From: Jonathan Cameron <jonathan.cameron@huawei.com>
To: Marc Zyngier <maz@kernel.org>
Cc: <linux-kernel@vger.kernel.org>,
<linux-arm-kernel@lists.infradead.org>,
<linux-acpi@vger.kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
"Mark Rutland" <mark.rutland@arm.com>,
Will Deacon <will@kernel.org>,
"Rafael J. Wysocki" <rafael@kernel.org>,
Rob Herring <robh@kernel.org>,
"Saravana Kannan" <saravanak@google.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Sven Peter <sven@kernel.org>, Janne Grunau <j@jannau.net>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
James Clark <james.clark@linaro.org>,
Jinjie Ruan <ruanjinjie@huawei.com>,
"Alexandru Elisei" <alexandru.elisei@arm.com>
Subject: Re: [PATCH v4 16/26] genirq: Allow per-cpu interrupt sharing for non-overlapping affinities
Date: Wed, 12 Nov 2025 18:25:21 +0000 [thread overview]
Message-ID: <20251112182521.000027ad@huawei.com> (raw)
In-Reply-To: <20251020122944.3074811-17-maz@kernel.org>
On Mon, 20 Oct 2025 13:29:33 +0100
Marc Zyngier <maz@kernel.org> wrote:
> Interrupt sharing for percpu-devid interrupts is forbidden, and
> for good reasons. These are interrupts generated *from* a CPU and
> handled by itself (timer, for example). Nobody in their right mind
> would put two devices on the same pin (and if they have, they get to
> keep the pieces...).
>
> But this also prevents more benign cases, where devices are connected
> to groups of CPUs, and for which the affinities are not overlapping.
> Effectively, the only thing they share is the interrupt number, and
> nothing else.
>
> Let's tweak the definition of IRQF_SHARED applied to percpu_devid
> interrupts to allow this particular case. This results in extra
> validation at the point of the interrupt being setup and freed,
> as well as a tiny bit of extra complexity for interrupts at handling
> time (to pick the correct irqaction).
>
> Tested-by: Will Deacon <will@kernel.org>
> Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
next prev parent reply other threads:[~2025-11-12 18:25 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-10-20 12:29 [PATCH v4 00/26] genirq: Add support for percpu_devid IRQ affinity Marc Zyngier
2025-10-20 12:29 ` [PATCH v4 01/26] irqdomain: Add firmware info reporting interface Marc Zyngier
2025-10-20 12:29 ` [PATCH v4 02/26] ACPI: irq: Add IRQ affinity " Marc Zyngier
2025-10-20 12:29 ` [PATCH v4 03/26] of/irq: " Marc Zyngier
2025-10-20 12:29 ` [PATCH v4 04/26] platform: Add firmware-agnostic irq and affinity retrieval interface Marc Zyngier
2025-10-20 12:29 ` [PATCH v4 05/26] irqchip/gic-v3: Add FW info retrieval support Marc Zyngier
2025-11-12 16:54 ` Jonathan Cameron
2025-10-20 12:29 ` [PATCH v4 06/26] irqchip/apple-aic: " Marc Zyngier
2025-10-20 12:29 ` [PATCH v4 07/26] coresight: trbe: Convert to new IRQ affinity retrieval API Marc Zyngier
2025-11-12 16:58 ` Jonathan Cameron
2025-10-20 12:29 ` [PATCH v4 08/26] perf: arm_pmu: " Marc Zyngier
2025-11-12 16:59 ` Jonathan Cameron
2025-10-20 12:29 ` [PATCH v4 09/26] perf: arm_spe_pmu: " Marc Zyngier
2025-11-12 17:58 ` Jonathan Cameron
2025-10-20 12:29 ` [PATCH v4 10/26] irqchip/gic-v3: Switch high priority PPIs over to handle_percpu_devid_irq() Marc Zyngier
2025-11-12 18:06 ` Jonathan Cameron
2025-10-20 12:29 ` [PATCH v4 11/26] genirq: Kill handle_percpu_devid_fasteoi_nmi() Marc Zyngier
2025-11-12 18:07 ` Jonathan Cameron
2025-10-20 12:29 ` [PATCH v4 12/26] genirq: Merge irqaction::{dev_id,percpu_dev_id} Marc Zyngier
2025-11-12 18:09 ` Jonathan Cameron
2025-10-20 12:29 ` [PATCH v4 13/26] genirq: Factor-in percpu irqaction creation Marc Zyngier
2025-10-20 12:29 ` [PATCH v4 14/26] genirq: Add affinity to percpu_devid interrupt requests Marc Zyngier
2025-11-12 18:13 ` Jonathan Cameron
2025-11-13 13:37 ` Marc Zyngier
2025-10-20 12:29 ` [PATCH v4 15/26] genirq: Update request_percpu_nmi() to take an affinity Marc Zyngier
2025-11-12 18:15 ` Jonathan Cameron
2025-10-20 12:29 ` [PATCH v4 16/26] genirq: Allow per-cpu interrupt sharing for non-overlapping affinities Marc Zyngier
2025-11-12 18:25 ` Jonathan Cameron [this message]
2025-12-04 10:56 ` Daniel Thompson
2025-12-04 14:21 ` Marc Zyngier
2025-12-05 9:19 ` Daniel Thompson
2025-10-20 12:29 ` [PATCH v4 17/26] genirq: Add request_percpu_irq_affinity() helper Marc Zyngier
2025-11-12 18:27 ` Jonathan Cameron
2025-11-13 13:39 ` Marc Zyngier
2025-10-20 12:29 ` [PATCH v4 18/26] perf: arm_pmu: Request specific affinities for percpu NMI/IRQ Marc Zyngier
2025-11-12 18:31 ` Jonathan Cameron
2025-10-20 12:29 ` [PATCH v4 19/26] perf: arm_spe_pmu: Request specific affinities for percpu IRQ Marc Zyngier
2025-11-12 18:31 ` Jonathan Cameron
2025-10-20 12:29 ` [PATCH v4 20/26] coresight: trbe: " Marc Zyngier
2025-11-12 18:32 ` Jonathan Cameron
2025-10-20 12:29 ` [PATCH v4 21/26] irqchip/gic-v3: Drop support for custom PPI partitions Marc Zyngier
2025-10-20 12:29 ` [PATCH v4 22/26] irqchip/apple-aic: Drop support for custom PMU irq partitions Marc Zyngier
2025-10-20 12:29 ` [PATCH v4 23/26] irqchip: Kill irq-partition-percpu Marc Zyngier
2025-10-20 12:29 ` [PATCH v4 24/26] genirq: Kill irq_{g,s}et_percpu_devid_partition() Marc Zyngier
2025-10-20 12:29 ` [PATCH v4 25/26] irqdomain: Kill of_node_to_fwnode() helper Marc Zyngier
2025-11-12 18:35 ` Jonathan Cameron
2025-10-20 12:29 ` [PATCH v4 26/26] perf: arm_pmu: Kill last use of per-CPU cpu_armpmu pointer Marc Zyngier
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