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linux-sg2042/arch/mips/pci/pci.c

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/*
* 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.
*
* Copyright (C) 2003, 04 Ralf Baechle (ralf@linux-mips.org)
*/
#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/bootmem.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/pci.h>
/*
* Indicate whether we respect the PCI setup left by the firmware.
*
* Make this long-lived so that we know when shutting down
* whether we probed only or not.
*/
int pci_probe_only;
#define PCI_ASSIGN_ALL_BUSSES 1
unsigned int pci_probe = PCI_ASSIGN_ALL_BUSSES;
/*
* The PCI controller list.
*/
struct pci_controller *hose_head, **hose_tail = &hose_head;
struct pci_controller *pci_isa_hose;
unsigned long PCIBIOS_MIN_IO = 0x0000;
unsigned long PCIBIOS_MIN_MEM = 0;
/*
* We need to avoid collisions with `mirrored' VGA ports
* and other strange ISA hardware, so we always want the
* addresses to be allocated in the 0x000-0x0ff region
* modulo 0x400.
*
* Why? Because some silly external IO cards only decode
* the low 10 bits of the IO address. The 0x00-0xff region
* is reserved for motherboard devices that decode all 16
* bits, so it's ok to allocate at, say, 0x2800-0x28ff,
* but we want to try to avoid allocating at 0x2900-0x2bff
* which might have be mirrored at 0x0100-0x03ff..
*/
void
pcibios_align_resource(void *data, struct resource *res,
unsigned long size, unsigned long align)
{
struct pci_dev *dev = data;
struct pci_controller *hose = dev->sysdata;
unsigned long start = res->start;
if (res->flags & IORESOURCE_IO) {
/* Make sure we start at our min on all hoses */
if (start < PCIBIOS_MIN_IO + hose->io_resource->start)
start = PCIBIOS_MIN_IO + hose->io_resource->start;
/*
* Put everything into 0x00-0xff region modulo 0x400
*/
if (start & 0x300)
start = (start + 0x3ff) & ~0x3ff;
} else if (res->flags & IORESOURCE_MEM) {
/* Make sure we start at our min on all hoses */
if (start < PCIBIOS_MIN_MEM + hose->mem_resource->start)
start = PCIBIOS_MIN_MEM + hose->mem_resource->start;
}
res->start = start;
}
void __init register_pci_controller(struct pci_controller *hose)
{
*hose_tail = hose;
hose_tail = &hose->next;
}
/* Most MIPS systems have straight-forward swizzling needs. */
static inline u8 bridge_swizzle(u8 pin, u8 slot)
{
return (((pin - 1) + slot) % 4) + 1;
}
static u8 __init common_swizzle(struct pci_dev *dev, u8 *pinp)
{
u8 pin = *pinp;
while (dev->bus->parent) {
pin = bridge_swizzle(pin, PCI_SLOT(dev->devfn));
/* Move up the chain of bridges. */
dev = dev->bus->self;
}
*pinp = pin;
/* The slot is the slot of the last bridge. */
return PCI_SLOT(dev->devfn);
}
static int __init pcibios_init(void)
{
struct pci_controller *hose;
struct pci_bus *bus;
int next_busno;
int need_domain_info = 0;
/* Scan all of the recorded PCI controllers. */
for (next_busno = 0, hose = hose_head; hose; hose = hose->next) {
if (request_resource(&iomem_resource, hose->mem_resource) < 0)
goto out;
if (request_resource(&ioport_resource, hose->io_resource) < 0)
goto out_free_mem_resource;
if (!hose->iommu)
PCI_DMA_BUS_IS_PHYS = 1;
if (hose->get_busno && pci_probe_only)
next_busno = (*hose->get_busno)();
bus = pci_scan_bus(next_busno, hose->pci_ops, hose);
hose->bus = bus;
hose->need_domain_info = need_domain_info;
if (bus) {
next_busno = bus->subordinate + 1;
/* Don't allow 8-bit bus number overflow inside the hose -
reserve some space for bridges. */
if (next_busno > 224) {
next_busno = 0;
need_domain_info = 1;
}
}
continue;
out_free_mem_resource:
release_resource(hose->mem_resource);
out:
printk(KERN_WARNING
"Skipping PCI bus scan due to resource conflict\n");
}
if (!pci_probe_only)
pci_assign_unassigned_resources();
pci_fixup_irqs(common_swizzle, pcibios_map_irq);
return 0;
}
subsys_initcall(pcibios_init);
static int pcibios_enable_resources(struct pci_dev *dev, int mask)
{
u16 cmd, old_cmd;
int idx;
struct resource *r;
pci_read_config_word(dev, PCI_COMMAND, &cmd);
old_cmd = cmd;
for (idx=0; idx < PCI_NUM_RESOURCES; idx++) {
/* Only set up the requested stuff */
if (!(mask & (1<<idx)))
continue;
r = &dev->resource[idx];
if (!r->start && r->end) {
printk(KERN_ERR "PCI: Device %s not available because of resource collisions\n", pci_name(dev));
return -EINVAL;
}
if (r->flags & IORESOURCE_IO)
cmd |= PCI_COMMAND_IO;
if (r->flags & IORESOURCE_MEM)
cmd |= PCI_COMMAND_MEMORY;
}
if (dev->resource[PCI_ROM_RESOURCE].start)
cmd |= PCI_COMMAND_MEMORY;
if (cmd != old_cmd) {
printk("PCI: Enabling device %s (%04x -> %04x)\n", pci_name(dev), old_cmd, cmd);
pci_write_config_word(dev, PCI_COMMAND, cmd);
}
return 0;
}
/*
* If we set up a device for bus mastering, we need to check the latency
* timer as certain crappy BIOSes forget to set it properly.
*/
unsigned int pcibios_max_latency = 255;
void pcibios_set_master(struct pci_dev *dev)
{
u8 lat;
pci_read_config_byte(dev, PCI_LATENCY_TIMER, &lat);
if (lat < 16)
lat = (64 <= pcibios_max_latency) ? 64 : pcibios_max_latency;
else if (lat > pcibios_max_latency)
lat = pcibios_max_latency;
else
return;
printk(KERN_DEBUG "PCI: Setting latency timer of device %s to %d\n",
pci_name(dev), lat);
pci_write_config_byte(dev, PCI_LATENCY_TIMER, lat);
}
unsigned int pcibios_assign_all_busses(void)
{
return (pci_probe & PCI_ASSIGN_ALL_BUSSES) ? 1 : 0;
}
int pcibios_enable_device(struct pci_dev *dev, int mask)
{
int err;
if ((err = pcibios_enable_resources(dev, mask)) < 0)
return err;
return pcibios_plat_dev_init(dev);
}
static void __init pcibios_fixup_device_resources(struct pci_dev *dev,
struct pci_bus *bus)
{
/* Update device resources. */
struct pci_controller *hose = (struct pci_controller *)bus->sysdata;
unsigned long offset = 0;
int i;
for (i = 0; i < PCI_NUM_RESOURCES; i++) {
if (!dev->resource[i].start)
continue;
if (dev->resource[i].flags & IORESOURCE_IO)
offset = hose->io_offset;
else if (dev->resource[i].flags & IORESOURCE_MEM)
offset = hose->mem_offset;
dev->resource[i].start += offset;
dev->resource[i].end += offset;
}
}
void __devinit pcibios_fixup_bus(struct pci_bus *bus)
{
/* Propagate hose info into the subordinate devices. */
struct pci_controller *hose = bus->sysdata;
struct list_head *ln;
struct pci_dev *dev = bus->self;
if (!dev) {
bus->resource[0] = hose->io_resource;
bus->resource[1] = hose->mem_resource;
} else if (pci_probe_only &&
(dev->class >> 8) == PCI_CLASS_BRIDGE_PCI) {
pci_read_bridge_bases(bus);
pcibios_fixup_device_resources(dev, bus);
}
for (ln = bus->devices.next; ln != &bus->devices; ln = ln->next) {
struct pci_dev *dev = pci_dev_b(ln);
if ((dev->class >> 8) != PCI_CLASS_BRIDGE_PCI)
pcibios_fixup_device_resources(dev, bus);
}
}
void __init
pcibios_update_irq(struct pci_dev *dev, int irq)
{
pci_write_config_byte(dev, PCI_INTERRUPT_LINE, irq);
}
void __devinit
pcibios_resource_to_bus(struct pci_dev *dev, struct pci_bus_region *region,
struct resource *res)
{
struct pci_controller *hose = (struct pci_controller *)dev->sysdata;
unsigned long offset = 0;
if (res->flags & IORESOURCE_IO)
offset = hose->io_offset;
else if (res->flags & IORESOURCE_MEM)
offset = hose->mem_offset;
region->start = res->start - offset;
region->end = res->end - offset;
}
void __devinit
pcibios_bus_to_resource(struct pci_dev *dev, struct resource *res,
struct pci_bus_region *region)
{
struct pci_controller *hose = (struct pci_controller *)dev->sysdata;
unsigned long offset = 0;
if (res->flags & IORESOURCE_IO)
offset = hose->io_offset;
else if (res->flags & IORESOURCE_MEM)
offset = hose->mem_offset;
res->start = region->start + offset;
res->end = region->end + offset;
}
#ifdef CONFIG_HOTPLUG
EXPORT_SYMBOL(pcibios_resource_to_bus);
EXPORT_SYMBOL(pcibios_bus_to_resource);
EXPORT_SYMBOL(PCIBIOS_MIN_IO);
EXPORT_SYMBOL(PCIBIOS_MIN_MEM);
#endif
char *pcibios_setup(char *str)
{
return str;
}
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