kernel-ark/include/asm-i386/ide.h
Alan Cox 25000c2c8a [PATCH] ide: explain the PCI bus test we do in <asm-i386/ide.h>
Matthew Wilcox asked that this got a comment explaining why it is done
so here it is.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
2005-11-10 00:10:37 +01:00

80 lines
1.5 KiB
C

/*
* linux/include/asm-i386/ide.h
*
* Copyright (C) 1994-1996 Linus Torvalds & authors
*/
/*
* This file contains the i386 architecture specific IDE code.
*/
#ifndef __ASMi386_IDE_H
#define __ASMi386_IDE_H
#ifdef __KERNEL__
#include <linux/config.h>
#ifndef MAX_HWIFS
# ifdef CONFIG_BLK_DEV_IDEPCI
#define MAX_HWIFS 10
# else
#define MAX_HWIFS 6
# endif
#endif
#define IDE_ARCH_OBSOLETE_DEFAULTS
static __inline__ int ide_default_irq(unsigned long base)
{
switch (base) {
case 0x1f0: return 14;
case 0x170: return 15;
case 0x1e8: return 11;
case 0x168: return 10;
case 0x1e0: return 8;
case 0x160: return 12;
default:
return 0;
}
}
static __inline__ unsigned long ide_default_io_base(int index)
{
/*
* If PCI is present then it is not safe to poke around
* the other legacy IDE ports. Only 0x1f0 and 0x170 are
* defined compatibility mode ports for PCI. A user can
* override this using ide= but we must default safe.
*/
if (pci_find_device(PCI_ANY_ID, PCI_ANY_ID, NULL) == NULL) {
switch(index) {
case 2: return 0x1e8;
case 3: return 0x168;
case 4: return 0x1e0;
case 5: return 0x160;
}
}
switch (index) {
case 0: return 0x1f0;
case 1: return 0x170;
default:
return 0;
}
}
#define IDE_ARCH_OBSOLETE_INIT
#define ide_default_io_ctl(base) ((base) + 0x206) /* obsolete */
#ifdef CONFIG_BLK_DEV_IDEPCI
#define ide_init_default_irq(base) (0)
#else
#define ide_init_default_irq(base) ide_default_irq(base)
#endif
#include <asm-generic/ide_iops.h>
#endif /* __KERNEL__ */
#endif /* __ASMi386_IDE_H */