xref: /openbmc/linux/drivers/watchdog/hpwdt.c (revision 25b892b5)
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 	{ PCI_DEVICE(PCI_VENDOR_ID_HP_3PAR, 0x0389) },	/* PCtrl */
49 	{0},			/* terminate list */
50 };
51 MODULE_DEVICE_TABLE(pci, hpwdt_devices);
52 
53 static const struct pci_device_id hpwdt_blacklist[] = {
54 	{ PCI_DEVICE_SUB(PCI_VENDOR_ID_HP, 0x3306, PCI_VENDOR_ID_HP, 0x1979) }, /* auxilary iLO */
55 	{ PCI_DEVICE_SUB(PCI_VENDOR_ID_HP, 0x3306, PCI_VENDOR_ID_HP_3PAR, 0x0289) },  /* CL */
56 	{0},			/* terminate list */
57 };
58 
59 static struct watchdog_device hpwdt_dev;
60 /*
61  *	Watchdog operations
62  */
63 static int hpwdt_hw_is_running(void)
64 {
65 	return ioread8(hpwdt_timer_con) & 0x01;
66 }
67 
68 static int hpwdt_start(struct watchdog_device *wdd)
69 {
70 	int control = 0x81 | (pretimeout ? 0x4 : 0);
71 	int reload = SECS_TO_TICKS(min(wdd->timeout, wdd->max_hw_heartbeat_ms/1000));
72 
73 	dev_dbg(wdd->parent, "start watchdog 0x%08x:0x%08x:0x%02x\n", wdd->timeout, reload, control);
74 	iowrite16(reload, hpwdt_timer_reg);
75 	iowrite8(control, hpwdt_timer_con);
76 
77 	return 0;
78 }
79 
80 static void hpwdt_stop(void)
81 {
82 	unsigned long data;
83 
84 	pr_debug("stop  watchdog\n");
85 
86 	data = ioread8(hpwdt_timer_con);
87 	data &= 0xFE;
88 	iowrite8(data, hpwdt_timer_con);
89 }
90 
91 static int hpwdt_stop_core(struct watchdog_device *wdd)
92 {
93 	hpwdt_stop();
94 
95 	return 0;
96 }
97 
98 static void hpwdt_ping_ticks(int val)
99 {
100 	val = min(val, HPWDT_MAX_TICKS);
101 	iowrite16(val, hpwdt_timer_reg);
102 }
103 
104 static int hpwdt_ping(struct watchdog_device *wdd)
105 {
106 	int reload = SECS_TO_TICKS(min(wdd->timeout, wdd->max_hw_heartbeat_ms/1000));
107 
108 	dev_dbg(wdd->parent, "ping  watchdog 0x%08x:0x%08x\n", wdd->timeout, reload);
109 	hpwdt_ping_ticks(reload);
110 
111 	return 0;
112 }
113 
114 static unsigned int hpwdt_gettimeleft(struct watchdog_device *wdd)
115 {
116 	return TICKS_TO_SECS(ioread16(hpwdt_timer_reg));
117 }
118 
119 static int hpwdt_settimeout(struct watchdog_device *wdd, unsigned int val)
120 {
121 	dev_dbg(wdd->parent, "set_timeout = %d\n", val);
122 
123 	wdd->timeout = val;
124 	if (val <= wdd->pretimeout) {
125 		dev_dbg(wdd->parent, "pretimeout < timeout. Setting to zero\n");
126 		wdd->pretimeout = 0;
127 		pretimeout = false;
128 		if (watchdog_active(wdd))
129 			hpwdt_start(wdd);
130 	}
131 	hpwdt_ping(wdd);
132 
133 	return 0;
134 }
135 
136 #ifdef CONFIG_HPWDT_NMI_DECODING
137 static int hpwdt_set_pretimeout(struct watchdog_device *wdd, unsigned int req)
138 {
139 	unsigned int val = 0;
140 
141 	dev_dbg(wdd->parent, "set_pretimeout = %d\n", req);
142 	if (req) {
143 		val = PRETIMEOUT_SEC;
144 		if (val >= wdd->timeout)
145 			return -EINVAL;
146 	}
147 
148 	if (val != req)
149 		dev_dbg(wdd->parent, "Rounding pretimeout to: %d\n", val);
150 
151 	wdd->pretimeout = val;
152 	pretimeout = !!val;
153 
154 	if (watchdog_active(wdd))
155 		hpwdt_start(wdd);
156 
157 	return 0;
158 }
159 
160 static int hpwdt_my_nmi(void)
161 {
162 	return ioread8(hpwdt_nmistat) & 0x6;
163 }
164 
165 /*
166  *	NMI Handler
167  */
168 static int hpwdt_pretimeout(unsigned int ulReason, struct pt_regs *regs)
169 {
170 	unsigned int mynmi = hpwdt_my_nmi();
171 	static char panic_msg[] =
172 		"00: An NMI occurred. Depending on your system the reason "
173 		"for the NMI is logged in any one of the following resources:\n"
174 		"1. Integrated Management Log (IML)\n"
175 		"2. OA Syslog\n"
176 		"3. OA Forward Progress Log\n"
177 		"4. iLO Event Log";
178 
179 	if (ilo5 && ulReason == NMI_UNKNOWN && !mynmi)
180 		return NMI_DONE;
181 
182 	if (ilo5 && !pretimeout && !mynmi)
183 		return NMI_DONE;
184 
185 	if (kdumptimeout < 0)
186 		hpwdt_stop();
187 	else if (kdumptimeout == 0)
188 		;
189 	else {
190 		unsigned int val = max((unsigned int)kdumptimeout, hpwdt_dev.timeout);
191 		hpwdt_ping_ticks(SECS_TO_TICKS(val));
192 	}
193 
194 	hex_byte_pack(panic_msg, mynmi);
195 	nmi_panic(regs, panic_msg);
196 
197 	return NMI_HANDLED;
198 }
199 #endif /* CONFIG_HPWDT_NMI_DECODING */
200 
201 
202 static const struct watchdog_info ident = {
203 	.options = WDIOF_PRETIMEOUT    |
204 		   WDIOF_SETTIMEOUT    |
205 		   WDIOF_KEEPALIVEPING |
206 		   WDIOF_MAGICCLOSE,
207 	.identity = "HPE iLO2+ HW Watchdog Timer",
208 };
209 
210 /*
211  *	Kernel interfaces
212  */
213 
214 static const struct watchdog_ops hpwdt_ops = {
215 	.owner		= THIS_MODULE,
216 	.start		= hpwdt_start,
217 	.stop		= hpwdt_stop_core,
218 	.ping		= hpwdt_ping,
219 	.set_timeout	= hpwdt_settimeout,
220 	.get_timeleft	= hpwdt_gettimeleft,
221 #ifdef CONFIG_HPWDT_NMI_DECODING
222 	.set_pretimeout	= hpwdt_set_pretimeout,
223 #endif
224 };
225 
226 static struct watchdog_device hpwdt_dev = {
227 	.info		= &ident,
228 	.ops		= &hpwdt_ops,
229 	.min_timeout	= 1,
230 	.timeout	= DEFAULT_MARGIN,
231 	.pretimeout	= PRETIMEOUT_SEC,
232 	.max_hw_heartbeat_ms	= HPWDT_MAX_TIMER * 1000,
233 };
234 
235 
236 /*
237  *	Init & Exit
238  */
239 
240 static int hpwdt_init_nmi_decoding(struct pci_dev *dev)
241 {
242 #ifdef CONFIG_HPWDT_NMI_DECODING
243 	int retval;
244 	/*
245 	 * Only one function can register for NMI_UNKNOWN
246 	 */
247 	retval = register_nmi_handler(NMI_UNKNOWN, hpwdt_pretimeout, 0, "hpwdt");
248 	if (retval)
249 		goto error;
250 	retval = register_nmi_handler(NMI_SERR, hpwdt_pretimeout, 0, "hpwdt");
251 	if (retval)
252 		goto error1;
253 	retval = register_nmi_handler(NMI_IO_CHECK, hpwdt_pretimeout, 0, "hpwdt");
254 	if (retval)
255 		goto error2;
256 
257 	dev_info(&dev->dev,
258 		"HPE Watchdog Timer Driver: NMI decoding initialized\n");
259 
260 	return 0;
261 
262 error2:
263 	unregister_nmi_handler(NMI_SERR, "hpwdt");
264 error1:
265 	unregister_nmi_handler(NMI_UNKNOWN, "hpwdt");
266 error:
267 	dev_warn(&dev->dev,
268 		"Unable to register a die notifier (err=%d).\n",
269 		retval);
270 	return retval;
271 #endif	/* CONFIG_HPWDT_NMI_DECODING */
272 	return 0;
273 }
274 
275 static void hpwdt_exit_nmi_decoding(void)
276 {
277 #ifdef CONFIG_HPWDT_NMI_DECODING
278 	unregister_nmi_handler(NMI_UNKNOWN, "hpwdt");
279 	unregister_nmi_handler(NMI_SERR, "hpwdt");
280 	unregister_nmi_handler(NMI_IO_CHECK, "hpwdt");
281 #endif
282 }
283 
284 static int hpwdt_init_one(struct pci_dev *dev,
285 					const struct pci_device_id *ent)
286 {
287 	int retval;
288 
289 	/*
290 	 * First let's find out if we are on an iLO2+ server. We will
291 	 * not run on a legacy ASM box.
292 	 * So we only support the G5 ProLiant servers and higher.
293 	 */
294 	if (dev->subsystem_vendor != PCI_VENDOR_ID_HP &&
295 	    dev->subsystem_vendor != PCI_VENDOR_ID_HP_3PAR) {
296 		dev_warn(&dev->dev,
297 			"This server does not have an iLO2+ ASIC.\n");
298 		return -ENODEV;
299 	}
300 
301 	if (pci_match_id(hpwdt_blacklist, dev)) {
302 		dev_dbg(&dev->dev, "Not supported on this device\n");
303 		return -ENODEV;
304 	}
305 
306 	if (pci_enable_device(dev)) {
307 		dev_warn(&dev->dev,
308 			"Not possible to enable PCI Device: 0x%x:0x%x.\n",
309 			ent->vendor, ent->device);
310 		return -ENODEV;
311 	}
312 
313 	pci_mem_addr = pci_iomap(dev, 1, 0x80);
314 	if (!pci_mem_addr) {
315 		dev_warn(&dev->dev,
316 			"Unable to detect the iLO2+ server memory.\n");
317 		retval = -ENOMEM;
318 		goto error_pci_iomap;
319 	}
320 	hpwdt_nmistat	= pci_mem_addr + 0x6e;
321 	hpwdt_timer_reg = pci_mem_addr + 0x70;
322 	hpwdt_timer_con = pci_mem_addr + 0x72;
323 
324 	/* Have the core update running timer until user space is ready */
325 	if (hpwdt_hw_is_running()) {
326 		dev_info(&dev->dev, "timer is running\n");
327 		set_bit(WDOG_HW_RUNNING, &hpwdt_dev.status);
328 	}
329 
330 	/* Initialize NMI Decoding functionality */
331 	retval = hpwdt_init_nmi_decoding(dev);
332 	if (retval != 0)
333 		goto error_init_nmi_decoding;
334 
335 	watchdog_stop_on_unregister(&hpwdt_dev);
336 	watchdog_set_nowayout(&hpwdt_dev, nowayout);
337 	watchdog_init_timeout(&hpwdt_dev, soft_margin, NULL);
338 
339 	if (is_kdump_kernel()) {
340 		pretimeout = false;
341 		kdumptimeout = 0;
342 	}
343 
344 	if (pretimeout && hpwdt_dev.timeout <= PRETIMEOUT_SEC) {
345 		dev_warn(&dev->dev, "timeout <= pretimeout. Setting pretimeout to zero\n");
346 		pretimeout = false;
347 	}
348 	hpwdt_dev.pretimeout = pretimeout ? PRETIMEOUT_SEC : 0;
349 	kdumptimeout = min(kdumptimeout, HPWDT_MAX_TIMER);
350 
351 	hpwdt_dev.parent = &dev->dev;
352 	retval = watchdog_register_device(&hpwdt_dev);
353 	if (retval < 0)
354 		goto error_wd_register;
355 
356 	dev_info(&dev->dev, "HPE Watchdog Timer Driver: Version: %s\n",
357 				HPWDT_VERSION);
358 	dev_info(&dev->dev, "timeout: %d seconds (nowayout=%d)\n",
359 				hpwdt_dev.timeout, nowayout);
360 	dev_info(&dev->dev, "pretimeout: %s.\n",
361 				pretimeout ? "on" : "off");
362 	dev_info(&dev->dev, "kdumptimeout: %d.\n", kdumptimeout);
363 
364 	if (dev->subsystem_vendor == PCI_VENDOR_ID_HP_3PAR)
365 		ilo5 = true;
366 
367 	return 0;
368 
369 error_wd_register:
370 	hpwdt_exit_nmi_decoding();
371 error_init_nmi_decoding:
372 	pci_iounmap(dev, pci_mem_addr);
373 error_pci_iomap:
374 	pci_disable_device(dev);
375 	return retval;
376 }
377 
378 static void hpwdt_exit(struct pci_dev *dev)
379 {
380 	watchdog_unregister_device(&hpwdt_dev);
381 	hpwdt_exit_nmi_decoding();
382 	pci_iounmap(dev, pci_mem_addr);
383 	pci_disable_device(dev);
384 }
385 
386 static struct pci_driver hpwdt_driver = {
387 	.name = "hpwdt",
388 	.id_table = hpwdt_devices,
389 	.probe = hpwdt_init_one,
390 	.remove = hpwdt_exit,
391 };
392 
393 MODULE_AUTHOR("Tom Mingarelli");
394 MODULE_DESCRIPTION("hpe watchdog driver");
395 MODULE_LICENSE("GPL");
396 MODULE_VERSION(HPWDT_VERSION);
397 
398 module_param(soft_margin, int, 0);
399 MODULE_PARM_DESC(soft_margin, "Watchdog timeout in seconds");
400 
401 module_param_named(timeout, soft_margin, int, 0);
402 MODULE_PARM_DESC(timeout, "Alias of soft_margin");
403 
404 module_param(nowayout, bool, 0);
405 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
406 		__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
407 
408 module_param(kdumptimeout, int, 0444);
409 MODULE_PARM_DESC(kdumptimeout, "Timeout applied for crash kernel transition in seconds");
410 
411 #ifdef CONFIG_HPWDT_NMI_DECODING
412 module_param(pretimeout, bool, 0);
413 MODULE_PARM_DESC(pretimeout, "Watchdog pretimeout enabled");
414 #endif
415 
416 module_pci_driver(hpwdt_driver);
417