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 From 5b95f94c3b9f12adf27e970d411e8a744e95cabf Mon Sep 17 00:00:00 2001 From: James Morse Date: Tue, 21 Nov 2023 13:45:01 +0000 Subject: x86/topology: Switch over to GENERIC_CPU_DEVICES Now that GENERIC_CPU_DEVICES calls arch_register_cpu(), which can be overridden by the arch code, switch over to this to allow common code to choose when the register_cpu() call is made. x86's struct cpus come from struct x86_cpu, which has no other members or users. Remove this and use the version defined by common code. This is an intermediate step to the logic being moved to drivers/acpi, where GENERIC_CPU_DEVICES will do the work when booting with acpi=off. This patch also has the effect of moving the registration of CPUs from subsys to driver core initialisation, prior to any initcalls running. ---- Changes since RFC: * Fixed the second copy of arch_register_cpu() used for non-hotplug Changes since RFC v2: * Remove duplicate of the weak generic arch_register_cpu(), spotted by Jonathan Cameron. Add note about initialisation order change. Changes since RFC v3: * Adapt to removal of EXPORT_SYMBOL()s Signed-off-by: James Morse Reviewed-by: Gavin Shan Signed-off-by: "Russell King (Oracle)" Reviewed-by: Jonathan Cameron Reviewed-by: Thomas Gleixner Link: https://lore.kernel.org/r/E1r5R3l-00Cszm-UA@rmk-PC.armlinux.org.uk Signed-off-by: Greg Kroah-Hartman --- arch/x86/Kconfig | 1 + arch/x86/include/asm/cpu.h | 4 ---- arch/x86/kernel/topology.c | 27 ++++----------------------- 3 files changed, 5 insertions(+), 27 deletions(-) (limited to 'arch/x86/Kconfig') diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index dbdcfc708369..8330c4ac26b3 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -148,6 +148,7 @@ config X86 select GENERIC_CLOCKEVENTS_MIN_ADJUST select GENERIC_CMOS_UPDATE select GENERIC_CPU_AUTOPROBE + select GENERIC_CPU_DEVICES select GENERIC_CPU_VULNERABILITIES select GENERIC_EARLY_IOREMAP select GENERIC_ENTRY diff --git a/arch/x86/include/asm/cpu.h b/arch/x86/include/asm/cpu.h index fecc4fe1d68a..f8f9a9b79395 100644 --- a/arch/x86/include/asm/cpu.h +++ b/arch/x86/include/asm/cpu.h @@ -23,10 +23,6 @@ static inline void prefill_possible_map(void) {} #endif /* CONFIG_SMP */ -struct x86_cpu { - struct cpu cpu; -}; - #ifdef CONFIG_HOTPLUG_CPU extern void soft_restart_cpu(void); #endif diff --git a/arch/x86/kernel/topology.c b/arch/x86/kernel/topology.c index fcb62cfdf946..c2ed3145a93b 100644 --- a/arch/x86/kernel/topology.c +++ b/arch/x86/kernel/topology.c @@ -35,36 +35,17 @@ #include #include -static DEFINE_PER_CPU(struct x86_cpu, cpu_devices); - #ifdef CONFIG_HOTPLUG_CPU int arch_register_cpu(int cpu) { - struct x86_cpu *xc = per_cpu_ptr(&cpu_devices, cpu); + struct cpu *c = per_cpu_ptr(&cpu_devices, cpu); - xc->cpu.hotpluggable = cpu > 0; - return register_cpu(&xc->cpu, cpu); + c->hotpluggable = cpu > 0; + return register_cpu(c, cpu); } void arch_unregister_cpu(int num) { - unregister_cpu(&per_cpu(cpu_devices, num).cpu); -} -#else /* CONFIG_HOTPLUG_CPU */ - -int __init arch_register_cpu(int num) -{ - return register_cpu(&per_cpu(cpu_devices, num).cpu, num); + unregister_cpu(&per_cpu(cpu_devices, num)); } #endif /* CONFIG_HOTPLUG_CPU */ - -static int __init topology_init(void) -{ - int i; - - for_each_present_cpu(i) - arch_register_cpu(i); - - return 0; -} -subsys_initcall(topology_init); -- cgit v1.2.3