xref: /openbmc/linux/arch/x86/pci/early.c (revision 8fa5723aa7e053d498336b48448b292fc2e0458b)
1 #include <linux/kernel.h>
2 #include <linux/pci.h>
3 #include <asm/pci-direct.h>
4 #include <asm/io.h>
5 #include "pci.h"
6 
7 /* Direct PCI access. This is used for PCI accesses in early boot before
8    the PCI subsystem works. */
9 
10 u32 read_pci_config(u8 bus, u8 slot, u8 func, u8 offset)
11 {
12 	u32 v;
13 	outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8);
14 	v = inl(0xcfc);
15 	if (v != 0xffffffff)
16 		pr_debug("%x reading 4 from %x: %x\n", slot, offset, v);
17 	return v;
18 }
19 
20 u8 read_pci_config_byte(u8 bus, u8 slot, u8 func, u8 offset)
21 {
22 	u8 v;
23 	outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8);
24 	v = inb(0xcfc + (offset&3));
25 	pr_debug("%x reading 1 from %x: %x\n", slot, offset, v);
26 	return v;
27 }
28 
29 u16 read_pci_config_16(u8 bus, u8 slot, u8 func, u8 offset)
30 {
31 	u16 v;
32 	outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8);
33 	v = inw(0xcfc + (offset&2));
34 	pr_debug("%x reading 2 from %x: %x\n", slot, offset, v);
35 	return v;
36 }
37 
38 void write_pci_config(u8 bus, u8 slot, u8 func, u8 offset,
39 				    u32 val)
40 {
41 	pr_debug("%x writing to %x: %x\n", slot, offset, val);
42 	outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8);
43 	outl(val, 0xcfc);
44 }
45 
46 void write_pci_config_byte(u8 bus, u8 slot, u8 func, u8 offset, u8 val)
47 {
48 	pr_debug("%x writing to %x: %x\n", slot, offset, val);
49 	outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8);
50 	outb(val, 0xcfc + (offset&3));
51 }
52 
53 void write_pci_config_16(u8 bus, u8 slot, u8 func, u8 offset, u16 val)
54 {
55 	pr_debug("%x writing to %x: %x\n", slot, offset, val);
56 	outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8);
57 	outw(val, 0xcfc + (offset&2));
58 }
59 
60 int early_pci_allowed(void)
61 {
62 	return (pci_probe & (PCI_PROBE_CONF1|PCI_PROBE_NOEARLY)) ==
63 			PCI_PROBE_CONF1;
64 }
65 
66 void early_dump_pci_device(u8 bus, u8 slot, u8 func)
67 {
68 	int i;
69 	int j;
70 	u32 val;
71 
72 	printk(KERN_INFO "PCI: %02x:%02x:%02x", bus, slot, func);
73 
74 	for (i = 0; i < 256; i += 4) {
75 		if (!(i & 0x0f))
76 			printk("\n%04x:",i);
77 
78 		val = read_pci_config(bus, slot, func, i);
79 		for (j = 0; j < 4; j++) {
80 			printk(" %02x", val & 0xff);
81 			val >>= 8;
82 		}
83 	}
84 	printk("\n");
85 }
86 
87 void early_dump_pci_devices(void)
88 {
89 	unsigned bus, slot, func;
90 
91 	if (!early_pci_allowed())
92 		return;
93 
94 	for (bus = 0; bus < 256; bus++) {
95 		for (slot = 0; slot < 32; slot++) {
96 			for (func = 0; func < 8; func++) {
97 				u32 class;
98 				u8 type;
99 				class = read_pci_config(bus, slot, func,
100 							PCI_CLASS_REVISION);
101 				if (class == 0xffffffff)
102 					break;
103 
104 				early_dump_pci_device(bus, slot, func);
105 
106 				/* No multi-function device? */
107 				type = read_pci_config_byte(bus, slot, func,
108 							       PCI_HEADER_TYPE);
109 				if (!(type & 0x80))
110 					break;
111 			}
112 		}
113 	}
114 }
115 
116