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SubjectRe: [PATCH v5 1/4] pci: APM X-Gene PCIe controller driver
On Wed, Mar 19, 2014 at 11:12:39PM +0000, Tanmay Inamdar wrote:
> This patch adds the AppliedMicro X-Gene SOC PCIe controller driver.
> X-Gene PCIe controller supports maximum up to 8 lanes and GEN3 speed.
> X-Gene SOC supports maximum 5 PCIe ports.
>
> Signed-off-by: Tanmay Inamdar <tinamdar@apm.com>

Hi Tanmay,

Some comments below.

> ---
> drivers/pci/host/Kconfig | 10 +
> drivers/pci/host/Makefile | 1 +
> drivers/pci/host/pci-xgene.c | 725 ++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 736 insertions(+)
> create mode 100644 drivers/pci/host/pci-xgene.c
>
> diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig
> index 47d46c6..19ce97d 100644
> --- a/drivers/pci/host/Kconfig
> +++ b/drivers/pci/host/Kconfig
> @@ -33,4 +33,14 @@ config PCI_RCAR_GEN2
> There are 3 internal PCI controllers available with a single
> built-in EHCI/OHCI host controller present on each one.
>
> +config PCI_XGENE
> + bool "X-Gene PCIe controller"
> + depends on ARCH_XGENE
> + depends on OF
> + select PCIEPORTBUS
> + help
> + Say Y here if you want internal PCI support on APM X-Gene SoC.
> + There are 5 internal PCIe ports available. Each port is GEN3 capable
> + and have varied lanes from x1 to x8.
> +
> endmenu
> diff --git a/drivers/pci/host/Makefile b/drivers/pci/host/Makefile
> index 13fb333..34c7c36 100644
> --- a/drivers/pci/host/Makefile
> +++ b/drivers/pci/host/Makefile
> @@ -4,3 +4,4 @@ obj-$(CONFIG_PCI_IMX6) += pci-imx6.o
> obj-$(CONFIG_PCI_MVEBU) += pci-mvebu.o
> obj-$(CONFIG_PCI_TEGRA) += pci-tegra.o
> obj-$(CONFIG_PCI_RCAR_GEN2) += pci-rcar-gen2.o
> +obj-$(CONFIG_PCI_XGENE) += pci-xgene.o
> diff --git a/drivers/pci/host/pci-xgene.c b/drivers/pci/host/pci-xgene.c
> new file mode 100644
> index 0000000..9e312f6
> --- /dev/null
> +++ b/drivers/pci/host/pci-xgene.c
> @@ -0,0 +1,725 @@
> +/**
> + * APM X-Gene PCIe Driver
> + *
> + * Copyright (c) 2013 Applied Micro Circuits Corporation.
> + *
> + * Author: Tanmay Inamdar <tinamdar@apm.com>.
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of the GNU General Public License as published by the
> + * Free Software Foundation; either version 2 of the License, or (at your
> + * option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + */
> +#include <linux/clk-private.h>
> +#include <linux/delay.h>
> +#include <linux/io.h>
> +#include <linux/jiffies.h>
> +#include <linux/memblock.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_address.h>
> +#include <linux/of_irq.h>
> +#include <linux/of_pci.h>
> +#include <linux/pci.h>
> +#include <linux/platform_device.h>
> +#include <linux/slab.h>
> +
> +#define PCIECORE_LTSSM 0x4c
> +#define PCIECORE_CTLANDSTATUS 0x50
> +#define INTXSTATUSMASK 0x6c
> +#define PIM1_1L 0x80
> +#define IBAR2 0x98
> +#define IR2MSK 0x9c
> +#define PIM2_1L 0xa0
> +#define IBAR3L 0xb4
> +#define IR3MSKL 0xbc
> +#define PIM3_1L 0xc4
> +#define OMR1BARL 0x100
> +#define OMR2BARL 0x118
> +#define OMR3BARL 0x130
> +#define CFGBARL 0x154
> +#define CFGBARH 0x158
> +#define CFGCTL 0x15c
> +#define RTDID 0x160
> +#define BRIDGE_CFG_0 0x2000
> +#define BRIDGE_CFG_1 0x2004
> +#define BRIDGE_CFG_4 0x2010
> +#define BRIDGE_CFG_32 0x2030
> +#define BRIDGE_CFG_14 0x2038
> +#define BRIDGE_CTRL_1 0x2204
> +#define BRIDGE_CTRL_2 0x2208
> +#define BRIDGE_CTRL_5 0x2214
> +#define BRIDGE_STATUS_0 0x2600
> +#define MEM_RAM_SHUTDOWN 0xd070
> +#define BLOCK_MEM_RDY 0xd074
> +
> +#define DEVICE_PORT_TYPE_MASK 0x03c00000
> +#define PM_FORCE_RP_MODE_MASK 0x00000400
> +#define SWITCH_PORT_MODE_MASK 0x00000800
> +#define CLASS_CODE_MASK 0xffffff00
> +#define LINK_UP_MASK 0x00000100
> +#define AER_OPTIONAL_ERROR_EN 0xffc00000
> +#define XGENE_PCIE_DEV_CTRL 0x2f0f
> +#define AXI_EP_CFG_ACCESS 0x10000
> +#define ENABLE_ASPM 0x08000000
> +#define XGENE_PORT_TYPE_RC 0x05000000
> +#define BLOCK_MEM_RDY_VAL 0xFFFFFFFF
> +#define EN_COHERENCY 0xF0000000
> +#define EN_REG 0x00000001
> +#define OB_LO_IO 0x00000002
> +#define XGENE_PCIE_VENDORID 0xE008
> +#define XGENE_PCIE_DEVICEID 0xE004
> +#define XGENE_PCIE_ECC_TIMEOUT 10 /* ms */
> +#define XGENE_LTSSM_DETECT_WAIT 20 /* ms */
> +#define XGENE_LTSSM_L0_WAIT 4 /* ms */
> +#define SZ_1T (SZ_1G*1024ULL)
> +#define PIPE_PHY_RATE_RD(src) ((0xc000 & (u32)(src)) >> 0xe)
> +
> +struct xgene_pcie_port {
> + struct device_node *node;
> + struct device *dev;
> + struct clk *clk;
> + void __iomem *csr_base;
> + void __iomem *cfg_base;
> + u8 link_up;
> +};
> +
> +static inline u32 pcie_bar_low_val(u32 addr, u32 flags)
> +{
> + return (addr & PCI_BASE_ADDRESS_MEM_MASK) | flags;
> +}
> +
> +/* PCIE Configuration Out/In */
> +static inline void xgene_pcie_cfg_out32(void __iomem *addr, int offset, u32 val)
> +{
> + writel(val, addr + offset);
> +}
> +
> +static inline void xgene_pcie_cfg_out16(void __iomem *addr, int offset, u16 val)
> +{
> + u32 val32 = readl(addr + (offset & ~0x3));
> +
> + switch (offset & 0x3) {
> + case 2:
> + val32 &= ~0xFFFF0000;
> + val32 |= (u32)val << 16;
> + break;
> + case 0:
> + default:
> + val32 &= ~0xFFFF;
> + val32 |= val;
> + break;
> + }
> + writel(val32, addr + (offset & ~0x3));
> +}
> +
> +static inline void xgene_pcie_cfg_out8(void __iomem *addr, int offset, u8 val)
> +{
> + u32 val32 = readl(addr + (offset & ~0x3));
> +
> + switch (offset & 0x3) {
> + case 0:
> + val32 &= ~0xFF;
> + val32 |= val;
> + break;
> + case 1:
> + val32 &= ~0xFF00;
> + val32 |= (u32)val << 8;
> + break;
> + case 2:
> + val32 &= ~0xFF0000;
> + val32 |= (u32)val << 16;
> + break;
> + case 3:
> + default:
> + val32 &= ~0xFF000000;
> + val32 |= (u32)val << 24;
> + break;
> + }
> + writel(val32, addr + (offset & ~0x3));
> +}
> +
> +static inline void xgene_pcie_cfg_in32(void __iomem *addr, int offset, u32 *val)
> +{
> + *val = readl(addr + offset);
> +}
> +
> +static inline void
> +xgene_pcie_cfg_in16(void __iomem *addr, int offset, u32 *val)
> +{
> + *val = readl(addr + (offset & ~0x3));
> +
> + switch (offset & 0x3) {
> + case 2:
> + *val >>= 16;
> + break;
> + }
> +
> + *val &= 0xFFFF;
> +}
> +
> +static inline void
> +xgene_pcie_cfg_in8(void __iomem *addr, int offset, u32 *val)
> +{
> + *val = readl(addr + (offset & ~0x3));
> +
> + switch (offset & 0x3) {
> + case 3:
> + *val = *val >> 24;
> + break;
> + case 2:
> + *val = *val >> 16;
> + break;
> + case 1:
> + *val = *val >> 8;
> + break;
> + }
> + *val &= 0xFF;
> +}
> +
> +/* When the address bit [17:16] is 2'b01, the Configuration access will be
> + * treated as Type 1 and it will be forwarded to external PCIe device.
> + */
> +static void __iomem *xgene_pcie_get_cfg_base(struct pci_bus *bus)
> +{
> + struct xgene_pcie_port *port = bus->sysdata;
> +
> + if (bus->number >= (bus->primary + 1))
I fail to see the link between what the comment says and what the code does. It
looks to me like any bus with a number from bus->primary +1 onwards will have
it's cfg_base altered. How does that translate into address bits?

> + return port->cfg_base + AXI_EP_CFG_ACCESS;
> +
> + return port->cfg_base;
> +}
> +
> +/* For Configuration request, RTDID register is used as Bus Number,
> + * Device Number and Function number of the header fields.
> + */
> +static void xgene_pcie_set_rtdid_reg(struct pci_bus *bus, uint devfn)
> +{
> + struct xgene_pcie_port *port = bus->sysdata;
> + unsigned int b, d, f;
> + u32 rtdid_val = 0;
> +
> + b = bus->number;
> + d = PCI_SLOT(devfn);
> + f = PCI_FUNC(devfn);
> +
> + if (!pci_is_root_bus(bus))
> + rtdid_val = (b << 8) | (d << 3) | f;
> +
> + writel(rtdid_val, port->csr_base + RTDID);
> + /* read the register back to ensure flush */
> + readl(port->csr_base + RTDID);
> +}
> +
> +static int xgene_pcie_read_config(struct pci_bus *bus, unsigned int devfn,
> + int offset, int len, u32 *val)
> +{
> + struct xgene_pcie_port *port = bus->sysdata;
> + void __iomem *addr;
> +
> + if ((pci_is_root_bus(bus) && devfn != 0) || !port->link_up)
> + return PCIBIOS_DEVICE_NOT_FOUND;
> +
> + xgene_pcie_set_rtdid_reg(bus, devfn);
> + addr = xgene_pcie_get_cfg_base(bus);
> + switch (len) {
> + case 1:
> + xgene_pcie_cfg_in8(addr, offset, val);
> + break;
> + case 2:
> + xgene_pcie_cfg_in16(addr, offset, val);
> + break;
> + default:
> + xgene_pcie_cfg_in32(addr, offset, val);
> + break;
> + }
> + return PCIBIOS_SUCCESSFUL;
> +}
> +
> +static int xgene_pcie_write_config(struct pci_bus *bus, unsigned int devfn,
> + int offset, int len, u32 val)
> +{
> + struct xgene_pcie_port *port = bus->sysdata;
> + void __iomem *addr;
> +
> + if ((pci_is_root_bus(bus) && devfn != 0) || !port->link_up)
> + return PCIBIOS_DEVICE_NOT_FOUND;
> +
> + xgene_pcie_set_rtdid_reg(bus, devfn);
> + addr = xgene_pcie_get_cfg_base(bus);
> + switch (len) {
> + case 1:
> + xgene_pcie_cfg_out8(addr, offset, (u8)val);
> + break;
> + case 2:
> + xgene_pcie_cfg_out16(addr, offset, (u16)val);
> + break;
> + default:
> + xgene_pcie_cfg_out32(addr, offset, val);
> + break;
> + }
> + return PCIBIOS_SUCCESSFUL;
> +}
> +
> +static struct pci_ops xgene_pcie_ops = {
> + .read = xgene_pcie_read_config,
> + .write = xgene_pcie_write_config
> +};
> +
> +static void xgene_pcie_program_core(void __iomem *csr_base)
> +{
> + u32 val;
> +
> + val = readl(csr_base + BRIDGE_CFG_0);
> + val |= AER_OPTIONAL_ERROR_EN;
> + writel(val, csr_base + BRIDGE_CFG_0);
> + writel(0x0, csr_base + INTXSTATUSMASK);
> + val = readl(csr_base + BRIDGE_CTRL_1);
> + val = (val & ~0xffff) | XGENE_PCIE_DEV_CTRL;
> + writel(val, csr_base + BRIDGE_CTRL_1);
> +}
> +
> +static u64 xgene_pcie_set_ib_mask(void __iomem *csr_base, u32 addr,
> + u32 flags, u64 size)
> +{
> + u64 mask = (~(size - 1) & PCI_BASE_ADDRESS_MEM_MASK) | flags;
> + u32 val32 = 0;
> + u32 val;
> +
> + val32 = readl(csr_base + addr);
> + val = (val32 & 0x0000ffff) | (lower_32_bits(mask) << 16);
> + writel(val, csr_base + addr);
> +
> + val32 = readl(csr_base + addr + 0x04);
> + val = (val32 & 0xffff0000) | (lower_32_bits(mask) >> 16);
> + writel(val, csr_base + addr + 0x04);
> +
> + val32 = readl(csr_base + addr + 0x04);
> + val = (val32 & 0x0000ffff) | (upper_32_bits(mask) << 16);
> + writel(val, csr_base + addr + 0x04);
> +
> + val32 = readl(csr_base + addr + 0x08);
> + val = (val32 & 0xffff0000) | (upper_32_bits(mask) >> 16);
> + writel(val, csr_base + addr + 0x08);
> +
> + return mask;
> +}
> +
> +static void xgene_pcie_poll_linkup(struct xgene_pcie_port *port,
> + u32 *lanes, u32 *speed)
> +{
> + void __iomem *csr_base = port->csr_base;
> + ulong timeout;
> + u32 val32;
> +
> + /*
> + * A component enters the LTSSM Detect state within
> + * 20ms of the end of fundamental core reset.
> + */
> + msleep(XGENE_LTSSM_DETECT_WAIT);
> + port->link_up = 0;
> + timeout = jiffies + msecs_to_jiffies(XGENE_LTSSM_L0_WAIT);
> + while (time_before(jiffies, timeout)) {
> + val32 = readl(csr_base + PCIECORE_CTLANDSTATUS);
> + if (val32 & LINK_UP_MASK) {
> + port->link_up = 1;
> + *speed = PIPE_PHY_RATE_RD(val32);
> + val32 = readl(csr_base + BRIDGE_STATUS_0);
> + *lanes = val32 >> 26;
> + break;
> + }
> + msleep(1);
> + }
> +}
> +
> +static void xgene_pcie_setup_root_complex(struct xgene_pcie_port *port)
> +{
> + void __iomem *csr_base = port->csr_base;
> + u32 val;
> +
> + val = (XGENE_PCIE_DEVICEID << 16) | XGENE_PCIE_VENDORID;
> + writel(val, csr_base + BRIDGE_CFG_0);
> +
> + val = readl(csr_base + BRIDGE_CFG_1);
> + val &= ~CLASS_CODE_MASK;
> + val |= PCI_CLASS_BRIDGE_PCI << 16;
> + writel(val, csr_base + BRIDGE_CFG_1);
> +
> + val = readl(csr_base + BRIDGE_CFG_14);
> + val |= SWITCH_PORT_MODE_MASK;
> + val &= ~PM_FORCE_RP_MODE_MASK;
> + writel(val, csr_base + BRIDGE_CFG_14);
> +
> + val = readl(csr_base + BRIDGE_CTRL_5);
> + val &= ~DEVICE_PORT_TYPE_MASK;
> + val |= XGENE_PORT_TYPE_RC;
> + writel(val, csr_base + BRIDGE_CTRL_5);
> +
> + val = readl(csr_base + BRIDGE_CTRL_2);
> + val |= ENABLE_ASPM;
> + writel(val, csr_base + BRIDGE_CTRL_2);
> +
> + val = readl(csr_base + BRIDGE_CFG_32);
> + writel(val | (1 << 19), csr_base + BRIDGE_CFG_32);
> +}
> +
> +/* Return 0 on success */

Comment is not very helpful, this is supposed to be the default behaviour
in kernel code.

> +static int xgene_pcie_init_ecc(struct xgene_pcie_port *port)
> +{
> + void __iomem *csr_base = port->csr_base;
> + ulong timeout;
> + u32 val;
> +
> + val = readl(csr_base + MEM_RAM_SHUTDOWN);
> + if (!val)
> + return 0;
> + writel(0x0, csr_base + MEM_RAM_SHUTDOWN);
> + timeout = jiffies + msecs_to_jiffies(XGENE_PCIE_ECC_TIMEOUT);
> + while (time_before(jiffies, timeout)) {
> + val = readl(csr_base + BLOCK_MEM_RDY);
> + if (val == BLOCK_MEM_RDY_VAL)
> + return 0;
> + msleep(1);
> + }
> +

Maybe add a comment here suggesting this is the error return. Better yet,
use the kernel convention of returning negative numbers for errors and
use one of the errno-base.h values.

> + return 1;
> +}
> +
> +static int xgene_pcie_init_port(struct xgene_pcie_port *port)
> +{
> + int rc;
> +
> + port->clk = clk_get(port->dev, NULL);
> + if (IS_ERR(port->clk)) {
> + dev_err(port->dev, "clock not available\n");
> + return -ENODEV;
> + }
> +
> + rc = clk_prepare_enable(port->clk);
> + if (rc) {
> + dev_err(port->dev, "clock enable failed\n");
> + return rc;
> + }
> +
> + rc = xgene_pcie_init_ecc(port);
> + if (rc) {
> + dev_err(port->dev, "memory init failed\n");
> + return rc;
> + }
> +
> + return 0;
> +}
> +
> +static void xgene_pcie_fixup_bridge(struct pci_dev *dev)
> +{
> + int i;
> +
> + /* Hide the PCI host BARs from the kernel as their content doesn't
> + * fit well in the resource management
> + */
> + for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
> + dev->resource[i].start = dev->resource[i].end = 0;
> + dev->resource[i].flags = 0;
> + }
> + dev_info(&dev->dev, "Hiding X-Gene pci host bridge resources %s\n",
> + pci_name(dev));
> +}
> +DECLARE_PCI_FIXUP_HEADER(XGENE_PCIE_VENDORID, XGENE_PCIE_DEVICEID,
> + xgene_pcie_fixup_bridge);
> +
> +static int xgene_pcie_map_reg(struct xgene_pcie_port *port,
> + struct platform_device *pdev, u64 *cfg_addr)
> +{
> + struct resource *res;
> +
> + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "csr");
> + port->csr_base = devm_ioremap_resource(port->dev, res);
> + if (IS_ERR(port->csr_base))
> + return PTR_ERR(port->csr_base);
> +
> + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "cfg");
> + port->cfg_base = devm_ioremap_resource(port->dev, res);
> + if (IS_ERR(port->cfg_base))
> + return PTR_ERR(port->cfg_base);
> + *cfg_addr = res->start;
> +
> + return 0;
> +}
> +
> +static void xgene_pcie_setup_ob_reg(struct xgene_pcie_port *port,
> + struct resource *res, u32 offset, u64 addr)
> +{
> + void __iomem *base = port->csr_base + offset;
> + resource_size_t size = resource_size(res);
> + u64 restype = resource_type(res);
> + u64 cpu_addr, pci_addr;
> + u64 mask = 0;
> + u32 min_size;
> + u32 flag = EN_REG;
> +
> + if (restype == IORESOURCE_MEM) {
> + cpu_addr = res->start;
> + pci_addr = addr;
> + min_size = SZ_128M;
> + } else {
> + cpu_addr = addr;
> + pci_addr = res->start;
> + min_size = 128;
> + flag |= OB_LO_IO;
> + }
> + if (size >= min_size)
> + mask = ~(size - 1) | flag;
> + else
> + dev_warn(port->dev, "res size 0x%llx less than minimum 0x%x\n",
> + (u64)size, min_size);
> + writel(lower_32_bits(cpu_addr), base);
> + writel(upper_32_bits(cpu_addr), base + 0x04);
> + writel(lower_32_bits(mask), base + 0x08);
> + writel(upper_32_bits(mask), base + 0x0c);
> + writel(lower_32_bits(pci_addr), base + 0x10);
> + writel(upper_32_bits(pci_addr), base + 0x14);
> +}
> +
> +static void xgene_pcie_setup_cfg_reg(void __iomem *csr_base, u64 addr)
> +{
> + writel(lower_32_bits(addr), csr_base + CFGBARL);
> + writel(upper_32_bits(addr), csr_base + CFGBARH);
> + writel(EN_REG, csr_base + CFGCTL);
> +}
> +
> +static int xgene_pcie_map_ranges(struct xgene_pcie_port *port,
> + struct pci_host_bridge *bridge,
> + u64 cfg_addr)
> +{
> + struct device *dev = port->dev;
> + struct pci_host_bridge_window *window;
> + int ret;
> +
> + list_for_each_entry(window, &bridge->windows, list) {
> + struct resource *res = window->res;
> + u64 restype = resource_type(res);
> + dev_dbg(port->dev, "0x%08lx 0x%016llx...0x%016llx\n",
> + res->flags, res->start, res->end);
> +
> + switch (restype) {
> + case IORESOURCE_IO:
> + xgene_pcie_setup_ob_reg(port, res, OMR2BARL,
> + bridge->io_base);
> + ret = pci_ioremap_io(res, bridge->io_base);
> + if (ret < 0)
> + return ret;
> + break;
> + case IORESOURCE_MEM:
> + xgene_pcie_setup_ob_reg(port, res, OMR3BARL,
> + res->start - window->offset);
> + break;
> + case IORESOURCE_BUS:
> + break;
> + default:
> + dev_err(dev, "invalid io resource!");
> + return -EINVAL;
> + }
> + }
> + xgene_pcie_setup_cfg_reg(port->csr_base, cfg_addr);
> + return 0;
> +}
> +
> +static void xgene_pcie_setup_pims(void *addr, u64 pim, u64 size)
> +{
> + writel(lower_32_bits(pim), addr);
> + writel(upper_32_bits(pim) | EN_COHERENCY, addr + 0x04);
> + writel(lower_32_bits(size), addr + 0x10);
> + writel(upper_32_bits(size), addr + 0x14);
> +}
> +
> +/*
> + * X-Gene PCIe support maximum 3 inbound memory regions
> + * This function helps to select a region based on size of region
> + */
> +static int xgene_pcie_select_ib_reg(u8 *ib_reg_mask, u64 size)
> +{
> + if ((size > 4) && (size < SZ_16M) && !(*ib_reg_mask & (1 << 1))) {
> + *ib_reg_mask |= (1 << 1);
> + return 1;
> + }
> +
> + if ((size > SZ_1K) && (size < SZ_1T) && !(*ib_reg_mask & (1 << 0))) {
> + *ib_reg_mask |= (1 << 0);
> + return 0;
> + }
> +
> + if ((size > SZ_1M) && (size < SZ_1T) && !(*ib_reg_mask & (1 << 2))) {
> + *ib_reg_mask |= (1 << 2);
> + return 2;
> + }
> + return -EINVAL;
> +}
> +
> +static void xgene_pcie_setup_ib_reg(struct xgene_pcie_port *port,
> + struct of_pci_range *range, u8 *ib_reg_mask)
> +{
> + void __iomem *csr_base = port->csr_base;
> + void __iomem *cfg_base = port->cfg_base;
> + void *bar_addr;
> + void *pim_addr;
> + u64 restype = range->flags & IORESOURCE_TYPE_BITS;
> + u64 cpu_addr = range->cpu_addr;
> + u64 pci_addr = range->pci_addr;
> + u64 size = range->size;
> + u64 mask = ~(size - 1) | EN_REG;
> + u32 flags = PCI_BASE_ADDRESS_MEM_TYPE_64;
> + u32 bar_low;
> + int region;
> +
> + region = xgene_pcie_select_ib_reg(ib_reg_mask, range->size);
> + if (region < 0) {
> + dev_warn(port->dev, "invalid pcie dma-range config\n");
> + return;
> + }
> +
> + if (restype == PCI_BASE_ADDRESS_MEM_PREFETCH)
> + flags |= PCI_BASE_ADDRESS_MEM_PREFETCH;
> +
> + bar_low = pcie_bar_low_val((u32)cpu_addr, flags);
> + switch (region) {
> + case 0:
> + xgene_pcie_set_ib_mask(csr_base, BRIDGE_CFG_4, flags, size);
> + bar_addr = cfg_base + PCI_BASE_ADDRESS_0;
> + writel(bar_low, bar_addr);
> + writel(upper_32_bits(cpu_addr), bar_addr + 0x4);
> + pim_addr = csr_base + PIM1_1L;
> + break;
> + case 1:
> + bar_addr = csr_base + IBAR2;
> + writel(bar_low, bar_addr);
> + writel(lower_32_bits(mask), csr_base + IR2MSK);
> + pim_addr = csr_base + PIM2_1L;
> + break;
> + case 2:
> + bar_addr = csr_base + IBAR3L;
> + writel(bar_low, bar_addr);
> + writel(upper_32_bits(cpu_addr), bar_addr + 0x4);
> + writel(lower_32_bits(mask), csr_base + IR3MSKL);
> + writel(upper_32_bits(mask), csr_base + IR3MSKL + 0x4);
> + pim_addr = csr_base + PIM3_1L;
> + break;
> + }
> +
> + xgene_pcie_setup_pims(pim_addr, pci_addr, size);
> +}
> +
> +static int pci_dma_range_parser_init(struct of_pci_range_parser *parser,
> + struct device_node *node)
> +{
> + const int na = 3, ns = 2;
> + int rlen;
> +
> + parser->node = node;
> + parser->pna = of_n_addr_cells(node);
> + parser->np = parser->pna + na + ns;
> +
> + parser->range = of_get_property(node, "dma-ranges", &rlen);
> + if (!parser->range)
> + return -ENOENT;
> +
> + parser->end = parser->range + rlen / sizeof(__be32);
> + return 0;
> +}
> +
> +static int xgene_pcie_parse_map_dma_ranges(struct xgene_pcie_port *port)
> +{
> + struct device_node *np = port->node;
> + struct of_pci_range range;
> + struct of_pci_range_parser parser;
> + struct device *dev = port->dev;
> + u8 ib_reg_mask = 0;
> +
> + if (pci_dma_range_parser_init(&parser, np)) {
> + dev_err(dev, "missing dma-ranges property\n");
> + return -EINVAL;
> + }
> +
> + /* Get the dma-ranges from DT */
> + for_each_of_pci_range(&parser, &range) {
> + u64 end = range.cpu_addr + range.size - 1;
> + dev_dbg(port->dev, "0x%08x 0x%016llx..0x%016llx -> 0x%016llx\n",
> + range.flags, range.cpu_addr, end, range.pci_addr);
> + xgene_pcie_setup_ib_reg(port, &range, &ib_reg_mask);
> + }
> + return 0;
> +}
> +
> +static int xgene_pcie_probe_bridge(struct platform_device *pdev)
> +{
> + struct device_node *np = of_node_get(pdev->dev.of_node);
> + struct xgene_pcie_port *port;
> + struct pci_host_bridge *bridge;
> + resource_size_t lastbus;
> + u32 lanes = 0, speed = 0;
> + u64 cfg_addr = 0;
> + int ret;
> +
> + port = devm_kzalloc(&pdev->dev, sizeof(*port), GFP_KERNEL);
> + if (!port)
> + return -ENOMEM;
> + port->node = np;
> + port->dev = &pdev->dev;
> +
> + ret = xgene_pcie_map_reg(port, pdev, &cfg_addr);
> + if (ret)
> + return ret;
> +
> + ret = xgene_pcie_init_port(port);
> + if (ret)
> + return ret;
> + xgene_pcie_program_core(port->csr_base);
> + xgene_pcie_setup_root_complex(port);
> +
> + bridge = of_create_pci_host_bridge(&pdev->dev, &xgene_pcie_ops, port);
> + if (IS_ERR_OR_NULL(bridge))

If bridge is NULL (can't see how in my code, but anyway)

> + return PTR_ERR(bridge);

Then this will return zero (i.e. success).

s/IS_ERR_OR_NULL/IS_ERR/g

> +
> + ret = xgene_pcie_map_ranges(port, bridge, cfg_addr);
> + if (ret)
> + return ret;
> +
> + ret = xgene_pcie_parse_map_dma_ranges(port);
> + if (ret)
> + return ret;
> +
> + xgene_pcie_poll_linkup(port, &lanes, &speed);
> + if (!port->link_up)
> + dev_info(port->dev, "(rc) link down\n");
> + else
> + dev_info(port->dev, "(rc) x%d gen-%d link up\n",
> + lanes, speed + 1);
> + platform_set_drvdata(pdev, port);
> + lastbus = pci_rescan_bus(bridge->bus);

If you look in drivers/pci/probe.c *after* the definition of pci_rescan_bus()
there is a comment about the function needing to be guarded by
pci_lock_rescan_remove() and pci_unlock_rescan_remove(). The only one doing
it is drivers/pci/pci-sysfs.c, while s390 seems oblivious to it.

> + pci_bus_update_busn_res_end(bridge->bus, lastbus);
> + return 0;
> +}
> +
> +static const struct of_device_id xgene_pcie_match_table[] = {
> + {.compatible = "apm,xgene-pcie",},
> + {},
> +};
> +
> +static struct platform_driver xgene_pcie_driver = {
> + .driver = {
> + .name = "xgene-pcie",
> + .owner = THIS_MODULE,
> + .of_match_table = of_match_ptr(xgene_pcie_match_table),
> + },
> + .probe = xgene_pcie_probe_bridge,
> +};
> +module_platform_driver(xgene_pcie_driver);
> +
> +MODULE_AUTHOR("Tanmay Inamdar <tinamdar@apm.com>");
> +MODULE_DESCRIPTION("APM X-Gene PCIe driver");
> +MODULE_LICENSE("GPL v2");
> --
> 1.7.9.5
>
>

--
====================
| I would like to |
| fix the world, |
| but they're not |
| giving me the |
\ source code! /
---------------
¯\_(ツ)_/¯
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