[PATCH] i386: introduce the mechanism of disabling cpu hotplug control
Add 'enable_cpu_hotplug' flag and when cleared, the hotplug control file
("online") will not be added under /sys/devices/system/cpu/cpuX/
Next patch doing PCI quirks will use this.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Cc: "Li, Shaohua" <shaohua.li@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
diff --git a/arch/i386/kernel/topology.c b/arch/i386/kernel/topology.c
index 07d6da3..844c08f 100644
--- a/arch/i386/kernel/topology.c
+++ b/arch/i386/kernel/topology.c
@@ -40,14 +40,18 @@
* restrictions and assumptions in kernel. This basically
* doesnt add a control file, one cannot attempt to offline
* BSP.
+ *
+ * Also certain PCI quirks require not to enable hotplug control
+ * for all CPU's.
*/
- if (!num)
+ if (!num || !enable_cpu_hotplug)
cpu_devices[num].cpu.no_control = 1;
return register_cpu(&cpu_devices[num].cpu, num);
}
#ifdef CONFIG_HOTPLUG_CPU
+int enable_cpu_hotplug = 1;
void arch_unregister_cpu(int num) {
return unregister_cpu(&cpu_devices[num].cpu);
diff --git a/include/asm-i386/cpu.h b/include/asm-i386/cpu.h
index b1bc7b1..9d914e1 100644
--- a/include/asm-i386/cpu.h
+++ b/include/asm-i386/cpu.h
@@ -13,6 +13,9 @@
extern int arch_register_cpu(int num);
#ifdef CONFIG_HOTPLUG_CPU
extern void arch_unregister_cpu(int);
+extern int enable_cpu_hotplug;
+#else
+#define enable_cpu_hotplug 0
#endif
DECLARE_PER_CPU(int, cpu_state);