[PATCH 09/21] drivers: base: add arch_cpu_is_hotpluggable()

Russell King (Oracle)
2023-11-21T13:44:44Z

The differences between architecture specific implementations of
arch_register_cpu() are down to whether the CPU is hotpluggable or not.
Rather than overriding the weak version of arch_register_cpu(), provide
a function that can be used to provide this detail instead.

Reviewed-by: Shaoqin Huang <shahuang@redhat.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
---
drivers/base/cpu.c | 11 ++++++++++-
include/linux/cpu.h | 1 +
2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
index 58bb86091b34..221ffbeb1c9b 100644
--- a/drivers/base/cpu.c
+++ b/drivers/base/cpu.c
@@ -527,9 +527,18 @@ EXPORT_SYMBOL_GPL(cpu_is_hotpluggable);
#ifdef CONFIG_GENERIC_CPU_DEVICES
DEFINE_PER_CPU(struct cpu, cpu_devices);

+bool __weak arch_cpu_is_hotpluggable(int cpu)
+{
+ return false;
+}
+
int __weak arch_register_cpu(int cpu)
{
- return register_cpu(&per_cpu(cpu_devices, cpu), cpu);
+ struct cpu *c = &per_cpu(cpu_devices, cpu);
+
+ c->hotpluggable = arch_cpu_is_hotpluggable(cpu);
+
+ return register_cpu(c, cpu);
}

#ifdef CONFIG_HOTPLUG_CPU
diff --git a/include/linux/cpu.h b/include/linux/cpu.h
index 1e982d63eae8..dcb89c987164 100644
--- a/include/linux/cpu.h
+++ b/include/linux/cpu.h
@@ -80,6 +80,7 @@ extern __printf(4, 5)
struct device *cpu_device_create(struct device *parent, void *drvdata,
const struct attribute_group **groups,
const char *fmt, ...);
+extern bool arch_cpu_is_hotpluggable(int cpu);
extern int arch_register_cpu(int cpu);
extern void arch_unregister_cpu(int cpu);
#ifdef CONFIG_HOTPLUG_CPU
--
2.30.2