linux/arch/x86/pci/early.c

60 lines
1.4 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include <linux/kernel.h>
#include <linux/pci.h>
#include <asm/pci-direct.h>
#include <asm/io.h>
#include <asm/pci_x86.h>
/* Direct PCI access. This is used for PCI accesses in early boot before
the PCI subsystem works. */
u32 read_pci_config(u8 bus, u8 slot, u8 func, u8 offset)
{
u32 v;
outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8);
v = inl(0xcfc);
return v;
}
u8 read_pci_config_byte(u8 bus, u8 slot, u8 func, u8 offset)
{
u8 v;
outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8);
v = inb(0xcfc + (offset&3));
return v;
}
u16 read_pci_config_16(u8 bus, u8 slot, u8 func, u8 offset)
{
u16 v;
outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8);
v = inw(0xcfc + (offset&2));
return v;
}
void write_pci_config(u8 bus, u8 slot, u8 func, u8 offset,
u32 val)
{
outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8);
outl(val, 0xcfc);
}
void write_pci_config_byte(u8 bus, u8 slot, u8 func, u8 offset, u8 val)
{
outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8);
outb(val, 0xcfc + (offset&3));
}
void write_pci_config_16(u8 bus, u8 slot, u8 func, u8 offset, u16 val)
{
outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8);
outw(val, 0xcfc + (offset&2));
}
int early_pci_allowed(void)
{
return (pci_probe & (PCI_PROBE_CONF1|PCI_PROBE_NOEARLY)) ==
PCI_PROBE_CONF1;
}