From: Charlie Jenkins <charlie@rivosinc.com>
To: Xu Lu <luxu.kernel@bytedance.com>
Cc: anup@brainfault.org, tglx@linutronix.de,
paul.walmsley@sifive.com, palmer@dabbelt.com,
lihangjing@bytedance.com, xieyongji@bytedance.com,
linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] irqchip: riscv: Order normal writes and IPI writes
Date: Thu, 16 Jan 2025 13:09:18 -0800 [thread overview]
Message-ID: <Z4l1fklnUPyTSLO4@ghost> (raw)
In-Reply-To: <20250116120710.51673-1-luxu.kernel@bytedance.com>
On Thu, Jan 16, 2025 at 08:07:10PM +0800, Xu Lu wrote:
> Replace writel_relaxed() with writel() when issuing IPI to ensure all
> previous write operations made by current CPU are visible to other CPUs.
Did you experience an ordering issue from this?
- Charlie
>
> Signed-off-by: Xu Lu <luxu.kernel@bytedance.com>
> ---
> drivers/irqchip/irq-riscv-imsic-early.c | 2 +-
> drivers/irqchip/irq-thead-c900-aclint-sswi.c | 2 +-
> 2 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/irqchip/irq-riscv-imsic-early.c b/drivers/irqchip/irq-riscv-imsic-early.c
> index c5c2e6929a2f..275df5005705 100644
> --- a/drivers/irqchip/irq-riscv-imsic-early.c
> +++ b/drivers/irqchip/irq-riscv-imsic-early.c
> @@ -27,7 +27,7 @@ static void imsic_ipi_send(unsigned int cpu)
> {
> struct imsic_local_config *local = per_cpu_ptr(imsic->global.local, cpu);
>
> - writel_relaxed(IMSIC_IPI_ID, local->msi_va);
> + writel(IMSIC_IPI_ID, local->msi_va);
> }
>
> static void imsic_ipi_starting_cpu(void)
> diff --git a/drivers/irqchip/irq-thead-c900-aclint-sswi.c b/drivers/irqchip/irq-thead-c900-aclint-sswi.c
> index b0e366ade427..8ff6e7a1363b 100644
> --- a/drivers/irqchip/irq-thead-c900-aclint-sswi.c
> +++ b/drivers/irqchip/irq-thead-c900-aclint-sswi.c
> @@ -31,7 +31,7 @@ static DEFINE_PER_CPU(void __iomem *, sswi_cpu_regs);
>
> static void thead_aclint_sswi_ipi_send(unsigned int cpu)
> {
> - writel_relaxed(0x1, per_cpu(sswi_cpu_regs, cpu));
> + writel(0x1, per_cpu(sswi_cpu_regs, cpu));
> }
>
> static void thead_aclint_sswi_ipi_clear(void)
> --
> 2.20.1
>
>
> _______________________________________________
> linux-riscv mailing list
> linux-riscv@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-riscv
next prev parent reply other threads:[~2025-01-16 21:09 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-01-16 12:07 [PATCH] irqchip: riscv: Order normal writes and IPI writes Xu Lu
2025-01-16 21:09 ` Charlie Jenkins [this message]
2025-01-17 10:35 ` Thomas Gleixner
2025-01-17 15:53 ` Anup Patel
2025-01-20 7:37 ` Thomas Gleixner
2025-01-20 11:05 ` [External] " Xu Lu
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