From: Valentin Schneider <valentin.schneider@arm.com>
To: Marc Zyngier <maz@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, Will Deacon <will@kernel.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Russell King <linux@arm.linux.org.uk>,
Thomas Gleixner <tglx@linutronix.de>,
Jason Cooper <jason@lakedaemon.net>,
Sumit Garg <sumit.garg@linaro.org>,
kernel-team@android.com
Subject: Re: [PATCH 01/11] genirq: Add fasteoi IPI flow
Date: Tue, 19 May 2020 23:25:43 +0100 [thread overview]
Message-ID: <jhj8shnr28o.mognet@arm.com> (raw)
In-Reply-To: <20200519161755.209565-2-maz@kernel.org>
On 19/05/20 17:17, Marc Zyngier wrote:
> For irqchips using the fasteoi flow, IPIs are a bit special.
>
> They need to be EOId early (before calling the handler), as
> funny things may happen in the handler (they do not necessarily
> behave like a normal interrupt), and that the arch code is
> already handling the stats.
>
> Signed-off-by: Marc Zyngier <maz@kernel.org>
> ---
> include/linux/irq.h | 1 +
> kernel/irq/chip.c | 26 ++++++++++++++++++++++++++
> 2 files changed, 27 insertions(+)
>
> diff --git a/include/linux/irq.h b/include/linux/irq.h
> index 8d5bc2c237d7..726f94d8b8cc 100644
> --- a/include/linux/irq.h
> +++ b/include/linux/irq.h
> @@ -621,6 +621,7 @@ static inline int irq_set_parent(int irq, int parent_irq)
> */
> extern void handle_level_irq(struct irq_desc *desc);
> extern void handle_fasteoi_irq(struct irq_desc *desc);
> +extern void handle_percpu_devid_fasteoi_ipi(struct irq_desc *desc);
> extern void handle_edge_irq(struct irq_desc *desc);
> extern void handle_edge_eoi_irq(struct irq_desc *desc);
> extern void handle_simple_irq(struct irq_desc *desc);
> diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
> index 41e7e37a0928..7b0b789cfed4 100644
> --- a/kernel/irq/chip.c
> +++ b/kernel/irq/chip.c
> @@ -955,6 +955,32 @@ void handle_percpu_devid_irq(struct irq_desc *desc)
> chip->irq_eoi(&desc->irq_data);
> }
>
> +/**
> + * handle_percpu_devid_fasteoi_ipi - Per CPU local IPI handler with per cpu
> + * dev ids
> + * @desc: the interrupt description structure for this irq
> + *
> + * The biggest differences with the IRQ version are that:
> + * - the interrupt is EOIed early, as the IPI could result in a context
> + * switch, and we need to make sure the IPI can fire again
> + * - Stats are usually handled at the architecture level, so we ignore them
> + * here
> + */
> +void handle_percpu_devid_fasteoi_ipi(struct irq_desc *desc)
> +{
> + struct irq_chip *chip = irq_desc_get_chip(desc);
> + struct irqaction *action = desc->action;
> + unsigned int irq = irq_desc_get_irq(desc);
> + irqreturn_t res;
> +
Tied to the following patch, does that want something like
+ if (!irq_settings_is_no_accounting(desc))
+ __kstat_incr_irqs_this_cpu(desc);
+
While I'm at it, now that we would have IPIs as 'normal' interrupts, what
prevents us from getting rid of the arch-side accounting? Is it just that
we are keeping it as long as handle_IPI() lives, or are there more hurdles
hidden around?
> + if (chip->irq_eoi)
> + chip->irq_eoi(&desc->irq_data);
> +
> + trace_irq_handler_entry(irq, action);
> + res = action->handler(irq, raw_cpu_ptr(action->percpu_dev_id));
> + trace_irq_handler_exit(irq, action, res);
> +}
> +
> /**
> * handle_percpu_devid_fasteoi_nmi - Per CPU local NMI handler with per cpu
> * dev ids
next prev parent reply other threads:[~2020-05-19 22:25 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-19 16:17 [PATCH 00/11] arm/arm64: Turning IPIs into normal interrupts Marc Zyngier
2020-05-19 16:17 ` [PATCH 01/11] genirq: Add fasteoi IPI flow Marc Zyngier
2020-05-19 19:47 ` Florian Fainelli
2020-06-12 9:54 ` Marc Zyngier
2020-05-19 22:25 ` Valentin Schneider [this message]
2020-05-19 22:29 ` Valentin Schneider
2020-06-12 9:58 ` Marc Zyngier
2020-05-19 16:17 ` [PATCH 02/11] genirq: Allow interrupts to be excluded from /proc/interrupts Marc Zyngier
2020-05-19 16:17 ` [PATCH 03/11] arm64: Allow IPIs to be handled as normal interrupts Marc Zyngier
2020-05-21 14:03 ` Valentin Schneider
2020-05-19 16:17 ` [PATCH 04/11] ARM: " Marc Zyngier
2020-05-19 22:24 ` Russell King - ARM Linux admin
2020-05-21 14:03 ` Valentin Schneider
2020-05-21 15:12 ` Russell King - ARM Linux admin
2020-05-21 16:11 ` Valentin Schneider
2020-05-19 16:17 ` [PATCH 05/11] irqchip/gic-v3: Describe the SGI range Marc Zyngier
2020-05-19 16:17 ` [PATCH 06/11] irqchip/gic-v3: Configure SGIs as standard interrupts Marc Zyngier
2020-05-20 9:52 ` Sumit Garg
2020-05-20 10:24 ` Marc Zyngier
2020-05-21 14:04 ` Valentin Schneider
2020-06-12 10:39 ` Marc Zyngier
2020-05-19 16:17 ` [PATCH 07/11] irqchip/gic: Refactor SMP configuration Marc Zyngier
2020-05-19 16:17 ` [PATCH 08/11] irqchip/gic: Configure SGIs as standard interrupts Marc Zyngier
2021-04-20 20:37 ` dann frazier
2021-04-20 21:25 ` dann frazier
2021-04-21 10:58 ` Marc Zyngier
2021-04-21 14:52 ` dann frazier
2021-04-21 15:49 ` Marc Zyngier
2020-05-19 16:17 ` [PATCH 09/11] irqchip/gic-common: Don't enable SGIs by default Marc Zyngier
2020-05-19 16:17 ` [PATCH 10/11] irqchip/bcm2836: Configure mailbox interrupts as standard interrupts Marc Zyngier
2020-05-19 16:17 ` [PATCH 11/11] arm64: Kill __smp_cross_call and co Marc Zyngier
2020-05-19 17:50 ` [PATCH 00/11] arm/arm64: Turning IPIs into normal interrupts Florian Fainelli
2020-05-19 19:47 ` Florian Fainelli
2020-06-12 9:49 ` Marc Zyngier
2020-06-12 16:57 ` Florian Fainelli
2020-05-19 22:25 ` Valentin Schneider
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=jhj8shnr28o.mognet@arm.com \
--to=valentin.schneider@arm.com \
--cc=catalin.marinas@arm.com \
--cc=jason@lakedaemon.net \
--cc=kernel-team@android.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux@arm.linux.org.uk \
--cc=maz@kernel.org \
--cc=sumit.garg@linaro.org \
--cc=tglx@linutronix.de \
--cc=will@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).