kernel_optimize_test/arch/arm/mach-kirkwood/pcie.c
Eric Cooper 0e0cdd3770 [ARM] Kirkwood: enable PCIe before reading device ID register
PCIe may have been disabled (by kirkwood_clock_gate)
if this kernel was started by kexec.  Make sure PCIe
is enabled before attempting to access the device ID
register, otherwise the system will hang.

Signed-off-by: Eric Cooper <ecc@cmu.edu>
Signed-off-by: Nicolas Pitre <nico@fluxnic.net>
2011-03-03 16:26:56 -05:00

283 lines
6.5 KiB
C

/*
* arch/arm/mach-kirkwood/pcie.c
*
* PCIe functions for Marvell Kirkwood SoCs
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*/
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/slab.h>
#include <linux/mbus.h>
#include <asm/irq.h>
#include <asm/mach/pci.h>
#include <plat/pcie.h>
#include <mach/bridge-regs.h>
#include "common.h"
void kirkwood_enable_pcie(void)
{
u32 curr = readl(CLOCK_GATING_CTRL);
if (!(curr & CGC_PEX0))
writel(curr | CGC_PEX0, CLOCK_GATING_CTRL);
}
void __init kirkwood_pcie_id(u32 *dev, u32 *rev)
{
kirkwood_enable_pcie();
*dev = orion_pcie_dev_id((void __iomem *)PCIE_VIRT_BASE);
*rev = orion_pcie_rev((void __iomem *)PCIE_VIRT_BASE);
}
struct pcie_port {
u8 root_bus_nr;
void __iomem *base;
spinlock_t conf_lock;
int irq;
struct resource res[2];
};
static int pcie_port_map[2];
static int num_pcie_ports;
static inline struct pcie_port *bus_to_port(struct pci_bus *bus)
{
struct pci_sys_data *sys = bus->sysdata;
return sys->private_data;
}
static int pcie_valid_config(struct pcie_port *pp, int bus, int dev)
{
/*
* Don't go out when trying to access --
* 1. nonexisting device on local bus
* 2. where there's no device connected (no link)
*/
if (bus == pp->root_bus_nr && dev == 0)
return 1;
if (!orion_pcie_link_up(pp->base))
return 0;
if (bus == pp->root_bus_nr && dev != 1)
return 0;
return 1;
}
/*
* PCIe config cycles are done by programming the PCIE_CONF_ADDR register
* and then reading the PCIE_CONF_DATA register. Need to make sure these
* transactions are atomic.
*/
static int pcie_rd_conf(struct pci_bus *bus, u32 devfn, int where,
int size, u32 *val)
{
struct pcie_port *pp = bus_to_port(bus);
unsigned long flags;
int ret;
if (pcie_valid_config(pp, bus->number, PCI_SLOT(devfn)) == 0) {
*val = 0xffffffff;
return PCIBIOS_DEVICE_NOT_FOUND;
}
spin_lock_irqsave(&pp->conf_lock, flags);
ret = orion_pcie_rd_conf(pp->base, bus, devfn, where, size, val);
spin_unlock_irqrestore(&pp->conf_lock, flags);
return ret;
}
static int pcie_wr_conf(struct pci_bus *bus, u32 devfn,
int where, int size, u32 val)
{
struct pcie_port *pp = bus_to_port(bus);
unsigned long flags;
int ret;
if (pcie_valid_config(pp, bus->number, PCI_SLOT(devfn)) == 0)
return PCIBIOS_DEVICE_NOT_FOUND;
spin_lock_irqsave(&pp->conf_lock, flags);
ret = orion_pcie_wr_conf(pp->base, bus, devfn, where, size, val);
spin_unlock_irqrestore(&pp->conf_lock, flags);
return ret;
}
static struct pci_ops pcie_ops = {
.read = pcie_rd_conf,
.write = pcie_wr_conf,
};
static void __init pcie0_ioresources_init(struct pcie_port *pp)
{
pp->base = (void __iomem *)PCIE_VIRT_BASE;
pp->irq = IRQ_KIRKWOOD_PCIE;
/*
* IORESOURCE_IO
*/
pp->res[0].name = "PCIe 0 I/O Space";
pp->res[0].start = KIRKWOOD_PCIE_IO_BUS_BASE;
pp->res[0].end = pp->res[0].start + KIRKWOOD_PCIE_IO_SIZE - 1;
pp->res[0].flags = IORESOURCE_IO;
/*
* IORESOURCE_MEM
*/
pp->res[1].name = "PCIe 0 MEM";
pp->res[1].start = KIRKWOOD_PCIE_MEM_PHYS_BASE;
pp->res[1].end = pp->res[1].start + KIRKWOOD_PCIE_MEM_SIZE - 1;
pp->res[1].flags = IORESOURCE_MEM;
}
static void __init pcie1_ioresources_init(struct pcie_port *pp)
{
pp->base = (void __iomem *)PCIE1_VIRT_BASE;
pp->irq = IRQ_KIRKWOOD_PCIE1;
/*
* IORESOURCE_IO
*/
pp->res[0].name = "PCIe 1 I/O Space";
pp->res[0].start = KIRKWOOD_PCIE1_IO_BUS_BASE;
pp->res[0].end = pp->res[0].start + KIRKWOOD_PCIE1_IO_SIZE - 1;
pp->res[0].flags = IORESOURCE_IO;
/*
* IORESOURCE_MEM
*/
pp->res[1].name = "PCIe 1 MEM";
pp->res[1].start = KIRKWOOD_PCIE1_MEM_PHYS_BASE;
pp->res[1].end = pp->res[1].start + KIRKWOOD_PCIE1_MEM_SIZE - 1;
pp->res[1].flags = IORESOURCE_MEM;
}
static int __init kirkwood_pcie_setup(int nr, struct pci_sys_data *sys)
{
extern unsigned int kirkwood_clk_ctrl;
struct pcie_port *pp;
int index;
if (nr >= num_pcie_ports)
return 0;
index = pcie_port_map[nr];
printk(KERN_INFO "PCI: bus%d uses PCIe port %d\n", sys->busnr, index);
pp = kzalloc(sizeof(*pp), GFP_KERNEL);
if (!pp)
panic("PCIe: failed to allocate pcie_port data");
sys->private_data = pp;
pp->root_bus_nr = sys->busnr;
spin_lock_init(&pp->conf_lock);
switch (index) {
case 0:
kirkwood_clk_ctrl |= CGC_PEX0;
pcie0_ioresources_init(pp);
break;
case 1:
kirkwood_clk_ctrl |= CGC_PEX1;
pcie1_ioresources_init(pp);
break;
default:
panic("PCIe setup: invalid controller %d", index);
}
if (request_resource(&ioport_resource, &pp->res[0]))
panic("Request PCIe%d IO resource failed\n", index);
if (request_resource(&iomem_resource, &pp->res[1]))
panic("Request PCIe%d Memory resource failed\n", index);
sys->resource[0] = &pp->res[0];
sys->resource[1] = &pp->res[1];
sys->resource[2] = NULL;
sys->io_offset = 0;
/*
* Generic PCIe unit setup.
*/
orion_pcie_set_local_bus_nr(pp->base, sys->busnr);
orion_pcie_setup(pp->base, &kirkwood_mbus_dram_info);
return 1;
}
static void __devinit rc_pci_fixup(struct pci_dev *dev)
{
/*
* Prevent enumeration of root complex.
*/
if (dev->bus->parent == NULL && dev->devfn == 0) {
int i;
for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
dev->resource[i].start = 0;
dev->resource[i].end = 0;
dev->resource[i].flags = 0;
}
}
}
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_MARVELL, PCI_ANY_ID, rc_pci_fixup);
static struct pci_bus __init *
kirkwood_pcie_scan_bus(int nr, struct pci_sys_data *sys)
{
struct pci_bus *bus;
if (nr < num_pcie_ports) {
bus = pci_scan_bus(sys->busnr, &pcie_ops, sys);
} else {
bus = NULL;
BUG();
}
return bus;
}
static int __init kirkwood_pcie_map_irq(struct pci_dev *dev, u8 slot, u8 pin)
{
struct pcie_port *pp = bus_to_port(dev->bus);
return pp->irq;
}
static struct hw_pci kirkwood_pci __initdata = {
.swizzle = pci_std_swizzle,
.setup = kirkwood_pcie_setup,
.scan = kirkwood_pcie_scan_bus,
.map_irq = kirkwood_pcie_map_irq,
};
static void __init add_pcie_port(int index, unsigned long base)
{
printk(KERN_INFO "Kirkwood PCIe port %d: ", index);
if (orion_pcie_link_up((void __iomem *)base)) {
printk(KERN_INFO "link up\n");
pcie_port_map[num_pcie_ports++] = index;
} else
printk(KERN_INFO "link down, ignoring\n");
}
void __init kirkwood_pcie_init(unsigned int portmask)
{
if (portmask & KW_PCIE0)
add_pcie_port(0, PCIE_VIRT_BASE);
if (portmask & KW_PCIE1)
add_pcie_port(1, PCIE1_VIRT_BASE);
kirkwood_pci.nr_controllers = num_pcie_ports;
pci_common_init(&kirkwood_pci);
}