Pull trivial into release branch

[pandora-kernel.git] / drivers / s390 / s390mach.c

diff --git a/drivers/s390/s390mach.c b/drivers/s390/s390mach.c
index 3bf4666..f99e553 100644 (file)
--- a/drivers/s390/s390mach.c
+++ b/drivers/s390/s390mach.c
@@ -13,6 +13,7 @@
 #include <linux/sched.h>
 #include <linux/errno.h>
 #include <linux/workqueue.h>
+#include <linux/time.h>
 
 #include <asm/lowcore.h>
 
@@ -362,12 +363,19 @@ 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;
@@ -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 */