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![Peter Oberparleiter](/assets/img/avatar_default.png)
Use a bitmap for indicating which subchannels require evaluation instead of allocating memory for each evaluation request. This approach reduces memory consumption during recovery in case of massive evaluation request occurrence and removes the need for memory allocation failure handling. Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
539 lines
13 KiB
C
539 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 */
|
|
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)
|
|
{
|
|
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);
|