| Message ID | 20230929124304.13672-4-salil.mehta@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Add architecture agnostic code to support vCPU Hotplug | expand |
Salil Mehta <salil.mehta@huawei.com> writes: > ACPI CPU hotplug related initialization should only happen if ACPI_CPU_HOTPLUG > support has been enabled for particular architecture. Add cpu_hotplug_hw_init() > stub to avoid compilation break. When does the compilation break? It's usually ok to include stubs with that commit. > > Signed-off-by: Salil Mehta <salil.mehta@huawei.com> > --- > hw/acpi/acpi-cpu-hotplug-stub.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/hw/acpi/acpi-cpu-hotplug-stub.c b/hw/acpi/acpi-cpu-hotplug-stub.c > index 3fc4b14c26..c6c61bb9cd 100644 > --- a/hw/acpi/acpi-cpu-hotplug-stub.c > +++ b/hw/acpi/acpi-cpu-hotplug-stub.c > @@ -19,6 +19,12 @@ void legacy_acpi_cpu_hotplug_init(MemoryRegion *parent, Object *owner, > return; > } > > +void cpu_hotplug_hw_init(MemoryRegion *as, Object *owner, > + CPUHotplugState *state, hwaddr base_addr) > +{ > + return; > +} > + > void acpi_cpu_ospm_status(CPUHotplugState *cpu_st, ACPIOSTInfoList ***list) > { > return;
> From: Alex Bennée <alex.bennee@linaro.org> > Sent: Friday, September 29, 2023 3:27 PM > To: Salil Mehta <salil.mehta@huawei.com> > Cc: qemu-devel@nongnu.org; qemu-arm@nongnu.org; maz@kernel.org; jean- > philippe@linaro.org; Jonathan Cameron <jonathan.cameron@huawei.com>; > lpieralisi@kernel.org; peter.maydell@linaro.org; > richard.henderson@linaro.org; imammedo@redhat.com; andrew.jones@linux.dev; > david@redhat.com; philmd@linaro.org; eric.auger@redhat.com; > oliver.upton@linux.dev; pbonzini@redhat.com; mst@redhat.com; > will@kernel.org; gshan@redhat.com; rafael@kernel.org; > linux@armlinux.org.uk; darren@os.amperecomputing.com; > ilkka@os.amperecomputing.com; vishnu@os.amperecomputing.com; > karl.heubaum@oracle.com; miguel.luis@oracle.com; salil.mehta@opnsrc.net; > zhukeqian <zhukeqian1@huawei.com>; wangxiongfeng (C) > <wangxiongfeng2@huawei.com>; wangyanan (Y) <wangyanan55@huawei.com>; > jiakernel2@gmail.com; maobibo@loongson.cn; lixianglai@loongson.cn; Linuxarm > <linuxarm@huawei.com> > Subject: Re: [PATCH 3/9] hw/acpi: Add ACPI CPU hotplug init stub > > > Salil Mehta <salil.mehta@huawei.com> writes: > > > ACPI CPU hotplug related initialization should only happen if ACPI_CPU_HOTPLUG > > support has been enabled for particular architecture. Add cpu_hotplug_hw_init() > > stub to avoid compilation break. > > When does the compilation break? It's usually ok to include stubs with > that commit. To be specific. it is not a compilation break but linking error. Support of ACPI_CPU_HOTPLUG is optional. This flag is defined in architecture specific Kconfig. Function cpu_hotplug_hw_init() is part of the hw/acpi/cpu.c which gets compiled only when a particular architecture defines ACPI_CPU_HOTPLUG flag. ACPI GED framework support for CPU Hotplug is not specific to any architecture. acpi_ged_initfn() calls cpu_hotplug_hw_init() when GED device gets created. This functions gets called irrespective of the fact CPU Hotplug is supported or not. If ACPI_CPU_HOTPLUG is not enabled then presence of cpu_hotplug_hw_init() will cause linking error without the presence of stub. Thanks Salil. > > Signed-off-by: Salil Mehta <salil.mehta@huawei.com> > > --- > > hw/acpi/acpi-cpu-hotplug-stub.c | 6 ++++++ > > 1 file changed, 6 insertions(+) > > > > diff --git a/hw/acpi/acpi-cpu-hotplug-stub.c b/hw/acpi/acpi-cpu-hotplug- > stub.c > > index 3fc4b14c26..c6c61bb9cd 100644 > > --- a/hw/acpi/acpi-cpu-hotplug-stub.c > > +++ b/hw/acpi/acpi-cpu-hotplug-stub.c > > @@ -19,6 +19,12 @@ void legacy_acpi_cpu_hotplug_init(MemoryRegion > *parent, Object *owner, > > return; > > } > > > > +void cpu_hotplug_hw_init(MemoryRegion *as, Object *owner, > > + CPUHotplugState *state, hwaddr base_addr) > > +{ > > + return; > > +} > > + > > void acpi_cpu_ospm_status(CPUHotplugState *cpu_st, ACPIOSTInfoList > ***list) > > { > > return; > > > -- > Alex Bennée > Virtualisation Tech Lead @ Linaro
Hi Salil, On 29/9/23 17:47, Salil Mehta wrote: >> From: Alex Bennée <alex.bennee@linaro.org> >> Sent: Friday, September 29, 2023 3:27 PM >> To: Salil Mehta <salil.mehta@huawei.com> >> Cc: qemu-devel@nongnu.org; qemu-arm@nongnu.org; maz@kernel.org; jean- >> philippe@linaro.org; Jonathan Cameron <jonathan.cameron@huawei.com>; >> lpieralisi@kernel.org; peter.maydell@linaro.org; >> richard.henderson@linaro.org; imammedo@redhat.com; andrew.jones@linux.dev; >> david@redhat.com; philmd@linaro.org; eric.auger@redhat.com; >> oliver.upton@linux.dev; pbonzini@redhat.com; mst@redhat.com; >> will@kernel.org; gshan@redhat.com; rafael@kernel.org; >> linux@armlinux.org.uk; darren@os.amperecomputing.com; >> ilkka@os.amperecomputing.com; vishnu@os.amperecomputing.com; >> karl.heubaum@oracle.com; miguel.luis@oracle.com; salil.mehta@opnsrc.net; >> zhukeqian <zhukeqian1@huawei.com>; wangxiongfeng (C) >> <wangxiongfeng2@huawei.com>; wangyanan (Y) <wangyanan55@huawei.com>; >> jiakernel2@gmail.com; maobibo@loongson.cn; lixianglai@loongson.cn; Linuxarm >> <linuxarm@huawei.com> >> Subject: Re: [PATCH 3/9] hw/acpi: Add ACPI CPU hotplug init stub >> >> >> Salil Mehta <salil.mehta@huawei.com> writes: >> >>> ACPI CPU hotplug related initialization should only happen if ACPI_CPU_HOTPLUG >>> support has been enabled for particular architecture. Add cpu_hotplug_hw_init() >>> stub to avoid compilation break. >> >> When does the compilation break? It's usually ok to include stubs with >> that commit. > > > To be specific. it is not a compilation break but linking error. > > Support of ACPI_CPU_HOTPLUG is optional. This flag is defined in architecture > specific Kconfig. Function cpu_hotplug_hw_init() is part of the hw/acpi/cpu.c > which gets compiled only when a particular architecture defines ACPI_CPU_HOTPLUG > flag. > > ACPI GED framework support for CPU Hotplug is not specific to any architecture. > acpi_ged_initfn() calls cpu_hotplug_hw_init() when GED device gets created. > This functions gets called irrespective of the fact CPU Hotplug is supported or > not. If ACPI_CPU_HOTPLUG is not enabled then presence of cpu_hotplug_hw_init() > will cause linking error without the presence of stub. We can extract the common pattern in both - ich9_pm_set_cpu_hotplug_legacy() - piix4_set_cpu_hotplug_legacy() to take (AcpiCpuHotplug, CPUHotplugState) params, then guard the cpu_hotplug_hw_init() call within CONFIG_ACPI_CPU_HOTPLUG ifdef'ry. Doing so we can also remove the acpi_switch_to_modern_cphp() stub. Regards, Phil. >>> Signed-off-by: Salil Mehta <salil.mehta@huawei.com> >>> --- >>> hw/acpi/acpi-cpu-hotplug-stub.c | 6 ++++++ >>> 1 file changed, 6 insertions(+)
diff --git a/hw/acpi/acpi-cpu-hotplug-stub.c b/hw/acpi/acpi-cpu-hotplug-stub.c index 3fc4b14c26..c6c61bb9cd 100644 --- a/hw/acpi/acpi-cpu-hotplug-stub.c +++ b/hw/acpi/acpi-cpu-hotplug-stub.c @@ -19,6 +19,12 @@ void legacy_acpi_cpu_hotplug_init(MemoryRegion *parent, Object *owner, return; } +void cpu_hotplug_hw_init(MemoryRegion *as, Object *owner, + CPUHotplugState *state, hwaddr base_addr) +{ + return; +} + void acpi_cpu_ospm_status(CPUHotplugState *cpu_st, ACPIOSTInfoList ***list) { return;
ACPI CPU hotplug related initialization should only happen if ACPI_CPU_HOTPLUG support has been enabled for particular architecture. Add cpu_hotplug_hw_init() stub to avoid compilation break. Signed-off-by: Salil Mehta <salil.mehta@huawei.com> --- hw/acpi/acpi-cpu-hotplug-stub.c | 6 ++++++ 1 file changed, 6 insertions(+)