[PATCH v4] pcie: Add Xilinx PCIe Host Bridge IP driver
Bjorn Helgaas
bhelgaas at google.com
Wed Jul 16 10:38:24 PDT 2014
On Thu, Jul 03, 2014 at 09:57:34AM +0530, Srikanth Thokala wrote:
> This is the driver for Xilinx AXI PCIe Host Bridge Soft IP
>
> Signed-off-by: Srikanth Thokala <sthokal at xilinx.com>
> ---
> Changes in v4:
> - Regarding the comments to separate ECAM functionality,
> I have sent a separate patch and it is decided to implement
> it later. The patch is here,
> https://lkml.org/lkml/2014/5/18/54
> - Fixed issue with adding configuration bus resource.
> - Moved the logic for setting up bus resources to probe() from
> pcie_setup().
> - Instead of mapping all the MSI interrupts in the probe, changed
> to map only when a MSI is requested.
> - Earlier, the implementation of legacy and MSI interrupts init-
> is mutually exclusive, now changed to have the legacy interrupts
> init always and MSI interrupt init based on CONFIG_PCI_MSI flag.
> - Regarding the MSI generic implementation comment, I will plan to
> do on top of this driver patch.
> - Rebased on 3.16-rc2.
> - Fixed other minor comments.
> - Thanks Arnd and Bjorn for the review.
>
> Changes in v3:
> - Rebased on v3.15.0-rc1
> - Added support for interrupt-map DT functionality.
> - Removed map_irq() wrapper, instead using of_irq_parse_and_map_pci().
> - Modified resource mapping logic as per the series
> "PCI: ARM: add support for generic PCI host controller"
> - Modified devicetree binding documentation to update with interrupt-
> map properties.
> - Use devm calls wherever applicable.
> - Fixed minor comments from Jason
> - Thanks Jason for the review and suggestions.
>
> Changes in v2:
> - Rebased on v3.14.0-rc8
> - Removed IP specific DT properties like include-rc, axibar-num etc.,
> as suggested by Jason and Bjorn, Thanks
> ---
> .../devicetree/bindings/pci/xilinx-pcie.txt | 62 ++
> drivers/pci/host/Kconfig | 7 +
> drivers/pci/host/Makefile | 1 +
> drivers/pci/host/pci-xilinx.c | 1027 ++++++++++++++++++++
> 4 files changed, 1097 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/pci/xilinx-pcie.txt
> create mode 100644 drivers/pci/host/pci-xilinx.c
I see I forgot to ask for a MAINTAINERS entry for this driver. Can
you add one?
I'd also like an ack from Arnd or another devicetree person for the
binding.
I have a few minor comments below.
> diff --git a/Documentation/devicetree/bindings/pci/xilinx-pcie.txt b/Documentation/devicetree/bindings/pci/xilinx-pcie.txt
> new file mode 100644
> index 0000000..3e2c88d
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/pci/xilinx-pcie.txt
> @@ -0,0 +1,62 @@
> +* Xilinx AXI PCIe Root Port Bridge DT description
> +
> +Required properties:
> +- #address-cells: Address representation for root ports, set to <3>
> +- #size-cells: Size representation for root ports, set to <2>
> +- #interrupt-cells: specifies the number of cells needed to encode an
> + interrupt source. The value must be 1.
> +- compatible: Should contain "xlnx,axi-pcie-host-1.00.a"
> +- reg: Should contain AXI PCIe registers location and length
> +- device_type: must be "pci"
> +- interrupts: Should contain AXI PCIe interrupt
> +- interrupt-map-mask,
> + interrupt-map: standard PCI properties to define the mapping of the
> + PCI interface to interrupt numbers.
> +- ranges: ranges for the PCI memory regions (I/O space region is not
> + supported by hardware)
> + Please refer to the standard PCI bus binding document for a more
> + detailed explanation
> +
> +Optional properties:
> +- bus-range: PCI bus numbers covered
> +
> +Interrupt controller child node
> ++++++++++++++++++++++++++++++++
> +Required properties:
> +- interrupt-controller: identifies the node as an interrupt controller
> +- #address-cells: specifies the number of cells needed to encode an
> + address. The value must be 0.
> +- #interrupt-cells: specifies the number of cells needed to encode an
> + interrupt source. The value must be 1.
> +
> +NOTE:
> +The core provides a single interrupt for both INTx/MSI messages. So,
> +created a interrupt controller node to support 'interrupt-map' DT
> +functionality. The driver will create an IRQ domain for this map, decode
> +the four INTx interrupts in ISR and route them to this domain.
> +
> +
> +Example:
> +++++++++
> +
> + pci_express: axi-pcie at 50000000 {
> + #address-cells = <3>;
> + #size-cells = <2>;
> + #interrupt-cells = <1>;
> + compatible = "xlnx,axi-pcie-host-1.00.a";
> + reg = < 0x50000000 0x10000000 >;
> + device_type = "pci";
> + interrupts = < 0 52 4 >;
> + interrupt-map-mask = <0 0 0 7>;
> + interrupt-map = <0 0 0 1 &pcie_intc 1>,
> + <0 0 0 2 &pcie_intc 2>,
> + <0 0 0 3 &pcie_intc 3>,
> + <0 0 0 4 &pcie_intc 4>;
> + ranges = < 0x02000000 0 0x60000000 0x60000000 0 0x10000000 >;
> +
> + pcie_intc: interrupt-controller {
> + interrupt-controller;
> + #address-cells = <0>;
> + #interrupt-cells = <1>;
> + }
> + };
> diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig
> index 21df477..afedcde 100644
> --- a/drivers/pci/host/Kconfig
> +++ b/drivers/pci/host/Kconfig
> @@ -46,4 +46,11 @@ config PCI_HOST_GENERIC
> Say Y here if you want to support a simple generic PCI host
> controller, such as the one emulated by kvmtool.
>
> +config PCI_XILINX
> + bool "Xilinx AXI PCIe host bridge support"
> + depends on ARCH_ZYNQ
> + help
> + Say 'Y' here if you want kernel to support the Xilinx AXI PCIe
> + Host Bridge driver.
> +
> endmenu
> diff --git a/drivers/pci/host/Makefile b/drivers/pci/host/Makefile
> index 611ba4b..68dfd06 100644
> --- a/drivers/pci/host/Makefile
> +++ b/drivers/pci/host/Makefile
> @@ -6,3 +6,4 @@ obj-$(CONFIG_PCI_TEGRA) += pci-tegra.o
> obj-$(CONFIG_PCI_RCAR_GEN2) += pci-rcar-gen2.o
> obj-$(CONFIG_PCI_RCAR_GEN2_PCIE) += pcie-rcar.o
> obj-$(CONFIG_PCI_HOST_GENERIC) += pci-host-generic.o
> +obj-$(CONFIG_PCI_XILINX) += pci-xilinx.o
> diff --git a/drivers/pci/host/pci-xilinx.c b/drivers/pci/host/pci-xilinx.c
> new file mode 100644
> index 0000000..57d59e7
> --- /dev/null
> +++ b/drivers/pci/host/pci-xilinx.c
> @@ -0,0 +1,1027 @@
> +/*
> + * PCIe host controller driver for Xilinx AXI PCIe Bridge
> + *
> + * Copyright (c) 2012 - 2014 Xilinx, Inc.
> + *
> + * Based on the Tegra PCIe driver
> + *
> + * Bits taken from Synopsys Designware Host controller driver and
> + * ARM PCI Host generic driver.
> + *
> + * This program is free software: you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation, either version 2 of the License, or
> + * (at your option) any later version.
> + */
> +
> +#include <linux/interrupt.h>
> +#include <linux/irq.h>
> +#include <linux/irqdomain.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/msi.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>
> +
> +/* Register definitions */
> +#define XILINX_PCIE_REG_VSECC 0x00000128
> +#define XILINX_PCIE_REG_VSECH 0x0000012c
> +#define XILINX_PCIE_REG_BIR 0x00000130
> +#define XILINX_PCIE_REG_BSCR 0x00000134
> +#define XILINX_PCIE_REG_IDR 0x00000138
> +#define XILINX_PCIE_REG_IMR 0x0000013c
> +#define XILINX_PCIE_REG_BLR 0x00000140
> +#define XILINX_PCIE_REG_PSCR 0x00000144
> +#define XILINX_PCIE_REG_RPSC 0x00000148
> +#define XILINX_PCIE_REG_MSIBASE1 0x0000014c
> +#define XILINX_PCIE_REG_MSIBASE2 0x00000150
> +#define XILINX_PCIE_REG_RPEFR 0x00000154
> +#define XILINX_PCIE_REG_RPIFR1 0x00000158
> +#define XILINX_PCIE_REG_RPIFR2 0x0000015c
> +#define XILINX_PCIE_REG_VSECC2 0x00000200
> +#define XILINX_PCIE_REG_VSECH2 0x00000204
> +
> +/* Interrupt registers definitions */
> +#define XILINX_PCIE_INTR_LINK_DOWN BIT(0)
> +#define XILINX_PCIE_INTR_ECRC_ERR BIT(1)
> +#define XILINX_PCIE_INTR_STR_ERR BIT(2)
> +#define XILINX_PCIE_INTR_HOT_RESET BIT(3)
> +#define XILINX_PCIE_INTR_CFG_COMPL GENMASK(7, 5)
> +#define XILINX_PCIE_INTR_CFG_TIMEOUT BIT(8)
> +#define XILINX_PCIE_INTR_CORRECTABLE BIT(9)
> +#define XILINX_PCIE_INTR_NONFATAL BIT(10)
> +#define XILINX_PCIE_INTR_FATAL BIT(11)
> +#define XILINX_PCIE_INTR_INTX BIT(16)
> +#define XILINX_PCIE_INTR_MSI BIT(17)
> +#define XILINX_PCIE_INTR_SLV_UNSUPP BIT(20)
> +#define XILINX_PCIE_INTR_SLV_UNEXP BIT(21)
> +#define XILINX_PCIE_INTR_SLV_COMPL BIT(22)
> +#define XILINX_PCIE_INTR_SLV_ERRP BIT(23)
> +#define XILINX_PCIE_INTR_SLV_CMPABT BIT(24)
> +#define XILINX_PCIE_INTR_SLV_ILLBUR BIT(25)
> +#define XILINX_PCIE_INTR_MST_DECERR BIT(26)
> +#define XILINX_PCIE_INTR_MST_SLVERR BIT(27)
> +#define XILINX_PCIE_INTR_MST_ERRP BIT(28)
> +#define XILINX_PCIE_IMR_ALL_MASK 0x1FF30FED
> +#define XILINX_PCIE_IDR_ALL_MASK 0xFFFFFFFF
> +
> +/* Root Port Error FIFO Read Register definitions */
> +#define XILINX_PCIE_RPEFR_ERR_VALID BIT(18)
> +#define XILINX_PCIE_RPEFR_REQ_ID GENMASK(15, 0)
> +#define XILINX_PCIE_RPEFR_ALL_MASK 0xFFFFFFFF
> +
> +/* Root Port Interrupt FIFO Read Register 1 definitions */
> +#define XILINX_PCIE_RPIFR1_INTR_VALID BIT(31)
> +#define XILINX_PCIE_RPIFR1_MSI_INTR BIT(30)
> +#define XILINX_PCIE_RPIFR1_INTR_ASSRT BIT(29)
> +#define XILINX_PCIE_RPIFR1_INTR_MASK GENMASK(28, 27)
> +#define XILINX_PCIE_RPIFR1_MSI_ADR_MASK GENMASK(26, 16)
> +#define XILINX_PCIE_RPIFR1_ALL_MASK 0xFFFFFFFF
> +#define XILINX_PCIE_RPIFR1_INTR_SHIFT 27
> +#define XILINX_PCIE_RPIFR1_MSI_ADR_SHIFT 16
> +
> +/* Bridge Info Register definitions */
> +#define XILINX_PCIE_BIR_ECAM_SZ_MASK GENMASK(18, 16)
> +#define XILINX_PCIE_BIR_ECAM_SZ_SHIFT 16
> +
> +/* Root Port Interrupt FIFO Read Register 2 definitions */
> +#define XILINX_PCIE_RPIFR2_MSG_DATA GENMASK(15, 0)
> +
> +/* Root Port Status/control Register definitions */
> +#define XILINX_PCIE_REG_RPSC_BEN BIT(0)
> +
> +/* Phy Status/Control Register definitions */
> +#define XILINX_PCIE_REG_PSCR_LNKUP BIT(11)
> +
> +/* ECAM definitions */
> +#define ECAM_BUS_NUM_SHIFT 20
> +#define ECAM_DEV_NUM_SHIFT 12
> +
> +/* PCI Configuration space Bus Number Register definitions */
> +#define PCI_SECONDARY_BUS_NUM_SHIFT 8
> +#define PCI_SUBORDINATE_BUS_NUM_SHIFT 16
> +#define PCI_LATENCY_TIMER_MASK GENMASK(31, 24)
These three #defines aren't used; can you remove them? (If you need
them someday, you should either try to use generic definitions from
include/uapi/linux/pci_regs.h, or if they're Xilinx-specific, rename
them so they look Xilinx-specific rather than generic.
> +
> +/* Number of MSI IRQs */
> +#define XILINX_NUM_MSI_IRQS 128
> +
> +/* Number of Memory Resources */
> +#define XILINX_MAX_NUM_RESOURCES 3
> +
> +/**
> + * struct xilinx_pcie_port - PCIe port information
> + * @reg_base: IO Mapped Register Base
> + * @irq: Interrupt number
> + * @msi_pages: MSI pages
> + * @root_busno: Root Bus number
> + * @link_up: Link status flag
> + * @dev: Device pointer
> + * @irq_domain: IRQ domain pointer
> + * @bus_range: Bus range
> + * @resources: Bus Resources
> + */
> +struct xilinx_pcie_port {
> + void __iomem *reg_base;
> + u32 irq;
> + unsigned long msi_pages;
> + u8 root_busno;
> + bool link_up;
> + struct device *dev;
> + struct irq_domain *irq_domain;
> + struct resource bus_range;
> + struct list_head resources;
> +};
> +
> +static DECLARE_BITMAP(msi_irq_in_use, XILINX_NUM_MSI_IRQS);
> +
> +static inline struct xilinx_pcie_port *sys_to_pcie(struct pci_sys_data *sys)
> +{
> + return sys->private_data;
> +}
> +
> +static inline u32 pcie_read(struct xilinx_pcie_port *port, u32 reg)
> +{
> + return readl(port->reg_base + reg);
> +}
> +
> +static inline void pcie_write(struct xilinx_pcie_port *port,
> + u32 val, u32 reg)
> +{
> + writel(val, port->reg_base + reg);
> +}
> +
> +static inline bool xilinx_pcie_is_link_up(struct xilinx_pcie_port *port)
Bool function names should be statements or properties, not questions,
since a statement can be true or false but a question cannot. For
example, in this case, "xilinx_pcie_link_up()" or
"xilinx_pcie_link_is_up()" would read better.
> +{
> + return (pcie_read(port, XILINX_PCIE_REG_PSCR) &
> + XILINX_PCIE_REG_PSCR_LNKUP) ? 1 : 0;
> +}
> +
> +/**
> + * xilinx_pcie_clear_err_interrupts - Clear Error Interrupts
> + * @port: PCIe port information
> + */
> +static inline void
> +xilinx_pcie_clear_err_interrupts(struct xilinx_pcie_port *port)
Put the signature all on one line. It probably doesn't need to be
inline (we're making a couple register accesses, so speed isn't a
concern), and removing that will make it fit.
> +{
> + u32 val = pcie_read(port, XILINX_PCIE_REG_RPEFR);
> +
> + if (val & XILINX_PCIE_RPEFR_ERR_VALID) {
> + dev_dbg(port->dev, "Requester ID %d\n",
> + val & XILINX_PCIE_RPEFR_REQ_ID);
> + pcie_write(port, XILINX_PCIE_RPEFR_ALL_MASK,
> + XILINX_PCIE_REG_RPEFR);
> + }
> +}
> +
> +/**
> + * xilinx_pcie_verify_config - Verify configuration
> + * @bus: PCI Bus structure
> + * @devfn: device/function
> + *
> + * Return: 0 on success and error value for invalid configuration
> + */
> +static int xilinx_pcie_verify_config(struct pci_bus *bus,
> + unsigned int devfn)
"verify_config" is not a great function name because it doesn't give a
good clue about what the return value is. If you make it boolean and
name it, e.g., xilinx_pcie_valid_device(), then it's obvious.
> +{
> + struct xilinx_pcie_port *port = sys_to_pcie(bus->sysdata);
> +
> + /* Check if link is up when trying to access downstream ports */
> + if (bus->number != port->root_busno)
> + if (!xilinx_pcie_is_link_up(port))
> + return -EINVAL;
> +
> + /* Only one device down on each root port */
> + if (bus->number == port->root_busno && devfn > 0)
> + return -EINVAL;
> +
> + /*
> + * Do not read more than one device on the bus directly attached
> + * to RC.
> + */
> + if (bus->primary == port->root_busno && devfn > 0)
> + return -EINVAL;
> +
> + return 0;
> +}
> +
> +/**
> + * xilinx_pcie_get_config_base - Get configuration base
> + * @bus: PCI Bus structure
> + * @devfn: Device/function
> + * @where: Offset from base
> + *
> + * Return: Base address of the configuration space needed to be
> + * accessed.
> + */
> +static void __iomem *xilinx_pcie_get_config_base(struct pci_bus *bus,
> + unsigned int devfn,
> + int where)
"xilinx_pcie_config_base()" would be sufficient. We use "get" as a
clue that we're acquiring a reference (obviously not an issue here,
but I think the "get" in this function name is still a bit redundant.)
> +{
> + struct xilinx_pcie_port *port = sys_to_pcie(bus->sysdata);
> + int relbus;
> +
> + relbus = (bus->number << ECAM_BUS_NUM_SHIFT) |
> + (devfn << ECAM_DEV_NUM_SHIFT);
> +
> + return port->reg_base + relbus + where;
> +}
> +
> +/**
> + * xilinx_pcie_read_config - Read configuration space
> + * @bus: PCI Bus structure
> + * @devfn: Device/function
> + * @where: Offset from base
> + * @size: Byte/word/dword
> + * @val: Value to be read
> + *
> + * Return: PCIBIOS_SUCCESSFUL on success
> + * EINVAL/PCIBIOS_DEVICE_NOT_FOUND/PCIBIOS_BAD_REGISTER_NUMBER
> + * on failure.
> + */
> +static int xilinx_pcie_read_config(struct pci_bus *bus,
> + unsigned int devfn, int where,
> + int size, u32 *val)
> +{
> + struct xilinx_pcie_port *port = sys_to_pcie(bus->sysdata);
> + void __iomem *addr;
> +
> + if (!port) {
> + BUG();
> + return -EINVAL;
> + }
I don't think you need to test "port" for NULL here. And I don't
think callers will be prepared for -EINVAL anyway; they'll be
expecting PCIBIOS_* values.
> + if (xilinx_pcie_verify_config(bus, devfn)) {
> + *val = 0xFFFFFFFF;
> + return PCIBIOS_DEVICE_NOT_FOUND;
> + }
> +
> + addr = xilinx_pcie_get_config_base(bus, devfn, where);
> +
> + switch (size) {
> + case 1:
> + *val = readb(addr);
> + break;
> + case 2:
> + *val = readw(addr);
> + break;
> + default:
> + *val = readl(addr);
> + break;
> + }
> +
> + return PCIBIOS_SUCCESSFUL;
> +}
> +
> +/**
> + * xilinx_pcie_write_config - Write configuration space
> + * @bus: PCI Bus structure
> + * @devfn: Device/function
> + * @where: Offset from base
> + * @size: Byte/word/dword
> + * @val: Value to be written to device
> + *
> + * Return: PCIBIOS_SUCCESSFUL on success,
> + * EINVAL/PCIBIOS_DEVICE_NOT_FOUND/PCIBIOS_BAD_REGISTER_NUMBER
> + * on failure.
> + */
> +static int xilinx_pcie_write_config(struct pci_bus *bus,
> + unsigned int devfn, int where,
> + int size, u32 val)
> +{
> + struct xilinx_pcie_port *port = sys_to_pcie(bus->sysdata);
> + void __iomem *addr;
> +
> + if (!port) {
> + BUG();
> + return -EINVAL;
> + }
I don't think this test is necessary.
> + if (xilinx_pcie_verify_config(bus, devfn))
> + return PCIBIOS_DEVICE_NOT_FOUND;
> +
> + addr = xilinx_pcie_get_config_base(bus, devfn, where);
> +
> + switch (size) {
> + case 1:
> + writeb(val, addr);
> + break;
> + case 2:
> + writew(val, addr);
> + break;
> + default:
> + writel(val, addr);
> + break;
> + }
> +
> + return PCIBIOS_SUCCESSFUL;
> +}
> +
> +/* PCIe operations */
> +static struct pci_ops xilinx_pcie_ops = {
> + .read = xilinx_pcie_read_config,
> + .write = xilinx_pcie_write_config,
> +};
> +
> +/* MSI functions */
> +
> +/**
> + * xilinx_pcie_destroy_msi - Free MSI number
> + * @irq: IRQ to be freed
> + */
> +static void xilinx_pcie_destroy_msi(unsigned int irq)
> +{
> + struct irq_desc *desc;
> + struct msi_desc *msi;
> + struct xilinx_pcie_port *port;
> +
> + desc = irq_to_desc(irq);
> + msi = irq_desc_get_msi_desc(desc);
> + port = sys_to_pcie(msi->dev->bus->sysdata);
> + if (!port) {
> + BUG();
> + return;
> + }
Or this one.
> + if (!test_bit(irq, msi_irq_in_use))
> + dev_err(port->dev, "Trying to free unused MSI#%d\n", irq);
> + else
> + clear_bit(irq, msi_irq_in_use);
> +}
> +
> +/**
> + * xilinx_pcie_assign_msi - Allocate MSI number
> + * @port: PCIe port structure
> + *
> + * Return: A valid IRQ on success and error value on failure.
> + */
> +static int xilinx_pcie_assign_msi(struct xilinx_pcie_port *port)
> +{
> + int pos;
> +
> + pos = find_first_zero_bit(msi_irq_in_use, XILINX_NUM_MSI_IRQS);
> + if (pos < XILINX_NUM_MSI_IRQS)
> + set_bit(pos, msi_irq_in_use);
> + else
> + return -ENOSPC;
> +
> + return pos;
> +}
> +
> +/**
> + * xilinx_msi_teardown_irq - Destroy the MSI
> + * @chip: MSI Chip descriptor
> + * @irq: MSI IRQ to destroy
> + */
> +static void xilinx_msi_teardown_irq(struct msi_chip *chip, unsigned int irq)
> +{
> + xilinx_pcie_destroy_msi(irq);
> +}
> +
> +/**
> + * xilinx_pcie_msi_setup_irq - Setup MSI request
> + * @chip: MSI chip pointer
> + * @pdev: PCIe device pointer
> + * @desc: MSI descriptor pointer
> + *
> + * Return: '0' on success and error value on failure
> + */
> +static int xilinx_pcie_msi_setup_irq(struct msi_chip *chip,
> + struct pci_dev *pdev,
> + struct msi_desc *desc)
> +{
> + struct xilinx_pcie_port *port = sys_to_pcie(pdev->bus->sysdata);
> + unsigned int irq;
> + int hwirq;
> + struct msi_msg msg;
> + phys_addr_t msg_addr;
> +
> + if (!port) {
> + BUG();
> + return -EINVAL;
> + }
Or this one.
> + hwirq = xilinx_pcie_assign_msi(port);
> + if (irq < 0)
> + return irq;
> +
> + irq = irq_create_mapping(port->irq_domain, hwirq);
> + if (!irq)
> + return -EINVAL;
> +
> + irq_set_msi_desc(irq, desc);
> +
> + msg_addr = virt_to_phys((void *)port->msi_pages);
> +
> + msg.address_hi = 0;
> + msg.address_lo = msg_addr;
> + msg.data = irq;
> +
> + write_msi_msg(irq, &msg);
> +
> + return 0;
> +}
> +
> +/* MSI Chip Descriptor */
> +static struct msi_chip xilinx_pcie_msi_chip = {
> + .setup_irq = xilinx_pcie_msi_setup_irq,
> + .teardown_irq = xilinx_msi_teardown_irq,
> +};
> +
> +/* HW Interrupt Chip Descriptor */
> +static struct irq_chip xilinx_msi_irq_chip = {
> + .name = "Xilinx PCIe MSI",
> + .irq_enable = unmask_msi_irq,
> + .irq_disable = mask_msi_irq,
> + .irq_mask = mask_msi_irq,
> + .irq_unmask = unmask_msi_irq,
> +};
> +
> +/**
> + * xilinx_pcie_msi_map - Set the handler for the MSI and mark IRQ as valid
> + * @domain: IRQ domain
> + * @irq: Virtual IRQ number
> + * @hwirq: HW interrupt number
> + *
> + * Return: Always returns 0.
> + */
> +static int xilinx_pcie_msi_map(struct irq_domain *domain, unsigned int irq,
> + irq_hw_number_t hwirq)
> +{
> + irq_set_chip_and_handler(irq, &xilinx_msi_irq_chip, handle_simple_irq);
> + irq_set_chip_data(irq, domain->host_data);
> + set_irq_flags(irq, IRQF_VALID);
> +
> + return 0;
> +}
> +
> +/* IRQ Domain operations */
> +static const struct irq_domain_ops msi_domain_ops = {
> + .map = xilinx_pcie_msi_map,
> +};
> +
> +/**
> + * xilinx_pcie_enable_msi - Enable MSI support
> + * @port: PCIe port information
> + */
> +static void xilinx_pcie_enable_msi(struct xilinx_pcie_port *port)
> +{
> + phys_addr_t msg_addr;
> +
> + port->msi_pages = __get_free_pages(GFP_KERNEL, 0);
> + msg_addr = virt_to_phys((void *)port->msi_pages);
> + pcie_write(port, 0x0, XILINX_PCIE_REG_MSIBASE1);
> + pcie_write(port, msg_addr, XILINX_PCIE_REG_MSIBASE2);
> +}
> +
> +/**
> + * xilinx_pcie_add_bus - Add MSI chip info to PCIe bus
> + * @bus: PCIe bus
> + */
> +static void xilinx_pcie_add_bus(struct pci_bus *bus)
> +{
> + if (IS_ENABLED(CONFIG_PCI_MSI)) {
Did you verify that this builds with both CONFIG_PCI_MSI=y and with it
unset?
> + struct xilinx_pcie_port *port = sys_to_pcie(bus->sysdata);
> +
> + if (!port)
> + return;
Unnecessary "port" test.
> + xilinx_pcie_msi_chip.dev = port->dev;
> + bus->msi = &xilinx_pcie_msi_chip;
> + }
> +}
> +
> +/* INTx Functions */
> +
> +/**
> + * xilinx_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_pcie_intx_map(struct irq_domain *domain, unsigned int irq,
> + irq_hw_number_t hwirq)
> +{
> + irq_set_chip_and_handler(irq, &dummy_irq_chip, handle_simple_irq);
> + irq_set_chip_data(irq, domain->host_data);
> + set_irq_flags(irq, IRQF_VALID);
> +
> + return 0;
> +}
> +
> +/* INTx IRQ Domain operations */
> +static const struct irq_domain_ops intx_domain_ops = {
> + .map = xilinx_pcie_intx_map,
> +};
> +
> +/* PCIe HW Functions */
> +
> +/**
> + * xilinx_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_pcie_intr_handler(int irq, void *data)
> +{
> + struct xilinx_pcie_port *port = (struct xilinx_pcie_port *)data;
> + u32 val, mask, status, msi_data;
> +
> + /* Read interrupt decode and mask registers */
> + val = pcie_read(port, XILINX_PCIE_REG_IDR);
> + mask = pcie_read(port, XILINX_PCIE_REG_IMR);
> +
> + status = val & mask;
> + if (!status)
> + return IRQ_NONE;
> +
> + if (status & XILINX_PCIE_INTR_LINK_DOWN)
> + dev_warn(port->dev, "Link Down\n");
> +
> + if (status & XILINX_PCIE_INTR_ECRC_ERR)
> + dev_warn(port->dev, "ECRC failed\n");
> +
> + if (status & XILINX_PCIE_INTR_STR_ERR)
> + dev_warn(port->dev, "Streaming error\n");
> +
> + if (status & XILINX_PCIE_INTR_HOT_RESET)
> + dev_info(port->dev, "Hot reset\n");
> +
> + if (status & XILINX_PCIE_INTR_CFG_TIMEOUT)
> + dev_warn(port->dev, "ECAM access timeout\n");
> +
> + if (status & XILINX_PCIE_INTR_CORRECTABLE) {
> + dev_warn(port->dev, "Correctable error message\n");
> + xilinx_pcie_clear_err_interrupts(port);
> + }
> +
> + if (status & XILINX_PCIE_INTR_NONFATAL) {
> + dev_warn(port->dev, "Non fatal error message\n");
> + xilinx_pcie_clear_err_interrupts(port);
> + }
> +
> + if (status & XILINX_PCIE_INTR_FATAL) {
> + dev_warn(port->dev, "Fatal error message\n");
> + xilinx_pcie_clear_err_interrupts(port);
> + }
> +
> + if (status & XILINX_PCIE_INTR_INTX) {
> + /* INTx interrupt received */
> + val = pcie_read(port, XILINX_PCIE_REG_RPIFR1);
> +
> + /* Check whether interrupt valid */
> + if (!(val & XILINX_PCIE_RPIFR1_INTR_VALID)) {
> + dev_warn(port->dev, "RP Intr FIFO1 read error\n");
> + return IRQ_HANDLED;
> + }
> +
> + /* Clear interrupt FIFO register 1 */
> + pcie_write(port, XILINX_PCIE_RPIFR1_ALL_MASK,
> + XILINX_PCIE_REG_RPIFR1);
> +
> + /* Handle INTx Interrupt */
> + val = ((val & XILINX_PCIE_RPIFR1_INTR_MASK) >>
> + XILINX_PCIE_RPIFR1_INTR_SHIFT) + 1;
> + generic_handle_irq(irq_find_mapping(port->irq_domain, val));
> + }
> +
> + if (status & XILINX_PCIE_INTR_MSI) {
> + /* MSI Interrupt */
> + val = pcie_read(port, XILINX_PCIE_REG_RPIFR1);
> +
> + if (!(val & XILINX_PCIE_RPIFR1_INTR_VALID)) {
> + dev_warn(port->dev, "RP Intr FIFO1 read error\n");
> + return IRQ_HANDLED;
> + }
> +
> + if (val & XILINX_PCIE_RPIFR1_MSI_INTR) {
> + msi_data = pcie_read(port, XILINX_PCIE_REG_RPIFR2) &
> + XILINX_PCIE_RPIFR2_MSG_DATA;
> +
> + /* Clear interrupt FIFO register 1 */
> + pcie_write(port, XILINX_PCIE_RPIFR1_ALL_MASK,
> + XILINX_PCIE_REG_RPIFR1);
> +
> + if (IS_ENABLED(CONFIG_PCI_MSI)) {
> + /* Handle MSI Interrupt */
> + generic_handle_irq(msi_data);
> + }
> + }
> + }
> +
> + if (status & XILINX_PCIE_INTR_SLV_UNSUPP)
> + dev_warn(port->dev, "Slave unsupported request\n");
> +
> + if (status & XILINX_PCIE_INTR_SLV_UNEXP)
> + dev_warn(port->dev, "Slave unexpected completion\n");
> +
> + if (status & XILINX_PCIE_INTR_SLV_COMPL)
> + dev_warn(port->dev, "Slave completion timeout\n");
> +
> + if (status & XILINX_PCIE_INTR_SLV_ERRP)
> + dev_warn(port->dev, "Slave Error Poison\n");
> +
> + if (status & XILINX_PCIE_INTR_SLV_CMPABT)
> + dev_warn(port->dev, "Slave Completer Abort\n");
> +
> + if (status & XILINX_PCIE_INTR_SLV_ILLBUR)
> + dev_warn(port->dev, "Slave Illegal Burst\n");
> +
> + if (status & XILINX_PCIE_INTR_MST_DECERR)
> + dev_warn(port->dev, "Master decode error\n");
> +
> + if (status & XILINX_PCIE_INTR_MST_SLVERR)
> + dev_warn(port->dev, "Master slave error\n");
> +
> + if (status & XILINX_PCIE_INTR_MST_ERRP)
> + dev_warn(port->dev, "Master error poison\n");
> +
> + /* Clear the Interrupt Decode register */
> + pcie_write(port, status, XILINX_PCIE_REG_IDR);
> +
> + return IRQ_HANDLED;
> +}
> +
> +/**
> + * xilinx_pcie_free_irq_domain - Free IRQ domain
> + * @port: PCIe port information
> + */
> +static void xilinx_pcie_free_irq_domain(struct xilinx_pcie_port *port)
> +{
> + int i;
> + u32 irq, num_irqs;
> +
> + /* Free IRQ Domain */
> + if (IS_ENABLED(CONFIG_PCI_MSI)) {
> +
> + free_pages(port->msi_pages, 0);
> +
> + num_irqs = XILINX_NUM_MSI_IRQS;
> + } else {
> + /* INTx */
> + num_irqs = 4;
> + }
> +
> + for (i = 0; i < num_irqs; i++) {
> + irq = irq_find_mapping(port->irq_domain, i);
> + if (irq > 0)
> + irq_dispose_mapping(irq);
> + }
> +
> + irq_domain_remove(port->irq_domain);
> +}
> +
> +/**
> + * xilinx_pcie_init_irq_domain - Initialize IRQ domain
> + * @port: PCIe port information
> + *
> + * Return: '0' on success and error value on failure
> + */
> +static int xilinx_pcie_init_irq_domain(struct xilinx_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 PTR_ERR(pcie_intc_node);
> + }
> +
> + port->irq_domain = irq_domain_add_linear(pcie_intc_node, 4,
> + &intx_domain_ops,
> + port);
> + if (!port->irq_domain) {
> + dev_err(dev, "Failed to get a INTx IRQ domain\n");
> + return PTR_ERR(port->irq_domain);
> + }
> +
> + /* Setup MSI */
> + if (IS_ENABLED(CONFIG_PCI_MSI)) {
> + port->irq_domain = irq_domain_add_linear(node,
> + XILINX_NUM_MSI_IRQS,
> + &msi_domain_ops,
> + &xilinx_pcie_msi_chip);
> + if (!port->irq_domain) {
> + dev_err(dev, "Failed to get a MSI IRQ domain\n");
> + return PTR_ERR(port->irq_domain);
> + }
> +
> + xilinx_pcie_enable_msi(port);
> + }
> +
> + return 0;
> +}
> +
> +/**
> + * xilinx_pcie_init_port - Initialize hardware
> + * @port: PCIe port information
> + */
> +static void xilinx_pcie_init_port(struct xilinx_pcie_port *port)
> +{
> + port->link_up = xilinx_pcie_is_link_up(port);
> + if (!port->link_up)
I'd use "if (port->link_up)" and reorder the dev_info() to avoid the
negation (trivial, I know, but why use the negative when the positive
works just as well?)
> + dev_info(port->dev, "PCIe Link is DOWN\n");
> + else
> + dev_info(port->dev, "PCIe Link is UP\n");
> +
> + /* Disable all interrupts*/
> + pcie_write(port, ~XILINX_PCIE_IDR_ALL_MASK,
> + XILINX_PCIE_REG_IMR);
> +
> + /* Clear pending interrupts */
> + pcie_write(port, pcie_read(port, XILINX_PCIE_REG_IDR) &
> + XILINX_PCIE_IMR_ALL_MASK,
> + XILINX_PCIE_REG_IDR);
> +
> + /* Enable all interrupts*/
Missing space before "*/" (also on "Disable all interrupts" comment).
> + pcie_write(port, XILINX_PCIE_IMR_ALL_MASK, XILINX_PCIE_REG_IMR);
> +
> + /* Enable the Bridge enable bit */
> + pcie_write(port, pcie_read(port, XILINX_PCIE_REG_RPSC) |
> + XILINX_PCIE_REG_RPSC_BEN,
> + XILINX_PCIE_REG_RPSC);
> +}
> +
> +/**
> + * xilinx_pcie_setup - Setup memory resources
> + * @nr: Bus number
> + * @sys: Per controller structure
> + *
> + * Return: '1' on success and error value on failure
Incorrect. No point in a comment that explains obvious code anyway.
But maybe DocBook requires it, and I guess it's OK then.
> + */
> +static int xilinx_pcie_setup(int nr, struct pci_sys_data *sys)
> +{
> + struct xilinx_pcie_port *port = sys_to_pcie(sys);
> +
> + list_splice_init(&port->resources, &sys->resources);
> +
> + return 1;
> +}
> +
> +/**
> + * xilinx_pcie_scan_bus - Scan PCIe bus for devices
> + * @nr: Bus number
> + * @sys: Per controller structure
> + *
> + * Return: Valid Bus pointer on success and NULL on failure
> + */
> +static struct pci_bus __init *xilinx_pcie_scan_bus(int nr,
> + struct pci_sys_data *sys)
> +{
> + struct xilinx_pcie_port *port = sys_to_pcie(sys);
> + struct pci_bus *bus;
> +
> + if (port) {
I think this test (and the BUG()) is superfluous. I don't think it's
possible to get here with sys->private_data == NULL. And if we do,
we'll take a null pointer fault and get a nice backtrace anyway.
> + port->root_busno = sys->busnr;
> + bus = pci_scan_root_bus(port->dev, sys->busnr, &xilinx_pcie_ops,
> + sys, &sys->resources);
> + } else {
> + bus = NULL;
> + BUG();
> + }
> +
> + return bus;
> +}
> +
> +
> +/**
> + * xilinx_pcie_parse_and_add_res - Add resources by parsing ranges
> + * @port: PCIe port information
> + *
> + * Return: '0' on success and error value on failure
> + */
> +static int xilinx_pcie_parse_and_add_res(struct xilinx_pcie_port *port)
> +{
> + struct device *dev = port->dev;
> + struct device_node *node = dev->of_node;
> + struct resource *mem;
> + resource_size_t offset;
> + struct of_pci_range_parser parser;
> + struct of_pci_range range;
> + struct pci_host_bridge_window *win;
> + int err = 0, mem_resno = 0;
> +
> + /* Get the ranges */
> + if (of_pci_range_parser_init(&parser, node)) {
> + dev_err(dev, "missing \"ranges\" property\n");
> + return -EINVAL;
> + }
> +
> + /* Parse the ranges and add the resources found to the list */
> + for_each_of_pci_range(&parser, &range) {
> +
> + if (mem_resno >= XILINX_MAX_NUM_RESOURCES) {
> + dev_err(dev, "Maximum memory resources exceeded\n");
> + return -EINVAL;
> + }
> +
> + mem = devm_kmalloc(dev, sizeof(*mem), GFP_KERNEL);
> + if (!mem) {
> + err = -ENOMEM;
> + goto free_resources;
> + }
> +
> + of_pci_range_to_resource(&range, node, mem);
> +
> + switch (mem->flags & IORESOURCE_TYPE_BITS) {
> + case IORESOURCE_MEM:
> + offset = range.cpu_addr - range.pci_addr;
> + mem_resno++;
> + break;
> + default:
> + err = -EINVAL;
> + break;
> + }
> +
> + if (err < 0) {
> + dev_warn(dev, "Invalid resource found %pR\n", mem);
> + continue;
> + }
> +
> + err = request_resource(&iomem_resource, mem);
> + if (err)
> + goto free_resources;
> +
> + pci_add_resource_offset(&port->resources, mem, offset);
> + }
> +
> + /* Get the bus range */
> + if (of_pci_parse_bus_range(node, &port->bus_range)) {
> + u32 val = pcie_read(port, XILINX_PCIE_REG_BIR);
> + u8 last;
> +
> + last = (val & XILINX_PCIE_BIR_ECAM_SZ_MASK) >>
> + XILINX_PCIE_BIR_ECAM_SZ_SHIFT;
> +
> + port->bus_range = (struct resource) {
> + .name = node->name,
> + .start = 0,
> + .end = last,
> + .flags = IORESOURCE_BUS,
> + };
> + }
> +
> + /* Register bus resource */
> + pci_add_resource(&port->resources, &port->bus_range);
> +
> + return 0;
> +
> +free_resources:
> + release_child_resources(&iomem_resource);
> + list_for_each_entry(win, &port->resources, list)
> + devm_kfree(dev, win->res);
> + pci_free_resource_list(&port->resources);
> +
> + return err;
> +}
> +
> +/**
> + * xilinx_pcie_parse_dt - Parse Device tree
> + * @port: PCIe port information
> + *
> + * Return: '0' on success and error value on failure
> + */
> +static int xilinx_pcie_parse_dt(struct xilinx_pcie_port *port)
> +{
> + struct device *dev = port->dev;
> + struct device_node *node = dev->of_node;
> + struct resource regs;
> + const char *type;
> + int err;
> +
> + type = of_get_property(node, "device_type", NULL);
> + if (!type || strcmp(type, "pci")) {
> + dev_err(dev, "invalid \"device_type\" %s\n", type);
> + return -EINVAL;
> + }
> +
> + err = of_address_to_resource(node, 0, ®s);
> + if (err) {
> + dev_err(dev, "missing \"reg\" property\n");
> + return err;
> + }
> +
> + port->reg_base = devm_ioremap_resource(dev, ®s);
> + if (IS_ERR(port->reg_base))
> + return PTR_ERR(port->reg_base);
> +
> + port->irq = irq_of_parse_and_map(node, 0);
> + err = devm_request_irq(dev, port->irq, xilinx_pcie_intr_handler,
> + IRQF_SHARED, "xilinx-pcie", port);
> + if (err) {
> + dev_err(dev, "unable to request irq %d\n", port->irq);
> + return err;
> + }
> +
> + return 0;
> +}
> +
> +/**
> + * xilinx_pcie_probe - Probe function
> + * @pdev: Platform device pointer
> + *
> + * Return: '0' on success and error value on failure
> + */
> +static int xilinx_pcie_probe(struct platform_device *pdev)
> +{
> + struct xilinx_pcie_port *port;
> + struct hw_pci hw;
> + struct device *dev = &pdev->dev;
> + int err;
> +
> + if (!dev->of_node)
> + return -ENODEV;
> +
> + port = devm_kzalloc(dev, sizeof(*port), GFP_KERNEL);
> + if (!port)
> + return -ENOMEM;
> +
> + port->dev = dev;
> +
> + err = xilinx_pcie_parse_dt(port);
> + if (err) {
> + dev_err(dev, "Parsing DT failed\n");
> + return err;
> + }
> +
> + xilinx_pcie_init_port(port);
> +
> + err = xilinx_pcie_init_irq_domain(port);
> + if (err) {
> + dev_err(dev, "Failed creating IRQ Domain\n");
> + return err;
> + }
> +
> + /*
> + * Parse PCI ranges, configuration bus range and
> + * request their resources
> + */
> + INIT_LIST_HEAD(&port->resources);
> + err = xilinx_pcie_parse_and_add_res(port);
> + if (err) {
> + dev_err(dev, "Failed adding resources\n");
> + return err;
> + }
> +
> + platform_set_drvdata(pdev, port);
> +
> + /* Register the device */
> + memset(&hw, 0, sizeof(hw));
> + hw = (struct hw_pci) {
> + .nr_controllers = 1,
> + .private_data = (void **)&port,
> + .setup = xilinx_pcie_setup,
> + .map_irq = of_irq_parse_and_map_pci,
> + .add_bus = xilinx_pcie_add_bus,
> + .scan = xilinx_pcie_scan_bus,
> + .ops = &xilinx_pcie_ops,
> + };
> + pci_common_init_dev(dev, &hw);
> +
> + return 0;
> +}
> +
> +/**
> + * xilinx_pcie_remove - Remove function
> + * @pdev: Platform device pointer
> + *
> + * Return: '0' always
> + */
> +static int xilinx_pcie_remove(struct platform_device *pdev)
> +{
> + struct xilinx_pcie_port *port = platform_get_drvdata(pdev);
> +
> + xilinx_pcie_free_irq_domain(port);
> +
> + return 0;
> +}
> +
> +static struct of_device_id xilinx_pcie_of_match[] = {
> + { .compatible = "xlnx,axi-pcie-host-1.00.a", },
> + {}
> +};
> +
> +static struct platform_driver xilinx_pcie_driver = {
> + .driver = {
> + .name = "xilinx-pcie",
> + .owner = THIS_MODULE,
> + .of_match_table = xilinx_pcie_of_match,
> + .suppress_bind_attrs = true,
> + },
> + .probe = xilinx_pcie_probe,
> + .remove = xilinx_pcie_remove,
> +};
> +module_platform_driver(xilinx_pcie_driver);
> +
> +MODULE_AUTHOR("Xilinx Inc");
> +MODULE_DESCRIPTION("Xilinx AXI PCIe driver");
> +MODULE_LICENSE("GPLv2");
I think you want "GPL v2" here (with the space; see
license_is_gpl_compatible()).
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