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