Revision 4dc2287c1805e7fe8a7cb90bbcd44abee8cdb914 authored by Bjorn Helgaas on 16 December 2010, 17:38:56 UTC, committed by Jesse Barnes on 17 December 2010, 18:01:24 UTC
When we allocate address space, e.g., to assign it to a PCI device, don't
allocate anything mentioned in the BIOS E820 memory map.
On recent machines (2008 and newer), we assign PCI resources from the
windows described by the ACPI PCI host bridge _CRS. On many Dell
machines, these windows overlap some E820 reserved areas, e.g.,
BIOS-e820: 00000000bfe4dc00 - 00000000c0000000 (reserved)
pci_root PNP0A03:00: host bridge window [mem 0xbff00000-0xdfffffff]
If we put devices at 0xbff00000, they don't work, probably because
that's really RAM, not I/O memory. This patch prevents that by removing
the 0xbfe4dc00-0xbfffffff area from the "available" resource.
I'm not very happy with this solution because Windows solves the problem
differently (it seems to ignore E820 reserved areas and it allocates
top-down instead of bottom-up; details at comment 45 of the bugzilla
below). That means we're vulnerable to BIOS defects that Windows would not
trip over. For example, if BIOS described a device in ACPI but didn't
mention it in E820, Windows would work fine but Linux would fail.
Reference: https://bugzilla.kernel.org/show_bug.cgi?id=16228
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
1 parent 30919b0
wext.h
#ifndef __NET_WEXT_H
#define __NET_WEXT_H
#include <net/iw_handler.h>
struct net;
#ifdef CONFIG_WEXT_CORE
extern int wext_handle_ioctl(struct net *net, struct ifreq *ifr, unsigned int cmd,
void __user *arg);
extern int compat_wext_handle_ioctl(struct net *net, unsigned int cmd,
unsigned long arg);
extern struct iw_statistics *get_wireless_stats(struct net_device *dev);
extern int call_commit_handler(struct net_device *dev);
#else
static inline int wext_handle_ioctl(struct net *net, struct ifreq *ifr, unsigned int cmd,
void __user *arg)
{
return -EINVAL;
}
static inline int compat_wext_handle_ioctl(struct net *net, unsigned int cmd,
unsigned long arg)
{
return -EINVAL;
}
#endif
#ifdef CONFIG_WEXT_PROC
extern int wext_proc_init(struct net *net);
extern void wext_proc_exit(struct net *net);
#else
static inline int wext_proc_init(struct net *net)
{
return 0;
}
static inline void wext_proc_exit(struct net *net)
{
return;
}
#endif
#ifdef CONFIG_WEXT_PRIV
int ioctl_private_call(struct net_device *dev, struct iwreq *iwr,
unsigned int cmd, struct iw_request_info *info,
iw_handler handler);
int compat_private_call(struct net_device *dev, struct iwreq *iwr,
unsigned int cmd, struct iw_request_info *info,
iw_handler handler);
int iw_handler_get_private(struct net_device * dev,
struct iw_request_info * info,
union iwreq_data * wrqu,
char * extra);
#else
#define ioctl_private_call NULL
#define compat_private_call NULL
#endif
#endif /* __NET_WEXT_H */
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