1 files changed, 57 insertions, 26 deletions

diff --git a/arch/ia64/kernel/crash.c b/arch/ia64/kernel/crash.c
index f065093..6631a9d 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;
 	}