xref: /openbmc/linux/drivers/watchdog/hpwdt.c (revision b7019ac5)
1 /*
2  *	HPE WatchDog Driver
3  *	based on
4  *
5  *	SoftDog	0.05:	A Software Watchdog Device
6  *
7  *	(c) Copyright 2018 Hewlett Packard Enterprise Development LP
8  *	Thomas Mingarelli <thomas.mingarelli@hpe.com>
9  *
10  *	This program is free software; you can redistribute it and/or
11  *	modify it under the terms of the GNU General Public License
12  *	version 2 as published by the Free Software Foundation
13  *
14  */
15 
16 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
17 
18 #include <linux/device.h>
19 #include <linux/io.h>
20 #include <linux/kernel.h>
21 #include <linux/module.h>
22 #include <linux/moduleparam.h>
23 #include <linux/pci.h>
24 #include <linux/pci_ids.h>
25 #include <linux/types.h>
26 #include <linux/watchdog.h>
27 #include <asm/nmi.h>
28 
29 #define HPWDT_VERSION			"2.0.2"
30 #define SECS_TO_TICKS(secs)		((secs) * 1000 / 128)
31 #define TICKS_TO_SECS(ticks)		((ticks) * 128 / 1000)
32 #define HPWDT_MAX_TIMER			TICKS_TO_SECS(65535)
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 
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 	{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 /*
60  *	Watchdog operations
61  */
62 static int hpwdt_start(struct watchdog_device *wdd)
63 {
64 	int control = 0x81 | (pretimeout ? 0x4 : 0);
65 	int reload = SECS_TO_TICKS(wdd->timeout);
66 
67 	dev_dbg(wdd->parent, "start watchdog 0x%08x:0x%02x\n", reload, control);
68 	iowrite16(reload, hpwdt_timer_reg);
69 	iowrite8(control, hpwdt_timer_con);
70 
71 	return 0;
72 }
73 
74 static void hpwdt_stop(void)
75 {
76 	unsigned long data;
77 
78 	pr_debug("stop  watchdog\n");
79 
80 	data = ioread8(hpwdt_timer_con);
81 	data &= 0xFE;
82 	iowrite8(data, hpwdt_timer_con);
83 }
84 
85 static int hpwdt_stop_core(struct watchdog_device *wdd)
86 {
87 	hpwdt_stop();
88 
89 	return 0;
90 }
91 
92 static int hpwdt_ping(struct watchdog_device *wdd)
93 {
94 	int reload = SECS_TO_TICKS(wdd->timeout);
95 
96 	dev_dbg(wdd->parent, "ping  watchdog 0x%08x\n", reload);
97 	iowrite16(reload, hpwdt_timer_reg);
98 
99 	return 0;
100 }
101 
102 static unsigned int hpwdt_gettimeleft(struct watchdog_device *wdd)
103 {
104 	return TICKS_TO_SECS(ioread16(hpwdt_timer_reg));
105 }
106 
107 static int hpwdt_settimeout(struct watchdog_device *wdd, unsigned int val)
108 {
109 	dev_dbg(wdd->parent, "set_timeout = %d\n", val);
110 
111 	wdd->timeout = val;
112 	if (val <= wdd->pretimeout) {
113 		dev_dbg(wdd->parent, "pretimeout < timeout. Setting to zero\n");
114 		wdd->pretimeout = 0;
115 		pretimeout = 0;
116 		if (watchdog_active(wdd))
117 			hpwdt_start(wdd);
118 	}
119 	hpwdt_ping(wdd);
120 
121 	return 0;
122 }
123 
124 #ifdef CONFIG_HPWDT_NMI_DECODING
125 static int hpwdt_set_pretimeout(struct watchdog_device *wdd, unsigned int req)
126 {
127 	unsigned int val = 0;
128 
129 	dev_dbg(wdd->parent, "set_pretimeout = %d\n", req);
130 	if (req) {
131 		val = PRETIMEOUT_SEC;
132 		if (val >= wdd->timeout)
133 			return -EINVAL;
134 	}
135 
136 	if (val != req)
137 		dev_dbg(wdd->parent, "Rounding pretimeout to: %d\n", val);
138 
139 	wdd->pretimeout = val;
140 	pretimeout = !!val;
141 
142 	if (watchdog_active(wdd))
143 		hpwdt_start(wdd);
144 
145 	return 0;
146 }
147 
148 static int hpwdt_my_nmi(void)
149 {
150 	return ioread8(hpwdt_nmistat) & 0x6;
151 }
152 
153 /*
154  *	NMI Handler
155  */
156 static int hpwdt_pretimeout(unsigned int ulReason, struct pt_regs *regs)
157 {
158 	unsigned int mynmi = hpwdt_my_nmi();
159 	static char panic_msg[] =
160 		"00: An NMI occurred. Depending on your system the reason "
161 		"for the NMI is logged in any one of the following resources:\n"
162 		"1. Integrated Management Log (IML)\n"
163 		"2. OA Syslog\n"
164 		"3. OA Forward Progress Log\n"
165 		"4. iLO Event Log";
166 
167 	if (ilo5 && ulReason == NMI_UNKNOWN && !mynmi)
168 		return NMI_DONE;
169 
170 	if (ilo5 && !pretimeout && !mynmi)
171 		return NMI_DONE;
172 
173 	hpwdt_stop();
174 
175 	hex_byte_pack(panic_msg, mynmi);
176 	nmi_panic(regs, panic_msg);
177 
178 	return NMI_HANDLED;
179 }
180 #endif /* CONFIG_HPWDT_NMI_DECODING */
181 
182 
183 static const struct watchdog_info ident = {
184 	.options = WDIOF_PRETIMEOUT    |
185 		   WDIOF_SETTIMEOUT    |
186 		   WDIOF_KEEPALIVEPING |
187 		   WDIOF_MAGICCLOSE,
188 	.identity = "HPE iLO2+ HW Watchdog Timer",
189 };
190 
191 /*
192  *	Kernel interfaces
193  */
194 
195 static const struct watchdog_ops hpwdt_ops = {
196 	.owner		= THIS_MODULE,
197 	.start		= hpwdt_start,
198 	.stop		= hpwdt_stop_core,
199 	.ping		= hpwdt_ping,
200 	.set_timeout	= hpwdt_settimeout,
201 	.get_timeleft	= hpwdt_gettimeleft,
202 #ifdef CONFIG_HPWDT_NMI_DECODING
203 	.set_pretimeout	= hpwdt_set_pretimeout,
204 #endif
205 };
206 
207 static struct watchdog_device hpwdt_dev = {
208 	.info		= &ident,
209 	.ops		= &hpwdt_ops,
210 	.min_timeout	= 1,
211 	.max_timeout	= HPWDT_MAX_TIMER,
212 	.timeout	= DEFAULT_MARGIN,
213 	.pretimeout	= PRETIMEOUT_SEC,
214 };
215 
216 
217 /*
218  *	Init & Exit
219  */
220 
221 static int hpwdt_init_nmi_decoding(struct pci_dev *dev)
222 {
223 #ifdef CONFIG_HPWDT_NMI_DECODING
224 	int retval;
225 	/*
226 	 * Only one function can register for NMI_UNKNOWN
227 	 */
228 	retval = register_nmi_handler(NMI_UNKNOWN, hpwdt_pretimeout, 0, "hpwdt");
229 	if (retval)
230 		goto error;
231 	retval = register_nmi_handler(NMI_SERR, hpwdt_pretimeout, 0, "hpwdt");
232 	if (retval)
233 		goto error1;
234 	retval = register_nmi_handler(NMI_IO_CHECK, hpwdt_pretimeout, 0, "hpwdt");
235 	if (retval)
236 		goto error2;
237 
238 	dev_info(&dev->dev,
239 		"HPE Watchdog Timer Driver: NMI decoding initialized\n");
240 
241 	return 0;
242 
243 error2:
244 	unregister_nmi_handler(NMI_SERR, "hpwdt");
245 error1:
246 	unregister_nmi_handler(NMI_UNKNOWN, "hpwdt");
247 error:
248 	dev_warn(&dev->dev,
249 		"Unable to register a die notifier (err=%d).\n",
250 		retval);
251 	return retval;
252 #endif	/* CONFIG_HPWDT_NMI_DECODING */
253 	return 0;
254 }
255 
256 static void hpwdt_exit_nmi_decoding(void)
257 {
258 #ifdef CONFIG_HPWDT_NMI_DECODING
259 	unregister_nmi_handler(NMI_UNKNOWN, "hpwdt");
260 	unregister_nmi_handler(NMI_SERR, "hpwdt");
261 	unregister_nmi_handler(NMI_IO_CHECK, "hpwdt");
262 #endif
263 }
264 
265 static int hpwdt_init_one(struct pci_dev *dev,
266 					const struct pci_device_id *ent)
267 {
268 	int retval;
269 
270 	/*
271 	 * First let's find out if we are on an iLO2+ server. We will
272 	 * not run on a legacy ASM box.
273 	 * So we only support the G5 ProLiant servers and higher.
274 	 */
275 	if (dev->subsystem_vendor != PCI_VENDOR_ID_HP &&
276 	    dev->subsystem_vendor != PCI_VENDOR_ID_HP_3PAR) {
277 		dev_warn(&dev->dev,
278 			"This server does not have an iLO2+ ASIC.\n");
279 		return -ENODEV;
280 	}
281 
282 	if (pci_match_id(hpwdt_blacklist, dev)) {
283 		dev_dbg(&dev->dev, "Not supported on this device\n");
284 		return -ENODEV;
285 	}
286 
287 	if (pci_enable_device(dev)) {
288 		dev_warn(&dev->dev,
289 			"Not possible to enable PCI Device: 0x%x:0x%x.\n",
290 			ent->vendor, ent->device);
291 		return -ENODEV;
292 	}
293 
294 	pci_mem_addr = pci_iomap(dev, 1, 0x80);
295 	if (!pci_mem_addr) {
296 		dev_warn(&dev->dev,
297 			"Unable to detect the iLO2+ server memory.\n");
298 		retval = -ENOMEM;
299 		goto error_pci_iomap;
300 	}
301 	hpwdt_nmistat	= pci_mem_addr + 0x6e;
302 	hpwdt_timer_reg = pci_mem_addr + 0x70;
303 	hpwdt_timer_con = pci_mem_addr + 0x72;
304 
305 	/* Make sure that timer is disabled until /dev/watchdog is opened */
306 	hpwdt_stop();
307 
308 	/* Initialize NMI Decoding functionality */
309 	retval = hpwdt_init_nmi_decoding(dev);
310 	if (retval != 0)
311 		goto error_init_nmi_decoding;
312 
313 	watchdog_set_nowayout(&hpwdt_dev, nowayout);
314 	watchdog_init_timeout(&hpwdt_dev, soft_margin, NULL);
315 
316 	if (pretimeout && hpwdt_dev.timeout <= PRETIMEOUT_SEC) {
317 		dev_warn(&dev->dev, "timeout <= pretimeout. Setting pretimeout to zero\n");
318 		pretimeout = 0;
319 	}
320 	hpwdt_dev.pretimeout = pretimeout ? PRETIMEOUT_SEC : 0;
321 
322 	hpwdt_dev.parent = &dev->dev;
323 	retval = watchdog_register_device(&hpwdt_dev);
324 	if (retval < 0) {
325 		dev_err(&dev->dev, "watchdog register failed: %d.\n", retval);
326 		goto error_wd_register;
327 	}
328 
329 	dev_info(&dev->dev, "HPE Watchdog Timer Driver: Version: %s\n",
330 				HPWDT_VERSION);
331 	dev_info(&dev->dev, "timeout: %d seconds (nowayout=%d)\n",
332 				hpwdt_dev.timeout, nowayout);
333 	dev_info(&dev->dev, "pretimeout: %s.\n",
334 				pretimeout ? "on" : "off");
335 
336 	if (dev->subsystem_vendor == PCI_VENDOR_ID_HP_3PAR)
337 		ilo5 = true;
338 
339 	return 0;
340 
341 error_wd_register:
342 	hpwdt_exit_nmi_decoding();
343 error_init_nmi_decoding:
344 	pci_iounmap(dev, pci_mem_addr);
345 error_pci_iomap:
346 	pci_disable_device(dev);
347 	return retval;
348 }
349 
350 static void hpwdt_exit(struct pci_dev *dev)
351 {
352 	if (!nowayout)
353 		hpwdt_stop();
354 
355 	watchdog_unregister_device(&hpwdt_dev);
356 	hpwdt_exit_nmi_decoding();
357 	pci_iounmap(dev, pci_mem_addr);
358 	pci_disable_device(dev);
359 }
360 
361 static struct pci_driver hpwdt_driver = {
362 	.name = "hpwdt",
363 	.id_table = hpwdt_devices,
364 	.probe = hpwdt_init_one,
365 	.remove = hpwdt_exit,
366 };
367 
368 MODULE_AUTHOR("Tom Mingarelli");
369 MODULE_DESCRIPTION("hpe watchdog driver");
370 MODULE_LICENSE("GPL");
371 MODULE_VERSION(HPWDT_VERSION);
372 
373 module_param(soft_margin, int, 0);
374 MODULE_PARM_DESC(soft_margin, "Watchdog timeout in seconds");
375 
376 module_param_named(timeout, soft_margin, int, 0);
377 MODULE_PARM_DESC(timeout, "Alias of soft_margin");
378 
379 module_param(nowayout, bool, 0);
380 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
381 		__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
382 
383 #ifdef CONFIG_HPWDT_NMI_DECODING
384 module_param(pretimeout, bool, 0);
385 MODULE_PARM_DESC(pretimeout, "Watchdog pretimeout enabled");
386 #endif
387 
388 module_pci_driver(hpwdt_driver);
389