Commit 9d087389 authored by Jonathan Cameron's avatar Jonathan Cameron Committed by Catalin Marinas
Browse files

arm64: Kconfig: Enable hotplug CPU on arm64 if ACPI_PROCESSOR is enabled. 



In order to move arch_register_cpu() to be called via the same path
for initially present CPUs described by ACPI and hotplugged CPUs
ACPI_HOTPLUG_CPU needs to be enabled.

The protection against invalid IDs in acpi_map_cpu() is needed as
at least one production BIOS is in the wild which reports entries
in DSDT (with no _STA method, so assumed enabled and present)
that don't match MADT.

Tested-by: default avatarMiguel Luis <miguel.luis@oracle.com>
Reviewed-by: default avatarGavin Shan <gshan@redhat.com>
Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20240529133446.28446-18-Jonathan.Cameron@huawei.com


Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent eba46750

arch/arm64/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -5,6 +5,7 @@ config ARM64 
	select ACPI_CCA_REQUIRED if ACPI

	select ACPI_GENERIC_GSI if ACPI

	select ACPI_GTDT if ACPI

	select ACPI_HOTPLUG_CPU if ACPI_PROCESSOR

	select ACPI_IORT if ACPI

	select ACPI_REDUCED_HARDWARE_ONLY if ACPI

	select ACPI_MCFG if (ACPI && PCI)

arch/arm64/kernel/acpi.c

+22 −0
Original line number Diff line number Diff line
@@ -30,6 +30,7 @@ 
#include <linux/pgtable.h>



#include <acpi/ghes.h>

#include <acpi/processor.h>

#include <asm/cputype.h>

#include <asm/cpu_ops.h>

#include <asm/daifflags.h>
@@ -423,6 +424,27 @@ void arch_reserve_mem_area(acpi_physical_address addr, size_t size) 
	memblock_mark_nomap(addr, size);

}



#ifdef CONFIG_ACPI_HOTPLUG_CPU

int acpi_map_cpu(acpi_handle handle, phys_cpuid_t physid, u32 apci_id,

		 int *pcpu)

{

	/* If an error code is passed in this stub can't fix it */

	if (*pcpu < 0) {

		pr_warn_once("Unable to map CPU to valid ID\n");

		return *pcpu;

	}



	return 0;

}

EXPORT_SYMBOL(acpi_map_cpu);



int acpi_unmap_cpu(int cpu)

{

	return 0;

}

EXPORT_SYMBOL(acpi_unmap_cpu);

#endif /* CONFIG_ACPI_HOTPLUG_CPU */



#ifdef CONFIG_ACPI_FFH

/*

 * Implements ARM64 specific callbacks to support ACPI FFH Operation Region as