1 files changed, 57 insertions, 26 deletions

diff --git a/arch/ia64/kernel/crash.c b/arch/ia64/kernel/crash.c
index f065093f8e9b..6631a9dfafdc 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;
 
@@ -108,10 +109,38 @@ 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 be frozen soon since kdump_in_progress will let
+         *   them into DIE_INIT_SLAVE_LEAVE.
+         * - 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 soon with no wait since the INIT rendezvous is skipped
+         *   by kdump_in_progress.
+         */
         kdump_smp_send_stop();
         /* not all cpu response to IPI, send INIT to freeze them */
-        if (kdump_wait_cpu_freeze() && kdump_on_init)   {
+        if (kdump_wait_cpu_freeze()) {
                 kdump_smp_send_init();
+                /* wait again, don't go ahead if possible */
+                kdump_wait_cpu_freeze();
         }
 #endif
 }
@@ -129,17 +158,17 @@ void
 kdump_cpu_freeze(struct unw_frame_info *info, void *arg)
 {
         int cpuid;
+
         local_irq_disable();
         cpuid = smp_processor_id();
         crash_save_this_cpu();
         current->thread.ksp = (__u64)info->sw - 16;
+
+        ia64_set_psr_mc();      /* mask MCA/INIT and stop reentrance */
+
         atomic_inc(&kdump_cpu_frozen);
         kdump_status[cpuid] = 1;
         mb();
-#ifdef CONFIG_HOTPLUG_CPU
-        if (cpuid != 0)
-                ia64_jump_to_sal(&sal_boot_rendez_state[cpuid]);
-#endif
         for (;;)
                 cpu_relax();
 }
@@ -150,6 +179,20 @@ kdump_init_notifier(struct notifier_block *self, unsigned long val, void *data)
         struct ia64_mca_notify_die *nd;
         struct die_args *args = data;
 
+        if (atomic_read(&kdump_in_progress)) {
+                switch (val) {
+                case DIE_INIT_MONARCH_LEAVE:
+                        if (!kdump_freeze_monarch)
+                                break;
+                        /* fall through */
+                case DIE_INIT_SLAVE_LEAVE:
+                case DIE_INIT_MONARCH_ENTER:
+                case DIE_MCA_RENDZVOUS_LEAVE:
+                        unw_init_running(kdump_cpu_freeze, NULL);
+                        break;
+                }
+        }
+
         if (!kdump_on_init && !kdump_on_fatal_mca)
                 return NOTIFY_DONE;
 
@@ -162,43 +205,31 @@ kdump_init_notifier(struct notifier_block *self, unsigned long val, void *data)
         }
 
         if (val != DIE_INIT_MONARCH_LEAVE &&
-            val != DIE_INIT_SLAVE_LEAVE &&
             val != DIE_INIT_MONARCH_PROCESS &&
-            val != DIE_MCA_RENDZVOUS_LEAVE &&
             val != DIE_MCA_MONARCH_LEAVE)
                 return NOTIFY_DONE;
 
         nd = (struct ia64_mca_notify_die *)args->err;
-        /* Reason code 1 means machine check rendezvous*/
-        if ((val == DIE_INIT_MONARCH_LEAVE || val == DIE_INIT_SLAVE_LEAVE
-            || val == DIE_INIT_MONARCH_PROCESS) && nd->sos->rv_rc == 1)
-                return NOTIFY_DONE;
 
         switch (val) {
         case DIE_INIT_MONARCH_PROCESS:
-                if (kdump_on_init) {
-                        atomic_set(&kdump_in_progress, 1);
-                        *(nd->monarch_cpu) = -1;
+                /* Reason code 1 means machine check rendezvous*/
+                if (kdump_on_init && (nd->sos->rv_rc != 1)) {
+                        if (atomic_inc_return(&kdump_in_progress) != 1)
+                                kdump_freeze_monarch = 1;
                 }
                 break;
         case DIE_INIT_MONARCH_LEAVE:
-                if (kdump_on_init)
+                /* Reason code 1 means machine check rendezvous*/
+                if (kdump_on_init && (nd->sos->rv_rc != 1))
                         machine_kdump_on_init();
                 break;
-        case DIE_INIT_SLAVE_LEAVE:
-                if (atomic_read(&kdump_in_progress))
-                        unw_init_running(kdump_cpu_freeze, NULL);
-                break;
-        case DIE_MCA_RENDZVOUS_LEAVE:
-                if (atomic_read(&kdump_in_progress))
-                        unw_init_running(kdump_cpu_freeze, NULL);
-                break;
         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)
+                                machine_kdump_on_init();
+                        /* We got fatal MCA while kdump!? No way!! */
                 }
                 break;
         }