linux/arch/frv/mb93090-mb00/pci-frv.h
Greg Kroah-Hartman 1ba6ab11d8 PCI: remove initial bios sort of PCI devices on x86
We currently keep 2 lists of PCI devices in the system, one in the
driver core, and one all on its own.  This second list is sorted at boot
time, in "BIOS" order, to try to remain compatible with older kernels
(2.2 and earlier days).  There was also a "nosort" option to turn this
sorting off, to remain compatible with even older kernel versions, but
that just ends up being what we have been doing from 2.5 days...

Unfortunately, the second list of devices is not really ever used to 
determine the probing order of PCI devices or drivers[1].  That is done
using the driver core list instead.  This change happened back in the
early 2.5 days.

Relying on BIOS ording for the binding of drivers to specific device
names is problematic for many reasons, and userspace tools like udev
exist to properly name devices in a persistant manner if that is needed,
no reliance on the BIOS is needed.

Matt Domsch and others at Dell noticed this back in 2006, and added a
boot option to sort the PCI device lists (both of them) in a
breadth-first manner to help remain compatible with the 2.4 order, if
needed for any reason.  This option is not going away, as some systems
rely on them.

This patch removes the sorting of the internal PCI device list in "BIOS"
mode, as it's not needed at all anymore, and hasn't for many years.
I've also removed the PCI flags for this from some other arches that for
some reason defined them, but never used them.

This should not change the ordering of any drivers or device probing.

[1] The old-style pci_get_device and pci_find_device() still used this
sorting order, but there are very few drivers that use these functions,
as they are deprecated for use in this manner.  If for some reason, a
driver rely on the order and uses these functions, the breadth-first
boot option will resolve any problem.

Cc: Matt Domsch <Matt_Domsch@dell.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-04-20 21:46:58 -07:00

45 lines
955 B
C

/*
* Low-Level PCI Access for FRV machines.
*
* (c) 1999 Martin Mares <mj@ucw.cz>
*/
#include <asm/sections.h>
#undef DEBUG
#ifdef DEBUG
#define DBG(x...) printk(x)
#else
#define DBG(x...)
#endif
#define PCI_PROBE_BIOS 0x0001
#define PCI_PROBE_CONF1 0x0002
#define PCI_PROBE_CONF2 0x0004
#define PCI_NO_CHECKS 0x0400
#define PCI_ASSIGN_ROMS 0x1000
#define PCI_BIOS_IRQ_SCAN 0x2000
#define PCI_ASSIGN_ALL_BUSSES 0x4000
extern unsigned int __nongpreldata pci_probe;
/* pci-frv.c */
extern unsigned int pcibios_max_latency;
void pcibios_resource_survey(void);
int pcibios_enable_resources(struct pci_dev *, int);
/* pci-vdk.c */
extern int __nongpreldata pcibios_last_bus;
extern struct pci_bus *__nongpreldata pci_root_bus;
extern struct pci_ops *__nongpreldata pci_root_ops;
/* pci-irq.c */
extern unsigned int pcibios_irq_mask;
void pcibios_irq_init(void);
void pcibios_fixup_irqs(void);
void pcibios_enable_irq(struct pci_dev *dev);