540 lines
13 KiB
C
540 lines
13 KiB
C
/*
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* drivers/s390/s390mach.c
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* S/390 machine check handler
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*
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* S390 version
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* Copyright (C) 2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
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* Author(s): Ingo Adlung (adlung@de.ibm.com)
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* Martin Schwidefsky (schwidefsky@de.ibm.com)
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*/
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#include <linux/init.h>
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#include <linux/sched.h>
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#include <linux/errno.h>
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#include <linux/workqueue.h>
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#include <linux/time.h>
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#include <linux/device.h>
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#include <linux/kthread.h>
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#include <asm/etr.h>
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#include <asm/lowcore.h>
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#include <asm/cio.h>
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#include "cio/cio.h"
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#include "cio/chsc.h"
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#include "cio/css.h"
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#include "cio/chp.h"
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#include "s390mach.h"
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static struct semaphore m_sem;
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static NORET_TYPE void
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s390_handle_damage(char *msg)
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{
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#ifdef CONFIG_SMP
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smp_send_stop();
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#endif
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disabled_wait((unsigned long) __builtin_return_address(0));
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for(;;);
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}
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/*
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* Retrieve CRWs and call function to handle event.
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*
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* Note : we currently process CRWs for io and chsc subchannels only
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*/
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static int
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s390_collect_crw_info(void *param)
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{
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struct crw crw[2];
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int ccode;
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struct semaphore *sem;
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unsigned int chain;
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sem = (struct semaphore *)param;
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repeat:
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down_interruptible(sem);
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chain = 0;
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while (1) {
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if (unlikely(chain > 1)) {
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struct crw tmp_crw;
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printk(KERN_WARNING"%s: Code does not support more "
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"than two chained crws; please report to "
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"linux390@de.ibm.com!\n", __FUNCTION__);
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ccode = stcrw(&tmp_crw);
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printk(KERN_WARNING"%s: crw reports slct=%d, oflw=%d, "
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"chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
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__FUNCTION__, tmp_crw.slct, tmp_crw.oflw,
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tmp_crw.chn, tmp_crw.rsc, tmp_crw.anc,
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tmp_crw.erc, tmp_crw.rsid);
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printk(KERN_WARNING"%s: This was crw number %x in the "
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"chain\n", __FUNCTION__, chain);
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if (ccode != 0)
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break;
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chain = tmp_crw.chn ? chain + 1 : 0;
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continue;
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}
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ccode = stcrw(&crw[chain]);
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if (ccode != 0)
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break;
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printk(KERN_DEBUG "crw_info : CRW reports slct=%d, oflw=%d, "
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"chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
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crw[chain].slct, crw[chain].oflw, crw[chain].chn,
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crw[chain].rsc, crw[chain].anc, crw[chain].erc,
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crw[chain].rsid);
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/* Check for overflows. */
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if (crw[chain].oflw) {
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pr_debug("%s: crw overflow detected!\n", __FUNCTION__);
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css_schedule_eval_all();
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chain = 0;
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continue;
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}
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switch (crw[chain].rsc) {
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case CRW_RSC_SCH:
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if (crw[0].chn && !chain)
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break;
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pr_debug("source is subchannel %04X\n", crw[0].rsid);
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css_process_crw(crw[0].rsid, chain ? crw[1].rsid : 0);
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break;
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case CRW_RSC_MONITOR:
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pr_debug("source is monitoring facility\n");
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break;
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case CRW_RSC_CPATH:
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pr_debug("source is channel path %02X\n", crw[0].rsid);
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/*
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* Check for solicited machine checks. These are
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* created by reset channel path and need not be
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* reported to the common I/O layer.
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*/
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if (crw[chain].slct) {
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pr_debug("solicited machine check for "
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"channel path %02X\n", crw[0].rsid);
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break;
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}
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switch (crw[0].erc) {
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case CRW_ERC_IPARM: /* Path has come. */
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chp_process_crw(crw[0].rsid, 1);
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break;
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case CRW_ERC_PERRI: /* Path has gone. */
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case CRW_ERC_PERRN:
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chp_process_crw(crw[0].rsid, 0);
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break;
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default:
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pr_debug("Don't know how to handle erc=%x\n",
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crw[0].erc);
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}
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break;
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case CRW_RSC_CONFIG:
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pr_debug("source is configuration-alert facility\n");
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break;
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case CRW_RSC_CSS:
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pr_debug("source is channel subsystem\n");
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chsc_process_crw();
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break;
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default:
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pr_debug("unknown source\n");
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break;
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}
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/* chain is always 0 or 1 here. */
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chain = crw[chain].chn ? chain + 1 : 0;
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}
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goto repeat;
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return 0;
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}
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struct mcck_struct {
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int kill_task;
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int channel_report;
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int warning;
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unsigned long long mcck_code;
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};
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static DEFINE_PER_CPU(struct mcck_struct, cpu_mcck);
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/*
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* Main machine check handler function. Will be called with interrupts enabled
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* or disabled and machine checks enabled or disabled.
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*/
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void
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s390_handle_mcck(void)
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{
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unsigned long flags;
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struct mcck_struct mcck;
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/*
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* Disable machine checks and get the current state of accumulated
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* machine checks. Afterwards delete the old state and enable machine
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* checks again.
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*/
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local_irq_save(flags);
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local_mcck_disable();
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mcck = __get_cpu_var(cpu_mcck);
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memset(&__get_cpu_var(cpu_mcck), 0, sizeof(struct mcck_struct));
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clear_thread_flag(TIF_MCCK_PENDING);
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local_mcck_enable();
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local_irq_restore(flags);
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if (mcck.channel_report)
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up(&m_sem);
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#ifdef CONFIG_MACHCHK_WARNING
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/*
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* The warning may remain for a prolonged period on the bare iron.
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* (actually till the machine is powered off, or until the problem is gone)
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* So we just stop listening for the WARNING MCH and prevent continuously
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* being interrupted. One caveat is however, that we must do this per
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* processor and cannot use the smp version of ctl_clear_bit().
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* On VM we only get one interrupt per virtally presented machinecheck.
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* Though one suffices, we may get one interrupt per (virtual) processor.
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*/
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if (mcck.warning) { /* WARNING pending ? */
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static int mchchk_wng_posted = 0;
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/*
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* Use single machine clear, as we cannot handle smp right now
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*/
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__ctl_clear_bit(14, 24); /* Disable WARNING MCH */
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if (xchg(&mchchk_wng_posted, 1) == 0)
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kill_cad_pid(SIGPWR, 1);
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}
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#endif
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if (mcck.kill_task) {
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local_irq_enable();
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printk(KERN_EMERG "mcck: Terminating task because of machine "
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"malfunction (code 0x%016llx).\n", mcck.mcck_code);
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printk(KERN_EMERG "mcck: task: %s, pid: %d.\n",
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current->comm, current->pid);
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do_exit(SIGSEGV);
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}
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}
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/*
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* returns 0 if all registers could be validated
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* returns 1 otherwise
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*/
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static int
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s390_revalidate_registers(struct mci *mci)
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{
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int kill_task;
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u64 tmpclock;
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u64 zero;
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void *fpt_save_area, *fpt_creg_save_area;
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kill_task = 0;
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zero = 0;
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/* General purpose registers */
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if (!mci->gr)
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/*
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* General purpose registers couldn't be restored and have
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* unknown contents. Process needs to be terminated.
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*/
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kill_task = 1;
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/* Revalidate floating point registers */
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if (!mci->fp)
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/*
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* Floating point registers can't be restored and
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* therefore the process needs to be terminated.
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*/
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kill_task = 1;
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#ifndef CONFIG_64BIT
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asm volatile(
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" ld 0,0(%0)\n"
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" ld 2,8(%0)\n"
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" ld 4,16(%0)\n"
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" ld 6,24(%0)"
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: : "a" (&S390_lowcore.floating_pt_save_area));
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#endif
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if (MACHINE_HAS_IEEE) {
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#ifdef CONFIG_64BIT
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fpt_save_area = &S390_lowcore.floating_pt_save_area;
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fpt_creg_save_area = &S390_lowcore.fpt_creg_save_area;
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#else
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fpt_save_area = (void *) S390_lowcore.extended_save_area_addr;
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fpt_creg_save_area = fpt_save_area+128;
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#endif
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/* Floating point control register */
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if (!mci->fc) {
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/*
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* Floating point control register can't be restored.
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* Task will be terminated.
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*/
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asm volatile("lfpc 0(%0)" : : "a" (&zero), "m" (zero));
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kill_task = 1;
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} else
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asm volatile("lfpc 0(%0)" : : "a" (fpt_creg_save_area));
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asm volatile(
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" ld 0,0(%0)\n"
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" ld 1,8(%0)\n"
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" ld 2,16(%0)\n"
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" ld 3,24(%0)\n"
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" ld 4,32(%0)\n"
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" ld 5,40(%0)\n"
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" ld 6,48(%0)\n"
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" ld 7,56(%0)\n"
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" ld 8,64(%0)\n"
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" ld 9,72(%0)\n"
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" ld 10,80(%0)\n"
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" ld 11,88(%0)\n"
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" ld 12,96(%0)\n"
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" ld 13,104(%0)\n"
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" ld 14,112(%0)\n"
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" ld 15,120(%0)\n"
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: : "a" (fpt_save_area));
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}
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/* Revalidate access registers */
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asm volatile(
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" lam 0,15,0(%0)"
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: : "a" (&S390_lowcore.access_regs_save_area));
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if (!mci->ar)
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/*
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* Access registers have unknown contents.
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* Terminating task.
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*/
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kill_task = 1;
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/* Revalidate control registers */
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if (!mci->cr)
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/*
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* Control registers have unknown contents.
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* Can't recover and therefore stopping machine.
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*/
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s390_handle_damage("invalid control registers.");
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else
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#ifdef CONFIG_64BIT
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asm volatile(
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" lctlg 0,15,0(%0)"
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: : "a" (&S390_lowcore.cregs_save_area));
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#else
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asm volatile(
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" lctl 0,15,0(%0)"
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: : "a" (&S390_lowcore.cregs_save_area));
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#endif
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/*
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* We don't even try to revalidate the TOD register, since we simply
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* can't write something sensible into that register.
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*/
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#ifdef CONFIG_64BIT
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/*
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* See if we can revalidate the TOD programmable register with its
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* old contents (should be zero) otherwise set it to zero.
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*/
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if (!mci->pr)
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asm volatile(
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" sr 0,0\n"
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" sckpf"
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: : : "0", "cc");
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else
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asm volatile(
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" l 0,0(%0)\n"
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" sckpf"
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: : "a" (&S390_lowcore.tod_progreg_save_area)
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: "0", "cc");
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#endif
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/* Revalidate clock comparator register */
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asm volatile(
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" stck 0(%1)\n"
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" sckc 0(%1)"
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: "=m" (tmpclock) : "a" (&(tmpclock)) : "cc", "memory");
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/* Check if old PSW is valid */
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if (!mci->wp)
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/*
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* Can't tell if we come from user or kernel mode
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* -> stopping machine.
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*/
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s390_handle_damage("old psw invalid.");
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if (!mci->ms || !mci->pm || !mci->ia)
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kill_task = 1;
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return kill_task;
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}
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#define MAX_IPD_COUNT 29
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#define MAX_IPD_TIME (5 * 60 * USEC_PER_SEC) /* 5 minutes */
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/*
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* machine check handler.
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*/
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void
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s390_do_machine_check(struct pt_regs *regs)
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{
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static DEFINE_SPINLOCK(ipd_lock);
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static unsigned long long last_ipd;
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static int ipd_count;
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unsigned long long tmp;
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struct mci *mci;
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struct mcck_struct *mcck;
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int umode;
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lockdep_off();
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mci = (struct mci *) &S390_lowcore.mcck_interruption_code;
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mcck = &__get_cpu_var(cpu_mcck);
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umode = user_mode(regs);
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if (mci->sd)
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/* System damage -> stopping machine */
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s390_handle_damage("received system damage machine check.");
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if (mci->pd) {
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if (mci->b) {
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/* Processing backup -> verify if we can survive this */
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u64 z_mcic, o_mcic, t_mcic;
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#ifdef CONFIG_64BIT
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z_mcic = (1ULL<<63 | 1ULL<<59 | 1ULL<<29);
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o_mcic = (1ULL<<43 | 1ULL<<42 | 1ULL<<41 | 1ULL<<40 |
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1ULL<<36 | 1ULL<<35 | 1ULL<<34 | 1ULL<<32 |
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1ULL<<30 | 1ULL<<21 | 1ULL<<20 | 1ULL<<17 |
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1ULL<<16);
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#else
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z_mcic = (1ULL<<63 | 1ULL<<59 | 1ULL<<57 | 1ULL<<50 |
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1ULL<<29);
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o_mcic = (1ULL<<43 | 1ULL<<42 | 1ULL<<41 | 1ULL<<40 |
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1ULL<<36 | 1ULL<<35 | 1ULL<<34 | 1ULL<<32 |
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1ULL<<30 | 1ULL<<20 | 1ULL<<17 | 1ULL<<16);
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#endif
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t_mcic = *(u64 *)mci;
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if (((t_mcic & z_mcic) != 0) ||
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((t_mcic & o_mcic) != o_mcic)) {
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s390_handle_damage("processing backup machine "
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"check with damage.");
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}
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/*
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* Nullifying exigent condition, therefore we might
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* retry this instruction.
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*/
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spin_lock(&ipd_lock);
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tmp = get_clock();
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if (((tmp - last_ipd) >> 12) < MAX_IPD_TIME)
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ipd_count++;
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else
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ipd_count = 1;
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last_ipd = tmp;
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if (ipd_count == MAX_IPD_COUNT)
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s390_handle_damage("too many ipd retries.");
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spin_unlock(&ipd_lock);
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}
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else {
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/* Processing damage -> stopping machine */
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s390_handle_damage("received instruction processing "
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"damage machine check.");
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}
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}
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if (s390_revalidate_registers(mci)) {
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if (umode) {
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/*
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* Couldn't restore all register contents while in
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* user mode -> mark task for termination.
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*/
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mcck->kill_task = 1;
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mcck->mcck_code = *(unsigned long long *) mci;
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set_thread_flag(TIF_MCCK_PENDING);
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}
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else
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/*
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* Couldn't restore all register contents while in
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* kernel mode -> stopping machine.
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*/
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s390_handle_damage("unable to revalidate registers.");
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}
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if (mci->cd) {
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/* Timing facility damage */
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s390_handle_damage("TOD clock damaged");
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}
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if (mci->ed && mci->ec) {
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/* External damage */
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if (S390_lowcore.external_damage_code & (1U << ED_ETR_SYNC))
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etr_sync_check();
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if (S390_lowcore.external_damage_code & (1U << ED_ETR_SWITCH))
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etr_switch_to_local();
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}
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if (mci->se)
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/* Storage error uncorrected */
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s390_handle_damage("received storage error uncorrected "
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"machine check.");
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if (mci->ke)
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/* Storage key-error uncorrected */
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s390_handle_damage("received storage key-error uncorrected "
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"machine check.");
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if (mci->ds && mci->fa)
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/* Storage degradation */
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s390_handle_damage("received storage degradation machine "
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"check.");
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if (mci->cp) {
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/* Channel report word pending */
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mcck->channel_report = 1;
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set_thread_flag(TIF_MCCK_PENDING);
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}
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if (mci->w) {
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/* Warning pending */
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mcck->warning = 1;
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set_thread_flag(TIF_MCCK_PENDING);
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}
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lockdep_on();
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}
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/*
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* s390_init_machine_check
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*
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* initialize machine check handling
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*/
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static int
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machine_check_init(void)
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{
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init_MUTEX_LOCKED(&m_sem);
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ctl_set_bit(14, 25); /* enable external damage MCH */
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ctl_set_bit(14, 27); /* enable system recovery MCH */
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#ifdef CONFIG_MACHCHK_WARNING
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ctl_set_bit(14, 24); /* enable warning MCH */
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#endif
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return 0;
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}
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/*
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* Initialize the machine check handler really early to be able to
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* catch all machine checks that happen during boot
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*/
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arch_initcall(machine_check_init);
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/*
|
|
* Machine checks for the channel subsystem must be enabled
|
|
* after the channel subsystem is initialized
|
|
*/
|
|
static int __init
|
|
machine_check_crw_init (void)
|
|
{
|
|
struct task_struct *task;
|
|
|
|
task = kthread_run(s390_collect_crw_info, &m_sem, "kmcheck");
|
|
if (IS_ERR(task))
|
|
return PTR_ERR(task);
|
|
ctl_set_bit(14, 28); /* enable channel report MCH */
|
|
return 0;
|
|
}
|
|
|
|
device_initcall (machine_check_crw_init);
|