Kernel/Graphics: Introduce the DisplayConnector class

The DisplayConnector class is meant to replace the FramebufferDevice
class. The advantage of this class over the FramebufferDevice class is:
1. It removes the mmap interface entirely. This interface is unsafe, as
multiple processes could try to use it, and when switching to and from
text console mode, there's no "good" way to revoke a memory mapping from
this interface, let alone when there are multiple processes that call
this interface. Therefore, in the DisplayConnector class there's no
implementation for this method at all.
2. The class uses a new real-world structure called ModeSetting, which
takes into account the fact that real hardware requires more than width,
height and pitch settings to mode-set the display resolution.
3. The class assumes all instances should supply some sort of EDID,
so it facilitates such mechanism to do so. Even if a given driver does
not know what is the actual EDID, it will ask to create default-generic
EDID blob.
3. This class shifts the responsibilies of switching between console
mode and graphical mode from a GraphicsAdapter to the DisplayConnector
class, so when doing the switch, the GraphicsManagement code actually
asks each DisplayConnector object to do the switch and doesn't rely on
the GraphicsAdapter objects at all.

Kernel/CMakeLists.txt

@@ -80,6 +80,7 @@ set(KERNEL_SOURCES
  Graphics/Console/ContiguousFramebufferConsole.cpp
  Graphics/Console/TextModeConsole.cpp
  Graphics/Console/VGAConsole.cpp
+ Graphics/DisplayConnector.cpp
  Graphics/FramebufferDevice.cpp
  Graphics/GraphicsManagement.cpp
  Graphics/Intel/NativeGraphicsAdapter.cpp

Kernel/Graphics/DisplayConnector.cpp

@@ -0,0 +1,333 @@
+/*
+ * Copyright (c) 2022, Liav A. <[email protected]>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <Kernel/Graphics/DisplayConnector.h>
+#include <Kernel/Graphics/GraphicsManagement.h>
+#include <LibC/sys/ioctl_numbers.h>
+
+namespace Kernel {
+
+DisplayConnector::DisplayConnector()
+ : CharacterDevice(226, GraphicsManagement::the().allocate_minor_device_number())
+{
+}
+
+ErrorOr<Memory::Region*> DisplayConnector::mmap(Process&, OpenFileDescription&, Memory::VirtualRange const&, u64, int, bool)
+{
+ return Error::from_errno(ENOTSUP);
+}
+
+ErrorOr<size_t> DisplayConnector::read(OpenFileDescription&, u64, UserOrKernelBuffer&, size_t)
+{
+ return Error::from_errno(ENOTIMPL);
+}
+ErrorOr<size_t> DisplayConnector::write(OpenFileDescription&, u64 offset, UserOrKernelBuffer const& framebuffer_data, size_t length)
+{
+ SpinlockLocker locker(m_control_lock);
+ // FIXME: We silently ignore the request if we are in console mode.
+ // WindowServer is not ready yet to handle errors such as EBUSY currently.
+ if (console_mode()) {
+ return length;
+ }
+ return write_to_first_surface(offset, framebuffer_data, length);
+}
+
+void DisplayConnector::will_be_destroyed()
+{
+ GraphicsManagement::the().detach_display_connector({}, *this);
+ Device::will_be_destroyed();
+}
+
+void DisplayConnector::after_inserting()
+{
+ Device::after_inserting();
+ GraphicsManagement::the().attach_new_display_connector({}, *this);
+}
+
+bool DisplayConnector::console_mode() const
+{
+ VERIFY(m_control_lock.is_locked());
+ return m_console_mode;
+}
+
+void DisplayConnector::set_display_mode(Badge<GraphicsManagement>, DisplayMode mode)
+{
+ SpinlockLocker locker(m_control_lock);
+ m_console_mode = mode == DisplayMode::Console ? true : false;
+ if (m_console_mode)
+ enable_console();
+ else
+ disable_console();
+}
+
+ErrorOr<void> DisplayConnector::initialize_edid_for_generic_monitor()
+{
+ Array<u8, 128> virtual_monitor_edid = {
+ 0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x00, /* header */
+ 0x0, 0x0, /* manufacturer */
+ 0x00, 0x00, /* product code */
+ 0x00, 0x00, 0x00, 0x00, /* serial number goes here */
+ 0x01, /* week of manufacture */
+ 0x00, /* year of manufacture */
+ 0x01, 0x03, /* EDID version */
+ 0x80, /* capabilities - digital */
+ 0x00, /* horiz. res in cm, zero for projectors */
+ 0x00, /* vert. res in cm */
+ 0x78, /* display gamma (120 == 2.2). */
+ 0xEE, /* features (standby, suspend, off, RGB, std */
+ /* colour space, preferred timing mode) */
+ 0xEE, 0x91, 0xA3, 0x54, 0x4C, 0x99, 0x26, 0x0F, 0x50, 0x54,
+ /* chromaticity for standard colour space. */
+ 0x00, 0x00, 0x00, /* no default timings */
+ 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
+ 0x01, 0x01,
+ 0x01, 0x01, 0x01, 0x01, /* no standard timings */
+ 0x00, 0x00, 0x00, 0x06, 0x00, 0x00, 0x06, 0x00, 0x02, 0x02,
+ 0x02, 0x02,
+ /* descriptor block 1 goes below */
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ /* descriptor block 2, monitor ranges */
+ 0x00, 0x00, 0x00, 0xFD, 0x00,
+ 0x00, 0xC8, 0x00, 0xC8, 0x64, 0x00, 0x0A, 0x20, 0x20, 0x20,
+ 0x20, 0x20,
+ /* 0-200Hz vertical, 0-200KHz horizontal, 1000MHz pixel clock */
+ 0x20,
+ /* descriptor block 3, monitor name */
+ 0x00, 0x00, 0x00, 0xFC, 0x00,
+ 'G', 'e', 'n', 'e', 'r', 'i', 'c', 'S', 'c', 'r', 'e', 'e', 'n',
+ /* descriptor block 4: dummy data */
+ 0x00, 0x00, 0x00, 0x10, 0x00,
+ 0x0A, 0x20, 0x20, 0x20, 0x20, 0x20,
+ 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
+ 0x20,
+ 0x00, /* number of extensions */
+ 0x00 /* checksum goes here */
+ };
+ set_edid_bytes(virtual_monitor_edid);
+ return {};
+}
+
+void DisplayConnector::set_edid_bytes(Array<u8, 128> const& edid_bytes)
+{
+ memcpy((u8*)m_edid_bytes, edid_bytes.data(), sizeof(m_edid_bytes));
+ if (auto parsed_edid = EDID::Parser::from_bytes({ m_edid_bytes, sizeof(m_edid_bytes) }); !parsed_edid.is_error()) {
+ m_edid_parser = parsed_edid.release_value();
+ m_edid_valid = true;
+ } else {
+ dmesgln("DisplayConnector: Print offending EDID");
+ for (size_t x = 0; x < 128; x = x + 16) {
+ dmesgln("{:02x} {:02x} {:02x} {:02x} {:02x} {:02x} {:02x} {:02x} {:02x} {:02x} {:02x} {:02x} {:02x} {:02x} {:02x} {:02x}",
+ m_edid_bytes[x], m_edid_bytes[x + 1], m_edid_bytes[x + 2], m_edid_bytes[x + 3],
+ m_edid_bytes[x + 4], m_edid_bytes[x + 5], m_edid_bytes[x + 6], m_edid_bytes[x + 7],
+ m_edid_bytes[x + 8], m_edid_bytes[x + 9], m_edid_bytes[x + 10], m_edid_bytes[x + 11],
+ m_edid_bytes[x + 12], m_edid_bytes[x + 13], m_edid_bytes[x + 14], m_edid_bytes[x + 15]);
+ }
+ dmesgln("DisplayConnector: Parsing EDID failed: {}", parsed_edid.error());
+ }
+}
+
+ErrorOr<void> DisplayConnector::flush_rectangle(size_t, FBRect const&)
+{
+ return Error::from_errno(ENOTSUP);
+}
+
+DisplayConnector::ModeSetting DisplayConnector::current_mode_setting() const
+{
+ SpinlockLocker locker(m_modeset_lock);
+ return m_current_mode_setting;
+}
+
+ErrorOr<ByteBuffer> DisplayConnector::get_edid() const
+{
+ if (!m_edid_valid)
+ return Error::from_errno(ENOTIMPL);
+ return ByteBuffer::copy(m_edid_bytes, sizeof(m_edid_bytes));
+}
+
+ErrorOr<void> DisplayConnector::ioctl(OpenFileDescription&, unsigned request, Userspace<void*> arg)
+{
+ if (request != FB_IOCTL_GET_HEAD_EDID) {
+ // Allow anyone to query the EDID. Eventually we'll publish the current EDID on /sys
+ // so it doesn't really make sense to require the video pledge to query it.
+ TRY(Process::current().require_promise(Pledge::video));
+ }
+
+ // TODO: We really should have ioctls for destroying resources as well
+ switch (request) {
+ case FB_IOCTL_GET_PROPERTIES: {
+ auto user_properties = static_ptr_cast<FBProperties*>(arg);
+ FBProperties properties {};
+ properties.flushing_support = flush_support();
+ properties.doublebuffer_support = double_framebuffering_capable();
+ properties.partial_flushing_support = partial_flush_support();
+ properties.refresh_rate_support = refresh_rate_support();
+
+ return copy_to_user(user_properties, &properties);
+ }
+ case FB_IOCTL_GET_HEAD_MODE_SETTING: {
+ auto user_head_mode_setting = static_ptr_cast<FBHeadModeSetting*>(arg);
+ FBHeadModeSetting head_mode_setting {};
+ TRY(copy_from_user(&head_mode_setting, user_head_mode_setting));
+ {
+ SpinlockLocker control_locker(m_control_lock);
+ head_mode_setting.horizontal_stride = m_current_mode_setting.horizontal_stride;
+ head_mode_setting.pixel_clock_in_khz = m_current_mode_setting.pixel_clock_in_khz;
+ head_mode_setting.horizontal_active = m_current_mode_setting.horizontal_active;
+ head_mode_setting.horizontal_front_porch_pixels = m_current_mode_setting.horizontal_front_porch_pixels;
+ head_mode_setting.horizontal_sync_time_pixels = m_current_mode_setting.horizontal_sync_time_pixels;
+ head_mode_setting.horizontal_blank_pixels = m_current_mode_setting.horizontal_blank_pixels;
+ head_mode_setting.vertical_active = m_current_mode_setting.vertical_active;
+ head_mode_setting.vertical_front_porch_lines = m_current_mode_setting.vertical_front_porch_lines;
+ head_mode_setting.vertical_sync_time_lines = m_current_mode_setting.vertical_sync_time_lines;
+ head_mode_setting.vertical_blank_lines = m_current_mode_setting.vertical_blank_lines;
+ head_mode_setting.horizontal_offset = m_current_mode_setting.horizontal_offset;
+ head_mode_setting.vertical_offset = m_current_mode_setting.vertical_offset;
+ }
+ return copy_to_user(user_head_mode_setting, &head_mode_setting);
+ }
+ case FB_IOCTL_GET_HEAD_EDID: {
+ auto user_head_edid = static_ptr_cast<FBHeadEDID*>(arg);
+ FBHeadEDID head_edid {};
+ TRY(copy_from_user(&head_edid, user_head_edid));
+
+ auto edid_bytes = TRY(get_edid());
+ if (head_edid.bytes != nullptr) {
+ // Only return the EDID if a buffer was provided. Either way,
+ // we'll write back the bytes_size with the actual size
+ if (head_edid.bytes_size < edid_bytes.size()) {
+ head_edid.bytes_size = edid_bytes.size();
+ TRY(copy_to_user(user_head_edid, &head_edid));
+ return Error::from_errno(EOVERFLOW);
+ }
+ TRY(copy_to_user(head_edid.bytes, (void const*)edid_bytes.data(), edid_bytes.size()));
+ }
+ head_edid.bytes_size = edid_bytes.size();
+ return copy_to_user(user_head_edid, &head_edid);
+ }
+ case FB_IOCTL_SET_HEAD_MODE_SETTING: {
+ auto user_mode_setting = static_ptr_cast<FBHeadModeSetting const*>(arg);
+ auto head_mode_setting = TRY(copy_typed_from_user(user_mode_setting));
+
+ if (head_mode_setting.horizontal_stride < 0)
+ return Error::from_errno(EINVAL);
+ if (head_mode_setting.pixel_clock_in_khz < 0)
+ return Error::from_errno(EINVAL);
+ if (head_mode_setting.horizontal_active < 0)
+ return Error::from_errno(EINVAL);
+ if (head_mode_setting.horizontal_front_porch_pixels < 0)
+ return Error::from_errno(EINVAL);
+ if (head_mode_setting.horizontal_sync_time_pixels < 0)
+ return Error::from_errno(EINVAL);
+ if (head_mode_setting.horizontal_blank_pixels < 0)
+ return Error::from_errno(EINVAL);
+ if (head_mode_setting.vertical_active < 0)
+ return Error::from_errno(EINVAL);
+ if (head_mode_setting.vertical_front_porch_lines < 0)
+ return Error::from_errno(EINVAL);
+ if (head_mode_setting.vertical_sync_time_lines < 0)
+ return Error::from_errno(EINVAL);
+ if (head_mode_setting.vertical_blank_lines < 0)
+ return Error::from_errno(EINVAL);
+ if (head_mode_setting.horizontal_offset < 0)
+ return Error::from_errno(EINVAL);
+ if (head_mode_setting.vertical_offset < 0)
+ return Error::from_errno(EINVAL);
+ {
+ SpinlockLocker control_locker(m_control_lock);
+ ModeSetting requested_mode_setting;
+ requested_mode_setting.horizontal_stride = 0;
+ requested_mode_setting.pixel_clock_in_khz = head_mode_setting.pixel_clock_in_khz;
+ requested_mode_setting.horizontal_active = head_mode_setting.horizontal_active;
+ requested_mode_setting.horizontal_front_porch_pixels = head_mode_setting.horizontal_front_porch_pixels;
+ requested_mode_setting.horizontal_sync_time_pixels = head_mode_setting.horizontal_sync_time_pixels;
+ requested_mode_setting.horizontal_blank_pixels = head_mode_setting.horizontal_blank_pixels;
+ requested_mode_setting.vertical_active = head_mode_setting.vertical_active;
+ requested_mode_setting.vertical_front_porch_lines = head_mode_setting.vertical_front_porch_lines;
+ requested_mode_setting.vertical_sync_time_lines = head_mode_setting.vertical_sync_time_lines;
+ requested_mode_setting.vertical_blank_lines = head_mode_setting.vertical_blank_lines;
+ requested_mode_setting.horizontal_offset = head_mode_setting.horizontal_offset;
+ requested_mode_setting.vertical_offset = head_mode_setting.vertical_offset;
+
+ TRY(set_mode_setting(requested_mode_setting));
+ }
+ return {};
+ }
+
+ case FB_IOCTL_SET_SAFE_HEAD_MODE_SETTING: {
+ SpinlockLocker control_locker(m_control_lock);
+ TRY(set_safe_mode_setting());
+ return {};
+ }
+
+ case FB_IOCTL_SET_HEAD_VERTICAL_OFFSET_BUFFER: {
+ // FIXME: We silently ignore the request if we are in console mode.
+ // WindowServer is not ready yet to handle errors such as EBUSY currently.
+ SpinlockLocker control_locker(m_control_lock);
+ if (console_mode()) {
+ return {};
+ }
+
+ auto user_head_vertical_buffer_offset = static_ptr_cast<FBHeadVerticalOffset const*>(arg);
+ auto head_vertical_buffer_offset = TRY(copy_typed_from_user(user_head_vertical_buffer_offset));
+
+ SpinlockLocker locker(m_modeset_lock);
+
+ if (head_vertical_buffer_offset.offsetted < 0 || head_vertical_buffer_offset.offsetted > 1)
+ return Error::from_errno(EINVAL);
+ TRY(set_y_offset(head_vertical_buffer_offset.offsetted == 0 ? 0 : m_current_mode_setting.vertical_active));
+ if (head_vertical_buffer_offset.offsetted == 0)
+ m_vertical_offsetted = false;
+ else
+ m_vertical_offsetted = true;
+ return {};
+ }
+ case FB_IOCTL_GET_HEAD_VERTICAL_OFFSET_BUFFER: {
+ auto user_head_vertical_buffer_offset = static_ptr_cast<FBHeadVerticalOffset*>(arg);
+ FBHeadVerticalOffset head_vertical_buffer_offset {};
+ TRY(copy_from_user(&head_vertical_buffer_offset, user_head_vertical_buffer_offset));
+
+ head_vertical_buffer_offset.offsetted = m_vertical_offsetted;
+ return copy_to_user(user_head_vertical_buffer_offset, &head_vertical_buffer_offset);
+ }
+ case FB_IOCTL_FLUSH_HEAD_BUFFERS: {
+ if (!partial_flush_support())
+ return Error::from_errno(ENOTSUP);
+ MutexLocker locker(m_flushing_lock);
+ auto user_flush_rects = static_ptr_cast<FBFlushRects const*>(arg);
+ auto flush_rects = TRY(copy_typed_from_user(user_flush_rects));
+ if (Checked<unsigned>::multiplication_would_overflow(flush_rects.count, sizeof(FBRect)))
+ return Error::from_errno(EFAULT);
+ if (flush_rects.count > 0) {
+ for (unsigned i = 0; i < flush_rects.count; i++) {
+ FBRect user_dirty_rect;
+ TRY(copy_from_user(&user_dirty_rect, &flush_rects.rects[i]));
+ {
+ SpinlockLocker control_locker(m_control_lock);
+ if (console_mode())
+ return {};
+ TRY(flush_rectangle(flush_rects.buffer_index, user_dirty_rect));
+ }
+ }
+ }
+ return {};
+ };
+ case FB_IOCTL_FLUSH_HEAD: {
+ // FIXME: We silently ignore the request if we are in console mode.
+ // WindowServer is not ready yet to handle errors such as EBUSY currently.
+ MutexLocker locker(m_flushing_lock);
+ SpinlockLocker control_locker(m_control_lock);
+ if (console_mode())
+ return {};
+ if (!flush_support())
+ return Error::from_errno(ENOTSUP);
+ TRY(flush_first_surface());
+ return {};
+ }
+ }
+ return EINVAL;
+}
+
+}