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
33static bool ilo5;
34static unsigned int soft_margin = DEFAULT_MARGIN;	/* in seconds */
35static bool nowayout = WATCHDOG_NOWAYOUT;
36static bool pretimeout = IS_ENABLED(CONFIG_HPWDT_NMI_DECODING);
37static int kdumptimeout = -1;
38
39static void __iomem *pci_mem_addr;		/* the PCI-memory address */
40static unsigned long __iomem *hpwdt_nmistat;
41static unsigned long __iomem *hpwdt_timer_reg;
42static unsigned long __iomem *hpwdt_timer_con;
43
44static 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};
49MODULE_DEVICE_TABLE(pci, hpwdt_devices);
50
51static 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
57static struct watchdog_device hpwdt_dev;
58/*
59 *	Watchdog operations
60 */
61static int hpwdt_hw_is_running(void)
62{
63	return ioread8(hpwdt_timer_con) & 0x01;
64}
65
66static 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
78static 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
89static int hpwdt_stop_core(struct watchdog_device *wdd)
90{
91	hpwdt_stop();
92
93	return 0;
94}
95
96static void hpwdt_ping_ticks(int val)
97{
98	val = min(val, HPWDT_MAX_TICKS);
99	iowrite16(val, hpwdt_timer_reg);
100}
101
102static 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
112static unsigned int hpwdt_gettimeleft(struct watchdog_device *wdd)
113{
114	return TICKS_TO_SECS(ioread16(hpwdt_timer_reg));
115}
116
117static 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
135static 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
158static int hpwdt_my_nmi(void)
159{
160	return ioread8(hpwdt_nmistat) & 0x6;
161}
162
163/*
164 *	NMI Handler
165 */
166static 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 (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
200static 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
212static 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
224static 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
238static 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
260error2:
261	unregister_nmi_handler(NMI_SERR, "hpwdt");
262error1:
263	unregister_nmi_handler(NMI_UNKNOWN, "hpwdt");
264error:
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
273static 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
282static 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
362error_wd_register:
363	hpwdt_exit_nmi_decoding();
364error_init_nmi_decoding:
365	pci_iounmap(dev, pci_mem_addr);
366error_pci_iomap:
367	pci_disable_device(dev);
368	return retval;
369}
370
371static 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
379static struct pci_driver hpwdt_driver = {
380	.name = "hpwdt",
381	.id_table = hpwdt_devices,
382	.probe = hpwdt_init_one,
383	.remove = hpwdt_exit,
384};
385
386MODULE_AUTHOR("Tom Mingarelli");
387MODULE_DESCRIPTION("hpe watchdog driver");
388MODULE_LICENSE("GPL");
389MODULE_VERSION(HPWDT_VERSION);
390
391module_param(soft_margin, int, 0);
392MODULE_PARM_DESC(soft_margin, "Watchdog timeout in seconds");
393
394module_param_named(timeout, soft_margin, int, 0);
395MODULE_PARM_DESC(timeout, "Alias of soft_margin");
396
397module_param(nowayout, bool, 0);
398MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
399		__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
400
401module_param(kdumptimeout, int, 0444);
402MODULE_PARM_DESC(kdumptimeout, "Timeout applied for crash kernel transition in seconds");
403
404#ifdef CONFIG_HPWDT_NMI_DECODING
405module_param(pretimeout, bool, 0);
406MODULE_PARM_DESC(pretimeout, "Watchdog pretimeout enabled");
407#endif
408
409module_pci_driver(hpwdt_driver);
410