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Diffstat (limited to 'drivers/s390/s390mach.c')
-rw-r--r--drivers/s390/s390mach.c219
1 files changed, 219 insertions, 0 deletions
diff --git a/drivers/s390/s390mach.c b/drivers/s390/s390mach.c
new file mode 100644
index 000000000000..ffa996c8a908
--- /dev/null
+++ b/drivers/s390/s390mach.c
@@ -0,0 +1,219 @@
+/*
+ * 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);