2 files changed, 42 insertions, 7 deletions

diff --git a/arch/ia64/kernel/crash.c b/arch/ia64/kernel/crash.c
index b2a8b3da8af3..9c851b73f276 100644
--- a/arch/ia64/kernel/crash.c
+++ b/arch/ia64/kernel/crash.c
@@ -23,6 +23,7 @@
 int kdump_status[NR_CPUS];
 static atomic_t kdump_cpu_frozen;
 atomic_t kdump_in_progress;
+static int kdump_freeze_monarch;
 static int kdump_on_init = 1;
 static int kdump_on_fatal_mca = 1;
 
@@ -108,6 +109,33 @@ machine_crash_shutdown(struct pt_regs *pt)
          */
         kexec_disable_iosapic();
 #ifdef CONFIG_SMP
+        /*
+         * If kdump_on_init is set and an INIT is asserted here, kdump will
+         * be started again via INIT monarch.
+         */
+        local_irq_disable();
+        ia64_set_psr_mc();      /* mask MCA/INIT */
+        if (atomic_inc_return(&kdump_in_progress) != 1)
+                unw_init_running(kdump_cpu_freeze, NULL);
+
+        /*
+         * Now this cpu is ready for kdump.
+         * Stop all others by IPI or INIT.  They could receive INIT from
+         * outside and might be INIT monarch, but only thing they have to
+         * do is falling into kdump_cpu_freeze().
+         *
+         * If an INIT is asserted here:
+         * - All receivers might be slaves, since some of cpus could already
+         *   be frozen and INIT might be masked on monarch.  In this case,
+         *   all slaves will park in while (monarch_cpu == -1) loop before
+         *   DIE_INIT_SLAVE_ENTER that for waiting monarch enters.
+         *      => TBD: freeze all slaves
+         * - One might be a monarch, but INIT rendezvous will fail since
+         *   at least this cpu already have INIT masked so it never join
+         *   to the rendezvous.  In this case, all slaves and monarch will
+         *   be frozen after timeout of the INIT rendezvous.
+         *      => TBD: freeze them without waiting timeout
+         */
         kdump_smp_send_stop();
         /* not all cpu response to IPI, send INIT to freeze them */
         if (kdump_wait_cpu_freeze() && kdump_on_init)   {
@@ -177,13 +205,18 @@ kdump_init_notifier(struct notifier_block *self, unsigned long val, void *data)
         switch (val) {
         case DIE_INIT_MONARCH_PROCESS:
                 if (kdump_on_init) {
-                        atomic_set(&kdump_in_progress, 1);
+                        if (atomic_inc_return(&kdump_in_progress) != 1)
+                                kdump_freeze_monarch = 1;
                         *(nd->monarch_cpu) = -1;
                 }
                 break;
         case DIE_INIT_MONARCH_LEAVE:
-                if (kdump_on_init)
-                        machine_kdump_on_init();
+                if (kdump_on_init) {
+                        if (kdump_freeze_monarch)
+                                unw_init_running(kdump_cpu_freeze, NULL);
+                        else
+                                machine_kdump_on_init();
+                }
                 break;
         case DIE_INIT_SLAVE_LEAVE:
                 if (atomic_read(&kdump_in_progress))
@@ -196,9 +229,11 @@ kdump_init_notifier(struct notifier_block *self, unsigned long val, void *data)
         case DIE_MCA_MONARCH_LEAVE:
                 /* *(nd->data) indicate if MCA is recoverable */
                 if (kdump_on_fatal_mca && !(*(nd->data))) {
-                        atomic_set(&kdump_in_progress, 1);
-                        *(nd->monarch_cpu) = -1;
-                        machine_kdump_on_init();
+                        if (atomic_inc_return(&kdump_in_progress) == 1) {
+                                *(nd->monarch_cpu) = -1;
+                                machine_kdump_on_init();
+                        }
+                        /* We got fatal MCA while kdump!? No way!! */
                 }
                 break;
         }
diff --git a/arch/ia64/kernel/relocate_kernel.S b/arch/ia64/kernel/relocate_kernel.S
index 903babd22d62..32f6fc131fbe 100644
--- a/arch/ia64/kernel/relocate_kernel.S
+++ b/arch/ia64/kernel/relocate_kernel.S
@@ -52,7 +52,7 @@ GLOBAL_ENTRY(relocate_new_kernel)
         srlz.i
         ;;
         mov ar.rnat=r18
-        rfi
+        rfi                             // note: this unmask MCA/INIT (psr.mc)
         ;;
 1:
         //physical mode code begin