1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * amd76xrom.c
4 *
5 * Normal mappings of chips in physical memory
6 */
7
8 #include <linux/module.h>
9 #include <linux/types.h>
10 #include <linux/kernel.h>
11 #include <linux/init.h>
12 #include <linux/slab.h>
13 #include <asm/io.h>
14 #include <linux/mtd/mtd.h>
15 #include <linux/mtd/map.h>
16 #include <linux/mtd/cfi.h>
17 #include <linux/mtd/flashchip.h>
18 #include <linux/pci.h>
19 #include <linux/pci_ids.h>
20 #include <linux/list.h>
21
22
23 #define xstr(s) str(s)
24 #define str(s) #s
25 #define MOD_NAME xstr(KBUILD_BASENAME)
26
27 #define ADDRESS_NAME_LEN 18
28
29 #define ROM_PROBE_STEP_SIZE (64*1024) /* 64KiB */
30
31 struct amd76xrom_window {
32 void __iomem *virt;
33 unsigned long phys;
34 unsigned long size;
35 struct list_head maps;
36 struct resource rsrc;
37 struct pci_dev *pdev;
38 };
39
40 struct amd76xrom_map_info {
41 struct list_head list;
42 struct map_info map;
43 struct mtd_info *mtd;
44 struct resource rsrc;
45 char map_name[sizeof(MOD_NAME) + 2 + ADDRESS_NAME_LEN];
46 };
47
48 /* The 2 bits controlling the window size are often set to allow reading
49 * the BIOS, but too small to allow writing, since the lock registers are
50 * 4MiB lower in the address space than the data.
51 *
52 * This is intended to prevent flashing the bios, perhaps accidentally.
53 *
54 * This parameter allows the normal driver to over-ride the BIOS settings.
55 *
56 * The bits are 6 and 7. If both bits are set, it is a 5MiB window.
57 * If only the 7 Bit is set, it is a 4MiB window. Otherwise, a
58 * 64KiB window.
59 *
60 */
61 static uint win_size_bits;
62 module_param(win_size_bits, uint, 0);
63 MODULE_PARM_DESC(win_size_bits, "ROM window size bits override for 0x43 byte, normally set by BIOS.");
64
65 static struct amd76xrom_window amd76xrom_window = {
66 .maps = LIST_HEAD_INIT(amd76xrom_window.maps),
67 };
68
amd76xrom_cleanup(struct amd76xrom_window * window)69 static void amd76xrom_cleanup(struct amd76xrom_window *window)
70 {
71 struct amd76xrom_map_info *map, *scratch;
72 u8 byte;
73
74 if (window->pdev) {
75 /* Disable writes through the rom window */
76 pci_read_config_byte(window->pdev, 0x40, &byte);
77 pci_write_config_byte(window->pdev, 0x40, byte & ~1);
78 pci_dev_put(window->pdev);
79 }
80
81 /* Free all of the mtd devices */
82 list_for_each_entry_safe(map, scratch, &window->maps, list) {
83 if (map->rsrc.parent) {
84 release_resource(&map->rsrc);
85 }
86 mtd_device_unregister(map->mtd);
87 map_destroy(map->mtd);
88 list_del(&map->list);
89 kfree(map);
90 }
91 if (window->rsrc.parent)
92 release_resource(&window->rsrc);
93
94 if (window->virt) {
95 iounmap(window->virt);
96 window->virt = NULL;
97 window->phys = 0;
98 window->size = 0;
99 window->pdev = NULL;
100 }
101 }
102
103
amd76xrom_init_one(struct pci_dev * pdev,const struct pci_device_id * ent)104 static int amd76xrom_init_one(struct pci_dev *pdev,
105 const struct pci_device_id *ent)
106 {
107 static char *rom_probe_types[] = { "cfi_probe", "jedec_probe", NULL };
108 u8 byte;
109 struct amd76xrom_window *window = &amd76xrom_window;
110 struct amd76xrom_map_info *map = NULL;
111 unsigned long map_top;
112
113 /* Remember the pci dev I find the window in - already have a ref */
114 window->pdev = pdev;
115
116 /* Enable the selected rom window. This is often incorrectly
117 * set up by the BIOS, and the 4MiB offset for the lock registers
118 * requires the full 5MiB of window space.
119 *
120 * This 'write, then read' approach leaves the bits for
121 * other uses of the hardware info.
122 */
123 pci_read_config_byte(pdev, 0x43, &byte);
124 pci_write_config_byte(pdev, 0x43, byte | win_size_bits );
125
126 /* Assume the rom window is properly setup, and find it's size */
127 pci_read_config_byte(pdev, 0x43, &byte);
128 if ((byte & ((1<<7)|(1<<6))) == ((1<<7)|(1<<6))) {
129 window->phys = 0xffb00000; /* 5MiB */
130 }
131 else if ((byte & (1<<7)) == (1<<7)) {
132 window->phys = 0xffc00000; /* 4MiB */
133 }
134 else {
135 window->phys = 0xffff0000; /* 64KiB */
136 }
137 window->size = 0xffffffffUL - window->phys + 1UL;
138
139 /*
140 * Try to reserve the window mem region. If this fails then
141 * it is likely due to a fragment of the window being
142 * "reserved" by the BIOS. In the case that the
143 * request_mem_region() fails then once the rom size is
144 * discovered we will try to reserve the unreserved fragment.
145 */
146 window->rsrc.name = MOD_NAME;
147 window->rsrc.start = window->phys;
148 window->rsrc.end = window->phys + window->size - 1;
149 window->rsrc.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
150 if (request_resource(&iomem_resource, &window->rsrc)) {
151 window->rsrc.parent = NULL;
152 printk(KERN_ERR MOD_NAME
153 " %s(): Unable to register resource %pR - kernel bug?\n",
154 __func__, &window->rsrc);
155 return -EBUSY;
156 }
157
158
159 /* Enable writes through the rom window */
160 pci_read_config_byte(pdev, 0x40, &byte);
161 pci_write_config_byte(pdev, 0x40, byte | 1);
162
163 /* FIXME handle registers 0x80 - 0x8C the bios region locks */
164
165 /* For write accesses caches are useless */
166 window->virt = ioremap(window->phys, window->size);
167 if (!window->virt) {
168 printk(KERN_ERR MOD_NAME ": ioremap(%08lx, %08lx) failed\n",
169 window->phys, window->size);
170 goto out;
171 }
172
173 /* Get the first address to look for an rom chip at */
174 map_top = window->phys;
175 #if 1
176 /* The probe sequence run over the firmware hub lock
177 * registers sets them to 0x7 (no access).
178 * Probe at most the last 4M of the address space.
179 */
180 if (map_top < 0xffc00000) {
181 map_top = 0xffc00000;
182 }
183 #endif
184 /* Loop through and look for rom chips */
185 while((map_top - 1) < 0xffffffffUL) {
186 struct cfi_private *cfi;
187 unsigned long offset;
188 int i;
189
190 if (!map) {
191 map = kmalloc(sizeof(*map), GFP_KERNEL);
192 }
193 if (!map) {
194 printk(KERN_ERR MOD_NAME ": kmalloc failed");
195 goto out;
196 }
197 memset(map, 0, sizeof(*map));
198 INIT_LIST_HEAD(&map->list);
199 map->map.name = map->map_name;
200 map->map.phys = map_top;
201 offset = map_top - window->phys;
202 map->map.virt = (void __iomem *)
203 (((unsigned long)(window->virt)) + offset);
204 map->map.size = 0xffffffffUL - map_top + 1UL;
205 /* Set the name of the map to the address I am trying */
206 sprintf(map->map_name, "%s @%08Lx",
207 MOD_NAME, (unsigned long long)map->map.phys);
208
209 /* There is no generic VPP support */
210 for(map->map.bankwidth = 32; map->map.bankwidth;
211 map->map.bankwidth >>= 1)
212 {
213 char **probe_type;
214 /* Skip bankwidths that are not supported */
215 if (!map_bankwidth_supported(map->map.bankwidth))
216 continue;
217
218 /* Setup the map methods */
219 simple_map_init(&map->map);
220
221 /* Try all of the probe methods */
222 probe_type = rom_probe_types;
223 for(; *probe_type; probe_type++) {
224 map->mtd = do_map_probe(*probe_type, &map->map);
225 if (map->mtd)
226 goto found;
227 }
228 }
229 map_top += ROM_PROBE_STEP_SIZE;
230 continue;
231 found:
232 /* Trim the size if we are larger than the map */
233 if (map->mtd->size > map->map.size) {
234 printk(KERN_WARNING MOD_NAME
235 " rom(%llu) larger than window(%lu). fixing...\n",
236 (unsigned long long)map->mtd->size, map->map.size);
237 map->mtd->size = map->map.size;
238 }
239 if (window->rsrc.parent) {
240 /*
241 * Registering the MTD device in iomem may not be possible
242 * if there is a BIOS "reserved" and BUSY range. If this
243 * fails then continue anyway.
244 */
245 map->rsrc.name = map->map_name;
246 map->rsrc.start = map->map.phys;
247 map->rsrc.end = map->map.phys + map->mtd->size - 1;
248 map->rsrc.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
249 if (request_resource(&window->rsrc, &map->rsrc)) {
250 printk(KERN_ERR MOD_NAME
251 ": cannot reserve MTD resource\n");
252 map->rsrc.parent = NULL;
253 }
254 }
255
256 /* Make the whole region visible in the map */
257 map->map.virt = window->virt;
258 map->map.phys = window->phys;
259 cfi = map->map.fldrv_priv;
260 for(i = 0; i < cfi->numchips; i++) {
261 cfi->chips[i].start += offset;
262 }
263
264 /* Now that the mtd devices is complete claim and export it */
265 map->mtd->owner = THIS_MODULE;
266 if (mtd_device_register(map->mtd, NULL, 0)) {
267 map_destroy(map->mtd);
268 map->mtd = NULL;
269 goto out;
270 }
271
272
273 /* Calculate the new value of map_top */
274 map_top += map->mtd->size;
275
276 /* File away the map structure */
277 list_add(&map->list, &window->maps);
278 map = NULL;
279 }
280
281 out:
282 /* Free any left over map structures */
283 kfree(map);
284 /* See if I have any map structures */
285 if (list_empty(&window->maps)) {
286 amd76xrom_cleanup(window);
287 return -ENODEV;
288 }
289 return 0;
290 }
291
292
amd76xrom_remove_one(struct pci_dev * pdev)293 static void amd76xrom_remove_one(struct pci_dev *pdev)
294 {
295 struct amd76xrom_window *window = &amd76xrom_window;
296
297 amd76xrom_cleanup(window);
298 }
299
300 static const struct pci_device_id amd76xrom_pci_tbl[] = {
301 { PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_VIPER_7410,
302 PCI_ANY_ID, PCI_ANY_ID, },
303 { PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_VIPER_7440,
304 PCI_ANY_ID, PCI_ANY_ID, },
305 { PCI_VENDOR_ID_AMD, 0x7468 }, /* amd8111 support */
306 { 0, }
307 };
308
309 MODULE_DEVICE_TABLE(pci, amd76xrom_pci_tbl);
310
311 #if 0
312 static struct pci_driver amd76xrom_driver = {
313 .name = MOD_NAME,
314 .id_table = amd76xrom_pci_tbl,
315 .probe = amd76xrom_init_one,
316 .remove = amd76xrom_remove_one,
317 };
318 #endif
319
init_amd76xrom(void)320 static int __init init_amd76xrom(void)
321 {
322 struct pci_dev *pdev;
323 const struct pci_device_id *id;
324 pdev = NULL;
325 for(id = amd76xrom_pci_tbl; id->vendor; id++) {
326 pdev = pci_get_device(id->vendor, id->device, NULL);
327 if (pdev) {
328 break;
329 }
330 }
331 if (pdev) {
332 return amd76xrom_init_one(pdev, &amd76xrom_pci_tbl[0]);
333 }
334 return -ENXIO;
335 #if 0
336 return pci_register_driver(&amd76xrom_driver);
337 #endif
338 }
339
cleanup_amd76xrom(void)340 static void __exit cleanup_amd76xrom(void)
341 {
342 amd76xrom_remove_one(amd76xrom_window.pdev);
343 }
344
345 module_init(init_amd76xrom);
346 module_exit(cleanup_amd76xrom);
347
348 MODULE_LICENSE("GPL");
349 MODULE_AUTHOR("Eric Biederman <ebiederman@lnxi.com>");
350 MODULE_DESCRIPTION("MTD map driver for BIOS chips on the AMD76X southbridge");
351
