xref: /openbmc/linux/drivers/mtd/maps/ichxrom.c (revision 6c33a6f4)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * ichxrom.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 #define xstr(s) str(s)
23 #define str(s) #s
24 #define MOD_NAME xstr(KBUILD_BASENAME)
25 
26 #define ADDRESS_NAME_LEN 18
27 
28 #define ROM_PROBE_STEP_SIZE (64*1024) /* 64KiB */
29 
30 #define BIOS_CNTL	0x4e
31 #define FWH_DEC_EN1	0xE3
32 #define FWH_DEC_EN2	0xF0
33 #define FWH_SEL1	0xE8
34 #define FWH_SEL2	0xEE
35 
36 struct ichxrom_window {
37 	void __iomem* virt;
38 	unsigned long phys;
39 	unsigned long size;
40 	struct list_head maps;
41 	struct resource rsrc;
42 	struct pci_dev *pdev;
43 };
44 
45 struct ichxrom_map_info {
46 	struct list_head list;
47 	struct map_info map;
48 	struct mtd_info *mtd;
49 	struct resource rsrc;
50 	char map_name[sizeof(MOD_NAME) + 2 + ADDRESS_NAME_LEN];
51 };
52 
53 static struct ichxrom_window ichxrom_window = {
54 	.maps = LIST_HEAD_INIT(ichxrom_window.maps),
55 };
56 
57 static void ichxrom_cleanup(struct ichxrom_window *window)
58 {
59 	struct ichxrom_map_info *map, *scratch;
60 	u16 word;
61 	int ret;
62 
63 	/* Disable writes through the rom window */
64 	ret = pci_read_config_word(window->pdev, BIOS_CNTL, &word);
65 	if (!ret)
66 		pci_write_config_word(window->pdev, BIOS_CNTL, word & ~1);
67 	pci_dev_put(window->pdev);
68 
69 	/* Free all of the mtd devices */
70 	list_for_each_entry_safe(map, scratch, &window->maps, list) {
71 		if (map->rsrc.parent)
72 			release_resource(&map->rsrc);
73 		mtd_device_unregister(map->mtd);
74 		map_destroy(map->mtd);
75 		list_del(&map->list);
76 		kfree(map);
77 	}
78 	if (window->rsrc.parent)
79 		release_resource(&window->rsrc);
80 	if (window->virt) {
81 		iounmap(window->virt);
82 		window->virt = NULL;
83 		window->phys = 0;
84 		window->size = 0;
85 		window->pdev = NULL;
86 	}
87 }
88 
89 
90 static int __init ichxrom_init_one(struct pci_dev *pdev,
91 				   const struct pci_device_id *ent)
92 {
93 	static char *rom_probe_types[] = { "cfi_probe", "jedec_probe", NULL };
94 	struct ichxrom_window *window = &ichxrom_window;
95 	struct ichxrom_map_info *map = NULL;
96 	unsigned long map_top;
97 	u8 byte;
98 	u16 word;
99 
100 	/* For now I just handle the ichx and I assume there
101 	 * are not a lot of resources up at the top of the address
102 	 * space.  It is possible to handle other devices in the
103 	 * top 16MB but it is very painful.  Also since
104 	 * you can only really attach a FWH to an ICHX there
105 	 * a number of simplifications you can make.
106 	 *
107 	 * Also you can page firmware hubs if an 8MB window isn't enough
108 	 * but don't currently handle that case either.
109 	 */
110 	window->pdev = pdev;
111 
112 	/* Find a region continuous to the end of the ROM window  */
113 	window->phys = 0;
114 	pci_read_config_byte(pdev, FWH_DEC_EN1, &byte);
115 	if (byte == 0xff) {
116 		window->phys = 0xffc00000;
117 		pci_read_config_byte(pdev, FWH_DEC_EN2, &byte);
118 		if ((byte & 0x0f) == 0x0f) {
119 			window->phys = 0xff400000;
120 		}
121 		else if ((byte & 0x0e) == 0x0e) {
122 			window->phys = 0xff500000;
123 		}
124 		else if ((byte & 0x0c) == 0x0c) {
125 			window->phys = 0xff600000;
126 		}
127 		else if ((byte & 0x08) == 0x08) {
128 			window->phys = 0xff700000;
129 		}
130 	}
131 	else if ((byte & 0xfe) == 0xfe) {
132 		window->phys = 0xffc80000;
133 	}
134 	else if ((byte & 0xfc) == 0xfc) {
135 		window->phys = 0xffd00000;
136 	}
137 	else if ((byte & 0xf8) == 0xf8) {
138 		window->phys = 0xffd80000;
139 	}
140 	else if ((byte & 0xf0) == 0xf0) {
141 		window->phys = 0xffe00000;
142 	}
143 	else if ((byte & 0xe0) == 0xe0) {
144 		window->phys = 0xffe80000;
145 	}
146 	else if ((byte & 0xc0) == 0xc0) {
147 		window->phys = 0xfff00000;
148 	}
149 	else if ((byte & 0x80) == 0x80) {
150 		window->phys = 0xfff80000;
151 	}
152 
153 	if (window->phys == 0) {
154 		printk(KERN_ERR MOD_NAME ": Rom window is closed\n");
155 		goto out;
156 	}
157 	window->phys -= 0x400000UL;
158 	window->size = (0xffffffffUL - window->phys) + 1UL;
159 
160 	/* Enable writes through the rom window */
161 	pci_read_config_word(pdev, BIOS_CNTL, &word);
162 	if (!(word & 1)  && (word & (1<<1))) {
163 		/* The BIOS will generate an error if I enable
164 		 * this device, so don't even try.
165 		 */
166 		printk(KERN_ERR MOD_NAME ": firmware access control, I can't enable writes\n");
167 		goto out;
168 	}
169 	pci_write_config_word(pdev, BIOS_CNTL, word | 1);
170 
171 	/*
172 	 * Try to reserve the window mem region.  If this fails then
173 	 * it is likely due to the window being "reserved" by the BIOS.
174 	 */
175 	window->rsrc.name = MOD_NAME;
176 	window->rsrc.start = window->phys;
177 	window->rsrc.end   = window->phys + window->size - 1;
178 	window->rsrc.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
179 	if (request_resource(&iomem_resource, &window->rsrc)) {
180 		window->rsrc.parent = NULL;
181 		printk(KERN_DEBUG MOD_NAME ": "
182 		       "%s(): Unable to register resource %pR - kernel bug?\n",
183 		       __func__, &window->rsrc);
184 	}
185 
186 	/* Map the firmware hub into my address space. */
187 	window->virt = ioremap(window->phys, window->size);
188 	if (!window->virt) {
189 		printk(KERN_ERR MOD_NAME ": ioremap(%08lx, %08lx) failed\n",
190 			window->phys, window->size);
191 		goto out;
192 	}
193 
194 	/* Get the first address to look for an rom chip at */
195 	map_top = window->phys;
196 	if ((window->phys & 0x3fffff) != 0) {
197 		map_top = window->phys + 0x400000;
198 	}
199 #if 1
200 	/* The probe sequence run over the firmware hub lock
201 	 * registers sets them to 0x7 (no access).
202 	 * Probe at most the last 4M of the address space.
203 	 */
204 	if (map_top < 0xffc00000) {
205 		map_top = 0xffc00000;
206 	}
207 #endif
208 	/* Loop through and look for rom chips */
209 	while((map_top - 1) < 0xffffffffUL) {
210 		struct cfi_private *cfi;
211 		unsigned long offset;
212 		int i;
213 
214 		if (!map) {
215 			map = kmalloc(sizeof(*map), GFP_KERNEL);
216 		}
217 		if (!map) {
218 			printk(KERN_ERR MOD_NAME ": kmalloc failed");
219 			goto out;
220 		}
221 		memset(map, 0, sizeof(*map));
222 		INIT_LIST_HEAD(&map->list);
223 		map->map.name = map->map_name;
224 		map->map.phys = map_top;
225 		offset = map_top - window->phys;
226 		map->map.virt = (void __iomem *)
227 			(((unsigned long)(window->virt)) + offset);
228 		map->map.size = 0xffffffffUL - map_top + 1UL;
229 		/* Set the name of the map to the address I am trying */
230 		sprintf(map->map_name, "%s @%08Lx",
231 			MOD_NAME, (unsigned long long)map->map.phys);
232 
233 		/* Firmware hubs only use vpp when being programmed
234 		 * in a factory setting.  So in-place programming
235 		 * needs to use a different method.
236 		 */
237 		for(map->map.bankwidth = 32; map->map.bankwidth;
238 			map->map.bankwidth >>= 1)
239 		{
240 			char **probe_type;
241 			/* Skip bankwidths that are not supported */
242 			if (!map_bankwidth_supported(map->map.bankwidth))
243 				continue;
244 
245 			/* Setup the map methods */
246 			simple_map_init(&map->map);
247 
248 			/* Try all of the probe methods */
249 			probe_type = rom_probe_types;
250 			for(; *probe_type; probe_type++) {
251 				map->mtd = do_map_probe(*probe_type, &map->map);
252 				if (map->mtd)
253 					goto found;
254 			}
255 		}
256 		map_top += ROM_PROBE_STEP_SIZE;
257 		continue;
258 	found:
259 		/* Trim the size if we are larger than the map */
260 		if (map->mtd->size > map->map.size) {
261 			printk(KERN_WARNING MOD_NAME
262 				" rom(%llu) larger than window(%lu). fixing...\n",
263 				(unsigned long long)map->mtd->size, map->map.size);
264 			map->mtd->size = map->map.size;
265 		}
266 		if (window->rsrc.parent) {
267 			/*
268 			 * Registering the MTD device in iomem may not be possible
269 			 * if there is a BIOS "reserved" and BUSY range.  If this
270 			 * fails then continue anyway.
271 			 */
272 			map->rsrc.name  = map->map_name;
273 			map->rsrc.start = map->map.phys;
274 			map->rsrc.end   = map->map.phys + map->mtd->size - 1;
275 			map->rsrc.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
276 			if (request_resource(&window->rsrc, &map->rsrc)) {
277 				printk(KERN_ERR MOD_NAME
278 					": cannot reserve MTD resource\n");
279 				map->rsrc.parent = NULL;
280 			}
281 		}
282 
283 		/* Make the whole region visible in the map */
284 		map->map.virt = window->virt;
285 		map->map.phys = window->phys;
286 		cfi = map->map.fldrv_priv;
287 		for(i = 0; i < cfi->numchips; i++) {
288 			cfi->chips[i].start += offset;
289 		}
290 
291 		/* Now that the mtd devices is complete claim and export it */
292 		map->mtd->owner = THIS_MODULE;
293 		if (mtd_device_register(map->mtd, NULL, 0)) {
294 			map_destroy(map->mtd);
295 			map->mtd = NULL;
296 			goto out;
297 		}
298 
299 
300 		/* Calculate the new value of map_top */
301 		map_top += map->mtd->size;
302 
303 		/* File away the map structure */
304 		list_add(&map->list, &window->maps);
305 		map = NULL;
306 	}
307 
308  out:
309 	/* Free any left over map structures */
310 	kfree(map);
311 
312 	/* See if I have any map structures */
313 	if (list_empty(&window->maps)) {
314 		ichxrom_cleanup(window);
315 		return -ENODEV;
316 	}
317 	return 0;
318 }
319 
320 
321 static void ichxrom_remove_one(struct pci_dev *pdev)
322 {
323 	struct ichxrom_window *window = &ichxrom_window;
324 	ichxrom_cleanup(window);
325 }
326 
327 static const struct pci_device_id ichxrom_pci_tbl[] = {
328 	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801BA_0,
329 	  PCI_ANY_ID, PCI_ANY_ID, },
330 	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801CA_0,
331 	  PCI_ANY_ID, PCI_ANY_ID, },
332 	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801DB_0,
333 	  PCI_ANY_ID, PCI_ANY_ID, },
334 	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801EB_0,
335 	  PCI_ANY_ID, PCI_ANY_ID, },
336 	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ESB_1,
337 	  PCI_ANY_ID, PCI_ANY_ID, },
338 	{ 0, },
339 };
340 
341 #if 0
342 MODULE_DEVICE_TABLE(pci, ichxrom_pci_tbl);
343 
344 static struct pci_driver ichxrom_driver = {
345 	.name =		MOD_NAME,
346 	.id_table =	ichxrom_pci_tbl,
347 	.probe =	ichxrom_init_one,
348 	.remove =	ichxrom_remove_one,
349 };
350 #endif
351 
352 static int __init init_ichxrom(void)
353 {
354 	struct pci_dev *pdev;
355 	const struct pci_device_id *id;
356 
357 	pdev = NULL;
358 	for (id = ichxrom_pci_tbl; id->vendor; id++) {
359 		pdev = pci_get_device(id->vendor, id->device, NULL);
360 		if (pdev) {
361 			break;
362 		}
363 	}
364 	if (pdev) {
365 		return ichxrom_init_one(pdev, &ichxrom_pci_tbl[0]);
366 	}
367 	return -ENXIO;
368 #if 0
369 	return pci_register_driver(&ichxrom_driver);
370 #endif
371 }
372 
373 static void __exit cleanup_ichxrom(void)
374 {
375 	ichxrom_remove_one(ichxrom_window.pdev);
376 }
377 
378 module_init(init_ichxrom);
379 module_exit(cleanup_ichxrom);
380 
381 MODULE_LICENSE("GPL");
382 MODULE_AUTHOR("Eric Biederman <ebiederman@lnxi.com>");
383 MODULE_DESCRIPTION("MTD map driver for BIOS chips on the ICHX southbridge");
384