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
|
/*
* mmconfig.c - Low-level direct PCI config space access via MMCONFIG
*
* This is an 64bit optimized version that always keeps the full mmconfig
* space mapped. This allows lockless config space operation.
*/
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/acpi.h>
#include <linux/bitmap.h>
#include <asm/e820.h>
#include "pci.h"
/* aperture is up to 256MB but BIOS may reserve less */
#define MMCONFIG_APER_MIN (2 * 1024*1024)
#define MMCONFIG_APER_MAX (256 * 1024*1024)
/* Verify the first 16 busses. We assume that systems with more busses
get MCFG right. */
#define MAX_CHECK_BUS 16
static DECLARE_BITMAP(fallback_slots, 32*MAX_CHECK_BUS);
/* Static virtual mapping of the MMCONFIG aperture */
struct mmcfg_virt {
struct acpi_table_mcfg_config *cfg;
char __iomem *virt;
};
static struct mmcfg_virt *pci_mmcfg_virt;
static char __iomem *get_virt(unsigned int seg, unsigned bus)
{
int cfg_num = -1;
struct acpi_table_mcfg_config *cfg;
while (1) {
++cfg_num;
if (cfg_num >= pci_mmcfg_config_num)
break;
cfg = pci_mmcfg_virt[cfg_num].cfg;
if (cfg->pci_segment_group_number != seg)
continue;
if ((cfg->start_bus_number <= bus) &&
(cfg->end_bus_number >= bus))
return pci_mmcfg_virt[cfg_num].virt;
}
/* Handle more broken MCFG tables on Asus etc.
They only contain a single entry for bus 0-0. Assume
this applies to all busses. */
cfg = &pci_mmcfg_config[0];
if (pci_mmcfg_config_num == 1 &&
cfg->pci_segment_group_number == 0 &&
(cfg->start_bus_number | cfg->end_bus_number) == 0)
return pci_mmcfg_virt[0].virt;
/* Fall back to type 0 */
return NULL;
}
static char __iomem *pci_dev_base(unsigned int seg, unsigned int bus, unsigned int devfn)
{
char __iomem *addr;
if (seg == 0 && bus < MAX_CHECK_BUS &&
test_bit(32*bus + PCI_SLOT(devfn), fallback_slots))
return NULL;
addr = get_virt(seg, bus);
if (!addr)
return NULL;
return addr + ((bus << 20) | (devfn << 12));
}
static int pci_mmcfg_read(unsigned int seg, unsigned int bus,
unsigned int devfn, int reg, int len, u32 *value)
{
char __iomem *addr;
/* Why do we have this when nobody checks it. How about a BUG()!? -AK */
if (unlikely((bus > 255) || (devfn > 255) || (reg > 4095))) {
*value = -1;
return -EINVAL;
}
addr = pci_dev_base(seg, bus, devfn);
if (!addr)
return pci_conf1_read(seg,bus,devfn,reg,len,value);
switch (len) {
case 1:
*value = readb(addr + reg);
break;
case 2:
*value = readw(addr + reg);
break;
case 4:
*value = readl(addr + reg);
break;
}
return 0;
}
static int pci_mmcfg_write(unsigned int seg, unsigned int bus,
unsigned int devfn, int reg, int len, u32 value)
{
char __iomem *addr;
/* Why do we have this when nobody checks it. How about a BUG()!? -AK */
if (unlikely((bus > 255) || (devfn > 255) || (reg > 4095)))
return -EINVAL;
addr = pci_dev_base(seg, bus, devfn);
if (!addr)
return pci_conf1_write(seg,bus,devfn,reg,len,value);
switch (len) {
case 1:
writeb(value, addr + reg);
break;
case 2:
writew(value, addr + reg);
break;
case 4:
writel(value, addr + reg);
break;
}
return 0;
}
static struct pci_raw_ops pci_mmcfg = {
.read = pci_mmcfg_read,
.write = pci_mmcfg_write,
};
/* K8 systems have some devices (typically in the builtin northbridge)
that are only accessible using type1
Normally this can be expressed in the MCFG by not listing them
and assigning suitable _SEGs, but this isn't implemented in some BIOS.
Instead try to discover all devices on bus 0 that are unreachable using MM
and fallback for them. */
static __init void unreachable_devices(void)
{
int i, k;
/* Use the max bus number from ACPI here? */
for (k = 0; k < MAX_CHECK_BUS; k++) {
for (i = 0; i < 32; i++) {
u32 val1;
char __iomem *addr;
pci_conf1_read(0, k, PCI_DEVFN(i,0), 0, 4, &val1);
if (val1 == 0xffffffff)
continue;
addr = pci_dev_base(0, k, PCI_DEVFN(i, 0));
if (addr == NULL|| readl(addr) != val1) {
set_bit(i + 32*k, fallback_slots);
printk(KERN_NOTICE "PCI: No mmconfig possible"
" on device %02x:%02x\n", k, i);
}
}
}
}
static __init void pci_mmcfg_insert_resources(void)
{
#define PCI_MMCFG_RESOURCE_NAME_LEN 19
int i;
struct resource *res;
char *names;
unsigned num_buses;
res = kcalloc(PCI_MMCFG_RESOURCE_NAME_LEN + sizeof(*res),
pci_mmcfg_config_num, GFP_KERNEL);
if (!res) {
printk(KERN_ERR "PCI: Unable to allocate MMCONFIG resources\n");
return;
}
names = (void *)&res[pci_mmcfg_config_num];
for (i = 0; i < pci_mmcfg_config_num; i++, res++) {
num_buses = pci_mmcfg_config[i].end_bus_number -
pci_mmcfg_config[i].start_bus_number + 1;
res->name = names;
snprintf(names, PCI_MMCFG_RESOURCE_NAME_LEN, "PCI MMCONFIG %u",
pci_mmcfg_config[i].pci_segment_group_number);
res->start = pci_mmcfg_config[i].base_address;
res->end = res->start + (num_buses << 20) - 1;
res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
insert_resource(&iomem_resource, res);
names += PCI_MMCFG_RESOURCE_NAME_LEN;
}
}
void __init pci_mmcfg_init(int type)
{
int i;
if ((pci_probe & PCI_PROBE_MMCONF) == 0)
return;
acpi_table_parse(ACPI_MCFG, acpi_parse_mcfg);
if ((pci_mmcfg_config_num == 0) ||
(pci_mmcfg_config == NULL) ||
(pci_mmcfg_config[0].base_address == 0))
return;
/* Only do this check when type 1 works. If it doesn't work
assume we run on a Mac and always use MCFG */
if (type == 1 && !e820_all_mapped(pci_mmcfg_config[0].base_address,
pci_mmcfg_config[0].base_address + MMCONFIG_APER_MIN,
E820_RESERVED)) {
printk(KERN_ERR "PCI: BIOS Bug: MCFG area at %x is not E820-reserved\n",
pci_mmcfg_config[0].base_address);
printk(KERN_ERR "PCI: Not using MMCONFIG.\n");
return;
}
/* RED-PEN i386 doesn't do _nocache right now */
pci_mmcfg_virt = kmalloc(sizeof(*pci_mmcfg_virt) * pci_mmcfg_config_num, GFP_KERNEL);
if (pci_mmcfg_virt == NULL) {
printk("PCI: Can not allocate memory for mmconfig structures\n");
return;
}
for (i = 0; i < pci_mmcfg_config_num; ++i) {
pci_mmcfg_virt[i].cfg = &pci_mmcfg_config[i];
pci_mmcfg_virt[i].virt = ioremap_nocache(pci_mmcfg_config[i].base_address,
MMCONFIG_APER_MAX);
if (!pci_mmcfg_virt[i].virt) {
printk("PCI: Cannot map mmconfig aperture for segment %d\n",
pci_mmcfg_config[i].pci_segment_group_number);
return;
}
printk(KERN_INFO "PCI: Using MMCONFIG at %x\n", pci_mmcfg_config[i].base_address);
}
unreachable_devices();
pci_mmcfg_insert_resources();
raw_pci_ops = &pci_mmcfg;
pci_probe = (pci_probe & ~PCI_PROBE_MASK) | PCI_PROBE_MMCONF;
}
|
