This is a note to let you know that I've just added the patch titled PCI: uniphier: Serialize INTx masking/unmasking and fix the bit operation to the 5.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: pci-uniphier-serialize-intx-masking-unmasking-and-fi.patch and it can be found in the queue-5.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 4162c118698c6d7b34af85f89c3410c53d46e6ab Author: Kunihiko Hayashi <hayashi.kunihiko@xxxxxxxxxxxxx> Date: Sat Sep 18 09:22:59 2021 +0900 PCI: uniphier: Serialize INTx masking/unmasking and fix the bit operation [ Upstream commit 4caab28a6215da5f3c1b505ff08810bc6acfe365 ] The condition register PCI_RCV_INTX is used in irq_mask() and irq_unmask() callbacks. Accesses to register can occur at the same time without a lock. Add a lock into each callback to prevent the issue. And INTX mask and unmask fields in PCL_RCV_INTX register should only be set/reset for each bit. Clearing by PCL_RCV_INTX_ALL_MASK should be removed. INTX status fields in PCL_RCV_INTX register only indicates each INTX interrupt status, so the handler can't clear by writing 1 to the field. The status is expected to be cleared by the interrupt origin. The ack function has no meaning, so should remove it. Suggested-by: Pali Rohár <pali@xxxxxxxxxx> Link: https://lore.kernel.org/r/1631924579-24567-1-git-send-email-hayashi.kunihiko@xxxxxxxxxxxxx Fixes: 7e6d5cd88a6f ("PCI: uniphier: Add UniPhier PCIe host controller support") Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@xxxxxxxxxxxxx> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx> Acked-by: Pali Rohár <pali@xxxxxxxxxx> Acked-by: Marc Zyngier <maz@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/pci/controller/dwc/pcie-uniphier.c b/drivers/pci/controller/dwc/pcie-uniphier.c index 7e8bad3267701..5cf699dbee7ca 100644 --- a/drivers/pci/controller/dwc/pcie-uniphier.c +++ b/drivers/pci/controller/dwc/pcie-uniphier.c @@ -168,30 +168,21 @@ static void uniphier_pcie_irq_enable(struct uniphier_pcie_priv *priv) writel(PCL_RCV_INTX_ALL_ENABLE, priv->base + PCL_RCV_INTX); } -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); - u32 val; - - 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); -} - 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) @@ -199,17 +190,20 @@ 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 = { .name = "PCI", - .irq_ack = uniphier_pcie_irq_ack, .irq_mask = uniphier_pcie_irq_mask, .irq_unmask = uniphier_pcie_irq_unmask, };