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SubjectRE: [PATCH v7 2/2] PCI: xilinx-cpm: Add Versal CPM Root Port driver
Date
> Bharat,
>
> On 2020-05-07 12:58, Bharat Kumar Gogada wrote:
> > - Add support for Versal CPM as Root Port.
> > - The Versal ACAP devices include CCIX-PCIe Module (CPM). The
> > integrated
> > block for CPM along with the integrated bridge can function
> > as PCIe Root Port.
> > - Bridge error and legacy interrupts in Versal CPM are handled using
> > Versal CPM specific interrupt line.
> >
> > Signed-off-by: Bharat Kumar Gogada <bharat.kumar.gogada@xilinx.com>
> > ---
> > drivers/pci/controller/Kconfig | 9 +
> > drivers/pci/controller/Makefile | 1 +
> > drivers/pci/controller/pcie-xilinx-cpm.c | 506
> > +++++++++++++++++++++++++++++++
> > 3 files changed, 516 insertions(+)
> > create mode 100644 drivers/pci/controller/pcie-xilinx-cpm.c
> >
> > diff --git a/drivers/pci/controller/Kconfig
> > b/drivers/pci/controller/Kconfig index 20bf00f..ca0ae24 100644
> > --- a/drivers/pci/controller/Kconfig
> > +++ b/drivers/pci/controller/Kconfig
> > @@ -81,6 +81,15 @@ config PCIE_XILINX
> > Say 'Y' here if you want kernel to support the Xilinx AXI PCIe
> > Host Bridge driver.
> >
> > +config PCIE_XILINX_CPM
> > + bool "Xilinx Versal CPM host bridge support"
> > + depends on ARCH_ZYNQMP || COMPILE_TEST
> > + select PCI_HOST_COMMON
> > + help
> > + Say 'Y' here if you want kernel support for the
> > + Xilinx Versal CPM host bridge. The driver supports
> > + MSI/MSI-X interrupts using GICv3 ITS feature.
>
> I don't think this last sentense makes any sense here. We usually don't
> mention things that the driver *doesn't* implement.
Agreed, will remove these details.
>
> > +
> > config PCI_XGENE
> > bool "X-Gene PCIe controller"
> > depends on ARM64 || COMPILE_TEST
> > diff --git a/drivers/pci/controller/Makefile
> > b/drivers/pci/controller/Makefile index 01b2502..78dabda 100644
> > --- a/drivers/pci/controller/Makefile
> > +++ b/drivers/pci/controller/Makefile
> > @@ -12,6 +12,7 @@ obj-$(CONFIG_PCI_HOST_COMMON) += pci-host-
> common.o
> > obj-$(CONFIG_PCI_HOST_GENERIC) += pci-host-generic.o
> > obj-$(CONFIG_PCIE_XILINX) += pcie-xilinx.o
> > obj-$(CONFIG_PCIE_XILINX_NWL) += pcie-xilinx-nwl.o
> > +obj-$(CONFIG_PCIE_XILINX_CPM) += pcie-xilinx-cpm.o
> > obj-$(CONFIG_PCI_V3_SEMI) += pci-v3-semi.o
> > obj-$(CONFIG_PCI_XGENE_MSI) += pci-xgene-msi.o
> > obj-$(CONFIG_PCI_VERSATILE) += pci-versatile.o diff --git
> > a/drivers/pci/controller/pcie-xilinx-cpm.c
> > b/drivers/pci/controller/pcie-xilinx-cpm.c
> > new file mode 100644
> > index 0000000..e8c0aa7
> > --- /dev/null
> > +++ b/drivers/pci/controller/pcie-xilinx-cpm.c
> > @@ -0,0 +1,506 @@
> > +// SPDX-License-Identifier: GPL-2.0+
> > +/*
> > + * PCIe host controller driver for Xilinx Versal CPM DMA Bridge
> > + *
> > + * (C) Copyright 2019 - 2020, Xilinx, Inc.
> > + */
> > +
> > +#include <linux/interrupt.h>
> > +#include <linux/irq.h>
> > +#include <linux/irqdomain.h>
> > +#include <linux/kernel.h>
> > +#include <linux/module.h>
> > +#include <linux/of_address.h>
> > +#include <linux/of_pci.h>
> > +#include <linux/of_platform.h>
> > +#include <linux/of_irq.h>
> > +#include <linux/pci.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/pci-ecam.h>
> > +
> > +#include "../pci.h"
> > +
> > +/* Register definitions */
> > +#define XILINX_CPM_PCIE_REG_IDR 0x00000E10
> > +#define XILINX_CPM_PCIE_REG_IMR 0x00000E14
> > +#define XILINX_CPM_PCIE_REG_PSCR 0x00000E1C
> > +#define XILINX_CPM_PCIE_REG_RPSC 0x00000E20
> > +#define XILINX_CPM_PCIE_REG_RPEFR 0x00000E2C
> > +#define XILINX_CPM_PCIE_REG_IDRN 0x00000E38
> > +#define XILINX_CPM_PCIE_REG_IDRN_MASK 0x00000E3C
> > +#define XILINX_CPM_PCIE_MISC_IR_STATUS 0x00000340
> > +#define XILINX_CPM_PCIE_MISC_IR_ENABLE 0x00000348
> > +#define XILINX_CPM_PCIE_MISC_IR_LOCAL BIT(1)
> > +
> > +/* Interrupt registers definitions */
> > +#define XILINX_CPM_PCIE_INTR_LINK_DOWN BIT(0)
> > +#define XILINX_CPM_PCIE_INTR_HOT_RESET BIT(3)
> > +#define XILINX_CPM_PCIE_INTR_CFG_TIMEOUT BIT(8)
> > +#define XILINX_CPM_PCIE_INTR_CORRECTABLE BIT(9)
> > +#define XILINX_CPM_PCIE_INTR_NONFATAL BIT(10)
> > +#define XILINX_CPM_PCIE_INTR_FATAL BIT(11)
> > +#define XILINX_CPM_PCIE_INTR_INTX BIT(16)
> > +#define XILINX_CPM_PCIE_INTR_MSI BIT(17)
> > +#define XILINX_CPM_PCIE_INTR_SLV_UNSUPP BIT(20)
> > +#define XILINX_CPM_PCIE_INTR_SLV_UNEXP BIT(21)
> > +#define XILINX_CPM_PCIE_INTR_SLV_COMPL BIT(22)
> > +#define XILINX_CPM_PCIE_INTR_SLV_ERRP BIT(23)
> > +#define XILINX_CPM_PCIE_INTR_SLV_CMPABT BIT(24)
> > +#define XILINX_CPM_PCIE_INTR_SLV_ILLBUR BIT(25)
> > +#define XILINX_CPM_PCIE_INTR_MST_DECERR BIT(26)
> > +#define XILINX_CPM_PCIE_INTR_MST_SLVERR BIT(27)
> > +#define XILINX_CPM_PCIE_IMR_ALL_MASK 0x1FF39FF9
>
> I assume that this is the logical OR of all the XILINX_CPM_PCIE_INTR_* bits.
> Please express it as such.
Agreed, will change this.
>
> > +#define XILINX_CPM_PCIE_IDR_ALL_MASK 0xFFFFFFFF
> > +#define XILINX_CPM_PCIE_IDRN_MASK GENMASK(19, 16)
> > +#define XILINX_CPM_PCIE_INTR_CFG_PCIE_TIMEOUT BIT(4)
> > +#define XILINX_CPM_PCIE_INTR_CFG_ERR_POISON BIT(12)
> > +#define XILINX_CPM_PCIE_INTR_PME_TO_ACK_RCVD BIT(15)
> > +#define XILINX_CPM_PCIE_INTR_PM_PME_RCVD BIT(17)
>
> So we have two definitions for bit 17... Given that nothing uses the MSI
> version, I assume it is useless...
>
> > +#define XILINX_CPM_PCIE_INTR_SLV_PCIE_TIMEOUT BIT(28)
>
> Please group all the XILINX_CPM_PCIE_INTR_* together.
>
Agreed, will change this.
> > +#define XILINX_CPM_PCIE_IDRN_SHIFT 16
> > +
> > +/* Root Port Error FIFO Read Register definitions */
> > +#define XILINX_CPM_PCIE_RPEFR_ERR_VALID BIT(18)
> > +#define XILINX_CPM_PCIE_RPEFR_REQ_ID GENMASK(15, 0)
> > +#define XILINX_CPM_PCIE_RPEFR_ALL_MASK 0xFFFFFFFF
> > +
> > +/* Root Port Status/control Register definitions */
> > +#define XILINX_CPM_PCIE_REG_RPSC_BEN BIT(0)
> > +
> > +/* Phy Status/Control Register definitions */
> > +#define XILINX_CPM_PCIE_REG_PSCR_LNKUP BIT(11)
> > +
> > +/**
> > + * struct xilinx_cpm_pcie_port - PCIe port information
> > + * @reg_base: Bridge Register Base
> > + * @cpm_base: CPM System Level Control and Status Register(SLCR) Base
> > + * @dev: Device pointer
> > + * @leg_domain: Legacy IRQ domain pointer
>
> leg, arm, thumb, limb... Given that oyu use the 'intx' description all over the
> driver, please be consistent and name this intx_domain.
>
> > + * @cfg: Holds mappings of config space window
> > + * @irq_misc: Legacy and error interrupt number
>
> Let's face it, this is the *only* interrupt this thing as, so the 'misc'
> is supperfluous.
>
> > + * @leg_mask_lock: lock for legacy interrupts */ struct
> > +xilinx_cpm_pcie_port {
> > + void __iomem *reg_base;
> > + void __iomem *cpm_base;
> > + struct device *dev;
> > + struct irq_domain *leg_domain;
> > + struct pci_config_window *cfg;
> > + int irq_misc;
> > + raw_spinlock_t leg_mask_lock;
> > +};
> > +
> > +static inline u32 pcie_read(struct xilinx_cpm_pcie_port *port, u32
> > reg)
> > +{
> > + return readl(port->reg_base + reg);
>
> There is no need for enforced ordering with non-device writes, so you can
> turn this into readl_relaxed. You can also drop the inline, as the compiler
> will do the right thing for you.
>
Agreed, will change to readl_relaxed.

> > +}
> > +
> > +static inline void pcie_write(struct xilinx_cpm_pcie_port *port,
> > + u32 val, u32 reg)
> > +{
> > + writel(val, port->reg_base + reg);
>
> Same thing.
>
> > +}
> > +
> > +static inline bool cpm_pcie_link_up(struct xilinx_cpm_pcie_port
> > +*port) {
> > + return (pcie_read(port, XILINX_CPM_PCIE_REG_PSCR) &
> > + XILINX_CPM_PCIE_REG_PSCR_LNKUP) ? 1 : 0;
>
> If you are making the return value a bool, you might as well return
> true/false. But that's a cumbersome way to write:
>
> return pcie_read(port, XILINX_CPM_PCIE_REG_PSCR) &
> XILINX_CPM_PCIE_REG_PSCR_LNKUP;
>
> > +}
> > +
> > +/**
> > + * xilinx_cpm_pcie_clear_err_interrupts - Clear Error Interrupts
> > + * @port: PCIe port information
> > + */
> > +static void cpm_pcie_clear_err_interrupts(struct xilinx_cpm_pcie_port
> > *port)
> > +{
> > + unsigned long val = pcie_read(port, XILINX_CPM_PCIE_REG_RPEFR);
> > +
> > + if (val & XILINX_CPM_PCIE_RPEFR_ERR_VALID) {
> > + dev_dbg(port->dev, "Requester ID %lu\n",
> > + val & XILINX_CPM_PCIE_RPEFR_REQ_ID);
> > + pcie_write(port, XILINX_CPM_PCIE_RPEFR_ALL_MASK,
> > + XILINX_CPM_PCIE_REG_RPEFR);
> > + }
> > +}
> > +
> > +static void xilinx_cpm_mask_leg_irq(struct irq_data *data) {
> > + struct irq_desc *desc = irq_to_desc(data->irq);
> > + struct xilinx_cpm_pcie_port *port;
> > + unsigned long flags;
> > + u32 mask;
> > + u32 val;
> > +
> > + port = irq_desc_get_chip_data(desc);
>
> port = irq_data_get_irq_chip_data(data);
>
> You should never have to get the irq_desc (and using irq_to_desc() is a
> prettyodd way to get it when you already have the irq_data).
>
> > + mask = (1 << data->hwirq) << XILINX_CPM_PCIE_IDRN_SHIFT;
>
> Also known as BIT(data->hwirq + XILINX_CPM_PCIE_IDRN_SHIFT).
>
> > + raw_spin_lock_irqsave(&port->leg_mask_lock, flags);
> > + val = pcie_read(port, XILINX_CPM_PCIE_REG_IDRN_MASK);
> > + pcie_write(port, (val & (~mask)),
> XILINX_CPM_PCIE_REG_IDRN_MASK);
> > + raw_spin_unlock_irqrestore(&port->leg_mask_lock, flags); }
> > +
> > +static void xilinx_cpm_unmask_leg_irq(struct irq_data *data) {
> > + struct irq_desc *desc = irq_to_desc(data->irq);
> > + struct xilinx_cpm_pcie_port *port;
> > + unsigned long flags;
> > + u32 mask;
> > + u32 val;
> > +
> > + port = irq_desc_get_chip_data(desc);
> > + mask = (1 << data->hwirq) << XILINX_CPM_PCIE_IDRN_SHIFT;
> > + raw_spin_lock_irqsave(&port->leg_mask_lock, flags);
> > + val = pcie_read(port, XILINX_CPM_PCIE_REG_IDRN_MASK);
> > + pcie_write(port, (val | mask), XILINX_CPM_PCIE_REG_IDRN_MASK);
> > + raw_spin_unlock_irqrestore(&port->leg_mask_lock, flags); }
> > +
> > +static struct irq_chip xilinx_cpm_leg_irq_chip = {
> > + .name = "xilinx_cpm_pcie:legacy",
>
> "INTx" is a good enough description.
>
> > + .irq_enable = xilinx_cpm_unmask_leg_irq,
> > + .irq_disable = xilinx_cpm_mask_leg_irq,
> > + .irq_mask = xilinx_cpm_mask_leg_irq,
> > + .irq_unmask = xilinx_cpm_unmask_leg_irq,
>
> This makes no sense. If enable/disable have the same implementation as
> unmask/mask, then enable/disable is pretty useless. Please drop them.
>
Agreed, will drop these methods.
> > +};
> > +
> > +/**
> > + * xilinx_cpm_pcie_intx_map - Set the handler for the INTx and mark
> > IRQ as valid
> > + * @domain: IRQ domain
> > + * @irq: Virtual IRQ number
> > + * @hwirq: HW interrupt number
> > + *
> > + * Return: Always returns 0.
> > + */
> > +static int xilinx_cpm_pcie_intx_map(struct irq_domain *domain,
> > + unsigned int irq, irq_hw_number_t hwirq)
> {
> > + irq_set_chip_and_handler(irq, &xilinx_cpm_leg_irq_chip,
> > + handle_level_irq);
> > + irq_set_chip_data(irq, domain->host_data);
> > + irq_set_status_flags(irq, IRQ_LEVEL);
> > +
> > + return 0;
> > +}
> > +
> > +/* INTx IRQ Domain operations */
> > +static const struct irq_domain_ops intx_domain_ops = {
> > + .map = xilinx_cpm_pcie_intx_map,
> > +};
> > +
> > +/**
> > + * xilinx_cpm_pcie_intr_handler - Interrupt Service Handler
> > + * @irq: IRQ number
> > + * @data: PCIe port information
> > + *
> > + * Return: IRQ_HANDLED on success and IRQ_NONE on failure */ static
> > +irqreturn_t xilinx_cpm_pcie_intr_handler(int irq, void *data) {
> > + struct xilinx_cpm_pcie_port *port = data;
> > + struct device *dev = port->dev;
> > + u32 val, mask, status, bit;
> > + unsigned long intr_val;
> > +
> > + /* Read interrupt decode and mask registers */
> > + val = pcie_read(port, XILINX_CPM_PCIE_REG_IDR);
> > + mask = pcie_read(port, XILINX_CPM_PCIE_REG_IMR);
> > +
> > + status = val & mask;
> > + if (!status)
> > + return IRQ_NONE;
> > +
> > + if (status & XILINX_CPM_PCIE_INTR_LINK_DOWN)
> > + dev_warn(dev, "Link Down\n");
> > +
> > + if (status & XILINX_CPM_PCIE_INTR_HOT_RESET)
> > + dev_info(dev, "Hot reset\n");
> > +
> > + if (status & XILINX_CPM_PCIE_INTR_CFG_TIMEOUT)
> > + dev_warn(dev, "ECAM access timeout\n");
>
> There is a certain sense of repetition here. It really begs the question of
> *why* you want to take these interrupts if all you do is spam the console
> with warnings, not taking any action to potentially remedy the problem.
>
We use this information if user faces an issue to track down possible cause.
> > +
> > + if (status & XILINX_CPM_PCIE_INTR_CORRECTABLE) {
> > + dev_warn(dev, "Correctable error message\n");
> > + cpm_pcie_clear_err_interrupts(port);
> > + }
> > +
> > + if (status & XILINX_CPM_PCIE_INTR_NONFATAL) {
> > + dev_warn(dev, "Non fatal error message\n");
> > + cpm_pcie_clear_err_interrupts(port);
> > + }
> > +
> > + if (status & XILINX_CPM_PCIE_INTR_FATAL) {
> > + dev_warn(dev, "Fatal error message\n");
> > + cpm_pcie_clear_err_interrupts(port);
> > + }
> > +
> > + if (status & XILINX_CPM_PCIE_INTR_INTX) {
> > + /* Handle INTx Interrupt */
> > + intr_val = pcie_read(port, XILINX_CPM_PCIE_REG_IDRN);
> > + intr_val = intr_val >> XILINX_CPM_PCIE_IDRN_SHIFT;
> > +
> > + for_each_set_bit(bit, &intr_val, PCI_NUM_INTX)
> > + generic_handle_irq(irq_find_mapping(port-
> >leg_domain,
> > + bit));
>
> That's a firm no. We don't demux chained handlers in an interrupt handler.
> It may work for now, but it will eventually break. And to be clear, this whole
> function needs to die. By the look of it, this PCie controller implements
> *TWO* interrupt multiplexers:
>
> - one that muxes all the ILINX_CPM_PCIE_INTR_* events onto a single top-
> level IRQ
> - another one that muxes all INTX lines onto XILINX_CPM_PCIE_INTR_INTX
>
> Please implement the whole thing as described above.
Agreed, thanks for resolving this.
>
> > + }
> > +
> > + if (status & XILINX_CPM_PCIE_INTR_SLV_UNSUPP)
> > + dev_warn(dev, "Slave unsupported request\n");
> > +
> > + if (status & XILINX_CPM_PCIE_INTR_SLV_UNEXP)
> > + dev_warn(dev, "Slave unexpected completion\n");
> > +
> > + if (status & XILINX_CPM_PCIE_INTR_SLV_COMPL)
> > + dev_warn(dev, "Slave completion timeout\n");
> > +
> > + if (status & XILINX_CPM_PCIE_INTR_SLV_ERRP)
> > + dev_warn(dev, "Slave Error Poison\n");
> > +
> > + if (status & XILINX_CPM_PCIE_INTR_SLV_CMPABT)
> > + dev_warn(dev, "Slave Completer Abort\n");
> > +
> > + if (status & XILINX_CPM_PCIE_INTR_SLV_ILLBUR)
> > + dev_warn(dev, "Slave Illegal Burst\n");
> > +
> > + if (status & XILINX_CPM_PCIE_INTR_MST_DECERR)
> > + dev_warn(dev, "Master decode error\n");
> > +
> > + if (status & XILINX_CPM_PCIE_INTR_MST_SLVERR)
> > + dev_warn(dev, "Master slave error\n");
> > +
> > + if (status & XILINX_CPM_PCIE_INTR_CFG_PCIE_TIMEOUT)
> > + dev_warn(dev, "PCIe ECAM access timeout\n");
> > +
> > + if (status & XILINX_CPM_PCIE_INTR_CFG_ERR_POISON)
> > + dev_warn(dev, "ECAM poisoned completion received\n");
> > +
> > + if (status & XILINX_CPM_PCIE_INTR_PME_TO_ACK_RCVD)
> > + dev_warn(dev, "PME_TO_ACK message received\n");
> > +
> > + if (status & XILINX_CPM_PCIE_INTR_PM_PME_RCVD)
> > + dev_warn(dev, "PM_PME message received\n");
> > +
> > + if (status & XILINX_CPM_PCIE_INTR_SLV_PCIE_TIMEOUT)
> > + dev_warn(dev, "PCIe completion timeout received\n");
>
> I'm pretty sure there is a slightly better way to write this...
>
> > +
> > + /* Clear the Interrupt Decode register */
> > + pcie_write(port, status, XILINX_CPM_PCIE_REG_IDR);
> > +
> > + /*
> > + * XILINX_CPM_PCIE_MISC_IR_STATUS register is mapped to
> > + * CPM SLCR block.
> > + */
> > + val = readl(port->cpm_base + XILINX_CPM_PCIE_MISC_IR_STATUS);
> > + if (val)
> > + writel(val, port->cpm_base +
> XILINX_CPM_PCIE_MISC_IR_STATUS);
> > +
> > + return IRQ_HANDLED;
> > +}
> > +
> > +/**
> > + * xilinx_cpm_pcie_init_irq_domain - Initialize IRQ domain
> > + * @port: PCIe port information
> > + *
> > + * Return: '0' on success and error value on failure */ static int
> > +xilinx_cpm_pcie_init_irq_domain(struct xilinx_cpm_pcie_port
> > *port)
> > +{
> > + struct device *dev = port->dev;
> > + struct device_node *node = dev->of_node;
> > + struct device_node *pcie_intc_node;
> > +
> > + /* Setup INTx */
> > + pcie_intc_node = of_get_next_child(node, NULL);
> > + if (!pcie_intc_node) {
> > + dev_err(dev, "No PCIe Intc node found\n");
> > + return -EINVAL;
> > + }
> > +
> > + port->leg_domain = irq_domain_add_linear(pcie_intc_node,
> > PCI_NUM_INTX,
> > + &intx_domain_ops,
> > + port);
> > + of_node_put(pcie_intc_node);
> > + if (!port->leg_domain) {
> > + dev_err(dev, "Failed to get a INTx IRQ domain\n");
> > + return -ENOMEM;
> > + }
> > +
> > + raw_spin_lock_init(&port->leg_mask_lock);
> > + return 0;
> > +}
> > +
> > +/**
> > + * xilinx_cpm_pcie_init_port - Initialize hardware
> > + * @port: PCIe port information
> > + */
> > +static void xilinx_cpm_pcie_init_port(struct xilinx_cpm_pcie_port
> > *port)
> > +{
> > + if (cpm_pcie_link_up(port))
> > + dev_info(port->dev, "PCIe Link is UP\n");
> > + else
> > + dev_info(port->dev, "PCIe Link is DOWN\n");
> > +
> > + /* Disable all interrupts */
> > + pcie_write(port, ~XILINX_CPM_PCIE_IDR_ALL_MASK,
> > + XILINX_CPM_PCIE_REG_IMR);
> > +
> > + /* Clear pending interrupts */
> > + pcie_write(port, pcie_read(port, XILINX_CPM_PCIE_REG_IDR) &
> > + XILINX_CPM_PCIE_IMR_ALL_MASK,
> > + XILINX_CPM_PCIE_REG_IDR);
> > +
> > + /* Enable all interrupts */
> > + pcie_write(port, XILINX_CPM_PCIE_IMR_ALL_MASK,
> > + XILINX_CPM_PCIE_REG_IMR);
> > + pcie_write(port, XILINX_CPM_PCIE_IDRN_MASK,
> > + XILINX_CPM_PCIE_REG_IDRN_MASK);
>
> No. We don't enable interrupts randomly. They need a handler registered
> with the core IRq subsystem *first*, which is why this needs to be hooked in
> as a proper irqchip, and each event handled individualy.
>
> > +
> > + /*
> > + * XILINX_CPM_PCIE_MISC_IR_ENABLE register is mapped to
> > + * CPM SLCR block.
> > + */
> > + writel(XILINX_CPM_PCIE_MISC_IR_LOCAL,
> > + port->cpm_base + XILINX_CPM_PCIE_MISC_IR_ENABLE);
> > + /* Enable the Bridge enable bit */
> > + pcie_write(port, pcie_read(port, XILINX_CPM_PCIE_REG_RPSC) |
> > + XILINX_CPM_PCIE_REG_RPSC_BEN,
> > + XILINX_CPM_PCIE_REG_RPSC);
> > +}
> > +
> > +static int xilinx_cpm_request_misc_irq(struct xilinx_cpm_pcie_port
> > *port)
> > +{
> > + struct device *dev = port->dev;
> > + struct platform_device *pdev = to_platform_device(dev);
> > + int err;
> > +
> > + port->irq_misc = platform_get_irq(pdev, 0);
> > + if (port->irq_misc <= 0) {
>
> If 0 is an error, how do you distinguish it from the non-error case?
>
> > + dev_err(dev, "Unable to find misc IRQ line\n");
> > + return port->irq_misc;
> > + }
> > +
> > + err = devm_request_irq(dev, port->irq_misc,
> > + xilinx_cpm_pcie_intr_handler,
> > + IRQF_SHARED | IRQF_NO_THREAD,
> > + "xilinx-pcie", port);
> > + if (err) {
> > + dev_err(dev, "unable to request misc IRQ line %d\n",
> > + port->irq_misc);
> > + return err;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +/**
> > + * xilinx_cpm_pcie_parse_dt - Parse Device tree
> > + * @port: PCIe port information
> > + * @bus_range: Bus resource
> > + *
> > + * Return: '0' on success and error value on failure */ static int
> > +xilinx_cpm_pcie_parse_dt(struct xilinx_cpm_pcie_port *port,
> > + struct resource *bus_range)
> > +{
> > + struct device *dev = port->dev;
> > + struct platform_device *pdev = to_platform_device(dev);
> > + struct resource *res;
> > + int err;
> > +
> > + res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
> "cfg");
> > + if (!res)
> > + return -ENXIO;
> > +
> > + port->cfg = pci_ecam_create(dev, res, bus_range,
> > + &pci_generic_ecam_ops);
> > + if (IS_ERR(port->cfg))
> > + return PTR_ERR(port->cfg);
> > +
> > + port->reg_base = port->cfg->win;
> > +
> > + port->cpm_base = devm_platform_ioremap_resource_byname(pdev,
> > + "cpm_slcr");
> > + if (IS_ERR(port->cpm_base))
> > + return PTR_ERR(port->cpm_base);
> > +
> > + err = xilinx_cpm_request_misc_irq(port);
> > + if (err)
> > + return err;
> > +
> > + return 0;
> > +}
> > +
> > +/**
> > + * xilinx_cpm_pcie_probe - Probe function
> > + * @pdev: Platform device pointer
> > + *
> > + * Return: '0' on success and error value on failure */ static int
> > +xilinx_cpm_pcie_probe(struct platform_device *pdev) {
> > + struct xilinx_cpm_pcie_port *port;
> > + struct device *dev = &pdev->dev;
> > + struct pci_host_bridge *bridge;
> > + struct resource *bus_range;
> > + int err;
> > +
> > + bridge = devm_pci_alloc_host_bridge(dev, sizeof(*port));
> > + if (!bridge)
> > + return -ENODEV;
> > +
> > + port = pci_host_bridge_priv(bridge);
> > +
> > + port->dev = dev;
> > +
> > + err = pci_parse_request_of_pci_ranges(dev, &bridge->windows,
> > + &bridge->dma_ranges,
> &bus_range);
> > + if (err) {
> > + dev_err(dev, "Getting bridge resources failed\n");
> > + return err;
> > + }
> > +
> > + err = xilinx_cpm_pcie_parse_dt(port, bus_range);
> > + if (err) {
> > + dev_err(dev, "Parsing DT failed\n");
> > + return err;
> > + }
> > +
> > + xilinx_cpm_pcie_init_port(port);
> > +
> > + err = xilinx_cpm_pcie_init_irq_domain(port);
> > + if (err) {
> > + dev_err(dev, "Failed creating IRQ Domain\n");
> > + return err;
> > + }
> > +
> > + bridge->dev.parent = dev;
> > + bridge->sysdata = port->cfg;
> > + bridge->busnr = port->cfg->busr.start;
> > + bridge->ops = &pci_generic_ecam_ops.pci_ops;
> > + bridge->map_irq = of_irq_parse_and_map_pci;
> > + bridge->swizzle_irq = pci_common_swizzle;
> > +
> > + err = pci_host_probe(bridge);
> > + if (err < 0) {
> > + irq_domain_remove(port->leg_domain);
> > + devm_free_irq(dev, port->irq_misc, port);
>
> Why calling dem_free_irq()? The whole point of using devm* is not to have
> to manage the error handling.
>
> > + return err;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +static const struct of_device_id xilinx_cpm_pcie_of_match[] = {
> > + { .compatible = "xlnx,versal-cpm-host-1.00", },
> > + {}
> > +};
> > +
> > +static struct platform_driver xilinx_cpm_pcie_driver = {
> > + .driver = {
> > + .name = "xilinx-cpm-pcie",
> > + .of_match_table = xilinx_cpm_pcie_of_match,
> > + .suppress_bind_attrs = true,
> > + },
> > + .probe = xilinx_cpm_pcie_probe,
> > +};
> > +
> > +builtin_platform_driver(xilinx_cpm_pcie_driver);
>
> I don't think this driver is in a state where it can be merged. Given that we're
> already at v7 and to save everyone a bit of time, I've written the patch that
> implements the above comments. It compiles, but is probably broken.
> Hopefully you can test it and figure things out.
Hi Marc,
Thanks for your time and inputs.

Regards,
Bharat


>
> M.
>
> From 8b5d158374e59edf26e61c512eeb00ca7c9d891d Mon Sep 17 00:00:00
> 2001
> From: Marc Zyngier <maz@kernel.org>
> Date: Fri, 22 May 2020 16:33:32 +0100
> Subject: [PATCH] PCI: xilinx-cpm: Revamp irq handling
>
> The xilinx-cpm driver missuses the IRQ layer in creative ways.
> It implements a chained interrupt demultiplexer inside a normal handler,
> enables interrupts randomly, and could overall do with a good cleanup.
>
> Instead, implement the IRQ support as two nested chained irqchips, the
> outer one dealing with all the PCIe events, the inner one namaging the INTx
> signals.
>
> Additionally, the whole driver is cleanup-up so that it can make a bit more
> sense to me. YMMV.
>
> Signed-off-by: Marc Zyngier <maz@kernel.org>
> ---
> drivers/pci/controller/Kconfig | 3 +-
> drivers/pci/controller/pcie-xilinx-cpm.c | 427 ++++++++++++++---------
> 2 files changed, 263 insertions(+), 167 deletions(-)
>
> diff --git a/drivers/pci/controller/Kconfig b/drivers/pci/controller/Kconfig
> index 1e0f63865775..d0abd671a7b6 100644
> --- a/drivers/pci/controller/Kconfig
> +++ b/drivers/pci/controller/Kconfig
> @@ -87,8 +87,7 @@ config PCIE_XILINX_CPM
> select PCI_HOST_COMMON
> help
> Say 'Y' here if you want kernel support for the
> - Xilinx Versal CPM host bridge. The driver supports
> - MSI/MSI-X interrupts using GICv3 ITS feature.
> + Xilinx Versal CPM host bridge.
>
> config PCI_XGENE
> bool "X-Gene PCIe controller"
> diff --git a/drivers/pci/controller/pcie-xilinx-cpm.c
> b/drivers/pci/controller/pcie-xilinx-cpm.c
> index e8c0aa757f72..32ed9e7e2676 100644
> --- a/drivers/pci/controller/pcie-xilinx-cpm.c
> +++ b/drivers/pci/controller/pcie-xilinx-cpm.c
> @@ -5,8 +5,11 @@
> * (C) Copyright 2019 - 2020, Xilinx, Inc.
> */
>
> +#include <linux/bitfield.h>
> #include <linux/interrupt.h>
> #include <linux/irq.h>
> +#include <linux/irqchip.h>
> +#include <linux/irqchip/chained_irq.h>
> #include <linux/irqdomain.h>
> #include <linux/kernel.h>
> #include <linux/module.h>
> @@ -33,30 +36,55 @@
> #define XILINX_CPM_PCIE_MISC_IR_LOCAL BIT(1)
>
> /* Interrupt registers definitions */
> -#define XILINX_CPM_PCIE_INTR_LINK_DOWN BIT(0)
> -#define XILINX_CPM_PCIE_INTR_HOT_RESET BIT(3)
> -#define XILINX_CPM_PCIE_INTR_CFG_TIMEOUT BIT(8)
> -#define XILINX_CPM_PCIE_INTR_CORRECTABLE BIT(9)
> -#define XILINX_CPM_PCIE_INTR_NONFATAL BIT(10)
> -#define XILINX_CPM_PCIE_INTR_FATAL BIT(11)
> -#define XILINX_CPM_PCIE_INTR_INTX BIT(16)
> -#define XILINX_CPM_PCIE_INTR_MSI BIT(17)
> -#define XILINX_CPM_PCIE_INTR_SLV_UNSUPP BIT(20)
> -#define XILINX_CPM_PCIE_INTR_SLV_UNEXP BIT(21)
> -#define XILINX_CPM_PCIE_INTR_SLV_COMPL BIT(22)
> -#define XILINX_CPM_PCIE_INTR_SLV_ERRP BIT(23)
> -#define XILINX_CPM_PCIE_INTR_SLV_CMPABT BIT(24)
> -#define XILINX_CPM_PCIE_INTR_SLV_ILLBUR BIT(25)
> -#define XILINX_CPM_PCIE_INTR_MST_DECERR BIT(26)
> -#define XILINX_CPM_PCIE_INTR_MST_SLVERR BIT(27)
> -#define XILINX_CPM_PCIE_IMR_ALL_MASK 0x1FF39FF9
> +#define XILINX_CPM_PCIE_INTR_LINK_DOWN 0
> +#define XILINX_CPM_PCIE_INTR_HOT_RESET 3
> +#define XILINX_CPM_PCIE_INTR_CFG_PCIE_TIMEOUT 4
> +#define XILINX_CPM_PCIE_INTR_CFG_TIMEOUT 8
> +#define XILINX_CPM_PCIE_INTR_CORRECTABLE 9
> +#define XILINX_CPM_PCIE_INTR_NONFATAL 10
> +#define XILINX_CPM_PCIE_INTR_FATAL 11
> +#define XILINX_CPM_PCIE_INTR_CFG_ERR_POISON 12
> +#define XILINX_CPM_PCIE_INTR_PME_TO_ACK_RCVD 15
> +#define XILINX_CPM_PCIE_INTR_INTX 16
> +#define XILINX_CPM_PCIE_INTR_PM_PME_RCVD 17
> +#define XILINX_CPM_PCIE_INTR_SLV_UNSUPP 20
> +#define XILINX_CPM_PCIE_INTR_SLV_UNEXP 21
> +#define XILINX_CPM_PCIE_INTR_SLV_COMPL 22
> +#define XILINX_CPM_PCIE_INTR_SLV_ERRP 23
> +#define XILINX_CPM_PCIE_INTR_SLV_CMPABT 24
> +#define XILINX_CPM_PCIE_INTR_SLV_ILLBUR 25
> +#define XILINX_CPM_PCIE_INTR_MST_DECERR 26
> +#define XILINX_CPM_PCIE_INTR_MST_SLVERR 27
> +#define XILINX_CPM_PCIE_INTR_SLV_PCIE_TIMEOUT 28
> +
> +#define IMR(x) BIT(XILINX_CPM_PCIE_INTR_ ##x)
> +
> +#define XILINX_CPM_PCIE_IMR_ALL_MASK \
> + ( \
> + IMR(LINK_DOWN) | \
> + IMR(HOT_RESET) | \
> + IMR(CFG_PCIE_TIMEOUT) | \
> + IMR(CFG_TIMEOUT) | \
> + IMR(CORRECTABLE) | \
> + IMR(NONFATAL) | \
> + IMR(FATAL) | \
> + IMR(CFG_ERR_POISON) | \
> + IMR(PME_TO_ACK_RCVD) | \
> + IMR(INTX) | \
> + IMR(PM_PME_RCVD) | \
> + IMR(SLV_UNSUPP) | \
> + IMR(SLV_UNEXP) | \
> + IMR(SLV_COMPL) | \
> + IMR(SLV_ERRP) | \
> + IMR(SLV_CMPABT) | \
> + IMR(SLV_ILLBUR) | \
> + IMR(MST_DECERR) | \
> + IMR(MST_SLVERR) | \
> + IMR(SLV_PCIE_TIMEOUT) \
> + )
> +
> #define XILINX_CPM_PCIE_IDR_ALL_MASK 0xFFFFFFFF
> #define XILINX_CPM_PCIE_IDRN_MASK GENMASK(19, 16)
> -#define XILINX_CPM_PCIE_INTR_CFG_PCIE_TIMEOUT BIT(4)
> -#define XILINX_CPM_PCIE_INTR_CFG_ERR_POISON BIT(12)
> -#define XILINX_CPM_PCIE_INTR_PME_TO_ACK_RCVD BIT(15)
> -#define XILINX_CPM_PCIE_INTR_PM_PME_RCVD BIT(17)
> -#define XILINX_CPM_PCIE_INTR_SLV_PCIE_TIMEOUT BIT(28)
> #define XILINX_CPM_PCIE_IDRN_SHIFT 16
>
> /* Root Port Error FIFO Read Register definitions */ @@ -75,36 +103,37 @@
> * @reg_base: Bridge Register Base
> * @cpm_base: CPM System Level Control and Status Register(SLCR) Base
> * @dev: Device pointer
> - * @leg_domain: Legacy IRQ domain pointer
> + * @intx_domain: Legacy IRQ domain pointer
> * @cfg: Holds mappings of config space window
> - * @irq_misc: Legacy and error interrupt number
> - * @leg_mask_lock: lock for legacy interrupts
> + * @irq: INTx and error interrupt number
> + * @lock: lock protecting shared register access
> */
> struct xilinx_cpm_pcie_port {
> - void __iomem *reg_base;
> - void __iomem *cpm_base;
> - struct device *dev;
> - struct irq_domain *leg_domain;
> - struct pci_config_window *cfg;
> - int irq_misc;
> - raw_spinlock_t leg_mask_lock;
> + void __iomem *reg_base;
> + void __iomem *cpm_base;
> + struct device *dev;
> + struct irq_domain *intx_domain;
> + struct irq_domain *cpm_domain;
> + struct pci_config_window *cfg;
> + int irq;
> + raw_spinlock_t lock;
> };
>
> static inline u32 pcie_read(struct xilinx_cpm_pcie_port *port, u32 reg)
> {
> - return readl(port->reg_base + reg);
> + return readl_relaxed(port->reg_base + reg);
> }
>
> static inline void pcie_write(struct xilinx_cpm_pcie_port *port,
> u32 val, u32 reg)
> {
> - writel(val, port->reg_base + reg);
> + writel_relaxed(val, port->reg_base + reg);
> }
>
> static inline bool cpm_pcie_link_up(struct xilinx_cpm_pcie_port *port)
> {
> return (pcie_read(port, XILINX_CPM_PCIE_REG_PSCR) &
> - XILINX_CPM_PCIE_REG_PSCR_LNKUP) ? 1 : 0;
> + XILINX_CPM_PCIE_REG_PSCR_LNKUP);
> }
>
> /**
> @@ -125,44 +154,56 @@ static void cpm_pcie_clear_err_interrupts(struct
> xilinx_cpm_pcie_port *port)
>
> static void xilinx_cpm_mask_leg_irq(struct irq_data *data)
> {
> - struct irq_desc *desc = irq_to_desc(data->irq);
> - struct xilinx_cpm_pcie_port *port;
> + struct xilinx_cpm_pcie_port *port =
> irq_data_get_irq_chip_data(data);
> unsigned long flags;
> u32 mask;
> u32 val;
>
> - port = irq_desc_get_chip_data(desc);
> - mask = (1 << data->hwirq) << XILINX_CPM_PCIE_IDRN_SHIFT;
> - raw_spin_lock_irqsave(&port->leg_mask_lock, flags);
> + mask = BIT(data->hwirq + XILINX_CPM_PCIE_IDRN_SHIFT);
> + raw_spin_lock_irqsave(&port->lock, flags);
> val = pcie_read(port, XILINX_CPM_PCIE_REG_IDRN_MASK);
> pcie_write(port, (val & (~mask)),
> XILINX_CPM_PCIE_REG_IDRN_MASK);
> - raw_spin_unlock_irqrestore(&port->leg_mask_lock, flags);
> + raw_spin_unlock_irqrestore(&port->lock, flags);
> }
>
> static void xilinx_cpm_unmask_leg_irq(struct irq_data *data)
> {
> - struct irq_desc *desc = irq_to_desc(data->irq);
> - struct xilinx_cpm_pcie_port *port;
> + struct xilinx_cpm_pcie_port *port =
> irq_data_get_irq_chip_data(data);
> unsigned long flags;
> u32 mask;
> u32 val;
>
> - port = irq_desc_get_chip_data(desc);
> - mask = (1 << data->hwirq) << XILINX_CPM_PCIE_IDRN_SHIFT;
> - raw_spin_lock_irqsave(&port->leg_mask_lock, flags);
> + mask = BIT(data->hwirq + XILINX_CPM_PCIE_IDRN_SHIFT);
> + raw_spin_lock_irqsave(&port->lock, flags);
> val = pcie_read(port, XILINX_CPM_PCIE_REG_IDRN_MASK);
> pcie_write(port, (val | mask), XILINX_CPM_PCIE_REG_IDRN_MASK);
> - raw_spin_unlock_irqrestore(&port->leg_mask_lock, flags);
> + raw_spin_unlock_irqrestore(&port->lock, flags);
> }
>
> static struct irq_chip xilinx_cpm_leg_irq_chip = {
> - .name = "xilinx_cpm_pcie:legacy",
> - .irq_enable = xilinx_cpm_unmask_leg_irq,
> - .irq_disable = xilinx_cpm_mask_leg_irq,
> - .irq_mask = xilinx_cpm_mask_leg_irq,
> - .irq_unmask = xilinx_cpm_unmask_leg_irq,
> + .name = "INTx",
> + .irq_mask = xilinx_cpm_mask_leg_irq,
> + .irq_unmask = xilinx_cpm_unmask_leg_irq,
> };
>
> +static void xilinx_cpm_pcie_intx_flow(struct irq_desc *desc) {
> + struct xilinx_cpm_pcie_port *port =
> irq_desc_get_handler_data(desc);
> + struct irq_chip *chip = irq_desc_get_chip(desc);
> + unsigned long val;
> + int i;
> +
> + chained_irq_enter(chip, desc);
> +
> + val = FIELD_GET(XILINX_CPM_PCIE_IDRN_MASK,
> + pcie_read(port, XILINX_CPM_PCIE_REG_IDRN));
> +
> + for_each_set_bit(i, &val, PCI_NUM_INTX)
> + generic_handle_irq(irq_find_mapping(port->intx_domain, i));
> +
> + chained_irq_exit(chip, desc);
> +}
> +
> /**
> * xilinx_cpm_pcie_intx_map - Set the handler for the INTx and mark IRQ as
> valid
> * @domain: IRQ domain
> @@ -187,111 +228,130 @@ static const struct irq_domain_ops
> intx_domain_ops = {
> .map = xilinx_cpm_pcie_intx_map,
> };
>
> -/**
> - * xilinx_cpm_pcie_intr_handler - Interrupt Service Handler
> - * @irq: IRQ number
> - * @data: PCIe port information
> - *
> - * Return: IRQ_HANDLED on success and IRQ_NONE on failure
> - */
> -static irqreturn_t xilinx_cpm_pcie_intr_handler(int irq, void *data)
> +static void xilinx_cpm_mask_event_irq(struct irq_data *d)
> {
> - struct xilinx_cpm_pcie_port *port = data;
> - struct device *dev = port->dev;
> - u32 val, mask, status, bit;
> - unsigned long intr_val;
> -
> - /* Read interrupt decode and mask registers */
> - val = pcie_read(port, XILINX_CPM_PCIE_REG_IDR);
> - mask = pcie_read(port, XILINX_CPM_PCIE_REG_IMR);
> -
> - status = val & mask;
> - if (!status)
> - return IRQ_NONE;
> -
> - if (status & XILINX_CPM_PCIE_INTR_LINK_DOWN)
> - dev_warn(dev, "Link Down\n");
> -
> - if (status & XILINX_CPM_PCIE_INTR_HOT_RESET)
> - dev_info(dev, "Hot reset\n");
> -
> - if (status & XILINX_CPM_PCIE_INTR_CFG_TIMEOUT)
> - dev_warn(dev, "ECAM access timeout\n");
> -
> - if (status & XILINX_CPM_PCIE_INTR_CORRECTABLE) {
> - dev_warn(dev, "Correctable error message\n");
> - cpm_pcie_clear_err_interrupts(port);
> - }
> -
> - if (status & XILINX_CPM_PCIE_INTR_NONFATAL) {
> - dev_warn(dev, "Non fatal error message\n");
> - cpm_pcie_clear_err_interrupts(port);
> - }
> -
> - if (status & XILINX_CPM_PCIE_INTR_FATAL) {
> - dev_warn(dev, "Fatal error message\n");
> - cpm_pcie_clear_err_interrupts(port);
> - }
> -
> - if (status & XILINX_CPM_PCIE_INTR_INTX) {
> - /* Handle INTx Interrupt */
> - intr_val = pcie_read(port, XILINX_CPM_PCIE_REG_IDRN);
> - intr_val = intr_val >> XILINX_CPM_PCIE_IDRN_SHIFT;
> -
> - for_each_set_bit(bit, &intr_val, PCI_NUM_INTX)
> - generic_handle_irq(irq_find_mapping(port-
> >leg_domain,
> - bit));
> - }
> -
> - if (status & XILINX_CPM_PCIE_INTR_SLV_UNSUPP)
> - dev_warn(dev, "Slave unsupported request\n");
>
> - if (status & XILINX_CPM_PCIE_INTR_SLV_UNEXP)
> - dev_warn(dev, "Slave unexpected completion\n");
> + struct xilinx_cpm_pcie_port *port = irq_data_get_irq_chip_data(d);
> + u32 val;
>
> - if (status & XILINX_CPM_PCIE_INTR_SLV_COMPL)
> - dev_warn(dev, "Slave completion timeout\n");
> + raw_spin_lock(&port->lock);
> + val = pcie_read(port, XILINX_CPM_PCIE_REG_IMR);
> + val &= ~d->hwirq;
> + pcie_write(port, val, XILINX_CPM_PCIE_REG_IMR);
> + raw_spin_unlock(&port->lock);
> +}
>
> - if (status & XILINX_CPM_PCIE_INTR_SLV_ERRP)
> - dev_warn(dev, "Slave Error Poison\n");
> +static void xilinx_cpm_unmask_event_irq(struct irq_data *d) {
> + struct xilinx_cpm_pcie_port *port = irq_data_get_irq_chip_data(d);
> + u32 val;
>
> - if (status & XILINX_CPM_PCIE_INTR_SLV_CMPABT)
> - dev_warn(dev, "Slave Completer Abort\n");
> + raw_spin_lock(&port->lock);
> + val = pcie_read(port, XILINX_CPM_PCIE_REG_IMR);
> + val |= d->hwirq;
> + pcie_write(port, val, XILINX_CPM_PCIE_REG_IMR);
> + raw_spin_unlock(&port->lock);
> +}
>
> - if (status & XILINX_CPM_PCIE_INTR_SLV_ILLBUR)
> - dev_warn(dev, "Slave Illegal Burst\n");
> +static struct irq_chip xilinx_cpm_event_irq_chip = {
> + .name = "RC-Event",
> + .irq_mask = xilinx_cpm_mask_event_irq,
> + .irq_unmask = xilinx_cpm_unmask_event_irq,
> +};
>
> - if (status & XILINX_CPM_PCIE_INTR_MST_DECERR)
> - dev_warn(dev, "Master decode error\n");
> +static int xilinx_cpm_pcie_event_map(struct irq_domain *domain,
> + unsigned int irq, irq_hw_number_t hwirq)
> {
> + irq_set_chip_and_handler(irq, &xilinx_cpm_event_irq_chip,
> + handle_level_irq);
> + irq_set_chip_data(irq, domain->host_data);
> + irq_set_status_flags(irq, IRQ_LEVEL);
>
> - if (status & XILINX_CPM_PCIE_INTR_MST_SLVERR)
> - dev_warn(dev, "Master slave error\n");
> + return 0;
> +}
>
> - if (status & XILINX_CPM_PCIE_INTR_CFG_PCIE_TIMEOUT)
> - dev_warn(dev, "PCIe ECAM access timeout\n");
> +static const struct irq_domain_ops event_domain_ops = {
> + .map = xilinx_cpm_pcie_event_map,
> +};
>
> - if (status & XILINX_CPM_PCIE_INTR_CFG_ERR_POISON)
> - dev_warn(dev, "ECAM poisoned completion received\n");
> +static void xilinx_cpm_pcie_event_flow(struct irq_desc *desc) {
> + struct xilinx_cpm_pcie_port *port =
> irq_desc_get_handler_data(desc);
> + struct irq_chip *chip = irq_desc_get_chip(desc);
> + unsigned long val;
> + int i;
>
> - if (status & XILINX_CPM_PCIE_INTR_PME_TO_ACK_RCVD)
> - dev_warn(dev, "PME_TO_ACK message received\n");
> + chained_irq_enter(chip, desc);
>
> - if (status & XILINX_CPM_PCIE_INTR_PM_PME_RCVD)
> - dev_warn(dev, "PM_PME message received\n");
> + val = pcie_read(port, XILINX_CPM_PCIE_REG_IDR);
> + val &= pcie_read(port, XILINX_CPM_PCIE_REG_IMR);
>
> - if (status & XILINX_CPM_PCIE_INTR_SLV_PCIE_TIMEOUT)
> - dev_warn(dev, "PCIe completion timeout received\n");
> + for_each_set_bit(i, &val, 32)
> + generic_handle_irq(irq_find_mapping(port->cpm_domain,
> i));
>
> /* Clear the Interrupt Decode register */
> - pcie_write(port, status, XILINX_CPM_PCIE_REG_IDR);
> + pcie_write(port, val, XILINX_CPM_PCIE_REG_IDR);
>
> /*
> * XILINX_CPM_PCIE_MISC_IR_STATUS register is mapped to
> * CPM SLCR block.
> */
> - val = readl(port->cpm_base + XILINX_CPM_PCIE_MISC_IR_STATUS);
> + val = readl_relaxed(port->cpm_base +
> XILINX_CPM_PCIE_MISC_IR_STATUS);
> if (val)
> - writel(val, port->cpm_base +
> XILINX_CPM_PCIE_MISC_IR_STATUS);
> + writel_relaxed(val, port->cpm_base +
> XILINX_CPM_PCIE_MISC_IR_STATUS);
> +
> + chained_irq_exit(chip, desc);
> +}
> +
> +#define _IC(x, s) \
> + [XILINX_CPM_PCIE_INTR_ ## x] = { __stringify(x), s }
> +
> +static const struct {
> + const char *sym;
> + const char *str;
> +} intr_cause[32] = {
> + _IC(LINK_DOWN, "Link Down"),
> + _IC(HOT_RESET, "Hot reset"),
> + _IC(CFG_TIMEOUT, "ECAM access timeout"),
> + _IC(CORRECTABLE, "Correctable error message"),
> + _IC(NONFATAL, "Non fatal error message"),
> + _IC(FATAL, "Fatal error message"),
> + _IC(SLV_UNSUPP, "Slave unsupported request"),
> + _IC(SLV_UNEXP, "Slave unexpected completion"),
> + _IC(SLV_COMPL, "Slave completion timeout"),
> + _IC(SLV_ERRP, "Slave Error Poison"),
> + _IC(SLV_CMPABT, "Slave Completer Abort"),
> + _IC(SLV_ILLBUR, "Slave Illegal Burst"),
> + _IC(MST_DECERR, "Master decode error"),
> + _IC(MST_SLVERR, "Master slave error"),
> + _IC(CFG_PCIE_TIMEOUT, "PCIe ECAM access timeout"),
> + _IC(CFG_ERR_POISON, "ECAM poisoned completion received"),
> + _IC(PME_TO_ACK_RCVD, "PME_TO_ACK message received"),
> + _IC(PM_PME_RCVD, "PM_PME message received"),
> + _IC(SLV_PCIE_TIMEOUT, "PCIe completion timeout received"),
> +};
> +
> +static irqreturn_t xilinx_cpm_pcie_intr_handler(int irq, void *dev_id)
> +{
> + struct xilinx_cpm_pcie_port *port = dev_id;
> + struct device *dev = port->dev;
> + struct irq_data *d;
> +
> + d = irq_domain_get_irq_data(port->cpm_domain, irq);
> +
> + switch(d->hwirq) {
> + case XILINX_CPM_PCIE_INTR_CORRECTABLE:
> + case XILINX_CPM_PCIE_INTR_NONFATAL:
> + case XILINX_CPM_PCIE_INTR_FATAL:
> + cpm_pcie_clear_err_interrupts(port);
> + fallthrough;
> +
> + default:
> + if (intr_cause[d->hwirq].str)
> + dev_warn(dev, "%s\n", intr_cause[d->hwirq].str);
> + else
> + dev_warn(dev, "Unknown interrupt\n");
> + }
>
> return IRQ_HANDLED;
> }
> @@ -315,17 +375,41 @@ static int xilinx_cpm_pcie_init_irq_domain(struct
> xilinx_cpm_pcie_port *port)
> return -EINVAL;
> }
>
> - port->leg_domain = irq_domain_add_linear(pcie_intc_node,
> PCI_NUM_INTX,
> + port->cpm_domain = irq_domain_add_linear(pcie_intc_node, 32,
> + &event_domain_ops,
> + port);
> + if (!port->cpm_domain)
> + goto out;
> +
> + irq_domain_update_bus_token(port->cpm_domain,
> DOMAIN_BUS_NEXUS);
> +
> + port->intx_domain = irq_domain_add_linear(pcie_intc_node,
> PCI_NUM_INTX,
> &intx_domain_ops,
> port);
> + if (!port->intx_domain)
> + goto out;
> +
> + irq_domain_update_bus_token(port->intx_domain,
> DOMAIN_BUS_WIRED);
> +
> of_node_put(pcie_intc_node);
> - if (!port->leg_domain) {
> - dev_err(dev, "Failed to get a INTx IRQ domain\n");
> - return -ENOMEM;
> - }
> + raw_spin_lock_init(&port->lock);
>
> - raw_spin_lock_init(&port->leg_mask_lock);
> return 0;
> +
> +out:
> + of_node_put(pcie_intc_node);
> + if (port->intx_domain) {
> + irq_domain_remove(port->intx_domain);
> + port->intx_domain = NULL;
> + }
> +
> + if (port->cpm_domain) {
> + irq_domain_remove(port->cpm_domain);
> + port->cpm_domain = NULL;
> + }
> +
> + dev_err(dev, "Failed to allocate IRQ domains\n");
> + return -ENOMEM;
> }
>
> /**
> @@ -348,12 +432,6 @@ static void xilinx_cpm_pcie_init_port(struct
> xilinx_cpm_pcie_port *port)
> XILINX_CPM_PCIE_IMR_ALL_MASK,
> XILINX_CPM_PCIE_REG_IDR);
>
> - /* Enable all interrupts */
> - pcie_write(port, XILINX_CPM_PCIE_IMR_ALL_MASK,
> - XILINX_CPM_PCIE_REG_IMR);
> - pcie_write(port, XILINX_CPM_PCIE_IDRN_MASK,
> - XILINX_CPM_PCIE_REG_IDRN_MASK);
> -
> /*
> * XILINX_CPM_PCIE_MISC_IR_ENABLE register is mapped to
> * CPM SLCR block.
> @@ -366,28 +444,45 @@ static void xilinx_cpm_pcie_init_port(struct
> xilinx_cpm_pcie_port *port)
> XILINX_CPM_PCIE_REG_RPSC);
> }
>
> -static int xilinx_cpm_request_misc_irq(struct xilinx_cpm_pcie_port
> *port)
> +static int xilinx_cpm_setup_irq(struct xilinx_cpm_pcie_port *port)
> {
> struct device *dev = port->dev;
> struct platform_device *pdev = to_platform_device(dev);
> - int err;
> + int i, irq;
>
> - port->irq_misc = platform_get_irq(pdev, 0);
> - if (port->irq_misc <= 0) {
> - dev_err(dev, "Unable to find misc IRQ line\n");
> - return port->irq_misc;
> + port->irq = platform_get_irq(pdev, 0);
> + if (port->irq < 0) {
> + dev_err(dev, "Unable to find IRQ line\n");
> + return port->irq;
> }
>
> - err = devm_request_irq(dev, port->irq_misc,
> - xilinx_cpm_pcie_intr_handler,
> - IRQF_SHARED | IRQF_NO_THREAD,
> - "xilinx-pcie", port);
> - if (err) {
> - dev_err(dev, "unable to request misc IRQ line %d\n",
> - port->irq_misc);
> - return err;
> + for (i = 0; i < ARRAY_SIZE(intr_cause); i++) {
> + int err;
> +
> + if (!intr_cause[i].str)
> + continue;
> +
> + irq = irq_create_mapping(port->cpm_domain, i);
> + if (WARN_ON(irq <= 0))
> + return -ENXIO;
> +
> + err = devm_request_irq(dev, irq,
> xilinx_cpm_pcie_intr_handler,
> + 0, intr_cause[i].sym, port);
> + if (WARN_ON(err))
> + return err;
> }
>
> + irq = irq_create_mapping(port->cpm_domain,
> XILINX_CPM_PCIE_INTR_INTX);
> + if (WARN_ON(irq <= 0))
> + return -ENXIO;
> +
> + /* Plug the INTx chained handler */
> + irq_set_chained_handler_and_data(irq, xilinx_cpm_pcie_intx_flow,
> port);
> +
> + /* Plug the main event chained handler */
> + irq_set_chained_handler_and_data(port->irq,
> xilinx_cpm_pcie_event_flow,
> + port);
> +
> return 0;
> }
>
> @@ -422,7 +517,7 @@ static int xilinx_cpm_pcie_parse_dt(struct
> xilinx_cpm_pcie_port *port,
> if (IS_ERR(port->cpm_base))
> return PTR_ERR(port->cpm_base);
>
> - err = xilinx_cpm_request_misc_irq(port);
> + err = xilinx_cpm_setup_irq(port);
> if (err)
> return err;
>
> @@ -481,8 +576,10 @@ static int xilinx_cpm_pcie_probe(struct
> platform_device *pdev)
>
> err = pci_host_probe(bridge);
> if (err < 0) {
> - irq_domain_remove(port->leg_domain);
> - devm_free_irq(dev, port->irq_misc, port);
> + if (port->intx_domain)
> + irq_domain_remove(port->intx_domain);
> + if (port->cpm_domain)
> + irq_domain_remove(port->cpm_domain);
> return err;
> }
>
> --
> 2.26.2
>
>
> --
> Jazz is not dead. It just smells funny...

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