xref: /linux/drivers/watchdog/hpwdt.c (revision 79790b6818e96c58fe2bffee1b418c16e64e7b80)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *	HPE WatchDog Driver
4  *	based on
5  *
6  *	SoftDog	0.05:	A Software Watchdog Device
7  *
8  *	(c) Copyright 2018 Hewlett Packard Enterprise Development LP
9  *	Thomas Mingarelli <thomas.mingarelli@hpe.com>
10  */
11 
12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13 
14 #include <linux/device.h>
15 #include <linux/io.h>
16 #include <linux/kernel.h>
17 #include <linux/module.h>
18 #include <linux/moduleparam.h>
19 #include <linux/pci.h>
20 #include <linux/pci_ids.h>
21 #include <linux/types.h>
22 #include <linux/watchdog.h>
23 #ifdef CONFIG_HPWDT_NMI_DECODING
24 #include <asm/nmi.h>
25 #endif
26 #include <linux/crash_dump.h>
27 
28 #define HPWDT_VERSION			"2.0.4"
29 #define SECS_TO_TICKS(secs)		((secs) * 1000 / 128)
30 #define TICKS_TO_SECS(ticks)		((ticks) * 128 / 1000)
31 #define HPWDT_MAX_TICKS			65535
32 #define HPWDT_MAX_TIMER			TICKS_TO_SECS(HPWDT_MAX_TICKS)
33 #define DEFAULT_MARGIN			30
34 #define PRETIMEOUT_SEC			9
35 
36 static unsigned int soft_margin = DEFAULT_MARGIN;	/* in seconds */
37 static bool nowayout = WATCHDOG_NOWAYOUT;
38 static bool pretimeout = IS_ENABLED(CONFIG_HPWDT_NMI_DECODING);
39 static int kdumptimeout = -1;
40 
41 static void __iomem *pci_mem_addr;		/* the PCI-memory address */
42 static unsigned long __iomem *hpwdt_nmistat;
43 static unsigned long __iomem *hpwdt_timer_reg;
44 static unsigned long __iomem *hpwdt_timer_con;
45 
46 static const struct pci_device_id hpwdt_devices[] = {
47 	{ PCI_DEVICE(PCI_VENDOR_ID_COMPAQ, 0xB203) },	/* iLO2 */
48 	{ PCI_DEVICE(PCI_VENDOR_ID_HP, 0x3306) },	/* iLO3 */
49 	{ PCI_DEVICE(PCI_VENDOR_ID_HP_3PAR, 0x0389) },	/* PCtrl */
50 	{0},			/* terminate list */
51 };
52 MODULE_DEVICE_TABLE(pci, hpwdt_devices);
53 
54 static const struct pci_device_id hpwdt_blacklist[] = {
55 	{ PCI_DEVICE_SUB(PCI_VENDOR_ID_HP, 0x3306, PCI_VENDOR_ID_HP, 0x1979) }, /* auxilary iLO */
56 	{ PCI_DEVICE_SUB(PCI_VENDOR_ID_HP, 0x3306, PCI_VENDOR_ID_HP_3PAR, 0x0289) },  /* CL */
57 	{0},			/* terminate list */
58 };
59 
60 static struct watchdog_device hpwdt_dev;
61 /*
62  *	Watchdog operations
63  */
hpwdt_hw_is_running(void)64 static int hpwdt_hw_is_running(void)
65 {
66 	return ioread8(hpwdt_timer_con) & 0x01;
67 }
68 
hpwdt_start(struct watchdog_device * wdd)69 static int hpwdt_start(struct watchdog_device *wdd)
70 {
71 	int control = 0x81 | (pretimeout ? 0x4 : 0);
72 	int reload = SECS_TO_TICKS(min(wdd->timeout, wdd->max_hw_heartbeat_ms/1000));
73 
74 	dev_dbg(wdd->parent, "start watchdog 0x%08x:0x%08x:0x%02x\n", wdd->timeout, reload, control);
75 	iowrite16(reload, hpwdt_timer_reg);
76 	iowrite8(control, hpwdt_timer_con);
77 
78 	return 0;
79 }
80 
hpwdt_stop(void)81 static void hpwdt_stop(void)
82 {
83 	unsigned long data;
84 
85 	pr_debug("stop  watchdog\n");
86 
87 	data = ioread8(hpwdt_timer_con);
88 	data &= 0xFE;
89 	iowrite8(data, hpwdt_timer_con);
90 }
91 
hpwdt_stop_core(struct watchdog_device * wdd)92 static int hpwdt_stop_core(struct watchdog_device *wdd)
93 {
94 	hpwdt_stop();
95 
96 	return 0;
97 }
98 
hpwdt_ping_ticks(int val)99 static void hpwdt_ping_ticks(int val)
100 {
101 	val = min(val, HPWDT_MAX_TICKS);
102 	iowrite16(val, hpwdt_timer_reg);
103 }
104 
hpwdt_ping(struct watchdog_device * wdd)105 static int hpwdt_ping(struct watchdog_device *wdd)
106 {
107 	int reload = SECS_TO_TICKS(min(wdd->timeout, wdd->max_hw_heartbeat_ms/1000));
108 
109 	dev_dbg(wdd->parent, "ping  watchdog 0x%08x:0x%08x\n", wdd->timeout, reload);
110 	hpwdt_ping_ticks(reload);
111 
112 	return 0;
113 }
114 
hpwdt_gettimeleft(struct watchdog_device * wdd)115 static unsigned int hpwdt_gettimeleft(struct watchdog_device *wdd)
116 {
117 	return TICKS_TO_SECS(ioread16(hpwdt_timer_reg));
118 }
119 
hpwdt_settimeout(struct watchdog_device * wdd,unsigned int val)120 static int hpwdt_settimeout(struct watchdog_device *wdd, unsigned int val)
121 {
122 	dev_dbg(wdd->parent, "set_timeout = %d\n", val);
123 
124 	wdd->timeout = val;
125 	if (val <= wdd->pretimeout) {
126 		dev_dbg(wdd->parent, "pretimeout < timeout. Setting to zero\n");
127 		wdd->pretimeout = 0;
128 		pretimeout = false;
129 		if (watchdog_active(wdd))
130 			hpwdt_start(wdd);
131 	}
132 	hpwdt_ping(wdd);
133 
134 	return 0;
135 }
136 
137 #ifdef CONFIG_HPWDT_NMI_DECODING
hpwdt_set_pretimeout(struct watchdog_device * wdd,unsigned int req)138 static int hpwdt_set_pretimeout(struct watchdog_device *wdd, unsigned int req)
139 {
140 	unsigned int val = 0;
141 
142 	dev_dbg(wdd->parent, "set_pretimeout = %d\n", req);
143 	if (req) {
144 		val = PRETIMEOUT_SEC;
145 		if (val >= wdd->timeout)
146 			return -EINVAL;
147 	}
148 
149 	if (val != req)
150 		dev_dbg(wdd->parent, "Rounding pretimeout to: %d\n", val);
151 
152 	wdd->pretimeout = val;
153 	pretimeout = !!val;
154 
155 	if (watchdog_active(wdd))
156 		hpwdt_start(wdd);
157 
158 	return 0;
159 }
160 
hpwdt_my_nmi(void)161 static int hpwdt_my_nmi(void)
162 {
163 	return ioread8(hpwdt_nmistat) & 0x6;
164 }
165 
166 /*
167  *	NMI Handler
168  */
hpwdt_pretimeout(unsigned int ulReason,struct pt_regs * regs)169 static int hpwdt_pretimeout(unsigned int ulReason, struct pt_regs *regs)
170 {
171 	unsigned int mynmi = hpwdt_my_nmi();
172 	static char panic_msg[] =
173 		"00: An NMI occurred. Depending on your system the reason "
174 		"for the NMI is logged in any one of the following resources:\n"
175 		"1. Integrated Management Log (IML)\n"
176 		"2. OA Syslog\n"
177 		"3. OA Forward Progress Log\n"
178 		"4. iLO Event Log";
179 
180 	if (ulReason == NMI_UNKNOWN && !mynmi)
181 		return NMI_DONE;
182 
183 	if (kdumptimeout < 0)
184 		hpwdt_stop();
185 	else if (kdumptimeout == 0)
186 		;
187 	else {
188 		unsigned int val = max((unsigned int)kdumptimeout, hpwdt_dev.timeout);
189 		hpwdt_ping_ticks(SECS_TO_TICKS(val));
190 	}
191 
192 	hex_byte_pack(panic_msg, mynmi);
193 	nmi_panic(regs, panic_msg);
194 
195 	return NMI_HANDLED;
196 }
197 #endif /* CONFIG_HPWDT_NMI_DECODING */
198 
199 
200 static const struct watchdog_info ident = {
201 	.options = WDIOF_PRETIMEOUT    |
202 		   WDIOF_SETTIMEOUT    |
203 		   WDIOF_KEEPALIVEPING |
204 		   WDIOF_MAGICCLOSE,
205 	.identity = "HPE iLO2+ HW Watchdog Timer",
206 };
207 
208 /*
209  *	Kernel interfaces
210  */
211 
212 static const struct watchdog_ops hpwdt_ops = {
213 	.owner		= THIS_MODULE,
214 	.start		= hpwdt_start,
215 	.stop		= hpwdt_stop_core,
216 	.ping		= hpwdt_ping,
217 	.set_timeout	= hpwdt_settimeout,
218 	.get_timeleft	= hpwdt_gettimeleft,
219 #ifdef CONFIG_HPWDT_NMI_DECODING
220 	.set_pretimeout	= hpwdt_set_pretimeout,
221 #endif
222 };
223 
224 static struct watchdog_device hpwdt_dev = {
225 	.info		= &ident,
226 	.ops		= &hpwdt_ops,
227 	.min_timeout	= 1,
228 	.timeout	= DEFAULT_MARGIN,
229 	.pretimeout	= PRETIMEOUT_SEC,
230 	.max_hw_heartbeat_ms	= HPWDT_MAX_TIMER * 1000,
231 };
232 
233 
234 /*
235  *	Init & Exit
236  */
237 
hpwdt_init_nmi_decoding(struct pci_dev * dev)238 static int hpwdt_init_nmi_decoding(struct pci_dev *dev)
239 {
240 #ifdef CONFIG_HPWDT_NMI_DECODING
241 	int retval;
242 	/*
243 	 * Only one function can register for NMI_UNKNOWN
244 	 */
245 	retval = register_nmi_handler(NMI_UNKNOWN, hpwdt_pretimeout, 0, "hpwdt");
246 	if (retval)
247 		goto error;
248 	retval = register_nmi_handler(NMI_SERR, hpwdt_pretimeout, 0, "hpwdt");
249 	if (retval)
250 		goto error1;
251 	retval = register_nmi_handler(NMI_IO_CHECK, hpwdt_pretimeout, 0, "hpwdt");
252 	if (retval)
253 		goto error2;
254 
255 	dev_info(&dev->dev,
256 		"HPE Watchdog Timer Driver: NMI decoding initialized\n");
257 
258 	return 0;
259 
260 error2:
261 	unregister_nmi_handler(NMI_SERR, "hpwdt");
262 error1:
263 	unregister_nmi_handler(NMI_UNKNOWN, "hpwdt");
264 error:
265 	dev_warn(&dev->dev,
266 		"Unable to register a die notifier (err=%d).\n",
267 		retval);
268 	return retval;
269 #endif	/* CONFIG_HPWDT_NMI_DECODING */
270 	return 0;
271 }
272 
hpwdt_exit_nmi_decoding(void)273 static void hpwdt_exit_nmi_decoding(void)
274 {
275 #ifdef CONFIG_HPWDT_NMI_DECODING
276 	unregister_nmi_handler(NMI_UNKNOWN, "hpwdt");
277 	unregister_nmi_handler(NMI_SERR, "hpwdt");
278 	unregister_nmi_handler(NMI_IO_CHECK, "hpwdt");
279 #endif
280 }
281 
hpwdt_init_one(struct pci_dev * dev,const struct pci_device_id * ent)282 static int hpwdt_init_one(struct pci_dev *dev,
283 					const struct pci_device_id *ent)
284 {
285 	int retval;
286 
287 	/*
288 	 * First let's find out if we are on an iLO2+ server. We will
289 	 * not run on a legacy ASM box.
290 	 * So we only support the G5 ProLiant servers and higher.
291 	 */
292 	if (dev->subsystem_vendor != PCI_VENDOR_ID_HP &&
293 	    dev->subsystem_vendor != PCI_VENDOR_ID_HP_3PAR) {
294 		dev_warn(&dev->dev,
295 			"This server does not have an iLO2+ ASIC.\n");
296 		return -ENODEV;
297 	}
298 
299 	if (pci_match_id(hpwdt_blacklist, dev)) {
300 		dev_dbg(&dev->dev, "Not supported on this device\n");
301 		return -ENODEV;
302 	}
303 
304 	if (pci_enable_device(dev)) {
305 		dev_warn(&dev->dev,
306 			"Not possible to enable PCI Device: 0x%x:0x%x.\n",
307 			ent->vendor, ent->device);
308 		return -ENODEV;
309 	}
310 
311 	pci_mem_addr = pci_iomap(dev, 1, 0x80);
312 	if (!pci_mem_addr) {
313 		dev_warn(&dev->dev,
314 			"Unable to detect the iLO2+ server memory.\n");
315 		retval = -ENOMEM;
316 		goto error_pci_iomap;
317 	}
318 	hpwdt_nmistat	= pci_mem_addr + 0x6e;
319 	hpwdt_timer_reg = pci_mem_addr + 0x70;
320 	hpwdt_timer_con = pci_mem_addr + 0x72;
321 
322 	/* Have the core update running timer until user space is ready */
323 	if (hpwdt_hw_is_running()) {
324 		dev_info(&dev->dev, "timer is running\n");
325 		set_bit(WDOG_HW_RUNNING, &hpwdt_dev.status);
326 	}
327 
328 	/* Initialize NMI Decoding functionality */
329 	retval = hpwdt_init_nmi_decoding(dev);
330 	if (retval != 0)
331 		goto error_init_nmi_decoding;
332 
333 	watchdog_stop_on_unregister(&hpwdt_dev);
334 	watchdog_set_nowayout(&hpwdt_dev, nowayout);
335 	watchdog_init_timeout(&hpwdt_dev, soft_margin, NULL);
336 
337 	if (is_kdump_kernel()) {
338 		pretimeout = false;
339 		kdumptimeout = 0;
340 	}
341 
342 	if (pretimeout && hpwdt_dev.timeout <= PRETIMEOUT_SEC) {
343 		dev_warn(&dev->dev, "timeout <= pretimeout. Setting pretimeout to zero\n");
344 		pretimeout = false;
345 	}
346 	hpwdt_dev.pretimeout = pretimeout ? PRETIMEOUT_SEC : 0;
347 	kdumptimeout = min(kdumptimeout, HPWDT_MAX_TIMER);
348 
349 	hpwdt_dev.parent = &dev->dev;
350 	retval = watchdog_register_device(&hpwdt_dev);
351 	if (retval < 0)
352 		goto error_wd_register;
353 
354 	dev_info(&dev->dev, "HPE Watchdog Timer Driver: Version: %s\n",
355 				HPWDT_VERSION);
356 	dev_info(&dev->dev, "timeout: %d seconds (nowayout=%d)\n",
357 				hpwdt_dev.timeout, nowayout);
358 	dev_info(&dev->dev, "pretimeout: %s.\n",
359 				pretimeout ? "on" : "off");
360 	dev_info(&dev->dev, "kdumptimeout: %d.\n", kdumptimeout);
361 
362 	return 0;
363 
364 error_wd_register:
365 	hpwdt_exit_nmi_decoding();
366 error_init_nmi_decoding:
367 	pci_iounmap(dev, pci_mem_addr);
368 error_pci_iomap:
369 	pci_disable_device(dev);
370 	return retval;
371 }
372 
hpwdt_exit(struct pci_dev * dev)373 static void hpwdt_exit(struct pci_dev *dev)
374 {
375 	watchdog_unregister_device(&hpwdt_dev);
376 	hpwdt_exit_nmi_decoding();
377 	pci_iounmap(dev, pci_mem_addr);
378 	pci_disable_device(dev);
379 }
380 
hpwdt_suspend(struct device * dev)381 static int hpwdt_suspend(struct device *dev)
382 {
383 	if (watchdog_active(&hpwdt_dev))
384 		hpwdt_stop();
385 
386 	return 0;
387 }
388 
hpwdt_resume(struct device * dev)389 static int hpwdt_resume(struct device *dev)
390 {
391 	if (watchdog_active(&hpwdt_dev))
392 		hpwdt_start(&hpwdt_dev);
393 
394 	return 0;
395 }
396 
397 static const struct dev_pm_ops hpwdt_pm_ops = {
398 	LATE_SYSTEM_SLEEP_PM_OPS(hpwdt_suspend, hpwdt_resume)
399 };
400 
401 static struct pci_driver hpwdt_driver = {
402 	.name = "hpwdt",
403 	.id_table = hpwdt_devices,
404 	.probe = hpwdt_init_one,
405 	.remove = hpwdt_exit,
406 
407 	.driver = {
408 		.name = "hpwdt",
409 		.pm = &hpwdt_pm_ops,
410 	}
411 };
412 
413 MODULE_AUTHOR("Tom Mingarelli");
414 MODULE_DESCRIPTION("hpe watchdog driver");
415 MODULE_LICENSE("GPL");
416 MODULE_VERSION(HPWDT_VERSION);
417 
418 module_param(soft_margin, int, 0);
419 MODULE_PARM_DESC(soft_margin, "Watchdog timeout in seconds");
420 
421 module_param_named(timeout, soft_margin, int, 0);
422 MODULE_PARM_DESC(timeout, "Alias of soft_margin");
423 
424 module_param(nowayout, bool, 0);
425 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
426 		__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
427 
428 module_param(kdumptimeout, int, 0444);
429 MODULE_PARM_DESC(kdumptimeout, "Timeout applied for crash kernel transition in seconds");
430 
431 #ifdef CONFIG_HPWDT_NMI_DECODING
432 module_param(pretimeout, bool, 0);
433 MODULE_PARM_DESC(pretimeout, "Watchdog pretimeout enabled");
434 #endif
435 
436 module_pci_driver(hpwdt_driver);
437