[PATCH] lockdep: annotate on-stack completions

[powerpc.git] / drivers / s390 / s390mach.c

diff --git a/drivers/s390/s390mach.c b/drivers/s390/s390mach.c
index 3bf4666..ffb3677 100644 (file)
--- a/drivers/s390/s390mach.c
+++ b/drivers/s390/s390mach.c
@@ -8,11 +8,12 @@
  *              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 <linux/time.h>
+#include <linux/kthread.h>
 
 #include <asm/lowcore.h>
 
@@ -55,8 +56,6 @@ s390_collect_crw_info(void *param)
        unsigned int chain;
 
        sem = (struct semaphore *)param;
-       /* Set a nice name. */
-       daemonize("kmcheck");
 repeat:
        down_interruptible(sem);
        slow = 0;
@@ -362,16 +361,25 @@ s390_revalidate_registers(struct mci *mci)
        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;
 
+       lockdep_off();
+
        mci = (struct mci *) &S390_lowcore.mcck_interruption_code;
        mcck = &__get_cpu_var(cpu_mcck);
        umode = user_mode(regs);
@@ -404,11 +412,27 @@ s390_do_machine_check(struct pt_regs *regs)
                                s390_handle_damage("processing backup machine "
                                                   "check with damage.");
                        }
-                       if (!umode)
-                               s390_handle_damage("processing backup machine "
-                                                  "check in kernel mode.");
-                       mcck->kill_task = 1;
-                       mcck->mcck_code = *(unsigned long long *) mci;
+
+                       /*
+                        * 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 */
@@ -460,6 +484,7 @@ s390_do_machine_check(struct pt_regs *regs)
                mcck->warning = 1;
                set_thread_flag(TIF_MCCK_PENDING);
        }
+       lockdep_on();
 }
 
 /*
@@ -492,7 +517,7 @@ arch_initcall(machine_check_init);
 static int __init
 machine_check_crw_init (void)
 {
-       kernel_thread(s390_collect_crw_info, &m_sem, CLONE_FS|CLONE_FILES);
+       kthread_run(s390_collect_crw_info, &m_sem, "kmcheck");
        ctl_set_bit(14, 28);    /* enable channel report MCH */
        return 0;
 }