xref: /openbmc/linux/arch/x86/pci/early.c (revision bc5aa3a0)
1 #include <linux/kernel.h>
2 #include <linux/pci.h>
3 #include <asm/pci-direct.h>
4 #include <asm/io.h>
5 #include <asm/pci_x86.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 	return v;
16 }
17 
18 u8 read_pci_config_byte(u8 bus, u8 slot, u8 func, u8 offset)
19 {
20 	u8 v;
21 	outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8);
22 	v = inb(0xcfc + (offset&3));
23 	return v;
24 }
25 
26 u16 read_pci_config_16(u8 bus, u8 slot, u8 func, u8 offset)
27 {
28 	u16 v;
29 	outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8);
30 	v = inw(0xcfc + (offset&2));
31 	return v;
32 }
33 
34 void write_pci_config(u8 bus, u8 slot, u8 func, u8 offset,
35 				    u32 val)
36 {
37 	outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8);
38 	outl(val, 0xcfc);
39 }
40 
41 void write_pci_config_byte(u8 bus, u8 slot, u8 func, u8 offset, u8 val)
42 {
43 	outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8);
44 	outb(val, 0xcfc + (offset&3));
45 }
46 
47 void write_pci_config_16(u8 bus, u8 slot, u8 func, u8 offset, u16 val)
48 {
49 	outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8);
50 	outw(val, 0xcfc + (offset&2));
51 }
52 
53 int early_pci_allowed(void)
54 {
55 	return (pci_probe & (PCI_PROBE_CONF1|PCI_PROBE_NOEARLY)) ==
56 			PCI_PROBE_CONF1;
57 }
58 
59 void early_dump_pci_device(u8 bus, u8 slot, u8 func)
60 {
61 	int i;
62 	int j;
63 	u32 val;
64 
65 	printk(KERN_INFO "pci 0000:%02x:%02x.%d config space:",
66 	       bus, slot, func);
67 
68 	for (i = 0; i < 256; i += 4) {
69 		if (!(i & 0x0f))
70 			printk("\n  %02x:",i);
71 
72 		val = read_pci_config(bus, slot, func, i);
73 		for (j = 0; j < 4; j++) {
74 			printk(" %02x", val & 0xff);
75 			val >>= 8;
76 		}
77 	}
78 	printk("\n");
79 }
80 
81 void early_dump_pci_devices(void)
82 {
83 	unsigned bus, slot, func;
84 
85 	if (!early_pci_allowed())
86 		return;
87 
88 	for (bus = 0; bus < 256; bus++) {
89 		for (slot = 0; slot < 32; slot++) {
90 			for (func = 0; func < 8; func++) {
91 				u32 class;
92 				u8 type;
93 
94 				class = read_pci_config(bus, slot, func,
95 							PCI_CLASS_REVISION);
96 				if (class == 0xffffffff)
97 					continue;
98 
99 				early_dump_pci_device(bus, slot, func);
100 
101 				if (func == 0) {
102 					type = read_pci_config_byte(bus, slot,
103 								    func,
104 							       PCI_HEADER_TYPE);
105 					if (!(type & 0x80))
106 						break;
107 				}
108 			}
109 		}
110 	}
111 }
112