xref: /linux/drivers/watchdog/ibmasr.c (revision 7ca26efb09a1543fddb29308ea3b63b66cb5d3ee)
1 // SPDX-License-Identifier: GPL-1.0+
2 /*
3  * IBM Automatic Server Restart driver.
4  *
5  * Copyright (c) 2005 Andrey Panin <pazke@donpac.ru>
6  *
7  * Based on driver written by Pete Reynolds.
8  * Copyright (c) IBM Corporation, 1998-2004.
9  *
10  */
11 
12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13 
14 #include <linux/fs.h>
15 #include <linux/kernel.h>
16 #include <linux/module.h>
17 #include <linux/pci.h>
18 #include <linux/timer.h>
19 #include <linux/miscdevice.h>
20 #include <linux/watchdog.h>
21 #include <linux/dmi.h>
22 #include <linux/io.h>
23 #include <linux/uaccess.h>
24 
25 
26 enum {
27 	ASMTYPE_UNKNOWN,
28 	ASMTYPE_TOPAZ,
29 	ASMTYPE_JASPER,
30 	ASMTYPE_PEARL,
31 	ASMTYPE_JUNIPER,
32 	ASMTYPE_SPRUCE,
33 };
34 
35 #define TOPAZ_ASR_REG_OFFSET	4
36 #define TOPAZ_ASR_TOGGLE	0x40
37 #define TOPAZ_ASR_DISABLE	0x80
38 
39 /* PEARL ASR S/W REGISTER SUPERIO PORT ADDRESSES */
40 #define PEARL_BASE	0xe04
41 #define PEARL_WRITE	0xe06
42 #define PEARL_READ	0xe07
43 
44 #define PEARL_ASR_DISABLE_MASK	0x80	/* bit 7: disable = 1, enable = 0 */
45 #define PEARL_ASR_TOGGLE_MASK	0x40	/* bit 6: 0, then 1, then 0 */
46 
47 /* JASPER OFFSET FROM SIO BASE ADDR TO ASR S/W REGISTERS. */
48 #define JASPER_ASR_REG_OFFSET	0x38
49 
50 #define JASPER_ASR_DISABLE_MASK	0x01	/* bit 0: disable = 1, enable = 0 */
51 #define JASPER_ASR_TOGGLE_MASK	0x02	/* bit 1: 0, then 1, then 0 */
52 
53 #define JUNIPER_BASE_ADDRESS	0x54b	/* Base address of Juniper ASR */
54 #define JUNIPER_ASR_DISABLE_MASK 0x01	/* bit 0: disable = 1 enable = 0 */
55 #define JUNIPER_ASR_TOGGLE_MASK	0x02	/* bit 1: 0, then 1, then 0 */
56 
57 #define SPRUCE_BASE_ADDRESS	0x118e	/* Base address of Spruce ASR */
58 #define SPRUCE_ASR_DISABLE_MASK	0x01	/* bit 1: disable = 1 enable = 0 */
59 #define SPRUCE_ASR_TOGGLE_MASK	0x02	/* bit 0: 0, then 1, then 0 */
60 
61 
62 static bool nowayout = WATCHDOG_NOWAYOUT;
63 
64 static unsigned long asr_is_open;
65 static char asr_expect_close;
66 
67 static unsigned int asr_type, asr_base, asr_length;
68 static unsigned int asr_read_addr, asr_write_addr;
69 static unsigned char asr_toggle_mask, asr_disable_mask;
70 static DEFINE_SPINLOCK(asr_lock);
71 
72 static void __asr_toggle(void)
73 {
74 	unsigned char reg;
75 
76 	reg = inb(asr_read_addr);
77 
78 	outb(reg & ~asr_toggle_mask, asr_write_addr);
79 	reg = inb(asr_read_addr);
80 
81 	outb(reg | asr_toggle_mask, asr_write_addr);
82 	reg = inb(asr_read_addr);
83 
84 	outb(reg & ~asr_toggle_mask, asr_write_addr);
85 	reg = inb(asr_read_addr);
86 }
87 
88 static void asr_toggle(void)
89 {
90 	spin_lock(&asr_lock);
91 	__asr_toggle();
92 	spin_unlock(&asr_lock);
93 }
94 
95 static void asr_enable(void)
96 {
97 	unsigned char reg;
98 
99 	spin_lock(&asr_lock);
100 	if (asr_type == ASMTYPE_TOPAZ) {
101 		/* asr_write_addr == asr_read_addr */
102 		reg = inb(asr_read_addr);
103 		outb(reg & ~(TOPAZ_ASR_TOGGLE | TOPAZ_ASR_DISABLE),
104 		     asr_read_addr);
105 	} else {
106 		/*
107 		 * First make sure the hardware timer is reset by toggling
108 		 * ASR hardware timer line.
109 		 */
110 		__asr_toggle();
111 
112 		reg = inb(asr_read_addr);
113 		outb(reg & ~asr_disable_mask, asr_write_addr);
114 	}
115 	reg = inb(asr_read_addr);
116 	spin_unlock(&asr_lock);
117 }
118 
119 static void asr_disable(void)
120 {
121 	unsigned char reg;
122 
123 	spin_lock(&asr_lock);
124 	reg = inb(asr_read_addr);
125 
126 	if (asr_type == ASMTYPE_TOPAZ)
127 		/* asr_write_addr == asr_read_addr */
128 		outb(reg | TOPAZ_ASR_TOGGLE | TOPAZ_ASR_DISABLE,
129 		     asr_read_addr);
130 	else {
131 		outb(reg | asr_toggle_mask, asr_write_addr);
132 		reg = inb(asr_read_addr);
133 
134 		outb(reg | asr_disable_mask, asr_write_addr);
135 	}
136 	reg = inb(asr_read_addr);
137 	spin_unlock(&asr_lock);
138 }
139 
140 static int __init asr_get_base_address(void)
141 {
142 	unsigned char low, high;
143 	const char *type = "";
144 
145 	asr_length = 1;
146 
147 	switch (asr_type) {
148 	case ASMTYPE_TOPAZ:
149 		/* SELECT SuperIO CHIP FOR QUERYING
150 		   (WRITE 0x07 TO BOTH 0x2E and 0x2F) */
151 		outb(0x07, 0x2e);
152 		outb(0x07, 0x2f);
153 
154 		/* SELECT AND READ THE HIGH-NIBBLE OF THE GPIO BASE ADDRESS */
155 		outb(0x60, 0x2e);
156 		high = inb(0x2f);
157 
158 		/* SELECT AND READ THE LOW-NIBBLE OF THE GPIO BASE ADDRESS */
159 		outb(0x61, 0x2e);
160 		low = inb(0x2f);
161 
162 		asr_base = (high << 16) | low;
163 		asr_read_addr = asr_write_addr =
164 			asr_base + TOPAZ_ASR_REG_OFFSET;
165 		asr_length = 5;
166 
167 		break;
168 
169 	case ASMTYPE_JASPER:
170 		type = "Jaspers ";
171 #if 0
172 		u32 r;
173 		/* Suggested fix */
174 		pdev = pci_get_bus_and_slot(0, DEVFN(0x1f, 0));
175 		if (pdev == NULL)
176 			return -ENODEV;
177 		pci_read_config_dword(pdev, 0x58, &r);
178 		asr_base = r & 0xFFFE;
179 		pci_dev_put(pdev);
180 #else
181 		/* FIXME: need to use pci_config_lock here,
182 		   but it's not exported */
183 
184 /*		spin_lock_irqsave(&pci_config_lock, flags);*/
185 
186 		/* Select the SuperIO chip in the PCI I/O port register */
187 		outl(0x8000f858, 0xcf8);
188 
189 		/* BUS 0, Slot 1F, fnc 0, offset 58 */
190 
191 		/*
192 		 * Read the base address for the SuperIO chip.
193 		 * Only the lower 16 bits are valid, but the address is word
194 		 * aligned so the last bit must be masked off.
195 		 */
196 		asr_base = inl(0xcfc) & 0xfffe;
197 
198 /*		spin_unlock_irqrestore(&pci_config_lock, flags);*/
199 #endif
200 		asr_read_addr = asr_write_addr =
201 			asr_base + JASPER_ASR_REG_OFFSET;
202 		asr_toggle_mask = JASPER_ASR_TOGGLE_MASK;
203 		asr_disable_mask = JASPER_ASR_DISABLE_MASK;
204 		asr_length = JASPER_ASR_REG_OFFSET + 1;
205 
206 		break;
207 
208 	case ASMTYPE_PEARL:
209 		type = "Pearls ";
210 		asr_base = PEARL_BASE;
211 		asr_read_addr = PEARL_READ;
212 		asr_write_addr = PEARL_WRITE;
213 		asr_toggle_mask = PEARL_ASR_TOGGLE_MASK;
214 		asr_disable_mask = PEARL_ASR_DISABLE_MASK;
215 		asr_length = 4;
216 		break;
217 
218 	case ASMTYPE_JUNIPER:
219 		type = "Junipers ";
220 		asr_base = JUNIPER_BASE_ADDRESS;
221 		asr_read_addr = asr_write_addr = asr_base;
222 		asr_toggle_mask = JUNIPER_ASR_TOGGLE_MASK;
223 		asr_disable_mask = JUNIPER_ASR_DISABLE_MASK;
224 		break;
225 
226 	case ASMTYPE_SPRUCE:
227 		type = "Spruce's ";
228 		asr_base = SPRUCE_BASE_ADDRESS;
229 		asr_read_addr = asr_write_addr = asr_base;
230 		asr_toggle_mask = SPRUCE_ASR_TOGGLE_MASK;
231 		asr_disable_mask = SPRUCE_ASR_DISABLE_MASK;
232 		break;
233 	}
234 
235 	if (!request_region(asr_base, asr_length, "ibmasr")) {
236 		pr_err("address %#x already in use\n", asr_base);
237 		return -EBUSY;
238 	}
239 
240 	pr_info("found %sASR @ addr %#x\n", type, asr_base);
241 
242 	return 0;
243 }
244 
245 
246 static ssize_t asr_write(struct file *file, const char __user *buf,
247 			 size_t count, loff_t *ppos)
248 {
249 	if (count) {
250 		if (!nowayout) {
251 			size_t i;
252 
253 			/* In case it was set long ago */
254 			asr_expect_close = 0;
255 
256 			for (i = 0; i != count; i++) {
257 				char c;
258 				if (get_user(c, buf + i))
259 					return -EFAULT;
260 				if (c == 'V')
261 					asr_expect_close = 42;
262 			}
263 		}
264 		asr_toggle();
265 	}
266 	return count;
267 }
268 
269 static long asr_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
270 {
271 	static const struct watchdog_info ident = {
272 		.options =	WDIOF_KEEPALIVEPING |
273 				WDIOF_MAGICCLOSE,
274 		.identity =	"IBM ASR",
275 	};
276 	void __user *argp = (void __user *)arg;
277 	int __user *p = argp;
278 	int heartbeat;
279 
280 	switch (cmd) {
281 	case WDIOC_GETSUPPORT:
282 		return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
283 	case WDIOC_GETSTATUS:
284 	case WDIOC_GETBOOTSTATUS:
285 		return put_user(0, p);
286 	case WDIOC_SETOPTIONS:
287 	{
288 		int new_options, retval = -EINVAL;
289 		if (get_user(new_options, p))
290 			return -EFAULT;
291 		if (new_options & WDIOS_DISABLECARD) {
292 			asr_disable();
293 			retval = 0;
294 		}
295 		if (new_options & WDIOS_ENABLECARD) {
296 			asr_enable();
297 			asr_toggle();
298 			retval = 0;
299 		}
300 		return retval;
301 	}
302 	case WDIOC_KEEPALIVE:
303 		asr_toggle();
304 		return 0;
305 	/*
306 	 * The hardware has a fixed timeout value, so no WDIOC_SETTIMEOUT
307 	 * and WDIOC_GETTIMEOUT always returns 256.
308 	 */
309 	case WDIOC_GETTIMEOUT:
310 		heartbeat = 256;
311 		return put_user(heartbeat, p);
312 	default:
313 		return -ENOTTY;
314 	}
315 }
316 
317 static int asr_open(struct inode *inode, struct file *file)
318 {
319 	if (test_and_set_bit(0, &asr_is_open))
320 		return -EBUSY;
321 
322 	asr_toggle();
323 	asr_enable();
324 
325 	return stream_open(inode, file);
326 }
327 
328 static int asr_release(struct inode *inode, struct file *file)
329 {
330 	if (asr_expect_close == 42)
331 		asr_disable();
332 	else {
333 		pr_crit("unexpected close, not stopping watchdog!\n");
334 		asr_toggle();
335 	}
336 	clear_bit(0, &asr_is_open);
337 	asr_expect_close = 0;
338 	return 0;
339 }
340 
341 static const struct file_operations asr_fops = {
342 	.owner =		THIS_MODULE,
343 	.llseek =		no_llseek,
344 	.write =		asr_write,
345 	.unlocked_ioctl =	asr_ioctl,
346 	.compat_ioctl =		compat_ptr_ioctl,
347 	.open =			asr_open,
348 	.release =		asr_release,
349 };
350 
351 static struct miscdevice asr_miscdev = {
352 	.minor =	WATCHDOG_MINOR,
353 	.name =		"watchdog",
354 	.fops =		&asr_fops,
355 };
356 
357 
358 struct ibmasr_id {
359 	const char *desc;
360 	int type;
361 };
362 
363 static struct ibmasr_id ibmasr_id_table[] __initdata = {
364 	{ "IBM Automatic Server Restart - eserver xSeries 220", ASMTYPE_TOPAZ },
365 	{ "IBM Automatic Server Restart - Machine Type 8673", ASMTYPE_PEARL },
366 	{ "IBM Automatic Server Restart - Machine Type 8480", ASMTYPE_JASPER },
367 	{ "IBM Automatic Server Restart - Machine Type 8482", ASMTYPE_JUNIPER },
368 	{ "IBM Automatic Server Restart - Machine Type 8648", ASMTYPE_SPRUCE },
369 	{ NULL }
370 };
371 
372 static int __init ibmasr_init(void)
373 {
374 	struct ibmasr_id *id;
375 	int rc;
376 
377 	for (id = ibmasr_id_table; id->desc; id++) {
378 		if (dmi_find_device(DMI_DEV_TYPE_OTHER, id->desc, NULL)) {
379 			asr_type = id->type;
380 			break;
381 		}
382 	}
383 
384 	if (!asr_type)
385 		return -ENODEV;
386 
387 	rc = asr_get_base_address();
388 	if (rc)
389 		return rc;
390 
391 	rc = misc_register(&asr_miscdev);
392 	if (rc < 0) {
393 		release_region(asr_base, asr_length);
394 		pr_err("failed to register misc device\n");
395 		return rc;
396 	}
397 
398 	return 0;
399 }
400 
401 static void __exit ibmasr_exit(void)
402 {
403 	if (!nowayout)
404 		asr_disable();
405 
406 	misc_deregister(&asr_miscdev);
407 
408 	release_region(asr_base, asr_length);
409 }
410 
411 module_init(ibmasr_init);
412 module_exit(ibmasr_exit);
413 
414 module_param(nowayout, bool, 0);
415 MODULE_PARM_DESC(nowayout,
416 	"Watchdog cannot be stopped once started (default="
417 				__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
418 
419 MODULE_DESCRIPTION("IBM Automatic Server Restart driver");
420 MODULE_AUTHOR("Andrey Panin");
421 MODULE_LICENSE("GPL");
422