Merge remote-tracking branch 'stable/linux-5.15.y' into rpi-5.15.y
[platform/kernel/linux-rpi.git] / drivers / watchdog / hpwdt.c
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);