diff mbox series

[v7,4/7] PCI: mediatek-gen3: Add INTx support

Message ID 20210113114001.5804-5-jianjun.wang@mediatek.com
State New
Headers show
Series PCI: mediatek: Add new generation controller support | expand

Commit Message

Jianjun Wang (王建军) Jan. 13, 2021, 11:39 a.m. UTC
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(+)

Comments

Marc Zyngier Jan. 26, 2021, 12:25 p.m. UTC | #1
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...
Jianjun Wang (王建军) Jan. 27, 2021, 1:09 p.m. UTC | #2
On Tue, 2021-01-26 at 12:25 +0000, Marc Zyngier wrote:
> 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.


Yes, I will fix it in the next version, thanks for your review.
> 

> > +

> > +#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.


Yes, the INTx default state of this chip is disabled, but there are
still risks for driver use, I will add mask all INTx interrupts to
mtk_pcie_startup_port function in the next version.

Thanks.
> 

> > +

> > +	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.
diff mbox series

Patch

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)
+
+#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);
+}
+
+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);
+}
+
+/**
+ * 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",
+};
+
+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);
+
+	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) {
+		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);
+
+	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;