xref: /openbmc/linux/drivers/watchdog/hpwdt.c (revision 95298d63)
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 
25 #define HPWDT_VERSION			"2.0.3"
26 #define SECS_TO_TICKS(secs)		((secs) * 1000 / 128)
27 #define TICKS_TO_SECS(ticks)		((ticks) * 128 / 1000)
28 #define HPWDT_MAX_TICKS			65535
29 #define HPWDT_MAX_TIMER			TICKS_TO_SECS(HPWDT_MAX_TICKS)
30 #define DEFAULT_MARGIN			30
31 #define PRETIMEOUT_SEC			9
32 
33 static bool ilo5;
34 static unsigned int soft_margin = DEFAULT_MARGIN;	/* in seconds */
35 static bool nowayout = WATCHDOG_NOWAYOUT;
36 static bool pretimeout = IS_ENABLED(CONFIG_HPWDT_NMI_DECODING);
37 static int kdumptimeout = -1;
38 
39 static void __iomem *pci_mem_addr;		/* the PCI-memory address */
40 static unsigned long __iomem *hpwdt_nmistat;
41 static unsigned long __iomem *hpwdt_timer_reg;
42 static unsigned long __iomem *hpwdt_timer_con;
43 
44 static const struct pci_device_id hpwdt_devices[] = {
45 	{ PCI_DEVICE(PCI_VENDOR_ID_COMPAQ, 0xB203) },	/* iLO2 */
46 	{ PCI_DEVICE(PCI_VENDOR_ID_HP, 0x3306) },	/* iLO3 */
47 	{0},			/* terminate list */
48 };
49 MODULE_DEVICE_TABLE(pci, hpwdt_devices);
50 
51 static const struct pci_device_id hpwdt_blacklist[] = {
52 	{ PCI_DEVICE_SUB(PCI_VENDOR_ID_HP, 0x3306, PCI_VENDOR_ID_HP, 0x1979) }, /* auxilary iLO */
53 	{ PCI_DEVICE_SUB(PCI_VENDOR_ID_HP, 0x3306, PCI_VENDOR_ID_HP_3PAR, 0x0289) },  /* CL */
54 	{0},			/* terminate list */
55 };
56 
57 static struct watchdog_device hpwdt_dev;
58 /*
59  *	Watchdog operations
60  */
61 static int hpwdt_hw_is_running(void)
62 {
63 	return ioread8(hpwdt_timer_con) & 0x01;
64 }
65 
66 static int hpwdt_start(struct watchdog_device *wdd)
67 {
68 	int control = 0x81 | (pretimeout ? 0x4 : 0);
69 	int reload = SECS_TO_TICKS(min(wdd->timeout, wdd->max_hw_heartbeat_ms/1000));
70 
71 	dev_dbg(wdd->parent, "start watchdog 0x%08x:0x%08x:0x%02x\n", wdd->timeout, reload, control);
72 	iowrite16(reload, hpwdt_timer_reg);
73 	iowrite8(control, hpwdt_timer_con);
74 
75 	return 0;
76 }
77 
78 static void hpwdt_stop(void)
79 {
80 	unsigned long data;
81 
82 	pr_debug("stop  watchdog\n");
83 
84 	data = ioread8(hpwdt_timer_con);
85 	data &= 0xFE;
86 	iowrite8(data, hpwdt_timer_con);
87 }
88 
89 static int hpwdt_stop_core(struct watchdog_device *wdd)
90 {
91 	hpwdt_stop();
92 
93 	return 0;
94 }
95 
96 static void hpwdt_ping_ticks(int val)
97 {
98 	val = min(val, HPWDT_MAX_TICKS);
99 	iowrite16(val, hpwdt_timer_reg);
100 }
101 
102 static int hpwdt_ping(struct watchdog_device *wdd)
103 {
104 	int reload = SECS_TO_TICKS(min(wdd->timeout, wdd->max_hw_heartbeat_ms/1000));
105 
106 	dev_dbg(wdd->parent, "ping  watchdog 0x%08x:0x%08x\n", wdd->timeout, reload);
107 	hpwdt_ping_ticks(reload);
108 
109 	return 0;
110 }
111 
112 static unsigned int hpwdt_gettimeleft(struct watchdog_device *wdd)
113 {
114 	return TICKS_TO_SECS(ioread16(hpwdt_timer_reg));
115 }
116 
117 static int hpwdt_settimeout(struct watchdog_device *wdd, unsigned int val)
118 {
119 	dev_dbg(wdd->parent, "set_timeout = %d\n", val);
120 
121 	wdd->timeout = val;
122 	if (val <= wdd->pretimeout) {
123 		dev_dbg(wdd->parent, "pretimeout < timeout. Setting to zero\n");
124 		wdd->pretimeout = 0;
125 		pretimeout = 0;
126 		if (watchdog_active(wdd))
127 			hpwdt_start(wdd);
128 	}
129 	hpwdt_ping(wdd);
130 
131 	return 0;
132 }
133 
134 #ifdef CONFIG_HPWDT_NMI_DECODING
135 static int hpwdt_set_pretimeout(struct watchdog_device *wdd, unsigned int req)
136 {
137 	unsigned int val = 0;
138 
139 	dev_dbg(wdd->parent, "set_pretimeout = %d\n", req);
140 	if (req) {
141 		val = PRETIMEOUT_SEC;
142 		if (val >= wdd->timeout)
143 			return -EINVAL;
144 	}
145 
146 	if (val != req)
147 		dev_dbg(wdd->parent, "Rounding pretimeout to: %d\n", val);
148 
149 	wdd->pretimeout = val;
150 	pretimeout = !!val;
151 
152 	if (watchdog_active(wdd))
153 		hpwdt_start(wdd);
154 
155 	return 0;
156 }
157 
158 static int hpwdt_my_nmi(void)
159 {
160 	return ioread8(hpwdt_nmistat) & 0x6;
161 }
162 
163 /*
164  *	NMI Handler
165  */
166 static int hpwdt_pretimeout(unsigned int ulReason, struct pt_regs *regs)
167 {
168 	unsigned int mynmi = hpwdt_my_nmi();
169 	static char panic_msg[] =
170 		"00: An NMI occurred. Depending on your system the reason "
171 		"for the NMI is logged in any one of the following resources:\n"
172 		"1. Integrated Management Log (IML)\n"
173 		"2. OA Syslog\n"
174 		"3. OA Forward Progress Log\n"
175 		"4. iLO Event Log";
176 
177 	if (ilo5 && ulReason == NMI_UNKNOWN && !mynmi)
178 		return NMI_DONE;
179 
180 	if (ilo5 && !pretimeout && !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 
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 
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 
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 (pretimeout && hpwdt_dev.timeout <= PRETIMEOUT_SEC) {
338 		dev_warn(&dev->dev, "timeout <= pretimeout. Setting pretimeout to zero\n");
339 		pretimeout = 0;
340 	}
341 	hpwdt_dev.pretimeout = pretimeout ? PRETIMEOUT_SEC : 0;
342 	kdumptimeout = min(kdumptimeout, HPWDT_MAX_TIMER);
343 
344 	hpwdt_dev.parent = &dev->dev;
345 	retval = watchdog_register_device(&hpwdt_dev);
346 	if (retval < 0)
347 		goto error_wd_register;
348 
349 	dev_info(&dev->dev, "HPE Watchdog Timer Driver: Version: %s\n",
350 				HPWDT_VERSION);
351 	dev_info(&dev->dev, "timeout: %d seconds (nowayout=%d)\n",
352 				hpwdt_dev.timeout, nowayout);
353 	dev_info(&dev->dev, "pretimeout: %s.\n",
354 				pretimeout ? "on" : "off");
355 	dev_info(&dev->dev, "kdumptimeout: %d.\n", kdumptimeout);
356 
357 	if (dev->subsystem_vendor == PCI_VENDOR_ID_HP_3PAR)
358 		ilo5 = true;
359 
360 	return 0;
361 
362 error_wd_register:
363 	hpwdt_exit_nmi_decoding();
364 error_init_nmi_decoding:
365 	pci_iounmap(dev, pci_mem_addr);
366 error_pci_iomap:
367 	pci_disable_device(dev);
368 	return retval;
369 }
370 
371 static void hpwdt_exit(struct pci_dev *dev)
372 {
373 	watchdog_unregister_device(&hpwdt_dev);
374 	hpwdt_exit_nmi_decoding();
375 	pci_iounmap(dev, pci_mem_addr);
376 	pci_disable_device(dev);
377 }
378 
379 static struct pci_driver hpwdt_driver = {
380 	.name = "hpwdt",
381 	.id_table = hpwdt_devices,
382 	.probe = hpwdt_init_one,
383 	.remove = hpwdt_exit,
384 };
385 
386 MODULE_AUTHOR("Tom Mingarelli");
387 MODULE_DESCRIPTION("hpe watchdog driver");
388 MODULE_LICENSE("GPL");
389 MODULE_VERSION(HPWDT_VERSION);
390 
391 module_param(soft_margin, int, 0);
392 MODULE_PARM_DESC(soft_margin, "Watchdog timeout in seconds");
393 
394 module_param_named(timeout, soft_margin, int, 0);
395 MODULE_PARM_DESC(timeout, "Alias of soft_margin");
396 
397 module_param(nowayout, bool, 0);
398 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
399 		__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
400 
401 module_param(kdumptimeout, int, 0444);
402 MODULE_PARM_DESC(kdumptimeout, "Timeout applied for crash kernel transition in seconds");
403 
404 #ifdef CONFIG_HPWDT_NMI_DECODING
405 module_param(pretimeout, bool, 0);
406 MODULE_PARM_DESC(pretimeout, "Watchdog pretimeout enabled");
407 #endif
408 
409 module_pci_driver(hpwdt_driver);
410