[PATCH v4 2/6] rust: irq: add flags module

[Daniel Almeida]

Manipulating IRQ flags (i.e.: IRQF_*) will soon be necessary, specially to
register IRQ handlers through bindings::request_irq().

Add a kernel::irq::Flags for that purpose.

Signed-off-by: Daniel Almeida <daniel.almeida@xxxxxxxxxxxxx>
---
 rust/kernel/irq.rs       |   3 ++
 rust/kernel/irq/flags.rs | 102 +++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 105 insertions(+)

diff --git a/rust/kernel/irq.rs b/rust/kernel/irq.rs
index fae7b15effc80c936d6bffbd5b4150000d6c2898..9abd9a6dc36f3e3ecc1f92ad7b0040176b56a079 100644
--- a/rust/kernel/irq.rs
+++ b/rust/kernel/irq.rs
@@ -9,3 +9,6 @@
 //! drivers to register a handler for a given IRQ line.
 //!
 //! C header: [`include/linux/device.h`](srctree/include/linux/interrupt.h)
+
+/// Flags to be used when registering IRQ handlers.
+pub mod flags;
diff --git a/rust/kernel/irq/flags.rs b/rust/kernel/irq/flags.rs
new file mode 100644
index 0000000000000000000000000000000000000000..3cfaef65ae14f6c02f55ebcf4d52450c0052df30
--- /dev/null
+++ b/rust/kernel/irq/flags.rs
@@ -0,0 +1,102 @@
+// SPDX-License-Identifier: GPL-2.0
+// SPDX-FileCopyrightText: Copyright 2025 Collabora ltd.
+
+use crate::bindings;
+
+/// Flags to be used when registering IRQ handlers.
+///
+/// They can be combined with the operators `|`, `&`, and `!`.
+#[derive(Clone, Copy, PartialEq, Eq)]
+pub struct Flags(u64);
+
+impl Flags {
+    pub(crate) fn into_inner(self) -> u64 {
+        self.0
+    }
+}
+
+impl core::ops::BitOr for Flags {
+    type Output = Self;
+    fn bitor(self, rhs: Self) -> Self::Output {
+        Self(self.0 | rhs.0)
+    }
+}
+
+impl core::ops::BitAnd for Flags {
+    type Output = Self;
+    fn bitand(self, rhs: Self) -> Self::Output {
+        Self(self.0 & rhs.0)
+    }
+}
+
+impl core::ops::Not for Flags {
+    type Output = Self;
+    fn not(self) -> Self::Output {
+        Self(!self.0)
+    }
+}
+
+/// Use the interrupt line as already configured.
+pub const TRIGGER_NONE: Flags = Flags(bindings::IRQF_TRIGGER_NONE as u64);
+
+/// The interrupt is triggered when the signal goes from low to high.
+pub const TRIGGER_RISING: Flags = Flags(bindings::IRQF_TRIGGER_RISING as u64);
+
+/// The interrupt is triggered when the signal goes from high to low.
+pub const TRIGGER_FALLING: Flags = Flags(bindings::IRQF_TRIGGER_FALLING as u64);
+
+/// The interrupt is triggered while the signal is held high.
+pub const TRIGGER_HIGH: Flags = Flags(bindings::IRQF_TRIGGER_HIGH as u64);
+
+/// The interrupt is triggered while the signal is held low.
+pub const TRIGGER_LOW: Flags = Flags(bindings::IRQF_TRIGGER_LOW as u64);
+
+/// Allow sharing the irq among several devices.
+pub const SHARED: Flags = Flags(bindings::IRQF_SHARED as u64);
+
+/// Set by callers when they expect sharing mismatches to occur.
+pub const PROBE_SHARED: Flags = Flags(bindings::IRQF_PROBE_SHARED as u64);
+
+/// Flag to mark this interrupt as timer interrupt.
+pub const TIMER: Flags = Flags(bindings::IRQF_TIMER as u64);
+
+/// Interrupt is per cpu.
+pub const PERCPU: Flags = Flags(bindings::IRQF_PERCPU as u64);
+
+/// Flag to exclude this interrupt from irq balancing.
+pub const NOBALANCING: Flags = Flags(bindings::IRQF_NOBALANCING as u64);
+
+/// Interrupt is used for polling (only the interrupt that is registered
+/// first in a shared interrupt is considered for performance reasons).
+pub const IRQPOLL: Flags = Flags(bindings::IRQF_IRQPOLL as u64);
+
+/// Interrupt is not reenabled after the hardirq handler finished. Used by
+/// threaded interrupts which need to keep the irq line disabled until the
+/// threaded handler has been run.
+pub const ONESHOT: Flags = Flags(bindings::IRQF_ONESHOT as u64);
+
+/// Do not disable this IRQ during suspend. Does not guarantee that this
+/// interrupt will wake the system from a suspended state.
+pub const NO_SUSPEND: Flags = Flags(bindings::IRQF_NO_SUSPEND as u64);
+
+/// Force enable it on resume even if [`NO_SUSPEND`] is set.
+pub const FORCE_RESUME: Flags = Flags(bindings::IRQF_FORCE_RESUME as u64);
+
+/// Interrupt cannot be threaded.
+pub const NO_THREAD: Flags = Flags(bindings::IRQF_NO_THREAD as u64);
+
+/// Resume IRQ early during syscore instead of at device resume time.
+pub const EARLY_RESUME: Flags = Flags(bindings::IRQF_EARLY_RESUME as u64);
+
+/// If the IRQ is shared with a [`NO_SUSPEND`] user, execute this interrupt
+/// handler after suspending interrupts. For system wakeup devices users
+/// need to implement wakeup detection in their interrupt handlers.
+pub const COND_SUSPEND: Flags = Flags(bindings::IRQF_COND_SUSPEND as u64);
+
+/// Don't enable IRQ or NMI automatically when users request it. Users will
+/// enable it explicitly by `enable_irq` or `enable_nmi` later.
+pub const NO_AUTOEN: Flags = Flags(bindings::IRQF_NO_AUTOEN as u64);
+
+/// Exclude from runnaway detection for IPI and similar handlers, depends on
+/// `PERCPU`.
+pub const NO_DEBUG: Flags = Flags(bindings::IRQF_NO_DEBUG as u64);

-- 
2.49.0