| Message ID | 20230203135043.409192-3-james.morse@arm.com (mailing list archive) |
|---|---|
| State | RFC, archived |
| Headers | show |
| Series | ACPI/arm64: add support for virtual cpuhotplug | expand |
On Fri, Feb 03, 2023 at 01:50:13PM +0000, James Morse wrote: > --- a/arch/ia64/Kconfig > +++ b/arch/ia64/Kconfig > @@ -15,6 +15,7 @@ config IA64 > select ARCH_MIGHT_HAVE_PC_PARPORT > select ARCH_MIGHT_HAVE_PC_SERIO > select ACPI > + select ACPI_HOTPLUG_CPU if ACPI > --- a/arch/loongarch/Kconfig > +++ b/arch/loongarch/Kconfig > @@ -5,6 +5,7 @@ config LOONGARCH > select ACPI > select ACPI_GENERIC_GSI if ACPI > select ACPI_MCFG if ACPI > + select ACPI_HOTPLUG_CPU if ACPI > --- a/arch/x86/Kconfig > +++ b/arch/x86/Kconfig > @@ -59,6 +59,7 @@ config X86 > # > select ACPI_LEGACY_TABLES_LOOKUP if ACPI > select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI > + select ACPI_HOTPLUG_CPU if ACPI > --- a/drivers/acpi/Kconfig > +++ b/drivers/acpi/Kconfig > @@ -309,7 +309,6 @@ config ACPI_HOTPLUG_CPU > bool > depends on ACPI_PROCESSOR && HOTPLUG_CPU > select ACPI_CONTAINER > - default y When selecting the symbol, it's a good idea to ensure that its dependencies are satisfied. So here, ACPI_HOTPLUG_CPU depends on ACPI_PROCESSOR and HOTPLUG_CPU. For x86, you're selecting ACPI_HOTPLUG_CPU if ACPI is enabled, and ACPI can be freely enabled. HOTPLUG_CPU depends on SMP, which is also a freely selectable option. Lastly, ACPI_PROCESSOR depends on X86 || IA64 || ARM64 || LOONGARCH, and is a user selectable, defaulting-y option if ACPI is enabled. So, shouldn't the x86 select be: select ACPI_HOTPLUG_CPU if ACPI_PROCESSOR && HOTPLUG_CPU ? I suspect similar issues exist for the other architecture Kconfig files modified above. This seems to also be in the latest rfc too, which is why I'm bringing it up. Thanks.
diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig index d7e4a24e8644..deabb8843aea 100644 --- a/arch/ia64/Kconfig +++ b/arch/ia64/Kconfig @@ -15,6 +15,7 @@ config IA64 select ARCH_MIGHT_HAVE_PC_PARPORT select ARCH_MIGHT_HAVE_PC_SERIO select ACPI + select ACPI_HOTPLUG_CPU if ACPI select ACPI_NUMA if NUMA select ARCH_ENABLE_MEMORY_HOTPLUG select ARCH_ENABLE_MEMORY_HOTREMOVE diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig index 9cc8b84f7eb0..075aa50e5d5f 100644 --- a/arch/loongarch/Kconfig +++ b/arch/loongarch/Kconfig @@ -5,6 +5,7 @@ config LOONGARCH select ACPI select ACPI_GENERIC_GSI if ACPI select ACPI_MCFG if ACPI + select ACPI_HOTPLUG_CPU if ACPI select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI select ARCH_BINFMT_ELF_STATE select ARCH_ENABLE_MEMORY_HOTPLUG diff --git a/arch/loongarch/include/asm/cpu.h b/arch/loongarch/include/asm/cpu.h index 754f28506791..da79862ff1f3 100644 --- a/arch/loongarch/include/asm/cpu.h +++ b/arch/loongarch/include/asm/cpu.h @@ -124,4 +124,11 @@ enum cpu_type_enum { #define LOONGARCH_CPU_GUESTID BIT_ULL(CPU_FEATURE_GUESTID) #define LOONGARCH_CPU_HYPERVISOR BIT_ULL(CPU_FEATURE_HYPERVISOR) +#if !defined(__ASSEMBLY__) +#ifdef CONFIG_HOTPLUG_CPU +extern int arch_register_cpu(int num); +extern void arch_unregister_cpu(int); +#endif +#endif /* ! __ASSEMBLY__ */ + #endif /* _ASM_CPU_H */ diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 3604074a878b..6a520c22c3eb 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -59,6 +59,7 @@ config X86 # select ACPI_LEGACY_TABLES_LOOKUP if ACPI select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI + select ACPI_HOTPLUG_CPU if ACPI select ARCH_32BIT_OFF_T if X86_32 select ARCH_CLOCKSOURCE_INIT select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig index ccbeab9500ec..4845e5b525ac 100644 --- a/drivers/acpi/Kconfig +++ b/drivers/acpi/Kconfig @@ -309,7 +309,6 @@ config ACPI_HOTPLUG_CPU bool depends on ACPI_PROCESSOR && HOTPLUG_CPU select ACPI_CONTAINER - default y config ACPI_PROCESSOR_AGGREGATOR tristate "Processor Aggregator" diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c index 6737b1cbf6d6..16b314340e68 100644 --- a/drivers/acpi/acpi_processor.c +++ b/drivers/acpi/acpi_processor.c @@ -150,24 +150,6 @@ static int acpi_processor_errata(void) /* Initialization */ #ifdef CONFIG_ACPI_HOTPLUG_CPU -int __weak acpi_map_cpu(acpi_handle handle, - phys_cpuid_t physid, u32 acpi_id, int *pcpu) -{ - return -ENODEV; -} - -int __weak acpi_unmap_cpu(int cpu) -{ - return -ENODEV; -} - -int __weak arch_register_cpu(int cpu) -{ - return -ENODEV; -} - -void __weak arch_unregister_cpu(int cpu) {} - static int acpi_processor_hotadd_init(struct acpi_processor *pr) { unsigned long long sta;
arm64 doesn't support physical hotadd of CPUs that were not present at boot. Much of the platform description is in static tables which do not have update methods. arm64 does support HOTPLUG_CPU, which is backed by a firmware interface to turn CPUs on and off. acpi_processor_hotadd_init() and acpi_processor_remove() are for adding and removing CPUs that were not present at boot. arm64 systems that do this are not supported as there is currently insufficient information in the platform description. (e.g. did the GICR get removed too?) arm64 currently relies on the MADT enabled flag check in map_gicc_mpidr() to prevent CPUs that were not described as present at boot from being added to the system. Adding support for virtual CPU hotplug (where the vCPUs have been present the whole time) would require this check to be removed, possibly allowing physical CPUs to be added. Disable ACPI_HOTPLUG_CPU for arm64 by removing 'default y' and selecting it on the other three ACPI architectures. This allows the weak definitions of some symbols to be removed. Signed-off-by: James Morse <james.morse@arm.com> --- arch/ia64/Kconfig | 1 + arch/loongarch/Kconfig | 1 + arch/loongarch/include/asm/cpu.h | 7 +++++++ arch/x86/Kconfig | 1 + drivers/acpi/Kconfig | 1 - drivers/acpi/acpi_processor.c | 18 ------------------ 6 files changed, 10 insertions(+), 19 deletions(-)