From: Bjorn Helgaas <helgaas@kernel.org>
To: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Cc: "Lorenzo Pieralisi" <lorenzo.pieralisi@arm.com>,
"Rob Herring" <robh@kernel.org>,
"Krzysztof Wilczy���ski" <kw@linux.com>,
"Bjorn Helgaas" <bhelgaas@google.com>,
"Pali Roh���r" <pali@kernel.org>,
"Masami Hiramatsu" <mhiramat@kernel.org>,
linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] PCI: uniphier: Take lock in INTX irq_{mask,unmask,ack} callbacks
Date: Thu, 19 Aug 2021 06:29:08 -0500 [thread overview]
Message-ID: <20210819112908.GA3188927@bjorn-Precision-5520> (raw)
In-Reply-To: <1629370566-29984-1-git-send-email-hayashi.kunihiko@socionext.com>
Possibly update subject to be more descriptive, along lines of:
Serialize INTx masking/unmasking
On Thu, Aug 19, 2021 at 07:56:06PM +0900, Kunihiko Hayashi wrote:
> The same condition register PCI_RCV_INTX is used in irq_mask(),
> irq_unmask() and irq_ack() callbacks. Accesses to register can occur at the
> same time without lock.
> This introduces a lock into the callbacks to prevent the issue.
Rewrap into a single paragraph or add blank line between paragraphs.
s/This introduces/Add/ to make this an imperative description of what
you want this patch to do. No need for "This" since the context is
obvious.
> Fixes: 7e6d5cd88a6f ("PCI: uniphier: Add UniPhier PCIe host controller support")
> Suggested-by: Pali Rohár <pali@kernel.org>
> Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
> ---
> drivers/pci/controller/dwc/pcie-uniphier.c | 15 +++++++++++++++
> 1 file changed, 15 insertions(+)
>
> diff --git a/drivers/pci/controller/dwc/pcie-uniphier.c b/drivers/pci/controller/dwc/pcie-uniphier.c
> index ebe43e9..5075714 100644
> --- a/drivers/pci/controller/dwc/pcie-uniphier.c
> +++ b/drivers/pci/controller/dwc/pcie-uniphier.c
> @@ -186,12 +186,17 @@ static void uniphier_pcie_irq_ack(struct irq_data *d)
> struct pcie_port *pp = irq_data_get_irq_chip_data(d);
> struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
> struct uniphier_pcie_priv *priv = to_uniphier_pcie(pci);
> + unsigned long flags;
> u32 val;
>
> + raw_spin_lock_irqsave(&pp->lock, flags);
> +
> val = readl(priv->base + PCL_RCV_INTX);
> val &= ~PCL_RCV_INTX_ALL_STATUS;
> val |= BIT(irqd_to_hwirq(d) + PCL_RCV_INTX_STATUS_SHIFT);
> writel(val, priv->base + PCL_RCV_INTX);
> +
> + raw_spin_unlock_irqrestore(&pp->lock, flags);
> }
>
> static void uniphier_pcie_irq_mask(struct irq_data *d)
> @@ -199,12 +204,17 @@ static void uniphier_pcie_irq_mask(struct irq_data *d)
> struct pcie_port *pp = irq_data_get_irq_chip_data(d);
> struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
> struct uniphier_pcie_priv *priv = to_uniphier_pcie(pci);
> + unsigned long flags;
> u32 val;
>
> + raw_spin_lock_irqsave(&pp->lock, flags);
> +
> val = readl(priv->base + PCL_RCV_INTX);
> val &= ~PCL_RCV_INTX_ALL_MASK;
> val |= BIT(irqd_to_hwirq(d) + PCL_RCV_INTX_MASK_SHIFT);
> writel(val, priv->base + PCL_RCV_INTX);
> +
> + raw_spin_unlock_irqrestore(&pp->lock, flags);
> }
>
> static void uniphier_pcie_irq_unmask(struct irq_data *d)
> @@ -212,12 +222,17 @@ static void uniphier_pcie_irq_unmask(struct irq_data *d)
> struct pcie_port *pp = irq_data_get_irq_chip_data(d);
> struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
> struct uniphier_pcie_priv *priv = to_uniphier_pcie(pci);
> + unsigned long flags;
> u32 val;
>
> + raw_spin_lock_irqsave(&pp->lock, flags);
> +
> val = readl(priv->base + PCL_RCV_INTX);
> val &= ~PCL_RCV_INTX_ALL_MASK;
> val &= ~BIT(irqd_to_hwirq(d) + PCL_RCV_INTX_MASK_SHIFT);
> writel(val, priv->base + PCL_RCV_INTX);
> +
> + raw_spin_unlock_irqrestore(&pp->lock, flags);
> }
>
> static struct irq_chip uniphier_pcie_irq_chip = {
> --
> 2.7.4
>
next prev parent reply other threads:[~2021-08-19 11:29 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-19 10:56 [PATCH] PCI: uniphier: Take lock in INTX irq_{mask,unmask,ack} callbacks Kunihiko Hayashi
2021-08-19 11:29 ` Bjorn Helgaas [this message]
2021-08-19 23:03 ` Kunihiko Hayashi
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