alistair23-linux/drivers/s390/char/sclp_quiesce.c
Martin Schwidefsky 8b646bd759 [S390] rework smp code
Define struct pcpu and merge some of the NR_CPUS arrays into it, including
__cpu_logical_map, current_set and smp_cpu_state. Split smp related
functions to those operating on physical cpus and the functions operating
on a logical cpu number. Make the functions for physical cpus use a
pointer to a struct pcpu. This hides the knowledge about cpu addresses in
smp.c, entry[64].S and swsusp_asm64.S, thus remove the sigp.h header.

The PSW restart mechanism is used to start secondary cpus, calling a
function on an online cpu, calling a function on the ipl cpu, and for
the nmi signal. Replace the different assembler functions with a
single function restart_int_handler. The new entry point calls a function
whose pointer is stored in the lowcore of the target cpu and it can wait
for the source cpu to stop. This covers all existing use cases.

Overall the code is now simpler and there are ~380 lines less code.

Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-03-11 11:59:28 -04:00

86 lines
2.2 KiB
C

/*
* drivers/s390/char/sclp_quiesce.c
* signal quiesce handler
*
* (C) Copyright IBM Corp. 1999,2004
* Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
* Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
*/
#include <linux/module.h>
#include <linux/types.h>
#include <linux/cpumask.h>
#include <linux/smp.h>
#include <linux/init.h>
#include <linux/reboot.h>
#include <linux/atomic.h>
#include <asm/ptrace.h>
#include <asm/smp.h>
#include "sclp.h"
static void (*old_machine_restart)(char *);
static void (*old_machine_halt)(void);
static void (*old_machine_power_off)(void);
/* Shutdown handler. Signal completion of shutdown by loading special PSW. */
static void do_machine_quiesce(void)
{
psw_t quiesce_psw;
smp_send_stop();
quiesce_psw.mask =
PSW_MASK_BASE | PSW_MASK_EA | PSW_MASK_BA | PSW_MASK_WAIT;
quiesce_psw.addr = 0xfff;
__load_psw(quiesce_psw);
}
/* Handler for quiesce event. Start shutdown procedure. */
static void sclp_quiesce_handler(struct evbuf_header *evbuf)
{
if (_machine_restart != (void *) do_machine_quiesce) {
old_machine_restart = _machine_restart;
old_machine_halt = _machine_halt;
old_machine_power_off = _machine_power_off;
_machine_restart = (void *) do_machine_quiesce;
_machine_halt = do_machine_quiesce;
_machine_power_off = do_machine_quiesce;
}
ctrl_alt_del();
}
/* Undo machine restart/halt/power_off modification on resume */
static void sclp_quiesce_pm_event(struct sclp_register *reg,
enum sclp_pm_event sclp_pm_event)
{
switch (sclp_pm_event) {
case SCLP_PM_EVENT_RESTORE:
if (old_machine_restart) {
_machine_restart = old_machine_restart;
_machine_halt = old_machine_halt;
_machine_power_off = old_machine_power_off;
old_machine_restart = NULL;
old_machine_halt = NULL;
old_machine_power_off = NULL;
}
break;
case SCLP_PM_EVENT_FREEZE:
case SCLP_PM_EVENT_THAW:
break;
}
}
static struct sclp_register sclp_quiesce_event = {
.receive_mask = EVTYP_SIGQUIESCE_MASK,
.receiver_fn = sclp_quiesce_handler,
.pm_event_fn = sclp_quiesce_pm_event
};
/* Initialize quiesce driver. */
static int __init sclp_quiesce_init(void)
{
return sclp_register(&sclp_quiesce_event);
}
module_init(sclp_quiesce_init);