sf: properly support preservation of inline context

libraries/libstratosphere/source/sf/cmif/sf_cmif_inline_context.cpp

@@ -0,0 +1,67 @@
+/*
+ * Copyright (c) 2018-2020 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/>.
+ */
+#include <stratosphere.hpp>
+
+namespace ams::sf {
+
+    namespace cmif {
+
+        namespace {
+
+            thread_local InlineContext g_inline_context;
+
+            ALWAYS_INLINE void OnSetInlineContext() {
+                /* Ensure that libnx receives the priority value. */
+                ::fsSetPriority(static_cast<::FsPriority>(::ams::sf::GetFsInlineContext()));
+            }
+
+        }
+
+        InlineContext GetInlineContext() {
+            InlineContext ctx;
+            std::memcpy(std::addressof(ctx), std::addressof(::ams::sf::cmif::g_inline_context), sizeof(ctx));
+            return ctx;
+        }
+
+        InlineContext SetInlineContext(InlineContext ctx) {
+            ON_SCOPE_EXIT { OnSetInlineContext(); };
+            static_assert(sizeof(ctx) <= sizeof(g_inline_context));
+
+            InlineContext old_ctx;
+            std::memcpy(std::addressof(old_ctx), std::addressof(g_inline_context), sizeof(old_ctx));
+            std::memcpy(std::addressof(g_inline_context), std::addressof(ctx), sizeof(ctx));
+            return old_ctx;
+        }
+
+    }
+
+    u8 GetFsInlineContext() {
+        u8 ctx;
+        std::memcpy(std::addressof(ctx), std::addressof(cmif::g_inline_context), sizeof(ctx));
+        return ctx;
+    }
+
+    u8 SetFsInlineContext(u8 ctx) {
+        ON_SCOPE_EXIT { cmif::OnSetInlineContext(); };
+        static_assert(sizeof(ctx) <= sizeof(cmif::g_inline_context));
+
+        u8 old_ctx;
+        std::memcpy(std::addressof(old_ctx), std::addressof(cmif::g_inline_context), sizeof(old_ctx));
+        std::memcpy(std::addressof(cmif::g_inline_context), std::addressof(ctx), sizeof(ctx));
+        return old_ctx;
+    }
+
+}