xref: /openbmc/linux/drivers/watchdog/hpwdt.c (revision 249592bf)
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 #include <asm/nmi.h>
24 #include <linux/crash_dump.h>
25 
26 #define HPWDT_VERSION			"2.0.4"
27 #define SECS_TO_TICKS(secs)		((secs) * 1000 / 128)
28 #define TICKS_TO_SECS(ticks)		((ticks) * 128 / 1000)
29 #define HPWDT_MAX_TICKS			65535
30 #define HPWDT_MAX_TIMER			TICKS_TO_SECS(HPWDT_MAX_TICKS)
31 #define DEFAULT_MARGIN			30
32 #define PRETIMEOUT_SEC			9
33 
34 static bool ilo5;
35 static unsigned int soft_margin = DEFAULT_MARGIN;	/* in seconds */
36 static bool nowayout = WATCHDOG_NOWAYOUT;
37 static bool pretimeout = IS_ENABLED(CONFIG_HPWDT_NMI_DECODING);
38 static int kdumptimeout = -1;
39 
40 static void __iomem *pci_mem_addr;		/* the PCI-memory address */
41 static unsigned long __iomem *hpwdt_nmistat;
42 static unsigned long __iomem *hpwdt_timer_reg;
43 static unsigned long __iomem *hpwdt_timer_con;
44 
45 static const struct pci_device_id hpwdt_devices[] = {
46 	{ PCI_DEVICE(PCI_VENDOR_ID_COMPAQ, 0xB203) },	/* iLO2 */
47 	{ PCI_DEVICE(PCI_VENDOR_ID_HP, 0x3306) },	/* iLO3 */
48 	{0},			/* terminate list */
49 };
50 MODULE_DEVICE_TABLE(pci, hpwdt_devices);
51 
52 static const struct pci_device_id hpwdt_blacklist[] = {
53 	{ PCI_DEVICE_SUB(PCI_VENDOR_ID_HP, 0x3306, PCI_VENDOR_ID_HP, 0x1979) }, /* auxilary iLO */
54 	{ PCI_DEVICE_SUB(PCI_VENDOR_ID_HP, 0x3306, PCI_VENDOR_ID_HP_3PAR, 0x0289) },  /* CL */
55 	{0},			/* terminate list */
56 };
57 
58 static struct watchdog_device hpwdt_dev;
59 /*
60  *	Watchdog operations
61  */
62 static int hpwdt_hw_is_running(void)
63 {
64 	return ioread8(hpwdt_timer_con) & 0x01;
65 }
66 
67 static int hpwdt_start(struct watchdog_device *wdd)
68 {
69 	int control = 0x81 | (pretimeout ? 0x4 : 0);
70 	int reload = SECS_TO_TICKS(min(wdd->timeout, wdd->max_hw_heartbeat_ms/1000));
71 
72 	dev_dbg(wdd->parent, "start watchdog 0x%08x:0x%08x:0x%02x\n", wdd->timeout, reload, control);
73 	iowrite16(reload, hpwdt_timer_reg);
74 	iowrite8(control, hpwdt_timer_con);
75 
76 	return 0;
77 }
78 
79 static void hpwdt_stop(void)
80 {
81 	unsigned long data;
82 
83 	pr_debug("stop  watchdog\n");
84 
85 	data = ioread8(hpwdt_timer_con);
86 	data &= 0xFE;
87 	iowrite8(data, hpwdt_timer_con);
88 }
89 
90 static int hpwdt_stop_core(struct watchdog_device *wdd)
91 {
92 	hpwdt_stop();
93 
94 	return 0;
95 }
96 
97 static void hpwdt_ping_ticks(int val)
98 {
99 	val = min(val, HPWDT_MAX_TICKS);
100 	iowrite16(val, hpwdt_timer_reg);
101 }
102 
103 static int hpwdt_ping(struct watchdog_device *wdd)
104 {
105 	int reload = SECS_TO_TICKS(min(wdd->timeout, wdd->max_hw_heartbeat_ms/1000));
106 
107 	dev_dbg(wdd->parent, "ping  watchdog 0x%08x:0x%08x\n", wdd->timeout, reload);
108 	hpwdt_ping_ticks(reload);
109 
110 	return 0;
111 }
112 
113 static unsigned int hpwdt_gettimeleft(struct watchdog_device *wdd)
114 {
115 	return TICKS_TO_SECS(ioread16(hpwdt_timer_reg));
116 }
117 
118 static int hpwdt_settimeout(struct watchdog_device *wdd, unsigned int val)
119 {
120 	dev_dbg(wdd->parent, "set_timeout = %d\n", val);
121 
122 	wdd->timeout = val;
123 	if (val <= wdd->pretimeout) {
124 		dev_dbg(wdd->parent, "pretimeout < timeout. Setting to zero\n");
125 		wdd->pretimeout = 0;
126 		pretimeout = false;
127 		if (watchdog_active(wdd))
128 			hpwdt_start(wdd);
129 	}
130 	hpwdt_ping(wdd);
131 
132 	return 0;
133 }
134 
135 #ifdef CONFIG_HPWDT_NMI_DECODING
136 static int hpwdt_set_pretimeout(struct watchdog_device *wdd, unsigned int req)
137 {
138 	unsigned int val = 0;
139 
140 	dev_dbg(wdd->parent, "set_pretimeout = %d\n", req);
141 	if (req) {
142 		val = PRETIMEOUT_SEC;
143 		if (val >= wdd->timeout)
144 			return -EINVAL;
145 	}
146 
147 	if (val != req)
148 		dev_dbg(wdd->parent, "Rounding pretimeout to: %d\n", val);
149 
150 	wdd->pretimeout = val;
151 	pretimeout = !!val;
152 
153 	if (watchdog_active(wdd))
154 		hpwdt_start(wdd);
155 
156 	return 0;
157 }
158 
159 static int hpwdt_my_nmi(void)
160 {
161 	return ioread8(hpwdt_nmistat) & 0x6;
162 }
163 
164 /*
165  *	NMI Handler
166  */
167 static int hpwdt_pretimeout(unsigned int ulReason, struct pt_regs *regs)
168 {
169 	unsigned int mynmi = hpwdt_my_nmi();
170 	static char panic_msg[] =
171 		"00: An NMI occurred. Depending on your system the reason "
172 		"for the NMI is logged in any one of the following resources:\n"
173 		"1. Integrated Management Log (IML)\n"
174 		"2. OA Syslog\n"
175 		"3. OA Forward Progress Log\n"
176 		"4. iLO Event Log";
177 
178 	if (ilo5 && ulReason == NMI_UNKNOWN && !mynmi)
179 		return NMI_DONE;
180 
181 	if (ilo5 && !pretimeout && !mynmi)
182 		return NMI_DONE;
183 
184 	if (kdumptimeout < 0)
185 		hpwdt_stop();
186 	else if (kdumptimeout == 0)
187 		;
188 	else {
189 		unsigned int val = max((unsigned int)kdumptimeout, hpwdt_dev.timeout);
190 		hpwdt_ping_ticks(SECS_TO_TICKS(val));
191 	}
192 
193 	hex_byte_pack(panic_msg, mynmi);
194 	nmi_panic(regs, panic_msg);
195 
196 	return NMI_HANDLED;
197 }
198 #endif /* CONFIG_HPWDT_NMI_DECODING */
199 
200 
201 static const struct watchdog_info ident = {
202 	.options = WDIOF_PRETIMEOUT    |
203 		   WDIOF_SETTIMEOUT    |
204 		   WDIOF_KEEPALIVEPING |
205 		   WDIOF_MAGICCLOSE,
206 	.identity = "HPE iLO2+ HW Watchdog Timer",
207 };
208 
209 /*
210  *	Kernel interfaces
211  */
212 
213 static const struct watchdog_ops hpwdt_ops = {
214 	.owner		= THIS_MODULE,
215 	.start		= hpwdt_start,
216 	.stop		= hpwdt_stop_core,
217 	.ping		= hpwdt_ping,
218 	.set_timeout	= hpwdt_settimeout,
219 	.get_timeleft	= hpwdt_gettimeleft,
220 #ifdef CONFIG_HPWDT_NMI_DECODING
221 	.set_pretimeout	= hpwdt_set_pretimeout,
222 #endif
223 };
224 
225 static struct watchdog_device hpwdt_dev = {
226 	.info		= &ident,
227 	.ops		= &hpwdt_ops,
228 	.min_timeout	= 1,
229 	.timeout	= DEFAULT_MARGIN,
230 	.pretimeout	= PRETIMEOUT_SEC,
231 	.max_hw_heartbeat_ms	= HPWDT_MAX_TIMER * 1000,
232 };
233 
234 
235 /*
236  *	Init & Exit
237  */
238 
239 static int hpwdt_init_nmi_decoding(struct pci_dev *dev)
240 {
241 #ifdef CONFIG_HPWDT_NMI_DECODING
242 	int retval;
243 	/*
244 	 * Only one function can register for NMI_UNKNOWN
245 	 */
246 	retval = register_nmi_handler(NMI_UNKNOWN, hpwdt_pretimeout, 0, "hpwdt");
247 	if (retval)
248 		goto error;
249 	retval = register_nmi_handler(NMI_SERR, hpwdt_pretimeout, 0, "hpwdt");
250 	if (retval)
251 		goto error1;
252 	retval = register_nmi_handler(NMI_IO_CHECK, hpwdt_pretimeout, 0, "hpwdt");
253 	if (retval)
254 		goto error2;
255 
256 	dev_info(&dev->dev,
257 		"HPE Watchdog Timer Driver: NMI decoding initialized\n");
258 
259 	return 0;
260 
261 error2:
262 	unregister_nmi_handler(NMI_SERR, "hpwdt");
263 error1:
264 	unregister_nmi_handler(NMI_UNKNOWN, "hpwdt");
265 error:
266 	dev_warn(&dev->dev,
267 		"Unable to register a die notifier (err=%d).\n",
268 		retval);
269 	return retval;
270 #endif	/* CONFIG_HPWDT_NMI_DECODING */
271 	return 0;
272 }
273 
274 static void hpwdt_exit_nmi_decoding(void)
275 {
276 #ifdef CONFIG_HPWDT_NMI_DECODING
277 	unregister_nmi_handler(NMI_UNKNOWN, "hpwdt");
278 	unregister_nmi_handler(NMI_SERR, "hpwdt");
279 	unregister_nmi_handler(NMI_IO_CHECK, "hpwdt");
280 #endif
281 }
282 
283 static int hpwdt_init_one(struct pci_dev *dev,
284 					const struct pci_device_id *ent)
285 {
286 	int retval;
287 
288 	/*
289 	 * First let's find out if we are on an iLO2+ server. We will
290 	 * not run on a legacy ASM box.
291 	 * So we only support the G5 ProLiant servers and higher.
292 	 */
293 	if (dev->subsystem_vendor != PCI_VENDOR_ID_HP &&
294 	    dev->subsystem_vendor != PCI_VENDOR_ID_HP_3PAR) {
295 		dev_warn(&dev->dev,
296 			"This server does not have an iLO2+ ASIC.\n");
297 		return -ENODEV;
298 	}
299 
300 	if (pci_match_id(hpwdt_blacklist, dev)) {
301 		dev_dbg(&dev->dev, "Not supported on this device\n");
302 		return -ENODEV;
303 	}
304 
305 	if (pci_enable_device(dev)) {
306 		dev_warn(&dev->dev,
307 			"Not possible to enable PCI Device: 0x%x:0x%x.\n",
308 			ent->vendor, ent->device);
309 		return -ENODEV;
310 	}
311 
312 	pci_mem_addr = pci_iomap(dev, 1, 0x80);
313 	if (!pci_mem_addr) {
314 		dev_warn(&dev->dev,
315 			"Unable to detect the iLO2+ server memory.\n");
316 		retval = -ENOMEM;
317 		goto error_pci_iomap;
318 	}
319 	hpwdt_nmistat	= pci_mem_addr + 0x6e;
320 	hpwdt_timer_reg = pci_mem_addr + 0x70;
321 	hpwdt_timer_con = pci_mem_addr + 0x72;
322 
323 	/* Have the core update running timer until user space is ready */
324 	if (hpwdt_hw_is_running()) {
325 		dev_info(&dev->dev, "timer is running\n");
326 		set_bit(WDOG_HW_RUNNING, &hpwdt_dev.status);
327 	}
328 
329 	/* Initialize NMI Decoding functionality */
330 	retval = hpwdt_init_nmi_decoding(dev);
331 	if (retval != 0)
332 		goto error_init_nmi_decoding;
333 
334 	watchdog_stop_on_unregister(&hpwdt_dev);
335 	watchdog_set_nowayout(&hpwdt_dev, nowayout);
336 	watchdog_init_timeout(&hpwdt_dev, soft_margin, NULL);
337 
338 	if (is_kdump_kernel()) {
339 		pretimeout = false;
340 		kdumptimeout = 0;
341 	}
342 
343 	if (pretimeout && hpwdt_dev.timeout <= PRETIMEOUT_SEC) {
344 		dev_warn(&dev->dev, "timeout <= pretimeout. Setting pretimeout to zero\n");
345 		pretimeout = false;
346 	}
347 	hpwdt_dev.pretimeout = pretimeout ? PRETIMEOUT_SEC : 0;
348 	kdumptimeout = min(kdumptimeout, HPWDT_MAX_TIMER);
349 
350 	hpwdt_dev.parent = &dev->dev;
351 	retval = watchdog_register_device(&hpwdt_dev);
352 	if (retval < 0)
353 		goto error_wd_register;
354 
355 	dev_info(&dev->dev, "HPE Watchdog Timer Driver: Version: %s\n",
356 				HPWDT_VERSION);
357 	dev_info(&dev->dev, "timeout: %d seconds (nowayout=%d)\n",
358 				hpwdt_dev.timeout, nowayout);
359 	dev_info(&dev->dev, "pretimeout: %s.\n",
360 				pretimeout ? "on" : "off");
361 	dev_info(&dev->dev, "kdumptimeout: %d.\n", kdumptimeout);
362 
363 	if (dev->subsystem_vendor == PCI_VENDOR_ID_HP_3PAR)
364 		ilo5 = true;
365 
366 	return 0;
367 
368 error_wd_register:
369 	hpwdt_exit_nmi_decoding();
370 error_init_nmi_decoding:
371 	pci_iounmap(dev, pci_mem_addr);
372 error_pci_iomap:
373 	pci_disable_device(dev);
374 	return retval;
375 }
376 
377 static void hpwdt_exit(struct pci_dev *dev)
378 {
379 	watchdog_unregister_device(&hpwdt_dev);
380 	hpwdt_exit_nmi_decoding();
381 	pci_iounmap(dev, pci_mem_addr);
382 	pci_disable_device(dev);
383 }
384 
385 static struct pci_driver hpwdt_driver = {
386 	.name = "hpwdt",
387 	.id_table = hpwdt_devices,
388 	.probe = hpwdt_init_one,
389 	.remove = hpwdt_exit,
390 };
391 
392 MODULE_AUTHOR("Tom Mingarelli");
393 MODULE_DESCRIPTION("hpe watchdog driver");
394 MODULE_LICENSE("GPL");
395 MODULE_VERSION(HPWDT_VERSION);
396 
397 module_param(soft_margin, int, 0);
398 MODULE_PARM_DESC(soft_margin, "Watchdog timeout in seconds");
399 
400 module_param_named(timeout, soft_margin, int, 0);
401 MODULE_PARM_DESC(timeout, "Alias of soft_margin");
402 
403 module_param(nowayout, bool, 0);
404 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
405 		__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
406 
407 module_param(kdumptimeout, int, 0444);
408 MODULE_PARM_DESC(kdumptimeout, "Timeout applied for crash kernel transition in seconds");
409 
410 #ifdef CONFIG_HPWDT_NMI_DECODING
411 module_param(pretimeout, bool, 0);
412 MODULE_PARM_DESC(pretimeout, "Watchdog pretimeout enabled");
413 #endif
414 
415 module_pci_driver(hpwdt_driver);
416