diff mbox

[v6,2/3] PCI: mobiveil: Add Mobiveil PCIe Host Bridge IP driver

Message ID 1519734024-32253-1-git-send-email-l.subrahmanya@mobiveil.co.in (mailing list archive)
State New, archived
Delegated to: Bjorn Helgaas
Headers show

Commit Message

Subrahmanya Lingappa Feb. 27, 2018, 12:20 p.m. UTC
Adds driver for Mobiveil AXI PCIe Host Bridge Soft IP -
GPEX 4.0, a PCIe gen4 IP. This IP has upto 8
outbound and inbound windows for the address translation.

Signed-off-by: Subrahmanya Lingappa <l.subrahmanya@mobiveil.co.in>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: linux-pci@vger.kernel.org
Cc: devicetree@vger.kernel.org
---
 drivers/pci/host/pcie-mobiveil.c | 692 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 692 insertions(+)
 create mode 100644 drivers/pci/host/pcie-mobiveil.c

Comments

Lorenzo Pieralisi March 9, 2018, 5:48 p.m. UTC | #1
On Tue, Feb 27, 2018 at 07:20:24AM -0500, Subrahmanya Lingappa wrote:
> Adds driver for Mobiveil AXI PCIe Host Bridge Soft IP -
> GPEX 4.0, a PCIe gen4 IP. This IP has upto 8
> outbound and inbound windows for the address translation.
> 
> Signed-off-by: Subrahmanya Lingappa <l.subrahmanya@mobiveil.co.in>
> Cc: Bjorn Helgaas <bhelgaas@google.com>
> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> Cc: Marc Zyngier <marc.zyngier@arm.com>
> Cc: linux-pci@vger.kernel.org
> Cc: devicetree@vger.kernel.org
> ---
>  drivers/pci/host/pcie-mobiveil.c | 692 +++++++++++++++++++++++++++++++++++++++
>  1 file changed, 692 insertions(+)
>  create mode 100644 drivers/pci/host/pcie-mobiveil.c
> 
> diff --git a/drivers/pci/host/pcie-mobiveil.c b/drivers/pci/host/pcie-mobiveil.c
> new file mode 100644
> index 0000000..4270387
> --- /dev/null
> +++ b/drivers/pci/host/pcie-mobiveil.c
> @@ -0,0 +1,692 @@
> +/*
> + * PCIe host controller driver for Mobiveil PCIe Host controller
> + *
> + * SPDX-License-Identifier: GPL-2.0
> + * Copyright (c) 2017 Mobiveil Inc.
> + * Author: Subrahmanya Lingappa <l.subrahmanya@mobiveil.co.in>
> + */
> +
> +#include <linux/delay.h>
> +#include <linux/interrupt.h>
> +#include <linux/init.h>

Nit: swap init.h and interrupt.h, alphabetical order.

[...]

> +/* supported number of interrupts */
> +#define PCI_NUM_INTX    4

It is already defined in PCI includes, remove it.

> +#define PAB_INTA_POS    5
                       ^^^^
This ought to be a tab.

> +/* outbound and inbound window definitions */
> +#define WIN_NUM_0		0
> +#define WIN_NUM_1		1
> +#define CFG_WINDOW_TYPE		0
> +#define IO_WINDOW_TYPE		1
> +#define MEM_WINDOW_TYPE		2
> +#define IB_WIN_SIZE		(256 * 1024 * 1024 * 1024)
> +#define MAX_PIO_WINDOWS		8
> +
> +/* Parameters for the waiting for link up routine */
> +#define LINK_WAIT_MAX_RETRIES	10
> +#define LINK_WAIT_MIN		90000
> +#define LINK_WAIT_MAX		100000
> +
> +struct mobiveil_pcie {
> +	struct platform_device *pdev;
> +	struct list_head resources;
> +	void __iomem *config_axi_slave_base;	/* endpoint config base */
> +	void __iomem *csr_axi_slave_base;   /* root port config base */
					^^^^

A tab please.

> +	void __iomem *pcie_reg_base;    /* Physical PCIe Controller Base */
Ditto.

> +	struct irq_domain *intx_domain;
> +	raw_spinlock_t intx_mask_lock;
> +	int irq;
> +	int apio_wins;
> +	int ppio_wins;
> +	int ob_wins_configured;	/*  configured outbound windows */
> +	int ib_wins_configured;	/*  configured inbound windows */
> +	struct resource *ob_io_res;
> +	char root_bus_nr;
> +};
> +
> +static inline void csr_writel(struct mobiveil_pcie *pcie, const u32 value,
> +		const u32 reg)
> +{
> +	writel_relaxed(value, pcie->csr_axi_slave_base + reg);
> +}
> +
> +static inline u32 csr_readl(struct mobiveil_pcie *pcie,	const u32 reg)
> +{
> +	return readl_relaxed(pcie->csr_axi_slave_base + reg);
> +}
> +
> +/*
> + * Routine to check the downstream link status, its recommended to
> + * check the link status before accessing downstream config resources.
> + */
> +static bool mobiveil_pcie_link_up(struct mobiveil_pcie *pcie)
> +{
> +	return (csr_readl(pcie, LTSSM_STATUS) &
> +		LTSSM_STATUS_L0_MASK) == LTSSM_STATUS_L0;
> +}
> +
> +static bool mobiveil_pcie_valid_device(struct pci_bus *bus, unsigned int devfn)
> +{
> +	struct mobiveil_pcie *pcie = bus->sysdata;
> +
> +	/* Check if link is up when trying to access downstream ports */
> +	if (bus->number != pcie->root_bus_nr)
> +		if (!mobiveil_pcie_link_up(pcie))

Do you really need this racy check ? Bjorn wants to remove it
from other drivers - what happens on surprise link loss on
your platform ?

> +			return false;
> +
> +	/* Only one device down on each root port */
> +	if ((bus->number == pcie->root_bus_nr) && (devfn > 0))
> +		return false;
> +
> +	/*
> +	 * Do not read more than one device on the bus directly
> +	 * attached to RC
> +	 */
> +	if ((bus->primary == pcie->root_bus_nr) && (devfn > 0))
> +		return false;
> +
> +	return true;
> +}
> +
> +/*
> + * mobiveil_pcie_map_bus - routine to get the configuration base of either
> + * root port or endpoint
> + */
> +static void __iomem *mobiveil_pcie_map_bus(struct pci_bus *bus,
> +					unsigned int devfn, int where)
> +{
> +	struct mobiveil_pcie *pcie = bus->sysdata;
> +
> +	if (!mobiveil_pcie_valid_device(bus, devfn))
> +		return NULL;
> +
> +	if (bus->number == pcie->root_bus_nr) {
> +		/* RC config access */
> +		return pcie->csr_axi_slave_base + where;
> +	} else {
> +		/*
> +		 * EP config access (in Config/APIO space)
> +		 * Program PEX Address base (31..16 bits) with appropriate value
> +		 * (BDF) in PAB_AXI_AMAP_PEX_WIN_L0 Register.
> +		 * Relies on pci_lock serialization
> +		 */
> +		csr_writel(pcie,
> +			bus->number << PAB_BUS_SHIFT |
> +			PCI_SLOT(devfn) << PAB_DEVICE_SHIFT |
> +			PCI_FUNC(devfn) << PAB_FUNCTION_SHIFT,
> +			PAB_AXI_AMAP_PEX_WIN_L(WIN_NUM_0));
> +		return pcie->config_axi_slave_base + where;
> +	}
> +}
> +
> +static struct pci_ops mobiveil_pcie_ops = {
> +	.map_bus = mobiveil_pcie_map_bus,
> +	.read = pci_generic_config_read,
> +	.write = pci_generic_config_write,
> +};
> +
> +static void mobiveil_pcie_isr(struct irq_desc *desc)
> +{
> +	struct irq_chip *chip = irq_desc_get_chip(desc);
> +	struct mobiveil_pcie *pcie = irq_desc_get_handler_data(desc);
> +	struct device *dev = &pcie->pdev->dev;
> +	unsigned long shifted_status;
> +	u32 bit, virq;
> +	u32 val, mask;

Nit: why two lines for same type.

> +	/*
> +	 * The core provides a single interrupt for both INTx/MSI messages.
> +	 * So we'll read both INTx and MSI status

Add a comment for INTX and update it in the next patch. This patch
only deals with INTX and the comment should reflect that.

> +	 */
> +
> +	chained_irq_enter(chip, desc);
> +
> +	/* read INTx status */
> +	val = csr_readl(pcie, PAB_INTP_AMBA_MISC_STAT);
> +	mask = csr_readl(pcie, PAB_INTP_AMBA_MISC_ENB);
> +	intr_status = val & mask;
> +
> +	/* Handle INTx */
> +	if (intr_status & PAB_INTP_INTX_MASK) {
> +		shifted_status = csr_readl(pcie, PAB_INTP_AMBA_MISC_STAT) >>
> +			PAB_INTA_POS;
> +		do {
> +			for_each_set_bit(bit, &shifted_status, PCI_NUM_INTX) {
> +				virq = irq_find_mapping(pcie->intx_domain,
> +						bit + 1);

It must be bit, not bit + 1. See DT bindings comment.

> +				if (virq)
> +					generic_handle_irq(virq);
> +				else
> +					dev_err_ratelimited(dev,
> +						"unexpected IRQ, INT%d\n", bit);
> +
> +				/* clear interrupt */
> +				csr_writel(pcie, shifted_status << PAB_INTA_POS,
> +						PAB_INTP_AMBA_MISC_STAT);
> +			}
> +		} while ((shifted_status >>  PAB_INTA_POS) != 0);
> +	}
> +
> +	/* Clear the interrupt status */
> +	csr_writel(pcie, intr_status, PAB_INTP_AMBA_MISC_STAT);
> +	chained_irq_exit(chip, desc);
> +}
> +
> +static int mobiveil_pcie_parse_dt(struct mobiveil_pcie *pcie)
> +{
> +	struct device *dev = &pcie->pdev->dev;
> +	struct platform_device *pdev = pcie->pdev;
> +	struct device_node *node = dev->of_node;
> +	struct resource *res;
> +	const char *type;
> +
> +	type = of_get_property(node, "device_type", NULL);
> +	if (!type || strcmp(type, "pci")) {
> +		dev_err(dev, "invalid \"device_type\" %s\n", type);
> +		return -EINVAL;
> +	}
> +
> +	/* map config resource */
> +	res = platform_get_resource_byname(pdev,
> +		IORESOURCE_MEM, "config_axi_slave");

What can fit in a line should stay in a line, so update this wrapping.

	res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
					   "config_axi_slave");

> +	pcie->config_axi_slave_base = devm_pci_remap_cfg_resource(dev, res);
> +	if (IS_ERR(pcie->config_axi_slave_base))
> +		return PTR_ERR(pcie->config_axi_slave_base);
> +	pcie->ob_io_res = res;
> +
> +	/* map csr resource */
> +	res = platform_get_resource_byname(pdev,
> +		IORESOURCE_MEM, "csr_axi_slave");

	res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
					   "csr_axi_slave");

> +	pcie->csr_axi_slave_base = devm_pci_remap_cfg_resource(dev, res);
> +	if (IS_ERR(pcie->csr_axi_slave_base))
> +		return PTR_ERR(pcie->csr_axi_slave_base);
> +	pcie->pcie_reg_base = res->start;
> +
> +	/* read the number of windows requested */
> +	if (of_property_read_u32(node, "apio-wins", &pcie->apio_wins))
> +		pcie->apio_wins = MAX_PIO_WINDOWS;
> +
> +	if (of_property_read_u32(node, "ppio-wins", &pcie->ppio_wins))
> +		pcie->ppio_wins = MAX_PIO_WINDOWS;
> +
> +	pcie->irq = platform_get_irq(pdev, 0);
> +	if (pcie->irq <= 0) {
> +		dev_err(dev, "failed to map IRQ: %d\n", pcie->irq);
> +		return -ENODEV;
> +	}
> +
> +	irq_set_chained_handler_and_data(pcie->irq, mobiveil_pcie_isr, pcie);
> +
> +	return 0;
> +}
> +
> +/*
> + * select_paged_register - routine to access paged register of root complex
> + *
> + * registers of RC are paged, for this scheme to work
> + * extracted higher 6 bits of the offset will be written to pg_sel
> + * field of PAB_CTRL register and rest of the lower 10 bits enabled with
> + * PAGE_SEL_EN are used as offset of the register.
> + *
> + */
> +static void select_paged_register(struct mobiveil_pcie *pcie, u32 offset)
> +{
> +	int pab_ctrl_dw, pg_sel;
> +
> +	/* clear pg_sel field */
> +	pab_ctrl_dw = csr_readl(pcie, PAB_CTRL);
> +	pab_ctrl_dw = (pab_ctrl_dw & ~(PAGE_SEL_MASK << PAGE_SEL_SHIFT));
> +
> +	/* set pg_sel field */
> +	pg_sel = (offset >> PAGE_SEL_OFFSET_SHIFT) & PAGE_SEL_MASK;
> +	pab_ctrl_dw |= ((pg_sel << PAGE_SEL_SHIFT));
> +	csr_writel(pcie, pab_ctrl_dw, PAB_CTRL);
> +}
> +
> +static void write_paged_register(struct mobiveil_pcie *pcie,
> +		u32 val, u32 offset)
> +{
> +	u32 off = (offset & PAGE_LO_MASK) | PAGE_SEL_EN;
> +
> +	select_paged_register(pcie, offset);
> +	csr_writel(pcie, val, off);
> +}
> +
> +static u32 read_paged_register(struct mobiveil_pcie *pcie, u32 offset)
> +{
> +	u32 off = (offset & PAGE_LO_MASK) | PAGE_SEL_EN;
> +
> +	select_paged_register(pcie, offset);
> +	return csr_readl(pcie, off);
> +}
> +
> +static void program_ib_windows(struct mobiveil_pcie *pcie, int win_num,
> +		int pci_addr, u32 type,	int size)

size must certainly not be a signed int and must be u64, for this reason
current windows are truncated if I am not mistaken so this is a bug.

> +{
> +	int pio_ctrl_val;
> +	int amap_ctrl_dw;
> +	u64 size64 =  ~(size-1);

Nit: 1 space before ~ is enough and you should add on both sides of
the minus sign (-).

I think you should round it though.

u64 mask = (1ULL << fls(size - 1)) - 1;

(mask or whatever you may call it)

> +
> +	if ((pcie->ib_wins_configured + 1) > pcie->ppio_wins) {
> +		dev_err(&pcie->pdev->dev,
> +			"ERROR: max inbound windows reached !\n");
> +		return;
> +	}
> +
> +	pio_ctrl_val = csr_readl(pcie, PAB_PEX_PIO_CTRL);
> +	csr_writel(pcie,
> +		pio_ctrl_val | (1 << PIO_ENABLE_SHIFT), PAB_PEX_PIO_CTRL);
> +	amap_ctrl_dw =	read_paged_register(pcie, PAB_PEX_AMAP_CTRL(win_num));
> +	amap_ctrl_dw = (amap_ctrl_dw | (type << AMAP_CTRL_TYPE_SHIFT));
> +	amap_ctrl_dw = (amap_ctrl_dw | (1 << AMAP_CTRL_EN_SHIFT));
> +
> +	write_paged_register(pcie, amap_ctrl_dw | lower_32_bits(size64),
> +				PAB_PEX_AMAP_CTRL(win_num));
> +
> +	write_paged_register(pcie, upper_32_bits(size64),
> +				PAB_EXT_PEX_AMAP_SIZEN(win_num));
> +
> +	write_paged_register(pcie, pci_addr, PAB_PEX_AMAP_AXI_WIN(win_num));
> +	write_paged_register(pcie, pci_addr, PAB_PEX_AMAP_PEX_WIN_L(win_num));
> +	write_paged_register(pcie, 0, PAB_PEX_AMAP_PEX_WIN_H(win_num));
> +}
> +
> +/*
> + * routine to program the outbound windows
> + */
> +static void program_ob_windows(struct mobiveil_pcie *pcie, int win_num,
> +		u64 cpu_addr, u64 pci_addr, u32 config_io_bit,
> +		int size)

You have a funny way of wrapping lines, even when that's not needed,
as in the last line.

> +{
> +
> +	u32 value, type;
> +	u64 size64 =  ~(size-1);

See above.

> +	if ((pcie->ob_wins_configured + 1) > pcie->apio_wins) {
> +		dev_err(&pcie->pdev->dev,
> +			"ERROR: max outbound windows reached !\n");
> +		return;
> +	}
> +
> +	/*
> +	 * program Enable Bit to 1, Type Bit to (00) base 2, AXI Window Size Bit
> +	 * to 4 KB in PAB_AXI_AMAP_CTRL register
> +	 */
> +	type = config_io_bit;
> +	value = csr_readl(pcie, PAB_AXI_AMAP_CTRL(win_num));
> +	csr_writel(pcie,
> +			1 << WIN_ENABLE_SHIFT |

What fits in a line should stay in a line.

> +			type << WIN_TYPE_SHIFT |
> +			lower_32_bits(size64),
> +			PAB_AXI_AMAP_CTRL(win_num));

Here:
	csr_writel(pcie, 1 << WIN_ENABLE_SHIFT |
			type << WIN_TYPE_SHIFT |
			lower_32_bits(size64), PAB_AXI_AMAP_CTRL(win_num));
> +	write_paged_register(pcie, upper_32_bits(size64),
> +				PAB_EXT_AXI_AMAP_SIZE(win_num));
> +
> +	/*
> +	 * program AXI window base with appropriate value in
> +	 * PAB_AXI_AMAP_AXI_WIN0 register
> +	 */
> +	value = csr_readl(pcie, PAB_AXI_AMAP_AXI_WIN(win_num));
> +	csr_writel(pcie,
> +			cpu_addr >> AXI_WINDOW_BASE_SHIFT <<
> +			AXI_WINDOW_BASE_SHIFT, PAB_AXI_AMAP_AXI_WIN(win_num));

Can you explain to me what this >> << is there for ?

> +	value = csr_readl(pcie, PAB_AXI_AMAP_PEX_WIN_H(win_num));
> +
> +	csr_writel(pcie, lower_32_bits(pci_addr),
> +			PAB_AXI_AMAP_PEX_WIN_L(win_num));
> +	csr_writel(pcie, upper_32_bits(pci_addr),
> +			PAB_AXI_AMAP_PEX_WIN_H(win_num));
> +
> +	pcie->ob_wins_configured++;
> +}
> +
> +static int mobiveil_bringup_link(struct mobiveil_pcie *pcie)
> +{
> +	int retries;
> +
> +	/* check if the link is up or not */
> +	for (retries = 0; retries < LINK_WAIT_MAX_RETRIES; retries++) {
> +		if (mobiveil_pcie_link_up(pcie))
> +			return 0;
> +
> +		usleep_range(LINK_WAIT_MIN, LINK_WAIT_MAX);
> +	}
> +	dev_err(&pcie->pdev->dev, "link never came up\n");
> +	return -ETIMEDOUT;
> +}
> +
> +static int mobiveil_host_init(struct mobiveil_pcie *pcie)
> +{
> +	u32 value;
> +	u32 type = 0;
> +	u32 pab_ctrl;

Why do you need three lines for the same type ?

> +	int err;
> +	struct resource_entry *win, *tmp;
> +
> +	err = mobiveil_bringup_link(pcie);
> +	if (err) {
> +		dev_info(&pcie->pdev->dev, "link bring-up failed\n");
> +		return err;
> +	}
> +
> +	/*
> +	 * program Bus Master Enable Bit in Command Register in PAB Config
> +	 * Space
> +	 */
> +	value = csr_readl(pcie, PCI_COMMAND);
> +	csr_writel(pcie, value | PCI_COMMAND_IO | PCI_COMMAND_MEMORY |
> +		PCI_COMMAND_MASTER,	PCI_COMMAND);
				   ^

Tab not needed, just a space.

> +	/*
> +	 * program PIO Enable Bit to 1 (and PEX PIO Enable to 1) in PAB_CTRL
> +	 * register
> +	 */
> +	pab_ctrl = csr_readl(pcie, PAB_CTRL);
> +	csr_writel(pcie, pab_ctrl | (1 << AMBA_PIO_ENABLE_SHIFT) |
> +		(1 << PEX_PIO_ENABLE_SHIFT),
> +		PAB_CTRL);
> +
> +	csr_writel(pcie, (PAB_INTP_INTX_MASK | PAB_INTP_MSI_MASK),
> +		PAB_INTP_AMBA_MISC_ENB);
> +
> +	/* program PIO Enable Bit to 1 and Config Window Enable Bit to 1 in
> +	 * PAB_AXI_PIO_CTRL Register
> +	 */
> +	value = csr_readl(pcie, PAB_AXI_PIO_CTRL);
> +	csr_writel(pcie, value | APIO_EN_MASK, PAB_AXI_PIO_CTRL);
> +
> +	/*
> +	 * we'll program one outbound window for config reads and
> +	 * another default inbound window for all the upstream traffic
> +	 * rest of the outbound windows will be configured according to
> +	 * the "ranges" field defined in device tree
> +	 */
> +
> +	/* config outbound translation window */
> +	program_ob_windows(pcie, pcie->ob_wins_configured,
> +			pcie->ob_io_res->start,	0, CFG_WINDOW_TYPE,
> +			resource_size(pcie->ob_io_res));
> +
> +	/* memory inbound  translation window */
> +	program_ib_windows(pcie, WIN_NUM_1, 0, MEM_WINDOW_TYPE, IB_WIN_SIZE);
> +
> +	/* Get the I/O and memory ranges from DT */
> +	resource_list_for_each_entry_safe(win, tmp, &pcie->resources) {
> +		type = 0;
> +		if (resource_type(win->res) == IORESOURCE_MEM)
> +			type = MEM_WINDOW_TYPE;
> +		if (resource_type(win->res) == IORESOURCE_IO)
> +			type = IO_WINDOW_TYPE;
> +		if (type) {
> +			/* configure outbound translation window */
> +			program_ob_windows(pcie, pcie->ob_wins_configured,
> +				win->res->start, 0, type,
> +				resource_size(win->res));
> +		}
> +	}
> +
> +	return err;
> +}
> +
> +static void mobiveil_mask_intx_irq(struct irq_data *data)
> +{
> +	struct irq_desc *desc = irq_to_desc(data->irq);
> +	struct mobiveil_pcie *pcie;
> +	unsigned long flags;
> +	u32 mask;
> +	u32 shifted_val;

All u32 variables in one line please.

> +	pcie = irq_desc_get_chip_data(desc);
> +	mask = 1 << ((data->hwirq + PAB_INTA_POS) - 1);
> +	raw_spin_lock_irqsave(&pcie->intx_mask_lock, flags);
> +	shifted_val = csr_readl(pcie, PAB_INTP_AMBA_MISC_ENB);
> +	csr_writel(pcie, (shifted_val & (~mask)), PAB_INTP_AMBA_MISC_ENB);
> +	raw_spin_unlock_irqrestore(&pcie->intx_mask_lock, flags);
> +}
> +
> +static void mobiveil_unmask_intx_irq(struct irq_data *data)
> +{
> +	struct irq_desc *desc = irq_to_desc(data->irq);
> +	struct mobiveil_pcie *pcie;
> +	unsigned long flags;
> +	u32 shifted_val;
> +	u32 mask;

All u32 in one line.

> +
> +	pcie = irq_desc_get_chip_data(desc);
> +	mask = 1 << ((data->hwirq + PAB_INTA_POS) - 1);
> +	raw_spin_lock_irqsave(&pcie->intx_mask_lock, flags);
> +	shifted_val = csr_readl(pcie, PAB_INTP_AMBA_MISC_ENB);
> +	csr_writel(pcie, (shifted_val | mask), PAB_INTP_AMBA_MISC_ENB);
> +	raw_spin_unlock_irqrestore(&pcie->intx_mask_lock, flags);
> +}
> +
> +static struct irq_chip intx_irq_chip = {
> +	.name = "mobiveil_pcie:intx",
> +	.irq_enable = mobiveil_unmask_intx_irq,
> +	.irq_disable = mobiveil_mask_intx_irq,
> +	.irq_mask = mobiveil_mask_intx_irq,
> +	.irq_unmask = mobiveil_unmask_intx_irq,
> +};
> +
> +/* routine to setup the INTx related data */
> +static int mobiveil_pcie_intx_map(struct irq_domain *domain, unsigned int irq,
> +		irq_hw_number_t hwirq)
> +{
> +	irq_set_chip_and_handler(irq, &intx_irq_chip, handle_simple_irq);
> +	irq_set_chip_data(irq, domain->host_data);
> +	return 0;
> +}
> +
> +/* INTx domain operations structure */
> +static const struct irq_domain_ops intx_domain_ops = {
> +	.map = mobiveil_pcie_intx_map,
> +	.xlate = pci_irqd_intx_xlate,

I do not think you need this xlate if you follow what's discussed in DT
bindings.

> +};
> +
> +static int mobiveil_pcie_init_irq_domain(struct mobiveil_pcie *pcie)
> +{
> +	struct device *dev = &pcie->pdev->dev;
> +	struct device_node *node = dev->of_node;
> +	int ret;
> +
> +	/* setup INTx */
> +	pcie->intx_domain = irq_domain_add_linear(node,
> +				PCI_NUM_INTX + 1, &intx_domain_ops, pcie);

Remove (+1).

> +	if (!pcie->intx_domain) {
> +		dev_err(dev, "Failed to get a INTx IRQ domain\n");
> +		return -ENODEV;
> +	}
> +
> +	raw_spin_lock_init(&pcie->intx_mask_lock);
> +
> +	return 0;
> +}
> +
> +static int mobiveil_pcie_probe(struct platform_device *pdev)
> +{
> +	struct mobiveil_pcie *pcie;
> +	struct pci_bus *bus;
> +	struct pci_bus *child;
> +	struct pci_host_bridge *bridge;
> +	struct device *dev = &pdev->dev;
> +	struct device_node *node = dev->of_node;
> +	resource_size_t iobase;
> +	int ret;
> +
> +	/* allocate the PCIe port */
> +	bridge = devm_pci_alloc_host_bridge(dev, sizeof(*pcie));
> +	if (!bridge)
> +		return -ENODEV;
> +
> +	pcie = pci_host_bridge_priv(bridge);
> +	if (!pcie)
> +		return -ENOMEM;
> +
> +	pcie->pdev = pdev;
> +
> +	ret = mobiveil_pcie_parse_dt(pcie);
> +	if (ret) {
> +		dev_err(dev, "Parsing DT failed, ret: %x\n", ret);
> +		return ret;
> +	}
> +
> +	INIT_LIST_HEAD(&pcie->resources);
> +
> +	/* parse the host bridge base addresses from the device tree file */
> +	ret = of_pci_get_host_bridge_resources(node,
> +			0, 0xff, &pcie->resources, &iobase);
> +	if (ret) {
> +		dev_err(dev, "Getting bridge resources failed\n");
> +		return -ENOMEM;
> +	}
> +
> +	/*
> +	 * configure all inbound and outbound windows and prepare the RC for
> +	 * config access
> +	 */
> +	ret = mobiveil_host_init(pcie);
> +	if (ret) {
> +		dev_err(dev, "Failed to initialize host\n");
> +		goto error;
> +	}
> +
> +	/* fixup for PCIe class register */
> +	csr_writel(pcie, 0x060402ab, PAB_INTP_AXI_PIO_CLASS);
> +
> +	/* initialize the IRQ domains */
> +	ret = mobiveil_pcie_init_irq_domain(pcie);
> +	if (ret) {
> +		dev_err(dev, "Failed creating IRQ Domain\n");
> +		goto error;
> +	}
> +
> +	ret = devm_request_pci_bus_resources(dev, &pcie->resources);
> +	if (ret)
> +		goto error;
> +
> +	/* Initialize bridge */
> +	list_splice_init(&pcie->resources, &bridge->windows);
> +	bridge->dev.parent = dev;
> +	bridge->sysdata = pcie;
> +	bridge->busnr = pcie->root_bus_nr;
> +	bridge->ops = &mobiveil_pcie_ops;
> +	bridge->map_irq = of_irq_parse_and_map_pci;
> +	bridge->swizzle_irq = pci_common_swizzle;
> +
> +	/* setup the kernel resources for the newly added PCIe root bus */
> +	ret = pci_scan_root_bus_bridge(bridge);
> +	if (ret)
> +		goto error;
> +
> +	bus = bridge->bus;
> +
> +	pci_assign_unassigned_bus_resources(bus);
> +	list_for_each_entry(child, &bus->children, node)
> +		pcie_bus_configure_settings(child);
> +	pci_bus_add_devices(bus);
> +
> +	platform_set_drvdata(pdev, pcie);

What's this needed for ?

> +	return 0;
> +error:
> +	pci_free_resource_list(&pcie->resources);
> +	return ret;
> +}
> +
> +static const struct of_device_id mobiveil_pcie_of_match[] = {
> +	{.compatible = "mbvl,gpex40-pcie",},
> +};
> +
> +MODULE_DEVICE_TABLE(of, mobiveil_pcie_of_match);
> +
> +static struct platform_driver mobiveil_pcie_driver = {
> +	.probe = mobiveil_pcie_probe,
> +	.driver = {
> +			.name = "mobiveil-pcie",
> +			.of_match_table = mobiveil_pcie_of_match,
> +			.suppress_bind_attrs = true,
> +		},
> +};
> +
> +builtin_platform_driver(mobiveil_pcie_driver);
> +
> +MODULE_LICENSE("GPL v2");
> +MODULE_DESCRIPTION("Mobiveil PCIe host controller driver");
> +MODULE_AUTHOR("Subrahmanya Lingappa <l.subrahmanya@mobiveil.co.in>");

Thanks,
Lorenzo
Lorenzo Pieralisi March 14, 2018, 6:04 p.m. UTC | #2
On Tue, Feb 27, 2018 at 07:20:24AM -0500, Subrahmanya Lingappa wrote:

[...]

> +static void mobiveil_mask_intx_irq(struct irq_data *data)
> +{
> +	struct irq_desc *desc = irq_to_desc(data->irq);
> +	struct mobiveil_pcie *pcie;
> +	unsigned long flags;
> +	u32 mask;
> +	u32 shifted_val;
> +
> +	pcie = irq_desc_get_chip_data(desc);
> +	mask = 1 << ((data->hwirq + PAB_INTA_POS) - 1);
> +	raw_spin_lock_irqsave(&pcie->intx_mask_lock, flags);
> +	shifted_val = csr_readl(pcie, PAB_INTP_AMBA_MISC_ENB);
> +	csr_writel(pcie, (shifted_val & (~mask)), PAB_INTP_AMBA_MISC_ENB);
> +	raw_spin_unlock_irqrestore(&pcie->intx_mask_lock, flags);
> +}
> +
> +static void mobiveil_unmask_intx_irq(struct irq_data *data)
> +{
> +	struct irq_desc *desc = irq_to_desc(data->irq);
> +	struct mobiveil_pcie *pcie;
> +	unsigned long flags;
> +	u32 shifted_val;
> +	u32 mask;
> +
> +	pcie = irq_desc_get_chip_data(desc);
> +	mask = 1 << ((data->hwirq + PAB_INTA_POS) - 1);
> +	raw_spin_lock_irqsave(&pcie->intx_mask_lock, flags);
> +	shifted_val = csr_readl(pcie, PAB_INTP_AMBA_MISC_ENB);
> +	csr_writel(pcie, (shifted_val | mask), PAB_INTP_AMBA_MISC_ENB);
> +	raw_spin_unlock_irqrestore(&pcie->intx_mask_lock, flags);
> +}
> +
> +static struct irq_chip intx_irq_chip = {
> +	.name = "mobiveil_pcie:intx",
> +	.irq_enable = mobiveil_unmask_intx_irq,
> +	.irq_disable = mobiveil_mask_intx_irq,
> +	.irq_mask = mobiveil_mask_intx_irq,
> +	.irq_unmask = mobiveil_unmask_intx_irq,
> +};
> +
> +/* routine to setup the INTx related data */
> +static int mobiveil_pcie_intx_map(struct irq_domain *domain, unsigned int irq,
> +		irq_hw_number_t hwirq)
> +{
> +	irq_set_chip_and_handler(irq, &intx_irq_chip, handle_simple_irq);

The flow handler must be handle_level_irq(); INTX are level IRQs, with
current code none of the above struct irq_chip methods would be called at
all, please read handle_simple_irq() comments and update (and test) the code
to handle_level_irq(). AFAICS the current driver does not handle IRQ
masking and acking at all (because handle_simple_irq() does not call the
relevant struct irq_chip methods).

Thank you,
Lorenzo

> +	irq_set_chip_data(irq, domain->host_data);
> +	return 0;
> +}
> +
> +/* INTx domain operations structure */
> +static const struct irq_domain_ops intx_domain_ops = {
> +	.map = mobiveil_pcie_intx_map,
> +	.xlate = pci_irqd_intx_xlate,
> +};
> +
> +static int mobiveil_pcie_init_irq_domain(struct mobiveil_pcie *pcie)
> +{
> +	struct device *dev = &pcie->pdev->dev;
> +	struct device_node *node = dev->of_node;
> +	int ret;
> +
> +	/* setup INTx */
> +	pcie->intx_domain = irq_domain_add_linear(node,
> +				PCI_NUM_INTX + 1, &intx_domain_ops, pcie);
> +
> +	if (!pcie->intx_domain) {
> +		dev_err(dev, "Failed to get a INTx IRQ domain\n");
> +		return -ENODEV;
> +	}
> +
> +	raw_spin_lock_init(&pcie->intx_mask_lock);
> +
> +	return 0;
> +}
> +
> +static int mobiveil_pcie_probe(struct platform_device *pdev)
> +{
> +	struct mobiveil_pcie *pcie;
> +	struct pci_bus *bus;
> +	struct pci_bus *child;
> +	struct pci_host_bridge *bridge;
> +	struct device *dev = &pdev->dev;
> +	struct device_node *node = dev->of_node;
> +	resource_size_t iobase;
> +	int ret;
> +
> +	/* allocate the PCIe port */
> +	bridge = devm_pci_alloc_host_bridge(dev, sizeof(*pcie));
> +	if (!bridge)
> +		return -ENODEV;
> +
> +	pcie = pci_host_bridge_priv(bridge);
> +	if (!pcie)
> +		return -ENOMEM;
> +
> +	pcie->pdev = pdev;
> +
> +	ret = mobiveil_pcie_parse_dt(pcie);
> +	if (ret) {
> +		dev_err(dev, "Parsing DT failed, ret: %x\n", ret);
> +		return ret;
> +	}
> +
> +	INIT_LIST_HEAD(&pcie->resources);
> +
> +	/* parse the host bridge base addresses from the device tree file */
> +	ret = of_pci_get_host_bridge_resources(node,
> +			0, 0xff, &pcie->resources, &iobase);
> +	if (ret) {
> +		dev_err(dev, "Getting bridge resources failed\n");
> +		return -ENOMEM;
> +	}
> +
> +	/*
> +	 * configure all inbound and outbound windows and prepare the RC for
> +	 * config access
> +	 */
> +	ret = mobiveil_host_init(pcie);
> +	if (ret) {
> +		dev_err(dev, "Failed to initialize host\n");
> +		goto error;
> +	}
> +
> +	/* fixup for PCIe class register */
> +	csr_writel(pcie, 0x060402ab, PAB_INTP_AXI_PIO_CLASS);
> +
> +	/* initialize the IRQ domains */
> +	ret = mobiveil_pcie_init_irq_domain(pcie);
> +	if (ret) {
> +		dev_err(dev, "Failed creating IRQ Domain\n");
> +		goto error;
> +	}
> +
> +	ret = devm_request_pci_bus_resources(dev, &pcie->resources);
> +	if (ret)
> +		goto error;
> +
> +	/* Initialize bridge */
> +	list_splice_init(&pcie->resources, &bridge->windows);
> +	bridge->dev.parent = dev;
> +	bridge->sysdata = pcie;
> +	bridge->busnr = pcie->root_bus_nr;
> +	bridge->ops = &mobiveil_pcie_ops;
> +	bridge->map_irq = of_irq_parse_and_map_pci;
> +	bridge->swizzle_irq = pci_common_swizzle;
> +
> +	/* setup the kernel resources for the newly added PCIe root bus */
> +	ret = pci_scan_root_bus_bridge(bridge);
> +	if (ret)
> +		goto error;
> +
> +	bus = bridge->bus;
> +
> +	pci_assign_unassigned_bus_resources(bus);
> +	list_for_each_entry(child, &bus->children, node)
> +		pcie_bus_configure_settings(child);
> +	pci_bus_add_devices(bus);
> +
> +	platform_set_drvdata(pdev, pcie);
> +
> +	return 0;
> +error:
> +	pci_free_resource_list(&pcie->resources);
> +	return ret;
> +}
> +
> +static const struct of_device_id mobiveil_pcie_of_match[] = {
> +	{.compatible = "mbvl,gpex40-pcie",},
> +};
> +
> +MODULE_DEVICE_TABLE(of, mobiveil_pcie_of_match);
> +
> +static struct platform_driver mobiveil_pcie_driver = {
> +	.probe = mobiveil_pcie_probe,
> +	.driver = {
> +			.name = "mobiveil-pcie",
> +			.of_match_table = mobiveil_pcie_of_match,
> +			.suppress_bind_attrs = true,
> +		},
> +};
> +
> +builtin_platform_driver(mobiveil_pcie_driver);
> +
> +MODULE_LICENSE("GPL v2");
> +MODULE_DESCRIPTION("Mobiveil PCIe host controller driver");
> +MODULE_AUTHOR("Subrahmanya Lingappa <l.subrahmanya@mobiveil.co.in>");
> -- 
> 1.8.3.1
>
Subrahmanya Lingappa March 27, 2018, 8:16 a.m. UTC | #3
Lorenzo,
changed this to use handle_level_irq() and tested successfully, will
add this to the next version of patch.

Thanks.

On Wed, Mar 14, 2018 at 11:34 PM, Lorenzo Pieralisi
<lorenzo.pieralisi@arm.com> wrote:
> On Tue, Feb 27, 2018 at 07:20:24AM -0500, Subrahmanya Lingappa wrote:
>
> [...]
>
>> +static void mobiveil_mask_intx_irq(struct irq_data *data)
>> +{
>> +     struct irq_desc *desc = irq_to_desc(data->irq);
>> +     struct mobiveil_pcie *pcie;
>> +     unsigned long flags;
>> +     u32 mask;
>> +     u32 shifted_val;
>> +
>> +     pcie = irq_desc_get_chip_data(desc);
>> +     mask = 1 << ((data->hwirq + PAB_INTA_POS) - 1);
>> +     raw_spin_lock_irqsave(&pcie->intx_mask_lock, flags);
>> +     shifted_val = csr_readl(pcie, PAB_INTP_AMBA_MISC_ENB);
>> +     csr_writel(pcie, (shifted_val & (~mask)), PAB_INTP_AMBA_MISC_ENB);
>> +     raw_spin_unlock_irqrestore(&pcie->intx_mask_lock, flags);
>> +}
>> +
>> +static void mobiveil_unmask_intx_irq(struct irq_data *data)
>> +{
>> +     struct irq_desc *desc = irq_to_desc(data->irq);
>> +     struct mobiveil_pcie *pcie;
>> +     unsigned long flags;
>> +     u32 shifted_val;
>> +     u32 mask;
>> +
>> +     pcie = irq_desc_get_chip_data(desc);
>> +     mask = 1 << ((data->hwirq + PAB_INTA_POS) - 1);
>> +     raw_spin_lock_irqsave(&pcie->intx_mask_lock, flags);
>> +     shifted_val = csr_readl(pcie, PAB_INTP_AMBA_MISC_ENB);
>> +     csr_writel(pcie, (shifted_val | mask), PAB_INTP_AMBA_MISC_ENB);
>> +     raw_spin_unlock_irqrestore(&pcie->intx_mask_lock, flags);
>> +}
>> +
>> +static struct irq_chip intx_irq_chip = {
>> +     .name = "mobiveil_pcie:intx",
>> +     .irq_enable = mobiveil_unmask_intx_irq,
>> +     .irq_disable = mobiveil_mask_intx_irq,
>> +     .irq_mask = mobiveil_mask_intx_irq,
>> +     .irq_unmask = mobiveil_unmask_intx_irq,
>> +};
>> +
>> +/* routine to setup the INTx related data */
>> +static int mobiveil_pcie_intx_map(struct irq_domain *domain, unsigned int irq,
>> +             irq_hw_number_t hwirq)
>> +{
>> +     irq_set_chip_and_handler(irq, &intx_irq_chip, handle_simple_irq);
>
> The flow handler must be handle_level_irq(); INTX are level IRQs, with
> current code none of the above struct irq_chip methods would be called at
> all, please read handle_simple_irq() comments and update (and test) the code
> to handle_level_irq(). AFAICS the current driver does not handle IRQ
> masking and acking at all (because handle_simple_irq() does not call the
> relevant struct irq_chip methods).
>
> Thank you,
> Lorenzo
>
>> +     irq_set_chip_data(irq, domain->host_data);
>> +     return 0;
>> +}
>> +
>> +/* INTx domain operations structure */
>> +static const struct irq_domain_ops intx_domain_ops = {
>> +     .map = mobiveil_pcie_intx_map,
>> +     .xlate = pci_irqd_intx_xlate,
>> +};
>> +
>> +static int mobiveil_pcie_init_irq_domain(struct mobiveil_pcie *pcie)
>> +{
>> +     struct device *dev = &pcie->pdev->dev;
>> +     struct device_node *node = dev->of_node;
>> +     int ret;
>> +
>> +     /* setup INTx */
>> +     pcie->intx_domain = irq_domain_add_linear(node,
>> +                             PCI_NUM_INTX + 1, &intx_domain_ops, pcie);
>> +
>> +     if (!pcie->intx_domain) {
>> +             dev_err(dev, "Failed to get a INTx IRQ domain\n");
>> +             return -ENODEV;
>> +     }
>> +
>> +     raw_spin_lock_init(&pcie->intx_mask_lock);
>> +
>> +     return 0;
>> +}
>> +
>> +static int mobiveil_pcie_probe(struct platform_device *pdev)
>> +{
>> +     struct mobiveil_pcie *pcie;
>> +     struct pci_bus *bus;
>> +     struct pci_bus *child;
>> +     struct pci_host_bridge *bridge;
>> +     struct device *dev = &pdev->dev;
>> +     struct device_node *node = dev->of_node;
>> +     resource_size_t iobase;
>> +     int ret;
>> +
>> +     /* allocate the PCIe port */
>> +     bridge = devm_pci_alloc_host_bridge(dev, sizeof(*pcie));
>> +     if (!bridge)
>> +             return -ENODEV;
>> +
>> +     pcie = pci_host_bridge_priv(bridge);
>> +     if (!pcie)
>> +             return -ENOMEM;
>> +
>> +     pcie->pdev = pdev;
>> +
>> +     ret = mobiveil_pcie_parse_dt(pcie);
>> +     if (ret) {
>> +             dev_err(dev, "Parsing DT failed, ret: %x\n", ret);
>> +             return ret;
>> +     }
>> +
>> +     INIT_LIST_HEAD(&pcie->resources);
>> +
>> +     /* parse the host bridge base addresses from the device tree file */
>> +     ret = of_pci_get_host_bridge_resources(node,
>> +                     0, 0xff, &pcie->resources, &iobase);
>> +     if (ret) {
>> +             dev_err(dev, "Getting bridge resources failed\n");
>> +             return -ENOMEM;
>> +     }
>> +
>> +     /*
>> +      * configure all inbound and outbound windows and prepare the RC for
>> +      * config access
>> +      */
>> +     ret = mobiveil_host_init(pcie);
>> +     if (ret) {
>> +             dev_err(dev, "Failed to initialize host\n");
>> +             goto error;
>> +     }
>> +
>> +     /* fixup for PCIe class register */
>> +     csr_writel(pcie, 0x060402ab, PAB_INTP_AXI_PIO_CLASS);
>> +
>> +     /* initialize the IRQ domains */
>> +     ret = mobiveil_pcie_init_irq_domain(pcie);
>> +     if (ret) {
>> +             dev_err(dev, "Failed creating IRQ Domain\n");
>> +             goto error;
>> +     }
>> +
>> +     ret = devm_request_pci_bus_resources(dev, &pcie->resources);
>> +     if (ret)
>> +             goto error;
>> +
>> +     /* Initialize bridge */
>> +     list_splice_init(&pcie->resources, &bridge->windows);
>> +     bridge->dev.parent = dev;
>> +     bridge->sysdata = pcie;
>> +     bridge->busnr = pcie->root_bus_nr;
>> +     bridge->ops = &mobiveil_pcie_ops;
>> +     bridge->map_irq = of_irq_parse_and_map_pci;
>> +     bridge->swizzle_irq = pci_common_swizzle;
>> +
>> +     /* setup the kernel resources for the newly added PCIe root bus */
>> +     ret = pci_scan_root_bus_bridge(bridge);
>> +     if (ret)
>> +             goto error;
>> +
>> +     bus = bridge->bus;
>> +
>> +     pci_assign_unassigned_bus_resources(bus);
>> +     list_for_each_entry(child, &bus->children, node)
>> +             pcie_bus_configure_settings(child);
>> +     pci_bus_add_devices(bus);
>> +
>> +     platform_set_drvdata(pdev, pcie);
>> +
>> +     return 0;
>> +error:
>> +     pci_free_resource_list(&pcie->resources);
>> +     return ret;
>> +}
>> +
>> +static const struct of_device_id mobiveil_pcie_of_match[] = {
>> +     {.compatible = "mbvl,gpex40-pcie",},
>> +};
>> +
>> +MODULE_DEVICE_TABLE(of, mobiveil_pcie_of_match);
>> +
>> +static struct platform_driver mobiveil_pcie_driver = {
>> +     .probe = mobiveil_pcie_probe,
>> +     .driver = {
>> +                     .name = "mobiveil-pcie",
>> +                     .of_match_table = mobiveil_pcie_of_match,
>> +                     .suppress_bind_attrs = true,
>> +             },
>> +};
>> +
>> +builtin_platform_driver(mobiveil_pcie_driver);
>> +
>> +MODULE_LICENSE("GPL v2");
>> +MODULE_DESCRIPTION("Mobiveil PCIe host controller driver");
>> +MODULE_AUTHOR("Subrahmanya Lingappa <l.subrahmanya@mobiveil.co.in>");
>> --
>> 1.8.3.1
>>
Subrahmanya Lingappa March 27, 2018, 11:53 a.m. UTC | #4
Lorenzo,

On Fri, Mar 9, 2018 at 11:18 PM, Lorenzo Pieralisi
<lorenzo.pieralisi@arm.com> wrote:
>
> On Tue, Feb 27, 2018 at 07:20:24AM -0500, Subrahmanya Lingappa wrote:
> > Adds driver for Mobiveil AXI PCIe Host Bridge Soft IP -
> > GPEX 4.0, a PCIe gen4 IP. This IP has upto 8
> > outbound and inbound windows for the address translation.
> >
> > Signed-off-by: Subrahmanya Lingappa <l.subrahmanya@mobiveil.co.in>
> > Cc: Bjorn Helgaas <bhelgaas@google.com>
> > Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> > Cc: Marc Zyngier <marc.zyngier@arm.com>
> > Cc: linux-pci@vger.kernel.org
> > Cc: devicetree@vger.kernel.org
> > ---
> >  drivers/pci/host/pcie-mobiveil.c | 692 +++++++++++++++++++++++++++++++++++++++
> >  1 file changed, 692 insertions(+)
> >  create mode 100644 drivers/pci/host/pcie-mobiveil.c
> >
> > diff --git a/drivers/pci/host/pcie-mobiveil.c b/drivers/pci/host/pcie-mobiveil.c
> > new file mode 100644
> > index 0000000..4270387
> > --- /dev/null
> > +++ b/drivers/pci/host/pcie-mobiveil.c
> > @@ -0,0 +1,692 @@
> > +/*
> > + * PCIe host controller driver for Mobiveil PCIe Host controller
> > + *
> > + * SPDX-License-Identifier: GPL-2.0
> > + * Copyright (c) 2017 Mobiveil Inc.
> > + * Author: Subrahmanya Lingappa <l.subrahmanya@mobiveil.co.in>
> > + */
> > +
> > +#include <linux/delay.h>
> > +#include <linux/interrupt.h>
> > +#include <linux/init.h>
>
> Nit: swap init.h and interrupt.h, alphabetical order.
>
> [...]
>
> > +/* supported number of interrupts */
> > +#define PCI_NUM_INTX    4
>
> It is already defined in PCI includes, remove it.
>
> > +#define PAB_INTA_POS    5
>                        ^^^^
> This ought to be a tab.
>
> > +/* outbound and inbound window definitions */
> > +#define WIN_NUM_0            0
> > +#define WIN_NUM_1            1
> > +#define CFG_WINDOW_TYPE              0
> > +#define IO_WINDOW_TYPE               1
> > +#define MEM_WINDOW_TYPE              2
> > +#define IB_WIN_SIZE          (256 * 1024 * 1024 * 1024)
> > +#define MAX_PIO_WINDOWS              8
> > +
> > +/* Parameters for the waiting for link up routine */
> > +#define LINK_WAIT_MAX_RETRIES        10
> > +#define LINK_WAIT_MIN                90000
> > +#define LINK_WAIT_MAX                100000
> > +
> > +struct mobiveil_pcie {
> > +     struct platform_device *pdev;
> > +     struct list_head resources;
> > +     void __iomem *config_axi_slave_base;    /* endpoint config base */
> > +     void __iomem *csr_axi_slave_base;   /* root port config base */
>                                         ^^^^
>
> A tab please.
>
> > +     void __iomem *pcie_reg_base;    /* Physical PCIe Controller Base */
> Ditto.
>
> > +     struct irq_domain *intx_domain;
> > +     raw_spinlock_t intx_mask_lock;
> > +     int irq;
> > +     int apio_wins;
> > +     int ppio_wins;
> > +     int ob_wins_configured; /*  configured outbound windows */
> > +     int ib_wins_configured; /*  configured inbound windows */
> > +     struct resource *ob_io_res;
> > +     char root_bus_nr;
> > +};
> > +
> > +static inline void csr_writel(struct mobiveil_pcie *pcie, const u32 value,
> > +             const u32 reg)
> > +{
> > +     writel_relaxed(value, pcie->csr_axi_slave_base + reg);
> > +}
> > +
> > +static inline u32 csr_readl(struct mobiveil_pcie *pcie,      const u32 reg)
> > +{
> > +     return readl_relaxed(pcie->csr_axi_slave_base + reg);
> > +}
> > +
> > +/*
> > + * Routine to check the downstream link status, its recommended to
> > + * check the link status before accessing downstream config resources.
> > + */
> > +static bool mobiveil_pcie_link_up(struct mobiveil_pcie *pcie)
> > +{
> > +     return (csr_readl(pcie, LTSSM_STATUS) &
> > +             LTSSM_STATUS_L0_MASK) == LTSSM_STATUS_L0;
> > +}
> > +
> > +static bool mobiveil_pcie_valid_device(struct pci_bus *bus, unsigned int devfn)
> > +{
> > +     struct mobiveil_pcie *pcie = bus->sysdata;
> > +
> > +     /* Check if link is up when trying to access downstream ports */
> > +     if (bus->number != pcie->root_bus_nr)
> > +             if (!mobiveil_pcie_link_up(pcie))
>
> Do you really need this racy check ? Bjorn wants to remove it
> from other drivers - what happens on surprise link loss on
> your platform ?
>
> > +                     return false;
> > +
> > +     /* Only one device down on each root port */
> > +     if ((bus->number == pcie->root_bus_nr) && (devfn > 0))
> > +             return false;
> > +
> > +     /*
> > +      * Do not read more than one device on the bus directly
> > +      * attached to RC
> > +      */
> > +     if ((bus->primary == pcie->root_bus_nr) && (devfn > 0))
> > +             return false;
> > +
> > +     return true;
> > +}
> > +
> > +/*
> > + * mobiveil_pcie_map_bus - routine to get the configuration base of either
> > + * root port or endpoint
> > + */
> > +static void __iomem *mobiveil_pcie_map_bus(struct pci_bus *bus,
> > +                                     unsigned int devfn, int where)
> > +{
> > +     struct mobiveil_pcie *pcie = bus->sysdata;
> > +
> > +     if (!mobiveil_pcie_valid_device(bus, devfn))
> > +             return NULL;
> > +
> > +     if (bus->number == pcie->root_bus_nr) {
> > +             /* RC config access */
> > +             return pcie->csr_axi_slave_base + where;
> > +     } else {
> > +             /*
> > +              * EP config access (in Config/APIO space)
> > +              * Program PEX Address base (31..16 bits) with appropriate value
> > +              * (BDF) in PAB_AXI_AMAP_PEX_WIN_L0 Register.
> > +              * Relies on pci_lock serialization
> > +              */
> > +             csr_writel(pcie,
> > +                     bus->number << PAB_BUS_SHIFT |
> > +                     PCI_SLOT(devfn) << PAB_DEVICE_SHIFT |
> > +                     PCI_FUNC(devfn) << PAB_FUNCTION_SHIFT,
> > +                     PAB_AXI_AMAP_PEX_WIN_L(WIN_NUM_0));
> > +             return pcie->config_axi_slave_base + where;
> > +     }
> > +}
> > +
> > +static struct pci_ops mobiveil_pcie_ops = {
> > +     .map_bus = mobiveil_pcie_map_bus,
> > +     .read = pci_generic_config_read,
> > +     .write = pci_generic_config_write,
> > +};
> > +
> > +static void mobiveil_pcie_isr(struct irq_desc *desc)
> > +{
> > +     struct irq_chip *chip = irq_desc_get_chip(desc);
> > +     struct mobiveil_pcie *pcie = irq_desc_get_handler_data(desc);
> > +     struct device *dev = &pcie->pdev->dev;
> > +     unsigned long shifted_status;
> > +     u32 bit, virq;
> > +     u32 val, mask;
>
> Nit: why two lines for same type.
>
> > +     /*
> > +      * The core provides a single interrupt for both INTx/MSI messages.
> > +      * So we'll read both INTx and MSI status
>
> Add a comment for INTX and update it in the next patch. This patch
> only deals with INTX and the comment should reflect that.
>
> > +      */
> > +
> > +     chained_irq_enter(chip, desc);
> > +
> > +     /* read INTx status */
> > +     val = csr_readl(pcie, PAB_INTP_AMBA_MISC_STAT);
> > +     mask = csr_readl(pcie, PAB_INTP_AMBA_MISC_ENB);
> > +     intr_status = val & mask;
> > +
> > +     /* Handle INTx */
> > +     if (intr_status & PAB_INTP_INTX_MASK) {
> > +             shifted_status = csr_readl(pcie, PAB_INTP_AMBA_MISC_STAT) >>
> > +                     PAB_INTA_POS;
> > +             do {
> > +                     for_each_set_bit(bit, &shifted_status,
> PCI_NUM_INTX) {
> > +                             virq = irq_find_mapping(pcie->intx_domain,
> > +                                             bit + 1);
>
> It must be bit, not bit + 1. See DT bindings comment.
>

hwirq for legacy domain is being assigned by kernel PCIe subsystem
based on PCI_INTERRUPT_PIN, which as per
protocol starts from 1 and not zero, due to this 1 is being added.
Please correct me if wrong, even after fixing the DT binding we need
this change, DT binding fix can take care of removing (PCI_NUM_INTX +
1) at domain initialization time only I suppose ?

>
> > +                             if (virq)
> > +                                     generic_handle_irq(virq);
> > +                             else
> > +                                     dev_err_ratelimited(dev,
> > +                                             "unexpected IRQ, INT%d\n", bit);
> > +
> > +                             /* clear interrupt */
> > +                             csr_writel(pcie, shifted_status << PAB_INTA_POS,
> > +                                             PAB_INTP_AMBA_MISC_STAT);
> > +                     }
> > +             } while ((shifted_status >>  PAB_INTA_POS) != 0);
> > +     }
> > +
> > +     /* Clear the interrupt status */
> > +     csr_writel(pcie, intr_status, PAB_INTP_AMBA_MISC_STAT);
> > +     chained_irq_exit(chip, desc);
> > +}
> > +
> > +static int mobiveil_pcie_parse_dt(struct mobiveil_pcie *pcie)
> > +{
> > +     struct device *dev = &pcie->pdev->dev;
> > +     struct platform_device *pdev = pcie->pdev;
> > +     struct device_node *node = dev->of_node;
> > +     struct resource *res;
> > +     const char *type;
> > +
> > +     type = of_get_property(node, "device_type", NULL);
> > +     if (!type || strcmp(type, "pci")) {
> > +             dev_err(dev, "invalid \"device_type\" %s\n", type);
> > +             return -EINVAL;
> > +     }
> > +
> > +     /* map config resource */
> > +     res = platform_get_resource_byname(pdev,
> > +             IORESOURCE_MEM, "config_axi_slave");
>
> What can fit in a line should stay in a line, so update this wrapping.
>
>         res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
>                                            "config_axi_slave");
>
> > +     pcie->config_axi_slave_base = devm_pci_remap_cfg_resource(dev, res);
> > +     if (IS_ERR(pcie->config_axi_slave_base))
> > +             return PTR_ERR(pcie->config_axi_slave_base);
> > +     pcie->ob_io_res = res;
> > +
> > +     /* map csr resource */
> > +     res = platform_get_resource_byname(pdev,
> > +             IORESOURCE_MEM, "csr_axi_slave");
>
>         res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
>                                            "csr_axi_slave");
>
> > +     pcie->csr_axi_slave_base = devm_pci_remap_cfg_resource(dev, res);
> > +     if (IS_ERR(pcie->csr_axi_slave_base))
> > +             return PTR_ERR(pcie->csr_axi_slave_base);
> > +     pcie->pcie_reg_base = res->start;
> > +
> > +     /* read the number of windows requested */
> > +     if (of_property_read_u32(node, "apio-wins", &pcie->apio_wins))
> > +             pcie->apio_wins = MAX_PIO_WINDOWS;
> > +
> > +     if (of_property_read_u32(node, "ppio-wins", &pcie->ppio_wins))
> > +             pcie->ppio_wins = MAX_PIO_WINDOWS;
> > +
> > +     pcie->irq = platform_get_irq(pdev, 0);
> > +     if (pcie->irq <= 0) {
> > +             dev_err(dev, "failed to map IRQ: %d\n", pcie->irq);
> > +             return -ENODEV;
> > +     }
> > +
> > +     irq_set_chained_handler_and_data(pcie->irq, mobiveil_pcie_isr, pcie);
> > +
> > +     return 0;
> > +}
> > +
> > +/*
> > + * select_paged_register - routine to access paged register of root complex
> > + *
> > + * registers of RC are paged, for this scheme to work
> > + * extracted higher 6 bits of the offset will be written to pg_sel
> > + * field of PAB_CTRL register and rest of the lower 10 bits enabled with
> > + * PAGE_SEL_EN are used as offset of the register.
> > + *
> > + */
> > +static void select_paged_register(struct mobiveil_pcie *pcie, u32 offset)
> > +{
> > +     int pab_ctrl_dw, pg_sel;
> > +
> > +     /* clear pg_sel field */
> > +     pab_ctrl_dw = csr_readl(pcie, PAB_CTRL);
> > +     pab_ctrl_dw = (pab_ctrl_dw & ~(PAGE_SEL_MASK << PAGE_SEL_SHIFT));
> > +
> > +     /* set pg_sel field */
> > +     pg_sel = (offset >> PAGE_SEL_OFFSET_SHIFT) & PAGE_SEL_MASK;
> > +     pab_ctrl_dw |= ((pg_sel << PAGE_SEL_SHIFT));
> > +     csr_writel(pcie, pab_ctrl_dw, PAB_CTRL);
> > +}
> > +
> > +static void write_paged_register(struct mobiveil_pcie *pcie,
> > +             u32 val, u32 offset)
> > +{
> > +     u32 off = (offset & PAGE_LO_MASK) | PAGE_SEL_EN;
> > +
> > +     select_paged_register(pcie, offset);
> > +     csr_writel(pcie, val, off);
> > +}
> > +
> > +static u32 read_paged_register(struct mobiveil_pcie *pcie, u32 offset)
> > +{
> > +     u32 off = (offset & PAGE_LO_MASK) | PAGE_SEL_EN;
> > +
> > +     select_paged_register(pcie, offset);
> > +     return csr_readl(pcie, off);
> > +}
> > +
> > +static void program_ib_windows(struct mobiveil_pcie *pcie, int win_num,
> > +             int pci_addr, u32 type, int size)
>
> size must certainly not be a signed int and must be u64, for this reason
> current windows are truncated if I am not mistaken so this is a bug.
>
> > +{
> > +     int pio_ctrl_val;
> > +     int amap_ctrl_dw;
> > +     u64 size64 =  ~(size-1);
>
> Nit: 1 space before ~ is enough and you should add on both sides of
> the minus sign (-).
>
> I think you should round it though.
>
> u64 mask = (1ULL << fls(size - 1)) - 1;
>
> (mask or whatever you may call it)
>
> > +
> > +     if ((pcie->ib_wins_configured + 1) > pcie->ppio_wins) {
> > +             dev_err(&pcie->pdev->dev,
> > +                     "ERROR: max inbound windows reached !\n");
> > +             return;
> > +     }
> > +
> > +     pio_ctrl_val = csr_readl(pcie, PAB_PEX_PIO_CTRL);
> > +     csr_writel(pcie,
> > +             pio_ctrl_val | (1 << PIO_ENABLE_SHIFT), PAB_PEX_PIO_CTRL);
> > +     amap_ctrl_dw =  read_paged_register(pcie, PAB_PEX_AMAP_CTRL(win_num));
> > +     amap_ctrl_dw = (amap_ctrl_dw | (type << AMAP_CTRL_TYPE_SHIFT));
> > +     amap_ctrl_dw = (amap_ctrl_dw | (1 << AMAP_CTRL_EN_SHIFT));
> > +
> > +     write_paged_register(pcie, amap_ctrl_dw | lower_32_bits(size64),
> > +                             PAB_PEX_AMAP_CTRL(win_num));
> > +
> > +     write_paged_register(pcie, upper_32_bits(size64),
> > +                             PAB_EXT_PEX_AMAP_SIZEN(win_num));
> > +
> > +     write_paged_register(pcie, pci_addr, PAB_PEX_AMAP_AXI_WIN(win_num));
> > +     write_paged_register(pcie, pci_addr, PAB_PEX_AMAP_PEX_WIN_L(win_num));
> > +     write_paged_register(pcie, 0, PAB_PEX_AMAP_PEX_WIN_H(win_num));
> > +}
> > +
> > +/*
> > + * routine to program the outbound windows
> > + */
> > +static void program_ob_windows(struct mobiveil_pcie *pcie, int win_num,
> > +             u64 cpu_addr, u64 pci_addr, u32 config_io_bit,
> > +             int size)
>
> You have a funny way of wrapping lines, even when that's not needed,
> as in the last line.
>
> > +{
> > +
> > +     u32 value, type;
> > +     u64 size64 =  ~(size-1);
>
> See above.
>
> > +     if ((pcie->ob_wins_configured + 1) > pcie->apio_wins) {
> > +             dev_err(&pcie->pdev->dev,
> > +                     "ERROR: max outbound windows reached !\n");
> > +             return;
> > +     }
> > +
> > +     /*
> > +      * program Enable Bit to 1, Type Bit to (00) base 2, AXI Window Size Bit
> > +      * to 4 KB in PAB_AXI_AMAP_CTRL register
> > +      */
> > +     type = config_io_bit;
> > +     value = csr_readl(pcie, PAB_AXI_AMAP_CTRL(win_num));
> > +     csr_writel(pcie,
> > +                     1 << WIN_ENABLE_SHIFT |
>
> What fits in a line should stay in a line.
>
> > +                     type << WIN_TYPE_SHIFT |
> > +                     lower_32_bits(size64),
> > +                     PAB_AXI_AMAP_CTRL(win_num));
>
> Here:
>         csr_writel(pcie, 1 << WIN_ENABLE_SHIFT |
>                         type << WIN_TYPE_SHIFT |
>                         lower_32_bits(size64), PAB_AXI_AMAP_CTRL(win_num));
> > +     write_paged_register(pcie, upper_32_bits(size64),
> > +                             PAB_EXT_AXI_AMAP_SIZE(win_num));
> > +
> > +     /*
> > +      * program AXI window base with appropriate value in
> > +      * PAB_AXI_AMAP_AXI_WIN0 register
> > +      */
> > +     value = csr_readl(pcie, PAB_AXI_AMAP_AXI_WIN(win_num));
> > +     csr_writel(pcie,
> > +                     cpu_addr >>
> AXI_WINDOW_BASE_SHIFT <<
> > +                     AXI_WINDOW_BASE_SHIFT,
> PAB_AXI_AMAP_AXI_WIN(win_num));
>
> Can you explain to me what this >> << is there for ?
>
Thats bad way of aligning the cpu_addr upto *_BASE_SHIFT

lsb bits now it seems, we'll modify it to
something better like : & (~AXI_WINDOW_ALIGN_MASK) in next patch

> > +     value = csr_readl(pcie, PAB_AXI_AMAP_PEX_WIN_H(win_num));
> > +
> > +     csr_writel(pcie, lower_32_bits(pci_addr),
> > +                     PAB_AXI_AMAP_PEX_WIN_L(win_num));
> > +     csr_writel(pcie, upper_32_bits(pci_addr),
> > +                     PAB_AXI_AMAP_PEX_WIN_H(win_num));
> > +
> > +     pcie->ob_wins_configured++;
> > +}
> > +
> > +static int mobiveil_bringup_link(struct mobiveil_pcie *pcie)
> > +{
> > +     int retries;
> > +
> > +     /* check if the link is up or not */
> > +     for (retries = 0; retries < LINK_WAIT_MAX_RETRIES; retries++) {
> > +             if (mobiveil_pcie_link_up(pcie))
> > +                     return 0;
> > +
> > +             usleep_range(LINK_WAIT_MIN, LINK_WAIT_MAX);
> > +     }
> > +     dev_err(&pcie->pdev->dev, "link never came up\n");
> > +     return -ETIMEDOUT;
> > +}
> > +
> > +static int mobiveil_host_init(struct mobiveil_pcie *pcie)
> > +{
> > +     u32 value;
> > +     u32 type = 0;
> > +     u32 pab_ctrl;
>
> Why do you need three lines for the same type ?
>
> > +     int err;
> > +     struct resource_entry *win, *tmp;
> > +
> > +     err = mobiveil_bringup_link(pcie);
> > +     if (err) {
> > +             dev_info(&pcie->pdev->dev, "link bring-up failed\n");
> > +             return err;
> > +     }
> > +
> > +     /*
> > +      * program Bus Master Enable Bit in Command Register in PAB Config
> > +      * Space
> > +      */
> > +     value = csr_readl(pcie, PCI_COMMAND);
> > +     csr_writel(pcie, value | PCI_COMMAND_IO | PCI_COMMAND_MEMORY |
> > +             PCI_COMMAND_MASTER,     PCI_COMMAND);
>                                    ^
>
> Tab not needed, just a space.
>
> > +     /*
> > +      * program PIO Enable Bit to 1 (and PEX PIO Enable to 1) in PAB_CTRL
> > +      * register
> > +      */
> > +     pab_ctrl = csr_readl(pcie, PAB_CTRL);
> > +     csr_writel(pcie, pab_ctrl | (1 << AMBA_PIO_ENABLE_SHIFT) |
> > +             (1 << PEX_PIO_ENABLE_SHIFT),
> > +             PAB_CTRL);
> > +
> > +     csr_writel(pcie, (PAB_INTP_INTX_MASK | PAB_INTP_MSI_MASK),
> > +             PAB_INTP_AMBA_MISC_ENB);
> > +
> > +     /* program PIO Enable Bit to 1 and Config Window Enable Bit to 1 in
> > +      * PAB_AXI_PIO_CTRL Register
> > +      */
> > +     value = csr_readl(pcie, PAB_AXI_PIO_CTRL);
> > +     csr_writel(pcie, value | APIO_EN_MASK, PAB_AXI_PIO_CTRL);
> > +
> > +     /*
> > +      * we'll program one outbound window for config reads and
> > +      * another default inbound window for all the upstream traffic
> > +      * rest of the outbound windows will be configured according to
> > +      * the "ranges" field defined in device tree
> > +      */
> > +
> > +     /* config outbound translation window */
> > +     program_ob_windows(pcie, pcie->ob_wins_configured,
> > +                     pcie->ob_io_res->start, 0, CFG_WINDOW_TYPE,
> > +                     resource_size(pcie->ob_io_res));
> > +
> > +     /* memory inbound  translation window */
> > +     program_ib_windows(pcie, WIN_NUM_1, 0, MEM_WINDOW_TYPE, IB_WIN_SIZE);
> > +
> > +     /* Get the I/O and memory ranges from DT */
> > +     resource_list_for_each_entry_safe(win, tmp, &pcie->resources) {
> > +             type = 0;
> > +             if (resource_type(win->res) == IORESOURCE_MEM)
> > +                     type = MEM_WINDOW_TYPE;
> > +             if (resource_type(win->res) == IORESOURCE_IO)
> > +                     type = IO_WINDOW_TYPE;
> > +             if (type) {
> > +                     /* configure outbound translation window */
> > +                     program_ob_windows(pcie, pcie->ob_wins_configured,
> > +                             win->res->start, 0, type,
> > +                             resource_size(win->res));
> > +             }
> > +     }
> > +
> > +     return err;
> > +}
> > +
> > +static void mobiveil_mask_intx_irq(struct irq_data *data)
> > +{
> > +     struct irq_desc *desc = irq_to_desc(data->irq);
> > +     struct mobiveil_pcie *pcie;
> > +     unsigned long flags;
> > +     u32 mask;
> > +     u32 shifted_val;
>
> All u32 variables in one line please.
>
> > +     pcie = irq_desc_get_chip_data(desc);
> > +     mask = 1 << ((data->hwirq + PAB_INTA_POS) - 1);
> > +     raw_spin_lock_irqsave(&pcie->intx_mask_lock, flags);
> > +     shifted_val = csr_readl(pcie, PAB_INTP_AMBA_MISC_ENB);
> > +     csr_writel(pcie, (shifted_val & (~mask)), PAB_INTP_AMBA_MISC_ENB);
> > +     raw_spin_unlock_irqrestore(&pcie->intx_mask_lock, flags);
> > +}
> > +
> > +static void mobiveil_unmask_intx_irq(struct irq_data *data)
> > +{
> > +     struct irq_desc *desc = irq_to_desc(data->irq);
> > +     struct mobiveil_pcie *pcie;
> > +     unsigned long flags;
> > +     u32 shifted_val;
> > +     u32 mask;
>
> All u32 in one line.
>
> > +
> > +     pcie = irq_desc_get_chip_data(desc);
> > +     mask = 1 << ((data->hwirq + PAB_INTA_POS) - 1);
> > +     raw_spin_lock_irqsave(&pcie->intx_mask_lock, flags);
> > +     shifted_val = csr_readl(pcie, PAB_INTP_AMBA_MISC_ENB);
> > +     csr_writel(pcie, (shifted_val | mask), PAB_INTP_AMBA_MISC_ENB);
> > +     raw_spin_unlock_irqrestore(&pcie->intx_mask_lock, flags);
> > +}
> > +
> > +static struct irq_chip intx_irq_chip = {
> > +     .name = "mobiveil_pcie:intx",
> > +     .irq_enable = mobiveil_unmask_intx_irq,
> > +     .irq_disable = mobiveil_mask_intx_irq,
> > +     .irq_mask = mobiveil_mask_intx_irq,
> > +     .irq_unmask = mobiveil_unmask_intx_irq,
> > +};
> > +
> > +/* routine to setup the INTx related data */
> > +static int mobiveil_pcie_intx_map(struct irq_domain *domain, unsigned int irq,
> > +             irq_hw_number_t hwirq)
> > +{
> > +     irq_set_chip_and_handler(irq, &intx_irq_chip, handle_simple_irq);
> > +     irq_set_chip_data(irq, domain->host_data);
> > +     return 0;
> > +}
> > +
> > +/* INTx domain operations structure */
> > +static const struct irq_domain_ops intx_domain_ops = {
> > +     .map = mobiveil_pcie_intx_map,
> > +     .xlate =
> pci_irqd_intx_xlate,
>
> I do not think you need this xlate if you follow what's discussed in DT
> bindings.
>
> > +};
> > +
> > +static int mobiveil_pcie_init_irq_domain(struct mobiveil_pcie *pcie)
> > +{
> > +     struct device *dev = &pcie->pdev->dev;
> > +     struct device_node *node = dev->of_node;
> > +     int ret;
> > +
> > +     /* setup INTx */
> > +     pcie->intx_domain = irq_domain_add_linear(node,
> > +                             PCI_NUM_INTX + 1, &intx_domain_ops, pcie);
>
> Remove (+1).
>
> > +     if (!pcie->intx_domain) {
> > +             dev_err(dev, "Failed to get a INTx IRQ domain\n");
> > +             return -ENODEV;
> > +     }
> > +
> > +     raw_spin_lock_init(&pcie->intx_mask_lock);
> > +
> > +     return 0;
> > +}
> > +
> > +static int mobiveil_pcie_probe(struct platform_device *pdev)
> > +{
> > +     struct mobiveil_pcie *pcie;
> > +     struct pci_bus *bus;
> > +     struct pci_bus *child;
> > +     struct pci_host_bridge *bridge;
> > +     struct device *dev = &pdev->dev;
> > +     struct device_node *node = dev->of_node;
> > +     resource_size_t iobase;
> > +     int ret;
> > +
> > +     /* allocate the PCIe port */
> > +     bridge = devm_pci_alloc_host_bridge(dev, sizeof(*pcie));
> > +     if (!bridge)
> > +             return -ENODEV;
> > +
> > +     pcie = pci_host_bridge_priv(bridge);
> > +     if (!pcie)
> > +             return -ENOMEM;
> > +
> > +     pcie->pdev = pdev;
> > +
> > +     ret = mobiveil_pcie_parse_dt(pcie);
> > +     if (ret) {
> > +             dev_err(dev, "Parsing DT failed, ret: %x\n", ret);
> > +             return ret;
> > +     }
> > +
> > +     INIT_LIST_HEAD(&pcie->resources);
> > +
> > +     /* parse the host bridge base addresses from the device tree file */
> > +     ret = of_pci_get_host_bridge_resources(node,
> > +                     0, 0xff, &pcie->resources, &iobase);
> > +     if (ret) {
> > +             dev_err(dev, "Getting bridge resources failed\n");
> > +             return -ENOMEM;
> > +     }
> > +
> > +     /*
> > +      * configure all inbound and outbound windows and prepare the RC for
> > +      * config access
> > +      */
> > +     ret = mobiveil_host_init(pcie);
> > +     if (ret) {
> > +             dev_err(dev, "Failed to initialize host\n");
> > +             goto error;
> > +     }
> > +
> > +     /* fixup for PCIe class register */
> > +     csr_writel(pcie, 0x060402ab, PAB_INTP_AXI_PIO_CLASS);
> > +
> > +     /* initialize the IRQ domains */
> > +     ret = mobiveil_pcie_init_irq_domain(pcie);
> > +     if (ret) {
> > +             dev_err(dev, "Failed creating IRQ Domain\n");
> > +             goto error;
> > +     }
> > +
> > +     ret = devm_request_pci_bus_resources(dev, &pcie->resources);
> > +     if (ret)
> > +             goto error;
> > +
> > +     /* Initialize bridge */
> > +     list_splice_init(&pcie->resources, &bridge->windows);
> > +     bridge->dev.parent = dev;
> > +     bridge->sysdata = pcie;
> > +     bridge->busnr = pcie->root_bus_nr;
> > +     bridge->ops = &mobiveil_pcie_ops;
> > +     bridge->map_irq = of_irq_parse_and_map_pci;
> > +     bridge->swizzle_irq = pci_common_swizzle;
> > +
> > +     /* setup the kernel resources for the newly added PCIe root bus */
> > +     ret = pci_scan_root_bus_bridge(bridge);
> > +     if (ret)
> > +             goto error;
> > +
> > +     bus = bridge->bus;
> > +
> > +     pci_assign_unassigned_bus_resources(bus);
> > +     list_for_each_entry(child, &bus->children, node)
> > +             pcie_bus_configure_settings(child);
> > +     pci_bus_add_devices(bus);
> > +
> > +     platform_set_drvdata(pdev, pcie);
>
> What's this needed for ?
>
> > +     return 0;
> > +error:
> > +     pci_free_resource_list(&pcie->resources);
> > +     return ret;
> > +}
> > +
> > +static const struct of_device_id mobiveil_pcie_of_match[] = {
> > +     {.compatible = "mbvl,gpex40-pcie",},
> > +};
> > +
> > +MODULE_DEVICE_TABLE(of, mobiveil_pcie_of_match);
> > +
> > +static struct platform_driver mobiveil_pcie_driver = {
> > +     .probe = mobiveil_pcie_probe,
> > +     .driver = {
> > +                     .name = "mobiveil-pcie",
> > +                     .of_match_table = mobiveil_pcie_of_match,
> > +                     .suppress_bind_attrs = true,
> > +             },
> > +};
> > +
> > +builtin_platform_driver(mobiveil_pcie_driver);
> > +
> > +MODULE_LICENSE("GPL v2");
> > +MODULE_DESCRIPTION("Mobiveil PCIe host controller driver");
> > +MODULE_AUTHOR("Subrahmanya Lingappa <l.subrahmanya@mobiveil.co.in>");
>
> Thanks,
> Lorenzo


Thanks
Subrahmanya Lingappa March 27, 2018, 12:04 p.m. UTC | #5
Lorenzo,

On Fri, Mar 9, 2018 at 11:18 PM, Lorenzo Pieralisi
<lorenzo.pieralisi@arm.com> wrote:
> On Tue, Feb 27, 2018 at 07:20:24AM -0500, Subrahmanya Lingappa wrote:
>> Adds driver for Mobiveil AXI PCIe Host Bridge Soft IP -
>> GPEX 4.0, a PCIe gen4 IP. This IP has upto 8
>> outbound and inbound windows for the address translation.
>>
>> Signed-off-by: Subrahmanya Lingappa <l.subrahmanya@mobiveil.co.in>
>> Cc: Bjorn Helgaas <bhelgaas@google.com>
>> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
>> Cc: Marc Zyngier <marc.zyngier@arm.com>
>> Cc: linux-pci@vger.kernel.org
>> Cc: devicetree@vger.kernel.org
>> ---
>>  drivers/pci/host/pcie-mobiveil.c | 692 +++++++++++++++++++++++++++++++++++++++
>>  1 file changed, 692 insertions(+)
>>  create mode 100644 drivers/pci/host/pcie-mobiveil.c
>>
>> diff --git a/drivers/pci/host/pcie-mobiveil.c b/drivers/pci/host/pcie-mobiveil.c
>> new file mode 100644
>> index 0000000..4270387
>> --- /dev/null
>> +++ b/drivers/pci/host/pcie-mobiveil.c
>> @@ -0,0 +1,692 @@
>> +/*
>> + * PCIe host controller driver for Mobiveil PCIe Host controller
>> + *
>> + * SPDX-License-Identifier: GPL-2.0
>> + * Copyright (c) 2017 Mobiveil Inc.
>> + * Author: Subrahmanya Lingappa <l.subrahmanya@mobiveil.co.in>
>> + */
>> +
>> +#include <linux/delay.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/init.h>
>
> Nit: swap init.h and interrupt.h, alphabetical order.
>
> [...]
>
>> +/* supported number of interrupts */
>> +#define PCI_NUM_INTX    4
>
> It is already defined in PCI includes, remove it.
>
>> +#define PAB_INTA_POS    5
>                        ^^^^
> This ought to be a tab.
>
>> +/* outbound and inbound window definitions */
>> +#define WIN_NUM_0            0
>> +#define WIN_NUM_1            1
>> +#define CFG_WINDOW_TYPE              0
>> +#define IO_WINDOW_TYPE               1
>> +#define MEM_WINDOW_TYPE              2
>> +#define IB_WIN_SIZE          (256 * 1024 * 1024 * 1024)
>> +#define MAX_PIO_WINDOWS              8
>> +
>> +/* Parameters for the waiting for link up routine */
>> +#define LINK_WAIT_MAX_RETRIES        10
>> +#define LINK_WAIT_MIN                90000
>> +#define LINK_WAIT_MAX                100000
>> +
>> +struct mobiveil_pcie {
>> +     struct platform_device *pdev;
>> +     struct list_head resources;
>> +     void __iomem *config_axi_slave_base;    /* endpoint config base */
>> +     void __iomem *csr_axi_slave_base;   /* root port config base */
>                                         ^^^^
>
> A tab please.
>
>> +     void __iomem *pcie_reg_base;    /* Physical PCIe Controller Base */
> Ditto.
>
>> +     struct irq_domain *intx_domain;
>> +     raw_spinlock_t intx_mask_lock;
>> +     int irq;
>> +     int apio_wins;
>> +     int ppio_wins;
>> +     int ob_wins_configured; /*  configured outbound windows */
>> +     int ib_wins_configured; /*  configured inbound windows */
>> +     struct resource *ob_io_res;
>> +     char root_bus_nr;
>> +};
>> +
>> +static inline void csr_writel(struct mobiveil_pcie *pcie, const u32 value,
>> +             const u32 reg)
>> +{
>> +     writel_relaxed(value, pcie->csr_axi_slave_base + reg);
>> +}
>> +
>> +static inline u32 csr_readl(struct mobiveil_pcie *pcie,      const u32 reg)
>> +{
>> +     return readl_relaxed(pcie->csr_axi_slave_base + reg);
>> +}
>> +
>> +/*
>> + * Routine to check the downstream link status, its recommended to
>> + * check the link status before accessing downstream config resources.
>> + */
>> +static bool mobiveil_pcie_link_up(struct mobiveil_pcie *pcie)
>> +{
>> +     return (csr_readl(pcie, LTSSM_STATUS) &
>> +             LTSSM_STATUS_L0_MASK) == LTSSM_STATUS_L0;
>> +}
>> +
>> +static bool mobiveil_pcie_valid_device(struct pci_bus *bus, unsigned int devfn)
>> +{
>> +     struct mobiveil_pcie *pcie = bus->sysdata;
>> +
>> +     /* Check if link is up when trying to access downstream ports */
>> +     if (bus->number != pcie->root_bus_nr)
>> +             if (!mobiveil_pcie_link_up(pcie))
>
> Do you really need this racy check ? Bjorn wants to remove it
> from other drivers - what happens on surprise link loss on
> your platform ?
>
link below gave multiple reasons why we might need this; looks like no
common consensus was reached.
can we keep it with the comment ?
https://www.spinics.net/lists/linux-pci/msg67910.html
>> +                     return false;
>> +
>> +     /* Only one device down on each root port */
>> +     if ((bus->number == pcie->root_bus_nr) && (devfn > 0))
>> +             return false;
>> +
>> +     /*
>> +      * Do not read more than one device on the bus directly
>> +      * attached to RC
>> +      */
>> +     if ((bus->primary == pcie->root_bus_nr) && (devfn > 0))
>> +             return false;
>> +
>> +     return true;
>> +}
>> +
>> +/*
>> + * mobiveil_pcie_map_bus - routine to get the configuration base of either
>> + * root port or endpoint
>> + */
>> +static void __iomem *mobiveil_pcie_map_bus(struct pci_bus *bus,
>> +                                     unsigned int devfn, int where)
>> +{
>> +     struct mobiveil_pcie *pcie = bus->sysdata;
>> +
>> +     if (!mobiveil_pcie_valid_device(bus, devfn))
>> +             return NULL;
>> +
>> +     if (bus->number == pcie->root_bus_nr) {
>> +             /* RC config access */
>> +             return pcie->csr_axi_slave_base + where;
>> +     } else {
>> +             /*
>> +              * EP config access (in Config/APIO space)
>> +              * Program PEX Address base (31..16 bits) with appropriate value
>> +              * (BDF) in PAB_AXI_AMAP_PEX_WIN_L0 Register.
>> +              * Relies on pci_lock serialization
>> +              */
>> +             csr_writel(pcie,
>> +                     bus->number << PAB_BUS_SHIFT |
>> +                     PCI_SLOT(devfn) << PAB_DEVICE_SHIFT |
>> +                     PCI_FUNC(devfn) << PAB_FUNCTION_SHIFT,
>> +                     PAB_AXI_AMAP_PEX_WIN_L(WIN_NUM_0));
>> +             return pcie->config_axi_slave_base + where;
>> +     }
>> +}
>> +
>> +static struct pci_ops mobiveil_pcie_ops = {
>> +     .map_bus = mobiveil_pcie_map_bus,
>> +     .read = pci_generic_config_read,
>> +     .write = pci_generic_config_write,
>> +};
>> +
>> +static void mobiveil_pcie_isr(struct irq_desc *desc)
>> +{
>> +     struct irq_chip *chip = irq_desc_get_chip(desc);
>> +     struct mobiveil_pcie *pcie = irq_desc_get_handler_data(desc);
>> +     struct device *dev = &pcie->pdev->dev;
>> +     unsigned long shifted_status;
>> +     u32 bit, virq;
>> +     u32 val, mask;
>
> Nit: why two lines for same type.
>
>> +     /*
>> +      * The core provides a single interrupt for both INTx/MSI messages.
>> +      * So we'll read both INTx and MSI status
>
> Add a comment for INTX and update it in the next patch. This patch
> only deals with INTX and the comment should reflect that.
>
>> +      */
>> +
>> +     chained_irq_enter(chip, desc);
>> +
>> +     /* read INTx status */
>> +     val = csr_readl(pcie, PAB_INTP_AMBA_MISC_STAT);
>> +     mask = csr_readl(pcie, PAB_INTP_AMBA_MISC_ENB);
>> +     intr_status = val & mask;
>> +
>> +     /* Handle INTx */
>> +     if (intr_status & PAB_INTP_INTX_MASK) {
>> +             shifted_status = csr_readl(pcie, PAB_INTP_AMBA_MISC_STAT) >>
>> +                     PAB_INTA_POS;
>> +             do {
>> +                     for_each_set_bit(bit, &shifted_status, PCI_NUM_INTX) {
>> +                             virq = irq_find_mapping(pcie->intx_domain,
>> +                                             bit + 1);
>
> It must be bit, not bit + 1. See DT bindings comment.
>
>> +                             if (virq)
>> +                                     generic_handle_irq(virq);
>> +                             else
>> +                                     dev_err_ratelimited(dev,
>> +                                             "unexpected IRQ, INT%d\n", bit);
>> +
>> +                             /* clear interrupt */
>> +                             csr_writel(pcie, shifted_status << PAB_INTA_POS,
>> +                                             PAB_INTP_AMBA_MISC_STAT);
>> +                     }
>> +             } while ((shifted_status >>  PAB_INTA_POS) != 0);
>> +     }
>> +
>> +     /* Clear the interrupt status */
>> +     csr_writel(pcie, intr_status, PAB_INTP_AMBA_MISC_STAT);
>> +     chained_irq_exit(chip, desc);
>> +}
>> +
>> +static int mobiveil_pcie_parse_dt(struct mobiveil_pcie *pcie)
>> +{
>> +     struct device *dev = &pcie->pdev->dev;
>> +     struct platform_device *pdev = pcie->pdev;
>> +     struct device_node *node = dev->of_node;
>> +     struct resource *res;
>> +     const char *type;
>> +
>> +     type = of_get_property(node, "device_type", NULL);
>> +     if (!type || strcmp(type, "pci")) {
>> +             dev_err(dev, "invalid \"device_type\" %s\n", type);
>> +             return -EINVAL;
>> +     }
>> +
>> +     /* map config resource */
>> +     res = platform_get_resource_byname(pdev,
>> +             IORESOURCE_MEM, "config_axi_slave");
>
> What can fit in a line should stay in a line, so update this wrapping.
>
>         res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
>                                            "config_axi_slave");
>
>> +     pcie->config_axi_slave_base = devm_pci_remap_cfg_resource(dev, res);
>> +     if (IS_ERR(pcie->config_axi_slave_base))
>> +             return PTR_ERR(pcie->config_axi_slave_base);
>> +     pcie->ob_io_res = res;
>> +
>> +     /* map csr resource */
>> +     res = platform_get_resource_byname(pdev,
>> +             IORESOURCE_MEM, "csr_axi_slave");
>
>         res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
>                                            "csr_axi_slave");
>
>> +     pcie->csr_axi_slave_base = devm_pci_remap_cfg_resource(dev, res);
>> +     if (IS_ERR(pcie->csr_axi_slave_base))
>> +             return PTR_ERR(pcie->csr_axi_slave_base);
>> +     pcie->pcie_reg_base = res->start;
>> +
>> +     /* read the number of windows requested */
>> +     if (of_property_read_u32(node, "apio-wins", &pcie->apio_wins))
>> +             pcie->apio_wins = MAX_PIO_WINDOWS;
>> +
>> +     if (of_property_read_u32(node, "ppio-wins", &pcie->ppio_wins))
>> +             pcie->ppio_wins = MAX_PIO_WINDOWS;
>> +
>> +     pcie->irq = platform_get_irq(pdev, 0);
>> +     if (pcie->irq <= 0) {
>> +             dev_err(dev, "failed to map IRQ: %d\n", pcie->irq);
>> +             return -ENODEV;
>> +     }
>> +
>> +     irq_set_chained_handler_and_data(pcie->irq, mobiveil_pcie_isr, pcie);
>> +
>> +     return 0;
>> +}
>> +
>> +/*
>> + * select_paged_register - routine to access paged register of root complex
>> + *
>> + * registers of RC are paged, for this scheme to work
>> + * extracted higher 6 bits of the offset will be written to pg_sel
>> + * field of PAB_CTRL register and rest of the lower 10 bits enabled with
>> + * PAGE_SEL_EN are used as offset of the register.
>> + *
>> + */
>> +static void select_paged_register(struct mobiveil_pcie *pcie, u32 offset)
>> +{
>> +     int pab_ctrl_dw, pg_sel;
>> +
>> +     /* clear pg_sel field */
>> +     pab_ctrl_dw = csr_readl(pcie, PAB_CTRL);
>> +     pab_ctrl_dw = (pab_ctrl_dw & ~(PAGE_SEL_MASK << PAGE_SEL_SHIFT));
>> +
>> +     /* set pg_sel field */
>> +     pg_sel = (offset >> PAGE_SEL_OFFSET_SHIFT) & PAGE_SEL_MASK;
>> +     pab_ctrl_dw |= ((pg_sel << PAGE_SEL_SHIFT));
>> +     csr_writel(pcie, pab_ctrl_dw, PAB_CTRL);
>> +}
>> +
>> +static void write_paged_register(struct mobiveil_pcie *pcie,
>> +             u32 val, u32 offset)
>> +{
>> +     u32 off = (offset & PAGE_LO_MASK) | PAGE_SEL_EN;
>> +
>> +     select_paged_register(pcie, offset);
>> +     csr_writel(pcie, val, off);
>> +}
>> +
>> +static u32 read_paged_register(struct mobiveil_pcie *pcie, u32 offset)
>> +{
>> +     u32 off = (offset & PAGE_LO_MASK) | PAGE_SEL_EN;
>> +
>> +     select_paged_register(pcie, offset);
>> +     return csr_readl(pcie, off);
>> +}
>> +
>> +static void program_ib_windows(struct mobiveil_pcie *pcie, int win_num,
>> +             int pci_addr, u32 type, int size)
>
> size must certainly not be a signed int and must be u64, for this reason
> current windows are truncated if I am not mistaken so this is a bug.
>
>> +{
>> +     int pio_ctrl_val;
>> +     int amap_ctrl_dw;
>> +     u64 size64 =  ~(size-1);
>
> Nit: 1 space before ~ is enough and you should add on both sides of
> the minus sign (-).
>
> I think you should round it though.
>
> u64 mask = (1ULL << fls(size - 1)) - 1;
>
> (mask or whatever you may call it)
>
>> +
>> +     if ((pcie->ib_wins_configured + 1) > pcie->ppio_wins) {
>> +             dev_err(&pcie->pdev->dev,
>> +                     "ERROR: max inbound windows reached !\n");
>> +             return;
>> +     }
>> +
>> +     pio_ctrl_val = csr_readl(pcie, PAB_PEX_PIO_CTRL);
>> +     csr_writel(pcie,
>> +             pio_ctrl_val | (1 << PIO_ENABLE_SHIFT), PAB_PEX_PIO_CTRL);
>> +     amap_ctrl_dw =  read_paged_register(pcie, PAB_PEX_AMAP_CTRL(win_num));
>> +     amap_ctrl_dw = (amap_ctrl_dw | (type << AMAP_CTRL_TYPE_SHIFT));
>> +     amap_ctrl_dw = (amap_ctrl_dw | (1 << AMAP_CTRL_EN_SHIFT));
>> +
>> +     write_paged_register(pcie, amap_ctrl_dw | lower_32_bits(size64),
>> +                             PAB_PEX_AMAP_CTRL(win_num));
>> +
>> +     write_paged_register(pcie, upper_32_bits(size64),
>> +                             PAB_EXT_PEX_AMAP_SIZEN(win_num));
>> +
>> +     write_paged_register(pcie, pci_addr, PAB_PEX_AMAP_AXI_WIN(win_num));
>> +     write_paged_register(pcie, pci_addr, PAB_PEX_AMAP_PEX_WIN_L(win_num));
>> +     write_paged_register(pcie, 0, PAB_PEX_AMAP_PEX_WIN_H(win_num));
>> +}
>> +
>> +/*
>> + * routine to program the outbound windows
>> + */
>> +static void program_ob_windows(struct mobiveil_pcie *pcie, int win_num,
>> +             u64 cpu_addr, u64 pci_addr, u32 config_io_bit,
>> +             int size)
>
> You have a funny way of wrapping lines, even when that's not needed,
> as in the last line.
>
>> +{
>> +
>> +     u32 value, type;
>> +     u64 size64 =  ~(size-1);
>
> See above.
>
>> +     if ((pcie->ob_wins_configured + 1) > pcie->apio_wins) {
>> +             dev_err(&pcie->pdev->dev,
>> +                     "ERROR: max outbound windows reached !\n");
>> +             return;
>> +     }
>> +
>> +     /*
>> +      * program Enable Bit to 1, Type Bit to (00) base 2, AXI Window Size Bit
>> +      * to 4 KB in PAB_AXI_AMAP_CTRL register
>> +      */
>> +     type = config_io_bit;
>> +     value = csr_readl(pcie, PAB_AXI_AMAP_CTRL(win_num));
>> +     csr_writel(pcie,
>> +                     1 << WIN_ENABLE_SHIFT |
>
> What fits in a line should stay in a line.
>
>> +                     type << WIN_TYPE_SHIFT |
>> +                     lower_32_bits(size64),
>> +                     PAB_AXI_AMAP_CTRL(win_num));
>
> Here:
>         csr_writel(pcie, 1 << WIN_ENABLE_SHIFT |
>                         type << WIN_TYPE_SHIFT |
>                         lower_32_bits(size64), PAB_AXI_AMAP_CTRL(win_num));
>> +     write_paged_register(pcie, upper_32_bits(size64),
>> +                             PAB_EXT_AXI_AMAP_SIZE(win_num));
>> +
>> +     /*
>> +      * program AXI window base with appropriate value in
>> +      * PAB_AXI_AMAP_AXI_WIN0 register
>> +      */
>> +     value = csr_readl(pcie, PAB_AXI_AMAP_AXI_WIN(win_num));
>> +     csr_writel(pcie,
>> +                     cpu_addr >> AXI_WINDOW_BASE_SHIFT <<
>> +                     AXI_WINDOW_BASE_SHIFT, PAB_AXI_AMAP_AXI_WIN(win_num));
>
> Can you explain to me what this >> << is there for ?
>
>> +     value = csr_readl(pcie, PAB_AXI_AMAP_PEX_WIN_H(win_num));
>> +
>> +     csr_writel(pcie, lower_32_bits(pci_addr),
>> +                     PAB_AXI_AMAP_PEX_WIN_L(win_num));
>> +     csr_writel(pcie, upper_32_bits(pci_addr),
>> +                     PAB_AXI_AMAP_PEX_WIN_H(win_num));
>> +
>> +     pcie->ob_wins_configured++;
>> +}
>> +
>> +static int mobiveil_bringup_link(struct mobiveil_pcie *pcie)
>> +{
>> +     int retries;
>> +
>> +     /* check if the link is up or not */
>> +     for (retries = 0; retries < LINK_WAIT_MAX_RETRIES; retries++) {
>> +             if (mobiveil_pcie_link_up(pcie))
>> +                     return 0;
>> +
>> +             usleep_range(LINK_WAIT_MIN, LINK_WAIT_MAX);
>> +     }
>> +     dev_err(&pcie->pdev->dev, "link never came up\n");
>> +     return -ETIMEDOUT;
>> +}
>> +
>> +static int mobiveil_host_init(struct mobiveil_pcie *pcie)
>> +{
>> +     u32 value;
>> +     u32 type = 0;
>> +     u32 pab_ctrl;
>
> Why do you need three lines for the same type ?
>
>> +     int err;
>> +     struct resource_entry *win, *tmp;
>> +
>> +     err = mobiveil_bringup_link(pcie);
>> +     if (err) {
>> +             dev_info(&pcie->pdev->dev, "link bring-up failed\n");
>> +             return err;
>> +     }
>> +
>> +     /*
>> +      * program Bus Master Enable Bit in Command Register in PAB Config
>> +      * Space
>> +      */
>> +     value = csr_readl(pcie, PCI_COMMAND);
>> +     csr_writel(pcie, value | PCI_COMMAND_IO | PCI_COMMAND_MEMORY |
>> +             PCI_COMMAND_MASTER,     PCI_COMMAND);
>                                    ^
>
> Tab not needed, just a space.
>
>> +     /*
>> +      * program PIO Enable Bit to 1 (and PEX PIO Enable to 1) in PAB_CTRL
>> +      * register
>> +      */
>> +     pab_ctrl = csr_readl(pcie, PAB_CTRL);
>> +     csr_writel(pcie, pab_ctrl | (1 << AMBA_PIO_ENABLE_SHIFT) |
>> +             (1 << PEX_PIO_ENABLE_SHIFT),
>> +             PAB_CTRL);
>> +
>> +     csr_writel(pcie, (PAB_INTP_INTX_MASK | PAB_INTP_MSI_MASK),
>> +             PAB_INTP_AMBA_MISC_ENB);
>> +
>> +     /* program PIO Enable Bit to 1 and Config Window Enable Bit to 1 in
>> +      * PAB_AXI_PIO_CTRL Register
>> +      */
>> +     value = csr_readl(pcie, PAB_AXI_PIO_CTRL);
>> +     csr_writel(pcie, value | APIO_EN_MASK, PAB_AXI_PIO_CTRL);
>> +
>> +     /*
>> +      * we'll program one outbound window for config reads and
>> +      * another default inbound window for all the upstream traffic
>> +      * rest of the outbound windows will be configured according to
>> +      * the "ranges" field defined in device tree
>> +      */
>> +
>> +     /* config outbound translation window */
>> +     program_ob_windows(pcie, pcie->ob_wins_configured,
>> +                     pcie->ob_io_res->start, 0, CFG_WINDOW_TYPE,
>> +                     resource_size(pcie->ob_io_res));
>> +
>> +     /* memory inbound  translation window */
>> +     program_ib_windows(pcie, WIN_NUM_1, 0, MEM_WINDOW_TYPE, IB_WIN_SIZE);
>> +
>> +     /* Get the I/O and memory ranges from DT */
>> +     resource_list_for_each_entry_safe(win, tmp, &pcie->resources) {
>> +             type = 0;
>> +             if (resource_type(win->res) == IORESOURCE_MEM)
>> +                     type = MEM_WINDOW_TYPE;
>> +             if (resource_type(win->res) == IORESOURCE_IO)
>> +                     type = IO_WINDOW_TYPE;
>> +             if (type) {
>> +                     /* configure outbound translation window */
>> +                     program_ob_windows(pcie, pcie->ob_wins_configured,
>> +                             win->res->start, 0, type,
>> +                             resource_size(win->res));
>> +             }
>> +     }
>> +
>> +     return err;
>> +}
>> +
>> +static void mobiveil_mask_intx_irq(struct irq_data *data)
>> +{
>> +     struct irq_desc *desc = irq_to_desc(data->irq);
>> +     struct mobiveil_pcie *pcie;
>> +     unsigned long flags;
>> +     u32 mask;
>> +     u32 shifted_val;
>
> All u32 variables in one line please.
>
>> +     pcie = irq_desc_get_chip_data(desc);
>> +     mask = 1 << ((data->hwirq + PAB_INTA_POS) - 1);
>> +     raw_spin_lock_irqsave(&pcie->intx_mask_lock, flags);
>> +     shifted_val = csr_readl(pcie, PAB_INTP_AMBA_MISC_ENB);
>> +     csr_writel(pcie, (shifted_val & (~mask)), PAB_INTP_AMBA_MISC_ENB);
>> +     raw_spin_unlock_irqrestore(&pcie->intx_mask_lock, flags);
>> +}
>> +
>> +static void mobiveil_unmask_intx_irq(struct irq_data *data)
>> +{
>> +     struct irq_desc *desc = irq_to_desc(data->irq);
>> +     struct mobiveil_pcie *pcie;
>> +     unsigned long flags;
>> +     u32 shifted_val;
>> +     u32 mask;
>
> All u32 in one line.
>
>> +
>> +     pcie = irq_desc_get_chip_data(desc);
>> +     mask = 1 << ((data->hwirq + PAB_INTA_POS) - 1);
>> +     raw_spin_lock_irqsave(&pcie->intx_mask_lock, flags);
>> +     shifted_val = csr_readl(pcie, PAB_INTP_AMBA_MISC_ENB);
>> +     csr_writel(pcie, (shifted_val | mask), PAB_INTP_AMBA_MISC_ENB);
>> +     raw_spin_unlock_irqrestore(&pcie->intx_mask_lock, flags);
>> +}
>> +
>> +static struct irq_chip intx_irq_chip = {
>> +     .name = "mobiveil_pcie:intx",
>> +     .irq_enable = mobiveil_unmask_intx_irq,
>> +     .irq_disable = mobiveil_mask_intx_irq,
>> +     .irq_mask = mobiveil_mask_intx_irq,
>> +     .irq_unmask = mobiveil_unmask_intx_irq,
>> +};
>> +
>> +/* routine to setup the INTx related data */
>> +static int mobiveil_pcie_intx_map(struct irq_domain *domain, unsigned int irq,
>> +             irq_hw_number_t hwirq)
>> +{
>> +     irq_set_chip_and_handler(irq, &intx_irq_chip, handle_simple_irq);
>> +     irq_set_chip_data(irq, domain->host_data);
>> +     return 0;
>> +}
>> +
>> +/* INTx domain operations structure */
>> +static const struct irq_domain_ops intx_domain_ops = {
>> +     .map = mobiveil_pcie_intx_map,
>> +     .xlate = pci_irqd_intx_xlate,
>
> I do not think you need this xlate if you follow what's discussed in DT
> bindings.
>
>> +};
>> +
>> +static int mobiveil_pcie_init_irq_domain(struct mobiveil_pcie *pcie)
>> +{
>> +     struct device *dev = &pcie->pdev->dev;
>> +     struct device_node *node = dev->of_node;
>> +     int ret;
>> +
>> +     /* setup INTx */
>> +     pcie->intx_domain = irq_domain_add_linear(node,
>> +                             PCI_NUM_INTX + 1, &intx_domain_ops, pcie);
>
> Remove (+1).
>
>> +     if (!pcie->intx_domain) {
>> +             dev_err(dev, "Failed to get a INTx IRQ domain\n");
>> +             return -ENODEV;
>> +     }
>> +
>> +     raw_spin_lock_init(&pcie->intx_mask_lock);
>> +
>> +     return 0;
>> +}
>> +
>> +static int mobiveil_pcie_probe(struct platform_device *pdev)
>> +{
>> +     struct mobiveil_pcie *pcie;
>> +     struct pci_bus *bus;
>> +     struct pci_bus *child;
>> +     struct pci_host_bridge *bridge;
>> +     struct device *dev = &pdev->dev;
>> +     struct device_node *node = dev->of_node;
>> +     resource_size_t iobase;
>> +     int ret;
>> +
>> +     /* allocate the PCIe port */
>> +     bridge = devm_pci_alloc_host_bridge(dev, sizeof(*pcie));
>> +     if (!bridge)
>> +             return -ENODEV;
>> +
>> +     pcie = pci_host_bridge_priv(bridge);
>> +     if (!pcie)
>> +             return -ENOMEM;
>> +
>> +     pcie->pdev = pdev;
>> +
>> +     ret = mobiveil_pcie_parse_dt(pcie);
>> +     if (ret) {
>> +             dev_err(dev, "Parsing DT failed, ret: %x\n", ret);
>> +             return ret;
>> +     }
>> +
>> +     INIT_LIST_HEAD(&pcie->resources);
>> +
>> +     /* parse the host bridge base addresses from the device tree file */
>> +     ret = of_pci_get_host_bridge_resources(node,
>> +                     0, 0xff, &pcie->resources, &iobase);
>> +     if (ret) {
>> +             dev_err(dev, "Getting bridge resources failed\n");
>> +             return -ENOMEM;
>> +     }
>> +
>> +     /*
>> +      * configure all inbound and outbound windows and prepare the RC for
>> +      * config access
>> +      */
>> +     ret = mobiveil_host_init(pcie);
>> +     if (ret) {
>> +             dev_err(dev, "Failed to initialize host\n");
>> +             goto error;
>> +     }
>> +
>> +     /* fixup for PCIe class register */
>> +     csr_writel(pcie, 0x060402ab, PAB_INTP_AXI_PIO_CLASS);
>> +
>> +     /* initialize the IRQ domains */
>> +     ret = mobiveil_pcie_init_irq_domain(pcie);
>> +     if (ret) {
>> +             dev_err(dev, "Failed creating IRQ Domain\n");
>> +             goto error;
>> +     }
>> +
>> +     ret = devm_request_pci_bus_resources(dev, &pcie->resources);
>> +     if (ret)
>> +             goto error;
>> +
>> +     /* Initialize bridge */
>> +     list_splice_init(&pcie->resources, &bridge->windows);
>> +     bridge->dev.parent = dev;
>> +     bridge->sysdata = pcie;
>> +     bridge->busnr = pcie->root_bus_nr;
>> +     bridge->ops = &mobiveil_pcie_ops;
>> +     bridge->map_irq = of_irq_parse_and_map_pci;
>> +     bridge->swizzle_irq = pci_common_swizzle;
>> +
>> +     /* setup the kernel resources for the newly added PCIe root bus */
>> +     ret = pci_scan_root_bus_bridge(bridge);
>> +     if (ret)
>> +             goto error;
>> +
>> +     bus = bridge->bus;
>> +
>> +     pci_assign_unassigned_bus_resources(bus);
>> +     list_for_each_entry(child, &bus->children, node)
>> +             pcie_bus_configure_settings(child);
>> +     pci_bus_add_devices(bus);
>> +
>> +     platform_set_drvdata(pdev, pcie);
>
> What's this needed for ?
>
>> +     return 0;
>> +error:
>> +     pci_free_resource_list(&pcie->resources);
>> +     return ret;
>> +}
>> +
>> +static const struct of_device_id mobiveil_pcie_of_match[] = {
>> +     {.compatible = "mbvl,gpex40-pcie",},
>> +};
>> +
>> +MODULE_DEVICE_TABLE(of, mobiveil_pcie_of_match);
>> +
>> +static struct platform_driver mobiveil_pcie_driver = {
>> +     .probe = mobiveil_pcie_probe,
>> +     .driver = {
>> +                     .name = "mobiveil-pcie",
>> +                     .of_match_table = mobiveil_pcie_of_match,
>> +                     .suppress_bind_attrs = true,
>> +             },
>> +};
>> +
>> +builtin_platform_driver(mobiveil_pcie_driver);
>> +
>> +MODULE_LICENSE("GPL v2");
>> +MODULE_DESCRIPTION("Mobiveil PCIe host controller driver");
>> +MODULE_AUTHOR("Subrahmanya Lingappa <l.subrahmanya@mobiveil.co.in>");
>
> Thanks,
> Lorenzo
Thanks.
diff mbox

Patch

diff --git a/drivers/pci/host/pcie-mobiveil.c b/drivers/pci/host/pcie-mobiveil.c
new file mode 100644
index 0000000..4270387
--- /dev/null
+++ b/drivers/pci/host/pcie-mobiveil.c
@@ -0,0 +1,692 @@ 
+/*
+ * PCIe host controller driver for Mobiveil PCIe Host controller
+ *
+ * SPDX-License-Identifier: GPL-2.0
+ * Copyright (c) 2017 Mobiveil Inc.
+ * Author: Subrahmanya Lingappa <l.subrahmanya@mobiveil.co.in>
+ */
+
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/init.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>
+#include <linux/of_irq.h>
+#include <linux/of_platform.h>
+#include <linux/of_pci.h>
+#include <linux/pci.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+/* register offsets and bit positions */
+
+/*
+ * translation tables are grouped into windows, each window registers are
+ * grouped into blocks of 4 or 16 registers each
+ */
+#define PAB_REG_BLOCK_SIZE	16
+#define PAB_EXT_REG_BLOCK_SIZE	4
+
+#define PAB_REG_ADDR(offset, win) (offset + (win * PAB_REG_BLOCK_SIZE))
+#define PAB_EXT_REG_ADDR(offset, win) (offset + (win * PAB_EXT_REG_BLOCK_SIZE))
+
+#define LTSSM_STATUS		0x0404
+#define  LTSSM_STATUS_L0_MASK	0x3f
+#define  LTSSM_STATUS_L0	0x2d
+
+#define PAB_CTRL		0x0808
+#define  AMBA_PIO_ENABLE_SHIFT	0
+#define  PEX_PIO_ENABLE_SHIFT	1
+#define  PAGE_SEL_SHIFT		13
+#define  PAGE_SEL_MASK		0x3f
+#define  PAGE_LO_MASK		0x3ff
+#define  PAGE_SEL_EN		0xc00
+#define  PAGE_SEL_OFFSET_SHIFT	10
+
+#define PAB_AXI_PIO_CTRL	0x0840
+#define  APIO_EN_MASK		0xf
+
+#define PAB_PEX_PIO_CTRL	0x08c0
+#define  PIO_ENABLE_SHIFT	0
+
+#define PAB_INTP_AMBA_MISC_ENB	0x0b0c
+#define PAB_INTP_AMBA_MISC_STAT	0x0b1c
+#define  PAB_INTP_INTX_MASK	0x1e0
+
+#define PAB_AXI_AMAP_CTRL(win)	PAB_REG_ADDR(0x0ba0, win)
+#define  WIN_ENABLE_SHIFT	0
+#define  WIN_TYPE_SHIFT		1
+
+#define PAB_EXT_AXI_AMAP_SIZE(win)	PAB_EXT_REG_ADDR(0xbaf0, win)
+
+#define PAB_AXI_AMAP_AXI_WIN(win)	PAB_REG_ADDR(0x0ba4, win)
+#define  AXI_WINDOW_BASE_SHIFT		2
+
+#define PAB_AXI_AMAP_PEX_WIN_L(win)	PAB_REG_ADDR(0x0ba8, win)
+#define  PAB_BUS_SHIFT			24
+#define  PAB_DEVICE_SHIFT		19
+#define  PAB_FUNCTION_SHIFT		16
+
+#define PAB_AXI_AMAP_PEX_WIN_H(win)	PAB_REG_ADDR(0x0bac, win)
+#define PAB_INTP_AXI_PIO_CLASS		0x474
+
+#define PAB_PEX_AMAP_CTRL(win)		PAB_REG_ADDR(0x4ba0, win)
+#define  AMAP_CTRL_EN_SHIFT		0
+#define  AMAP_CTRL_TYPE_SHIFT		1
+
+#define PAB_EXT_PEX_AMAP_SIZEN(win)	PAB_EXT_REG_ADDR(0xbef0, win)
+#define PAB_PEX_AMAP_AXI_WIN(win)	PAB_REG_ADDR(0x4ba4, win)
+#define PAB_PEX_AMAP_PEX_WIN_L(win)	PAB_REG_ADDR(0x4ba8, win)
+#define PAB_PEX_AMAP_PEX_WIN_H(win)	PAB_REG_ADDR(0x4bac, win)
+
+/* supported number of interrupts */
+#define PCI_NUM_INTX    4
+#define PAB_INTA_POS    5
+
+/* outbound and inbound window definitions */
+#define WIN_NUM_0		0
+#define WIN_NUM_1		1
+#define CFG_WINDOW_TYPE		0
+#define IO_WINDOW_TYPE		1
+#define MEM_WINDOW_TYPE		2
+#define IB_WIN_SIZE		(256 * 1024 * 1024 * 1024)
+#define MAX_PIO_WINDOWS		8
+
+/* Parameters for the waiting for link up routine */
+#define LINK_WAIT_MAX_RETRIES	10
+#define LINK_WAIT_MIN		90000
+#define LINK_WAIT_MAX		100000
+
+struct mobiveil_pcie {
+	struct platform_device *pdev;
+	struct list_head resources;
+	void __iomem *config_axi_slave_base;	/* endpoint config base */
+	void __iomem *csr_axi_slave_base;   /* root port config base */
+	void __iomem *pcie_reg_base;    /* Physical PCIe Controller Base */
+	struct irq_domain *intx_domain;
+	raw_spinlock_t intx_mask_lock;
+	int irq;
+	int apio_wins;
+	int ppio_wins;
+	int ob_wins_configured;	/*  configured outbound windows */
+	int ib_wins_configured;	/*  configured inbound windows */
+	struct resource *ob_io_res;
+	char root_bus_nr;
+};
+
+static inline void csr_writel(struct mobiveil_pcie *pcie, const u32 value,
+		const u32 reg)
+{
+	writel_relaxed(value, pcie->csr_axi_slave_base + reg);
+}
+
+static inline u32 csr_readl(struct mobiveil_pcie *pcie,	const u32 reg)
+{
+	return readl_relaxed(pcie->csr_axi_slave_base + reg);
+}
+
+/*
+ * Routine to check the downstream link status, its recommended to
+ * check the link status before accessing downstream config resources.
+ */
+static bool mobiveil_pcie_link_up(struct mobiveil_pcie *pcie)
+{
+	return (csr_readl(pcie, LTSSM_STATUS) &
+		LTSSM_STATUS_L0_MASK) == LTSSM_STATUS_L0;
+}
+
+static bool mobiveil_pcie_valid_device(struct pci_bus *bus, unsigned int devfn)
+{
+	struct mobiveil_pcie *pcie = bus->sysdata;
+
+	/* Check if link is up when trying to access downstream ports */
+	if (bus->number != pcie->root_bus_nr)
+		if (!mobiveil_pcie_link_up(pcie))
+			return false;
+
+	/* Only one device down on each root port */
+	if ((bus->number == pcie->root_bus_nr) && (devfn > 0))
+		return false;
+
+	/*
+	 * Do not read more than one device on the bus directly
+	 * attached to RC
+	 */
+	if ((bus->primary == pcie->root_bus_nr) && (devfn > 0))
+		return false;
+
+	return true;
+}
+
+/*
+ * mobiveil_pcie_map_bus - routine to get the configuration base of either
+ * root port or endpoint
+ */
+static void __iomem *mobiveil_pcie_map_bus(struct pci_bus *bus,
+					unsigned int devfn, int where)
+{
+	struct mobiveil_pcie *pcie = bus->sysdata;
+
+	if (!mobiveil_pcie_valid_device(bus, devfn))
+		return NULL;
+
+	if (bus->number == pcie->root_bus_nr) {
+		/* RC config access */
+		return pcie->csr_axi_slave_base + where;
+	} else {
+		/*
+		 * EP config access (in Config/APIO space)
+		 * Program PEX Address base (31..16 bits) with appropriate value
+		 * (BDF) in PAB_AXI_AMAP_PEX_WIN_L0 Register.
+		 * Relies on pci_lock serialization
+		 */
+		csr_writel(pcie,
+			bus->number << PAB_BUS_SHIFT |
+			PCI_SLOT(devfn) << PAB_DEVICE_SHIFT |
+			PCI_FUNC(devfn) << PAB_FUNCTION_SHIFT,
+			PAB_AXI_AMAP_PEX_WIN_L(WIN_NUM_0));
+		return pcie->config_axi_slave_base + where;
+	}
+}
+
+static struct pci_ops mobiveil_pcie_ops = {
+	.map_bus = mobiveil_pcie_map_bus,
+	.read = pci_generic_config_read,
+	.write = pci_generic_config_write,
+};
+
+static void mobiveil_pcie_isr(struct irq_desc *desc)
+{
+	struct irq_chip *chip = irq_desc_get_chip(desc);
+	struct mobiveil_pcie *pcie = irq_desc_get_handler_data(desc);
+	struct device *dev = &pcie->pdev->dev;
+	unsigned long shifted_status;
+	u32 bit, virq;
+	u32 val, mask;
+
+	/*
+	 * The core provides a single interrupt for both INTx/MSI messages.
+	 * So we'll read both INTx and MSI status
+	 */
+
+	chained_irq_enter(chip, desc);
+
+	/* read INTx status */
+	val = csr_readl(pcie, PAB_INTP_AMBA_MISC_STAT);
+	mask = csr_readl(pcie, PAB_INTP_AMBA_MISC_ENB);
+	intr_status = val & mask;
+
+	/* Handle INTx */
+	if (intr_status & PAB_INTP_INTX_MASK) {
+		shifted_status = csr_readl(pcie, PAB_INTP_AMBA_MISC_STAT) >>
+			PAB_INTA_POS;
+		do {
+			for_each_set_bit(bit, &shifted_status, PCI_NUM_INTX) {
+				virq = irq_find_mapping(pcie->intx_domain,
+						bit + 1);
+				if (virq)
+					generic_handle_irq(virq);
+				else
+					dev_err_ratelimited(dev,
+						"unexpected IRQ, INT%d\n", bit);
+
+				/* clear interrupt */
+				csr_writel(pcie, shifted_status << PAB_INTA_POS,
+						PAB_INTP_AMBA_MISC_STAT);
+			}
+		} while ((shifted_status >>  PAB_INTA_POS) != 0);
+	}
+
+	/* Clear the interrupt status */
+	csr_writel(pcie, intr_status, PAB_INTP_AMBA_MISC_STAT);
+	chained_irq_exit(chip, desc);
+}
+
+static int mobiveil_pcie_parse_dt(struct mobiveil_pcie *pcie)
+{
+	struct device *dev = &pcie->pdev->dev;
+	struct platform_device *pdev = pcie->pdev;
+	struct device_node *node = dev->of_node;
+	struct resource *res;
+	const char *type;
+
+	type = of_get_property(node, "device_type", NULL);
+	if (!type || strcmp(type, "pci")) {
+		dev_err(dev, "invalid \"device_type\" %s\n", type);
+		return -EINVAL;
+	}
+
+	/* map config resource */
+	res = platform_get_resource_byname(pdev,
+		IORESOURCE_MEM, "config_axi_slave");
+	pcie->config_axi_slave_base = devm_pci_remap_cfg_resource(dev, res);
+	if (IS_ERR(pcie->config_axi_slave_base))
+		return PTR_ERR(pcie->config_axi_slave_base);
+	pcie->ob_io_res = res;
+
+	/* map csr resource */
+	res = platform_get_resource_byname(pdev,
+		IORESOURCE_MEM, "csr_axi_slave");
+	pcie->csr_axi_slave_base = devm_pci_remap_cfg_resource(dev, res);
+	if (IS_ERR(pcie->csr_axi_slave_base))
+		return PTR_ERR(pcie->csr_axi_slave_base);
+	pcie->pcie_reg_base = res->start;
+
+	/* read the number of windows requested */
+	if (of_property_read_u32(node, "apio-wins", &pcie->apio_wins))
+		pcie->apio_wins = MAX_PIO_WINDOWS;
+
+	if (of_property_read_u32(node, "ppio-wins", &pcie->ppio_wins))
+		pcie->ppio_wins = MAX_PIO_WINDOWS;
+
+	pcie->irq = platform_get_irq(pdev, 0);
+	if (pcie->irq <= 0) {
+		dev_err(dev, "failed to map IRQ: %d\n", pcie->irq);
+		return -ENODEV;
+	}
+
+	irq_set_chained_handler_and_data(pcie->irq, mobiveil_pcie_isr, pcie);
+
+	return 0;
+}
+
+/*
+ * select_paged_register - routine to access paged register of root complex
+ *
+ * registers of RC are paged, for this scheme to work
+ * extracted higher 6 bits of the offset will be written to pg_sel
+ * field of PAB_CTRL register and rest of the lower 10 bits enabled with
+ * PAGE_SEL_EN are used as offset of the register.
+ *
+ */
+static void select_paged_register(struct mobiveil_pcie *pcie, u32 offset)
+{
+	int pab_ctrl_dw, pg_sel;
+
+	/* clear pg_sel field */
+	pab_ctrl_dw = csr_readl(pcie, PAB_CTRL);
+	pab_ctrl_dw = (pab_ctrl_dw & ~(PAGE_SEL_MASK << PAGE_SEL_SHIFT));
+
+	/* set pg_sel field */
+	pg_sel = (offset >> PAGE_SEL_OFFSET_SHIFT) & PAGE_SEL_MASK;
+	pab_ctrl_dw |= ((pg_sel << PAGE_SEL_SHIFT));
+	csr_writel(pcie, pab_ctrl_dw, PAB_CTRL);
+}
+
+static void write_paged_register(struct mobiveil_pcie *pcie,
+		u32 val, u32 offset)
+{
+	u32 off = (offset & PAGE_LO_MASK) | PAGE_SEL_EN;
+
+	select_paged_register(pcie, offset);
+	csr_writel(pcie, val, off);
+}
+
+static u32 read_paged_register(struct mobiveil_pcie *pcie, u32 offset)
+{
+	u32 off = (offset & PAGE_LO_MASK) | PAGE_SEL_EN;
+
+	select_paged_register(pcie, offset);
+	return csr_readl(pcie, off);
+}
+
+static void program_ib_windows(struct mobiveil_pcie *pcie, int win_num,
+		int pci_addr, u32 type,	int size)
+{
+	int pio_ctrl_val;
+	int amap_ctrl_dw;
+	u64 size64 =  ~(size-1);
+
+	if ((pcie->ib_wins_configured + 1) > pcie->ppio_wins) {
+		dev_err(&pcie->pdev->dev,
+			"ERROR: max inbound windows reached !\n");
+		return;
+	}
+
+	pio_ctrl_val = csr_readl(pcie, PAB_PEX_PIO_CTRL);
+	csr_writel(pcie,
+		pio_ctrl_val | (1 << PIO_ENABLE_SHIFT), PAB_PEX_PIO_CTRL);
+	amap_ctrl_dw =	read_paged_register(pcie, PAB_PEX_AMAP_CTRL(win_num));
+	amap_ctrl_dw = (amap_ctrl_dw | (type << AMAP_CTRL_TYPE_SHIFT));
+	amap_ctrl_dw = (amap_ctrl_dw | (1 << AMAP_CTRL_EN_SHIFT));
+
+	write_paged_register(pcie, amap_ctrl_dw | lower_32_bits(size64),
+				PAB_PEX_AMAP_CTRL(win_num));
+
+	write_paged_register(pcie, upper_32_bits(size64),
+				PAB_EXT_PEX_AMAP_SIZEN(win_num));
+
+	write_paged_register(pcie, pci_addr, PAB_PEX_AMAP_AXI_WIN(win_num));
+	write_paged_register(pcie, pci_addr, PAB_PEX_AMAP_PEX_WIN_L(win_num));
+	write_paged_register(pcie, 0, PAB_PEX_AMAP_PEX_WIN_H(win_num));
+}
+
+/*
+ * routine to program the outbound windows
+ */
+static void program_ob_windows(struct mobiveil_pcie *pcie, int win_num,
+		u64 cpu_addr, u64 pci_addr, u32 config_io_bit,
+		int size)
+{
+
+	u32 value, type;
+	u64 size64 =  ~(size-1);
+
+	if ((pcie->ob_wins_configured + 1) > pcie->apio_wins) {
+		dev_err(&pcie->pdev->dev,
+			"ERROR: max outbound windows reached !\n");
+		return;
+	}
+
+	/*
+	 * program Enable Bit to 1, Type Bit to (00) base 2, AXI Window Size Bit
+	 * to 4 KB in PAB_AXI_AMAP_CTRL register
+	 */
+	type = config_io_bit;
+	value = csr_readl(pcie, PAB_AXI_AMAP_CTRL(win_num));
+	csr_writel(pcie,
+			1 << WIN_ENABLE_SHIFT |
+			type << WIN_TYPE_SHIFT |
+			lower_32_bits(size64),
+			PAB_AXI_AMAP_CTRL(win_num));
+
+	write_paged_register(pcie, upper_32_bits(size64),
+				PAB_EXT_AXI_AMAP_SIZE(win_num));
+
+	/*
+	 * program AXI window base with appropriate value in
+	 * PAB_AXI_AMAP_AXI_WIN0 register
+	 */
+	value = csr_readl(pcie, PAB_AXI_AMAP_AXI_WIN(win_num));
+	csr_writel(pcie,
+			cpu_addr >> AXI_WINDOW_BASE_SHIFT <<
+			AXI_WINDOW_BASE_SHIFT, PAB_AXI_AMAP_AXI_WIN(win_num));
+
+	value = csr_readl(pcie, PAB_AXI_AMAP_PEX_WIN_H(win_num));
+
+	csr_writel(pcie, lower_32_bits(pci_addr),
+			PAB_AXI_AMAP_PEX_WIN_L(win_num));
+	csr_writel(pcie, upper_32_bits(pci_addr),
+			PAB_AXI_AMAP_PEX_WIN_H(win_num));
+
+	pcie->ob_wins_configured++;
+}
+
+static int mobiveil_bringup_link(struct mobiveil_pcie *pcie)
+{
+	int retries;
+
+	/* check if the link is up or not */
+	for (retries = 0; retries < LINK_WAIT_MAX_RETRIES; retries++) {
+		if (mobiveil_pcie_link_up(pcie))
+			return 0;
+
+		usleep_range(LINK_WAIT_MIN, LINK_WAIT_MAX);
+	}
+	dev_err(&pcie->pdev->dev, "link never came up\n");
+	return -ETIMEDOUT;
+}
+
+static int mobiveil_host_init(struct mobiveil_pcie *pcie)
+{
+	u32 value;
+	u32 type = 0;
+	u32 pab_ctrl;
+	int err;
+	struct resource_entry *win, *tmp;
+
+	err = mobiveil_bringup_link(pcie);
+	if (err) {
+		dev_info(&pcie->pdev->dev, "link bring-up failed\n");
+		return err;
+	}
+
+	/*
+	 * program Bus Master Enable Bit in Command Register in PAB Config
+	 * Space
+	 */
+	value = csr_readl(pcie, PCI_COMMAND);
+	csr_writel(pcie, value | PCI_COMMAND_IO | PCI_COMMAND_MEMORY |
+		PCI_COMMAND_MASTER,	PCI_COMMAND);
+
+	/*
+	 * program PIO Enable Bit to 1 (and PEX PIO Enable to 1) in PAB_CTRL
+	 * register
+	 */
+	pab_ctrl = csr_readl(pcie, PAB_CTRL);
+	csr_writel(pcie, pab_ctrl | (1 << AMBA_PIO_ENABLE_SHIFT) |
+		(1 << PEX_PIO_ENABLE_SHIFT),
+		PAB_CTRL);
+
+	csr_writel(pcie, (PAB_INTP_INTX_MASK | PAB_INTP_MSI_MASK),
+		PAB_INTP_AMBA_MISC_ENB);
+
+	/* program PIO Enable Bit to 1 and Config Window Enable Bit to 1 in
+	 * PAB_AXI_PIO_CTRL Register
+	 */
+	value = csr_readl(pcie, PAB_AXI_PIO_CTRL);
+	csr_writel(pcie, value | APIO_EN_MASK, PAB_AXI_PIO_CTRL);
+
+	/*
+	 * we'll program one outbound window for config reads and
+	 * another default inbound window for all the upstream traffic
+	 * rest of the outbound windows will be configured according to
+	 * the "ranges" field defined in device tree
+	 */
+
+	/* config outbound translation window */
+	program_ob_windows(pcie, pcie->ob_wins_configured,
+			pcie->ob_io_res->start,	0, CFG_WINDOW_TYPE,
+			resource_size(pcie->ob_io_res));
+
+	/* memory inbound  translation window */
+	program_ib_windows(pcie, WIN_NUM_1, 0, MEM_WINDOW_TYPE, IB_WIN_SIZE);
+
+	/* Get the I/O and memory ranges from DT */
+	resource_list_for_each_entry_safe(win, tmp, &pcie->resources) {
+		type = 0;
+		if (resource_type(win->res) == IORESOURCE_MEM)
+			type = MEM_WINDOW_TYPE;
+		if (resource_type(win->res) == IORESOURCE_IO)
+			type = IO_WINDOW_TYPE;
+		if (type) {
+			/* configure outbound translation window */
+			program_ob_windows(pcie, pcie->ob_wins_configured,
+				win->res->start, 0, type,
+				resource_size(win->res));
+		}
+	}
+
+	return err;
+}
+
+static void mobiveil_mask_intx_irq(struct irq_data *data)
+{
+	struct irq_desc *desc = irq_to_desc(data->irq);
+	struct mobiveil_pcie *pcie;
+	unsigned long flags;
+	u32 mask;
+	u32 shifted_val;
+
+	pcie = irq_desc_get_chip_data(desc);
+	mask = 1 << ((data->hwirq + PAB_INTA_POS) - 1);
+	raw_spin_lock_irqsave(&pcie->intx_mask_lock, flags);
+	shifted_val = csr_readl(pcie, PAB_INTP_AMBA_MISC_ENB);
+	csr_writel(pcie, (shifted_val & (~mask)), PAB_INTP_AMBA_MISC_ENB);
+	raw_spin_unlock_irqrestore(&pcie->intx_mask_lock, flags);
+}
+
+static void mobiveil_unmask_intx_irq(struct irq_data *data)
+{
+	struct irq_desc *desc = irq_to_desc(data->irq);
+	struct mobiveil_pcie *pcie;
+	unsigned long flags;
+	u32 shifted_val;
+	u32 mask;
+
+	pcie = irq_desc_get_chip_data(desc);
+	mask = 1 << ((data->hwirq + PAB_INTA_POS) - 1);
+	raw_spin_lock_irqsave(&pcie->intx_mask_lock, flags);
+	shifted_val = csr_readl(pcie, PAB_INTP_AMBA_MISC_ENB);
+	csr_writel(pcie, (shifted_val | mask), PAB_INTP_AMBA_MISC_ENB);
+	raw_spin_unlock_irqrestore(&pcie->intx_mask_lock, flags);
+}
+
+static struct irq_chip intx_irq_chip = {
+	.name = "mobiveil_pcie:intx",
+	.irq_enable = mobiveil_unmask_intx_irq,
+	.irq_disable = mobiveil_mask_intx_irq,
+	.irq_mask = mobiveil_mask_intx_irq,
+	.irq_unmask = mobiveil_unmask_intx_irq,
+};
+
+/* routine to setup the INTx related data */
+static int mobiveil_pcie_intx_map(struct irq_domain *domain, unsigned int irq,
+		irq_hw_number_t hwirq)
+{
+	irq_set_chip_and_handler(irq, &intx_irq_chip, handle_simple_irq);
+	irq_set_chip_data(irq, domain->host_data);
+	return 0;
+}
+
+/* INTx domain operations structure */
+static const struct irq_domain_ops intx_domain_ops = {
+	.map = mobiveil_pcie_intx_map,
+	.xlate = pci_irqd_intx_xlate,
+};
+
+static int mobiveil_pcie_init_irq_domain(struct mobiveil_pcie *pcie)
+{
+	struct device *dev = &pcie->pdev->dev;
+	struct device_node *node = dev->of_node;
+	int ret;
+
+	/* setup INTx */
+	pcie->intx_domain = irq_domain_add_linear(node,
+				PCI_NUM_INTX + 1, &intx_domain_ops, pcie);
+
+	if (!pcie->intx_domain) {
+		dev_err(dev, "Failed to get a INTx IRQ domain\n");
+		return -ENODEV;
+	}
+
+	raw_spin_lock_init(&pcie->intx_mask_lock);
+
+	return 0;
+}
+
+static int mobiveil_pcie_probe(struct platform_device *pdev)
+{
+	struct mobiveil_pcie *pcie;
+	struct pci_bus *bus;
+	struct pci_bus *child;
+	struct pci_host_bridge *bridge;
+	struct device *dev = &pdev->dev;
+	struct device_node *node = dev->of_node;
+	resource_size_t iobase;
+	int ret;
+
+	/* allocate the PCIe port */
+	bridge = devm_pci_alloc_host_bridge(dev, sizeof(*pcie));
+	if (!bridge)
+		return -ENODEV;
+
+	pcie = pci_host_bridge_priv(bridge);
+	if (!pcie)
+		return -ENOMEM;
+
+	pcie->pdev = pdev;
+
+	ret = mobiveil_pcie_parse_dt(pcie);
+	if (ret) {
+		dev_err(dev, "Parsing DT failed, ret: %x\n", ret);
+		return ret;
+	}
+
+	INIT_LIST_HEAD(&pcie->resources);
+
+	/* parse the host bridge base addresses from the device tree file */
+	ret = of_pci_get_host_bridge_resources(node,
+			0, 0xff, &pcie->resources, &iobase);
+	if (ret) {
+		dev_err(dev, "Getting bridge resources failed\n");
+		return -ENOMEM;
+	}
+
+	/*
+	 * configure all inbound and outbound windows and prepare the RC for
+	 * config access
+	 */
+	ret = mobiveil_host_init(pcie);
+	if (ret) {
+		dev_err(dev, "Failed to initialize host\n");
+		goto error;
+	}
+
+	/* fixup for PCIe class register */
+	csr_writel(pcie, 0x060402ab, PAB_INTP_AXI_PIO_CLASS);
+
+	/* initialize the IRQ domains */
+	ret = mobiveil_pcie_init_irq_domain(pcie);
+	if (ret) {
+		dev_err(dev, "Failed creating IRQ Domain\n");
+		goto error;
+	}
+
+	ret = devm_request_pci_bus_resources(dev, &pcie->resources);
+	if (ret)
+		goto error;
+
+	/* Initialize bridge */
+	list_splice_init(&pcie->resources, &bridge->windows);
+	bridge->dev.parent = dev;
+	bridge->sysdata = pcie;
+	bridge->busnr = pcie->root_bus_nr;
+	bridge->ops = &mobiveil_pcie_ops;
+	bridge->map_irq = of_irq_parse_and_map_pci;
+	bridge->swizzle_irq = pci_common_swizzle;
+
+	/* setup the kernel resources for the newly added PCIe root bus */
+	ret = pci_scan_root_bus_bridge(bridge);
+	if (ret)
+		goto error;
+
+	bus = bridge->bus;
+
+	pci_assign_unassigned_bus_resources(bus);
+	list_for_each_entry(child, &bus->children, node)
+		pcie_bus_configure_settings(child);
+	pci_bus_add_devices(bus);
+
+	platform_set_drvdata(pdev, pcie);
+
+	return 0;
+error:
+	pci_free_resource_list(&pcie->resources);
+	return ret;
+}
+
+static const struct of_device_id mobiveil_pcie_of_match[] = {
+	{.compatible = "mbvl,gpex40-pcie",},
+};
+
+MODULE_DEVICE_TABLE(of, mobiveil_pcie_of_match);
+
+static struct platform_driver mobiveil_pcie_driver = {
+	.probe = mobiveil_pcie_probe,
+	.driver = {
+			.name = "mobiveil-pcie",
+			.of_match_table = mobiveil_pcie_of_match,
+			.suppress_bind_attrs = true,
+		},
+};
+
+builtin_platform_driver(mobiveil_pcie_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Mobiveil PCIe host controller driver");
+MODULE_AUTHOR("Subrahmanya Lingappa <l.subrahmanya@mobiveil.co.in>");