Kernel+Userland: Provide bytes count for a DisplayConnector framebuffer

This value will be used later on by WindowServer to reject resolutions
that will request a mapping that will overflow the hardware framebuffer
max length.

3 files changed, 3 insertions, 0 deletions

diff --git a/Userland/Libraries/LibC/sys/ioctl_numbers.h b/Userland/Libraries/LibC/sys/ioctl_numbers.h
index c7c596f94f..df044ddf8f 100644
--- a/Userland/Libraries/LibC/sys/ioctl_numbers.h
+++ b/Userland/Libraries/LibC/sys/ioctl_numbers.h
@@ -24,6 +24,7 @@ struct GraphicsConnectorProperties {
     unsigned char flushing_support;
     unsigned char partial_flushing_support;
     unsigned char refresh_rate_support;
+    unsigned max_buffer_bytes;
 };
 
 struct GraphicsHeadModeSetting {
diff --git a/Userland/Services/WindowServer/HardwareScreenBackend.cpp b/Userland/Services/WindowServer/HardwareScreenBackend.cpp
index 9c9a82b60e..dffbc0b7c2 100644
--- a/Userland/Services/WindowServer/HardwareScreenBackend.cpp
+++ b/Userland/Services/WindowServer/HardwareScreenBackend.cpp
@@ -33,6 +33,7 @@ ErrorOr<void> HardwareScreenBackend::open()
     m_can_device_flush_buffers = (properties.partial_flushing_support != 0);
     m_can_device_flush_entire_framebuffer = (properties.flushing_support != 0);
     m_can_set_head_buffer = (properties.doublebuffer_support != 0);
+    m_max_size_in_bytes = properties.max_buffer_bytes;
     return {};
 }
 
diff --git a/Userland/Services/WindowServer/ScreenBackend.h b/Userland/Services/WindowServer/ScreenBackend.h
index 2e014d55ed..14870c1aa3 100644
--- a/Userland/Services/WindowServer/ScreenBackend.h
+++ b/Userland/Services/WindowServer/ScreenBackend.h
@@ -43,6 +43,7 @@ public:
 
     Gfx::ARGB32* m_framebuffer { nullptr };
     size_t m_size_in_bytes { 0 };
+    size_t m_max_size_in_bytes { 0 };
     size_t m_back_buffer_offset { 0 };
 
     int m_pitch { 0 };