Hi Salil,
On 29/9/23 17:47, Salil Mehta wrote:
From: Alex Bennée <[email protected]>
Sent: Friday, September 29, 2023 3:27 PM
To: Salil Mehta <[email protected]>
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Subject: Re: [PATCH 3/9] hw/acpi: Add ACPI CPU hotplug init stub
Salil Mehta <[email protected]> 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 <[email protected]>
---
hw/acpi/acpi-cpu-hotplug-stub.c | 6 ++++++
1 file changed, 6 insertions(+)
