 UTC (permalink / raw)
To: Randy Dunlap
Cc: linux-kernel, kernel test robot, Michael Ellerman, linuxppc-dev,
Christophe Leroy
Hi!
On Sun, Apr 18, 2021 at 01:17:26PM -0700, Randy Dunlap wrote:
> Add ldstfp.o to the Makefile for CONFIG_ALTIVEC and add
> externs for get_vr() and put_vr() in lib/sstep.c to fix the
> build errors.
> obj-$(CONFIG_PPC_FPU) += ldstfp.o
> +obj-$(CONFIG_ALTIVEC) += ldstfp.o
It is probably a good idea to split ldstfp.S into two, one for each of
the two configuration options?
Segher
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH 2/2] powerpc: add ALTIVEC support to lib/ when PPC_FPU not set
2021-04-19 13:32 ` Segher Boessenkool
@ 2021-04-19 13:38 ` Christophe Leroy
2021-04-19 13:57 ` Segher Boessenkool
0 siblings, 1 reply; 5+ messages in thread
From: Christophe Leroy @ 2021-04-19 13:38 UTC (permalink / raw)
To: Segher Boessenkool, Randy Dunlap
Cc: linux-kernel, kernel test robot, Michael Ellerman, linuxppc-dev
Le 19/04/2021 à 15:32, Segher Boessenkool a écrit :
> Hi!
>
> On Sun, Apr 18, 2021 at 01:17:26PM -0700, Randy Dunlap wrote:
>> Add ldstfp.o to the Makefile for CONFIG_ALTIVEC and add
>> externs for get_vr() and put_vr() in lib/sstep.c to fix the
>> build errors.
>
>> obj-$(CONFIG_PPC_FPU) += ldstfp.o
>> +obj-$(CONFIG_ALTIVEC) += ldstfp.o
>
> It is probably a good idea to split ldstfp.S into two, one for each of
> the two configuration options?
>
Or we can build it all the time and #ifdef the FPU part.
Because it contains FPU, ALTIVEC and VSX stuff.
Christophe
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH 2/2] powerpc: add ALTIVEC support to lib/ when PPC_FPU not set
2021-04-19 13:38 ` Christophe Leroy
@ 2021-04-19 13:57 ` Segher Boessenkool
0 siblings, 0 replies; 5+ messages in thread
From: Segher Boessenkool @ 2021-04-19 13:57 UTC (permalink / raw)
To: Christophe Leroy
Cc: Randy Dunlap, linux-kernel, kernel test robot, Michael Ellerman,
linuxppc-dev
On Mon, Apr 19, 2021 at 03:38:02PM +0200, Christophe Leroy wrote:
> Le 19/04/2021 à 15:32, Segher Boessenkool a écrit :
> >On Sun, Apr 18, 2021 at 01:17:26PM -0700, Randy Dunlap wrote:
> >>Add ldstfp.o to the Makefile for CONFIG_ALTIVEC and add
> >>externs for get_vr() and put_vr() in lib/sstep.c to fix the
> >>build errors.
> >
> >> obj-$(CONFIG_PPC_FPU) += ldstfp.o
> >>+obj-$(CONFIG_ALTIVEC) += ldstfp.o
> >
> >It is probably a good idea to split ldstfp.S into two, one for each of
> >the two configuration options?
> >
>
> Or we can build it all the time and #ifdef the FPU part.
>
> Because it contains FPU, ALTIVEC and VSX stuff.
So it becomes an empty object file if none of the options are selected?
Good idea :-)
Segher
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2021-04-19 14:01 UTC | newest]
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2021-04-18 20:17 [PATCH 1/2] powerpc: add enable_kernel_fp() stub for ALTIVEC without PPC_FPU Randy Dunlap
2021-04-18 20:17 ` [PATCH 2/2] powerpc: add ALTIVEC support to lib/ when PPC_FPU not set Randy Dunlap
2021-04-19 13:32 ` Segher Boessenkool
2021-04-19 13:38 ` Christophe Leroy
2021-04-19 13:57 ` Segher Boessenkool
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