#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/workqueue.h>
+#include <linux/time.h>
#include <asm/lowcore.h>
static struct semaphore m_sem;
-extern int css_process_crw(int);
+extern int css_process_crw(int, 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
+static NORET_TYPE 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));
+ for(;;);
}
/*
static int
s390_collect_crw_info(void *param)
{
- struct crw crw;
+ struct crw crw[2];
int ccode, ret, slow;
struct semaphore *sem;
+ unsigned int chain;
sem = (struct semaphore *)param;
/* Set a nice name. */
repeat:
down_interruptible(sem);
slow = 0;
+ chain = 0;
while (1) {
- ccode = stcrw(&crw);
+ if (unlikely(chain > 1)) {
+ struct crw tmp_crw;
+
+ printk(KERN_WARNING"%s: Code does not support more "
+ "than two chained crws; please report to "
+ "linux390@de.ibm.com!\n", __FUNCTION__);
+ ccode = stcrw(&tmp_crw);
+ printk(KERN_WARNING"%s: crw reports slct=%d, oflw=%d, "
+ "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
+ __FUNCTION__, tmp_crw.slct, tmp_crw.oflw,
+ tmp_crw.chn, tmp_crw.rsc, tmp_crw.anc,
+ tmp_crw.erc, tmp_crw.rsid);
+ printk(KERN_WARNING"%s: This was crw number %x in the "
+ "chain\n", __FUNCTION__, chain);
+ if (ccode != 0)
+ break;
+ chain = tmp_crw.chn ? chain + 1 : 0;
+ continue;
+ }
+ ccode = stcrw(&crw[chain]);
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);
+ crw[chain].slct, crw[chain].oflw, crw[chain].chn,
+ crw[chain].rsc, crw[chain].anc, crw[chain].erc,
+ crw[chain].rsid);
/* Check for overflows. */
- if (crw.oflw) {
+ if (crw[chain].oflw) {
pr_debug("%s: crw overflow detected!\n", __FUNCTION__);
css_reiterate_subchannels();
+ chain = 0;
slow = 1;
continue;
}
- switch (crw.rsc) {
+ switch (crw[chain].rsc) {
case CRW_RSC_SCH:
- pr_debug("source is subchannel %04X\n", crw.rsid);
- ret = css_process_crw (crw.rsid);
+ if (crw[0].chn && !chain)
+ break;
+ pr_debug("source is subchannel %04X\n", crw[0].rsid);
+ ret = css_process_crw (crw[0].rsid,
+ chain ? crw[1].rsid : 0);
if (ret == -EAGAIN)
slow = 1;
break;
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) {
+ pr_debug("source is channel path %02X\n", crw[0].rsid);
+ switch (crw[0].erc) {
case CRW_ERC_IPARM: /* Path has come. */
- ret = chp_process_crw(crw.rsid, 1);
+ ret = chp_process_crw(crw[0].rsid, 1);
break;
case CRW_ERC_PERRI: /* Path has gone. */
case CRW_ERC_PERRN:
- ret = chp_process_crw(crw.rsid, 0);
+ ret = chp_process_crw(crw[0].rsid, 0);
break;
default:
pr_debug("Don't know how to handle erc=%x\n",
- crw.erc);
+ crw[0].erc);
ret = 0;
}
if (ret == -EAGAIN)
pr_debug("unknown source\n");
break;
}
+ /* chain is always 0 or 1 here. */
+ chain = crw[chain].chn ? chain + 1 : 0;
}
if (slow)
queue_work(slow_path_wq, &slow_path_work);
return 0;
}
+struct mcck_struct {
+ int kill_task;
+ int channel_report;
+ int warning;
+ unsigned long long mcck_code;
+};
+
+static DEFINE_PER_CPU(struct mcck_struct, cpu_mcck);
+
/*
- * machine check handler.
+ * Main machine check handler function. Will be called with interrupts enabled
+ * or disabled and machine checks enabled or disabled.
*/
void
-s390_do_machine_check(void)
+s390_handle_mcck(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");
+ unsigned long flags;
+ struct mcck_struct mcck;
- if (mci->pd) /* instruction processing damage */
- s390_handle_damage("received instruction processing "
- "damage machine check\n");
+ /*
+ * Disable machine checks and get the current state of accumulated
+ * machine checks. Afterwards delete the old state and enable machine
+ * checks again.
+ */
+ local_irq_save(flags);
+ local_mcck_disable();
+ mcck = __get_cpu_var(cpu_mcck);
+ memset(&__get_cpu_var(cpu_mcck), 0, sizeof(struct mcck_struct));
+ clear_thread_flag(TIF_MCCK_PENDING);
+ local_mcck_enable();
+ local_irq_restore(flags);
- 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 */
+ if (mcck.channel_report)
up(&m_sem);
#ifdef CONFIG_MACHCHK_WARNING
* 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 ? */
+ if (mcck.warning) { /* WARNING pending ? */
static int mchchk_wng_posted = 0;
/*
* Use single machine clear, as we cannot handle smp right now
kill_proc(1, SIGPWR, 1);
}
#endif
+
+ if (mcck.kill_task) {
+ local_irq_enable();
+ printk(KERN_EMERG "mcck: Terminating task because of machine "
+ "malfunction (code 0x%016llx).\n", mcck.mcck_code);
+ printk(KERN_EMERG "mcck: task: %s, pid: %d.\n",
+ current->comm, current->pid);
+ do_exit(SIGSEGV);
+ }
+}
+
+/*
+ * returns 0 if all registers could be validated
+ * returns 1 otherwise
+ */
+static int
+s390_revalidate_registers(struct mci *mci)
+{
+ int kill_task;
+ u64 tmpclock;
+ u64 zero;
+ void *fpt_save_area, *fpt_creg_save_area;
+
+ kill_task = 0;
+ zero = 0;
+ /* General purpose registers */
+ if (!mci->gr)
+ /*
+ * General purpose registers couldn't be restored and have
+ * unknown contents. Process needs to be terminated.
+ */
+ kill_task = 1;
+
+ /* Revalidate floating point registers */
+ if (!mci->fp)
+ /*
+ * Floating point registers can't be restored and
+ * therefore the process needs to be terminated.
+ */
+ kill_task = 1;
+
+#ifndef CONFIG_64BIT
+ asm volatile("ld 0,0(%0)\n"
+ "ld 2,8(%0)\n"
+ "ld 4,16(%0)\n"
+ "ld 6,24(%0)"
+ : : "a" (&S390_lowcore.floating_pt_save_area));
+#endif
+
+ if (MACHINE_HAS_IEEE) {
+#ifdef CONFIG_64BIT
+ fpt_save_area = &S390_lowcore.floating_pt_save_area;
+ fpt_creg_save_area = &S390_lowcore.fpt_creg_save_area;
+#else
+ fpt_save_area = (void *) S390_lowcore.extended_save_area_addr;
+ fpt_creg_save_area = fpt_save_area+128;
+#endif
+ /* Floating point control register */
+ if (!mci->fc) {
+ /*
+ * Floating point control register can't be restored.
+ * Task will be terminated.
+ */
+ asm volatile ("lfpc 0(%0)" : : "a" (&zero), "m" (zero));
+ kill_task = 1;
+
+ }
+ else
+ asm volatile (
+ "lfpc 0(%0)"
+ : : "a" (fpt_creg_save_area));
+
+ asm volatile("ld 0,0(%0)\n"
+ "ld 1,8(%0)\n"
+ "ld 2,16(%0)\n"
+ "ld 3,24(%0)\n"
+ "ld 4,32(%0)\n"
+ "ld 5,40(%0)\n"
+ "ld 6,48(%0)\n"
+ "ld 7,56(%0)\n"
+ "ld 8,64(%0)\n"
+ "ld 9,72(%0)\n"
+ "ld 10,80(%0)\n"
+ "ld 11,88(%0)\n"
+ "ld 12,96(%0)\n"
+ "ld 13,104(%0)\n"
+ "ld 14,112(%0)\n"
+ "ld 15,120(%0)\n"
+ : : "a" (fpt_save_area));
+ }
+
+ /* Revalidate access registers */
+ asm volatile("lam 0,15,0(%0)"
+ : : "a" (&S390_lowcore.access_regs_save_area));
+ if (!mci->ar)
+ /*
+ * Access registers have unknown contents.
+ * Terminating task.
+ */
+ kill_task = 1;
+
+ /* Revalidate control registers */
+ if (!mci->cr)
+ /*
+ * Control registers have unknown contents.
+ * Can't recover and therefore stopping machine.
+ */
+ s390_handle_damage("invalid control registers.");
+ else
+#ifdef CONFIG_64BIT
+ asm volatile("lctlg 0,15,0(%0)"
+ : : "a" (&S390_lowcore.cregs_save_area));
+#else
+ asm volatile("lctl 0,15,0(%0)"
+ : : "a" (&S390_lowcore.cregs_save_area));
+#endif
+
+ /*
+ * We don't even try to revalidate the TOD register, since we simply
+ * can't write something sensible into that register.
+ */
+
+#ifdef CONFIG_64BIT
+ /*
+ * See if we can revalidate the TOD programmable register with its
+ * old contents (should be zero) otherwise set it to zero.
+ */
+ if (!mci->pr)
+ asm volatile("sr 0,0\n"
+ "sckpf"
+ : : : "0", "cc");
+ else
+ asm volatile(
+ "l 0,0(%0)\n"
+ "sckpf"
+ : : "a" (&S390_lowcore.tod_progreg_save_area) : "0", "cc");
+#endif
+
+ /* Revalidate clock comparator register */
+ asm volatile ("stck 0(%1)\n"
+ "sckc 0(%1)"
+ : "=m" (tmpclock) : "a" (&(tmpclock)) : "cc", "memory");
+
+ /* Check if old PSW is valid */
+ if (!mci->wp)
+ /*
+ * Can't tell if we come from user or kernel mode
+ * -> stopping machine.
+ */
+ s390_handle_damage("old psw invalid.");
+
+ if (!mci->ms || !mci->pm || !mci->ia)
+ kill_task = 1;
+
+ return kill_task;
+}
+
+#define MAX_IPD_COUNT 29
+#define MAX_IPD_TIME (5 * 60 * USEC_PER_SEC) /* 5 minutes */
+
+/*
+ * machine check handler.
+ */
+void
+s390_do_machine_check(struct pt_regs *regs)
+{
+ static DEFINE_SPINLOCK(ipd_lock);
+ static unsigned long long last_ipd;
+ static int ipd_count;
+ unsigned long long tmp;
+ struct mci *mci;
+ struct mcck_struct *mcck;
+ int umode;
+
+ mci = (struct mci *) &S390_lowcore.mcck_interruption_code;
+ mcck = &__get_cpu_var(cpu_mcck);
+ umode = user_mode(regs);
+
+ if (mci->sd)
+ /* System damage -> stopping machine */
+ s390_handle_damage("received system damage machine check.");
+
+ if (mci->pd) {
+ if (mci->b) {
+ /* Processing backup -> verify if we can survive this */
+ u64 z_mcic, o_mcic, t_mcic;
+#ifdef CONFIG_64BIT
+ z_mcic = (1ULL<<63 | 1ULL<<59 | 1ULL<<29);
+ o_mcic = (1ULL<<43 | 1ULL<<42 | 1ULL<<41 | 1ULL<<40 |
+ 1ULL<<36 | 1ULL<<35 | 1ULL<<34 | 1ULL<<32 |
+ 1ULL<<30 | 1ULL<<21 | 1ULL<<20 | 1ULL<<17 |
+ 1ULL<<16);
+#else
+ z_mcic = (1ULL<<63 | 1ULL<<59 | 1ULL<<57 | 1ULL<<50 |
+ 1ULL<<29);
+ o_mcic = (1ULL<<43 | 1ULL<<42 | 1ULL<<41 | 1ULL<<40 |
+ 1ULL<<36 | 1ULL<<35 | 1ULL<<34 | 1ULL<<32 |
+ 1ULL<<30 | 1ULL<<20 | 1ULL<<17 | 1ULL<<16);
+#endif
+ t_mcic = *(u64 *)mci;
+
+ if (((t_mcic & z_mcic) != 0) ||
+ ((t_mcic & o_mcic) != o_mcic)) {
+ s390_handle_damage("processing backup machine "
+ "check with damage.");
+ }
+
+ /*
+ * Nullifying exigent condition, therefore we might
+ * retry this instruction.
+ */
+
+ spin_lock(&ipd_lock);
+
+ tmp = get_clock();
+
+ if (((tmp - last_ipd) >> 12) < MAX_IPD_TIME)
+ ipd_count++;
+ else
+ ipd_count = 1;
+
+ last_ipd = tmp;
+
+ if (ipd_count == MAX_IPD_COUNT)
+ s390_handle_damage("too many ipd retries.");
+
+ spin_unlock(&ipd_lock);
+ }
+ else {
+ /* Processing damage -> stopping machine */
+ s390_handle_damage("received instruction processing "
+ "damage machine check.");
+ }
+ }
+ if (s390_revalidate_registers(mci)) {
+ if (umode) {
+ /*
+ * Couldn't restore all register contents while in
+ * user mode -> mark task for termination.
+ */
+ mcck->kill_task = 1;
+ mcck->mcck_code = *(unsigned long long *) mci;
+ set_thread_flag(TIF_MCCK_PENDING);
+ }
+ else
+ /*
+ * Couldn't restore all register contents while in
+ * kernel mode -> stopping machine.
+ */
+ s390_handle_damage("unable to revalidate registers.");
+ }
+
+ if (mci->se)
+ /* Storage error uncorrected */
+ s390_handle_damage("received storage error uncorrected "
+ "machine check.");
+
+ if (mci->ke)
+ /* Storage key-error uncorrected */
+ s390_handle_damage("received storage key-error uncorrected "
+ "machine check.");
+
+ if (mci->ds && mci->fa)
+ /* Storage degradation */
+ s390_handle_damage("received storage degradation machine "
+ "check.");
+
+ if (mci->cp) {
+ /* Channel report word pending */
+ mcck->channel_report = 1;
+ set_thread_flag(TIF_MCCK_PENDING);
+ }
+
+ if (mci->w) {
+ /* Warning pending */
+ mcck->warning = 1;
+ set_thread_flag(TIF_MCCK_PENDING);
+ }
}
/*
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 */
+ ctl_clear_bit(14, 25); /* disable 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
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