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#ifdef CONFIG_HPWDT_NMI_DECODING
24#include <asm/nmi.h>
25#endif
26#include <linux/crash_dump.h>
27
28#define HPWDT_VERSION			"2.0.4"
29#define SECS_TO_TICKS(secs)		((secs) * 1000 / 128)
30#define TICKS_TO_SECS(ticks)		((ticks) * 128 / 1000)
31#define HPWDT_MAX_TICKS			65535
32#define HPWDT_MAX_TIMER			TICKS_TO_SECS(HPWDT_MAX_TICKS)
33#define DEFAULT_MARGIN			30
34#define PRETIMEOUT_SEC			9
35
36static bool ilo5;
37static unsigned int soft_margin = DEFAULT_MARGIN;	/* in seconds */
38static bool nowayout = WATCHDOG_NOWAYOUT;
39static bool pretimeout = IS_ENABLED(CONFIG_HPWDT_NMI_DECODING);
40static int kdumptimeout = -1;
41
42static void __iomem *pci_mem_addr;		/* the PCI-memory address */
43static unsigned long __iomem *hpwdt_nmistat;
44static unsigned long __iomem *hpwdt_timer_reg;
45static unsigned long __iomem *hpwdt_timer_con;
46
47static const struct pci_device_id hpwdt_devices[] = {
48	{ PCI_DEVICE(PCI_VENDOR_ID_COMPAQ, 0xB203) },	/* iLO2 */
49	{ PCI_DEVICE(PCI_VENDOR_ID_HP, 0x3306) },	/* iLO3 */
50	{ PCI_DEVICE(PCI_VENDOR_ID_HP_3PAR, 0x0389) },	/* PCtrl */
51	{0},			/* terminate list */
52};
53MODULE_DEVICE_TABLE(pci, hpwdt_devices);
54
55static const struct pci_device_id hpwdt_blacklist[] = {
56	{ PCI_DEVICE_SUB(PCI_VENDOR_ID_HP, 0x3306, PCI_VENDOR_ID_HP, 0x1979) }, /* auxilary iLO */
57	{ PCI_DEVICE_SUB(PCI_VENDOR_ID_HP, 0x3306, PCI_VENDOR_ID_HP_3PAR, 0x0289) },  /* CL */
58	{0},			/* terminate list */
59};
60
61static struct watchdog_device hpwdt_dev;
62/*
63 *	Watchdog operations
64 */
65static int hpwdt_hw_is_running(void)
66{
67	return ioread8(hpwdt_timer_con) & 0x01;
68}
69
70static int hpwdt_start(struct watchdog_device *wdd)
71{
72	int control = 0x81 | (pretimeout ? 0x4 : 0);
73	int reload = SECS_TO_TICKS(min(wdd->timeout, wdd->max_hw_heartbeat_ms/1000));
74
75	dev_dbg(wdd->parent, "start watchdog 0x%08x:0x%08x:0x%02x\n", wdd->timeout, reload, control);
76	iowrite16(reload, hpwdt_timer_reg);
77	iowrite8(control, hpwdt_timer_con);
78
79	return 0;
80}
81
82static void hpwdt_stop(void)
83{
84	unsigned long data;
85
86	pr_debug("stop  watchdog\n");
87
88	data = ioread8(hpwdt_timer_con);
89	data &= 0xFE;
90	iowrite8(data, hpwdt_timer_con);
91}
92
93static int hpwdt_stop_core(struct watchdog_device *wdd)
94{
95	hpwdt_stop();
96
97	return 0;
98}
99
100static void hpwdt_ping_ticks(int val)
101{
102	val = min(val, HPWDT_MAX_TICKS);
103	iowrite16(val, hpwdt_timer_reg);
104}
105
106static int hpwdt_ping(struct watchdog_device *wdd)
107{
108	int reload = SECS_TO_TICKS(min(wdd->timeout, wdd->max_hw_heartbeat_ms/1000));
109
110	dev_dbg(wdd->parent, "ping  watchdog 0x%08x:0x%08x\n", wdd->timeout, reload);
111	hpwdt_ping_ticks(reload);
112
113	return 0;
114}
115
116static unsigned int hpwdt_gettimeleft(struct watchdog_device *wdd)
117{
118	return TICKS_TO_SECS(ioread16(hpwdt_timer_reg));
119}
120
121static int hpwdt_settimeout(struct watchdog_device *wdd, unsigned int val)
122{
123	dev_dbg(wdd->parent, "set_timeout = %d\n", val);
124
125	wdd->timeout = val;
126	if (val <= wdd->pretimeout) {
127		dev_dbg(wdd->parent, "pretimeout < timeout. Setting to zero\n");
128		wdd->pretimeout = 0;
129		pretimeout = false;
130		if (watchdog_active(wdd))
131			hpwdt_start(wdd);
132	}
133	hpwdt_ping(wdd);
134
135	return 0;
136}
137
138#ifdef CONFIG_HPWDT_NMI_DECODING
139static int hpwdt_set_pretimeout(struct watchdog_device *wdd, unsigned int req)
140{
141	unsigned int val = 0;
142
143	dev_dbg(wdd->parent, "set_pretimeout = %d\n", req);
144	if (req) {
145		val = PRETIMEOUT_SEC;
146		if (val >= wdd->timeout)
147			return -EINVAL;
148	}
149
150	if (val != req)
151		dev_dbg(wdd->parent, "Rounding pretimeout to: %d\n", val);
152
153	wdd->pretimeout = val;
154	pretimeout = !!val;
155
156	if (watchdog_active(wdd))
157		hpwdt_start(wdd);
158
159	return 0;
160}
161
162static int hpwdt_my_nmi(void)
163{
164	return ioread8(hpwdt_nmistat) & 0x6;
165}
166
167/*
168 *	NMI Handler
169 */
170static int hpwdt_pretimeout(unsigned int ulReason, struct pt_regs *regs)
171{
172	unsigned int mynmi = hpwdt_my_nmi();
173	static char panic_msg[] =
174		"00: An NMI occurred. Depending on your system the reason "
175		"for the NMI is logged in any one of the following resources:\n"
176		"1. Integrated Management Log (IML)\n"
177		"2. OA Syslog\n"
178		"3. OA Forward Progress Log\n"
179		"4. iLO Event Log";
180
181	if (ulReason == NMI_UNKNOWN && !mynmi)
182		return NMI_DONE;
183
184	if (ilo5 && !pretimeout && !mynmi)
185		return NMI_DONE;
186
187	if (kdumptimeout < 0)
188		hpwdt_stop();
189	else if (kdumptimeout == 0)
190		;
191	else {
192		unsigned int val = max((unsigned int)kdumptimeout, hpwdt_dev.timeout);
193		hpwdt_ping_ticks(SECS_TO_TICKS(val));
194	}
195
196	hex_byte_pack(panic_msg, mynmi);
197	nmi_panic(regs, panic_msg);
198
199	return NMI_HANDLED;
200}
201#endif /* CONFIG_HPWDT_NMI_DECODING */
202
203
204static const struct watchdog_info ident = {
205	.options = WDIOF_PRETIMEOUT    |
206		   WDIOF_SETTIMEOUT    |
207		   WDIOF_KEEPALIVEPING |
208		   WDIOF_MAGICCLOSE,
209	.identity = "HPE iLO2+ HW Watchdog Timer",
210};
211
212/*
213 *	Kernel interfaces
214 */
215
216static const struct watchdog_ops hpwdt_ops = {
217	.owner		= THIS_MODULE,
218	.start		= hpwdt_start,
219	.stop		= hpwdt_stop_core,
220	.ping		= hpwdt_ping,
221	.set_timeout	= hpwdt_settimeout,
222	.get_timeleft	= hpwdt_gettimeleft,
223#ifdef CONFIG_HPWDT_NMI_DECODING
224	.set_pretimeout	= hpwdt_set_pretimeout,
225#endif
226};
227
228static struct watchdog_device hpwdt_dev = {
229	.info		= &ident,
230	.ops		= &hpwdt_ops,
231	.min_timeout	= 1,
232	.timeout	= DEFAULT_MARGIN,
233	.pretimeout	= PRETIMEOUT_SEC,
234	.max_hw_heartbeat_ms	= HPWDT_MAX_TIMER * 1000,
235};
236
237
238/*
239 *	Init & Exit
240 */
241
242static int hpwdt_init_nmi_decoding(struct pci_dev *dev)
243{
244#ifdef CONFIG_HPWDT_NMI_DECODING
245	int retval;
246	/*
247	 * Only one function can register for NMI_UNKNOWN
248	 */
249	retval = register_nmi_handler(NMI_UNKNOWN, hpwdt_pretimeout, 0, "hpwdt");
250	if (retval)
251		goto error;
252	retval = register_nmi_handler(NMI_SERR, hpwdt_pretimeout, 0, "hpwdt");
253	if (retval)
254		goto error1;
255	retval = register_nmi_handler(NMI_IO_CHECK, hpwdt_pretimeout, 0, "hpwdt");
256	if (retval)
257		goto error2;
258
259	dev_info(&dev->dev,
260		"HPE Watchdog Timer Driver: NMI decoding initialized\n");
261
262	return 0;
263
264error2:
265	unregister_nmi_handler(NMI_SERR, "hpwdt");
266error1:
267	unregister_nmi_handler(NMI_UNKNOWN, "hpwdt");
268error:
269	dev_warn(&dev->dev,
270		"Unable to register a die notifier (err=%d).\n",
271		retval);
272	return retval;
273#endif	/* CONFIG_HPWDT_NMI_DECODING */
274	return 0;
275}
276
277static void hpwdt_exit_nmi_decoding(void)
278{
279#ifdef CONFIG_HPWDT_NMI_DECODING
280	unregister_nmi_handler(NMI_UNKNOWN, "hpwdt");
281	unregister_nmi_handler(NMI_SERR, "hpwdt");
282	unregister_nmi_handler(NMI_IO_CHECK, "hpwdt");
283#endif
284}
285
286static int hpwdt_init_one(struct pci_dev *dev,
287					const struct pci_device_id *ent)
288{
289	int retval;
290
291	/*
292	 * First let's find out if we are on an iLO2+ server. We will
293	 * not run on a legacy ASM box.
294	 * So we only support the G5 ProLiant servers and higher.
295	 */
296	if (dev->subsystem_vendor != PCI_VENDOR_ID_HP &&
297	    dev->subsystem_vendor != PCI_VENDOR_ID_HP_3PAR) {
298		dev_warn(&dev->dev,
299			"This server does not have an iLO2+ ASIC.\n");
300		return -ENODEV;
301	}
302
303	if (pci_match_id(hpwdt_blacklist, dev)) {
304		dev_dbg(&dev->dev, "Not supported on this device\n");
305		return -ENODEV;
306	}
307
308	if (pci_enable_device(dev)) {
309		dev_warn(&dev->dev,
310			"Not possible to enable PCI Device: 0x%x:0x%x.\n",
311			ent->vendor, ent->device);
312		return -ENODEV;
313	}
314
315	pci_mem_addr = pci_iomap(dev, 1, 0x80);
316	if (!pci_mem_addr) {
317		dev_warn(&dev->dev,
318			"Unable to detect the iLO2+ server memory.\n");
319		retval = -ENOMEM;
320		goto error_pci_iomap;
321	}
322	hpwdt_nmistat	= pci_mem_addr + 0x6e;
323	hpwdt_timer_reg = pci_mem_addr + 0x70;
324	hpwdt_timer_con = pci_mem_addr + 0x72;
325
326	/* Have the core update running timer until user space is ready */
327	if (hpwdt_hw_is_running()) {
328		dev_info(&dev->dev, "timer is running\n");
329		set_bit(WDOG_HW_RUNNING, &hpwdt_dev.status);
330	}
331
332	/* Initialize NMI Decoding functionality */
333	retval = hpwdt_init_nmi_decoding(dev);
334	if (retval != 0)
335		goto error_init_nmi_decoding;
336
337	watchdog_stop_on_unregister(&hpwdt_dev);
338	watchdog_set_nowayout(&hpwdt_dev, nowayout);
339	watchdog_init_timeout(&hpwdt_dev, soft_margin, NULL);
340
341	if (is_kdump_kernel()) {
342		pretimeout = false;
343		kdumptimeout = 0;
344	}
345
346	if (pretimeout && hpwdt_dev.timeout <= PRETIMEOUT_SEC) {
347		dev_warn(&dev->dev, "timeout <= pretimeout. Setting pretimeout to zero\n");
348		pretimeout = false;
349	}
350	hpwdt_dev.pretimeout = pretimeout ? PRETIMEOUT_SEC : 0;
351	kdumptimeout = min(kdumptimeout, HPWDT_MAX_TIMER);
352
353	hpwdt_dev.parent = &dev->dev;
354	retval = watchdog_register_device(&hpwdt_dev);
355	if (retval < 0)
356		goto error_wd_register;
357
358	dev_info(&dev->dev, "HPE Watchdog Timer Driver: Version: %s\n",
359				HPWDT_VERSION);
360	dev_info(&dev->dev, "timeout: %d seconds (nowayout=%d)\n",
361				hpwdt_dev.timeout, nowayout);
362	dev_info(&dev->dev, "pretimeout: %s.\n",
363				pretimeout ? "on" : "off");
364	dev_info(&dev->dev, "kdumptimeout: %d.\n", kdumptimeout);
365
366	if (dev->subsystem_vendor == PCI_VENDOR_ID_HP_3PAR)
367		ilo5 = true;
368
369	return 0;
370
371error_wd_register:
372	hpwdt_exit_nmi_decoding();
373error_init_nmi_decoding:
374	pci_iounmap(dev, pci_mem_addr);
375error_pci_iomap:
376	pci_disable_device(dev);
377	return retval;
378}
379
380static void hpwdt_exit(struct pci_dev *dev)
381{
382	watchdog_unregister_device(&hpwdt_dev);
383	hpwdt_exit_nmi_decoding();
384	pci_iounmap(dev, pci_mem_addr);
385	pci_disable_device(dev);
386}
387
388static struct pci_driver hpwdt_driver = {
389	.name = "hpwdt",
390	.id_table = hpwdt_devices,
391	.probe = hpwdt_init_one,
392	.remove = hpwdt_exit,
393};
394
395MODULE_AUTHOR("Tom Mingarelli");
396MODULE_DESCRIPTION("hpe watchdog driver");
397MODULE_LICENSE("GPL");
398MODULE_VERSION(HPWDT_VERSION);
399
400module_param(soft_margin, int, 0);
401MODULE_PARM_DESC(soft_margin, "Watchdog timeout in seconds");
402
403module_param_named(timeout, soft_margin, int, 0);
404MODULE_PARM_DESC(timeout, "Alias of soft_margin");
405
406module_param(nowayout, bool, 0);
407MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
408		__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
409
410module_param(kdumptimeout, int, 0444);
411MODULE_PARM_DESC(kdumptimeout, "Timeout applied for crash kernel transition in seconds");
412
413#ifdef CONFIG_HPWDT_NMI_DECODING
414module_param(pretimeout, bool, 0);
415MODULE_PARM_DESC(pretimeout, "Watchdog pretimeout enabled");
416#endif
417
418module_pci_driver(hpwdt_driver);
419