[RFC][PATCH] powerpc/CoreNet64: compile with CONFIG_E{5, 6}500_CPU well

CONFIG_ALTIVEC is always enabled for CoreNet64. And if we
select CONFIG_E{5,6}500_CPU this may introduce -mcpu=e500mc64
into $CFLAGS. But Altivec and Spe options not allowed with
e500mc64, so :

  CC      arch/powerpc/lib/xor_vmx.o
arch/powerpc/lib/xor_vmx.c:1:0: error: AltiVec not supported in this target
make[1]: *** [arch/powerpc/lib/xor_vmx.o] Error 1
make: *** [arch/powerpc/lib] Error 2

Signed-off-by: Tiejun Chen <redacted>
---
 arch/powerpc/lib/Makefile |    3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/powerpc/lib/Makefile b/arch/powerpc/lib/Makefile
index 95a20e1..641a77d 100644
--- a/arch/powerpc/lib/Makefile
+++ b/arch/powerpc/lib/Makefile

@@ -40,5 +40,8 @@ obj-y			+= code-patching.o
 obj-y			+= feature-fixups.o
 obj-$(CONFIG_FTR_FIXUP_SELFTEST) += feature-fixups-test.o
 
+# Altivec and Spe options not allowed with e500mc64 in GCC.
+ifeq ($(call cc-option-yn,-mcpu=e500mc64),n)
 obj-$(CONFIG_ALTIVEC)	+= xor_vmx.o
 CFLAGS_xor_vmx.o += -maltivec -mabi=altivec
+endif

-- 
1.7.9.5

On Wed, 2013-11-20 at 16:35 +0800, Tiejun Chen wrote:

CONFIG_ALTIVEC is always enabled for CoreNet64.

In the defconfig perhaps, but this isn't a generally true statement.

And if we select CONFIG_E{5,6}500_CPU this may introduce -mcpu=e500mc64
into $CFLAGS. But Altivec and Spe options not allowed with
e500mc64, so :

Sigh.

This does not seem like the right fix.  What if GCC supports both
-mcpu=e500mc64 and -mcpu=e6500, and we're using the latter?  Or for that
matter, if we're using -mcpu=whatever-ibm-chip-has-this?

Plus, wouldn't you need to do something to prevent code in that file
from being called?

-Scott

On Nov 20, 2013, at 10:41 AM, Scott Wood [off-list ref] =
wrote:

On Wed, 2013-11-20 at 16:35 +0800, Tiejun Chen wrote:

quoted

CONFIG_ALTIVEC is always enabled for CoreNet64.

=20
In the defconfig perhaps, but this isn't a generally true statement.
=20

quoted

And if we select CONFIG_E{5,6}500_CPU this may introduce =

-mcpu=3De500mc64

quoted

into $CFLAGS. But Altivec and Spe options not allowed with
e500mc64, so :

=20
Sigh.
=20

quoted

 CC      arch/powerpc/lib/xor_vmx.o
arch/powerpc/lib/xor_vmx.c:1:0: error: AltiVec not supported in this =

target

quoted

make[1]: *** [arch/powerpc/lib/xor_vmx.o] Error 1
make: *** [arch/powerpc/lib] Error 2
=20
Signed-off-by: Tiejun Chen <redacted>
---
arch/powerpc/lib/Makefile |    3 +++
1 file changed, 3 insertions(+)
=20

diff --git a/arch/powerpc/lib/Makefile b/arch/powerpc/lib/Makefile
index 95a20e1..641a77d 100644
--- a/arch/powerpc/lib/Makefile
+++ b/arch/powerpc/lib/Makefile

@@ -40,5 +40,8 @@ obj-y			+=3D code-patching.o

obj-y			+=3D feature-fixups.o
obj-$(CONFIG_FTR_FIXUP_SELFTEST) +=3D feature-fixups-test.o
=20
+# Altivec and Spe options not allowed with e500mc64 in GCC.
+ifeq ($(call cc-option-yn,-mcpu=3De500mc64),n)
obj-$(CONFIG_ALTIVEC)	+=3D xor_vmx.o
CFLAGS_xor_vmx.o +=3D -maltivec -mabi=3Daltivec
+endif

=20
This does not seem like the right fix.  What if GCC supports both
-mcpu=3De500mc64 and -mcpu=3De6500, and we're using the latter?  Or =

for that

matter, if we're using -mcpu=3Dwhatever-ibm-chip-has-this?
=20
Plus, wouldn't you need to do something to prevent code in that file
from being called?
=20
-Scott

Why does -mcpu=3De500mc64 get you spe enabled?  It shouldn=92t as no =
e500mc or greater part has spe.  Can you try using -mno-spe -maltivec?

- k=

On Wed, 2013-11-20 at 12:47 -0600, Kumar Gala wrote:

On Nov 20, 2013, at 10:41 AM, Scott Wood [off-list ref] wrot=

e:

=20

quoted

On Wed, 2013-11-20 at 16:35 +0800, Tiejun Chen wrote:

quoted

CONFIG_ALTIVEC is always enabled for CoreNet64.

=20
In the defconfig perhaps, but this isn't a generally true statement.
=20

quoted

And if we select CONFIG_E{5,6}500_CPU this may introduce -mcpu=3De50=

0mc64

quoted

quoted

into $CFLAGS. But Altivec and Spe options not allowed with
e500mc64, so :

=20
Sigh.
=20

quoted

 CC      arch/powerpc/lib/xor_vmx.o
arch/powerpc/lib/xor_vmx.c:1:0: error: AltiVec not supported in this=

 target

quoted

quoted

make[1]: *** [arch/powerpc/lib/xor_vmx.o] Error 1
make: *** [arch/powerpc/lib] Error 2
=20
Signed-off-by: Tiejun Chen <redacted>
---
arch/powerpc/lib/Makefile |    3 +++
1 file changed, 3 insertions(+)
=20

diff --git a/arch/powerpc/lib/Makefile b/arch/powerpc/lib/Makefile
index 95a20e1..641a77d 100644
--- a/arch/powerpc/lib/Makefile
+++ b/arch/powerpc/lib/Makefile

@@ -40,5 +40,8 @@ obj-y			+=3D code-patching.o

obj-y			+=3D feature-fixups.o
obj-$(CONFIG_FTR_FIXUP_SELFTEST) +=3D feature-fixups-test.o
=20
+# Altivec and Spe options not allowed with e500mc64 in GCC.
+ifeq ($(call cc-option-yn,-mcpu=3De500mc64),n)
obj-$(CONFIG_ALTIVEC)	+=3D xor_vmx.o
CFLAGS_xor_vmx.o +=3D -maltivec -mabi=3Daltivec
+endif

=20
This does not seem like the right fix.  What if GCC supports both
-mcpu=3De500mc64 and -mcpu=3De6500, and we're using the latter?  Or f=

or that

quoted

matter, if we're using -mcpu=3Dwhatever-ibm-chip-has-this?
=20
Plus, wouldn't you need to do something to prevent code in that file
from being called?
=20
-Scott

=20
Why does -mcpu=3De500mc64 get you spe enabled?  It shouldn=E2=80=99t as=

 no e500mc or greater part has spe.  Can you try using -mno-spe -maltivec=
?

I don't think SPE is relevant.  The problem is that GCC refuses to allow
-maltivec to be combined with -mcpu=3De500mc64.  -mno-spe doesn't make a
difference.

-Scott

On 11/21/2013 12:41 AM, Scott Wood wrote:

On Wed, 2013-11-20 at 16:35 +0800, Tiejun Chen wrote:

quoted

CONFIG_ALTIVEC is always enabled for CoreNet64.

In the defconfig perhaps, but this isn't a generally true statement.

Yes, but I think we should avoid this probable scenario :)

quoted

And if we select CONFIG_E{5,6}500_CPU this may introduce -mcpu=e500mc64
into $CFLAGS. But Altivec and Spe options not allowed with
e500mc64, so :

Sigh.

quoted

   CC      arch/powerpc/lib/xor_vmx.o
arch/powerpc/lib/xor_vmx.c:1:0: error: AltiVec not supported in this target
make[1]: *** [arch/powerpc/lib/xor_vmx.o] Error 1
make: *** [arch/powerpc/lib] Error 2

Signed-off-by: Tiejun Chen <redacted>
---
  arch/powerpc/lib/Makefile |    3 +++
  1 file changed, 3 insertions(+)

diff --git a/arch/powerpc/lib/Makefile b/arch/powerpc/lib/Makefile
index 95a20e1..641a77d 100644
--- a/arch/powerpc/lib/Makefile
+++ b/arch/powerpc/lib/Makefile

@@ -40,5 +40,8 @@ obj-y			+= code-patching.o
  obj-y			+= feature-fixups.o
  obj-$(CONFIG_FTR_FIXUP_SELFTEST) += feature-fixups-test.o

+# Altivec and Spe options not allowed with e500mc64 in GCC.
+ifeq ($(call cc-option-yn,-mcpu=e500mc64),n)
  obj-$(CONFIG_ALTIVEC)	+= xor_vmx.o
  CFLAGS_xor_vmx.o += -maltivec -mabi=altivec
+endif

This does not seem like the right fix.  What if GCC supports both
-mcpu=e500mc64 and -mcpu=e6500, and we're using the latter?  Or for that

I can understand what you mean, but in current kernel, -mcpu=e500mc64 should be 
excluded from -mcpu=e6500,

arch/powerpc/Makefile:

E5500_CPU := $(call cc-option,-mcpu=e500mc64,-mcpu=powerpc64)
CFLAGS-$(CONFIG_E5500_CPU) += $(E5500_CPU)
CFLAGS-$(CONFIG_E6500_CPU) += $(call cc-option,-mcpu=e6500,$(E5500_CPU))

But unfortunately, another place also use the same option,

lib/raid6/Makefile:

raid6_pq-$(CONFIG_ALTIVEC) += altivec1.o altivec2.o altivec4.o altivec8.o
...
ifeq ($(CONFIG_ALTIVEC),y)
altivec_flags := -maltivec -mabi=altivec
endif

Looks we have to do something in this common Makefile file as well, but it may 
be a bit ugly if still judge some cpu-specific flags...

So what about this version?

diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
index 607acf5..872a85c 100644
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile

@@ -127,7 +127,12 @@ CFLAGS-$(CONFIG_POWER5_CPU) += $(call cc-option,-mcpu=power5)
  CFLAGS-$(CONFIG_POWER6_CPU) += $(call cc-option,-mcpu=power6)
  CFLAGS-$(CONFIG_POWER7_CPU) += $(call cc-option,-mcpu=power7)

+# Altivec and Spe options not allowed with e500mc64 in GCC.
+ifeq ($(CONFIG_ALTIVEC),)
  E5500_CPU := $(call cc-option,-mcpu=e500mc64,-mcpu=powerpc64)
+else
+E5500_CPU := -mcpu=powerpc64
+endif
  CFLAGS-$(CONFIG_E5500_CPU) += $(E5500_CPU)
  CFLAGS-$(CONFIG_E6500_CPU) += $(call cc-option,-mcpu=e6500,$(E5500_CPU))

Tiejun

matter, if we're using -mcpu=whatever-ibm-chip-has-this?

Plus, wouldn't you need to do something to prevent code in that file
from being called?

-Scott

On Thu, 2013-11-21 at 16:59 +0800, "=E2=80=9Ctiejun.chen=E2=80=9D" wrote:

On 11/21/2013 12:41 AM, Scott Wood wrote:

quoted

On Wed, 2013-11-20 at 16:35 +0800, Tiejun Chen wrote:

quoted

+# Altivec and Spe options not allowed with e500mc64 in GCC.
+ifeq ($(call cc-option-yn,-mcpu=3De500mc64),n)
  obj-$(CONFIG_ALTIVEC)	+=3D xor_vmx.o
  CFLAGS_xor_vmx.o +=3D -maltivec -mabi=3Daltivec
+endif

This does not seem like the right fix.  What if GCC supports both
-mcpu=3De500mc64 and -mcpu=3De6500, and we're using the latter?  Or f=

or that

=20
I can understand what you mean, but in current kernel, -mcpu=3De500mc64=

 should be=20

excluded from -mcpu=3De6500,
=20
arch/powerpc/Makefile:
=20
E5500_CPU :=3D $(call cc-option,-mcpu=3De500mc64,-mcpu=3Dpowerpc64)
CFLAGS-$(CONFIG_E5500_CPU) +=3D $(E5500_CPU)
CFLAGS-$(CONFIG_E6500_CPU) +=3D $(call cc-option,-mcpu=3De6500,$(E5500_=

CPU))

But your patch doesn't test what options we're actually using.  You
tested what options the compiler supports.

But unfortunately, another place also use the same option,
=20
lib/raid6/Makefile:
=20
raid6_pq-$(CONFIG_ALTIVEC) +=3D altivec1.o altivec2.o altivec4.o altive=

c8.o

...
ifeq ($(CONFIG_ALTIVEC),y)
altivec_flags :=3D -maltivec -mabi=3Daltivec
endif
=20
Looks we have to do something in this common Makefile file as well, but=

 it may=20

-mcpu=3Dpower5)

  CFLAGS-$(CONFIG_POWER6_CPU) +=3D $(call cc-option,-mcpu=3Dpower6)
  CFLAGS-$(CONFIG_POWER7_CPU) +=3D $(call cc-option,-mcpu=3Dpower7)
=20
+# Altivec and Spe options not allowed with e500mc64 in GCC.
+ifeq ($(CONFIG_ALTIVEC),)
  E5500_CPU :=3D $(call cc-option,-mcpu=3De500mc64,-mcpu=3Dpowerpc64)
+else
+E5500_CPU :=3D -mcpu=3Dpowerpc64
+endif
  CFLAGS-$(CONFIG_E5500_CPU) +=3D $(E5500_CPU)
  CFLAGS-$(CONFIG_E6500_CPU) +=3D $(call cc-option,-mcpu=3De6500,$(E550=

0_CPU))

Reverse the if/else so it uses positive logic, and remove the irrelevant
SPE from the comment, but otherwise I guess it's OK.

-Scott