diff options
Diffstat (limited to 'arch/s390/kernel/smp.c')
| -rw-r--r-- | arch/s390/kernel/smp.c | 36 |
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(®s->gprs, ¤t_lc->gpregs_save_area, sizeof(regs->gprs)); + memcpy(®s->psw, ¤t_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) { |