| Message ID | E1r5R31-00Csyt-Jq@rmk-PC.armlinux.org.uk |
|---|---|
| State | New |
| Headers | show |
| Series | Initial cleanups for vCPU hotplug | expand |
On Tue, Nov 21, 2023 at 2:44 PM Russell King <rmk+kernel@armlinux.org.uk> wrote: > > From: James Morse <james.morse@arm.com> > > Neither arm64 nor riscv support physical hotadd of CPUs that were not > present at boot. For arm64 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. Similarly, riscv relies on the same check in > map_rintc_hartid(). Both architectures also rely on the weak 'always fails' > definitions of acpi_map_cpu() and arch_register_cpu(). > > Subsequent changes will redefine ACPI_HOTPLUG_CPU as making possible > CPUs present. Neither arm64 nor riscv support this. > > Disable ACPI_HOTPLUG_CPU for arm64 and riscv 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> > Reviewed-by: Shaoqin Huang <shahuang@redhat.com> > Reviewed-by: Gavin Shan <gshan@redhat.com> > Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> I can apply this if it gets ACKs from the maintainers of the affected architectures. > --- > Changes since RFC: > * Expanded conditions to avoid ACPI_HOTPLUG_CPU being enabled when > HOTPLUG_CPU isn't. > Changes since RFC v3: > * Dropped ia64 changes > --- > arch/loongarch/Kconfig | 1 + > arch/x86/Kconfig | 1 + > drivers/acpi/Kconfig | 1 - > drivers/acpi/acpi_processor.c | 18 ------------------ > 4 files changed, 2 insertions(+), 19 deletions(-) > > diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig > index ee123820a476..331becb2cb4f 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_PROCESSOR && HOTPLUG_CPU > select ACPI_PPTT if ACPI > select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI > select ARCH_BINFMT_ELF_STATE > diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig > index 3762f41bb092..dbdcfc708369 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_PROCESSOR && HOTPLUG_CPU > 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 f819e760ff19..a3acfc750fce 100644 > --- a/drivers/acpi/Kconfig > +++ b/drivers/acpi/Kconfig > @@ -310,7 +310,6 @@ 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 0f5218e361df..4fe2ef54088c 100644 > --- a/drivers/acpi/acpi_processor.c > +++ b/drivers/acpi/acpi_processor.c > @@ -184,24 +184,6 @@ static void __init acpi_pcc_cpufreq_init(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; > -- > 2.30.2 >
On Tue, 21 Nov 2023 13:44:15 +0000 Russell King <rmk+kernel@armlinux.org.uk> wrote: > From: James Morse <james.morse@arm.com> > > Neither arm64 nor riscv support physical hotadd of CPUs that were not > present at boot. For arm64 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. Similarly, riscv relies on the same check in > map_rintc_hartid(). Both architectures also rely on the weak 'always fails' > definitions of acpi_map_cpu() and arch_register_cpu(). > > Subsequent changes will redefine ACPI_HOTPLUG_CPU as making possible > CPUs present. Neither arm64 nor riscv support this. > > Disable ACPI_HOTPLUG_CPU for arm64 and riscv 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> > Reviewed-by: Shaoqin Huang <shahuang@redhat.com> > Reviewed-by: Gavin Shan <gshan@redhat.com> > Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig index ee123820a476..331becb2cb4f 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_PROCESSOR && HOTPLUG_CPU select ACPI_PPTT if ACPI select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI select ARCH_BINFMT_ELF_STATE diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 3762f41bb092..dbdcfc708369 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_PROCESSOR && HOTPLUG_CPU 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 f819e760ff19..a3acfc750fce 100644 --- a/drivers/acpi/Kconfig +++ b/drivers/acpi/Kconfig @@ -310,7 +310,6 @@ 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 0f5218e361df..4fe2ef54088c 100644 --- a/drivers/acpi/acpi_processor.c +++ b/drivers/acpi/acpi_processor.c @@ -184,24 +184,6 @@ static void __init acpi_pcc_cpufreq_init(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;