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From: "Farber, Eliav" <farbere@amazon.com>
To: Thomas Gleixner <tglx@linutronix.de>,
	"linux@armlinux.org.uk" <linux@armlinux.org.uk>,
	"catalin.marinas@arm.com" <catalin.marinas@arm.com>,
	"will@kernel.org" <will@kernel.org>,
	"mpe@ellerman.id.au" <mpe@ellerman.id.au>,
	"npiggin@gmail.com" <npiggin@gmail.com>,
	"christophe.leroy@csgroup.eu" <christophe.leroy@csgroup.eu>,
	"naveen@kernel.org" <naveen@kernel.org>,
	"maddy@linux.ibm.com" <maddy@linux.ibm.com>,
	"paul.walmsley@sifive.com" <paul.walmsley@sifive.com>,
	"palmer@dabbelt.com" <palmer@dabbelt.com>,
	"aou@eecs.berkeley.edu" <aou@eecs.berkeley.edu>,
	"akpm@linux-foundation.org" <akpm@linux-foundation.org>,
	"bhe@redhat.com" <bhe@redhat.com>,
	"hbathini@linux.ibm.com" <hbathini@linux.ibm.com>,
	"adityag@linux.ibm.com" <adityag@linux.ibm.com>,
	"songshuaishuai@tinylab.org" <songshuaishuai@tinylab.org>,
	"takakura@valinux.co.jp" <takakura@valinux.co.jp>,
	"linux-arm-kernel@lists.infradead.org"
	<linux-arm-kernel@lists.infradead.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>,
	"linux-riscv@lists.infradead.org"
	<linux-riscv@lists.infradead.org>
Cc: "Chocron, Jonathan" <jonnyc@amazon.com>
Subject: RE: [PATCH v2] arm64: kexec: Check if IRQ is already masked before masking
Date: Thu, 28 Nov 2024 20:07:57 +0000	[thread overview]
Message-ID: <3a499ecdfa5042f8b6e8834c47cdb2d9@amazon.com> (raw)

On 11/28/2024 12:39 PM, Thomas Gleixner wrote:
> This is just wrong. If the interrupt was torn down, then its state is deactivated and it was masked already. So the EOI handling and the mask/disable dance are neither required nor make sense.
>
> So this whole thing should be:
>
>                 chip = irq_desc_get_chip(desc);
> -               if (!chip)
> +               if (!chip || !irqd_is_started(&desc->irq_data))
>                         continue;
ACK. Will be done this way in V3.

> But what's worse is that we have 4 almost identical variants of the same code.
>
> So instead of exposing core functionality and "fixing" up four variants, can we please have a consolidated version of this function in the core
> code:
>                 struct irq_chip *chip;
>                 int check_eoi = 1;
>
>                 chip = irq_desc_get_chip(desc);
>                 if (!chip || !irqd_is_started(&desc->irq_data))
>                         continue;
>
>                 if (IS_ENABLED(CONFIG_.....)) {
>                         /*
>                          * Add a sensible comment which explains this.
>                          */
>                         check_eoi = irq_set_irqchip_state(....);
>                 }
>
>                 if (check_eoi && ....)
>                         chip->irq_eoi(&desc->irq_data);
>
>                 irq_shutdown(desc);
>
> No?
In V3 I will add a preliminary patch that will remove the four variants
and instead add a common implementations to the kexec core.

Thanks, Eliav

_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv

WARNING: multiple messages have this Message-ID (diff)
From: "Farber, Eliav" <farbere@amazon.com>
To: Thomas Gleixner <tglx@linutronix.de>,
	"linux@armlinux.org.uk" <linux@armlinux.org.uk>,
	"catalin.marinas@arm.com" <catalin.marinas@arm.com>,
	"will@kernel.org" <will@kernel.org>,
	"mpe@ellerman.id.au" <mpe@ellerman.id.au>,
	"npiggin@gmail.com" <npiggin@gmail.com>,
	"christophe.leroy@csgroup.eu" <christophe.leroy@csgroup.eu>,
	"naveen@kernel.org" <naveen@kernel.org>,
	"maddy@linux.ibm.com" <maddy@linux.ibm.com>,
	"paul.walmsley@sifive.com" <paul.walmsley@sifive.com>,
	"palmer@dabbelt.com" <palmer@dabbelt.com>,
	"aou@eecs.berkeley.edu" <aou@eecs.berkeley.edu>,
	"akpm@linux-foundation.org" <akpm@linux-foundation.org>,
	"bhe@redhat.com" <bhe@redhat.com>,
	"hbathini@linux.ibm.com" <hbathini@linux.ibm.com>,
	"adityag@linux.ibm.com" <adityag@linux.ibm.com>,
	"songshuaishuai@tinylab.org" <songshuaishuai@tinylab.org>,
	"takakura@valinux.co.jp" <takakura@valinux.co.jp>,
	"linux-arm-kernel@lists.infradead.org"
	<linux-arm-kernel@lists.infradead.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>,
	"linux-riscv@lists.infradead.org"
	<linux-riscv@lists.infradead.org>
Cc: "Chocron, Jonathan" <jonnyc@amazon.com>
Subject: RE: [PATCH v2] arm64: kexec: Check if IRQ is already masked before masking
Date: Thu, 28 Nov 2024 20:07:57 +0000	[thread overview]
Message-ID: <3a499ecdfa5042f8b6e8834c47cdb2d9@amazon.com> (raw)

On 11/28/2024 12:39 PM, Thomas Gleixner wrote:
> This is just wrong. If the interrupt was torn down, then its state is deactivated and it was masked already. So the EOI handling and the mask/disable dance are neither required nor make sense.
>
> So this whole thing should be:
>
>                 chip = irq_desc_get_chip(desc);
> -               if (!chip)
> +               if (!chip || !irqd_is_started(&desc->irq_data))
>                         continue;
ACK. Will be done this way in V3.

> But what's worse is that we have 4 almost identical variants of the same code.
>
> So instead of exposing core functionality and "fixing" up four variants, can we please have a consolidated version of this function in the core
> code:
>                 struct irq_chip *chip;
>                 int check_eoi = 1;
>
>                 chip = irq_desc_get_chip(desc);
>                 if (!chip || !irqd_is_started(&desc->irq_data))
>                         continue;
>
>                 if (IS_ENABLED(CONFIG_.....)) {
>                         /*
>                          * Add a sensible comment which explains this.
>                          */
>                         check_eoi = irq_set_irqchip_state(....);
>                 }
>
>                 if (check_eoi && ....)
>                         chip->irq_eoi(&desc->irq_data);
>
>                 irq_shutdown(desc);
>
> No?
In V3 I will add a preliminary patch that will remove the four variants
and instead add a common implementations to the kexec core.

Thanks, Eliav


             reply	other threads:[~2024-12-02 17:07 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-11-28 20:07 Farber, Eliav [this message]
2024-11-28 20:07 ` [PATCH v2] arm64: kexec: Check if IRQ is already masked before masking Farber, Eliav
  -- strict thread matches above, loose matches on Subject: below --
2024-11-27 15:22 Eliav Farber
2024-11-27 15:22 ` Eliav Farber
2024-11-28 10:39 ` Thomas Gleixner
2024-11-28 10:39   ` Thomas Gleixner
2024-11-28 10:43 ` Thomas Gleixner
2024-11-28 10:43   ` Thomas Gleixner

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