Messages in this thread Patch in this message | | | Date | Tue, 26 Jan 2021 12:25:08 +0000 | From | Marc Zyngier <> | Subject | Re: [v7,4/7] PCI: mediatek-gen3: Add INTx support |
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On 2021-01-13 11:39, Jianjun Wang wrote: > Add INTx support for MediaTek Gen3 PCIe controller. > > Signed-off-by: Jianjun Wang <jianjun.wang@mediatek.com> > Acked-by: Ryder Lee <ryder.lee@mediatek.com> > --- > drivers/pci/controller/pcie-mediatek-gen3.c | 163 ++++++++++++++++++++ > 1 file changed, 163 insertions(+) > > diff --git a/drivers/pci/controller/pcie-mediatek-gen3.c > b/drivers/pci/controller/pcie-mediatek-gen3.c > index c00ea7c167de..7979a2856c35 100644 > --- a/drivers/pci/controller/pcie-mediatek-gen3.c > +++ b/drivers/pci/controller/pcie-mediatek-gen3.c > @@ -9,6 +9,9 @@ > #include <linux/clk.h> > #include <linux/delay.h> > #include <linux/iopoll.h> > +#include <linux/irq.h> > +#include <linux/irqchip/chained_irq.h> > +#include <linux/irqdomain.h> > #include <linux/kernel.h> > #include <linux/module.h> > #include <linux/of_address.h> > @@ -49,6 +52,12 @@ > #define PCIE_LINK_STATUS_REG 0x154 > #define PCIE_PORT_LINKUP BIT(8) > > +#define PCIE_INT_ENABLE_REG 0x180 > +#define PCIE_INTX_SHIFT 24 > +#define PCIE_INTX_MASK GENMASK(27, 24)
I guess this '24' is actually PCIE_INTX_SHIFT? In this case, please write it as
GENMASK(PCIE_INTX_SHIFT + PCI_NUM_INTX - 1, PCIE_INTX_SHIFT)
to make it clear that you are dealing with one bit per INTx.
> + > +#define PCIE_INT_STATUS_REG 0x184 > + > #define PCIE_TRANS_TABLE_BASE_REG 0x800 > #define PCIE_ATR_SRC_ADDR_MSB_OFFSET 0x4 > #define PCIE_ATR_TRSL_ADDR_LSB_OFFSET 0x8 > @@ -77,6 +86,8 @@ > * @phy: PHY controller block > * @clks: PCIe clocks > * @num_clks: PCIe clocks count for this port > + * @irq: PCIe controller interrupt number > + * @intx_domain: legacy INTx IRQ domain > */ > struct mtk_pcie_port { > struct device *dev; > @@ -87,6 +98,9 @@ struct mtk_pcie_port { > struct phy *phy; > struct clk_bulk_data *clks; > int num_clks; > + > + int irq; > + struct irq_domain *intx_domain; > }; > > /** > @@ -266,6 +280,149 @@ static int mtk_pcie_startup_port(struct > mtk_pcie_port *port) > return 0; > } > > +static int mtk_pcie_set_affinity(struct irq_data *data, > + const struct cpumask *mask, bool force) > +{ > + return -EINVAL; > +} > + > +static void mtk_intx_mask(struct irq_data *data) > +{ > + struct mtk_pcie_port *port = irq_data_get_irq_chip_data(data); > + u32 val; > + > + val = readl_relaxed(port->base + PCIE_INT_ENABLE_REG); > + val &= ~BIT(data->hwirq + PCIE_INTX_SHIFT); > + writel_relaxed(val, port->base + PCIE_INT_ENABLE_REG);
This is missing some locking. Otherwise, two concurrent mask/unmask for different interrupts will corrupt each other's state.
> +} > + > +static void mtk_intx_unmask(struct irq_data *data) > +{ > + struct mtk_pcie_port *port = irq_data_get_irq_chip_data(data); > + u32 val; > + > + val = readl_relaxed(port->base + PCIE_INT_ENABLE_REG); > + val |= BIT(data->hwirq + PCIE_INTX_SHIFT); > + writel_relaxed(val, port->base + PCIE_INT_ENABLE_REG);
Same thing here.
> +} > + > +/** > + * mtk_intx_eoi > + * @data: pointer to chip specific data > + * > + * As an emulated level IRQ, its interrupt status will remain > + * until the corresponding de-assert message is received; hence that > + * the status can only be cleared when the interrupt has been > serviced. > + */ > +static void mtk_intx_eoi(struct irq_data *data) > +{ > + struct mtk_pcie_port *port = irq_data_get_irq_chip_data(data); > + unsigned long hwirq; > + > + hwirq = data->hwirq + PCIE_INTX_SHIFT; > + writel_relaxed(BIT(hwirq), port->base + PCIE_INT_STATUS_REG); > +} > + > +static struct irq_chip mtk_intx_irq_chip = { > + .irq_mask = mtk_intx_mask, > + .irq_unmask = mtk_intx_unmask, > + .irq_eoi = mtk_intx_eoi, > + .irq_set_affinity = mtk_pcie_set_affinity, > + .name = "PCIe",
nit: "PCIe" is not really descriptive. "INTx" would be a bit better.
> +}; > + > +static int mtk_pcie_intx_map(struct irq_domain *domain, unsigned int > irq, > + irq_hw_number_t hwirq) > +{ > + irq_set_chip_and_handler_name(irq, &mtk_intx_irq_chip, > + handle_fasteoi_irq, "INTx"); > + irq_set_chip_data(irq, domain->host_data);
You probably want to set the chip_data *before* wiring the handler, as otherwise you could end-up with a NULL pointer in any of the callbacks if the interrupt fires between the two.
> + > + return 0; > +} > + > +static const struct irq_domain_ops intx_domain_ops = { > + .map = mtk_pcie_intx_map, > +}; > + > +static int mtk_pcie_init_irq_domains(struct mtk_pcie_port *port, > + struct device_node *node) > +{ > + struct device *dev = port->dev; > + struct device_node *intc_node; > + > + /* Setup INTx */ > + intc_node = of_get_child_by_name(node, "interrupt-controller"); > + if (!intc_node) { > + dev_err(dev, "missing PCIe Intc node\n"); > + return -ENODEV; > + } > + > + port->intx_domain = irq_domain_add_linear(intc_node, PCI_NUM_INTX, > + &intx_domain_ops, port); > + if (!port->intx_domain) { > + dev_err(dev, "failed to get INTx IRQ domain\n"); > + return -ENODEV; > + } > + > + return 0; > +} > + > +static void mtk_pcie_irq_teardown(struct mtk_pcie_port *port) > +{ > + irq_set_chained_handler_and_data(port->irq, NULL, NULL); > + > + if (port->intx_domain) > + irq_domain_remove(port->intx_domain); > + > + irq_dispose_mapping(port->irq); > +} > + > +static void mtk_pcie_irq_handler(struct irq_desc *desc) > +{ > + struct mtk_pcie_port *port = irq_desc_get_handler_data(desc); > + struct irq_chip *irqchip = irq_desc_get_chip(desc); > + unsigned long status; > + unsigned int virq; > + irq_hw_number_t irq_bit = PCIE_INTX_SHIFT; > + > + chained_irq_enter(irqchip, desc); > + > + status = readl_relaxed(port->base + PCIE_INT_STATUS_REG); > + if (status & PCIE_INTX_MASK) {
This "if (status & PCIE_INTX_MASK)" is already implicit from the for_each_set_bit_from() iterator, and you can drop it.
> + for_each_set_bit_from(irq_bit, &status, PCI_NUM_INTX + > + PCIE_INTX_SHIFT) { > + virq = irq_find_mapping(port->intx_domain, > + irq_bit - PCIE_INTX_SHIFT); > + generic_handle_irq(virq); > + } > + } > + > + chained_irq_exit(irqchip, desc); > +} > + > +static int mtk_pcie_setup_irq(struct mtk_pcie_port *port, > + struct device_node *node) > +{ > + struct device *dev = port->dev; > + struct platform_device *pdev = to_platform_device(dev); > + int err; > + > + err = mtk_pcie_init_irq_domains(port, node); > + if (err) { > + dev_err(dev, "failed to init PCIe IRQ domain\n"); > + return err; > + } > + > + port->irq = platform_get_irq(pdev, 0); > + if (port->irq < 0) > + return port->irq; > + > + irq_set_chained_handler_and_data(port->irq, mtk_pcie_irq_handler, > port);
You seem to be missing something that will mask all INTx interrupts as an initial state.
> + > + return 0; > +} > + > static int mtk_pcie_clk_init(struct mtk_pcie_port *port) > { > int ret; > @@ -388,6 +545,10 @@ static int mtk_pcie_setup(struct mtk_pcie_port > *port) > goto err_setup; > } > > + err = mtk_pcie_setup_irq(port, dev->of_node); > + if (err) > + goto err_setup; > + > dev_info(dev, "PCIe link up success!\n"); > > return 0; > @@ -423,6 +584,7 @@ static int mtk_pcie_probe(struct platform_device > *pdev) > > err = pci_host_probe(host); > if (err) { > + mtk_pcie_irq_teardown(port); > mtk_pcie_power_down(port); > return err; > } > @@ -440,6 +602,7 @@ static int mtk_pcie_remove(struct platform_device > *pdev) > pci_remove_root_bus(host->bus); > pci_unlock_rescan_remove(); > > + mtk_pcie_irq_teardown(port); > mtk_pcie_power_down(port); > > return 0;
Thanks,
M. -- Jazz is not dead. It just smells funny...
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