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
36struct 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
45struct 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
53static struct ichxrom_window ichxrom_window = {
54	.maps = LIST_HEAD_INIT(ichxrom_window.maps),
55};
56
57static 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
90static 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
321static void ichxrom_remove_one(struct pci_dev *pdev)
322{
323	struct ichxrom_window *window = &ichxrom_window;
324	ichxrom_cleanup(window);
325}
326
327static 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
342MODULE_DEVICE_TABLE(pci, ichxrom_pci_tbl);
343
344static 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
352static 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
373static void __exit cleanup_ichxrom(void)
374{
375	ichxrom_remove_one(ichxrom_window.pdev);
376}
377
378module_init(init_ichxrom);
379module_exit(cleanup_ichxrom);
380
381MODULE_LICENSE("GPL");
382MODULE_AUTHOR("Eric Biederman <ebiederman@lnxi.com>");
383MODULE_DESCRIPTION("MTD map driver for BIOS chips on the ICHX southbridge");
384