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Diffstat (limited to 'arch/s390/kernel/smp.c')
-rw-r--r--arch/s390/kernel/smp.c36
1 files changed, 35 insertions, 1 deletions
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index 384a6846a65e..b39f596d71bd 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -90,6 +90,39 @@ static int cpu_stopped(int cpu)
return 0;
}
+void smp_switch_to_ipl_cpu(void (*func)(void *), void *data)
+{
+ struct _lowcore *lc, *current_lc;
+ struct stack_frame *sf;
+ struct pt_regs *regs;
+ unsigned long sp;
+
+ if (smp_processor_id() == 0)
+ func(data);
+ __load_psw_mask(PSW_BASE_BITS | PSW_DEFAULT_KEY);
+ /* Disable lowcore protection */
+ __ctl_clear_bit(0, 28);
+ current_lc = lowcore_ptr[smp_processor_id()];
+ lc = lowcore_ptr[0];
+ if (!lc)
+ lc = current_lc;
+ lc->restart_psw.mask = PSW_BASE_BITS | PSW_DEFAULT_KEY;
+ lc->restart_psw.addr = PSW_ADDR_AMODE | (unsigned long) smp_restart_cpu;
+ if (!cpu_online(0))
+ smp_switch_to_cpu(func, data, 0, stap(), __cpu_logical_map[0]);
+ while (signal_processor(0, sigp_stop_and_store_status) == sigp_busy)
+ cpu_relax();
+ sp = lc->panic_stack;
+ sp -= sizeof(struct pt_regs);
+ regs = (struct pt_regs *) sp;
+ memcpy(&regs->gprs, &current_lc->gpregs_save_area, sizeof(regs->gprs));
+ memcpy(&regs->psw, &current_lc->st_status_fixed_logout, sizeof(psw_t));
+ sp -= STACK_FRAME_OVERHEAD;
+ sf = (struct stack_frame *) sp;
+ sf->back_chain = regs->gprs[15];
+ smp_switch_to_cpu(func, data, sp, stap(), __cpu_logical_map[0]);
+}
+
void smp_send_stop(void)
{
int cpu, rc;
@@ -752,7 +785,8 @@ static ssize_t cpu_configure_store(struct sys_device *dev,
get_online_cpus();
mutex_lock(&smp_cpu_state_mutex);
rc = -EBUSY;
- if (cpu_online(cpu))
+ /* disallow configuration changes of online cpus and cpu 0 */
+ if (cpu_online(cpu) || cpu == 0)
goto out;
rc = 0;
switch (val) {