From: James Morse james.morse@arm.com
mainline inclusion from mainline-v6.8-rc1 commit db3ba29a8315d89736b8af5c1ad945c9967d7655 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I8XMTL CVE: NA
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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.
This allows topology_init() to be removed.
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 is a subtle change. Originally: - on boot, topology_init() would have marked present CPUs that io_master() is true for as hotplug-incapable. - if a CPU is hotplugged that is an io_master(), it can later be hot-unplugged.
The new behaviour is that any CPU that io_master() is true for will now always be marked as hotplug-incapable, thus even if it was hotplugged, it can no longer be hot-unplugged.
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@arm.com Reviewed-by: Gavin Shan gshan@redhat.com Signed-off-by: "Russell King (Oracle)" rmk+kernel@armlinux.org.uk Reviewed-by: Jonathan Cameron Jonathan.Cameron@huawei.com Reviewed-by: Thomas Gleixner tglx@linutronix.de Link: https://lore.kernel.org/r/E1r5R41-00Ct04-Bg@rmk-PC.armlinux.org.uk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: liwei liwei728@huawei.com --- arch/loongarch/Kconfig | 1 + arch/loongarch/kernel/topology.c | 29 ++--------------------------- 2 files changed, 3 insertions(+), 27 deletions(-)
diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig index 54e59e87141e..12f5fcb630a7 100644 --- a/arch/loongarch/Kconfig +++ b/arch/loongarch/Kconfig @@ -72,6 +72,7 @@ config LOONGARCH select GENERIC_CLOCKEVENTS select GENERIC_CMOS_UPDATE select GENERIC_CPU_AUTOPROBE + select GENERIC_CPU_DEVICES select GENERIC_ENTRY select GENERIC_GETTIMEOFDAY select GENERIC_IOREMAP if !ARCH_IOREMAP diff --git a/arch/loongarch/kernel/topology.c b/arch/loongarch/kernel/topology.c index ae860fe81536..7dfb46c68f58 100644 --- a/arch/loongarch/kernel/topology.c +++ b/arch/loongarch/kernel/topology.c @@ -10,20 +10,13 @@
#include <acpi/processor.h>
-static DEFINE_PER_CPU(struct cpu, cpu_devices); - #ifdef CONFIG_HOTPLUG_CPU int arch_register_cpu(int cpu) { - int ret; struct cpu *c = &per_cpu(cpu_devices, cpu);
- c->hotpluggable = 1; - ret = register_cpu(c, cpu); - if (ret < 0) - pr_warn("register_cpu %d failed (%d)\n", cpu, ret); - - return ret; + c->hotpluggable = !io_master(cpu); + return register_cpu(c, cpu); }
void arch_unregister_cpu(int cpu) @@ -34,21 +27,3 @@ void arch_unregister_cpu(int cpu) unregister_cpu(c); } #endif - -static int __init topology_init(void) -{ - int i, ret; - - for_each_present_cpu(i) { - struct cpu *c = &per_cpu(cpu_devices, i); - - c->hotpluggable = !io_master(i); - ret = register_cpu(c, i); - if (ret < 0) - pr_warn("topology_init: register_cpu %d failed (%d)\n", i, ret); - } - - return 0; -} - -subsys_initcall(topology_init);