105 lines
2.6 KiB
C
105 lines
2.6 KiB
C
|
/*
|
||
|
|
* pci.c -- basic PCI support code
|
||
|
|
*
|
||
|
|
* 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.
|
||
|
|
*
|
||
|
|
* (C) Copyright 2011, Greg Ungerer <gerg@uclinux.org>
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include <linux/kernel.h>
|
||
|
|
#include <linux/types.h>
|
||
|
|
#include <linux/mm.h>
|
||
|
|
#include <linux/init.h>
|
||
|
|
#include <linux/pci.h>
|
||
|
|
|
||
|
|
/*
|
||
|
|
* From arch/i386/kernel/pci-i386.c:
|
||
|
|
*
|
||
|
|
* 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 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)
|
||
|
|
{
|
||
|
|
resource_size_t start = res->start;
|
||
|
|
|
||
|
|
if ((res->flags & IORESOURCE_IO) && (start & 0x300))
|
||
|
|
start = (start + 0x3ff) & ~0x3ff;
|
||
|
|
|
||
|
|
start = (start + align - 1) & ~(align - 1);
|
||
|
|
|
||
|
|
return start;
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* This is taken from the ARM code for this.
|
||
|
|
*/
|
||
|
|
int pcibios_enable_device(struct pci_dev *dev, int mask)
|
||
|
|
{
|
||
|
|
struct resource *r;
|
||
|
|
u16 cmd, newcmd;
|
||
|
|
int idx;
|
||
|
|
|
||
|
|
pci_read_config_word(dev, PCI_COMMAND, &cmd);
|
||
|
|
newcmd = cmd;
|
||
|
|
|
||
|
|
for (idx = 0; idx < 6; idx++) {
|
||
|
|
/* Only set up the requested stuff */
|
||
|
|
if (!(mask & (1 << idx)))
|
||
|
|
continue;
|
||
|
|
|
||
|
|
r = dev->resource + idx;
|
||
|
|
if (!r->start && r->end) {
|
||
|
|
pr_err("PCI: Device %s not available because of resource collisions\n",
|
||
|
|
pci_name(dev));
|
||
|
|
return -EINVAL;
|
||
|
|
}
|
||
|
|
if (r->flags & IORESOURCE_IO)
|
||
|
|
newcmd |= PCI_COMMAND_IO;
|
||
|
|
if (r->flags & IORESOURCE_MEM)
|
||
|
|
newcmd |= PCI_COMMAND_MEMORY;
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Bridges (eg, cardbus bridges) need to be fully enabled
|
||
|
|
*/
|
||
|
|
if ((dev->class >> 16) == PCI_BASE_CLASS_BRIDGE)
|
||
|
|
newcmd |= PCI_COMMAND_IO | PCI_COMMAND_MEMORY;
|
||
|
|
|
||
|
|
|
||
|
|
if (newcmd != cmd) {
|
||
|
|
pr_info("PCI: enabling device %s (0x%04x -> 0x%04x)\n",
|
||
|
|
pci_name(dev), cmd, newcmd);
|
||
|
|
pci_write_config_word(dev, PCI_COMMAND, newcmd);
|
||
|
|
}
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
void pcibios_fixup_bus(struct pci_bus *bus)
|
||
|
|
{
|
||
|
|
struct pci_dev *dev;
|
||
|
|
|
||
|
|
list_for_each_entry(dev, &bus->devices, bus_list) {
|
||
|
|
pci_write_config_byte(dev, PCI_CACHE_LINE_SIZE, 8);
|
||
|
|
pci_write_config_byte(dev, PCI_LATENCY_TIMER, 32);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
char *pcibios_setup(char *str)
|
||
|
|
{
|
||
|
|
return str;
|
||
|
|
}
|
||
|
|
|