xref: /openbmc/linux/drivers/mtd/maps/esb2rom.c (revision d9fd5a71)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * esb2rom.c
4  *
5  * Normal mappings of flash chips in physical memory
6  * through the Intel ESB2 Southbridge.
7  *
8  * This was derived from ichxrom.c in May 2006 by
9  *	Lew Glendenning <lglendenning@lnxi.com>
10  *
11  * Eric Biederman, of course, was a major help in this effort.
12  */
13 
14 #include <linux/module.h>
15 #include <linux/types.h>
16 #include <linux/kernel.h>
17 #include <linux/init.h>
18 #include <linux/slab.h>
19 #include <asm/io.h>
20 #include <linux/mtd/mtd.h>
21 #include <linux/mtd/map.h>
22 #include <linux/mtd/cfi.h>
23 #include <linux/mtd/flashchip.h>
24 #include <linux/pci.h>
25 #include <linux/pci_ids.h>
26 #include <linux/list.h>
27 
28 #define MOD_NAME KBUILD_BASENAME
29 
30 #define ADDRESS_NAME_LEN 18
31 
32 #define ROM_PROBE_STEP_SIZE (64*1024) /* 64KiB */
33 
34 #define BIOS_CNTL		0xDC
35 #define BIOS_LOCK_ENABLE	0x02
36 #define BIOS_WRITE_ENABLE	0x01
37 
38 /* This became a 16-bit register, and EN2 has disappeared */
39 #define FWH_DEC_EN1	0xD8
40 #define FWH_F8_EN	0x8000
41 #define FWH_F0_EN	0x4000
42 #define FWH_E8_EN	0x2000
43 #define FWH_E0_EN	0x1000
44 #define FWH_D8_EN	0x0800
45 #define FWH_D0_EN	0x0400
46 #define FWH_C8_EN	0x0200
47 #define FWH_C0_EN	0x0100
48 #define FWH_LEGACY_F_EN	0x0080
49 #define FWH_LEGACY_E_EN	0x0040
50 /* reserved  0x0020 and 0x0010 */
51 #define FWH_70_EN	0x0008
52 #define FWH_60_EN	0x0004
53 #define FWH_50_EN	0x0002
54 #define FWH_40_EN	0x0001
55 
56 /* these are 32-bit values */
57 #define FWH_SEL1	0xD0
58 #define FWH_SEL2	0xD4
59 
60 #define FWH_8MiB	(FWH_F8_EN | FWH_F0_EN | FWH_E8_EN | FWH_E0_EN | \
61 			 FWH_D8_EN | FWH_D0_EN | FWH_C8_EN | FWH_C0_EN | \
62 			 FWH_70_EN | FWH_60_EN | FWH_50_EN | FWH_40_EN)
63 
64 #define FWH_7MiB	(FWH_F8_EN | FWH_F0_EN | FWH_E8_EN | FWH_E0_EN | \
65 			 FWH_D8_EN | FWH_D0_EN | FWH_C8_EN | FWH_C0_EN | \
66 			 FWH_70_EN | FWH_60_EN | FWH_50_EN)
67 
68 #define FWH_6MiB	(FWH_F8_EN | FWH_F0_EN | FWH_E8_EN | FWH_E0_EN | \
69 			 FWH_D8_EN | FWH_D0_EN | FWH_C8_EN | FWH_C0_EN | \
70 			 FWH_70_EN | FWH_60_EN)
71 
72 #define FWH_5MiB	(FWH_F8_EN | FWH_F0_EN | FWH_E8_EN | FWH_E0_EN | \
73 			 FWH_D8_EN | FWH_D0_EN | FWH_C8_EN | FWH_C0_EN | \
74 			 FWH_70_EN)
75 
76 #define FWH_4MiB	(FWH_F8_EN | FWH_F0_EN | FWH_E8_EN | FWH_E0_EN | \
77 			 FWH_D8_EN | FWH_D0_EN | FWH_C8_EN | FWH_C0_EN)
78 
79 #define FWH_3_5MiB	(FWH_F8_EN | FWH_F0_EN | FWH_E8_EN | FWH_E0_EN | \
80 			 FWH_D8_EN | FWH_D0_EN | FWH_C8_EN)
81 
82 #define FWH_3MiB	(FWH_F8_EN | FWH_F0_EN | FWH_E8_EN | FWH_E0_EN | \
83 			 FWH_D8_EN | FWH_D0_EN)
84 
85 #define FWH_2_5MiB	(FWH_F8_EN | FWH_F0_EN | FWH_E8_EN | FWH_E0_EN | \
86 			 FWH_D8_EN)
87 
88 #define FWH_2MiB	(FWH_F8_EN | FWH_F0_EN | FWH_E8_EN | FWH_E0_EN)
89 
90 #define FWH_1_5MiB	(FWH_F8_EN | FWH_F0_EN | FWH_E8_EN)
91 
92 #define FWH_1MiB	(FWH_F8_EN | FWH_F0_EN)
93 
94 #define FWH_0_5MiB	(FWH_F8_EN)
95 
96 
97 struct esb2rom_window {
98 	void __iomem* virt;
99 	unsigned long phys;
100 	unsigned long size;
101 	struct list_head maps;
102 	struct resource rsrc;
103 	struct pci_dev *pdev;
104 };
105 
106 struct esb2rom_map_info {
107 	struct list_head list;
108 	struct map_info map;
109 	struct mtd_info *mtd;
110 	struct resource rsrc;
111 	char map_name[sizeof(MOD_NAME) + 2 + ADDRESS_NAME_LEN];
112 };
113 
114 static struct esb2rom_window esb2rom_window = {
115 	.maps = LIST_HEAD_INIT(esb2rom_window.maps),
116 };
117 
118 static void esb2rom_cleanup(struct esb2rom_window *window)
119 {
120 	struct esb2rom_map_info *map, *scratch;
121 	u8 byte;
122 
123 	/* Disable writes through the rom window */
124 	pci_read_config_byte(window->pdev, BIOS_CNTL, &byte);
125 	pci_write_config_byte(window->pdev, BIOS_CNTL,
126 		byte & ~BIOS_WRITE_ENABLE);
127 
128 	/* Free all of the mtd devices */
129 	list_for_each_entry_safe(map, scratch, &window->maps, list) {
130 		if (map->rsrc.parent)
131 			release_resource(&map->rsrc);
132 		mtd_device_unregister(map->mtd);
133 		map_destroy(map->mtd);
134 		list_del(&map->list);
135 		kfree(map);
136 	}
137 	if (window->rsrc.parent)
138 		release_resource(&window->rsrc);
139 	if (window->virt) {
140 		iounmap(window->virt);
141 		window->virt = NULL;
142 		window->phys = 0;
143 		window->size = 0;
144 	}
145 	pci_dev_put(window->pdev);
146 }
147 
148 static int __init esb2rom_init_one(struct pci_dev *pdev,
149 				   const struct pci_device_id *ent)
150 {
151 	static char *rom_probe_types[] = { "cfi_probe", "jedec_probe", NULL };
152 	struct esb2rom_window *window = &esb2rom_window;
153 	struct esb2rom_map_info *map = NULL;
154 	unsigned long map_top;
155 	u8 byte;
156 	u16 word;
157 
158 	/* For now I just handle the ecb2 and I assume there
159 	 * are not a lot of resources up at the top of the address
160 	 * space.  It is possible to handle other devices in the
161 	 * top 16MiB but it is very painful.  Also since
162 	 * you can only really attach a FWH to an ICHX there
163 	 * a number of simplifications you can make.
164 	 *
165 	 * Also you can page firmware hubs if an 8MiB window isn't enough
166 	 * but don't currently handle that case either.
167 	 */
168 	window->pdev = pci_dev_get(pdev);
169 
170 	/* RLG:  experiment 2.  Force the window registers to the widest values */
171 
172 /*
173 	pci_read_config_word(pdev, FWH_DEC_EN1, &word);
174 	printk(KERN_DEBUG "Original FWH_DEC_EN1 : %x\n", word);
175 	pci_write_config_byte(pdev, FWH_DEC_EN1, 0xff);
176 	pci_read_config_byte(pdev, FWH_DEC_EN1, &byte);
177 	printk(KERN_DEBUG "New FWH_DEC_EN1 : %x\n", byte);
178 
179 	pci_read_config_byte(pdev, FWH_DEC_EN2, &byte);
180 	printk(KERN_DEBUG "Original FWH_DEC_EN2 : %x\n", byte);
181 	pci_write_config_byte(pdev, FWH_DEC_EN2, 0x0f);
182 	pci_read_config_byte(pdev, FWH_DEC_EN2, &byte);
183 	printk(KERN_DEBUG "New FWH_DEC_EN2 : %x\n", byte);
184 */
185 
186 	/* Find a region continuous to the end of the ROM window  */
187 	window->phys = 0;
188 	pci_read_config_word(pdev, FWH_DEC_EN1, &word);
189 	printk(KERN_DEBUG "pci_read_config_word : %x\n", word);
190 
191 	if ((word & FWH_8MiB) == FWH_8MiB)
192 		window->phys = 0xff400000;
193 	else if ((word & FWH_7MiB) == FWH_7MiB)
194 		window->phys = 0xff500000;
195 	else if ((word & FWH_6MiB) == FWH_6MiB)
196 		window->phys = 0xff600000;
197 	else if ((word & FWH_5MiB) == FWH_5MiB)
198 		window->phys = 0xFF700000;
199 	else if ((word & FWH_4MiB) == FWH_4MiB)
200 		window->phys = 0xffc00000;
201 	else if ((word & FWH_3_5MiB) == FWH_3_5MiB)
202 		window->phys = 0xffc80000;
203 	else if ((word & FWH_3MiB) == FWH_3MiB)
204 		window->phys = 0xffd00000;
205 	else if ((word & FWH_2_5MiB) == FWH_2_5MiB)
206 		window->phys = 0xffd80000;
207 	else if ((word & FWH_2MiB) == FWH_2MiB)
208 		window->phys = 0xffe00000;
209 	else if ((word & FWH_1_5MiB) == FWH_1_5MiB)
210 		window->phys = 0xffe80000;
211 	else if ((word & FWH_1MiB) == FWH_1MiB)
212 		window->phys = 0xfff00000;
213 	else if ((word & FWH_0_5MiB) == FWH_0_5MiB)
214 		window->phys = 0xfff80000;
215 
216 	if (window->phys == 0) {
217 		printk(KERN_ERR MOD_NAME ": Rom window is closed\n");
218 		goto out;
219 	}
220 
221 	/* reserved  0x0020 and 0x0010 */
222 	window->phys -= 0x400000UL;
223 	window->size = (0xffffffffUL - window->phys) + 1UL;
224 
225 	/* Enable writes through the rom window */
226 	pci_read_config_byte(pdev, BIOS_CNTL, &byte);
227 	if (!(byte & BIOS_WRITE_ENABLE)  && (byte & (BIOS_LOCK_ENABLE))) {
228 		/* The BIOS will generate an error if I enable
229 		 * this device, so don't even try.
230 		 */
231 		printk(KERN_ERR MOD_NAME ": firmware access control, I can't enable writes\n");
232 		goto out;
233 	}
234 	pci_write_config_byte(pdev, BIOS_CNTL, byte | BIOS_WRITE_ENABLE);
235 
236 	/*
237 	 * Try to reserve the window mem region.  If this fails then
238 	 * it is likely due to the window being "reserved" by the BIOS.
239 	 */
240 	window->rsrc.name = MOD_NAME;
241 	window->rsrc.start = window->phys;
242 	window->rsrc.end   = window->phys + window->size - 1;
243 	window->rsrc.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
244 	if (request_resource(&iomem_resource, &window->rsrc)) {
245 		window->rsrc.parent = NULL;
246 		printk(KERN_DEBUG MOD_NAME ": "
247 		       "%s(): Unable to register resource %pR - kernel bug?\n",
248 			__func__, &window->rsrc);
249 	}
250 
251 	/* Map the firmware hub into my address space. */
252 	window->virt = ioremap(window->phys, window->size);
253 	if (!window->virt) {
254 		printk(KERN_ERR MOD_NAME ": ioremap(%08lx, %08lx) failed\n",
255 			window->phys, window->size);
256 		goto out;
257 	}
258 
259 	/* Get the first address to look for an rom chip at */
260 	map_top = window->phys;
261 	if ((window->phys & 0x3fffff) != 0) {
262 		/* if not aligned on 4MiB, look 4MiB lower in address space */
263 		map_top = window->phys + 0x400000;
264 	}
265 #if 1
266 	/* The probe sequence run over the firmware hub lock
267 	 * registers sets them to 0x7 (no access).
268 	 * (Insane hardware design, but most copied Intel's.)
269 	 * ==> Probe at most the last 4M of the address space.
270 	 */
271 	if (map_top < 0xffc00000)
272 		map_top = 0xffc00000;
273 #endif
274 	/* Loop through and look for rom chips */
275 	while ((map_top - 1) < 0xffffffffUL) {
276 		struct cfi_private *cfi;
277 		unsigned long offset;
278 		int i;
279 
280 		if (!map)
281 			map = kmalloc(sizeof(*map), GFP_KERNEL);
282 		if (!map) {
283 			printk(KERN_ERR MOD_NAME ": kmalloc failed");
284 			goto out;
285 		}
286 		memset(map, 0, sizeof(*map));
287 		INIT_LIST_HEAD(&map->list);
288 		map->map.name = map->map_name;
289 		map->map.phys = map_top;
290 		offset = map_top - window->phys;
291 		map->map.virt = (void __iomem *)
292 			(((unsigned long)(window->virt)) + offset);
293 		map->map.size = 0xffffffffUL - map_top + 1UL;
294 		/* Set the name of the map to the address I am trying */
295 		sprintf(map->map_name, "%s @%08Lx",
296 			MOD_NAME, (unsigned long long)map->map.phys);
297 
298 		/* Firmware hubs only use vpp when being programmed
299 		 * in a factory setting.  So in-place programming
300 		 * needs to use a different method.
301 		 */
302 		for(map->map.bankwidth = 32; map->map.bankwidth;
303 			map->map.bankwidth >>= 1) {
304 			char **probe_type;
305 			/* Skip bankwidths that are not supported */
306 			if (!map_bankwidth_supported(map->map.bankwidth))
307 				continue;
308 
309 			/* Setup the map methods */
310 			simple_map_init(&map->map);
311 
312 			/* Try all of the probe methods */
313 			probe_type = rom_probe_types;
314 			for(; *probe_type; probe_type++) {
315 				map->mtd = do_map_probe(*probe_type, &map->map);
316 				if (map->mtd)
317 					goto found;
318 			}
319 		}
320 		map_top += ROM_PROBE_STEP_SIZE;
321 		continue;
322 	found:
323 		/* Trim the size if we are larger than the map */
324 		if (map->mtd->size > map->map.size) {
325 			printk(KERN_WARNING MOD_NAME
326 				" rom(%llu) larger than window(%lu). fixing...\n",
327 				(unsigned long long)map->mtd->size, map->map.size);
328 			map->mtd->size = map->map.size;
329 		}
330 		if (window->rsrc.parent) {
331 			/*
332 			 * Registering the MTD device in iomem may not be possible
333 			 * if there is a BIOS "reserved" and BUSY range.  If this
334 			 * fails then continue anyway.
335 			 */
336 			map->rsrc.name  = map->map_name;
337 			map->rsrc.start = map->map.phys;
338 			map->rsrc.end   = map->map.phys + map->mtd->size - 1;
339 			map->rsrc.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
340 			if (request_resource(&window->rsrc, &map->rsrc)) {
341 				printk(KERN_ERR MOD_NAME
342 					": cannot reserve MTD resource\n");
343 				map->rsrc.parent = NULL;
344 			}
345 		}
346 
347 		/* Make the whole region visible in the map */
348 		map->map.virt = window->virt;
349 		map->map.phys = window->phys;
350 		cfi = map->map.fldrv_priv;
351 		for(i = 0; i < cfi->numchips; i++)
352 			cfi->chips[i].start += offset;
353 
354 		/* Now that the mtd devices is complete claim and export it */
355 		map->mtd->owner = THIS_MODULE;
356 		if (mtd_device_register(map->mtd, NULL, 0)) {
357 			map_destroy(map->mtd);
358 			map->mtd = NULL;
359 			goto out;
360 		}
361 
362 		/* Calculate the new value of map_top */
363 		map_top += map->mtd->size;
364 
365 		/* File away the map structure */
366 		list_add(&map->list, &window->maps);
367 		map = NULL;
368 	}
369 
370  out:
371 	/* Free any left over map structures */
372 	kfree(map);
373 
374 	/* See if I have any map structures */
375 	if (list_empty(&window->maps)) {
376 		esb2rom_cleanup(window);
377 		return -ENODEV;
378 	}
379 	return 0;
380 }
381 
382 static void esb2rom_remove_one(struct pci_dev *pdev)
383 {
384 	struct esb2rom_window *window = &esb2rom_window;
385 	esb2rom_cleanup(window);
386 }
387 
388 static const struct pci_device_id esb2rom_pci_tbl[] = {
389 	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801BA_0,
390 	  PCI_ANY_ID, PCI_ANY_ID, },
391 	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801CA_0,
392 	  PCI_ANY_ID, PCI_ANY_ID, },
393 	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801DB_0,
394 	  PCI_ANY_ID, PCI_ANY_ID, },
395 	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801EB_0,
396 	  PCI_ANY_ID, PCI_ANY_ID, },
397 	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ESB_1,
398 	  PCI_ANY_ID, PCI_ANY_ID, },
399 	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ESB2_0,
400 	  PCI_ANY_ID, PCI_ANY_ID, },
401 	{ 0, },
402 };
403 
404 #if 0
405 MODULE_DEVICE_TABLE(pci, esb2rom_pci_tbl);
406 
407 static struct pci_driver esb2rom_driver = {
408 	.name =		MOD_NAME,
409 	.id_table =	esb2rom_pci_tbl,
410 	.probe =	esb2rom_init_one,
411 	.remove =	esb2rom_remove_one,
412 };
413 #endif
414 
415 static int __init init_esb2rom(void)
416 {
417 	struct pci_dev *pdev;
418 	const struct pci_device_id *id;
419 	int retVal;
420 
421 	pdev = NULL;
422 	for (id = esb2rom_pci_tbl; id->vendor; id++) {
423 		printk(KERN_DEBUG "device id = %x\n", id->device);
424 		pdev = pci_get_device(id->vendor, id->device, NULL);
425 		if (pdev) {
426 			printk(KERN_DEBUG "matched device = %x\n", id->device);
427 			break;
428 		}
429 	}
430 	if (pdev) {
431 		printk(KERN_DEBUG "matched device id %x\n", id->device);
432 		retVal = esb2rom_init_one(pdev, &esb2rom_pci_tbl[0]);
433 		pci_dev_put(pdev);
434 		printk(KERN_DEBUG "retVal = %d\n", retVal);
435 		return retVal;
436 	}
437 	return -ENXIO;
438 #if 0
439 	return pci_register_driver(&esb2rom_driver);
440 #endif
441 }
442 
443 static void __exit cleanup_esb2rom(void)
444 {
445 	esb2rom_remove_one(esb2rom_window.pdev);
446 }
447 
448 module_init(init_esb2rom);
449 module_exit(cleanup_esb2rom);
450 
451 MODULE_LICENSE("GPL");
452 MODULE_AUTHOR("Lew Glendenning <lglendenning@lnxi.com>");
453 MODULE_DESCRIPTION("MTD map driver for BIOS chips on the ESB2 southbridge");
454