Lorenzo,
On Wed, Dec 20, 2017 at 10:33 PM, Lorenzo Pieralisi
<lorenzo.pieralisi@xxxxxxx> wrote:
>
> On Wed, Dec 13, 2017 at 11:08:37AM -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@xxxxxxxxxxxxxx>
> > Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> > Cc: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
> > Cc: Marc Zyngier <marc.zyngier@xxxxxxx>
> > Cc: linux-pci@xxxxxxxxxxxxxxx
> > Cc: devicetree@xxxxxxxxxxxxxxx
> > ---
> > drivers/pci/host/Kconfig | 8 +
> > drivers/pci/host/Makefile | 1 +
> > drivers/pci/host/pcie-mobiveil.c | 653 +++++++++++++++++++++++++++++++++++++++
> > 3 files changed, 662 insertions(+)
> > create mode 100644 drivers/pci/host/pcie-mobiveil.c
> >
> > diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig
> > index 38d1298..09bf1d9 100644
> > --- a/drivers/pci/host/Kconfig
> > +++ b/drivers/pci/host/Kconfig
> > @@ -27,6 +27,14 @@ config PCIE_XILINX_NWL
> > or End Point. The current option selection will only
> > support root port enabling.
> >
> > +config PCIE_MOBIVEIL
> > + bool "Mobiveil AXI PCIe host bridge support"
> > + depends on ARCH_ZYNQMP || COMPILE_TEST
> > + depends on PCI_MSI_IRQ_DOMAIN
>
> There is no PCI_MSI_IRQ_DOMAIN dependency in this patch.
>
> > + help
> > + Say 'Y' here if you want kernel to support the Mobiveil AXI PCIe
> > + Host Bridge driver.
> > +
> > config PCI_FTPCI100
> > bool "Faraday Technology FTPCI100 PCI controller"
> > depends on OF
> > diff --git a/drivers/pci/host/Makefile b/drivers/pci/host/Makefile
> > index 34ec1d8..d745d68 100644
> > --- a/drivers/pci/host/Makefile
> > +++ b/drivers/pci/host/Makefile
> > @@ -23,6 +23,7 @@ obj-$(CONFIG_PCIE_ROCKCHIP) += pcie-rockchip.o
> > obj-$(CONFIG_PCIE_MEDIATEK) += pcie-mediatek.o
> > obj-$(CONFIG_PCIE_TANGO_SMP8759) += pcie-tango.o
> > obj-$(CONFIG_VMD) += vmd.o
> > +obj-$(CONFIG_PCIE_MOBIVEIL) += pcie-mobiveil.o
> >
> > # The following drivers are for devices that use the generic ACPI
> > # pci_root.c driver but don't support standard ECAM config access.
> > diff --git a/drivers/pci/host/pcie-mobiveil.c b/drivers/pci/host/pcie-mobiveil.c
> > new file mode 100644
> > index 0000000..8611aaa
> > --- /dev/null
> > +++ b/drivers/pci/host/pcie-mobiveil.c
> > @@ -0,0 +1,653 @@
> > +/*
> > + * 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@xxxxxxxxxxxxxx>
> > + */
> > +
> > +#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_4 4
> > +#define PAB_REG_BLOCK_SIZE_16 16
>
> What I wanted to say is that you can tag the block with a name
> instead of using a number.
>
> I can say that block size 4 is only for PAB_EXT_*, you can tag
> it as such.
>
> eg PAB_EXT_REG_BLOCK_SIZE
Ok, I'll rename them as below, and use them accordingly.
#define PAB_REG_BLOCK_SIZE 16
#define PAB_EXT_REG_BLOCK_SIZE 4
>
>
> > +#define PAB_REG_ADDR_4(offset, win) (offset + (win * PAB_REG_BLOCK_SIZE_4))
> > +#define PAB_REG_ADDR_16(offset, win) (offset + (win * PAB_REG_BLOCK_SIZE_16))
> > +
> > +#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_16(0x0ba0, win)
> > +#define WIN_ENABLE_SHIFT 0
> > +#define WIN_TYPE_SHIFT 1
> > +#define WIN_SIZE_SHIFT 10
> > +
> > +#define PAB_EXT_AXI_AMAP_SIZE(win) PAB_REG_ADDR_4(0xbaf0, win)
> > +
> > +#define PAB_AXI_AMAP_AXI_WIN(win) PAB_REG_ADDR_16(0x0ba4, win)
> > +#define AXI_WINDOW_BASE_SHIFT 2
> > +
> > +#define PAB_AXI_AMAP_PEX_WIN_L(win) PAB_REG_ADDR_16(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_16(0x0bac, win)
> > +#define PAB_INTP_AXI_PIO_CLASS 0x474
>
> This one is a bit odd here, move it up in the file.
>
> > +#define PAB_PEX_AMAP_CTRL(win) PAB_REG_ADDR_16(0x4ba0, win)
> > +#define AMAP_CTRL_EN_SHIFT 0
> > +#define AMAP_CTRL_TYPE_SHIFT 1
> > +
> > +#define PAB_EXT_PEX_AMAP_SIZEN(win) PAB_REG_ADDR_4(0xbef0, win)
> > +#define PAB_PEX_AMAP_AXI_WIN(win) PAB_REG_ADDR_16(0x4ba4, win)
> > +#define PAB_PEX_AMAP_PEX_WIN_L(win) PAB_REG_ADDR_16(0x4ba8, win)
> > +#define PAB_PEX_AMAP_PEX_WIN_H(win) PAB_REG_ADDR_16(0x4bac, win)
>
> Here you have three base offsets:
>
> 0xb00
> 0x4000
> 0xb000
>
> you can create a macro for each of them, according to what they
> represent and then add an offset into each.
>
> > +
> > +/* supported number of interrupts */
> > +#define PCI_NUM_INTX 4
>
> It is already defined in linux/pci.h
>
> > +#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)
> > +#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
> > +
> > +#ifndef UINT64_MAX
> > +#define UINT64_MAX (u64)(~((u64)0))
> > +#endif
> > +
> > +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 */
> > + struct irq_domain *intx_domain;
> > + 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);
> > +}
> > +
> > +static bool mobiveil_pcie_link_up(struct mobiveil_pcie *pcie)
> > +{
> > + return (csr_readl(pcie, LTSSM_STATUS) &
> > + LTSSM_STATUS_L0_MASK) == LTSSM_STATUS_L0;
> > +}
>
> https://marc.info/?l=linux-pci&m=151329230814614&w=2
>
> Bjorn would like to remove it.
I do not have a solid explanation for this, as I followed the earlier
driver framework. I'll remove it for now.
>
>
> > +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;
> > + u32 intr_status;
> > + unsigned long shifted_status;
>
> Why not u32 ?
>
for_each_set_bit() api warns about the variable not being unsigned
long. So used the same to take out the warning.
> > + u32 bit, virq;
> > + u32 val, mask;
> > +
> > + 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);
>
> Why can't you reuse val to read the status and create shifted_status
> from it ?
>
> eg
>
> shifted_status = val << PAB_INTA_POS;
> csr_writel(pcie, shifted_status, PAB_INTP_AMBA_MISC_STAT);
>
> Just a hint to make the loop more readable. BTW, I do not think that
> writing shifted_status into that register is OK, see below.
>
> > + do {
> > + for_each_set_bit(bit, &shifted_status, PCI_NUM_INTX) {
> > +
> > + /* clear interrupts */
> > + csr_writel(pcie, shifted_status <<
> PAB_INTA_POS,
> > +
> PAB_INTP_AMBA_MISC_STAT);
>
> Should not you clear just the interrupt you are about to handle ?
PAB_INTP_AMBA_MISC_STAT register has INTA, INTB, INTC, INTD status
bits at positions 5,6,7 and 8,
they are RW1C bits, so writing 1 to this bit clears the status.
So here the status read was written back to it to clear.
>
>
> > + 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);
> > +
> > + }
> > +
> > + shifted_status = csr_readl(pcie,
> > + PAB_INTP_AMBA_MISC_STAT);
> > +
> > + } while ((shifted_status >> PAB_INTA_POS) != 0);
>
> I do not understand this. Can you explain to me how the
> register at:
>
> PAB_INTP_AMBA_MISC_STAT
>
> works ?
>
just repeating what explained before, to ease the readablility.
PAB_INTP_AMBA_MISC_STAT register has INTA, INTB, INTC, INTD status
bits at positions 5,6,7 and 8,
they are RW1C bits, so writing 1 to this bit clears the status.
>
> A patch for mediatek has been posted:
>
> https://patchwork.ozlabs.org/patch/851181/
>
> It looks like this loop may suffer from the same issue, so please do
> have a look.
>
I will clear the the interrupt after
its hadled by generic_handle_irq()
.
right ?
>
> On top of that, most of the operations you are carrying out here
> can be done automatically by making them part of the struct irq_chip
> methods (ie acking IRQs, masking IRQs, etc, see below).
>
Any side effects of keeping this code as is ?
>
> > + }
> > +
> > + 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);
> > +
> > + /* read the number of windows requested */
> > + if (!pcie->apio_wins &&
> > + of_property_read_u32(node, "apio-wins", &pcie->apio_wins)) {
> > + pcie->apio_wins = MAX_PIO_WINDOWS;
> > + }
> > +
> > + if (!pcie->ppio_wins &&
>
> What I wanted to say in my previous review is that apio_wins and
> ppio_wins are zero here why would they be any different and why
> do you need to check that.
Understood. I will remove this redundant check.
>
>
> > + 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, int type, int size_kb)
> > +{
> > + int pio_ctrl_val;
> > + int amap_ctrl_dw;
> > + u64 size64 = (UINT64_MAX << (WIN_SIZE_SHIFT + ilog2(size_kb)));
> > +
> > + 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));
> > +}
> > +
> > +static void program_ob_windows(struct mobiveil_pcie *pcie, int win_num,
> > + u64 cpu_addr, u64 pci_addr, int config_io_bit,
> > + int size_kb)
> > +{
> > +
> > + u32 value, type;
> > + u64
> size64 = (UINT64_MAX << (WIN_SIZE_SHIFT +
> ilog2(size_kb)));
>
> Can you explain to me the sizing mechanism please ? It is just to make
> sure I got it right.
this register follows the PCI BAR sizing convention.
size64 is actually ~(size-1),
Looks like we can just do that instead of jugglery of bit shifting and ilog2().
>
>
> > + 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));
>
> What's "value" used for in this function ?
My bad, it was used in the previous versions and not cleaned up. I will now.
>
>
>
> > + 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;
> > + int type = 0;
>
> You reinitialize it later and it should not be an int but an unsigned
> type.
>
> > + u32 pab_ctrl;
> > + int err;
> > + struct resource_entry *win, *tmp;
> > +
> > + /* setup the PCIe slot link power*/
>
> Comment is useless, remove it.
>
> > + 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 |
>
> Why is this on a separate line ?
>
> > + 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_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)/1024);
> > +
> > + /* 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)/1024);
> > + }
> > + }
> > +
> > + return err;
> > +}
> > +
> > +/* 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, &dummy_irq_chip, handle_simple_irq);
>
> IIUC, the host bridge acts as an INTX/MSI controller/multiplexer.
>
> So, instead of relying on
> dummy_irq_chip, you should create your own
> irq_chip with the methods that you require (eg irq_ack(), irq_mask(),
> irq_compose_msi_msg()) and use that as bottom irq_chip for both
> INTX and MSI domains.
>
> That's why I asked you to have a look at pcie-tango.c (except that there
> INTX aren't supported but the basic idea does not change) and implement
> IRQ domains handling like that same driver.
>
are there any disadvantages of keeping dummy_irq_chip, as I see quite
a few host bridge
drivers including
otehr two major soft IP drivers from altera and xilinx with similar
MSI implementaion.
>
> > + irq_set_chip_data(irq, domain->host_data);
> > + return 0;
> > +}
> > +
> > +/* INTx domain opeartions structure */
>
> s/opeartions/operations
>
> > +static const struct irq_domain_ops intx_domain_ops = {
> > + .map = mobiveil_pcie_intx_map,
> > +};
> > +
> > +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;
>
> ret is unused
>
> > + /* setup INTx */
> > + pcie->intx_domain = irq_domain_add_linear(node,
> > + PCI_NUM_INTX + 1, &intx_domain_ops, pcie);
>
> You should use PCI_NUM_INTX and add pci_irqd_intx_xlate() as the
> domain ops .xlate.
>
> > + if (!pcie->intx_domain) {
> > + dev_err(dev, "Failed to get a INTx IRQ domain\n");
> > + return -ENODEV;
> > + }
> > +
> > + 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;
> > +
> > + /* parse the device tree */
>
> Remove this comment, it does not add anything.
>
> > + 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;
> > + }
> > +
> > +
>
> Two empty lines, should be one.
>
> > + 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);
>
> Is this really needed ?
>
> Thanks,
> Lorenzo
>
> > +
> > + 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@xxxxxxxxxxxxxx>");
> > --
> > 1.8.3.1
> >
Thanks,
Subrahmanya
