Revision f274ef8747d3be649bba8708696fb31cb00fa75a authored by Srivatsa S. Bhat on 21 May 2013, 09:32:48 UTC, committed by Benjamin Herrenschmidt on 31 May 2013, 22:29:27 UTC
Adam Lackorzynski reported the following build failure on
!CONFIG_HOTPLUG_CPU configuration:

  CC      arch/powerpc/kernel/rtas.o
arch/powerpc/kernel/rtas.c: In function ‘rtas_cpu_state_change_mask’:
arch/powerpc/kernel/rtas.c:843:4: error: implicit declaration of function ‘cpu_down’ [-Werror=implicit-function-declaration]
cc1: all warnings being treated as errors
make[1]: *** [arch/powerpc/kernel/rtas.o] Error 1
make: *** [arch/powerpc/kernel] Error 2

The build fails because cpu_down() is defined only under CONFIG_HOTPLUG_CPU.

Looking further, the mobility code in pseries is one of the call-sites which
uses rtas_ibm_suspend_me(), which in turn calls rtas_cpu_state_change_mask().
And the mobility code is unconditionally compiled-in (it does not fall under
any Kconfig option). And commit 120496ac (powerpc: Bring all threads online
prior to migration/hibernation) which introduced this build regression is
critical for the proper functioning of the migration code. So it appears
that the only solution to this problem is to enable CONFIG_HOTPLUG_CPU if
SMP is enabled on PPC_PSERIES platforms. So make that change in the Kconfig.

Reported-by: Adam Lackorzynski <adam@os.inf.tu-dresden.de>
Cc: stable@vger.kernel.org
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
1 parent 8e44ddc
Raw File
Makefile.asm-generic
# include/asm-generic contains a lot of files that are used
# verbatim by several architectures.
#
# This Makefile reads the file arch/$(SRCARCH)/include/asm/Kbuild
# and for each file listed in this file with generic-y creates
# a small wrapper file in $(obj) (arch/$(SRCARCH)/include/generated/asm)

kbuild-file := $(srctree)/arch/$(SRCARCH)/include/$(src)/Kbuild
-include $(kbuild-file)

include scripts/Kbuild.include

# Create output directory if not already present
_dummy := $(shell [ -d $(obj) ] || mkdir -p $(obj))

quiet_cmd_wrap = WRAP    $@
cmd_wrap = echo "\#include <asm-generic/$*.h>" >$@

all: $(patsubst %, $(obj)/%, $(generic-y))
	@:

$(obj)/%.h:
	$(call cmd,wrap)

back to top