On 11/7/23 18:30, Russell King (Oracle) wrote:
From: James Morse <james.morse@xxxxxxx> To allow ACPI's _STA value to hide CPUs that are present, but not available to online right now due to VMM or firmware policy, the register_cpu() call needs to be made by the ACPI machinery when ACPI is in use. This allows it to hide CPUs that are unavailable from sysfs. Switching to GENERIC_CPU_DEVICES is an intermediate step to allow all five ACPI architectures to be modified at once. Switch over to GENERIC_CPU_DEVICES, and provide an arch_register_cpu() that populates the hotpluggable flag. arch_register_cpu() is also the interface the ACPI machinery expects. The struct cpu in struct cpuinfo_arm64 is never used directly, remove it to use the one GENERIC_CPU_DEVICES provides. This changes the CPUs visible in sysfs from possible to present, but on arm64 smp_prepare_cpus() ensures these are the same. This patch also has the effect of moving the registration of CPUs from subsys to driver core initialisation, prior to any initcalls running. Signed-off-by: James Morse <james.morse@xxxxxxx> Reviewed-by: Russell King (Oracle) <rmk+kernel@xxxxxxxxxxxxxxx> Signed-off-by: Russell King (Oracle) <rmk+kernel@xxxxxxxxxxxxxxx>
Reviewed-by: Shaoqin Huang <shahuang@xxxxxxxxxx>
--- Changes since RFC v2: * Add note about initialisation order change. --- arch/arm64/Kconfig | 1 + arch/arm64/include/asm/cpu.h | 1 - arch/arm64/kernel/setup.c | 13 ++++--------- 3 files changed, 5 insertions(+), 10 deletions(-) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 7b071a00425d..84bce830e365 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -132,6 +132,7 @@ config ARM64 select GENERIC_ARCH_TOPOLOGY select GENERIC_CLOCKEVENTS_BROADCAST select GENERIC_CPU_AUTOPROBE + select GENERIC_CPU_DEVICES select GENERIC_CPU_VULNERABILITIES select GENERIC_EARLY_IOREMAP select GENERIC_IDLE_POLL_SETUP diff --git a/arch/arm64/include/asm/cpu.h b/arch/arm64/include/asm/cpu.h index f3034099fd95..b1e43f56ee46 100644 --- a/arch/arm64/include/asm/cpu.h +++ b/arch/arm64/include/asm/cpu.h @@ -38,7 +38,6 @@ struct cpuinfo_32bit { };struct cpuinfo_arm64 {- struct cpu cpu; struct kobject kobj; u64 reg_ctr; u64 reg_cntfrq; diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c index 417a8a86b2db..165bd2c0dd5a 100644 --- a/arch/arm64/kernel/setup.c +++ b/arch/arm64/kernel/setup.c @@ -402,19 +402,14 @@ static inline bool cpu_can_disable(unsigned int cpu) return false; }-static int __init topology_init(void)+int arch_register_cpu(int num) { - int i; + struct cpu *cpu = &per_cpu(cpu_devices, num);- for_each_possible_cpu(i) {- struct cpu *cpu = &per_cpu(cpu_data.cpu, i); - cpu->hotpluggable = cpu_can_disable(i); - register_cpu(cpu, i); - } + cpu->hotpluggable = cpu_can_disable(num);- return 0;+ return register_cpu(cpu, num); } -subsys_initcall(topology_init);static void dump_kernel_offset(void){
-- Shaoqin
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