kernel-ark/arch/powerpc/platforms/pseries/offline_states.h
Benjamin Herrenschmidt fa3f82c8bb powerpc/smp: soft-replugged CPUs must go back to start_secondary
Various thing are torn down when a CPU is hot-unplugged. That CPU
is expected to go back to start_secondary when re-plugged to re
initialize everything, such as clock sources, maps, ...

Some implementations just return from cpu_die() callback
in the idle loop when the CPU is "re-plugged". This is not enough.

We fix it using a little asm trampoline which resets the stack
and calls back into start_secondary as if we were all fresh from
boot. The trampoline already existed on ppc64, but we add it for
ppc32

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-01 15:37:09 +11:00

38 lines
889 B
C

#ifndef _OFFLINE_STATES_H_
#define _OFFLINE_STATES_H_
/* Cpu offline states go here */
enum cpu_state_vals {
CPU_STATE_OFFLINE,
CPU_STATE_INACTIVE,
CPU_STATE_ONLINE,
CPU_MAX_OFFLINE_STATES
};
#ifdef CONFIG_HOTPLUG_CPU
extern enum cpu_state_vals get_cpu_current_state(int cpu);
extern void set_cpu_current_state(int cpu, enum cpu_state_vals state);
extern void set_preferred_offline_state(int cpu, enum cpu_state_vals state);
extern void set_default_offline_state(int cpu);
#else
static inline enum cpu_state_vals get_cpu_current_state(int cpu)
{
return CPU_STATE_ONLINE;
}
static inline void set_cpu_current_state(int cpu, enum cpu_state_vals state)
{
}
static inline void set_preferred_offline_state(int cpu, enum cpu_state_vals state)
{
}
static inline void set_default_offline_state(int cpu)
{
}
#endif
extern enum cpu_state_vals get_preferred_offline_state(int cpu);
#endif