From 8f2c8791bf71bfc6c3d6e925ab6e09e69a70ee4a Mon Sep 17 00:00:00 2001
From: Masamichi Takagi <masamichi.takagi@riken.jp>
Date: Mon, 15 Jun 2020 12:55:00 +0900
Subject: [PATCH] TO RESET: arm64: enable interrupt on panic

Change-Id: I1ceb321de324f307fc82366b162c72f64184247b
---
 arch/arm64/kernel/cpu.c        | 13 +++++++++++++
 arch/arm64/kernel/irq-gic-v3.c | 21 +++++++++++++++++++++
 arch/x86_64/kernel/cpu.c       | 11 +++++++++++
 lib/abort.c                    |  6 ++++++
 lib/include/ihk/cpu.h          |  3 +++
 5 files changed, 54 insertions(+)

diff --git a/arch/arm64/kernel/cpu.c b/arch/arm64/kernel/cpu.c
index fa53d20f..f9f933c6 100644
--- a/arch/arm64/kernel/cpu.c
+++ b/arch/arm64/kernel/cpu.c
@@ -791,6 +791,19 @@ void cpu_safe_halt(void)
 	cpu_enable_interrupt();
 }
 
+#ifdef ENABLE_FUGAKU_HACKS
+/*@
+  @ assigns \nothing;
+  @ ensures \interrupt_disabled == 0;
+  @*/
+void cpu_halt_panic(void)
+{
+	extern void __cpu_do_idle(void);
+	cpu_enable_interrupt();
+	__cpu_do_idle();
+}
+#endif
+
 #if defined(CONFIG_HAS_NMI)
 #include <arm-gic-v3.h>
 
diff --git a/arch/arm64/kernel/irq-gic-v3.c b/arch/arm64/kernel/irq-gic-v3.c
index c356efb3..113ec4bc 100644
--- a/arch/arm64/kernel/irq-gic-v3.c
+++ b/arch/arm64/kernel/irq-gic-v3.c
@@ -7,6 +7,9 @@
 #include <process.h>
 #include <syscall.h>
 #include <ihk/debug.h>
+#ifdef ENABLE_FUGAKU_HACKS
+#include <ihk/monitor.h>
+#endif
 #include <arch-timer.h>
 #include <cls.h>
 
@@ -313,14 +316,27 @@ void handle_interrupt_gicv3(struct pt_regs *regs)
 	struct cpu_local_var *v = get_this_cpu_local_var();
 	//unsigned long irqflags;
 	int do_check = 0;
+#ifdef ENABLE_FUGAKU_HACKS
+	struct ihk_os_cpu_monitor *monitor = cpu_local_var(monitor);
 
+	++v->in_interrupt;
+#endif
 	irqnr = gic_read_iar();
 	cpu_enable_nmi();
 	set_cputime(from_user ? CPUTIME_MODE_U2K : CPUTIME_MODE_K2K_IN);
 	while (irqnr != ICC_IAR1_EL1_SPURIOUS) {
 		if ((irqnr < 1020) || (irqnr >= 8192)) {
 			gic_write_eoir(irqnr);
+#ifndef ENABLE_FUGAKU_HACKS
 			handle_IPI(irqnr, regs);
+#else
+			/* Once paniced, only allow CPU stop and NMI IRQs */
+			if (monitor->status != IHK_OS_MONITOR_PANIC ||
+					irqnr == INTRID_CPU_STOP ||
+					irqnr == INTRID_MULTI_NMI) {
+				handle_IPI(irqnr, regs);
+			}
+#endif
 		}
 		irqnr = gic_read_iar();
 	}
@@ -335,7 +351,12 @@ void handle_interrupt_gicv3(struct pt_regs *regs)
 	}
 	//ihk_mc_spinlock_unlock(&v->runq_lock, irqflags);
 
+#ifndef ENABLE_FUGAKU_HACKS
 	if (do_check) {
+#else
+	--v->in_interrupt;
+	if (monitor->status != IHK_OS_MONITOR_PANIC && do_check) {
+#endif
 		check_signal(0, regs, 0);
 		schedule();
 	}
diff --git a/arch/x86_64/kernel/cpu.c b/arch/x86_64/kernel/cpu.c
index 0bb0ccf3..ebe9c6d9 100644
--- a/arch/x86_64/kernel/cpu.c
+++ b/arch/x86_64/kernel/cpu.c
@@ -1137,6 +1137,17 @@ void cpu_halt(void)
 	asm volatile("hlt");
 }
 
+#ifdef ENABLE_FUGAKU_HACKS
+/*@
+  @ assigns \nothing;
+  @ ensures \interrupt_disabled == 0;
+  @*/
+void cpu_halt_panic(void)
+{
+    cpu_halt();
+}
+#endif
+
 /*@
   @ assigns \nothing;
   @ ensures \interrupt_disabled == 0;
diff --git a/lib/abort.c b/lib/abort.c
index 18702589..3641829e 100644
--- a/lib/abort.c
+++ b/lib/abort.c
@@ -22,12 +22,18 @@ void panic(const char *msg)
 
 	arch_print_stack();
 
+#ifndef ENABLE_FUGAKU_HACKS
 	/* do not assume anything after this is executed */
 	arch_cpu_stop();
 
 	while (1) {
 		cpu_halt();
 	}
+#else
+	while (1) {
+		cpu_halt_panic();
+	}
+#endif
 }
 
 extern void arch_show_interrupt_context(const void*);
diff --git a/lib/include/ihk/cpu.h b/lib/include/ihk/cpu.h
index f572432e..7a1e499e 100644
--- a/lib/include/ihk/cpu.h
+++ b/lib/include/ihk/cpu.h
@@ -24,6 +24,9 @@ extern int num_processors;
 void cpu_enable_interrupt(void);
 void cpu_disable_interrupt(void);
 void cpu_halt(void);
+#ifdef ENABLE_FUGAKU_HACKS
+void cpu_halt_panic(void);
+#endif
 void cpu_safe_halt(void);
 void cpu_restore_interrupt(unsigned long);
 void cpu_pause(void);