Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
MIME-Version: 1.0
References: <20211021180236.37428-1-mark.rutland@arm.com> <20211021180236.37428-8-mark.rutland@arm.com>
In-Reply-To: <20211021180236.37428-8-mark.rutland@arm.com>
From:   Greentime Hu <green.hu@gmail.com>
Date:   Fri, 22 Oct 2021 14:35:05 +0800
Message-ID: <CAEbi=3cXRuXzViYODk_pHjCBkNSiYZBqB0TO5pFEAfGcPanVug@mail.gmail.com>
Subject: Re: [PATCH 07/15] irq: nds32: avoid CONFIG_HANDLE_DOMAIN_IRQ
To:     Mark Rutland <mark.rutland@arm.com>
Cc:     Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Albert Ou <aou@eecs.berkeley.edu>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Vincent Chen <deanbo422@gmail.com>,
        Guo Ren <guoren@kernel.org>, Jonas Bonn <jonas@southpole.se>,
        kernelfans@gmail.com, linux-arm-kernel@lists.infradead.org,
        Russell King <linux@armlinux.org.uk>, maz@kernel.org,
        Nickhu <nickhu@andestech.com>,
        Palmer Dabbelt <palmer@dabbelt.com>, paulmck@kernel.org,
        Paul Walmsley <paul.walmsley@sifive.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Stafford Horne <shorne@gmail.com>,
        Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>,
        Thomas Gleixner <tglx@linutronix.de>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
        vgupta@kernel.org, Will Deacon <will@kernel.org>,
        Alan Kao <alankao@andestech.com>,
        =?UTF-8?B?Sy5DLiBLdWVuLUNoZXJuIExpbijmnpflnaTmiJAp?= 
        <kclin@andestech.com>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Precedence: bulk

Mark Rutland <mark.rutland@arm.com> =E6=96=BC 2021=E5=B9=B410=E6=9C=8822=E6=
=97=A5 =E9=80=B1=E4=BA=94 =E4=B8=8A=E5=8D=882:03=E5=AF=AB=E9=81=93=EF=BC=9A
>
> In preparation for removing HANDLE_DOMAIN_IRQ, have arch/nds32 perform
> all the necessary IRQ entry accounting in its entry code.
>
> Currently arch/nds32 is tightly coupled with the ativic32 irqchip, and
> while the entry code should logically live under arch/nds32/, moving the
> entry logic there makes things more convoluted. So for now, place the
> entry logic in the ativic32 irqchip, but separated into a separate
> function to make the split of responsibility clear.
>
> In future this should probably use GENERIC_IRQ_MULTI_HANDLER to cleanly
> decouple this.
>
> There should be no functional change as a result of this patch.
>
> Signed-off-by: Mark Rutland <mark.rutland@arm.com>
> Cc: Greentime Hu <green.hu@gmail.com>
> Cc: Marc Zyngier <maz@kernel.org>
> Cc: Nick Hu <nickhu@andestech.com>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Vincent Chen <deanbo422@gmail.com>
> ---
>  arch/nds32/Kconfig             |  1 -
>  drivers/irqchip/irq-ativic32.c | 22 ++++++++++++++++++++--
>  2 files changed, 20 insertions(+), 3 deletions(-)
>
> diff --git a/arch/nds32/Kconfig b/arch/nds32/Kconfig
> index aea26e739543..4d1421b18734 100644
> --- a/arch/nds32/Kconfig
> +++ b/arch/nds32/Kconfig
> @@ -27,7 +27,6 @@ config NDS32
>         select GENERIC_LIB_MULDI3
>         select GENERIC_LIB_UCMPDI2
>         select GENERIC_TIME_VSYSCALL
> -       select HANDLE_DOMAIN_IRQ
>         select HAVE_ARCH_TRACEHOOK
>         select HAVE_DEBUG_KMEMLEAK
>         select HAVE_EXIT_THREAD
> diff --git a/drivers/irqchip/irq-ativic32.c b/drivers/irqchip/irq-ativic3=
2.c
> index 476d6024aaf2..223dd2f97d28 100644
> --- a/drivers/irqchip/irq-ativic32.c
> +++ b/drivers/irqchip/irq-ativic32.c
> @@ -5,11 +5,14 @@
>  #include <linux/of.h>
>  #include <linux/of_irq.h>
>  #include <linux/of_address.h>
> +#include <linux/hardirq.h>
>  #include <linux/interrupt.h>
>  #include <linux/irqdomain.h>
>  #include <linux/irqchip.h>
>  #include <nds32_intrinsic.h>
>
> +#include <asm/irq_regs.h>
> +
>  unsigned long wake_mask;
>
>  static void ativic32_ack_irq(struct irq_data *data)
> @@ -103,10 +106,25 @@ static irq_hw_number_t get_intr_src(void)
>                 - NDS32_VECTOR_offINTERRUPT;
>  }
>
> -asmlinkage void asm_do_IRQ(struct pt_regs *regs)
> +static void ativic32_handle_irq(struct pt_regs *regs)
>  {
>         irq_hw_number_t hwirq =3D get_intr_src();
> -       handle_domain_irq(root_domain, hwirq, regs);
> +       generic_handle_domain_irq(root_domain, hwirq);
> +}
> +
> +/*
> + * TODO: convert nds32 to GENERIC_IRQ_MULTI_HANDLER so that this entry l=
ogic
> + * can live in arch code.
> + */
> +asmlinkage void asm_do_IRQ(struct pt_regs *regs)
> +{
> +       struct pt_regs *old_regs;
> +
> +       irq_enter();
> +       old_regs =3D set_irq_regs(regs);
> +       ativic32_handle_irq(regs);
> +       set_irq_regs(old_regs);
> +       irq_exit();
>  }
>
>  int __init ativic32_init_irq(struct device_node *node, struct device_nod=
e *parent)
> --
> 2.11.0
>

Loop in Alan and KC.