Re: [PATCH] PCI: uniphier: Take lock in INTX irq_{mask,unmask,ack} callbacks
From: Bjorn Helgaas <helgaas@kernel.org>
Date: 2021-08-19 11:29:13
Also in:
linux-pci, lkml
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.
quoted hunk ↗ jump to hunk
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
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