Kernel: Wrap HIDManagement keymap data in SpinlockProtected

This serializes access to the current keymap data everywhere in the
kernel, allowing to mark sys$setkeymap() as not needing the big lock.

2 files changed, 34 insertions, 20 deletions

diff --git a/Kernel/Devices/HID/HIDManagement.cpp b/Kernel/Devices/HID/HIDManagement.cpp
index 1d45324d0e..084f0befc6 100644
--- a/Kernel/Devices/HID/HIDManagement.cpp
+++ b/Kernel/Devices/HID/HIDManagement.cpp
@@ -86,17 +86,23 @@ size_t HIDManagement::generate_minor_device_number_for_keyboard()
     return m_keyboard_minor_number++;
 }
 
+UNMAP_AFTER_INIT HIDManagement::KeymapData::KeymapData()
+    : character_map_name(KString::must_create("en-us"sv))
+    , character_map(DEFAULT_CHARACTER_MAP)
+{
+}
+
 UNMAP_AFTER_INIT HIDManagement::HIDManagement()
-    : m_character_map_name(KString::must_create("en-us"sv))
-    , m_character_map(DEFAULT_CHARACTER_MAP)
 {
 }
 
 void HIDManagement::set_maps(NonnullOwnPtr<KString> character_map_name, Keyboard::CharacterMapData const& character_map_data)
 {
-    m_character_map_name = move(character_map_name);
-    m_character_map = character_map_data;
-    dbgln("New Character map '{}' passed in by client.", m_character_map_name);
+    m_keymap_data.with([&](auto& keymap_data) {
+        keymap_data.character_map_name = move(character_map_name);
+        keymap_data.character_map = character_map_data;
+        dbgln("New Character map '{}' passed in by client.", keymap_data.character_map_name);
+    });
 }
 
 UNMAP_AFTER_INIT ErrorOr<void> HIDManagement::enumerate()
@@ -150,17 +156,19 @@ u32 HIDManagement::get_char_from_character_map(KeyEvent event) const
     auto index = event.scancode & 0xFF; // Index is last byte of scan code.
     auto caps_lock_on = event.caps_lock_on;
 
-    u32 code_point;
-    if (modifiers & Mod_Alt)
-        code_point = m_character_map.alt_map[index];
-    else if ((modifiers & Mod_Shift) && (modifiers & Mod_AltGr))
-        code_point = m_character_map.shift_altgr_map[index];
-    else if (modifiers & Mod_Shift)
-        code_point = m_character_map.shift_map[index];
-    else if (modifiers & Mod_AltGr)
-        code_point = m_character_map.altgr_map[index];
-    else
-        code_point = m_character_map.map[index];
+    u32 code_point = 0;
+    m_keymap_data.with([&](auto& keymap_data) {
+        if (modifiers & Mod_Alt)
+            code_point = keymap_data.character_map.alt_map[index];
+        else if ((modifiers & Mod_Shift) && (modifiers & Mod_AltGr))
+            code_point = keymap_data.character_map.shift_altgr_map[index];
+        else if (modifiers & Mod_Shift)
+            code_point = keymap_data.character_map.shift_map[index];
+        else if (modifiers & Mod_AltGr)
+            code_point = keymap_data.character_map.altgr_map[index];
+        else
+            code_point = keymap_data.character_map.map[index];
+    });
 
     if (caps_lock_on && (modifiers == 0 || modifiers == Mod_Shift)) {
         if (code_point >= 'a' && code_point <= 'z')
diff --git a/Kernel/Devices/HID/HIDManagement.h b/Kernel/Devices/HID/HIDManagement.h
index 5201fb9891..691fe3d476 100644
--- a/Kernel/Devices/HID/HIDManagement.h
+++ b/Kernel/Devices/HID/HIDManagement.h
@@ -16,6 +16,7 @@
 #include <Kernel/API/KeyCode.h>
 #include <Kernel/API/MousePacket.h>
 #include <Kernel/Locking/Spinlock.h>
+#include <Kernel/Locking/SpinlockProtected.h>
 #include <Kernel/UnixTypes.h>
 #include <LibKeyboard/CharacterMapData.h>
 
@@ -39,8 +40,14 @@ public:
 
     ErrorOr<void> enumerate();
 
-    StringView keymap_name() const { return m_character_map_name->view(); }
-    Keyboard::CharacterMapData const& character_map() const { return m_character_map; }
+    struct KeymapData {
+        KeymapData();
+        NonnullOwnPtr<KString> character_map_name;
+        Keyboard::CharacterMapData character_map;
+    };
+
+    SpinlockProtected<KeymapData>& keymap_data() { return m_keymap_data; }
+
     u32 get_char_from_character_map(KeyEvent) const;
 
     void set_client(KeyboardClient* client) { m_client = client; }
@@ -50,10 +57,9 @@ private:
     size_t generate_minor_device_number_for_mouse();
     size_t generate_minor_device_number_for_keyboard();
 
+    SpinlockProtected<KeymapData> m_keymap_data;
     size_t m_mouse_minor_number { 0 };
     size_t m_keyboard_minor_number { 0 };
-    NonnullOwnPtr<KString> m_character_map_name;
-    Keyboard::CharacterMapData m_character_map;
     KeyboardClient* m_client { nullptr };
     RefPtr<I8042Controller> m_i8042_controller;
     NonnullRefPtrVector<HIDDevice> m_hid_devices;