From a02f66bb3cf475947b58dd3851b987b8ccd998c1 Mon Sep 17 00:00:00 2001 From: James Morse Date: Tue, 21 Nov 2023 13:44:15 +0000 Subject: ACPI: Move ACPI_HOTPLUG_CPU to be disabled on arm64 and riscv 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 Reviewed-by: Shaoqin Huang Reviewed-by: Gavin Shan Signed-off-by: "Russell King (Oracle)" Reviewed-by: Jonathan Cameron Reviewed-by: Thomas Gleixner Link: https://lore.kernel.org/r/E1r5R31-00Csyt-Jq@rmk-PC.armlinux.org.uk Signed-off-by: Greg Kroah-Hartman --- arch/x86/Kconfig | 1 + 1 file changed, 1 insertion(+) (limited to 'arch/x86/Kconfig') 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 -- cgit v1.2.3