blob: 21f13e9aabe1b5f660cdb54b5d077f31c08c8e34 [file] [log] [blame]
/*
* arch/xtensa/kernel/pci.c
*
* PCI bios-type initialisation for PCI machines
*
* 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) 2001-2005 Tensilica Inc.
*
* Based largely on work from Cort (ppc/kernel/pci.c)
* IO functions copied from sparc.
*
* Chris Zankel <chris@zankel.net>
*
*/
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/delay.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/bootmem.h>
#include <asm/pci-bridge.h>
#include <asm/platform.h>
/* PCI Controller */
/*
* pcibios_alloc_controller
* pcibios_enable_device
* pcibios_fixups
* pcibios_align_resource
* pcibios_fixup_bus
* pci_bus_add_device
*/
static struct pci_controller *pci_ctrl_head;
static struct pci_controller **pci_ctrl_tail = &pci_ctrl_head;
static int pci_bus_count;
/*
* 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..
*/
resource_size_t
pcibios_align_resource(void *data, const struct resource *res,
resource_size_t size, resource_size_t align)
{
struct pci_dev *dev = data;
resource_size_t start = res->start;
if (res->flags & IORESOURCE_IO) {
if (size > 0x100) {
pr_err("PCI: I/O Region %s/%d too large (%u bytes)\n",
pci_name(dev), dev->resource - res,
size);
}
if (start & 0x300)
start = (start + 0x3ff) & ~0x3ff;
}
return start;
}
static void __init pci_controller_apertures(struct pci_controller *pci_ctrl,
struct list_head *resources)
{
struct resource *res;
unsigned long io_offset;
int i;
io_offset = (unsigned long)pci_ctrl->io_space.base;
res = &pci_ctrl->io_resource;
if (!res->flags) {
if (io_offset)
pr_err("I/O resource not set for host bridge %d\n",
pci_ctrl->index);
res->start = 0;
res->end = IO_SPACE_LIMIT;
res->flags = IORESOURCE_IO;
}
res->start += io_offset;
res->end += io_offset;
pci_add_resource_offset(resources, res, io_offset);
for (i = 0; i < 3; i++) {
res = &pci_ctrl->mem_resources[i];
if (!res->flags) {
if (i > 0)
continue;
pr_err("Memory resource not set for host bridge %d\n",
pci_ctrl->index);
res->start = 0;
res->end = ~0U;
res->flags = IORESOURCE_MEM;
}
pci_add_resource(resources, res);
}
}
static int __init pcibios_init(void)
{
struct pci_controller *pci_ctrl;
struct list_head resources;
struct pci_bus *bus;
int next_busno = 0, ret;
pr_info("PCI: Probing PCI hardware\n");
/* Scan all of the recorded PCI controllers. */
for (pci_ctrl = pci_ctrl_head; pci_ctrl; pci_ctrl = pci_ctrl->next) {
pci_ctrl->last_busno = 0xff;
INIT_LIST_HEAD(&resources);
pci_controller_apertures(pci_ctrl, &resources);
bus = pci_scan_root_bus(NULL, pci_ctrl->first_busno,
pci_ctrl->ops, pci_ctrl, &resources);
if (!bus)
continue;
pci_ctrl->bus = bus;
pci_ctrl->last_busno = bus->busn_res.end;
if (next_busno <= pci_ctrl->last_busno)
next_busno = pci_ctrl->last_busno+1;
}
pci_bus_count = next_busno;
ret = platform_pcibios_fixup();
if (ret)
return ret;
for (pci_ctrl = pci_ctrl_head; pci_ctrl; pci_ctrl = pci_ctrl->next) {
if (pci_ctrl->bus)
pci_bus_add_devices(pci_ctrl->bus);
}
return 0;
}
subsys_initcall(pcibios_init);
void pcibios_fixup_bus(struct pci_bus *bus)
{
if (bus->parent) {
/* This is a subordinate bridge */
pci_read_bridge_bases(bus);
}
}
void pcibios_set_master(struct pci_dev *dev)
{
/* No special bus mastering setup handling */
}
int pcibios_enable_device(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<6; idx++) {
r = &dev->resource[idx];
if (!r->start && r->end) {
pci_err(dev, "can't enable device: resource collisions\n");
return -EINVAL;
}
if (r->flags & IORESOURCE_IO)
cmd |= PCI_COMMAND_IO;
if (r->flags & IORESOURCE_MEM)
cmd |= PCI_COMMAND_MEMORY;
}
if (cmd != old_cmd) {
pci_info(dev, "enabling device (%04x -> %04x)\n", old_cmd, cmd);
pci_write_config_word(dev, PCI_COMMAND, cmd);
}
return 0;
}
/*
* Platform support for /proc/bus/pci/X/Y mmap()s.
* -- paulus.
*/
int pci_iobar_pfn(struct pci_dev *pdev, int bar, struct vm_area_struct *vma)
{
struct pci_controller *pci_ctrl = (struct pci_controller*) pdev->sysdata;
resource_size_t ioaddr = pci_resource_start(pdev, bar);
if (pci_ctrl == 0)
return -EINVAL; /* should never happen */
/* Convert to an offset within this PCI controller */
ioaddr -= (unsigned long)pci_ctrl->io_space.base;
vma->vm_pgoff += (ioaddr + pci_ctrl->io_space.start) >> PAGE_SHIFT;
return 0;
}