~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/arch/mn10300/kernel/mn10300-watchdog.c

Version: ~ [ linux-5.2-rc1 ] ~ [ linux-5.1.2 ] ~ [ linux-5.0.16 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.43 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.119 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.176 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.179 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.139 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.67 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.39.4 ] ~ [ linux-2.6.38.8 ] ~ [ linux-2.6.37.6 ] ~ [ linux-2.6.36.4 ] ~ [ linux-2.6.35.14 ] ~ [ linux-2.6.34.15 ] ~ [ linux-2.6.33.20 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 /* MN10300 Watchdog timer
  2  *
  3  * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
  4  * Written by David Howells (dhowells@redhat.com)
  5  * - Derived from arch/i386/kernel/nmi.c
  6  *
  7  * This program is free software; you can redistribute it and/or
  8  * modify it under the terms of the GNU General Public Licence
  9  * as published by the Free Software Foundation; either version
 10  * 2 of the Licence, or (at your option) any later version.
 11  */
 12 #include <linux/module.h>
 13 #include <linux/sched.h>
 14 #include <linux/kernel.h>
 15 #include <linux/init.h>
 16 #include <linux/delay.h>
 17 #include <linux/interrupt.h>
 18 #include <linux/kernel_stat.h>
 19 #include <linux/nmi.h>
 20 #include <asm/processor.h>
 21 #include <asm/system.h>
 22 #include <asm/atomic.h>
 23 #include <asm/intctl-regs.h>
 24 #include <asm/rtc-regs.h>
 25 #include <asm/div64.h>
 26 #include <asm/smp.h>
 27 #include <asm/gdb-stub.h>
 28 #include <proc/clock.h>
 29 
 30 static DEFINE_SPINLOCK(watchdog_print_lock);
 31 static unsigned int watchdog;
 32 static unsigned int watchdog_hz = 1;
 33 unsigned int watchdog_alert_counter[NR_CPUS];
 34 
 35 EXPORT_SYMBOL(touch_nmi_watchdog);
 36 
 37 /*
 38  * the best way to detect whether a CPU has a 'hard lockup' problem
 39  * is to check its timer makes IRQ counts. If they are not
 40  * changing then that CPU has some problem.
 41  *
 42  * since NMIs dont listen to _any_ locks, we have to be extremely
 43  * careful not to rely on unsafe variables. The printk might lock
 44  * up though, so we have to break up any console locks first ...
 45  * [when there will be more tty-related locks, break them up
 46  *  here too!]
 47  */
 48 static unsigned int last_irq_sums[NR_CPUS];
 49 
 50 int __init check_watchdog(void)
 51 {
 52         irq_cpustat_t tmp[1];
 53 
 54         printk(KERN_INFO "Testing Watchdog... ");
 55 
 56         memcpy(tmp, irq_stat, sizeof(tmp));
 57         local_irq_enable();
 58         mdelay((10 * 1000) / watchdog_hz); /* wait 10 ticks */
 59         local_irq_disable();
 60 
 61         if (nmi_count(0) - tmp[0].__nmi_count <= 5) {
 62                 printk(KERN_WARNING "CPU#%d: Watchdog appears to be stuck!\n",
 63                        0);
 64                 return -1;
 65         }
 66 
 67         printk(KERN_INFO "OK.\n");
 68 
 69         /* now that we know it works we can reduce NMI frequency to something
 70          * more reasonable; makes a difference in some configs
 71          */
 72         watchdog_hz = 1;
 73 
 74         return 0;
 75 }
 76 
 77 static int __init setup_watchdog(char *str)
 78 {
 79         unsigned tmp;
 80         int opt;
 81         u8 ctr;
 82 
 83         get_option(&str, &opt);
 84         if (opt != 1)
 85                 return 0;
 86 
 87         watchdog = opt;
 88         if (watchdog) {
 89                 set_intr_stub(EXCEP_WDT, watchdog_handler);
 90                 ctr = WDCTR_WDCK_65536th;
 91                 WDCTR = WDCTR_WDRST | ctr;
 92                 WDCTR = ctr;
 93                 tmp = WDCTR;
 94 
 95                 tmp = __muldiv64u(1 << (16 + ctr * 2), 1000000, MN10300_WDCLK);
 96                 tmp = 1000000000 / tmp;
 97                 watchdog_hz = (tmp + 500) / 1000;
 98         }
 99 
100         return 1;
101 }
102 
103 __setup("watchdog=", setup_watchdog);
104 
105 void __init watchdog_go(void)
106 {
107         u8 wdt;
108 
109         if (watchdog) {
110                 printk(KERN_INFO "Watchdog: running at %uHz\n", watchdog_hz);
111                 wdt = WDCTR & ~WDCTR_WDCNE;
112                 WDCTR = wdt | WDCTR_WDRST;
113                 wdt = WDCTR;
114                 WDCTR = wdt | WDCTR_WDCNE;
115                 wdt = WDCTR;
116 
117                 check_watchdog();
118         }
119 }
120 
121 #ifdef CONFIG_SMP
122 static void watchdog_dump_register(void *dummy)
123 {
124         printk(KERN_ERR "--- Register Dump (CPU%d) ---\n", CPUID);
125         show_registers(current_frame());
126 }
127 #endif
128 
129 asmlinkage
130 void watchdog_interrupt(struct pt_regs *regs, enum exception_code excep)
131 {
132         /*
133          * Since current-> is always on the stack, and we always switch
134          * the stack NMI-atomically, it's safe to use smp_processor_id().
135          */
136         int sum, cpu;
137         int irq = NMIIRQ;
138         u8 wdt, tmp;
139 
140         wdt = WDCTR & ~WDCTR_WDCNE;
141         WDCTR = wdt;
142         tmp = WDCTR;
143         NMICR = NMICR_WDIF;
144 
145         nmi_count(smp_processor_id())++;
146         kstat_incr_irqs_this_cpu(irq, irq_to_desc(irq));
147 
148         for_each_online_cpu(cpu) {
149 
150                 sum = irq_stat[cpu].__irq_count;
151 
152                 if ((last_irq_sums[cpu] == sum)
153 #if defined(CONFIG_GDBSTUB) && defined(CONFIG_SMP)
154                         && !(CHK_GDBSTUB_BUSY()
155                              || atomic_read(&cpu_doing_single_step))
156 #endif
157                         ) {
158                         /*
159                          * Ayiee, looks like this CPU is stuck ...
160                          * wait a few IRQs (5 seconds) before doing the oops ...
161                          */
162                         watchdog_alert_counter[cpu]++;
163                         if (watchdog_alert_counter[cpu] == 5 * watchdog_hz) {
164                                 spin_lock(&watchdog_print_lock);
165                                 /*
166                                  * We are in trouble anyway, lets at least try
167                                  * to get a message out.
168                                  */
169                                 bust_spinlocks(1);
170                                 printk(KERN_ERR
171                                        "NMI Watchdog detected LOCKUP on CPU%d,"
172                                        " pc %08lx, registers:\n",
173                                        cpu, regs->pc);
174 #ifdef CONFIG_SMP
175                                 printk(KERN_ERR
176                                        "--- Register Dump (CPU%d) ---\n",
177                                        CPUID);
178 #endif
179                                 show_registers(regs);
180 #ifdef CONFIG_SMP
181                                 smp_nmi_call_function(watchdog_dump_register,
182                                         NULL, 1);
183 #endif
184                                 printk(KERN_NOTICE "console shuts up ...\n");
185                                 console_silent();
186                                 spin_unlock(&watchdog_print_lock);
187                                 bust_spinlocks(0);
188 #ifdef CONFIG_GDBSTUB
189                                 if (CHK_GDBSTUB_BUSY_AND_ACTIVE())
190                                         gdbstub_exception(regs, excep);
191                                 else
192                                         gdbstub_intercept(regs, excep);
193 #endif
194                                 do_exit(SIGSEGV);
195                         }
196                 } else {
197                         last_irq_sums[cpu] = sum;
198                         watchdog_alert_counter[cpu] = 0;
199                 }
200         }
201 
202         WDCTR = wdt | WDCTR_WDRST;
203         tmp = WDCTR;
204         WDCTR = wdt | WDCTR_WDCNE;
205         tmp = WDCTR;
206 }
207 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp