xref: /openbmc/linux/arch/x86/pci/early.c (revision fb9aa6f1d4a1e11e66a680460b2c2b2b10b62f79)
1*fb9aa6f1SThomas Gleixner #include <linux/kernel.h>
2*fb9aa6f1SThomas Gleixner #include <linux/pci.h>
3*fb9aa6f1SThomas Gleixner #include <asm/pci-direct.h>
4*fb9aa6f1SThomas Gleixner #include <asm/io.h>
5*fb9aa6f1SThomas Gleixner #include "pci.h"
6*fb9aa6f1SThomas Gleixner 
7*fb9aa6f1SThomas Gleixner /* Direct PCI access. This is used for PCI accesses in early boot before
8*fb9aa6f1SThomas Gleixner    the PCI subsystem works. */
9*fb9aa6f1SThomas Gleixner 
10*fb9aa6f1SThomas Gleixner #define PDprintk(x...)
11*fb9aa6f1SThomas Gleixner 
12*fb9aa6f1SThomas Gleixner u32 read_pci_config(u8 bus, u8 slot, u8 func, u8 offset)
13*fb9aa6f1SThomas Gleixner {
14*fb9aa6f1SThomas Gleixner 	u32 v;
15*fb9aa6f1SThomas Gleixner 	outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8);
16*fb9aa6f1SThomas Gleixner 	v = inl(0xcfc);
17*fb9aa6f1SThomas Gleixner 	if (v != 0xffffffff)
18*fb9aa6f1SThomas Gleixner 		PDprintk("%x reading 4 from %x: %x\n", slot, offset, v);
19*fb9aa6f1SThomas Gleixner 	return v;
20*fb9aa6f1SThomas Gleixner }
21*fb9aa6f1SThomas Gleixner 
22*fb9aa6f1SThomas Gleixner u8 read_pci_config_byte(u8 bus, u8 slot, u8 func, u8 offset)
23*fb9aa6f1SThomas Gleixner {
24*fb9aa6f1SThomas Gleixner 	u8 v;
25*fb9aa6f1SThomas Gleixner 	outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8);
26*fb9aa6f1SThomas Gleixner 	v = inb(0xcfc + (offset&3));
27*fb9aa6f1SThomas Gleixner 	PDprintk("%x reading 1 from %x: %x\n", slot, offset, v);
28*fb9aa6f1SThomas Gleixner 	return v;
29*fb9aa6f1SThomas Gleixner }
30*fb9aa6f1SThomas Gleixner 
31*fb9aa6f1SThomas Gleixner u16 read_pci_config_16(u8 bus, u8 slot, u8 func, u8 offset)
32*fb9aa6f1SThomas Gleixner {
33*fb9aa6f1SThomas Gleixner 	u16 v;
34*fb9aa6f1SThomas Gleixner 	outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8);
35*fb9aa6f1SThomas Gleixner 	v = inw(0xcfc + (offset&2));
36*fb9aa6f1SThomas Gleixner 	PDprintk("%x reading 2 from %x: %x\n", slot, offset, v);
37*fb9aa6f1SThomas Gleixner 	return v;
38*fb9aa6f1SThomas Gleixner }
39*fb9aa6f1SThomas Gleixner 
40*fb9aa6f1SThomas Gleixner void write_pci_config(u8 bus, u8 slot, u8 func, u8 offset,
41*fb9aa6f1SThomas Gleixner 				    u32 val)
42*fb9aa6f1SThomas Gleixner {
43*fb9aa6f1SThomas Gleixner 	PDprintk("%x writing to %x: %x\n", slot, offset, val);
44*fb9aa6f1SThomas Gleixner 	outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8);
45*fb9aa6f1SThomas Gleixner 	outl(val, 0xcfc);
46*fb9aa6f1SThomas Gleixner }
47*fb9aa6f1SThomas Gleixner 
48*fb9aa6f1SThomas Gleixner void write_pci_config_byte(u8 bus, u8 slot, u8 func, u8 offset, u8 val)
49*fb9aa6f1SThomas Gleixner {
50*fb9aa6f1SThomas Gleixner 	PDprintk("%x writing to %x: %x\n", slot, offset, val);
51*fb9aa6f1SThomas Gleixner 	outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8);
52*fb9aa6f1SThomas Gleixner 	outb(val, 0xcfc);
53*fb9aa6f1SThomas Gleixner }
54*fb9aa6f1SThomas Gleixner 
55*fb9aa6f1SThomas Gleixner int early_pci_allowed(void)
56*fb9aa6f1SThomas Gleixner {
57*fb9aa6f1SThomas Gleixner 	return (pci_probe & (PCI_PROBE_CONF1|PCI_PROBE_NOEARLY)) ==
58*fb9aa6f1SThomas Gleixner 			PCI_PROBE_CONF1;
59*fb9aa6f1SThomas Gleixner }
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