From c99a77a0c39c4819f78610e44cbdd9e03f9dac31 Mon Sep 17 00:00:00 2001
From: TuxSH <1922548+TuxSH@users.noreply.github.com>
Date: Tue, 11 Feb 2020 21:41:14 +0000
Subject: [PATCH] thermosphere: interrupt mask guard

---
 .../cpu/hvisor_cpu_interrupt_mask_guard.hpp   | 54 +++++++++++++++++++
 thermosphere/src/hvisor_irq_manager.cpp       | 23 ++++----
 thermosphere/src/hvisor_irq_manager.hpp       | 20 -------
 3 files changed, 63 insertions(+), 34 deletions(-)
 create mode 100644 thermosphere/src/cpu/hvisor_cpu_interrupt_mask_guard.hpp

diff --git a/thermosphere/src/cpu/hvisor_cpu_interrupt_mask_guard.hpp b/thermosphere/src/cpu/hvisor_cpu_interrupt_mask_guard.hpp
new file mode 100644
index 000000000..c75dc7f23
--- /dev/null
+++ b/thermosphere/src/cpu/hvisor_cpu_interrupt_mask_guard.hpp
@@ -0,0 +1,54 @@
+/*
+ * Copyright (c) 2019-2020 Atmosphère-NX
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include "hvisor_cpu_sysreg_general.hpp"
+
+namespace ams::hvisor::cpu {
+
+    static inline u64 MaskIrq()
+    {
+        u64 daif = THERMOSPHERE_GET_SYSREG(daif);
+        THERMOSPHERE_SET_SYSREG_IMM(daifset, BIT(1));
+        return daif;
+    }
+
+    static inline u64 UnmaskIrq()
+    {
+        u64 daif = THERMOSPHERE_GET_SYSREG(daif);
+        THERMOSPHERE_SET_SYSREG_IMM(daifclr, BIT(1));
+        return daif;
+    }
+
+    static inline void RestoreInterruptFlags(u64 flags)
+    {
+        THERMOSPHERE_SET_SYSREG(daif, flags);
+    }
+
+    class InterruptMaskGuard final {
+        NON_COPYABLE(InterruptMaskGuard);
+        NON_MOVEABLE(InterruptMaskGuard);
+        private:
+            u64 m_flags;
+        public:
+            ALWAYS_INLINE InterruptMaskGuard() : m_flags(MaskIrq()) {}
+            ALWAYS_INLINE ~InterruptMaskGuard()
+            {
+                RestoreInterruptFlags(m_flags);
+            }
+    };
+}
diff --git a/thermosphere/src/hvisor_irq_manager.cpp b/thermosphere/src/hvisor_irq_manager.cpp
index bb5d761ab..d0b30f8b9 100644
--- a/thermosphere/src/hvisor_irq_manager.cpp
+++ b/thermosphere/src/hvisor_irq_manager.cpp
@@ -17,7 +17,7 @@
 #include <mutex>
 
 #include "hvisor_irq_manager.hpp"
-
+#include "cpu/hvisor_cpu_interrupt_mask_guard.hpp"
 #include "platform/interrupt_config.h"
 #include "core_ctx.h"
 #include "guest_timers.h"
@@ -159,8 +159,8 @@ namespace ams::hvisor {
 
     void IrqManager::Initialize()
     {
-        u64 flags = MaskIrq();
-        m_lock.lock();
+        cpu::InterruptMaskGuard mg{};
+        std::scoped_lock lk{m_lock};
 
         InitializeGic();
         for (u32 i = 0; i < MaxSgi; i++) {
@@ -170,27 +170,22 @@ namespace ams::hvisor {
         DoConfigureInterrupt(GIC_IRQID_MAINTENANCE, hostPriority, true);
 
         vgicInit();
-
-        m_lock.unlock();
-        RestoreInterruptFlags(flags);
     }
 
     void IrqManager::ConfigureInterrupt(u32 id, u8 prio, bool isLevelSensitive)
     {
-        u64 flags = MaskIrq();
-        m_lock.lock();
+        cpu::InterruptMaskGuard mg{};
+        std::scoped_lock lk{m_lock};
+
         DoConfigureInterrupt(id, prio, isLevelSensitive);
-        m_lock.unlock();
-        RestoreInterruptFlags(flags);
     }
 
     void IrqManager::SetInterruptAffinity(u32 id, u8 affinity)
     {
-        u64 flags = MaskIrq();
-        m_lock.lock();
+        cpu::InterruptMaskGuard mg{};
+        std::scoped_lock lk{m_lock};
+
         DoSetInterruptAffinity(id, affinity);
-        m_lock.unlock();
-        RestoreInterruptFlags(flags);
     }
 
     void IrqManager::HandleInterrupt(ExceptionStackFrame *frame)
diff --git a/thermosphere/src/hvisor_irq_manager.hpp b/thermosphere/src/hvisor_irq_manager.hpp
index 2f37200f0..4099a8c66 100644
--- a/thermosphere/src/hvisor_irq_manager.hpp
+++ b/thermosphere/src/hvisor_irq_manager.hpp
@@ -18,7 +18,6 @@
 
 #include "hvisor_gicv2.hpp"
 #include "hvisor_synchronization.hpp"
-#include "cpu/hvisor_cpu_sysreg_general.hpp"
 #include "memory_map.h"
 
 #include "exceptions.h" // TODO
@@ -93,25 +92,6 @@ namespace ams::hvisor {
                 gicd->sgir = GicV2Distributor::ForwardToAllOthers << 24 | id;
             }
 
-            static u64 MaskIrq()
-            {
-                u64 daif = THERMOSPHERE_GET_SYSREG(daif);
-                THERMOSPHERE_SET_SYSREG_IMM(daifset, BIT(1));
-                return daif;
-            }
-
-            static u64 UnmaskIrq()
-            {
-                u64 daif = THERMOSPHERE_GET_SYSREG(daif);
-                THERMOSPHERE_SET_SYSREG_IMM(daifclr, BIT(1));
-                return daif;
-            }
-
-            static void RestoreInterruptFlags(u64 flags)
-            {
-                THERMOSPHERE_SET_SYSREG(daif, flags);
-            }
-
             static IrqManager &GetInstance() { return instance; }
 
             static void HandleInterrupt(ExceptionStackFrame *frame);