summaryrefslogtreecommitdiffstats
path: root/drivers/char/watchdog/ibmasr.c
blob: 94155f6136c2369a10135cc62b9aef1896755d66 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
/*
 * IBM Automatic Server Restart driver.
 *
 * Copyright (c) 2005 Andrey Panin <pazke@donpac.ru>
 *
 * Based on driver written by Pete Reynolds.
 * Copyright (c) IBM Corporation, 1998-2004.
 *
 * This software may be used and distributed according to the terms
 * of the GNU Public License, incorporated herein by reference.
 */

#include <linux/fs.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/timer.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/dmi.h>

#include <asm/io.h>
#include <asm/uaccess.h>


enum {
	ASMTYPE_UNKNOWN,
	ASMTYPE_TOPAZ,
	ASMTYPE_JASPER,
	ASMTYPE_PEARL,
	ASMTYPE_JUNIPER,
	ASMTYPE_SPRUCE,
};

#define PFX "ibmasr: "

#define TOPAZ_ASR_REG_OFFSET	4
#define TOPAZ_ASR_TOGGLE	0x40
#define TOPAZ_ASR_DISABLE	0x80

/* PEARL ASR S/W REGISTER SUPERIO PORT ADDRESSES */
#define PEARL_BASE	0xe04
#define PEARL_WRITE	0xe06
#define PEARL_READ	0xe07

#define PEARL_ASR_DISABLE_MASK	0x80	/* bit 7: disable = 1, enable = 0 */
#define PEARL_ASR_TOGGLE_MASK	0x40	/* bit 6: 0, then 1, then 0 */

/* JASPER OFFSET FROM SIO BASE ADDR TO ASR S/W REGISTERS. */
#define JASPER_ASR_REG_OFFSET	0x38

#define JASPER_ASR_DISABLE_MASK	0x01	/* bit 0: disable = 1, enable = 0 */
#define JASPER_ASR_TOGGLE_MASK	0x02	/* bit 1: 0, then 1, then 0 */

#define JUNIPER_BASE_ADDRESS	0x54b	/* Base address of Juniper ASR */
#define JUNIPER_ASR_DISABLE_MASK 0x01	/* bit 0: disable = 1 enable = 0 */
#define JUNIPER_ASR_TOGGLE_MASK	0x02	/* bit 1: 0, then 1, then 0 */

#define SPRUCE_BASE_ADDRESS	0x118e	/* Base address of Spruce ASR */
#define SPRUCE_ASR_DISABLE_MASK	0x01	/* bit 1: disable = 1 enable = 0 */
#define SPRUCE_ASR_TOGGLE_MASK	0x02	/* bit 0: 0, then 1, then 0 */


static int nowayout = WATCHDOG_NOWAYOUT;

static unsigned long asr_is_open;
static char asr_expect_close;

static unsigned int asr_type, asr_base, asr_length;
static unsigned int asr_read_addr, asr_write_addr;
static unsigned char asr_toggle_mask, asr_disable_mask;

static void asr_toggle(void)
{
	unsigned char reg = inb(asr_read_addr);

	outb(reg & ~asr_toggle_mask, asr_write_addr);
	reg = inb(asr_read_addr);

	outb(reg | asr_toggle_mask, asr_write_addr);
	reg = inb(asr_read_addr);

	outb(reg & ~asr_toggle_mask, asr_write_addr);
	reg = inb(asr_read_addr);
}

static void asr_enable(void)
{
	unsigned char reg;

	if (asr_type == ASMTYPE_TOPAZ) {
		/* asr_write_addr == asr_read_addr */
		reg = inb(asr_read_addr);
		outb(reg & ~(TOPAZ_ASR_TOGGLE | TOPAZ_ASR_DISABLE),
		     asr_read_addr);
	} else {
		/*
		 * First make sure the hardware timer is reset by toggling
		 * ASR hardware timer line.
		 */
		asr_toggle();

		reg = inb(asr_read_addr);
		outb(reg & ~asr_disable_mask, asr_write_addr);
	}
	reg = inb(asr_read_addr);
}

static void asr_disable(void)
{
	unsigned char reg = inb(asr_read_addr);

	if (asr_type == ASMTYPE_TOPAZ)
		/* asr_write_addr == asr_read_addr */
		outb(reg | TOPAZ_ASR_TOGGLE | TOPAZ_ASR_DISABLE,
		     asr_read_addr);
	else {
		outb(reg | asr_toggle_mask, asr_write_addr);
		reg = inb(asr_read_addr);

		outb(reg | asr_disable_mask, asr_write_addr);
	}
	reg = inb(asr_read_addr);
}

static int __init asr_get_base_address(void)
{
	unsigned char low, high;
	const char *type = "";

	asr_length = 1;

	switch (asr_type) {
	case ASMTYPE_TOPAZ:
		/* SELECT SuperIO CHIP FOR QUERYING (WRITE 0x07 TO BOTH 0x2E and 0x2F) */
		outb(0x07, 0x2e);
		outb(0x07, 0x2f);

		/* SELECT AND READ THE HIGH-NIBBLE OF THE GPIO BASE ADDRESS */
		outb(0x60, 0x2e);
		high = inb(0x2f);

		/* SELECT AND READ THE LOW-NIBBLE OF THE GPIO BASE ADDRESS */
		outb(0x61, 0x2e);
		low = inb(0x2f);

		asr_base = (high << 16) | low;
		asr_read_addr = asr_write_addr =
			asr_base + TOPAZ_ASR_REG_OFFSET;
		asr_length = 5;

		break;

	case ASMTYPE_JASPER:
		type = "Jaspers ";

		/* FIXME: need to use pci_config_lock here, but it's not exported */

/*		spin_lock_irqsave(&pci_config_lock, flags);*/

		/* Select the SuperIO chip in the PCI I/O port register */
		outl(0x8000f858, 0xcf8);

		/*
		 * Read the base address for the SuperIO chip.
		 * Only the lower 16 bits are valid, but the address is word
		 * aligned so the last bit must be masked off.
		 */
		asr_base = inl(0xcfc) & 0xfffe;

/*		spin_unlock_irqrestore(&pci_config_lock, flags);*/

		asr_read_addr = asr_write_addr =
			asr_base + JASPER_ASR_REG_OFFSET;
		asr_toggle_mask = JASPER_ASR_TOGGLE_MASK;
		asr_disable_mask = JASPER_ASR_DISABLE_MASK;
		asr_length = JASPER_ASR_REG_OFFSET + 1;

		break;

	case ASMTYPE_PEARL:
		type = "Pearls ";
		asr_base = PEARL_BASE;
		asr_read_addr = PEARL_READ;
		asr_write_addr = PEARL_WRITE;
		asr_toggle_mask = PEARL_ASR_TOGGLE_MASK;
		asr_disable_mask = PEARL_ASR_DISABLE_MASK;
		asr_length = 4;
		break;

	case ASMTYPE_JUNIPER:
		type = "Junipers ";
		asr_base = JUNIPER_BASE_ADDRESS;
		asr_read_addr = asr_write_addr = asr_base;
		asr_toggle_mask = JUNIPER_ASR_TOGGLE_MASK;
		asr_disable_mask = JUNIPER_ASR_DISABLE_MASK;
		break;

	case ASMTYPE_SPRUCE:
		type = "Spruce's ";
		asr_base = SPRUCE_BASE_ADDRESS;
		asr_read_addr = asr_write_addr = asr_base;
		asr_toggle_mask = SPRUCE_ASR_TOGGLE_MASK;
		asr_disable_mask = SPRUCE_ASR_DISABLE_MASK;
		break;
	}

	if (!request_region(asr_base, asr_length, "ibmasr")) {
		printk(KERN_ERR PFX "address %#x already in use\n",
			asr_base);
		return -EBUSY;
	}

	printk(KERN_INFO PFX "found %sASR @ addr %#x\n", type, asr_base);

	return 0;
}


static ssize_t asr_write(struct file *file, const char __user *buf,
			 size_t count, loff_t *ppos)
{
	if (count) {
		if (!nowayout) {
			size_t i;

			/* In case it was set long ago */
			asr_expect_close = 0;

			for (i = 0; i != count; i++) {
				char c;
				if (get_user(c, buf + i))
					return -EFAULT;
				if (c == 'V')
					asr_expect_close = 42;
			}
		}
		asr_toggle();
	}
	return count;
}

static int asr_ioctl(struct inode *inode, struct file *file,
		     unsigned int cmd, unsigned long arg)
{
	static const struct watchdog_info ident = {
		.options =	WDIOF_KEEPALIVEPING | 
				WDIOF_MAGICCLOSE,
		.identity =	"IBM ASR"
	};
	void __user *argp = (void __user *)arg;
	int __user *p = argp;
	int heartbeat;

	switch (cmd) {
		case WDIOC_GETSUPPORT:
			return copy_to_user(argp, &ident, sizeof(ident)) ?
				-EFAULT : 0;

		case WDIOC_GETSTATUS:
		case WDIOC_GETBOOTSTATUS:
			return put_user(0, p);

		case WDIOC_KEEPALIVE:
			asr_toggle();
			return 0;

		/*
		 * The hardware has a fixed timeout value, so no WDIOC_SETTIMEOUT
		 * and WDIOC_GETTIMEOUT always returns 256.
		 */
		case WDIOC_GETTIMEOUT:
			heartbeat = 256;
			return put_user(heartbeat, p);

		case WDIOC_SETOPTIONS: {
			int new_options, retval = -EINVAL;

			if (get_user(new_options, p))
				return -EFAULT;

			if (new_options & WDIOS_DISABLECARD) {
				asr_disable();
				retval = 0;
			}

			if (new_options & WDIOS_ENABLECARD) {
				asr_enable();
				asr_toggle();
				retval = 0;
			}

			return retval;
		}
	}

	return -ENOTTY;
}

static int asr_open(struct inode *inode, struct file *file)
{
	if(test_and_set_bit(0, &asr_is_open))
		return -EBUSY;

	asr_toggle();
	asr_enable();

	return nonseekable_open(inode, file);
}

static int asr_release(struct inode *inode, struct file *file)
{
	if (asr_expect_close == 42)
		asr_disable();
	else {
		printk(KERN_CRIT PFX "unexpected close, not stopping watchdog!\n");
		asr_toggle();
	}
	clear_bit(0, &asr_is_open);
	asr_expect_close = 0;
	return 0;
}

static const struct file_operations asr_fops = {
	.owner =	THIS_MODULE,
	.llseek	=	no_llseek,
	.write =	asr_write,
	.ioctl =	asr_ioctl,
	.open =		asr_open,
	.release =	asr_release,
};

static struct miscdevice asr_miscdev = {
	.minor =	WATCHDOG_MINOR,
	.name =		"watchdog",
	.fops =		&asr_fops,
};


struct ibmasr_id {
	const char *desc;
	int type;
};

static struct ibmasr_id __initdata ibmasr_id_table[] = {
	{ "IBM Automatic Server Restart - eserver xSeries 220", ASMTYPE_TOPAZ },
	{ "IBM Automatic Server Restart - Machine Type 8673", ASMTYPE_PEARL },
	{ "IBM Automatic Server Restart - Machine Type 8480", ASMTYPE_JASPER },
	{ "IBM Automatic Server Restart - Machine Type 8482", ASMTYPE_JUNIPER },
	{ "IBM Automatic Server Restart - Machine Type 8648", ASMTYPE_SPRUCE },
	{ NULL }
};

static int __init ibmasr_init(void)
{
	struct ibmasr_id *id;
	int rc;

	for (id = ibmasr_id_table; id->desc; id++) {
		if (dmi_find_device(DMI_DEV_TYPE_OTHER, id->desc, NULL)) {
			asr_type = id->type;
			break;
		}
	}

	if (!asr_type)
		return -ENODEV;

	rc = asr_get_base_address();
	if (rc)
		return rc;

	rc = misc_register(&asr_miscdev);
	if (rc < 0) {
		release_region(asr_base, asr_length);
		printk(KERN_ERR PFX "failed to register misc device\n");
		return rc;
	}

	return 0;
}

static void __exit ibmasr_exit(void)
{
	if (!nowayout)
		asr_disable();

	misc_deregister(&asr_miscdev);

	release_region(asr_base, asr_length);
}

module_init(ibmasr_init);
module_exit(ibmasr_exit);

module_param(nowayout, int, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");

MODULE_DESCRIPTION("IBM Automatic Server Restart driver");
MODULE_AUTHOR("Andrey Panin");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
OpenPOWER on IntegriCloud