1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
|
/*
* direct.c - Low-level direct PCI config space access
*/
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/dmi.h>
#include "pci.h"
/*
* Functions for accessing PCI configuration space with type 1 accesses
*/
#define PCI_CONF1_ADDRESS(bus, devfn, reg) \
(0x80000000 | (bus << 16) | (devfn << 8) | (reg & ~3))
int pci_conf1_read(unsigned int seg, unsigned int bus,
unsigned int devfn, int reg, int len, u32 *value)
{
unsigned long flags;
if ((bus > 255) || (devfn > 255) || (reg > 255)) {
*value = -1;
return -EINVAL;
}
spin_lock_irqsave(&pci_config_lock, flags);
outl(PCI_CONF1_ADDRESS(bus, devfn, reg), 0xCF8);
switch (len) {
case 1:
*value = inb(0xCFC + (reg & 3));
break;
case 2:
*value = inw(0xCFC + (reg & 2));
break;
case 4:
*value = inl(0xCFC);
break;
}
spin_unlock_irqrestore(&pci_config_lock, flags);
return 0;
}
int pci_conf1_write(unsigned int seg, unsigned int bus,
unsigned int devfn, int reg, int len, u32 value)
{
unsigned long flags;
if ((bus > 255) || (devfn > 255) || (reg > 255))
return -EINVAL;
spin_lock_irqsave(&pci_config_lock, flags);
outl(PCI_CONF1_ADDRESS(bus, devfn, reg), 0xCF8);
switch (len) {
case 1:
outb((u8)value, 0xCFC + (reg & 3));
break;
case 2:
outw((u16)value, 0xCFC + (reg & 2));
break;
case 4:
outl((u32)value, 0xCFC);
break;
}
spin_unlock_irqrestore(&pci_config_lock, flags);
return 0;
}
#undef PCI_CONF1_ADDRESS
struct pci_raw_ops pci_direct_conf1 = {
.read = pci_conf1_read,
.write = pci_conf1_write,
};
/*
* Functions for accessing PCI configuration space with type 2 accesses
*/
#define PCI_CONF2_ADDRESS(dev, reg) (u16)(0xC000 | (dev << 8) | reg)
static int pci_conf2_read(unsigned int seg, unsigned int bus,
unsigned int devfn, int reg, int len, u32 *value)
{
unsigned long flags;
int dev, fn;
if ((bus > 255) || (devfn > 255) || (reg > 255)) {
*value = -1;
return -EINVAL;
}
dev = PCI_SLOT(devfn);
fn = PCI_FUNC(devfn);
if (dev & 0x10)
return PCIBIOS_DEVICE_NOT_FOUND;
spin_lock_irqsave(&pci_config_lock, flags);
outb((u8)(0xF0 | (fn << 1)), 0xCF8);
outb((u8)bus, 0xCFA);
switch (len) {
case 1:
*value = inb(PCI_CONF2_ADDRESS(dev, reg));
break;
case 2:
*value = inw(PCI_CONF2_ADDRESS(dev, reg));
break;
case 4:
*value = inl(PCI_CONF2_ADDRESS(dev, reg));
break;
}
outb(0, 0xCF8);
spin_unlock_irqrestore(&pci_config_lock, flags);
return 0;
}
static int pci_conf2_write(unsigned int seg, unsigned int bus,
unsigned int devfn, int reg, int len, u32 value)
{
unsigned long flags;
int dev, fn;
if ((bus > 255) || (devfn > 255) || (reg > 255))
return -EINVAL;
dev = PCI_SLOT(devfn);
fn = PCI_FUNC(devfn);
if (dev & 0x10)
return PCIBIOS_DEVICE_NOT_FOUND;
spin_lock_irqsave(&pci_config_lock, flags);
outb((u8)(0xF0 | (fn << 1)), 0xCF8);
outb((u8)bus, 0xCFA);
switch (len) {
case 1:
outb((u8)value, PCI_CONF2_ADDRESS(dev, reg));
break;
case 2:
outw((u16)value, PCI_CONF2_ADDRESS(dev, reg));
break;
case 4:
outl((u32)value, PCI_CONF2_ADDRESS(dev, reg));
break;
}
outb(0, 0xCF8);
spin_unlock_irqrestore(&pci_config_lock, flags);
return 0;
}
#undef PCI_CONF2_ADDRESS
static struct pci_raw_ops pci_direct_conf2 = {
.read = pci_conf2_read,
.write = pci_conf2_write,
};
/*
* Before we decide to use direct hardware access mechanisms, we try to do some
* trivial checks to ensure it at least _seems_ to be working -- we just test
* whether bus 00 contains a host bridge (this is similar to checking
* techniques used in XFree86, but ours should be more reliable since we
* attempt to make use of direct access hints provided by the PCI BIOS).
*
* This should be close to trivial, but it isn't, because there are buggy
* chipsets (yes, you guessed it, by Intel and Compaq) that have no class ID.
*/
static int __init pci_sanity_check(struct pci_raw_ops *o)
{
u32 x = 0;
int devfn;
if (pci_probe & PCI_NO_CHECKS)
return 1;
/* Assume Type 1 works for newer systems.
This handles machines that don't have anything on PCI Bus 0. */
if (dmi_get_year(DMI_BIOS_DATE) >= 2001)
return 1;
for (devfn = 0; devfn < 0x100; devfn++) {
if (o->read(0, 0, devfn, PCI_CLASS_DEVICE, 2, &x))
continue;
if (x == PCI_CLASS_BRIDGE_HOST || x == PCI_CLASS_DISPLAY_VGA)
return 1;
if (o->read(0, 0, devfn, PCI_VENDOR_ID, 2, &x))
continue;
if (x == PCI_VENDOR_ID_INTEL || x == PCI_VENDOR_ID_COMPAQ)
return 1;
}
DBG(KERN_WARNING "PCI: Sanity check failed\n");
return 0;
}
static int __init pci_check_type1(void)
{
unsigned long flags;
unsigned int tmp;
int works = 0;
local_irq_save(flags);
outb(0x01, 0xCFB);
tmp = inl(0xCF8);
outl(0x80000000, 0xCF8);
if (inl(0xCF8) == 0x80000000 && pci_sanity_check(&pci_direct_conf1)) {
works = 1;
}
outl(tmp, 0xCF8);
local_irq_restore(flags);
return works;
}
static int __init pci_check_type2(void)
{
unsigned long flags;
int works = 0;
local_irq_save(flags);
outb(0x00, 0xCFB);
outb(0x00, 0xCF8);
outb(0x00, 0xCFA);
if (inb(0xCF8) == 0x00 && inb(0xCFA) == 0x00 &&
pci_sanity_check(&pci_direct_conf2)) {
works = 1;
}
local_irq_restore(flags);
return works;
}
void __init pci_direct_init(int type)
{
if (type == 0)
return;
printk(KERN_INFO "PCI: Using configuration type %d\n", type);
if (type == 1)
raw_pci_ops = &pci_direct_conf1;
else
raw_pci_ops = &pci_direct_conf2;
}
int __init pci_direct_probe(void)
{
struct resource *region, *region2;
if ((pci_probe & PCI_PROBE_CONF1) == 0)
goto type2;
region = request_region(0xCF8, 8, "PCI conf1");
if (!region)
goto type2;
if (pci_check_type1())
return 1;
release_resource(region);
type2:
if ((pci_probe & PCI_PROBE_CONF2) == 0)
return 0;
region = request_region(0xCF8, 4, "PCI conf2");
if (!region)
return 0;
region2 = request_region(0xC000, 0x1000, "PCI conf2");
if (!region2)
goto fail2;
if (pci_check_type2()) {
printk(KERN_INFO "PCI: Using configuration type 2\n");
raw_pci_ops = &pci_direct_conf2;
return 2;
}
release_resource(region2);
fail2:
release_resource(region);
return 0;
}
|
