From 4ad8dad416460f347e93e30f652a9b4216691a11 Mon Sep 17 00:00:00 2001
From: Michael Scire <SciresM@gmail.com>
Date: Mon, 28 Mar 2022 00:00:36 -0700
Subject: [PATCH] os: add DetachIoRegionHandle

---
 .../stratosphere/os/os_io_region_api.hpp      |  1 +
 .../stratosphere/os/os_io_region_types.hpp    |  1 +
 .../source/os/os_io_region.cpp                | 22 +++++++++++++++++++
 3 files changed, 24 insertions(+)

diff --git a/libraries/libstratosphere/include/stratosphere/os/os_io_region_api.hpp b/libraries/libstratosphere/include/stratosphere/os/os_io_region_api.hpp
index d2a4f781d..838228a5e 100644
--- a/libraries/libstratosphere/include/stratosphere/os/os_io_region_api.hpp
+++ b/libraries/libstratosphere/include/stratosphere/os/os_io_region_api.hpp
@@ -26,6 +26,7 @@ namespace ams::os {
     Result CreateIoRegion(IoRegionType *io_region, NativeHandle io_pool_handle, uintptr_t address, size_t size, MemoryMapping mapping, MemoryPermission permission);
 
     void AttachIoRegionHandle(IoRegionType *io_region, size_t size, NativeHandle handle, bool managed);
+    os::NativeHandle DetachIoRegionHandle(IoRegionType *io_region);
 
     void DestroyIoRegion(IoRegionType *io_region);
 
diff --git a/libraries/libstratosphere/include/stratosphere/os/os_io_region_types.hpp b/libraries/libstratosphere/include/stratosphere/os/os_io_region_types.hpp
index 172f5e14f..387541afa 100644
--- a/libraries/libstratosphere/include/stratosphere/os/os_io_region_types.hpp
+++ b/libraries/libstratosphere/include/stratosphere/os/os_io_region_types.hpp
@@ -26,6 +26,7 @@ namespace ams::os {
             State_NotInitialized = 0,
             State_Initialized    = 1,
             State_Mapped         = 2,
+            State_Detached       = 3,
         };
 
         NativeHandle handle;
diff --git a/libraries/libstratosphere/source/os/os_io_region.cpp b/libraries/libstratosphere/source/os/os_io_region.cpp
index 368abfca1..04eab10ce 100644
--- a/libraries/libstratosphere/source/os/os_io_region.cpp
+++ b/libraries/libstratosphere/source/os/os_io_region.cpp
@@ -69,6 +69,28 @@ namespace ams::os {
         InitializeIoRegion(io_region, handle, size, managed);
     }
 
+    os::NativeHandle DetachIoRegionHandle(IoRegionType *io_region) {
+        /* Check pre-conditions. */
+        AMS_ASSERT(io_region->state != IoRegionType::State_NotInitialized);
+
+        /* Acquire exclusive access to the io region. */
+        std::scoped_lock lk(util::GetReference(io_region->cs_io_region));
+
+        /* Check that we can detach. */
+        AMS_ASSERT(io_region->state == IoRegionType::State_Initialized);
+
+        /* Set state as detached. */
+        io_region->state = IoRegionType::State_Detached;
+
+        /* Detach the handle. */
+        const auto handle = io_region->handle;
+
+        io_region->handle         = os::InvalidNativeHandle;
+        io_region->handle_managed = false;
+
+        return handle;
+    }
+
     void DestroyIoRegion(IoRegionType *io_region) {
         /* Check pre-conditions. */
         AMS_ASSERT(io_region->state != IoRegionType::State_NotInitialized);