xref: /openbmc/linux/drivers/watchdog/hpwdt.c (revision 7f904d7e1f3ec7c2de47c024a5a5c30988b54703)
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			"2.0.2"
26 #define SECS_TO_TICKS(secs)		((secs) * 1000 / 128)
27 #define TICKS_TO_SECS(ticks)		((ticks) * 128 / 1000)
28 #define HPWDT_MAX_TIMER			TICKS_TO_SECS(65535)
29 #define DEFAULT_MARGIN			30
30 #define PRETIMEOUT_SEC			9
31 
32 static bool ilo5;
33 static unsigned int soft_margin = DEFAULT_MARGIN;	/* in seconds */
34 static bool nowayout = WATCHDOG_NOWAYOUT;
35 static bool pretimeout = IS_ENABLED(CONFIG_HPWDT_NMI_DECODING);
36 
37 static void __iomem *pci_mem_addr;		/* the PCI-memory address */
38 static unsigned long __iomem *hpwdt_nmistat;
39 static unsigned long __iomem *hpwdt_timer_reg;
40 static unsigned long __iomem *hpwdt_timer_con;
41 
42 static const struct pci_device_id hpwdt_devices[] = {
43 	{ PCI_DEVICE(PCI_VENDOR_ID_COMPAQ, 0xB203) },	/* iLO2 */
44 	{ PCI_DEVICE(PCI_VENDOR_ID_HP, 0x3306) },	/* iLO3 */
45 	{0},			/* terminate list */
46 };
47 MODULE_DEVICE_TABLE(pci, hpwdt_devices);
48 
49 static const struct pci_device_id hpwdt_blacklist[] = {
50 	{ PCI_DEVICE_SUB(PCI_VENDOR_ID_HP, 0x3306, PCI_VENDOR_ID_HP, 0x1979) }, /* auxilary iLO */
51 	{ PCI_DEVICE_SUB(PCI_VENDOR_ID_HP, 0x3306, PCI_VENDOR_ID_HP_3PAR, 0x0289) },  /* CL */
52 	{0},			/* terminate list */
53 };
54 
55 /*
56  *	Watchdog operations
57  */
58 static int hpwdt_start(struct watchdog_device *wdd)
59 {
60 	int control = 0x81 | (pretimeout ? 0x4 : 0);
61 	int reload = SECS_TO_TICKS(wdd->timeout);
62 
63 	dev_dbg(wdd->parent, "start watchdog 0x%08x:0x%02x\n", reload, control);
64 	iowrite16(reload, hpwdt_timer_reg);
65 	iowrite8(control, hpwdt_timer_con);
66 
67 	return 0;
68 }
69 
70 static void hpwdt_stop(void)
71 {
72 	unsigned long data;
73 
74 	pr_debug("stop  watchdog\n");
75 
76 	data = ioread8(hpwdt_timer_con);
77 	data &= 0xFE;
78 	iowrite8(data, hpwdt_timer_con);
79 }
80 
81 static int hpwdt_stop_core(struct watchdog_device *wdd)
82 {
83 	hpwdt_stop();
84 
85 	return 0;
86 }
87 
88 static int hpwdt_ping(struct watchdog_device *wdd)
89 {
90 	int reload = SECS_TO_TICKS(wdd->timeout);
91 
92 	dev_dbg(wdd->parent, "ping  watchdog 0x%08x\n", reload);
93 	iowrite16(reload, hpwdt_timer_reg);
94 
95 	return 0;
96 }
97 
98 static unsigned int hpwdt_gettimeleft(struct watchdog_device *wdd)
99 {
100 	return TICKS_TO_SECS(ioread16(hpwdt_timer_reg));
101 }
102 
103 static int hpwdt_settimeout(struct watchdog_device *wdd, unsigned int val)
104 {
105 	dev_dbg(wdd->parent, "set_timeout = %d\n", val);
106 
107 	wdd->timeout = val;
108 	if (val <= wdd->pretimeout) {
109 		dev_dbg(wdd->parent, "pretimeout < timeout. Setting to zero\n");
110 		wdd->pretimeout = 0;
111 		pretimeout = 0;
112 		if (watchdog_active(wdd))
113 			hpwdt_start(wdd);
114 	}
115 	hpwdt_ping(wdd);
116 
117 	return 0;
118 }
119 
120 #ifdef CONFIG_HPWDT_NMI_DECODING
121 static int hpwdt_set_pretimeout(struct watchdog_device *wdd, unsigned int req)
122 {
123 	unsigned int val = 0;
124 
125 	dev_dbg(wdd->parent, "set_pretimeout = %d\n", req);
126 	if (req) {
127 		val = PRETIMEOUT_SEC;
128 		if (val >= wdd->timeout)
129 			return -EINVAL;
130 	}
131 
132 	if (val != req)
133 		dev_dbg(wdd->parent, "Rounding pretimeout to: %d\n", val);
134 
135 	wdd->pretimeout = val;
136 	pretimeout = !!val;
137 
138 	if (watchdog_active(wdd))
139 		hpwdt_start(wdd);
140 
141 	return 0;
142 }
143 
144 static int hpwdt_my_nmi(void)
145 {
146 	return ioread8(hpwdt_nmistat) & 0x6;
147 }
148 
149 /*
150  *	NMI Handler
151  */
152 static int hpwdt_pretimeout(unsigned int ulReason, struct pt_regs *regs)
153 {
154 	unsigned int mynmi = hpwdt_my_nmi();
155 	static char panic_msg[] =
156 		"00: An NMI occurred. Depending on your system the reason "
157 		"for the NMI is logged in any one of the following resources:\n"
158 		"1. Integrated Management Log (IML)\n"
159 		"2. OA Syslog\n"
160 		"3. OA Forward Progress Log\n"
161 		"4. iLO Event Log";
162 
163 	if (ilo5 && ulReason == NMI_UNKNOWN && !mynmi)
164 		return NMI_DONE;
165 
166 	if (ilo5 && !pretimeout && !mynmi)
167 		return NMI_DONE;
168 
169 	hpwdt_stop();
170 
171 	hex_byte_pack(panic_msg, mynmi);
172 	nmi_panic(regs, panic_msg);
173 
174 	return NMI_HANDLED;
175 }
176 #endif /* CONFIG_HPWDT_NMI_DECODING */
177 
178 
179 static const struct watchdog_info ident = {
180 	.options = WDIOF_PRETIMEOUT    |
181 		   WDIOF_SETTIMEOUT    |
182 		   WDIOF_KEEPALIVEPING |
183 		   WDIOF_MAGICCLOSE,
184 	.identity = "HPE iLO2+ HW Watchdog Timer",
185 };
186 
187 /*
188  *	Kernel interfaces
189  */
190 
191 static const struct watchdog_ops hpwdt_ops = {
192 	.owner		= THIS_MODULE,
193 	.start		= hpwdt_start,
194 	.stop		= hpwdt_stop_core,
195 	.ping		= hpwdt_ping,
196 	.set_timeout	= hpwdt_settimeout,
197 	.get_timeleft	= hpwdt_gettimeleft,
198 #ifdef CONFIG_HPWDT_NMI_DECODING
199 	.set_pretimeout	= hpwdt_set_pretimeout,
200 #endif
201 };
202 
203 static struct watchdog_device hpwdt_dev = {
204 	.info		= &ident,
205 	.ops		= &hpwdt_ops,
206 	.min_timeout	= 1,
207 	.max_timeout	= HPWDT_MAX_TIMER,
208 	.timeout	= DEFAULT_MARGIN,
209 	.pretimeout	= PRETIMEOUT_SEC,
210 };
211 
212 
213 /*
214  *	Init & Exit
215  */
216 
217 static int hpwdt_init_nmi_decoding(struct pci_dev *dev)
218 {
219 #ifdef CONFIG_HPWDT_NMI_DECODING
220 	int retval;
221 	/*
222 	 * Only one function can register for NMI_UNKNOWN
223 	 */
224 	retval = register_nmi_handler(NMI_UNKNOWN, hpwdt_pretimeout, 0, "hpwdt");
225 	if (retval)
226 		goto error;
227 	retval = register_nmi_handler(NMI_SERR, hpwdt_pretimeout, 0, "hpwdt");
228 	if (retval)
229 		goto error1;
230 	retval = register_nmi_handler(NMI_IO_CHECK, hpwdt_pretimeout, 0, "hpwdt");
231 	if (retval)
232 		goto error2;
233 
234 	dev_info(&dev->dev,
235 		"HPE Watchdog Timer Driver: NMI decoding initialized\n");
236 
237 	return 0;
238 
239 error2:
240 	unregister_nmi_handler(NMI_SERR, "hpwdt");
241 error1:
242 	unregister_nmi_handler(NMI_UNKNOWN, "hpwdt");
243 error:
244 	dev_warn(&dev->dev,
245 		"Unable to register a die notifier (err=%d).\n",
246 		retval);
247 	return retval;
248 #endif	/* CONFIG_HPWDT_NMI_DECODING */
249 	return 0;
250 }
251 
252 static void hpwdt_exit_nmi_decoding(void)
253 {
254 #ifdef CONFIG_HPWDT_NMI_DECODING
255 	unregister_nmi_handler(NMI_UNKNOWN, "hpwdt");
256 	unregister_nmi_handler(NMI_SERR, "hpwdt");
257 	unregister_nmi_handler(NMI_IO_CHECK, "hpwdt");
258 #endif
259 }
260 
261 static int hpwdt_init_one(struct pci_dev *dev,
262 					const struct pci_device_id *ent)
263 {
264 	int retval;
265 
266 	/*
267 	 * First let's find out if we are on an iLO2+ server. We will
268 	 * not run on a legacy ASM box.
269 	 * So we only support the G5 ProLiant servers and higher.
270 	 */
271 	if (dev->subsystem_vendor != PCI_VENDOR_ID_HP &&
272 	    dev->subsystem_vendor != PCI_VENDOR_ID_HP_3PAR) {
273 		dev_warn(&dev->dev,
274 			"This server does not have an iLO2+ ASIC.\n");
275 		return -ENODEV;
276 	}
277 
278 	if (pci_match_id(hpwdt_blacklist, dev)) {
279 		dev_dbg(&dev->dev, "Not supported on this device\n");
280 		return -ENODEV;
281 	}
282 
283 	if (pci_enable_device(dev)) {
284 		dev_warn(&dev->dev,
285 			"Not possible to enable PCI Device: 0x%x:0x%x.\n",
286 			ent->vendor, ent->device);
287 		return -ENODEV;
288 	}
289 
290 	pci_mem_addr = pci_iomap(dev, 1, 0x80);
291 	if (!pci_mem_addr) {
292 		dev_warn(&dev->dev,
293 			"Unable to detect the iLO2+ server memory.\n");
294 		retval = -ENOMEM;
295 		goto error_pci_iomap;
296 	}
297 	hpwdt_nmistat	= pci_mem_addr + 0x6e;
298 	hpwdt_timer_reg = pci_mem_addr + 0x70;
299 	hpwdt_timer_con = pci_mem_addr + 0x72;
300 
301 	/* Make sure that timer is disabled until /dev/watchdog is opened */
302 	hpwdt_stop();
303 
304 	/* Initialize NMI Decoding functionality */
305 	retval = hpwdt_init_nmi_decoding(dev);
306 	if (retval != 0)
307 		goto error_init_nmi_decoding;
308 
309 	watchdog_set_nowayout(&hpwdt_dev, nowayout);
310 	watchdog_init_timeout(&hpwdt_dev, soft_margin, NULL);
311 
312 	if (pretimeout && hpwdt_dev.timeout <= PRETIMEOUT_SEC) {
313 		dev_warn(&dev->dev, "timeout <= pretimeout. Setting pretimeout to zero\n");
314 		pretimeout = 0;
315 	}
316 	hpwdt_dev.pretimeout = pretimeout ? PRETIMEOUT_SEC : 0;
317 
318 	hpwdt_dev.parent = &dev->dev;
319 	retval = watchdog_register_device(&hpwdt_dev);
320 	if (retval < 0) {
321 		dev_err(&dev->dev, "watchdog register failed: %d.\n", retval);
322 		goto error_wd_register;
323 	}
324 
325 	dev_info(&dev->dev, "HPE Watchdog Timer Driver: Version: %s\n",
326 				HPWDT_VERSION);
327 	dev_info(&dev->dev, "timeout: %d seconds (nowayout=%d)\n",
328 				hpwdt_dev.timeout, nowayout);
329 	dev_info(&dev->dev, "pretimeout: %s.\n",
330 				pretimeout ? "on" : "off");
331 
332 	if (dev->subsystem_vendor == PCI_VENDOR_ID_HP_3PAR)
333 		ilo5 = true;
334 
335 	return 0;
336 
337 error_wd_register:
338 	hpwdt_exit_nmi_decoding();
339 error_init_nmi_decoding:
340 	pci_iounmap(dev, pci_mem_addr);
341 error_pci_iomap:
342 	pci_disable_device(dev);
343 	return retval;
344 }
345 
346 static void hpwdt_exit(struct pci_dev *dev)
347 {
348 	if (!nowayout)
349 		hpwdt_stop();
350 
351 	watchdog_unregister_device(&hpwdt_dev);
352 	hpwdt_exit_nmi_decoding();
353 	pci_iounmap(dev, pci_mem_addr);
354 	pci_disable_device(dev);
355 }
356 
357 static struct pci_driver hpwdt_driver = {
358 	.name = "hpwdt",
359 	.id_table = hpwdt_devices,
360 	.probe = hpwdt_init_one,
361 	.remove = hpwdt_exit,
362 };
363 
364 MODULE_AUTHOR("Tom Mingarelli");
365 MODULE_DESCRIPTION("hpe watchdog driver");
366 MODULE_LICENSE("GPL");
367 MODULE_VERSION(HPWDT_VERSION);
368 
369 module_param(soft_margin, int, 0);
370 MODULE_PARM_DESC(soft_margin, "Watchdog timeout in seconds");
371 
372 module_param_named(timeout, soft_margin, int, 0);
373 MODULE_PARM_DESC(timeout, "Alias of soft_margin");
374 
375 module_param(nowayout, bool, 0);
376 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
377 		__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
378 
379 #ifdef CONFIG_HPWDT_NMI_DECODING
380 module_param(pretimeout, bool, 0);
381 MODULE_PARM_DESC(pretimeout, "Watchdog pretimeout enabled");
382 #endif
383 
384 module_pci_driver(hpwdt_driver);
385