1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162

/// The configuration of the port.
pub trait ThreadingOptions {}

/// An abstract interface to an interrupt controller. Implemented by
/// [`use_gic!`].
pub trait InterruptController {
    /// Initialize the driver. This will be called just before entering
    /// [`PortToKernel::boot`].
    ///
    /// [`PortToKernel::boot`]: r3::kernel::PortToKernel::boot
    ///
    /// # Safety
    ///
    /// This is only intended to be called by the port.
    unsafe fn init() {}

    /// Get the currently signaled interrupt and acknowledge it.
    ///
    /// # Safety
    ///
    /// This is only intended to be called by the port in an IRQ handler.
    unsafe fn acknowledge_interrupt() -> Option<r3::kernel::InterruptNum>;

    /// Notify that the kernel has completed the processing of the specified
    /// interrupt.
    ///
    /// # Safety
    ///
    /// This is only intended to be called by the port in an IRQ handler.
    unsafe fn end_interrupt(num: r3::kernel::InterruptNum);
}

/// An abstract inferface to a port timer driver. Implemented by
/// [`use_sp804!`].
pub trait Timer {
    /// Initialize the driver. This will be called just before entering
    /// [`PortToKernel::boot`].
    ///
    /// [`PortToKernel::boot`]: r3::kernel::PortToKernel::boot
    ///
    /// # Safety
    ///
    /// This is only intended to be called by the port.
    unsafe fn init() {}
}

/// Defines the entry points of a port instantiation. Implemented by
/// [`use_port!`].
pub trait EntryPoint {
    /// Proceed with the boot process.
    ///
    /// # Safety
    ///
    ///  - The processor should be in Supervisor mode.
    ///  - This method hasn't been entered yet.
    ///
    unsafe fn start() -> !;

    /// The IRQ handler.
    ///
    /// # Safety
    ///
    ///  - The processor should be in IRQ mode.
    ///  - IRQs should be masked.
    ///  - The register state of the background context should be preserved so
    ///    that the handler can restore it later.
    ///
    unsafe fn irq_entry() -> !;
}

/// Define a system type implementing [`PortThreading`] and [`EntryPoint`].
/// **Requires [`ThreadingOptions`], [`InterruptController`], and [`Timer`].**
///
/// [`PortThreading`]: r3::kernel::PortThreading
#[macro_export]
macro_rules! use_port {
    (unsafe $vis:vis struct $sys:ident) => {
        $vis struct $sys;

        mod port_arm_impl {
            use super::$sys;
            use $crate::r3::kernel::{
                ClearInterruptLineError, EnableInterruptLineError, InterruptNum, InterruptPriority,
                PendInterruptLineError, Port, QueryInterruptLineError, SetInterruptLinePriorityError,
                TaskCb, PortToKernel, PortInterrupts, PortThreading, UTicks, PortTimer,
            };
            use $crate::core::ops::Range;
            use $crate::threading::{
                imp::{State, TaskState, PortInstance},
                cfg::{ThreadingOptions, EntryPoint},
            };

            pub(super) static PORT_STATE: State = State::new();

            unsafe impl PortInstance for $sys {
                #[inline(always)]
                fn port_state() -> &'static State {
                    &PORT_STATE
                }
            }

            impl EntryPoint for $sys {
                unsafe fn start() -> !{
                    unsafe { PORT_STATE.port_boot::<Self>() };
                }

                #[inline(always)]
                unsafe fn irq_entry() -> ! {
                    unsafe { State::irq_entry::<Self>() };
                }
            }

            // Assume `$sys: Kernel`
            unsafe impl PortThreading for $sys {
                type PortTaskState = TaskState;
                #[allow(clippy::declare_interior_mutable_const)]
                const PORT_TASK_STATE_INIT: Self::PortTaskState =
                    $crate::r3::utils::Init::INIT;

                // The minimum stack size for all tests to pass. I found debug
                // formatting to be particularly memory-hungry.
                const STACK_DEFAULT_SIZE: usize = 2048;

                unsafe fn dispatch_first_task() -> ! {
                    PORT_STATE.dispatch_first_task::<Self>()
                }

                unsafe fn yield_cpu() {
                    PORT_STATE.yield_cpu::<Self>()
                }

                unsafe fn exit_and_dispatch(task: &'static TaskCb<Self>) -> ! {
                    PORT_STATE.exit_and_dispatch::<Self>(task);
                }

                #[inline(always)]
                unsafe fn enter_cpu_lock() {
                    PORT_STATE.enter_cpu_lock::<Self>()
                }

                #[inline(always)]
                unsafe fn leave_cpu_lock() {
                    PORT_STATE.leave_cpu_lock::<Self>()
                }

                unsafe fn initialize_task_state(task: &'static TaskCb<Self>) {
                    PORT_STATE.initialize_task_state::<Self>(task)
                }

                fn is_cpu_lock_active() -> bool {
                    PORT_STATE.is_cpu_lock_active::<Self>()
                }

                fn is_task_context() -> bool {
                    PORT_STATE.is_task_context::<Self>()
                }
            }
        }

        const _: () = $crate::threading::imp::validate::<$sys>();
    };
}