3.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: "Srivatsa S. Bhat" <srivatsa.bhat@xxxxxxxxxxxxxxxxxx> commit f274ef8747d3be649bba8708696fb31cb00fa75a upstream. 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@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@xxxxxxxxxxxxxxxxxx> Signed-off-by: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/powerpc/platforms/pseries/Kconfig | 2 ++ 1 file changed, 2 insertions(+) --- a/arch/powerpc/platforms/pseries/Kconfig +++ b/arch/powerpc/platforms/pseries/Kconfig @@ -18,6 +18,8 @@ config PPC_PSERIES select PPC_PCI_CHOICE if EXPERT select ZLIB_DEFLATE select PPC_DOORBELL + select HOTPLUG if SMP + select HOTPLUG_CPU if SMP default y config PPC_SPLPAR -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html