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linux-stable/drivers/pci/controller/pci-mvebu.c
Pali Rohár c49ae61990 PCI: mvebu: Fix device enumeration regression 
Jan reported that on Turris Omnia (Armada 385), no PCIe devices were
detected after upgrading from v5.16.1 to v5.16.3 and identified the cause
as the backport of 91a8d79fc7 ("PCI: mvebu: Fix configuring secondary bus
of PCIe Root Port via emulated bridge"), which appeared in v5.17-rc1.

91a8d79fc7 was incorrectly applied from mailing list patch [1] to the
linux git repository [2] probably due to resolving merge conflicts
incorrectly. Fix it now.

[1] https://lore.kernel.org/r/20211125124605.25915-12-pali@kernel.org
[2] https://git.kernel.org/linus/91a8d79fc797

[bhelgaas: commit log]
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=215540
Fixes: 91a8d79fc7 ("PCI: mvebu: Fix configuring secondary bus of PCIe Root Port via emulated bridge")
Link: https://lore.kernel.org/r/20220214110228.25825-1-pali@kernel.org
Link: https://lore.kernel.org/r/20220127234917.GA150851@bhelgaas
Reported-by: Jan Palus <jpalus@fastmail.com>
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2022-02-14 09:34:23 -06:00

1418 lines
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// SPDX-License-Identifier: GPL-2.0
/*
* PCIe driver for Marvell Armada 370 and Armada XP SoCs
*
* Author: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/gpio.h>
#include <linux/init.h>
#include <linux/mbus.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/of_gpio.h>
#include <linux/of_pci.h>
#include <linux/of_platform.h>
#include "../pci.h"
#include "../pci-bridge-emul.h"
/*
* PCIe unit register offsets.
*/
#define PCIE_DEV_ID_OFF 0x0000
#define PCIE_CMD_OFF 0x0004
#define PCIE_DEV_REV_OFF 0x0008
#define PCIE_BAR_LO_OFF(n) (0x0010 + ((n) << 3))
#define PCIE_BAR_HI_OFF(n) (0x0014 + ((n) << 3))
#define PCIE_CAP_PCIEXP 0x0060
#define PCIE_HEADER_LOG_4_OFF 0x0128
#define PCIE_BAR_CTRL_OFF(n) (0x1804 + (((n) - 1) * 4))
#define PCIE_WIN04_CTRL_OFF(n) (0x1820 + ((n) << 4))
#define PCIE_WIN04_BASE_OFF(n) (0x1824 + ((n) << 4))
#define PCIE_WIN04_REMAP_OFF(n) (0x182c + ((n) << 4))
#define PCIE_WIN5_CTRL_OFF 0x1880
#define PCIE_WIN5_BASE_OFF 0x1884
#define PCIE_WIN5_REMAP_OFF 0x188c
#define PCIE_CONF_ADDR_OFF 0x18f8
#define PCIE_CONF_ADDR_EN 0x80000000
#define PCIE_CONF_REG(r) ((((r) & 0xf00) << 16) | ((r) & 0xfc))
#define PCIE_CONF_BUS(b) (((b) & 0xff) << 16)
#define PCIE_CONF_DEV(d) (((d) & 0x1f) << 11)
#define PCIE_CONF_FUNC(f) (((f) & 0x7) << 8)
#define PCIE_CONF_ADDR(bus, devfn, where) \
(PCIE_CONF_BUS(bus) | PCIE_CONF_DEV(PCI_SLOT(devfn)) | \
PCIE_CONF_FUNC(PCI_FUNC(devfn)) | PCIE_CONF_REG(where) | \
PCIE_CONF_ADDR_EN)
#define PCIE_CONF_DATA_OFF 0x18fc
#define PCIE_INT_CAUSE_OFF 0x1900
#define PCIE_INT_PM_PME BIT(28)
#define PCIE_MASK_OFF 0x1910
#define PCIE_MASK_ENABLE_INTS 0x0f000000
#define PCIE_CTRL_OFF 0x1a00
#define PCIE_CTRL_X1_MODE 0x0001
#define PCIE_CTRL_RC_MODE BIT(1)
#define PCIE_CTRL_MASTER_HOT_RESET BIT(24)
#define PCIE_STAT_OFF 0x1a04
#define PCIE_STAT_BUS 0xff00
#define PCIE_STAT_DEV 0x1f0000
#define PCIE_STAT_LINK_DOWN BIT(0)
#define PCIE_RC_RTSTA 0x1a14
#define PCIE_DEBUG_CTRL 0x1a60
#define PCIE_DEBUG_SOFT_RESET BIT(20)
struct mvebu_pcie_port;
/* Structure representing all PCIe interfaces */
struct mvebu_pcie {
struct platform_device *pdev;
struct mvebu_pcie_port *ports;
struct resource io;
struct resource realio;
struct resource mem;
struct resource busn;
int nports;
};
struct mvebu_pcie_window {
phys_addr_t base;
phys_addr_t remap;
size_t size;
};
/* Structure representing one PCIe interface */
struct mvebu_pcie_port {
char *name;
void __iomem *base;
u32 port;
u32 lane;
int devfn;
unsigned int mem_target;
unsigned int mem_attr;
unsigned int io_target;
unsigned int io_attr;
struct clk *clk;
struct gpio_desc *reset_gpio;
char *reset_name;
struct pci_bridge_emul bridge;
struct device_node *dn;
struct mvebu_pcie *pcie;
struct mvebu_pcie_window memwin;
struct mvebu_pcie_window iowin;
u32 saved_pcie_stat;
struct resource regs;
};
static inline void mvebu_writel(struct mvebu_pcie_port *port, u32 val, u32 reg)
{
writel(val, port->base + reg);
}
static inline u32 mvebu_readl(struct mvebu_pcie_port *port, u32 reg)
{
return readl(port->base + reg);
}
static inline bool mvebu_has_ioport(struct mvebu_pcie_port *port)
{
return port->io_target != -1 && port->io_attr != -1;
}
static bool mvebu_pcie_link_up(struct mvebu_pcie_port *port)
{
return !(mvebu_readl(port, PCIE_STAT_OFF) & PCIE_STAT_LINK_DOWN);
}
static u8 mvebu_pcie_get_local_bus_nr(struct mvebu_pcie_port *port)
{
return (mvebu_readl(port, PCIE_STAT_OFF) & PCIE_STAT_BUS) >> 8;
}
static void mvebu_pcie_set_local_bus_nr(struct mvebu_pcie_port *port, int nr)
{
u32 stat;
stat = mvebu_readl(port, PCIE_STAT_OFF);
stat &= ~PCIE_STAT_BUS;
stat |= nr << 8;
mvebu_writel(port, stat, PCIE_STAT_OFF);
}
static void mvebu_pcie_set_local_dev_nr(struct mvebu_pcie_port *port, int nr)
{
u32 stat;
stat = mvebu_readl(port, PCIE_STAT_OFF);
stat &= ~PCIE_STAT_DEV;
stat |= nr << 16;
mvebu_writel(port, stat, PCIE_STAT_OFF);
}
static void mvebu_pcie_disable_wins(struct mvebu_pcie_port *port)
{
int i;
mvebu_writel(port, 0, PCIE_BAR_LO_OFF(0));
mvebu_writel(port, 0, PCIE_BAR_HI_OFF(0));
for (i = 1; i < 3; i++) {
mvebu_writel(port, 0, PCIE_BAR_CTRL_OFF(i));
mvebu_writel(port, 0, PCIE_BAR_LO_OFF(i));
mvebu_writel(port, 0, PCIE_BAR_HI_OFF(i));
}
for (i = 0; i < 5; i++) {
mvebu_writel(port, 0, PCIE_WIN04_CTRL_OFF(i));
mvebu_writel(port, 0, PCIE_WIN04_BASE_OFF(i));
mvebu_writel(port, 0, PCIE_WIN04_REMAP_OFF(i));
}
mvebu_writel(port, 0, PCIE_WIN5_CTRL_OFF);
mvebu_writel(port, 0, PCIE_WIN5_BASE_OFF);
mvebu_writel(port, 0, PCIE_WIN5_REMAP_OFF);
}
/*
* Setup PCIE BARs and Address Decode Wins:
* BAR[0] -> internal registers (needed for MSI)
* BAR[1] -> covers all DRAM banks
* BAR[2] -> Disabled
* WIN[0-3] -> DRAM bank[0-3]
*/
static void mvebu_pcie_setup_wins(struct mvebu_pcie_port *port)
{
const struct mbus_dram_target_info *dram;
u32 size;
int i;
dram = mv_mbus_dram_info();
/* First, disable and clear BARs and windows. */
mvebu_pcie_disable_wins(port);
/* Setup windows for DDR banks. Count total DDR size on the fly. */
size = 0;
for (i = 0; i < dram->num_cs; i++) {
const struct mbus_dram_window *cs = dram->cs + i;
mvebu_writel(port, cs->base & 0xffff0000,
PCIE_WIN04_BASE_OFF(i));
mvebu_writel(port, 0, PCIE_WIN04_REMAP_OFF(i));
mvebu_writel(port,
((cs->size - 1) & 0xffff0000) |
(cs->mbus_attr << 8) |
(dram->mbus_dram_target_id << 4) | 1,
PCIE_WIN04_CTRL_OFF(i));
size += cs->size;
}
/* Round up 'size' to the nearest power of two. */
if ((size & (size - 1)) != 0)
size = 1 << fls(size);
/* Setup BAR[1] to all DRAM banks. */
mvebu_writel(port, dram->cs[0].base, PCIE_BAR_LO_OFF(1));
mvebu_writel(port, 0, PCIE_BAR_HI_OFF(1));
mvebu_writel(port, ((size - 1) & 0xffff0000) | 1,
PCIE_BAR_CTRL_OFF(1));
/*
* Point BAR[0] to the device's internal registers.
*/
mvebu_writel(port, round_down(port->regs.start, SZ_1M), PCIE_BAR_LO_OFF(0));
mvebu_writel(port, 0, PCIE_BAR_HI_OFF(0));
}
static void mvebu_pcie_setup_hw(struct mvebu_pcie_port *port)
{
u32 ctrl, cmd, dev_rev, mask;
/* Setup PCIe controller to Root Complex mode. */
ctrl = mvebu_readl(port, PCIE_CTRL_OFF);
ctrl |= PCIE_CTRL_RC_MODE;
mvebu_writel(port, ctrl, PCIE_CTRL_OFF);
/* Disable Root Bridge I/O space, memory space and bus mastering. */
cmd = mvebu_readl(port, PCIE_CMD_OFF);
cmd &= ~(PCI_COMMAND_IO | PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER);
mvebu_writel(port, cmd, PCIE_CMD_OFF);
/*
* Change Class Code of PCI Bridge device to PCI Bridge (0x6004)
* because default value is Memory controller (0x5080).
*
* Note that this mvebu PCI Bridge does not have compliant Type 1
* Configuration Space. Header Type is reported as Type 0 and it
* has format of Type 0 config space.
*
* Moreover Type 0 BAR registers (ranges 0x10 - 0x28 and 0x30 - 0x34)
* have the same format in Marvell's specification as in PCIe
* specification, but their meaning is totally different and they do
* different things: they are aliased into internal mvebu registers
* (e.g. PCIE_BAR_LO_OFF) and these should not be changed or
* reconfigured by pci device drivers.
*
* Therefore driver uses emulation of PCI Bridge which emulates
* access to configuration space via internal mvebu registers or
* emulated configuration buffer. Driver access these PCI Bridge
* directly for simplification, but these registers can be accessed
* also via standard mvebu way for accessing PCI config space.
*/
dev_rev = mvebu_readl(port, PCIE_DEV_REV_OFF);
dev_rev &= ~0xffffff00;
dev_rev |= (PCI_CLASS_BRIDGE_PCI << 8) << 8;
mvebu_writel(port, dev_rev, PCIE_DEV_REV_OFF);
/* Point PCIe unit MBUS decode windows to DRAM space. */
mvebu_pcie_setup_wins(port);
/* Enable interrupt lines A-D. */
mask = mvebu_readl(port, PCIE_MASK_OFF);
mask |= PCIE_MASK_ENABLE_INTS;
mvebu_writel(port, mask, PCIE_MASK_OFF);
}
static int mvebu_pcie_hw_rd_conf(struct mvebu_pcie_port *port,
struct pci_bus *bus,
u32 devfn, int where, int size, u32 *val)
{
void __iomem *conf_data = port->base + PCIE_CONF_DATA_OFF;
mvebu_writel(port, PCIE_CONF_ADDR(bus->number, devfn, where),
PCIE_CONF_ADDR_OFF);
switch (size) {
case 1:
*val = readb_relaxed(conf_data + (where & 3));
break;
case 2:
*val = readw_relaxed(conf_data + (where & 2));
break;
case 4:
*val = readl_relaxed(conf_data);
break;
default:
*val = 0xffffffff;
return PCIBIOS_BAD_REGISTER_NUMBER;
}
return PCIBIOS_SUCCESSFUL;
}
static int mvebu_pcie_hw_wr_conf(struct mvebu_pcie_port *port,
struct pci_bus *bus,
u32 devfn, int where, int size, u32 val)
{
void __iomem *conf_data = port->base + PCIE_CONF_DATA_OFF;
mvebu_writel(port, PCIE_CONF_ADDR(bus->number, devfn, where),
PCIE_CONF_ADDR_OFF);
switch (size) {
case 1:
writeb(val, conf_data + (where & 3));
break;
case 2:
writew(val, conf_data + (where & 2));
break;
case 4:
writel(val, conf_data);
break;
default:
return PCIBIOS_BAD_REGISTER_NUMBER;
}
return PCIBIOS_SUCCESSFUL;
}
/*
* Remove windows, starting from the largest ones to the smallest
* ones.
*/
static void mvebu_pcie_del_windows(struct mvebu_pcie_port *port,
phys_addr_t base, size_t size)
{
while (size) {
size_t sz = 1 << (fls(size) - 1);
mvebu_mbus_del_window(base, sz);
base += sz;
size -= sz;
}
}
/*
* MBus windows can only have a power of two size, but PCI BARs do not
* have this constraint. Therefore, we have to split the PCI BAR into
* areas each having a power of two size. We start from the largest
* one (i.e highest order bit set in the size).
*/
static int mvebu_pcie_add_windows(struct mvebu_pcie_port *port,
unsigned int target, unsigned int attribute,
phys_addr_t base, size_t size,
phys_addr_t remap)
{
size_t size_mapped = 0;
while (size) {
size_t sz = 1 << (fls(size) - 1);
int ret;
ret = mvebu_mbus_add_window_remap_by_id(target, attribute, base,
sz, remap);
if (ret) {
phys_addr_t end = base + sz - 1;
dev_err(&port->pcie->pdev->dev,
"Could not create MBus window at [mem %pa-%pa]: %d\n",
&base, &end, ret);
mvebu_pcie_del_windows(port, base - size_mapped,
size_mapped);
return ret;
}
size -= sz;
size_mapped += sz;
base += sz;
if (remap != MVEBU_MBUS_NO_REMAP)
remap += sz;
}
return 0;
}
static int mvebu_pcie_set_window(struct mvebu_pcie_port *port,
unsigned int target, unsigned int attribute,
const struct mvebu_pcie_window *desired,
struct mvebu_pcie_window *cur)
{
int ret;
if (desired->base == cur->base && desired->remap == cur->remap &&
desired->size == cur->size)
return 0;
if (cur->size != 0) {
mvebu_pcie_del_windows(port, cur->base, cur->size);
cur->size = 0;
cur->base = 0;
/*
* If something tries to change the window while it is enabled
* the change will not be done atomically. That would be
* difficult to do in the general case.
*/
}
if (desired->size == 0)
return 0;
ret = mvebu_pcie_add_windows(port, target, attribute, desired->base,
desired->size, desired->remap);
if (ret) {
cur->size = 0;
cur->base = 0;
return ret;
}
*cur = *desired;
return 0;
}
static int mvebu_pcie_handle_iobase_change(struct mvebu_pcie_port *port)
{
struct mvebu_pcie_window desired = {};
struct pci_bridge_emul_conf *conf = &port->bridge.conf;
/* Are the new iobase/iolimit values invalid? */
if (conf->iolimit < conf->iobase ||
conf->iolimitupper < conf->iobaseupper)
return mvebu_pcie_set_window(port, port->io_target, port->io_attr,
&desired, &port->iowin);
if (!mvebu_has_ioport(port)) {
dev_WARN(&port->pcie->pdev->dev,
"Attempt to set IO when IO is disabled\n");
return -EOPNOTSUPP;
}
/*
* We read the PCI-to-PCI bridge emulated registers, and
* calculate the base address and size of the address decoding
* window to setup, according to the PCI-to-PCI bridge
* specifications. iobase is the bus address, port->iowin_base
* is the CPU address.
*/
desired.remap = ((conf->iobase & 0xF0) << 8) |
(conf->iobaseupper << 16);
desired.base = port->pcie->io.start + desired.remap;
desired.size = ((0xFFF | ((conf->iolimit & 0xF0) << 8) |
(conf->iolimitupper << 16)) -
desired.remap) +
1;
return mvebu_pcie_set_window(port, port->io_target, port->io_attr, &desired,
&port->iowin);
}
static int mvebu_pcie_handle_membase_change(struct mvebu_pcie_port *port)
{
struct mvebu_pcie_window desired = {.remap = MVEBU_MBUS_NO_REMAP};
struct pci_bridge_emul_conf *conf = &port->bridge.conf;
/* Are the new membase/memlimit values invalid? */
if (conf->memlimit < conf->membase)
return mvebu_pcie_set_window(port, port->mem_target, port->mem_attr,
&desired, &port->memwin);
/*
* We read the PCI-to-PCI bridge emulated registers, and
* calculate the base address and size of the address decoding
* window to setup, according to the PCI-to-PCI bridge
* specifications.
*/
desired.base = ((conf->membase & 0xFFF0) << 16);
desired.size = (((conf->memlimit & 0xFFF0) << 16) | 0xFFFFF) -
desired.base + 1;
return mvebu_pcie_set_window(port, port->mem_target, port->mem_attr, &desired,
&port->memwin);
}
static pci_bridge_emul_read_status_t
mvebu_pci_bridge_emul_base_conf_read(struct pci_bridge_emul *bridge,
int reg, u32 *value)
{
struct mvebu_pcie_port *port = bridge->data;
switch (reg) {
case PCI_COMMAND:
*value = mvebu_readl(port, PCIE_CMD_OFF);
break;
case PCI_PRIMARY_BUS: {
/*
* From the whole 32bit register we support reading from HW only
* secondary bus number which is mvebu local bus number.
* Other bits are retrieved only from emulated config buffer.
*/
__le32 *cfgspace = (__le32 *)&bridge->conf;
u32 val = le32_to_cpu(cfgspace[PCI_PRIMARY_BUS / 4]);
val &= ~0xff00;
val |= mvebu_pcie_get_local_bus_nr(port) << 8;
*value = val;
break;
}
case PCI_INTERRUPT_LINE: {
/*
* From the whole 32bit register we support reading from HW only
* one bit: PCI_BRIDGE_CTL_BUS_RESET.
* Other bits are retrieved only from emulated config buffer.
*/
__le32 *cfgspace = (__le32 *)&bridge->conf;
u32 val = le32_to_cpu(cfgspace[PCI_INTERRUPT_LINE / 4]);
if (mvebu_readl(port, PCIE_CTRL_OFF) & PCIE_CTRL_MASTER_HOT_RESET)
val |= PCI_BRIDGE_CTL_BUS_RESET << 16;
else
val &= ~(PCI_BRIDGE_CTL_BUS_RESET << 16);
*value = val;
break;
}
default:
return PCI_BRIDGE_EMUL_NOT_HANDLED;
}
return PCI_BRIDGE_EMUL_HANDLED;
}
static pci_bridge_emul_read_status_t
mvebu_pci_bridge_emul_pcie_conf_read(struct pci_bridge_emul *bridge,
int reg, u32 *value)
{
struct mvebu_pcie_port *port = bridge->data;
switch (reg) {
case PCI_EXP_DEVCAP:
*value = mvebu_readl(port, PCIE_CAP_PCIEXP + PCI_EXP_DEVCAP);
break;
case PCI_EXP_DEVCTL:
*value = mvebu_readl(port, PCIE_CAP_PCIEXP + PCI_EXP_DEVCTL);
break;
case PCI_EXP_LNKCAP:
/*
* PCIe requires the clock power management capability to be
* hard-wired to zero for downstream ports
*/
*value = mvebu_readl(port, PCIE_CAP_PCIEXP + PCI_EXP_LNKCAP) &
~PCI_EXP_LNKCAP_CLKPM;
break;
case PCI_EXP_LNKCTL:
*value = mvebu_readl(port, PCIE_CAP_PCIEXP + PCI_EXP_LNKCTL);
break;
case PCI_EXP_SLTCTL:
*value = PCI_EXP_SLTSTA_PDS << 16;
break;
case PCI_EXP_RTSTA:
*value = mvebu_readl(port, PCIE_RC_RTSTA);
break;
case PCI_EXP_DEVCAP2:
*value = mvebu_readl(port, PCIE_CAP_PCIEXP + PCI_EXP_DEVCAP2);
break;
case PCI_EXP_DEVCTL2:
*value = mvebu_readl(port, PCIE_CAP_PCIEXP + PCI_EXP_DEVCTL2);
break;
case PCI_EXP_LNKCTL2:
*value = mvebu_readl(port, PCIE_CAP_PCIEXP + PCI_EXP_LNKCTL2);
break;
default:
return PCI_BRIDGE_EMUL_NOT_HANDLED;
}
return PCI_BRIDGE_EMUL_HANDLED;
}
static void
mvebu_pci_bridge_emul_base_conf_write(struct pci_bridge_emul *bridge,
int reg, u32 old, u32 new, u32 mask)
{
struct mvebu_pcie_port *port = bridge->data;
struct pci_bridge_emul_conf *conf = &bridge->conf;
switch (reg) {
case PCI_COMMAND:
if (!mvebu_has_ioport(port)) {
conf->command = cpu_to_le16(
le16_to_cpu(conf->command) & ~PCI_COMMAND_IO);
new &= ~PCI_COMMAND_IO;
}
mvebu_writel(port, new, PCIE_CMD_OFF);
break;
case PCI_IO_BASE:
if ((mask & 0xffff) && mvebu_pcie_handle_iobase_change(port)) {
/* On error disable IO range */
conf->iobase &= ~0xf0;
conf->iolimit &= ~0xf0;
conf->iobaseupper = cpu_to_le16(0x0000);
conf->iolimitupper = cpu_to_le16(0x0000);
if (mvebu_has_ioport(port))
conf->iobase |= 0xf0;
}
break;
case PCI_MEMORY_BASE:
if (mvebu_pcie_handle_membase_change(port)) {
/* On error disable mem range */
conf->membase = cpu_to_le16(le16_to_cpu(conf->membase) & ~0xfff0);
conf->memlimit = cpu_to_le16(le16_to_cpu(conf->memlimit) & ~0xfff0);
conf->membase = cpu_to_le16(le16_to_cpu(conf->membase) | 0xfff0);
}
break;
case PCI_IO_BASE_UPPER16:
if (mvebu_pcie_handle_iobase_change(port)) {
/* On error disable IO range */
conf->iobase &= ~0xf0;
conf->iolimit &= ~0xf0;
conf->iobaseupper = cpu_to_le16(0x0000);
conf->iolimitupper = cpu_to_le16(0x0000);
if (mvebu_has_ioport(port))
conf->iobase |= 0xf0;
}
break;
case PCI_PRIMARY_BUS:
if (mask & 0xff00)
mvebu_pcie_set_local_bus_nr(port, conf->secondary_bus);
break;
case PCI_INTERRUPT_LINE:
if (mask & (PCI_BRIDGE_CTL_BUS_RESET << 16)) {
u32 ctrl = mvebu_readl(port, PCIE_CTRL_OFF);
if (new & (PCI_BRIDGE_CTL_BUS_RESET << 16))
ctrl |= PCIE_CTRL_MASTER_HOT_RESET;
else
ctrl &= ~PCIE_CTRL_MASTER_HOT_RESET;
mvebu_writel(port, ctrl, PCIE_CTRL_OFF);
}
break;
default:
break;
}
}
static void
mvebu_pci_bridge_emul_pcie_conf_write(struct pci_bridge_emul *bridge,
int reg, u32 old, u32 new, u32 mask)
{
struct mvebu_pcie_port *port = bridge->data;
switch (reg) {
case PCI_EXP_DEVCTL:
mvebu_writel(port, new, PCIE_CAP_PCIEXP + PCI_EXP_DEVCTL);
break;
case PCI_EXP_LNKCTL:
/*
* If we don't support CLKREQ, we must ensure that the
* CLKREQ enable bit always reads zero. Since we haven't
* had this capability, and it's dependent on board wiring,
* disable it for the time being.
*/
new &= ~PCI_EXP_LNKCTL_CLKREQ_EN;
mvebu_writel(port, new, PCIE_CAP_PCIEXP + PCI_EXP_LNKCTL);
break;
case PCI_EXP_RTSTA:
/*
* PME Status bit in Root Status Register (PCIE_RC_RTSTA)
* is read-only and can be cleared only by writing 0b to the
* Interrupt Cause RW0C register (PCIE_INT_CAUSE_OFF). So
* clear PME via Interrupt Cause.
*/
if (new & PCI_EXP_RTSTA_PME)
mvebu_writel(port, ~PCIE_INT_PM_PME, PCIE_INT_CAUSE_OFF);
break;
case PCI_EXP_DEVCTL2:
mvebu_writel(port, new, PCIE_CAP_PCIEXP + PCI_EXP_DEVCTL2);
break;
case PCI_EXP_LNKCTL2:
mvebu_writel(port, new, PCIE_CAP_PCIEXP + PCI_EXP_LNKCTL2);
break;
default:
break;
}
}
static struct pci_bridge_emul_ops mvebu_pci_bridge_emul_ops = {
.read_base = mvebu_pci_bridge_emul_base_conf_read,
.write_base = mvebu_pci_bridge_emul_base_conf_write,
.read_pcie = mvebu_pci_bridge_emul_pcie_conf_read,
.write_pcie = mvebu_pci_bridge_emul_pcie_conf_write,
};
/*
* Initialize the configuration space of the PCI-to-PCI bridge
* associated with the given PCIe interface.
*/
static int mvebu_pci_bridge_emul_init(struct mvebu_pcie_port *port)
{
struct pci_bridge_emul *bridge = &port->bridge;
u32 pcie_cap = mvebu_readl(port, PCIE_CAP_PCIEXP);
u8 pcie_cap_ver = ((pcie_cap >> 16) & PCI_EXP_FLAGS_VERS);
bridge->conf.vendor = PCI_VENDOR_ID_MARVELL;
bridge->conf.device = mvebu_readl(port, PCIE_DEV_ID_OFF) >> 16;
bridge->conf.class_revision =
mvebu_readl(port, PCIE_DEV_REV_OFF) & 0xff;
if (mvebu_has_ioport(port)) {
/* We support 32 bits I/O addressing */
bridge->conf.iobase = PCI_IO_RANGE_TYPE_32;
bridge->conf.iolimit = PCI_IO_RANGE_TYPE_32;
}
/*
* Older mvebu hardware provides PCIe Capability structure only in
* version 1. New hardware provides it in version 2.
*/
bridge->pcie_conf.cap = cpu_to_le16(pcie_cap_ver);
bridge->has_pcie = true;
bridge->data = port;
bridge->ops = &mvebu_pci_bridge_emul_ops;
return pci_bridge_emul_init(bridge, PCI_BRIDGE_EMUL_NO_PREFETCHABLE_BAR);
}
static inline struct mvebu_pcie *sys_to_pcie(struct pci_sys_data *sys)
{
return sys->private_data;
}
static struct mvebu_pcie_port *mvebu_pcie_find_port(struct mvebu_pcie *pcie,
struct pci_bus *bus,
int devfn)
{
int i;
for (i = 0; i < pcie->nports; i++) {
struct mvebu_pcie_port *port = &pcie->ports[i];
if (!port->base)
continue;
if (bus->number == 0 && port->devfn == devfn)
return port;
if (bus->number != 0 &&
bus->number >= port->bridge.conf.secondary_bus &&
bus->number <= port->bridge.conf.subordinate_bus)
return port;
}
return NULL;
}
/* PCI configuration space write function */
static int mvebu_pcie_wr_conf(struct pci_bus *bus, u32 devfn,
int where, int size, u32 val)
{
struct mvebu_pcie *pcie = bus->sysdata;
struct mvebu_pcie_port *port;
int ret;
port = mvebu_pcie_find_port(pcie, bus, devfn);
if (!port)
return PCIBIOS_DEVICE_NOT_FOUND;
/* Access the emulated PCI-to-PCI bridge */
if (bus->number == 0)
return pci_bridge_emul_conf_write(&port->bridge, where,
size, val);
if (!mvebu_pcie_link_up(port))
return PCIBIOS_DEVICE_NOT_FOUND;
/* Access the real PCIe interface */
ret = mvebu_pcie_hw_wr_conf(port, bus, devfn,
where, size, val);
return ret;
}
/* PCI configuration space read function */
static int mvebu_pcie_rd_conf(struct pci_bus *bus, u32 devfn, int where,
int size, u32 *val)
{
struct mvebu_pcie *pcie = bus->sysdata;
struct mvebu_pcie_port *port;
int ret;
port = mvebu_pcie_find_port(pcie, bus, devfn);
if (!port)
return PCIBIOS_DEVICE_NOT_FOUND;
/* Access the emulated PCI-to-PCI bridge */
if (bus->number == 0)
return pci_bridge_emul_conf_read(&port->bridge, where,
size, val);
if (!mvebu_pcie_link_up(port))
return PCIBIOS_DEVICE_NOT_FOUND;
/* Access the real PCIe interface */
ret = mvebu_pcie_hw_rd_conf(port, bus, devfn,
where, size, val);
return ret;
}
static struct pci_ops mvebu_pcie_ops = {
.read = mvebu_pcie_rd_conf,
.write = mvebu_pcie_wr_conf,
};
static int mvebu_pcie_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
{
/* Interrupt support on mvebu emulated bridges is not implemented yet */
if (dev->bus->number == 0)
return 0; /* Proper return code 0 == NO_IRQ */
return of_irq_parse_and_map_pci(dev, slot, pin);
}
static resource_size_t mvebu_pcie_align_resource(struct pci_dev *dev,
const struct resource *res,
resource_size_t start,
resource_size_t size,
resource_size_t align)
{
if (dev->bus->number != 0)
return start;
/*
* On the PCI-to-PCI bridge side, the I/O windows must have at
* least a 64 KB size and the memory windows must have at
* least a 1 MB size. Moreover, MBus windows need to have a
* base address aligned on their size, and their size must be
* a power of two. This means that if the BAR doesn't have a
* power of two size, several MBus windows will actually be
* created. We need to ensure that the biggest MBus window
* (which will be the first one) is aligned on its size, which
* explains the rounddown_pow_of_two() being done here.
*/
if (res->flags & IORESOURCE_IO)
return round_up(start, max_t(resource_size_t, SZ_64K,
rounddown_pow_of_two(size)));
else if (res->flags & IORESOURCE_MEM)
return round_up(start, max_t(resource_size_t, SZ_1M,
rounddown_pow_of_two(size)));
else
return start;
}
static void __iomem *mvebu_pcie_map_registers(struct platform_device *pdev,
struct device_node *np,
struct mvebu_pcie_port *port)
{
int ret = 0;
ret = of_address_to_resource(np, 0, &port->regs);
if (ret)
return (void __iomem *)ERR_PTR(ret);
return devm_ioremap_resource(&pdev->dev, &port->regs);
}
#define DT_FLAGS_TO_TYPE(flags) (((flags) >> 24) & 0x03)
#define DT_TYPE_IO 0x1
#define DT_TYPE_MEM32 0x2
#define DT_CPUADDR_TO_TARGET(cpuaddr) (((cpuaddr) >> 56) & 0xFF)
#define DT_CPUADDR_TO_ATTR(cpuaddr) (((cpuaddr) >> 48) & 0xFF)
static int mvebu_get_tgt_attr(struct device_node *np, int devfn,
unsigned long type,
unsigned int *tgt,
unsigned int *attr)
{
const int na = 3, ns = 2;
const __be32 *range;
int rlen, nranges, rangesz, pna, i;
*tgt = -1;
*attr = -1;
range = of_get_property(np, "ranges", &rlen);
if (!range)
return -EINVAL;
pna = of_n_addr_cells(np);
rangesz = pna + na + ns;
nranges = rlen / sizeof(__be32) / rangesz;
for (i = 0; i < nranges; i++, range += rangesz) {
u32 flags = of_read_number(range, 1);
u32 slot = of_read_number(range + 1, 1);
u64 cpuaddr = of_read_number(range + na, pna);
unsigned long rtype;
if (DT_FLAGS_TO_TYPE(flags) == DT_TYPE_IO)
rtype = IORESOURCE_IO;
else if (DT_FLAGS_TO_TYPE(flags) == DT_TYPE_MEM32)
rtype = IORESOURCE_MEM;
else
continue;
if (slot == PCI_SLOT(devfn) && type == rtype) {
*tgt = DT_CPUADDR_TO_TARGET(cpuaddr);
*attr = DT_CPUADDR_TO_ATTR(cpuaddr);
return 0;
}
}
return -ENOENT;
}
#ifdef CONFIG_PM_SLEEP
static int mvebu_pcie_suspend(struct device *dev)
{
struct mvebu_pcie *pcie;
int i;
pcie = dev_get_drvdata(dev);
for (i = 0; i < pcie->nports; i++) {
struct mvebu_pcie_port *port = pcie->ports + i;
if (!port->base)
continue;
port->saved_pcie_stat = mvebu_readl(port, PCIE_STAT_OFF);
}
return 0;
}
static int mvebu_pcie_resume(struct device *dev)
{
struct mvebu_pcie *pcie;
int i;
pcie = dev_get_drvdata(dev);
for (i = 0; i < pcie->nports; i++) {
struct mvebu_pcie_port *port = pcie->ports + i;
if (!port->base)
continue;
mvebu_writel(port, port->saved_pcie_stat, PCIE_STAT_OFF);
mvebu_pcie_setup_hw(port);
}
return 0;
}
#endif
static void mvebu_pcie_port_clk_put(void *data)
{
struct mvebu_pcie_port *port = data;
clk_put(port->clk);
}
static int mvebu_pcie_parse_port(struct mvebu_pcie *pcie,
struct mvebu_pcie_port *port, struct device_node *child)
{
struct device *dev = &pcie->pdev->dev;
enum of_gpio_flags flags;
int reset_gpio, ret;
port->pcie = pcie;
if (of_property_read_u32(child, "marvell,pcie-port", &port->port)) {
dev_warn(dev, "ignoring %pOF, missing pcie-port property\n",
child);
goto skip;
}
if (of_property_read_u32(child, "marvell,pcie-lane", &port->lane))
port->lane = 0;
port->name = devm_kasprintf(dev, GFP_KERNEL, "pcie%d.%d", port->port,
port->lane);
if (!port->name) {
ret = -ENOMEM;
goto err;
}
port->devfn = of_pci_get_devfn(child);
if (port->devfn < 0)
goto skip;
if (PCI_FUNC(port->devfn) != 0) {
dev_err(dev, "%s: invalid function number, must be zero\n",
port->name);
goto skip;
}
ret = mvebu_get_tgt_attr(dev->of_node, port->devfn, IORESOURCE_MEM,
&port->mem_target, &port->mem_attr);
if (ret < 0) {
dev_err(dev, "%s: cannot get tgt/attr for mem window\n",
port->name);
goto skip;
}
if (resource_size(&pcie->io) != 0) {
mvebu_get_tgt_attr(dev->of_node, port->devfn, IORESOURCE_IO,
&port->io_target, &port->io_attr);
} else {
port->io_target = -1;
port->io_attr = -1;
}
reset_gpio = of_get_named_gpio_flags(child, "reset-gpios", 0, &flags);
if (reset_gpio == -EPROBE_DEFER) {
ret = reset_gpio;
goto err;
}
if (gpio_is_valid(reset_gpio)) {
unsigned long gpio_flags;
port->reset_name = devm_kasprintf(dev, GFP_KERNEL, "%s-reset",
port->name);
if (!port->reset_name) {
ret = -ENOMEM;
goto err;
}
if (flags & OF_GPIO_ACTIVE_LOW) {
dev_info(dev, "%pOF: reset gpio is active low\n",
child);
gpio_flags = GPIOF_ACTIVE_LOW |
GPIOF_OUT_INIT_LOW;
} else {
gpio_flags = GPIOF_OUT_INIT_HIGH;
}
ret = devm_gpio_request_one(dev, reset_gpio, gpio_flags,
port->reset_name);
if (ret) {
if (ret == -EPROBE_DEFER)
goto err;
goto skip;
}
port->reset_gpio = gpio_to_desc(reset_gpio);
}
port->clk = of_clk_get_by_name(child, NULL);
if (IS_ERR(port->clk)) {
dev_err(dev, "%s: cannot get clock\n", port->name);
goto skip;
}
ret = devm_add_action(dev, mvebu_pcie_port_clk_put, port);
if (ret < 0) {
clk_put(port->clk);
goto err;
}
return 1;
skip:
ret = 0;
/* In the case of skipping, we need to free these */
devm_kfree(dev, port->reset_name);
port->reset_name = NULL;
devm_kfree(dev, port->name);
port->name = NULL;
err:
return ret;
}
/*
* Power up a PCIe port. PCIe requires the refclk to be stable for 100µs
* prior to releasing PERST. See table 2-4 in section 2.6.2 AC Specifications
* of the PCI Express Card Electromechanical Specification, 1.1.
*/
static int mvebu_pcie_powerup(struct mvebu_pcie_port *port)
{
int ret;
ret = clk_prepare_enable(port->clk);
if (ret < 0)
return ret;
if (port->reset_gpio) {
u32 reset_udelay = PCI_PM_D3COLD_WAIT * 1000;
of_property_read_u32(port->dn, "reset-delay-us",
&reset_udelay);
udelay(100);
gpiod_set_value_cansleep(port->reset_gpio, 0);
msleep(reset_udelay / 1000);
}
return 0;
}
/*
* Power down a PCIe port. Strictly, PCIe requires us to place the card
* in D3hot state before asserting PERST#.
*/
static void mvebu_pcie_powerdown(struct mvebu_pcie_port *port)
{
gpiod_set_value_cansleep(port->reset_gpio, 1);
clk_disable_unprepare(port->clk);
}
/*
* devm_of_pci_get_host_bridge_resources() only sets up translateable resources,
* so we need extra resource setup parsing our special DT properties encoding
* the MEM and IO apertures.
*/
static int mvebu_pcie_parse_request_resources(struct mvebu_pcie *pcie)
{
struct device *dev = &pcie->pdev->dev;
struct pci_host_bridge *bridge = pci_host_bridge_from_priv(pcie);
int ret;
/* Get the PCIe memory aperture */
mvebu_mbus_get_pcie_mem_aperture(&pcie->mem);
if (resource_size(&pcie->mem) == 0) {
dev_err(dev, "invalid memory aperture size\n");
return -EINVAL;
}
pcie->mem.name = "PCI MEM";
pci_add_resource(&bridge->windows, &pcie->mem);
ret = devm_request_resource(dev, &iomem_resource, &pcie->mem);
if (ret)
return ret;
/* Get the PCIe IO aperture */
mvebu_mbus_get_pcie_io_aperture(&pcie->io);
if (resource_size(&pcie->io) != 0) {
pcie->realio.flags = pcie->io.flags;
pcie->realio.start = PCIBIOS_MIN_IO;
pcie->realio.end = min_t(resource_size_t,
IO_SPACE_LIMIT - SZ_64K,
resource_size(&pcie->io) - 1);
pcie->realio.name = "PCI I/O";
ret = devm_pci_remap_iospace(dev, &pcie->realio, pcie->io.start);
if (ret)
return ret;
pci_add_resource(&bridge->windows, &pcie->realio);
ret = devm_request_resource(dev, &ioport_resource, &pcie->realio);
if (ret)
return ret;
}
return 0;
}
static int mvebu_pcie_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct mvebu_pcie *pcie;
struct pci_host_bridge *bridge;
struct device_node *np = dev->of_node;
struct device_node *child;
int num, i, ret;
bridge = devm_pci_alloc_host_bridge(dev, sizeof(struct mvebu_pcie));
if (!bridge)
return -ENOMEM;
pcie = pci_host_bridge_priv(bridge);
pcie->pdev = pdev;
platform_set_drvdata(pdev, pcie);
ret = mvebu_pcie_parse_request_resources(pcie);
if (ret)
return ret;
num = of_get_available_child_count(np);
pcie->ports = devm_kcalloc(dev, num, sizeof(*pcie->ports), GFP_KERNEL);
if (!pcie->ports)
return -ENOMEM;
i = 0;
for_each_available_child_of_node(np, child) {
struct mvebu_pcie_port *port = &pcie->ports[i];
ret = mvebu_pcie_parse_port(pcie, port, child);
if (ret < 0) {
of_node_put(child);
return ret;
} else if (ret == 0) {
continue;
}
port->dn = child;
i++;
}
pcie->nports = i;
for (i = 0; i < pcie->nports; i++) {
struct mvebu_pcie_port *port = &pcie->ports[i];
child = port->dn;
if (!child)
continue;
ret = mvebu_pcie_powerup(port);
if (ret < 0)
continue;
port->base = mvebu_pcie_map_registers(pdev, child, port);
if (IS_ERR(port->base)) {
dev_err(dev, "%s: cannot map registers\n", port->name);
port->base = NULL;
mvebu_pcie_powerdown(port);
continue;
}
ret = mvebu_pci_bridge_emul_init(port);
if (ret < 0) {
dev_err(dev, "%s: cannot init emulated bridge\n",
port->name);
devm_iounmap(dev, port->base);
port->base = NULL;
mvebu_pcie_powerdown(port);
continue;
}
/*
* PCIe topology exported by mvebu hw is quite complicated. In
* reality has something like N fully independent host bridges
* where each host bridge has one PCIe Root Port (which acts as
* PCI Bridge device). Each host bridge has its own independent
* internal registers, independent access to PCI config space,
* independent interrupt lines, independent window and memory
* access configuration. But additionally there is some kind of
* peer-to-peer support between PCIe devices behind different
* host bridges limited just to forwarding of memory and I/O
* transactions (forwarding of error messages and config cycles
* is not supported). So we could say there are N independent
* PCIe Root Complexes.
*
* For this kind of setup DT should have been structured into
* N independent PCIe controllers / host bridges. But instead
* structure in past was defined to put PCIe Root Ports of all
* host bridges into one bus zero, like in classic multi-port
* Root Complex setup with just one host bridge.
*
* This means that pci-mvebu.c driver provides "virtual" bus 0
* on which registers all PCIe Root Ports (PCI Bridge devices)
* specified in DT by their BDF addresses and virtually routes
* PCI config access of each PCI bridge device to specific PCIe
* host bridge.
*
* Normally PCI Bridge should choose between Type 0 and Type 1
* config requests based on primary and secondary bus numbers
* configured on the bridge itself. But because mvebu PCI Bridge
* does not have registers for primary and secondary bus numbers
* in its config space, it determinates type of config requests
* via its own custom way.
*
* There are two options how mvebu determinate type of config
* request.
*
* 1. If Secondary Bus Number Enable bit is not set or is not
* available (applies for pre-XP PCIe controllers) then Type 0
* is used if target bus number equals Local Bus Number (bits
* [15:8] in register 0x1a04) and target device number differs
* from Local Device Number (bits [20:16] in register 0x1a04).
* Type 1 is used if target bus number differs from Local Bus
* Number. And when target bus number equals Local Bus Number
* and target device equals Local Device Number then request is
* routed to Local PCI Bridge (PCIe Root Port).
*
* 2. If Secondary Bus Number Enable bit is set (bit 7 in
* register 0x1a2c) then mvebu hw determinate type of config
* request like compliant PCI Bridge based on primary bus number
* which is configured via Local Bus Number (bits [15:8] in
* register 0x1a04) and secondary bus number which is configured
* via Secondary Bus Number (bits [7:0] in register 0x1a2c).
* Local PCI Bridge (PCIe Root Port) is available on primary bus
* as device with Local Device Number (bits [20:16] in register
* 0x1a04).
*
* Secondary Bus Number Enable bit is disabled by default and
* option 2. is not available on pre-XP PCIe controllers. Hence
* this driver always use option 1.
*
* Basically it means that primary and secondary buses shares
* one virtual number configured via Local Bus Number bits and
* Local Device Number bits determinates if accessing primary
* or secondary bus. Set Local Device Number to 1 and redirect
* all writes of PCI Bridge Secondary Bus Number register to
* Local Bus Number (bits [15:8] in register 0x1a04).
*
* So when accessing devices on buses behind secondary bus
* number it would work correctly. And also when accessing
* device 0 at secondary bus number via config space would be
* correctly routed to secondary bus. Due to issues described
* in mvebu_pcie_setup_hw(), PCI Bridges at primary bus (zero)
* are not accessed directly via PCI config space but rarher
* indirectly via kernel emulated PCI bridge driver.
*/
mvebu_pcie_setup_hw(port);
mvebu_pcie_set_local_dev_nr(port, 1);
mvebu_pcie_set_local_bus_nr(port, 0);
}
pcie->nports = i;
bridge->sysdata = pcie;
bridge->ops = &mvebu_pcie_ops;
bridge->align_resource = mvebu_pcie_align_resource;
bridge->map_irq = mvebu_pcie_map_irq;
return pci_host_probe(bridge);
}
static int mvebu_pcie_remove(struct platform_device *pdev)
{
struct mvebu_pcie *pcie = platform_get_drvdata(pdev);
struct pci_host_bridge *bridge = pci_host_bridge_from_priv(pcie);
u32 cmd;
int i;
/* Remove PCI bus with all devices. */
pci_lock_rescan_remove();
pci_stop_root_bus(bridge->bus);
pci_remove_root_bus(bridge->bus);
pci_unlock_rescan_remove();
for (i = 0; i < pcie->nports; i++) {
struct mvebu_pcie_port *port = &pcie->ports[i];
if (!port->base)
continue;
/* Disable Root Bridge I/O space, memory space and bus mastering. */
cmd = mvebu_readl(port, PCIE_CMD_OFF);
cmd &= ~(PCI_COMMAND_IO | PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER);
mvebu_writel(port, cmd, PCIE_CMD_OFF);
/* Mask all interrupt sources. */
mvebu_writel(port, 0, PCIE_MASK_OFF);
/* Free config space for emulated root bridge. */
pci_bridge_emul_cleanup(&port->bridge);
/* Disable and clear BARs and windows. */
mvebu_pcie_disable_wins(port);
/* Delete PCIe IO and MEM windows. */
if (port->iowin.size)
mvebu_pcie_del_windows(port, port->iowin.base, port->iowin.size);
if (port->memwin.size)
mvebu_pcie_del_windows(port, port->memwin.base, port->memwin.size);
/* Power down card and disable clocks. Must be the last step. */
mvebu_pcie_powerdown(port);
}
return 0;
}
static const struct of_device_id mvebu_pcie_of_match_table[] = {
{ .compatible = "marvell,armada-xp-pcie", },
{ .compatible = "marvell,armada-370-pcie", },
{ .compatible = "marvell,dove-pcie", },
{ .compatible = "marvell,kirkwood-pcie", },
{},
};
static const struct dev_pm_ops mvebu_pcie_pm_ops = {
SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(mvebu_pcie_suspend, mvebu_pcie_resume)
};
static struct platform_driver mvebu_pcie_driver = {
.driver = {
.name = "mvebu-pcie",
.of_match_table = mvebu_pcie_of_match_table,
.pm = &mvebu_pcie_pm_ops,
},
.probe = mvebu_pcie_probe,
.remove = mvebu_pcie_remove,
};
module_platform_driver(mvebu_pcie_driver);
MODULE_AUTHOR("Thomas Petazzoni <thomas.petazzoni@bootlin.com>");
MODULE_AUTHOR("Pali Rohár <pali@kernel.org>");
MODULE_DESCRIPTION("Marvell EBU PCIe controller");
MODULE_LICENSE("GPL v2");
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