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authorJames Morse <james.morse@arm.com>2021-03-29 12:37:04 +0100
committerRussell King (Oracle) <rmk+kernel@armlinux.org.uk>2023-10-30 12:22:21 +0000
commit7022186174115804e16e794a3406c7ee0f677c0c (patch)
tree95158e83e31cea6216aa0b389cbe18e501ce7b8e
parent6751933f7bae26badd6ab2acb9a5d49583503889 (diff)
drivers: base: Allow parts of GENERIC_CPU_DEVICES to be overridden
Architectures often have extra per-cpu work that needs doing before a CPU is registered, often to determine if a CPU is hotpluggable. To allow the ACPI architectures to use GENERIC_CPU_DEVICES, move the cpu_register() call into arch_register_cpu(), which is made __weak so architectures with extra work can override it. This aligns with the way x86, ia64 and loongarch register hotplug CPUs when they become present. Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> --- Changes since RFC: * Dropped __init from x86/ia64 arch_register_cpu() Changes since RFC v2: * Dropped unnecessary Loongarch asm/cpu.h changes
-rw-r--r--drivers/base/cpu.c14
-rw-r--r--include/linux/cpu.h4
2 files changed, 14 insertions, 4 deletions
diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
index 34b48f660b6b..579064fda97b 100644
--- a/drivers/base/cpu.c
+++ b/drivers/base/cpu.c
@@ -525,19 +525,25 @@ bool cpu_is_hotpluggable(unsigned int cpu)
EXPORT_SYMBOL_GPL(cpu_is_hotpluggable);
#ifdef CONFIG_GENERIC_CPU_DEVICES
-static DEFINE_PER_CPU(struct cpu, cpu_devices);
+DEFINE_PER_CPU(struct cpu, cpu_devices);
+
+int __weak arch_register_cpu(int cpu)
+{
+ return register_cpu(&per_cpu(cpu_devices, cpu), cpu);
+}
#endif
static void __init cpu_dev_register_generic(void)
{
-#ifdef CONFIG_GENERIC_CPU_DEVICES
int i;
+ if (!IS_ENABLED(CONFIG_GENERIC_CPU_DEVICES))
+ return;
+
for_each_present_cpu(i) {
- if (register_cpu(&per_cpu(cpu_devices, i), i))
+ if (arch_register_cpu(i))
panic("Failed to register CPU device");
}
-#endif
}
#ifdef CONFIG_GENERIC_CPU_VULNERABILITIES
diff --git a/include/linux/cpu.h b/include/linux/cpu.h
index eb768a866fe3..e117c06e0c6b 100644
--- a/include/linux/cpu.h
+++ b/include/linux/cpu.h
@@ -88,6 +88,10 @@ extern ssize_t arch_cpu_probe(const char *, size_t);
extern ssize_t arch_cpu_release(const char *, size_t);
#endif
+#ifdef CONFIG_GENERIC_CPU_DEVICES
+DECLARE_PER_CPU(struct cpu, cpu_devices);
+#endif
+
/*
* These states are not related to the core CPU hotplug mechanism. They are
* used by various (sub)architectures to track internal state