1// SPDX-License-Identifier: GPL-2.0
2#include <linux/sched.h>
3#include <linux/mm.h>
4#include <linux/uaccess.h>
5#include <linux/mmzone.h>
6#include <linux/ioport.h>
7#include <linux/seq_file.h>
8#include <linux/console.h>
9#include <linux/init.h>
10#include <linux/edd.h>
11#include <linux/dmi.h>
12#include <linux/pfn.h>
13#include <linux/pci.h>
14#include <linux/export.h>
15
16#include <asm/probe_roms.h>
17#include <asm/pci-direct.h>
18#include <asm/e820/api.h>
19#include <asm/mmzone.h>
20#include <asm/setup.h>
21#include <asm/sections.h>
22#include <asm/io.h>
23#include <asm/setup_arch.h>
24#include <asm/sev.h>
25
26static struct resource system_rom_resource = {
27 .name = "System ROM",
28 .start = 0xf0000,
29 .end = 0xfffff,
30 .flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
31};
32
33static struct resource extension_rom_resource = {
34 .name = "Extension ROM",
35 .start = 0xe0000,
36 .end = 0xeffff,
37 .flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
38};
39
40static struct resource adapter_rom_resources[] = { {
41 .name = "Adapter ROM",
42 .start = 0xc8000,
43 .end = 0,
44 .flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
45}, {
46 .name = "Adapter ROM",
47 .start = 0,
48 .end = 0,
49 .flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
50}, {
51 .name = "Adapter ROM",
52 .start = 0,
53 .end = 0,
54 .flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
55}, {
56 .name = "Adapter ROM",
57 .start = 0,
58 .end = 0,
59 .flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
60}, {
61 .name = "Adapter ROM",
62 .start = 0,
63 .end = 0,
64 .flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
65}, {
66 .name = "Adapter ROM",
67 .start = 0,
68 .end = 0,
69 .flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
70} };
71
72static struct resource video_rom_resource = {
73 .name = "Video ROM",
74 .start = 0xc0000,
75 .end = 0xc7fff,
76 .flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM
77};
78
79/* does this oprom support the given pci device, or any of the devices
80 * that the driver supports?
81 */
82static bool match_id(struct pci_dev *pdev, unsigned short vendor, unsigned short device)
83{
84 struct pci_driver *drv = to_pci_driver(pdev->dev.driver);
85 const struct pci_device_id *id;
86
87 if (pdev->vendor == vendor && pdev->device == device)
88 return true;
89
90 for (id = drv ? drv->id_table : NULL; id && id->vendor; id++)
91 if (id->vendor == vendor && id->device == device)
92 break;
93
94 return id && id->vendor;
95}
96
97static bool probe_list(struct pci_dev *pdev, unsigned short vendor,
98 const void *rom_list)
99{
100 unsigned short device;
101
102 do {
103 if (get_kernel_nofault(device, rom_list) != 0)
104 device = 0;
105
106 if (device && match_id(pdev, vendor, device))
107 break;
108
109 rom_list += 2;
110 } while (device);
111
112 return !!device;
113}
114
115static struct resource *find_oprom(struct pci_dev *pdev)
116{
117 struct resource *oprom = NULL;
118 int i;
119
120 for (i = 0; i < ARRAY_SIZE(adapter_rom_resources); i++) {
121 struct resource *res = &adapter_rom_resources[i];
122 unsigned short offset, vendor, device, list, rev;
123 const void *rom;
124
125 if (res->end == 0)
126 break;
127
128 rom = isa_bus_to_virt(address: res->start);
129 if (get_kernel_nofault(offset, rom + 0x18) != 0)
130 continue;
131
132 if (get_kernel_nofault(vendor, rom + offset + 0x4) != 0)
133 continue;
134
135 if (get_kernel_nofault(device, rom + offset + 0x6) != 0)
136 continue;
137
138 if (match_id(pdev, vendor, device)) {
139 oprom = res;
140 break;
141 }
142
143 if (get_kernel_nofault(list, rom + offset + 0x8) == 0 &&
144 get_kernel_nofault(rev, rom + offset + 0xc) == 0 &&
145 rev >= 3 && list &&
146 probe_list(pdev, vendor, rom_list: rom + offset + list)) {
147 oprom = res;
148 break;
149 }
150 }
151
152 return oprom;
153}
154
155void __iomem *pci_map_biosrom(struct pci_dev *pdev)
156{
157 struct resource *oprom = find_oprom(pdev);
158
159 if (!oprom)
160 return NULL;
161
162 return ioremap(offset: oprom->start, size: resource_size(res: oprom));
163}
164EXPORT_SYMBOL(pci_map_biosrom);
165
166void pci_unmap_biosrom(void __iomem *image)
167{
168 iounmap(addr: image);
169}
170EXPORT_SYMBOL(pci_unmap_biosrom);
171
172size_t pci_biosrom_size(struct pci_dev *pdev)
173{
174 struct resource *oprom = find_oprom(pdev);
175
176 return oprom ? resource_size(res: oprom) : 0;
177}
178EXPORT_SYMBOL(pci_biosrom_size);
179
180#define ROMSIGNATURE 0xaa55
181
182static int __init romsignature(const unsigned char *rom)
183{
184 const unsigned short * const ptr = (const unsigned short *)rom;
185 unsigned short sig;
186
187 return get_kernel_nofault(sig, ptr) == 0 && sig == ROMSIGNATURE;
188}
189
190static int __init romchecksum(const unsigned char *rom, unsigned long length)
191{
192 unsigned char sum, c;
193
194 for (sum = 0; length && get_kernel_nofault(c, rom++) == 0; length--)
195 sum += c;
196 return !length && !sum;
197}
198
199void __init probe_roms(void)
200{
201 unsigned long start, length, upper;
202 const unsigned char *rom;
203 unsigned char c;
204 int i;
205
206 /* video rom */
207 upper = adapter_rom_resources[0].start;
208 for (start = video_rom_resource.start; start < upper; start += 2048) {
209 rom = isa_bus_to_virt(address: start);
210 if (!romsignature(rom))
211 continue;
212
213 video_rom_resource.start = start;
214
215 if (get_kernel_nofault(c, rom + 2) != 0)
216 continue;
217
218 /* 0 < length <= 0x7f * 512, historically */
219 length = c * 512;
220
221 /* if checksum okay, trust length byte */
222 if (length && romchecksum(rom, length))
223 video_rom_resource.end = start + length - 1;
224
225 request_resource(root: &iomem_resource, new: &video_rom_resource);
226 break;
227 }
228
229 start = (video_rom_resource.end + 1 + 2047) & ~2047UL;
230 if (start < upper)
231 start = upper;
232
233 /* system rom */
234 request_resource(root: &iomem_resource, new: &system_rom_resource);
235 upper = system_rom_resource.start;
236
237 /* check for extension rom (ignore length byte!) */
238 rom = isa_bus_to_virt(address: extension_rom_resource.start);
239 if (romsignature(rom)) {
240 length = resource_size(res: &extension_rom_resource);
241 if (romchecksum(rom, length)) {
242 request_resource(root: &iomem_resource, new: &extension_rom_resource);
243 upper = extension_rom_resource.start;
244 }
245 }
246
247 /* check for adapter roms on 2k boundaries */
248 for (i = 0; i < ARRAY_SIZE(adapter_rom_resources) && start < upper; start += 2048) {
249 rom = isa_bus_to_virt(address: start);
250 if (!romsignature(rom))
251 continue;
252
253 if (get_kernel_nofault(c, rom + 2) != 0)
254 continue;
255
256 /* 0 < length <= 0x7f * 512, historically */
257 length = c * 512;
258
259 /* but accept any length that fits if checksum okay */
260 if (!length || start + length > upper || !romchecksum(rom, length))
261 continue;
262
263 adapter_rom_resources[i].start = start;
264 adapter_rom_resources[i].end = start + length - 1;
265 request_resource(root: &iomem_resource, new: &adapter_rom_resources[i]);
266
267 start = adapter_rom_resources[i++].end & ~2047UL;
268 }
269}
270
271