/*
* drivers/s390/s390mach.c
* S/390 machine check handler
*
* S390 version
* Copyright (C) 2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
* Author(s): Ingo Adlung (adlung@de.ibm.com)
* Martin Schwidefsky (schwidefsky@de.ibm.com)
*/
#include <linux/config.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/workqueue.h>
#include <asm/lowcore.h>
#include "s390mach.h"
#define DBG printk
// #define DBG(args,...) do {} while (0);
static struct semaphore m_sem;
extern int css_process_crw(int);
extern int chsc_process_crw(void);
extern int chp_process_crw(int, int);
extern void css_reiterate_subchannels(void);
extern struct workqueue_struct *slow_path_wq;
extern struct work_struct slow_path_work;
static void
s390_handle_damage(char *msg)
{
printk(KERN_EMERG "%s\n", msg);
#ifdef CONFIG_SMP
smp_send_stop();
#endif
disabled_wait((unsigned long) __builtin_return_address(0));
}
/*
* Retrieve CRWs and call function to handle event.
*
* Note : we currently process CRWs for io and chsc subchannels only
*/
static int
s390_collect_crw_info(void *param)
{
struct crw crw;
int ccode, ret, slow;
struct semaphore *sem;
sem = (struct semaphore *)param;
/* Set a nice name. */
daemonize("kmcheck");
repeat:
down_interruptible(sem);
slow = 0;
while (1) {
ccode = stcrw(&crw);
if (ccode != 0)
break;
DBG(KERN_DEBUG "crw_info : CRW reports slct=%d, oflw=%d, "
"chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
crw.slct, crw.oflw, crw.chn, crw.rsc, crw.anc,
crw.erc, crw.rsid);
/* Check for overflows. */
if (crw.oflw) {
pr_debug("%s: crw overflow detected!\n", __FUNCTION__);
css_reiterate_subchannels();
slow = 1;
continue;
}
switch (crw.rsc) {
case CRW_RSC_SCH:
pr_debug("source is subchannel %04X\n", crw.rsid);
ret = css_process_crw (crw.rsid);
if (ret == -EAGAIN)
slow = 1;
break;
case CRW_RSC_MONITOR:
pr_debug("source is monitoring facility\n");
break;
case CRW_RSC_CPATH:
pr_debug("source is channel path %02X\n", crw.rsid);
switch (crw.erc) {
case CRW_ERC_IPARM: /* Path has come. */
ret = chp_process_crw(crw.rsid, 1);
break;
case CRW_ERC_PERRI: /* Path has gone. */
case CRW_ERC_PERRN:
ret = chp_process_crw(crw.rsid, 0);
break;
default:
pr_debug("Don't know how to handle erc=%x\n",
crw.erc);
ret = 0;
}
if (ret == -EAGAIN)
slow = 1;
break;
case CRW_RSC_CONFIG:
pr_debug("source is configuration-alert facility\n");
break;
case CRW_RSC_CSS:
pr_debug("source is channel subsystem\n");
ret = chsc_process_crw();
if (ret == -EAGAIN)
slow = 1;
break;
default:
pr_debug("unknown source\n");
break;
}
}
if (slow)
queue_work(slow_path_wq, &slow_path_work);
goto repeat;
return 0;
}
/*
* machine check handler.
*/
void
s390_do_machine_check(void)
{
struct mci *mci;
mci = (struct mci *) &S390_lowcore.mcck_interruption_code;
if (mci->sd) /* system damage */
s390_handle_damage("received system damage machine check\n");
if (mci->pd) /* instruction processing damage */
s390_handle_damage("received instruction processing "
"damage machine check\n");
if (mci->se) /* storage error uncorrected */
s390_handle_damage("received storage error uncorrected "
"machine check\n");
if (mci->sc) /* storage error corrected */
printk(KERN_WARNING
"received storage error corrected machine check\n");
if (mci->ke) /* storage key-error uncorrected */
s390_handle_damage("received storage key-error uncorrected "
"machine check\n");
if (mci->ds && mci->fa) /* storage degradation */
s390_handle_damage("received storage degradation machine "
"check\n");
if (mci->cp) /* channel report word pending */
up(&m_sem);
#ifdef CONFIG_MACHCHK_WARNING
/*
* The warning may remain for a prolonged period on the bare iron.
* (actually till the machine is powered off, or until the problem is gone)
* So we just stop listening for the WARNING MCH and prevent continuously
* being interrupted. One caveat is however, that we must do this per
* processor and cannot use the smp version of ctl_clear_bit().
* On VM we only get one interrupt per virtally presented machinecheck.
* Though one suffices, we may get one interrupt per (virtual) processor.
*/
if (mci->w) { /* WARNING pending ? */
static int mchchk_wng_posted = 0;
/*
* Use single machine clear, as we cannot handle smp right now
*/
__ctl_clear_bit(14, 24); /* Disable WARNING MCH */
if (xchg(&mchchk_wng_posted, 1) == 0)
kill_proc(1, SIGPWR, 1);
}
#endif
}
/*
* s390_init_machine_check
*
* initialize machine check handling
*/
static int
machine_check_init(void)
{
init_MUTEX_LOCKED(&m_sem);
ctl_clear_bit(14, 25); /* disable damage MCH */
ctl_set_bit(14, 26); /* enable degradation MCH */
ctl_set_bit(14, 27); /* enable system recovery MCH */
#ifdef CONFIG_MACHCHK_WARNING
ctl_set_bit(14, 24); /* enable warning MCH */
#endif
return 0;
}
/*
* Initialize the machine check handler really early to be able to
* catch all machine checks that happen during boot
*/
arch_initcall(machine_check_init);
/*
* Machine checks for the channel subsystem must be enabled
* after the channel subsystem is initialized
*/
static int __init
machine_check_crw_init (void)
{
kernel_thread(s390_collect_crw_info, &m_sem, CLONE_FS|CLONE_FILES);
ctl_set_bit(14, 28); /* enable channel report MCH */
return 0;
}
device_initcall (machine_check_crw_init);
