xref: /openbmc/linux/drivers/watchdog/hpwdt.c (revision fe4549b1)
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 bool ilo5;
37 static unsigned int soft_margin = DEFAULT_MARGIN;	/* in seconds */
38 static bool nowayout = WATCHDOG_NOWAYOUT;
39 static bool pretimeout = IS_ENABLED(CONFIG_HPWDT_NMI_DECODING);
40 static int kdumptimeout = -1;
41 
42 static void __iomem *pci_mem_addr;		/* the PCI-memory address */
43 static unsigned long __iomem *hpwdt_nmistat;
44 static unsigned long __iomem *hpwdt_timer_reg;
45 static unsigned long __iomem *hpwdt_timer_con;
46 
47 static const struct pci_device_id hpwdt_devices[] = {
48 	{ PCI_DEVICE(PCI_VENDOR_ID_COMPAQ, 0xB203) },	/* iLO2 */
49 	{ PCI_DEVICE(PCI_VENDOR_ID_HP, 0x3306) },	/* iLO3 */
50 	{ PCI_DEVICE(PCI_VENDOR_ID_HP_3PAR, 0x0389) },	/* PCtrl */
51 	{0},			/* terminate list */
52 };
53 MODULE_DEVICE_TABLE(pci, hpwdt_devices);
54 
55 static const struct pci_device_id hpwdt_blacklist[] = {
56 	{ PCI_DEVICE_SUB(PCI_VENDOR_ID_HP, 0x3306, PCI_VENDOR_ID_HP, 0x1979) }, /* auxilary iLO */
57 	{ PCI_DEVICE_SUB(PCI_VENDOR_ID_HP, 0x3306, PCI_VENDOR_ID_HP_3PAR, 0x0289) },  /* CL */
58 	{0},			/* terminate list */
59 };
60 
61 static struct watchdog_device hpwdt_dev;
62 /*
63  *	Watchdog operations
64  */
65 static int hpwdt_hw_is_running(void)
66 {
67 	return ioread8(hpwdt_timer_con) & 0x01;
68 }
69 
70 static int hpwdt_start(struct watchdog_device *wdd)
71 {
72 	int control = 0x81 | (pretimeout ? 0x4 : 0);
73 	int reload = SECS_TO_TICKS(min(wdd->timeout, wdd->max_hw_heartbeat_ms/1000));
74 
75 	dev_dbg(wdd->parent, "start watchdog 0x%08x:0x%08x:0x%02x\n", wdd->timeout, reload, control);
76 	iowrite16(reload, hpwdt_timer_reg);
77 	iowrite8(control, hpwdt_timer_con);
78 
79 	return 0;
80 }
81 
82 static void hpwdt_stop(void)
83 {
84 	unsigned long data;
85 
86 	pr_debug("stop  watchdog\n");
87 
88 	data = ioread8(hpwdt_timer_con);
89 	data &= 0xFE;
90 	iowrite8(data, hpwdt_timer_con);
91 }
92 
93 static int hpwdt_stop_core(struct watchdog_device *wdd)
94 {
95 	hpwdt_stop();
96 
97 	return 0;
98 }
99 
100 static void hpwdt_ping_ticks(int val)
101 {
102 	val = min(val, HPWDT_MAX_TICKS);
103 	iowrite16(val, hpwdt_timer_reg);
104 }
105 
106 static int hpwdt_ping(struct watchdog_device *wdd)
107 {
108 	int reload = SECS_TO_TICKS(min(wdd->timeout, wdd->max_hw_heartbeat_ms/1000));
109 
110 	dev_dbg(wdd->parent, "ping  watchdog 0x%08x:0x%08x\n", wdd->timeout, reload);
111 	hpwdt_ping_ticks(reload);
112 
113 	return 0;
114 }
115 
116 static unsigned int hpwdt_gettimeleft(struct watchdog_device *wdd)
117 {
118 	return TICKS_TO_SECS(ioread16(hpwdt_timer_reg));
119 }
120 
121 static int hpwdt_settimeout(struct watchdog_device *wdd, unsigned int val)
122 {
123 	dev_dbg(wdd->parent, "set_timeout = %d\n", val);
124 
125 	wdd->timeout = val;
126 	if (val <= wdd->pretimeout) {
127 		dev_dbg(wdd->parent, "pretimeout < timeout. Setting to zero\n");
128 		wdd->pretimeout = 0;
129 		pretimeout = false;
130 		if (watchdog_active(wdd))
131 			hpwdt_start(wdd);
132 	}
133 	hpwdt_ping(wdd);
134 
135 	return 0;
136 }
137 
138 #ifdef CONFIG_HPWDT_NMI_DECODING
139 static int hpwdt_set_pretimeout(struct watchdog_device *wdd, unsigned int req)
140 {
141 	unsigned int val = 0;
142 
143 	dev_dbg(wdd->parent, "set_pretimeout = %d\n", req);
144 	if (req) {
145 		val = PRETIMEOUT_SEC;
146 		if (val >= wdd->timeout)
147 			return -EINVAL;
148 	}
149 
150 	if (val != req)
151 		dev_dbg(wdd->parent, "Rounding pretimeout to: %d\n", val);
152 
153 	wdd->pretimeout = val;
154 	pretimeout = !!val;
155 
156 	if (watchdog_active(wdd))
157 		hpwdt_start(wdd);
158 
159 	return 0;
160 }
161 
162 static int hpwdt_my_nmi(void)
163 {
164 	return ioread8(hpwdt_nmistat) & 0x6;
165 }
166 
167 /*
168  *	NMI Handler
169  */
170 static int hpwdt_pretimeout(unsigned int ulReason, struct pt_regs *regs)
171 {
172 	unsigned int mynmi = hpwdt_my_nmi();
173 	static char panic_msg[] =
174 		"00: An NMI occurred. Depending on your system the reason "
175 		"for the NMI is logged in any one of the following resources:\n"
176 		"1. Integrated Management Log (IML)\n"
177 		"2. OA Syslog\n"
178 		"3. OA Forward Progress Log\n"
179 		"4. iLO Event Log";
180 
181 	if (ulReason == NMI_UNKNOWN && !mynmi)
182 		return NMI_DONE;
183 
184 	if (ilo5 && !pretimeout && !mynmi)
185 		return NMI_DONE;
186 
187 	if (kdumptimeout < 0)
188 		hpwdt_stop();
189 	else if (kdumptimeout == 0)
190 		;
191 	else {
192 		unsigned int val = max((unsigned int)kdumptimeout, hpwdt_dev.timeout);
193 		hpwdt_ping_ticks(SECS_TO_TICKS(val));
194 	}
195 
196 	hex_byte_pack(panic_msg, mynmi);
197 	nmi_panic(regs, panic_msg);
198 
199 	return NMI_HANDLED;
200 }
201 #endif /* CONFIG_HPWDT_NMI_DECODING */
202 
203 
204 static const struct watchdog_info ident = {
205 	.options = WDIOF_PRETIMEOUT    |
206 		   WDIOF_SETTIMEOUT    |
207 		   WDIOF_KEEPALIVEPING |
208 		   WDIOF_MAGICCLOSE,
209 	.identity = "HPE iLO2+ HW Watchdog Timer",
210 };
211 
212 /*
213  *	Kernel interfaces
214  */
215 
216 static const struct watchdog_ops hpwdt_ops = {
217 	.owner		= THIS_MODULE,
218 	.start		= hpwdt_start,
219 	.stop		= hpwdt_stop_core,
220 	.ping		= hpwdt_ping,
221 	.set_timeout	= hpwdt_settimeout,
222 	.get_timeleft	= hpwdt_gettimeleft,
223 #ifdef CONFIG_HPWDT_NMI_DECODING
224 	.set_pretimeout	= hpwdt_set_pretimeout,
225 #endif
226 };
227 
228 static struct watchdog_device hpwdt_dev = {
229 	.info		= &ident,
230 	.ops		= &hpwdt_ops,
231 	.min_timeout	= 1,
232 	.timeout	= DEFAULT_MARGIN,
233 	.pretimeout	= PRETIMEOUT_SEC,
234 	.max_hw_heartbeat_ms	= HPWDT_MAX_TIMER * 1000,
235 };
236 
237 
238 /*
239  *	Init & Exit
240  */
241 
242 static int hpwdt_init_nmi_decoding(struct pci_dev *dev)
243 {
244 #ifdef CONFIG_HPWDT_NMI_DECODING
245 	int retval;
246 	/*
247 	 * Only one function can register for NMI_UNKNOWN
248 	 */
249 	retval = register_nmi_handler(NMI_UNKNOWN, hpwdt_pretimeout, 0, "hpwdt");
250 	if (retval)
251 		goto error;
252 	retval = register_nmi_handler(NMI_SERR, hpwdt_pretimeout, 0, "hpwdt");
253 	if (retval)
254 		goto error1;
255 	retval = register_nmi_handler(NMI_IO_CHECK, hpwdt_pretimeout, 0, "hpwdt");
256 	if (retval)
257 		goto error2;
258 
259 	dev_info(&dev->dev,
260 		"HPE Watchdog Timer Driver: NMI decoding initialized\n");
261 
262 	return 0;
263 
264 error2:
265 	unregister_nmi_handler(NMI_SERR, "hpwdt");
266 error1:
267 	unregister_nmi_handler(NMI_UNKNOWN, "hpwdt");
268 error:
269 	dev_warn(&dev->dev,
270 		"Unable to register a die notifier (err=%d).\n",
271 		retval);
272 	return retval;
273 #endif	/* CONFIG_HPWDT_NMI_DECODING */
274 	return 0;
275 }
276 
277 static void hpwdt_exit_nmi_decoding(void)
278 {
279 #ifdef CONFIG_HPWDT_NMI_DECODING
280 	unregister_nmi_handler(NMI_UNKNOWN, "hpwdt");
281 	unregister_nmi_handler(NMI_SERR, "hpwdt");
282 	unregister_nmi_handler(NMI_IO_CHECK, "hpwdt");
283 #endif
284 }
285 
286 static int hpwdt_init_one(struct pci_dev *dev,
287 					const struct pci_device_id *ent)
288 {
289 	int retval;
290 
291 	/*
292 	 * First let's find out if we are on an iLO2+ server. We will
293 	 * not run on a legacy ASM box.
294 	 * So we only support the G5 ProLiant servers and higher.
295 	 */
296 	if (dev->subsystem_vendor != PCI_VENDOR_ID_HP &&
297 	    dev->subsystem_vendor != PCI_VENDOR_ID_HP_3PAR) {
298 		dev_warn(&dev->dev,
299 			"This server does not have an iLO2+ ASIC.\n");
300 		return -ENODEV;
301 	}
302 
303 	if (pci_match_id(hpwdt_blacklist, dev)) {
304 		dev_dbg(&dev->dev, "Not supported on this device\n");
305 		return -ENODEV;
306 	}
307 
308 	if (pci_enable_device(dev)) {
309 		dev_warn(&dev->dev,
310 			"Not possible to enable PCI Device: 0x%x:0x%x.\n",
311 			ent->vendor, ent->device);
312 		return -ENODEV;
313 	}
314 
315 	pci_mem_addr = pci_iomap(dev, 1, 0x80);
316 	if (!pci_mem_addr) {
317 		dev_warn(&dev->dev,
318 			"Unable to detect the iLO2+ server memory.\n");
319 		retval = -ENOMEM;
320 		goto error_pci_iomap;
321 	}
322 	hpwdt_nmistat	= pci_mem_addr + 0x6e;
323 	hpwdt_timer_reg = pci_mem_addr + 0x70;
324 	hpwdt_timer_con = pci_mem_addr + 0x72;
325 
326 	/* Have the core update running timer until user space is ready */
327 	if (hpwdt_hw_is_running()) {
328 		dev_info(&dev->dev, "timer is running\n");
329 		set_bit(WDOG_HW_RUNNING, &hpwdt_dev.status);
330 	}
331 
332 	/* Initialize NMI Decoding functionality */
333 	retval = hpwdt_init_nmi_decoding(dev);
334 	if (retval != 0)
335 		goto error_init_nmi_decoding;
336 
337 	watchdog_stop_on_unregister(&hpwdt_dev);
338 	watchdog_set_nowayout(&hpwdt_dev, nowayout);
339 	watchdog_init_timeout(&hpwdt_dev, soft_margin, NULL);
340 
341 	if (is_kdump_kernel()) {
342 		pretimeout = false;
343 		kdumptimeout = 0;
344 	}
345 
346 	if (pretimeout && hpwdt_dev.timeout <= PRETIMEOUT_SEC) {
347 		dev_warn(&dev->dev, "timeout <= pretimeout. Setting pretimeout to zero\n");
348 		pretimeout = false;
349 	}
350 	hpwdt_dev.pretimeout = pretimeout ? PRETIMEOUT_SEC : 0;
351 	kdumptimeout = min(kdumptimeout, HPWDT_MAX_TIMER);
352 
353 	hpwdt_dev.parent = &dev->dev;
354 	retval = watchdog_register_device(&hpwdt_dev);
355 	if (retval < 0)
356 		goto error_wd_register;
357 
358 	dev_info(&dev->dev, "HPE Watchdog Timer Driver: Version: %s\n",
359 				HPWDT_VERSION);
360 	dev_info(&dev->dev, "timeout: %d seconds (nowayout=%d)\n",
361 				hpwdt_dev.timeout, nowayout);
362 	dev_info(&dev->dev, "pretimeout: %s.\n",
363 				pretimeout ? "on" : "off");
364 	dev_info(&dev->dev, "kdumptimeout: %d.\n", kdumptimeout);
365 
366 	if (dev->subsystem_vendor == PCI_VENDOR_ID_HP_3PAR)
367 		ilo5 = true;
368 
369 	return 0;
370 
371 error_wd_register:
372 	hpwdt_exit_nmi_decoding();
373 error_init_nmi_decoding:
374 	pci_iounmap(dev, pci_mem_addr);
375 error_pci_iomap:
376 	pci_disable_device(dev);
377 	return retval;
378 }
379 
380 static void hpwdt_exit(struct pci_dev *dev)
381 {
382 	watchdog_unregister_device(&hpwdt_dev);
383 	hpwdt_exit_nmi_decoding();
384 	pci_iounmap(dev, pci_mem_addr);
385 	pci_disable_device(dev);
386 }
387 
388 static struct pci_driver hpwdt_driver = {
389 	.name = "hpwdt",
390 	.id_table = hpwdt_devices,
391 	.probe = hpwdt_init_one,
392 	.remove = hpwdt_exit,
393 };
394 
395 MODULE_AUTHOR("Tom Mingarelli");
396 MODULE_DESCRIPTION("hpe watchdog driver");
397 MODULE_LICENSE("GPL");
398 MODULE_VERSION(HPWDT_VERSION);
399 
400 module_param(soft_margin, int, 0);
401 MODULE_PARM_DESC(soft_margin, "Watchdog timeout in seconds");
402 
403 module_param_named(timeout, soft_margin, int, 0);
404 MODULE_PARM_DESC(timeout, "Alias of soft_margin");
405 
406 module_param(nowayout, bool, 0);
407 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
408 		__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
409 
410 module_param(kdumptimeout, int, 0444);
411 MODULE_PARM_DESC(kdumptimeout, "Timeout applied for crash kernel transition in seconds");
412 
413 #ifdef CONFIG_HPWDT_NMI_DECODING
414 module_param(pretimeout, bool, 0);
415 MODULE_PARM_DESC(pretimeout, "Watchdog pretimeout enabled");
416 #endif
417 
418 module_pci_driver(hpwdt_driver);
419