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Kernel: Convert i8042 code to use the ErrorOr pattern more broadly

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Not only does it makes the code more robust and correct as it allows
error propagation, it allows us to enforce timeouts on waiting loops so
we don't hang forever, by waiting for the i8042 controller to respond to
us.

Therefore, it makes the i8042 more resilient against faulty hardware and
bad behaving chipsets out there.
This commit is contained in:
Liav A 2022-02-10 10:50:37 +02:00 • committed by Idan Horowitz
parent dc41a0b830
commit 41dae9b3c7
4 changed files with 117 additions and 81 deletions
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133
Kernel/Devices/HID/I8042Controller.cpp
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@ -31,7 +31,7 @@ UNMAP_AFTER_INIT I8042Controller::I8042Controller()
{
}
UNMAP_AFTER_INIT bool I8042Controller::check_existence()
UNMAP_AFTER_INIT bool I8042Controller::check_existence(Badge<HIDManagement>)
{
{
SpinlockLocker lock(m_lock);
@ -50,59 +50,60 @@ UNMAP_AFTER_INIT bool I8042Controller::check_existence()
}
}
UNMAP_AFTER_INIT void I8042Controller::detect_devices()
UNMAP_AFTER_INIT ErrorOr<void> I8042Controller::detect_devices()
{
if (!check_existence())
return;
u8 configuration;
{
SpinlockLocker lock(m_lock);
drain_output_buffer();
TRY(drain_output_buffer());
do_wait_then_write(I8042Port::Command, I8042Command::DisableFirstPS2Port);
do_wait_then_write(I8042Port::Command, I8042Command::DisableSecondPS2Port); // ignored if it doesn't exist
TRY(do_wait_then_write(I8042Port::Command, I8042Command::DisableFirstPS2Port));
TRY(do_wait_then_write(I8042Port::Command, I8042Command::DisableSecondPS2Port)); // ignored if it doesn't exist
do_wait_then_write(I8042Port::Command, I8042Command::ReadConfiguration);
configuration = do_wait_then_read(I8042Port::Buffer);
do_wait_then_write(I8042Port::Command, I8042Command::WriteConfiguration);
TRY(do_wait_then_write(I8042Port::Command, I8042Command::ReadConfiguration));
configuration = TRY(do_wait_then_read(I8042Port::Buffer));
TRY(do_wait_then_write(I8042Port::Command, I8042Command::WriteConfiguration));
configuration &= ~I8042ConfigurationFlag::FirstPS2PortInterrupt;
configuration &= ~I8042ConfigurationFlag::SecondPS2PortInterrupt;
do_wait_then_write(I8042Port::Buffer, configuration);
TRY(do_wait_then_write(I8042Port::Buffer, configuration));
m_is_dual_channel = (configuration & I8042ConfigurationFlag::SecondPS2PortClock) != 0;
dbgln("I8042: {} channel controller", m_is_dual_channel ? "Dual" : "Single");
// Perform controller self-test
do_wait_then_write(I8042Port::Command, I8042Command::TestPS2Controller);
if (do_wait_then_read(I8042Port::Buffer) == I8042Response::ControllerTestPassed) {
TRY(do_wait_then_write(I8042Port::Command, I8042Command::TestPS2Controller));
auto self_test_result = TRY(do_wait_then_read(I8042Port::Buffer));
if (self_test_result == I8042Response::ControllerTestPassed) {
// Restore configuration in case the controller reset
do_wait_then_write(I8042Port::Command, I8042Command::WriteConfiguration);
do_wait_then_write(I8042Port::Buffer, configuration);
TRY(do_wait_then_write(I8042Port::Command, I8042Command::WriteConfiguration));
TRY(do_wait_then_write(I8042Port::Buffer, configuration));
} else {
dbgln("I8042: Controller self test failed");
}
// Test ports and enable them if available
do_wait_then_write(I8042Port::Command, I8042Command::TestFirstPS2Port);
m_first_port_available = (do_wait_then_read(I8042Port::Buffer) == 0);
TRY(do_wait_then_write(I8042Port::Command, I8042Command::TestFirstPS2Port));
auto first_port_test_result = TRY(do_wait_then_read(I8042Port::Buffer));
m_first_port_available = (first_port_test_result == 0);
if (m_first_port_available) {
do_wait_then_write(I8042Port::Command, I8042Command::EnableFirstPS2Port);
TRY(do_wait_then_write(I8042Port::Command, I8042Command::EnableFirstPS2Port));
configuration |= I8042ConfigurationFlag::FirstPS2PortInterrupt;
configuration &= ~I8042ConfigurationFlag::FirstPS2PortClock;
} else {
dbgln("I8042: Keyboard port not available");
}
drain_output_buffer();
TRY(drain_output_buffer());
if (m_is_dual_channel) {
do_wait_then_write(I8042Port::Command, I8042Command::TestSecondPS2Port);
m_second_port_available = (do_wait_then_read(I8042Port::Buffer) == 0);
TRY(do_wait_then_write(I8042Port::Command, I8042Command::TestSecondPS2Port));
auto test_second_port_result = TRY(do_wait_then_read(I8042Port::Buffer));
m_second_port_available = (test_second_port_result == 0);
if (m_second_port_available) {
do_wait_then_write(I8042Port::Command, I8042Command::EnableSecondPS2Port);
TRY(do_wait_then_write(I8042Port::Command, I8042Command::EnableSecondPS2Port));
configuration |= I8042ConfigurationFlag::SecondPS2PortInterrupt;
configuration &= ~I8042ConfigurationFlag::SecondPS2PortClock;
} else {
@ -114,8 +115,8 @@ UNMAP_AFTER_INIT void I8042Controller::detect_devices()
if (m_first_port_available || m_second_port_available) {
configuration &= ~I8042ConfigurationFlag::FirstPS2PortClock;
configuration &= ~I8042ConfigurationFlag::SecondPS2PortClock;
do_wait_then_write(I8042Port::Command, I8042Command::WriteConfiguration);
do_wait_then_write(I8042Port::Buffer, configuration);
TRY(do_wait_then_write(I8042Port::Command, I8042Command::WriteConfiguration));
TRY(do_wait_then_write(I8042Port::Buffer, configuration));
}
}
@ -128,8 +129,8 @@ UNMAP_AFTER_INIT void I8042Controller::detect_devices()
configuration &= ~I8042ConfigurationFlag::FirstPS2PortInterrupt;
configuration |= I8042ConfigurationFlag::FirstPS2PortClock;
SpinlockLocker lock(m_lock);
do_wait_then_write(I8042Port::Command, I8042Command::WriteConfiguration);
do_wait_then_write(I8042Port::Buffer, configuration);
TRY(do_wait_then_write(I8042Port::Command, I8042Command::WriteConfiguration));
TRY(do_wait_then_write(I8042Port::Buffer, configuration));
}
}
if (m_second_port_available) {
@ -141,8 +142,8 @@ UNMAP_AFTER_INIT void I8042Controller::detect_devices()
m_second_port_available = false;
configuration |= I8042ConfigurationFlag::SecondPS2PortClock;
SpinlockLocker lock(m_lock);
do_wait_then_write(I8042Port::Command, I8042Command::WriteConfiguration);
do_wait_then_write(I8042Port::Buffer, configuration);
TRY(do_wait_then_write(I8042Port::Command, I8042Command::WriteConfiguration));
TRY(do_wait_then_write(I8042Port::Buffer, configuration));
}
}
}
@ -152,6 +153,7 @@ UNMAP_AFTER_INIT void I8042Controller::detect_devices()
m_keyboard_device->enable_interrupts();
if (m_mouse_device)
m_mouse_device->enable_interrupts();
return {};
}
bool I8042Controller::irq_process_input_buffer(HIDDevice::Type instrument_type)
@ -175,29 +177,39 @@ bool I8042Controller::irq_process_input_buffer(HIDDevice::Type instrument_type)
return false;
}
void I8042Controller::drain_output_buffer()
ErrorOr<void> I8042Controller::drain_output_buffer()
{
for (;;) {
for (int attempt = 0; attempt < 5; attempt++) {
u8 status = IO::in8(I8042Port::Status);
if (!(status & I8042StatusFlag::OutputBuffer))
return;
return {};
IO::in8(I8042Port::Buffer);
IO::delay(100);
}
return Error::from_errno(EBUSY);
}
bool I8042Controller::do_reset_device(HIDDevice::Type device)
ErrorOr<void> I8042Controller::do_reset_device(HIDDevice::Type device)
{
VERIFY(device != HIDDevice::Type::Unknown);
VERIFY(m_lock.is_locked());
VERIFY(!Processor::current_in_irq());
if (do_send_command(device, I8042Command::Reset) != I8042Response::Acknowledge)
return false;
auto reset_result = TRY(do_send_command(device, I8042Command::Reset));
// FIXME: Is this the correct errno value for this?
if (reset_result != I8042Response::Acknowledge)
return Error::from_errno(EIO);
// Wait until we get the self-test result
return do_wait_then_read(I8042Port::Buffer) == I8042Response::Success;
auto self_test_result = TRY(do_wait_then_read(I8042Port::Buffer));
// FIXME: Is this the correct errno value for this?
if (self_test_result != I8042Response::Success)
return Error::from_errno(EIO);
return {};
}
u8 I8042Controller::do_send_command(HIDDevice::Type device, u8 command)
ErrorOr<u8> I8042Controller::do_send_command(HIDDevice::Type device, u8 command)
{
VERIFY(device != HIDDevice::Type::Unknown);
VERIFY(m_lock.is_locked());
@ -207,20 +219,20 @@ u8 I8042Controller::do_send_command(HIDDevice::Type device, u8 command)
return do_write_to_device(device, command);
}
u8 I8042Controller::do_send_command(HIDDevice::Type device, u8 command, u8 data)
ErrorOr<u8> I8042Controller::do_send_command(HIDDevice::Type device, u8 command, u8 data)
{
VERIFY(device != HIDDevice::Type::Unknown);
VERIFY(m_lock.is_locked());
VERIFY(!Processor::current_in_irq());
u8 response = do_write_to_device(device, command);
u8 response = TRY(do_write_to_device(device, command));
if (response == I8042Response::Acknowledge)
response = do_write_to_device(device, data);
response = TRY(do_write_to_device(device, data));
return response;
}
u8 I8042Controller::do_write_to_device(HIDDevice::Type device, u8 data)
ErrorOr<u8> I8042Controller::do_write_to_device(HIDDevice::Type device, u8 data)
{
VERIFY(device != HIDDevice::Type::Unknown);
VERIFY(m_lock.is_locked());
@ -231,50 +243,56 @@ u8 I8042Controller::do_write_to_device(HIDDevice::Type device, u8 data)
u8 response;
do {
if (device != HIDDevice::Type::Keyboard) {
prepare_for_output();
TRY(prepare_for_output());
IO::out8(I8042Port::Command, I8042Command::WriteSecondPS2PortInputBuffer);
}
prepare_for_output();
TRY(prepare_for_output());
IO::out8(I8042Port::Buffer, data);
response = do_wait_then_read(I8042Port::Buffer);
response = TRY(do_wait_then_read(I8042Port::Buffer));
} while (response == I8042Response::Resend && ++attempts < 3);
if (attempts >= 3)
dbgln("Failed to write byte to device, gave up");
return response;
}
u8 I8042Controller::do_read_from_device(HIDDevice::Type device)
ErrorOr<u8> I8042Controller::do_read_from_device(HIDDevice::Type device)
{
VERIFY(device != HIDDevice::Type::Unknown);
prepare_for_input(device);
TRY(prepare_for_input(device));
return IO::in8(I8042Port::Buffer);
}
void I8042Controller::prepare_for_input(HIDDevice::Type device)
ErrorOr<void> I8042Controller::prepare_for_input(HIDDevice::Type device)
{
VERIFY(m_lock.is_locked());
u8 const second_port_flag = device == HIDDevice::Type::Keyboard ? 0 : I8042StatusFlag::SecondPS2PortOutputBuffer;
for (;;) {
for (int attempt = 0; attempt < 5; attempt++) {
u8 status = IO::in8(I8042Port::Status);
if (!(status & I8042StatusFlag::OutputBuffer))
if (!(status & I8042StatusFlag::OutputBuffer)) {
IO::delay(100);
continue;
}
if (device == HIDDevice::Type::Unknown)
return;
return {};
if ((status & I8042StatusFlag::SecondPS2PortOutputBuffer) == second_port_flag)
return;
return {};
IO::delay(100);
}
return Error::from_errno(EBUSY);
}
void I8042Controller::prepare_for_output()
ErrorOr<void> I8042Controller::prepare_for_output()
{
VERIFY(m_lock.is_locked());
for (;;) {
for (int attempt = 0; attempt < 5; attempt++) {
u8 status = IO::in8(I8042Port::Status);
if (!(status & I8042StatusFlag::InputBuffer))
return;
return {};
IO::delay(100);
}
return Error::from_errno(EBUSY);
}
UNMAP_AFTER_INIT void I8042Controller::do_write(u8 port, u8 data)
@ -289,17 +307,18 @@ UNMAP_AFTER_INIT u8 I8042Controller::do_read(u8 port)
return IO::in8(port);
}
void I8042Controller::do_wait_then_write(u8 port, u8 data)
ErrorOr<void> I8042Controller::do_wait_then_write(u8 port, u8 data)
{
VERIFY(m_lock.is_locked());
prepare_for_output();
TRY(prepare_for_output());
IO::out8(port, data);
return {};
}
u8 I8042Controller::do_wait_then_read(u8 port)
ErrorOr<u8> I8042Controller::do_wait_then_read(u8 port)
{
VERIFY(m_lock.is_locked());
prepare_for_input(HIDDevice::Type::Unknown);
TRY(prepare_for_input(HIDDevice::Type::Unknown));
return IO::in8(port);
}