linux/arch/x86/pci/broadcom_bus.c
Bjorn Helgaas 30e664afb5 x86/PCI: don't use native Broadcom CNB20LE driver when ACPI is available
The broadcom_bus.c quirk was written (without benefit of documentation)
to support PCI hotplug on an old system that doesn't have ACPI.  As
such, we should only use it when the system doesn't have ACPI.

If the system does have ACPI and we need the host bridge description, we
should get it from the ACPI _CRS method.  On machines older than 2008,
we currently ignore _CRS, but that doesn't mean we should use
broadcom_bus.c.  It means we should either (a) do what we've done in the
past and assume everything in the PCI gap is routed to bus 0 (so hotplug
may not work), or (b) arrange to use _CRS.  This patch does (a).

Reference: https://bugzilla.redhat.com/show_bug.cgi?id=665109
Acked-by: Ira W. Snyder <iws@ovro.caltech.edu>
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2011-01-14 08:55:41 -08:00

104 lines
2.8 KiB
C

/*
* Read address ranges from a Broadcom CNB20LE Host Bridge
*
* Copyright (c) 2010 Ira W. Snyder <iws@ovro.caltech.edu>
*
* 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.
*/
#include <linux/acpi.h>
#include <linux/delay.h>
#include <linux/dmi.h>
#include <linux/pci.h>
#include <linux/init.h>
#include <asm/pci_x86.h>
#include "bus_numa.h"
static void __devinit cnb20le_res(struct pci_dev *dev)
{
struct pci_root_info *info;
struct resource res;
u16 word1, word2;
u8 fbus, lbus;
int i;
#ifdef CONFIG_ACPI
/*
* We should get host bridge information from ACPI unless the BIOS
* doesn't support it.
*/
if (acpi_os_get_root_pointer())
return;
#endif
info = &pci_root_info[pci_root_num];
pci_root_num++;
/* read the PCI bus numbers */
pci_read_config_byte(dev, 0x44, &fbus);
pci_read_config_byte(dev, 0x45, &lbus);
info->bus_min = fbus;
info->bus_max = lbus;
/*
* Add the legacy IDE ports on bus 0
*
* These do not exist anywhere in the bridge registers, AFAICT. I do
* not have the datasheet, so this is the best I can do.
*/
if (fbus == 0) {
update_res(info, 0x01f0, 0x01f7, IORESOURCE_IO, 0);
update_res(info, 0x03f6, 0x03f6, IORESOURCE_IO, 0);
update_res(info, 0x0170, 0x0177, IORESOURCE_IO, 0);
update_res(info, 0x0376, 0x0376, IORESOURCE_IO, 0);
update_res(info, 0xffa0, 0xffaf, IORESOURCE_IO, 0);
}
/* read the non-prefetchable memory window */
pci_read_config_word(dev, 0xc0, &word1);
pci_read_config_word(dev, 0xc2, &word2);
if (word1 != word2) {
res.start = (word1 << 16) | 0x0000;
res.end = (word2 << 16) | 0xffff;
res.flags = IORESOURCE_MEM;
update_res(info, res.start, res.end, res.flags, 0);
}
/* read the prefetchable memory window */
pci_read_config_word(dev, 0xc4, &word1);
pci_read_config_word(dev, 0xc6, &word2);
if (word1 != word2) {
res.start = (word1 << 16) | 0x0000;
res.end = (word2 << 16) | 0xffff;
res.flags = IORESOURCE_MEM | IORESOURCE_PREFETCH;
update_res(info, res.start, res.end, res.flags, 0);
}
/* read the IO port window */
pci_read_config_word(dev, 0xd0, &word1);
pci_read_config_word(dev, 0xd2, &word2);
if (word1 != word2) {
res.start = word1;
res.end = word2;
res.flags = IORESOURCE_IO;
update_res(info, res.start, res.end, res.flags, 0);
}
/* print information about this host bridge */
res.start = fbus;
res.end = lbus;
res.flags = IORESOURCE_BUS;
dev_info(&dev->dev, "CNB20LE PCI Host Bridge (domain %04x %pR)\n",
pci_domain_nr(dev->bus), &res);
for (i = 0; i < info->res_num; i++)
dev_info(&dev->dev, "host bridge window %pR\n", &info->res[i]);
}
DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_SERVERWORKS, PCI_DEVICE_ID_SERVERWORKS_LE,
cnb20le_res);