[PATCH 1/2] powerpc/32: Add ppc_defconfig

Add a generic 32-bit defconfig called ppc_defconfig. This means we'll
have a defconfig matching "uname -m" for all cases.

This config is mostly intended for build testing but if someone wants
to tweak it to get it booting on something that would be fine too.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---
 arch/powerpc/Makefile | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
index ac033341ed55..70e6e8119aeb 100644
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile

@@ -367,6 +367,10 @@ PHONY += ppc32_allmodconfig
 	$(Q)$(MAKE) KCONFIG_ALLCONFIG=$(srctree)/arch/powerpc/configs/book3s_32.config \
 		-f $(srctree)/Makefile allmodconfig
 
+PHONY += ppc_defconfig
+ppc_defconfig:
+	$(call merge_into_defconfig,book3s_32.config,)
+
 PHONY += ppc64le_allmodconfig
 ppc64le_allmodconfig:
 	$(Q)$(MAKE) KCONFIG_ALLCONFIG=$(srctree)/arch/powerpc/configs/le.config \

-- 
2.20.1

Our logic for choosing defconfig doesn't work well in some situations.

For example if you're on a ppc64le machine but you specify a non-empty
CROSS_COMPILE, in order to use a non-default toolchain, then defconfig
will give you ppc64_defconfig (big endian):

  $ make CROSS_COMPILE=~/toolchains/gcc-8/bin/powerpc-linux- defconfig
  *** Default configuration is based on 'ppc64_defconfig'

This is because we assume that CROSS_COMPILE being set means we
can't be on a ppc machine and rather than checking we just default to
ppc64_defconfig.

We should just ignore CROSS_COMPILE, instead check the machine with
uname and if it's one of ppc, ppc64 or ppc64le then use that
defconfig. If it's none of those then we fall back to ppc64_defconfig.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---
 arch/powerpc/Makefile | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
index 70e6e8119aeb..81563986a30e 100644
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile

@@ -34,11 +34,10 @@ ifdef CONFIG_PPC_BOOK3S_32
 KBUILD_CFLAGS		+= -mcpu=powerpc
 endif
 
-ifeq ($(CROSS_COMPILE),)
-KBUILD_DEFCONFIG := $(shell uname -m)_defconfig
-else
-KBUILD_DEFCONFIG := ppc64_defconfig
-endif
+# If we're on a ppc/ppc64/ppc64le machine use that defconfig, otherwise just use
+# ppc64_defconfig because we have nothing better to go on.
+uname := $(shell uname -m)
+KBUILD_DEFCONFIG := $(if $(filter ppc%,$(uname)),$(uname),ppc64)_defconfig
 
 ifdef CONFIG_PPC64
 new_nm := $(shell if $(NM) --help 2>&1 | grep -- '--synthetic' > /dev/null; then echo y; else echo n; fi)

-- 
2.20.1

On Thu, Feb 7, 2019 at 6:18 AM Michael Ellerman [off-list ref] wrote:

Add a generic 32-bit defconfig called ppc_defconfig. This means we'll
have a defconfig matching "uname -m" for all cases.

Looks good to me:

$ make defconfig
*** Default configuration is based on 'ppc_defconfig'
arch/powerpc/configs/ppc_defconfig:175:warning: symbol value 'm'
invalid for NF_TABLES_INET
arch/powerpc/configs/ppc_defconfig:176:warning: symbol value 'm'
invalid for NF_TABLES_NETDEV
arch/powerpc/configs/ppc_defconfig:304:warning: symbol value 'm'
invalid for NF_TABLES_ARP
arch/powerpc/configs/ppc_defconfig:358:warning: symbol value 'm'
invalid for NF_TABLES_BRIDGE
arch/powerpc/configs/ppc_defconfig:1427:warning: symbol value 'm'
invalid for LIRC
#
# configuration written to .config
#

Tested-by: Mathieu Malaterre <redacted>

On Thu, Feb 7, 2019 at 6:20 AM Michael Ellerman [off-list ref] wrote:

Our logic for choosing defconfig doesn't work well in some situations.

For example if you're on a ppc64le machine but you specify a non-empty
CROSS_COMPILE, in order to use a non-default toolchain, then defconfig
will give you ppc64_defconfig (big endian):

  $ make CROSS_COMPILE=~/toolchains/gcc-8/bin/powerpc-linux- defconfig
  *** Default configuration is based on 'ppc64_defconfig'

This is because we assume that CROSS_COMPILE being set means we
can't be on a ppc machine and rather than checking we just default to
ppc64_defconfig.

We should just ignore CROSS_COMPILE, instead check the machine with
uname and if it's one of ppc, ppc64 or ppc64le then use that
defconfig. If it's none of those then we fall back to ppc64_defconfig.

How about shamelessly copying x86:

diff --git a/Makefile b/Makefile
index 3142e67d03f1..041616742142 100644
--- a/Makefile
+++ b/Makefile

@@ -351,6 +351,14 @@ ifeq ($(ARCH),sparc64)
        SRCARCH := sparc
 endif

+# Additional ARCH settings for ppc
+ifeq ($(ARCH),ppc64)
+       SRCARCH := powerpc
+endif
+ifeq ($(ARCH),ppc64el)
+       SRCARCH := powerpc
+endif
+
 # Additional ARCH settings for sh
 ifeq ($(ARCH),sh64)
        SRCARCH := sh

diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
index 10bf5dc7cdf0..cbb679fb7162 100644
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile

@@ -34,10 +34,17 @@ ifdef CONFIG_PPC_BOOK3S_32
 KBUILD_CFLAGS          += -mcpu=powerpc
 endif

-# If we're on a ppc/ppc64/ppc64le machine use that defconfig,

otherwise just use
-# ppc64_defconfig because we have nothing better to go on.
-uname := $(shell uname -m)
-KBUILD_DEFCONFIG := $(if $(filter ppc%,$(uname)),$(uname),ppc64)_defconfig
+# select defconfig based on actual architecture
+ifeq ($(ARCH),powerpc)
+  ifeq ($(shell uname -m),ppc64)
+        KBUILD_DEFCONFIG := ppc64_defconfig
+  else
+        KBUILD_DEFCONFIG := ppc_defconfig
+  endif
+else
+        KBUILD_DEFCONFIG := $(ARCH)_defconfig
+endif
+

 ifdef CONFIG_PPC64
 new_nm := $(shell if $(NM) --help 2>&1 | grep -- '--synthetic' >
/dev/null; then echo y; else echo n; fi)

On Thu, 2019-02-07 at 05:16:51 UTC, Michael Ellerman wrote:

Add a generic 32-bit defconfig called ppc_defconfig. This means we'll
have a defconfig matching "uname -m" for all cases.

This config is mostly intended for build testing but if someone wants
to tweak it to get it booting on something that would be fine too.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Tested-by: Mathieu Malaterre <redacted>

Series applied to powerpc next.

https://git.kernel.org/powerpc/c/a273fa386a947612a23b0d56dcfb8823

cheers