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// SPDX-License-Identifier: GPL-2.0+
/**
* APM X-Gene PCIe Driver
*
* Copyright (c) 2014 Applied Micro Circuits Corporation.
*
* Author: Tanmay Inamdar <tinamdar@apm.com>.
*/
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/jiffies.h>
#include <linux/memblock.h>
#include <linux/init.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/pci-acpi.h>
#include <linux/pci-ecam.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#define PCIECORE_CTLANDSTATUS 0x50
#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_4 0x2010
#define BRIDGE_STATUS_0 0x2600
#define LINK_UP_MASK 0x00000100
#define AXI_EP_CFG_ACCESS 0x10000
#define EN_COHERENCY 0xF0000000
#define EN_REG 0x00000001
#define OB_LO_IO 0x00000002
#define XGENE_PCIE_VENDORID 0x10E8
#define XGENE_PCIE_DEVICEID 0xE004
#define SZ_1T (SZ_1G*1024ULL)
#define PIPE_PHY_RATE_RD(src) ((0xc000 & (u32)(src)) >> 0xe)
#define XGENE_V1_PCI_EXP_CAP 0x40
/* PCIe IP version */
#define XGENE_PCIE_IP_VER_UNKN 0
#define XGENE_PCIE_IP_VER_1 1
#define XGENE_PCIE_IP_VER_2 2
#if defined(CONFIG_PCI_XGENE) || (defined(CONFIG_ACPI) && defined(CONFIG_PCI_QUIRKS))
struct xgene_pcie_port {
struct device_node *node;
struct device *dev;
struct clk *clk;
void __iomem *csr_base;
void __iomem *cfg_base;
unsigned long cfg_addr;
bool link_up;
u32 version;
};
static u32 xgene_pcie_readl(struct xgene_pcie_port *port, u32 reg)
{
return readl(port->csr_base + reg);
}
static void xgene_pcie_writel(struct xgene_pcie_port *port, u32 reg, u32 val)
{
writel(val, port->csr_base + reg);
}
static inline u32 pcie_bar_low_val(u32 addr, u32 flags)
{
return (addr & PCI_BASE_ADDRESS_MEM_MASK) | flags;
}
static inline struct xgene_pcie_port *pcie_bus_to_port(struct pci_bus *bus)
{
struct pci_config_window *cfg;
if (acpi_disabled)
return (struct xgene_pcie_port *)(bus->sysdata);
cfg = bus->sysdata;
return (struct xgene_pcie_port *)(cfg->priv);
}
/*
* 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 = pcie_bus_to_port(bus);
if (bus->number >= (bus->primary + 1))
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 = pcie_bus_to_port(bus);
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;
xgene_pcie_writel(port, RTDID, rtdid_val);
/* read the register back to ensure flush */
xgene_pcie_readl(port, RTDID);
}
/*
* X-Gene PCIe port uses BAR0-BAR1 of RC's configuration space as
* the translation from PCI bus to native BUS. Entire DDR region
* is mapped into PCIe space using these registers, so it can be
* reached by DMA from EP devices. The BAR0/1 of bridge should be
* hidden during enumeration to avoid the sizing and resource allocation
* by PCIe core.
*/
static bool xgene_pcie_hide_rc_bars(struct pci_bus *bus, int offset)
{
if (pci_is_root_bus(bus) && ((offset == PCI_BASE_ADDRESS_0) ||
(offset == PCI_BASE_ADDRESS_1)))
return true;
return false;
}
static void __iomem *xgene_pcie_map_bus(struct pci_bus *bus, unsigned int devfn,
int offset)
{
if ((pci_is_root_bus(bus) && devfn != 0) ||
xgene_pcie_hide_rc_bars(bus, offset))
return NULL;
xgene_pcie_set_rtdid_reg(bus, devfn);
return xgene_pcie_get_cfg_base(bus) + offset;
}
static int xgene_pcie_config_read32(struct pci_bus *bus, unsigned int devfn,
int where, int size, u32 *val)
{
struct xgene_pcie_port *port = pcie_bus_to_port(bus);
if (pci_generic_config_read32(bus, devfn, where & ~0x3, 4, val) !=
PCIBIOS_SUCCESSFUL)
return PCIBIOS_DEVICE_NOT_FOUND;
/*
* The v1 controller has a bug in its Configuration Request
* Retry Status (CRS) logic: when CRS is enabled and we read the
* Vendor and Device ID of a non-existent device, the controller
* fabricates return data of 0xFFFF0001 ("device exists but is not
* ready") instead of 0xFFFFFFFF ("device does not exist"). This
* causes the PCI core to retry the read until it times out.
* Avoid this by not claiming to support CRS.
*/
if (pci_is_root_bus(bus) && (port->version == XGENE_PCIE_IP_VER_1) &&
((where & ~0x3) == XGENE_V1_PCI_EXP_CAP + PCI_EXP_RTCTL))
*val &= ~(PCI_EXP_RTCAP_CRSVIS << 16);
if (size <= 2)
*val = (*val >> (8 * (where & 3))) & ((1 << (size * 8)) - 1);
return PCIBIOS_SUCCESSFUL;
}
#endif
#if defined(CONFIG_ACPI) && defined(CONFIG_PCI_QUIRKS)
static int xgene_get_csr_resource(struct acpi_device *adev,
struct resource *res)
{
struct device *dev = &adev->dev;
struct resource_entry *entry;
struct list_head list;
unsigned long flags;
int ret;
INIT_LIST_HEAD(&list);
flags = IORESOURCE_MEM;
ret = acpi_dev_get_resources(adev, &list,
acpi_dev_filter_resource_type_cb,
(void *) flags);
if (ret < 0) {
dev_err(dev, "failed to parse _CRS method, error code %d\n",
ret);
return ret;
}
if (ret == 0) {
dev_err(dev, "no IO and memory resources present in _CRS\n");
return -EINVAL;
}
entry = list_first_entry(&list, struct resource_entry, node);
*res = *entry->res;
acpi_dev_free_resource_list(&list);
return 0;
}
static int xgene_pcie_ecam_init(struct pci_config_window *cfg, u32 ipversion)
{
struct device *dev = cfg->parent;
struct acpi_device *adev = to_acpi_device(dev);
struct xgene_pcie_port *port;
struct resource csr;
int ret;
port = devm_kzalloc(dev, sizeof(*port), GFP_KERNEL);
if (!port)
return -ENOMEM;
ret = xgene_get_csr_resource(adev, &csr);
if (ret) {
dev_err(dev, "can't get CSR resource\n");
return ret;
}
port->csr_base = devm_pci_remap_cfg_resource(dev, &csr);
if (IS_ERR(port->csr_base))
return PTR_ERR(port->csr_base);
port->cfg_base = cfg->win;
port->version = ipversion;
cfg->priv = port;
return 0;
}
static int xgene_v1_pcie_ecam_init(struct pci_config_window *cfg)
{
return xgene_pcie_ecam_init(cfg, XGENE_PCIE_IP_VER_1);
}
struct pci_ecam_ops xgene_v1_pcie_ecam_ops = {
.bus_shift = 16,
.init = xgene_v1_pcie_ecam_init,
.pci_ops = {
.map_bus = xgene_pcie_map_bus,
.read = xgene_pcie_config_read32,
.write = pci_generic_config_write,
}
};
static int xgene_v2_pcie_ecam_init(struct pci_config_window *cfg)
{
return xgene_pcie_ecam_init(cfg, XGENE_PCIE_IP_VER_2);
}
struct pci_ecam_ops xgene_v2_pcie_ecam_ops = {
.bus_shift = 16,
.init = xgene_v2_pcie_ecam_init,
.pci_ops = {
.map_bus = xgene_pcie_map_bus,
.read = xgene_pcie_config_read32,
.write = pci_generic_config_write,
}
};
#endif
#if defined(CONFIG_PCI_XGENE)
static u64 xgene_pcie_set_ib_mask(struct xgene_pcie_port *port, u32 addr,
u32 flags, u64 size)
{
u64 mask = (~(size - 1) & PCI_BASE_ADDRESS_MEM_MASK) | flags;
u32 val32 = 0;
u32 val;
val32 = xgene_pcie_readl(port, addr);
val = (val32 & 0x0000ffff) | (lower_32_bits(mask) << 16);
xgene_pcie_writel(port, addr, val);
val32 = xgene_pcie_readl(port, addr + 0x04);
val = (val32 & 0xffff0000) | (lower_32_bits(mask) >> 16);
xgene_pcie_writel(port, addr + 0x04, val);
val32 = xgene_pcie_readl(port, addr + 0x04);
val = (val32 & 0x0000ffff) | (upper_32_bits(mask) << 16);
xgene_pcie_writel(port, addr + 0x04, val);
val32 = xgene_pcie_readl(port, addr + 0x08);
val = (val32 & 0xffff0000) | (upper_32_bits(mask) >> 16);
xgene_pcie_writel(port, addr + 0x08, val);
return mask;
}
static void xgene_pcie_linkup(struct xgene_pcie_port *port,
u32 *lanes, u32 *speed)
{
u32 val32;
port->link_up = false;
val32 = xgene_pcie_readl(port, PCIECORE_CTLANDSTATUS);
if (val32 & LINK_UP_MASK) {
port->link_up = true;
*speed = PIPE_PHY_RATE_RD(val32);
val32 = xgene_pcie_readl(port, BRIDGE_STATUS_0);
*lanes = val32 >> 26;
}
}
static int xgene_pcie_init_port(struct xgene_pcie_port *port)
{
struct device *dev = port->dev;
int rc;
port->clk = clk_get(dev, NULL);
if (IS_ERR(port->clk)) {
dev_err(dev, "clock not available\n");
return -ENODEV;
}
rc = clk_prepare_enable(port->clk);
if (rc) {
dev_err(dev, "clock enable failed\n");
return rc;
}
return 0;
}
static int xgene_pcie_map_reg(struct xgene_pcie_port *port,
struct platform_device *pdev)
{
struct device *dev = port->dev;
struct resource *res;
res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "csr");
port->csr_base = devm_pci_remap_cfg_resource(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(dev, res);
if (IS_ERR(port->cfg_base))
return PTR_ERR(port->cfg_base);
port->cfg_addr = res->start;
return 0;
}
static void xgene_pcie_setup_ob_reg(struct xgene_pcie_port *port,
struct resource *res, u32 offset,
u64 cpu_addr, u64 pci_addr)
{
struct device *dev = port->dev;
resource_size_t size = resource_size(res);
u64 restype = resource_type(res);
u64 mask = 0;
u32 min_size;
u32 flag = EN_REG;
if (restype == IORESOURCE_MEM) {
min_size = SZ_128M;
} else {
min_size = 128;
flag |= OB_LO_IO;
}
if (size >= min_size)
mask = ~(size - 1) | flag;
else
dev_warn(dev, "res size 0x%llx less than minimum 0x%x\n",
(u64)size, min_size);
xgene_pcie_writel(port, offset, lower_32_bits(cpu_addr));
xgene_pcie_writel(port, offset + 0x04, upper_32_bits(cpu_addr));
xgene_pcie_writel(port, offset + 0x08, lower_32_bits(mask));
xgene_pcie_writel(port, offset + 0x0c, upper_32_bits(mask));
xgene_pcie_writel(port, offset + 0x10, lower_32_bits(pci_addr));
xgene_pcie_writel(port, offset + 0x14, upper_32_bits(pci_addr));
}
static void xgene_pcie_setup_cfg_reg(struct xgene_pcie_port *port)
{
u64 addr = port->cfg_addr;
xgene_pcie_writel(port, CFGBARL, lower_32_bits(addr));
xgene_pcie_writel(port, CFGBARH, upper_32_bits(addr));
xgene_pcie_writel(port, CFGCTL, EN_REG);
}
static int xgene_pcie_map_ranges(struct xgene_pcie_port *port,
struct list_head *res,
resource_size_t io_base)
{
struct resource_entry *window;
struct device *dev = port->dev;
int ret;
resource_list_for_each_entry(window, res) {
struct resource *res = window->res;
u64 restype = resource_type(res);
dev_dbg(dev, "%pR\n", res);
switch (restype) {
case IORESOURCE_IO:
xgene_pcie_setup_ob_reg(port, res, OMR3BARL, io_base,
res->start - window->offset);
ret = pci_remap_iospace(res, io_base);
if (ret < 0)
return ret;
break;
case IORESOURCE_MEM:
if (res->flags & IORESOURCE_PREFETCH)
xgene_pcie_setup_ob_reg(port, res, OMR2BARL,
res->start,
res->start -
window->offset);
else
xgene_pcie_setup_ob_reg(port, res, OMR1BARL,
res->start,
res->start -
window->offset);
break;
case IORESOURCE_BUS:
break;
default:
dev_err(dev, "invalid resource %pR\n", res);
return -EINVAL;
}
}
xgene_pcie_setup_cfg_reg(port);
return 0;
}
static void xgene_pcie_setup_pims(struct xgene_pcie_port *port, u32 pim_reg,
u64 pim, u64 size)
{
xgene_pcie_writel(port, pim_reg, lower_32_bits(pim));
xgene_pcie_writel(port, pim_reg + 0x04,
upper_32_bits(pim) | EN_COHERENCY);
xgene_pcie_writel(port, pim_reg + 0x10, lower_32_bits(size));
xgene_pcie_writel(port, pim_reg + 0x14, upper_32_bits(size));
}
/*
* 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 *cfg_base = port->cfg_base;
struct device *dev = port->dev;
void *bar_addr;
u32 pim_reg;
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(dev, "invalid pcie dma-range config\n");
return;
}
if (range->flags & IORESOURCE_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(port, 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_reg = PIM1_1L;
break;
case 1:
xgene_pcie_writel(port, IBAR2, bar_low);
xgene_pcie_writel(port, IR2MSK, lower_32_bits(mask));
pim_reg = PIM2_1L;
break;
case 2:
xgene_pcie_writel(port, IBAR3L, bar_low);
xgene_pcie_writel(port, IBAR3L + 0x4, upper_32_bits(cpu_addr));
xgene_pcie_writel(port, IR3MSKL, lower_32_bits(mask));
xgene_pcie_writel(port, IR3MSKL + 0x4, upper_32_bits(mask));
pim_reg = PIM3_1L;
break;
}
xgene_pcie_setup_pims(port, pim_reg, pci_addr, ~(size - 1));
}
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 (of_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(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;
}
/* clear BAR configuration which was done by firmware */
static void xgene_pcie_clear_config(struct xgene_pcie_port *port)
{
int i;
for (i = PIM1_1L; i <= CFGCTL; i += 4)
xgene_pcie_writel(port, i, 0);
}
static int xgene_pcie_setup(struct xgene_pcie_port *port, struct list_head *res,
resource_size_t io_base)
{
struct device *dev = port->dev;
u32 val, lanes = 0, speed = 0;
int ret;
xgene_pcie_clear_config(port);
/* setup the vendor and device IDs correctly */
val = (XGENE_PCIE_DEVICEID << 16) | XGENE_PCIE_VENDORID;
xgene_pcie_writel(port, BRIDGE_CFG_0, val);
ret = xgene_pcie_map_ranges(port, res, io_base);
if (ret)
return ret;
ret = xgene_pcie_parse_map_dma_ranges(port);
if (ret)
return ret;
xgene_pcie_linkup(port, &lanes, &speed);
if (!port->link_up)
dev_info(dev, "(rc) link down\n");
else
dev_info(dev, "(rc) x%d gen-%d link up\n", lanes, speed + 1);
return 0;
}
static struct pci_ops xgene_pcie_ops = {
.map_bus = xgene_pcie_map_bus,
.read = xgene_pcie_config_read32,
.write = pci_generic_config_write32,
};
static int xgene_pcie_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct device_node *dn = dev->of_node;
struct xgene_pcie_port *port;
resource_size_t iobase = 0;
struct pci_bus *bus, *child;
struct pci_host_bridge *bridge;
int ret;
LIST_HEAD(res);
bridge = devm_pci_alloc_host_bridge(dev, sizeof(*port));
if (!bridge)
return -ENOMEM;
port = pci_host_bridge_priv(bridge);
port->node = of_node_get(dn);
port->dev = dev;
port->version = XGENE_PCIE_IP_VER_UNKN;
if (of_device_is_compatible(port->node, "apm,xgene-pcie"))
port->version = XGENE_PCIE_IP_VER_1;
ret = xgene_pcie_map_reg(port, pdev);
if (ret)
return ret;
ret = xgene_pcie_init_port(port);
if (ret)
return ret;
ret = of_pci_get_host_bridge_resources(dn, 0, 0xff, &res, &iobase);
if (ret)
return ret;
ret = devm_request_pci_bus_resources(dev, &res);
if (ret)
goto error;
ret = xgene_pcie_setup(port, &res, iobase);
if (ret)
goto error;
list_splice_init(&res, &bridge->windows);
bridge->dev.parent = dev;
bridge->sysdata = port;
bridge->busnr = 0;
bridge->ops = &xgene_pcie_ops;
bridge->map_irq = of_irq_parse_and_map_pci;
bridge->swizzle_irq = pci_common_swizzle;
ret = pci_scan_root_bus_bridge(bridge);
if (ret < 0)
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);
return 0;
error:
pci_free_resource_list(&res);
return ret;
}
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",
.of_match_table = of_match_ptr(xgene_pcie_match_table),
.suppress_bind_attrs = true,
},
.probe = xgene_pcie_probe,
};
builtin_platform_driver(xgene_pcie_driver);
#endif