From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D0EBB28C2D1; Fri, 15 Aug 2025 12:07:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755259667; cv=none; b=psYuKKAzQRDWkw5M+r1ck7V7qQ2tXe1n/uEmyJy5A64y/037v7s5p+h4bGbUXcXZouXiY5x+uJFs//5hnIbe38/XhTkRsp91oWUr/qqdzmHfx5ky1N/AqwyJojWvHJ9cWCE4t+vxiy6a/Tj/SE1pcjJNtnl6rruRMR96ZkFGrvs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755259667; c=relaxed/simple; bh=+zK6FWDvXXZlff+02xUXRsfbnd6zM/7GQBlYSioRBcU=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=NV5L1vRhEfl/AiC7/JiWmW65+fczbMDgRPEz8IxSSfzlWJ2J1jBfXZI+qte9x+AE3irdhMVfIrqfe08GdkIQZH7x3RS0tfNefkiQVDuC4dDcAklOqhiX/eQWny1EWt3wK0KBD4xoEhujtks/Ot8R0LrGetwrVwF7t7K9YIQ/4Ec= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=bYw4H6xW; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="bYw4H6xW" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9CF91C4CEEB; Fri, 15 Aug 2025 12:07:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1755259667; bh=+zK6FWDvXXZlff+02xUXRsfbnd6zM/7GQBlYSioRBcU=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=bYw4H6xWsoJO4pHYknubTtwVz1nXe5VvLf/vem/wB9vql1uVcLjbvYMyHhxJ1Se5a VXHAs9wT6Cl8rpaESkwaNKoySvsH60j8iW5kGOHG7Y9FHtt40GXqFHCX0KjeVK06tM Wj2UPX3h+uSGlLkrDMLEWRMZNRDLoxw3tOpI1Jwqnn1atxjkY5DXIbU/Lr3dhTlNTP nF/xx87bWyZTOELLA99uNgtAMhyQchaGtit1ouBts7HrLCBLQXuzjeu1BSSC0CPbff VluuhMv6rt9QQmGm5EvCqtSSeLeom/fGKxx282V5s8QFUshnlJlNENf1s6CToNyziU MAsGVBHGBYkOA== From: Andreas Hindborg To: Daniel Almeida , Miguel Ojeda , Alex Gaynor , Boqun Feng , Gary Guo , =?utf-8?Q?Bj=C3=B6rn?= Roy Baron , Alice Ryhl , Trevor Gross , Danilo Krummrich , Greg Kroah-Hartman , "Rafael J. Wysocki" , Thomas Gleixner , Bjorn Helgaas , Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= , Benno Lossin Cc: linux-kernel@vger.kernel.org, rust-for-linux@vger.kernel.org, linux-pci@vger.kernel.org, Joel Fernandes , Dirk Behme , Daniel Almeida Subject: Re: [PATCH v9 2/7] rust: irq: add flags module In-Reply-To: <20250811-topics-tyr-request_irq2-v9-2-0485dcd9bcbf@collabora.com> References: <20250811-topics-tyr-request_irq2-v9-0-0485dcd9bcbf@collabora.com> <20250811-topics-tyr-request_irq2-v9-2-0485dcd9bcbf@collabora.com> Date: Fri, 15 Aug 2025 14:02:36 +0200 Message-ID: <87349seqsj.fsf@t14s.mail-host-address-is-not-set> Precedence: bulk X-Mailing-List: rust-for-linux@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain "Daniel Almeida" writes: > 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. > > Reviewed-by: Alice Ryhl > Tested-by: Joel Fernandes > Tested-by: Dirk Behme > Signed-off-by: Daniel Almeida > --- > rust/kernel/irq.rs | 5 ++ > rust/kernel/irq/flags.rs | 124 +++++++++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 129 insertions(+) > > diff --git a/rust/kernel/irq.rs b/rust/kernel/irq.rs > index fae7b15effc80c936d6bffbd5b4150000d6c2898..068df2fea31de51115c30344f7ebdb4da4ad86cc 100644 > --- a/rust/kernel/irq.rs > +++ b/rust/kernel/irq.rs > @@ -9,3 +9,8 @@ > //! 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. > +mod flags; > + > +pub use flags::Flags; > diff --git a/rust/kernel/irq/flags.rs b/rust/kernel/irq/flags.rs > new file mode 100644 > index 0000000000000000000000000000000000000000..e62820ea67755123b4f96e4331244bbb4fbcfd9d > --- /dev/null > +++ b/rust/kernel/irq/flags.rs > @@ -0,0 +1,124 @@ > +// SPDX-License-Identifier: GPL-2.0 > +// SPDX-FileCopyrightText: Copyright 2025 Collabora ltd. > + > +use crate::bindings; > +use crate::prelude::*; > + > +/// Flags to be used when registering IRQ handlers. > +/// > +/// Flags can be used to request specific behaviors when registering an IRQ > +/// handler, and can be combined using the `|`, `&`, and `!` operators to > +/// further control the system's behavior. > +/// > +/// A common use case is to register a shared interrupt, as sharing the line > +/// between devices is increasingly common in modern systems and is even > +/// required for some buses. This requires setting [`Flags::SHARED`] when > +/// requesting the interrupt. Other use cases include setting the trigger type > +/// through `Flags::TRIGGER_*`, which determines when the interrupt fires, or > +/// controlling whether the interrupt is masked after the handler runs by using > +/// [`Flags::ONESHOT`]. > +/// > +/// If an invalid combination of flags is provided, the system will refuse to > +/// register the handler, and lower layers will enforce certain flags when > +/// necessary. This means, for example, that all the > +/// [`crate::irq::Registration`] for a shared interrupt have to agree on `rustdoc` will complain about this being undefined. > +/// [`Flags::SHARED`] and on the same trigger type, if set. > +#[derive(Clone, Copy, PartialEq, Eq)] > +pub struct Flags(c_ulong); > + > +impl Flags { > + /// Use the interrupt line as already configured. > + pub const TRIGGER_NONE: Flags = Flags::new(bindings::IRQF_TRIGGER_NONE); > + > + /// The interrupt is triggered when the signal goes from low to high. > + pub const TRIGGER_RISING: Flags = Flags::new(bindings::IRQF_TRIGGER_RISING); > + > + /// The interrupt is triggered when the signal goes from high to low. > + pub const TRIGGER_FALLING: Flags = Flags::new(bindings::IRQF_TRIGGER_FALLING); > + > + /// The interrupt is triggered while the signal is held high. > + pub const TRIGGER_HIGH: Flags = Flags::new(bindings::IRQF_TRIGGER_HIGH); > + > + /// The interrupt is triggered while the signal is held low. > + pub const TRIGGER_LOW: Flags = Flags::new(bindings::IRQF_TRIGGER_LOW); > + > + /// Allow sharing the IRQ among several devices. > + pub const SHARED: Flags = Flags::new(bindings::IRQF_SHARED); > + > + /// Set by callers when they expect sharing mismatches to occur. > + pub const PROBE_SHARED: Flags = Flags::new(bindings::IRQF_PROBE_SHARED); > + > + /// Flag to mark this interrupt as timer interrupt. > + pub const TIMER: Flags = Flags::new(bindings::IRQF_TIMER); > + > + /// Interrupt is per CPU. > + pub const PERCPU: Flags = Flags::new(bindings::IRQF_PERCPU); > + > + /// Flag to exclude this interrupt from irq balancing. > + pub const NOBALANCING: Flags = Flags::new(bindings::IRQF_NOBALANCING); > + > + /// 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::new(bindings::IRQF_IRQPOLL); > + > + /// 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::new(bindings::IRQF_ONESHOT); > + > + /// 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::new(bindings::IRQF_NO_SUSPEND); > + > + /// Force enable it on resume even if [`Flags::NO_SUSPEND`] is set. > + pub const FORCE_RESUME: Flags = Flags::new(bindings::IRQF_FORCE_RESUME); > + > + /// Interrupt cannot be threaded. > + pub const NO_THREAD: Flags = Flags::new(bindings::IRQF_NO_THREAD); > + > + /// Resume IRQ early during syscore instead of at device resume time. > + pub const EARLY_RESUME: Flags = Flags::new(bindings::IRQF_EARLY_RESUME); > + > + /// If the IRQ is shared with a [`Flags::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::new(bindings::IRQF_COND_SUSPEND); > + > + /// 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::new(bindings::IRQF_NO_AUTOEN); > + > + /// Exclude from runnaway detection for IPI and similar handlers, depends on > + /// `PERCPU`. Should we link `PERCPU` here? > + pub const NO_DEBUG: Flags = Flags::new(bindings::IRQF_NO_DEBUG); > + > + pub(crate) fn into_inner(self) -> c_ulong { You need `#[expect(dead_code)]` here. > + self.0 > + } > + > + const fn new(value: u32) -> Self { > + build_assert!(value as u64 <= c_ulong::MAX as u64); I am curious about this line. Can you add a short explanation? I would think this can never assert. That would require c_ulong to be less than 32 bits, right? Are there any configurations where that is the case? Best regards, Andreas Hindborg