On 11/22/23 2:53 PM, Vishal Chourasia wrote: > Changed HOTPLUG_CPU dependency to SMP and either ARCH_HIBERNATION_POSSIBLE or > ARCH_SUSPEND_POSSIBLE, aligning with systems' suspend/hibernation > capabilities. > This update links CPU hotplugging more logically with platforms' capabilities. > > Other changes include > > 1. configs ARCH_HIBERNATION_POSSIBLE and ARCH_SUSPEND_POSSIBLE are now > selected > only if required platform dependencies are met. > > 2. Defaults for configs ARCH_HIBERNATION_POSSIBLE and > ARCH_SUSPEND_POSSIBLE has been set to 'N' > > Reported-by: Srikar Dronamraju <sri...@linux.vnet.ibm.com> > Suggested-by: Aneesh Kumar K V <aneesh.ku...@linux.ibm.com> > Suggested-by: Michael Ellerman <m...@ellerman.id.au> > Signed-off-by: Vishal Chourasia <vish...@linux.ibm.com> > > v1: https://lore.kernel.org/all/20231114082046.6018-1-vish...@linux.ibm.com > --- > During the configuration process with 'make randconfig' followed by > 'make olddefconfig', we observed a warning indicating an unmet direct > dependency for the HOTPLUG_CPU option. The dependency in question relates to > various PowerPC configurations (PPC_PSERIES, PPC_PMAC, PPC_POWERNV, > FSL_SOC_BOOKE) which were not enabled, yet the HOTPLUG_CPU was being > erroneously selected due to an implicit assumption by the PM_SLEEP_SMP option. > This misalignment in dependencies could potentially lead to inconsistent > kernel > configuration states, especially when considering the necessary hardware > support for CPU hot-plugging on PowerPC platforms. The patch aims to correct > this by ensuring that ARCH_HIBERNATION_POSSIBLE is contingent upon the > appropriate PowerPC configurations being active. > > steps to reproduce (before applying the patch): > > Run 'make pseries_le_defconfig' > Run 'make menuconfig' > Enable hibernation [ Kernel options -> Hibernation (aka 'suspend to disk') ] > Disable [ Platform support -> IBM PowerNV (Non-Virtualized) platform support ] > Disable [ Platform support -> IBM pSeries & new (POWER5-based) iSeries ] > Enable SMP [ Processor support -> Symmetric multi-processing support ] > Save the config > Run 'make olddefconfig' > > arch/powerpc/Kconfig | 13 +++++-------- > 1 file changed, 5 insertions(+), 8 deletions(-) > > diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig > index 6f105ee4f3cf..6e7e9af2f0c1 100644 > --- a/arch/powerpc/Kconfig > +++ b/arch/powerpc/Kconfig > @@ -155,6 +155,8 @@ config PPC > select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST > select ARCH_HAS_UACCESS_FLUSHCACHE > select ARCH_HAS_UBSAN_SANITIZE_ALL > + select ARCH_HIBERNATION_POSSIBLE if (PPC_PSERIES || PPC_PMAC || > PPC_POWERNV || FSL_SOC_BOOKE) > + select ARCH_SUSPEND_POSSIBLE if (ADB_PMU || PPC_EFIKA || > PPC_LITE5200 || PPC_83xx || (PPC_85xx && !PPC_E500MC) || PPC_86xx || > PPC_PSERIES || 44x || 40x)
We should keep that sorted as explained in comment around that. > select ARCH_HAVE_NMI_SAFE_CMPXCHG > select ARCH_KEEP_MEMBLOCK > select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE if PPC_RADIX_MMU > @@ -380,14 +382,10 @@ config DEFAULT_UIMAGE > Used to allow a board to specify it wants a uImage built by default > > config ARCH_HIBERNATION_POSSIBLE > - bool > - default y > + def_bool n We should be able to keep this config ARCH_HIBERNATION_POSSIBLE bool That is how we have rest of the ARCH_* config. I am not sure we need to explicitly say "def_bool n" > > config ARCH_SUSPEND_POSSIBLE > - def_bool y > - depends on ADB_PMU || PPC_EFIKA || PPC_LITE5200 || PPC_83xx || \ > - (PPC_85xx && !PPC_E500MC) || PPC_86xx || PPC_PSERIES \ > - || 44x || 40x > + def_bool n > > config ARCH_SUSPEND_NONZERO_CPU > def_bool y > @@ -568,8 +566,7 @@ config ARCH_USING_PATCHABLE_FUNCTION_ENTRY > > config HOTPLUG_CPU > bool "Support for enabling/disabling CPUs" > - depends on SMP && (PPC_PSERIES || \ > - PPC_PMAC || PPC_POWERNV || FSL_SOC_BOOKE) > + depends on SMP && (ARCH_HIBERNATION_POSSIBLE || ARCH_SUSPEND_POSSIBLE) > help > Say Y here to be able to disable and re-enable individual > CPUs at runtime on SMP machines.