Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/arch/parisc/kernel/time.c |
| 3 | * |
| 4 | * Copyright (C) 1991, 1992, 1995 Linus Torvalds |
| 5 | * Modifications for ARM (C) 1994, 1995, 1996,1997 Russell King |
| 6 | * Copyright (C) 1999 SuSE GmbH, (Philipp Rumpf, prumpf@tux.org) |
| 7 | * |
| 8 | * 1994-07-02 Alan Modra |
| 9 | * fixed set_rtc_mmss, fixed time.year for >= 2000, new mktime |
| 10 | * 1998-12-20 Updated NTP code according to technical memorandum Jan '96 |
| 11 | * "A Kernel Model for Precision Timekeeping" by Dave Mills |
| 12 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 13 | #include <linux/errno.h> |
| 14 | #include <linux/module.h> |
Arnd Bergmann | ca6da80 | 2016-05-30 20:57:55 +0200 | [diff] [blame] | 15 | #include <linux/rtc.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 16 | #include <linux/sched.h> |
| 17 | #include <linux/kernel.h> |
| 18 | #include <linux/param.h> |
| 19 | #include <linux/string.h> |
| 20 | #include <linux/mm.h> |
| 21 | #include <linux/interrupt.h> |
| 22 | #include <linux/time.h> |
| 23 | #include <linux/init.h> |
| 24 | #include <linux/smp.h> |
| 25 | #include <linux/profile.h> |
Helge Deller | 12df29b | 2007-01-02 23:54:16 +0100 | [diff] [blame] | 26 | #include <linux/clocksource.h> |
Kyle McMartin | 9eb1686 | 2008-09-10 14:24:07 +0000 | [diff] [blame] | 27 | #include <linux/platform_device.h> |
Helge Deller | d75f054 | 2009-02-09 00:43:36 +0100 | [diff] [blame] | 28 | #include <linux/ftrace.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 29 | |
| 30 | #include <asm/uaccess.h> |
| 31 | #include <asm/io.h> |
| 32 | #include <asm/irq.h> |
Rolf Eike Beer | 4a8a078 | 2012-05-10 23:08:17 +0200 | [diff] [blame] | 33 | #include <asm/page.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 34 | #include <asm/param.h> |
| 35 | #include <asm/pdc.h> |
| 36 | #include <asm/led.h> |
| 37 | |
| 38 | #include <linux/timex.h> |
| 39 | |
Grant Grundler | bed583f | 2006-09-08 23:29:22 -0700 | [diff] [blame] | 40 | static unsigned long clocktick __read_mostly; /* timer cycles per tick */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 41 | |
Helge Deller | 54b66800 | 2016-04-20 21:34:15 +0200 | [diff] [blame] | 42 | #ifndef CONFIG_64BIT |
| 43 | /* |
| 44 | * The processor-internal cycle counter (Control Register 16) is used as time |
| 45 | * source for the sched_clock() function. This register is 64bit wide on a |
| 46 | * 64-bit kernel and 32bit on a 32-bit kernel. Since sched_clock() always |
| 47 | * requires a 64bit counter we emulate on the 32-bit kernel the higher 32bits |
| 48 | * with a per-cpu variable which we increase every time the counter |
| 49 | * wraps-around (which happens every ~4 secounds). |
| 50 | */ |
| 51 | static DEFINE_PER_CPU(unsigned long, cr16_high_32_bits); |
| 52 | #endif |
| 53 | |
Matthew Wilcox | 1604f31 | 2006-10-04 15:12:52 -0600 | [diff] [blame] | 54 | /* |
| 55 | * We keep time on PA-RISC Linux by using the Interval Timer which is |
| 56 | * a pair of registers; one is read-only and one is write-only; both |
| 57 | * accessed through CR16. The read-only register is 32 or 64 bits wide, |
| 58 | * and increments by 1 every CPU clock tick. The architecture only |
| 59 | * guarantees us a rate between 0.5 and 2, but all implementations use a |
| 60 | * rate of 1. The write-only register is 32-bits wide. When the lowest |
| 61 | * 32 bits of the read-only register compare equal to the write-only |
| 62 | * register, it raises a maskable external interrupt. Each processor has |
| 63 | * an Interval Timer of its own and they are not synchronised. |
| 64 | * |
| 65 | * We want to generate an interrupt every 1/HZ seconds. So we program |
| 66 | * CR16 to interrupt every @clocktick cycles. The it_value in cpu_data |
| 67 | * is programmed with the intended time of the next tick. We can be |
| 68 | * held off for an arbitrarily long period of time by interrupts being |
| 69 | * disabled, so we may miss one or more ticks. |
| 70 | */ |
Helge Deller | d75f054 | 2009-02-09 00:43:36 +0100 | [diff] [blame] | 71 | irqreturn_t __irq_entry timer_interrupt(int irq, void *dev_id) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 72 | { |
Grant Grundler | 84be31b | 2009-06-01 00:20:23 +0000 | [diff] [blame] | 73 | unsigned long now, now2; |
Grant Grundler | bed583f | 2006-09-08 23:29:22 -0700 | [diff] [blame] | 74 | unsigned long next_tick; |
Grant Grundler | 84be31b | 2009-06-01 00:20:23 +0000 | [diff] [blame] | 75 | unsigned long cycles_elapsed, ticks_elapsed = 1; |
Grant Grundler | 6e5dc42 | 2006-09-10 12:57:55 -0700 | [diff] [blame] | 76 | unsigned long cycles_remainder; |
| 77 | unsigned int cpu = smp_processor_id(); |
Helge Deller | ef017be | 2008-12-31 03:12:10 +0000 | [diff] [blame] | 78 | struct cpuinfo_parisc *cpuinfo = &per_cpu(cpu_data, cpu); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 79 | |
Grant Grundler | 6b799d9 | 2006-09-04 13:56:11 -0700 | [diff] [blame] | 80 | /* gcc can optimize for "read-only" case with a local clocktick */ |
Grant Grundler | 6e5dc42 | 2006-09-10 12:57:55 -0700 | [diff] [blame] | 81 | unsigned long cpt = clocktick; |
Grant Grundler | 6b799d9 | 2006-09-04 13:56:11 -0700 | [diff] [blame] | 82 | |
Matthew Wilcox | be577a5 | 2006-10-06 20:47:23 -0600 | [diff] [blame] | 83 | profile_tick(CPU_PROFILING); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 84 | |
Grant Grundler | bed583f | 2006-09-08 23:29:22 -0700 | [diff] [blame] | 85 | /* Initialize next_tick to the expected tick time. */ |
Matthew Wilcox | c7753f1 | 2006-10-07 06:01:11 -0600 | [diff] [blame] | 86 | next_tick = cpuinfo->it_value; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 87 | |
Grant Grundler | 84be31b | 2009-06-01 00:20:23 +0000 | [diff] [blame] | 88 | /* Get current cycle counter (Control Register 16). */ |
Grant Grundler | bed583f | 2006-09-08 23:29:22 -0700 | [diff] [blame] | 89 | now = mfctl(16); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 90 | |
Grant Grundler | bed583f | 2006-09-08 23:29:22 -0700 | [diff] [blame] | 91 | cycles_elapsed = now - next_tick; |
| 92 | |
Grant Grundler | 84be31b | 2009-06-01 00:20:23 +0000 | [diff] [blame] | 93 | if ((cycles_elapsed >> 6) < cpt) { |
Grant Grundler | 6e5dc42 | 2006-09-10 12:57:55 -0700 | [diff] [blame] | 94 | /* use "cheap" math (add/subtract) instead |
| 95 | * of the more expensive div/mul method |
Grant Grundler | bed583f | 2006-09-08 23:29:22 -0700 | [diff] [blame] | 96 | */ |
Grant Grundler | 6b799d9 | 2006-09-04 13:56:11 -0700 | [diff] [blame] | 97 | cycles_remainder = cycles_elapsed; |
Grant Grundler | 6e5dc42 | 2006-09-10 12:57:55 -0700 | [diff] [blame] | 98 | while (cycles_remainder > cpt) { |
| 99 | cycles_remainder -= cpt; |
Matthew Wilcox | 1604f31 | 2006-10-04 15:12:52 -0600 | [diff] [blame] | 100 | ticks_elapsed++; |
Grant Grundler | 6e5dc42 | 2006-09-10 12:57:55 -0700 | [diff] [blame] | 101 | } |
Grant Grundler | 6b799d9 | 2006-09-04 13:56:11 -0700 | [diff] [blame] | 102 | } else { |
Grant Grundler | 84be31b | 2009-06-01 00:20:23 +0000 | [diff] [blame] | 103 | /* TODO: Reduce this to one fdiv op */ |
Grant Grundler | 6e5dc42 | 2006-09-10 12:57:55 -0700 | [diff] [blame] | 104 | cycles_remainder = cycles_elapsed % cpt; |
Grant Grundler | 84be31b | 2009-06-01 00:20:23 +0000 | [diff] [blame] | 105 | ticks_elapsed += cycles_elapsed / cpt; |
Grant Grundler | bed583f | 2006-09-08 23:29:22 -0700 | [diff] [blame] | 106 | } |
| 107 | |
Grant Grundler | 6e5dc42 | 2006-09-10 12:57:55 -0700 | [diff] [blame] | 108 | /* convert from "division remainder" to "remainder of clock tick" */ |
| 109 | cycles_remainder = cpt - cycles_remainder; |
Grant Grundler | bed583f | 2006-09-08 23:29:22 -0700 | [diff] [blame] | 110 | |
| 111 | /* Determine when (in CR16 cycles) next IT interrupt will fire. |
| 112 | * We want IT to fire modulo clocktick even if we miss/skip some. |
| 113 | * But those interrupts don't in fact get delivered that regularly. |
| 114 | */ |
Grant Grundler | 6e5dc42 | 2006-09-10 12:57:55 -0700 | [diff] [blame] | 115 | next_tick = now + cycles_remainder; |
| 116 | |
Matthew Wilcox | c7753f1 | 2006-10-07 06:01:11 -0600 | [diff] [blame] | 117 | cpuinfo->it_value = next_tick; |
Grant Grundler | 6b799d9 | 2006-09-04 13:56:11 -0700 | [diff] [blame] | 118 | |
Grant Grundler | 84be31b | 2009-06-01 00:20:23 +0000 | [diff] [blame] | 119 | /* Program the IT when to deliver the next interrupt. |
| 120 | * Only bottom 32-bits of next_tick are writable in CR16! |
Grant Grundler | 6e5dc42 | 2006-09-10 12:57:55 -0700 | [diff] [blame] | 121 | */ |
Grant Grundler | 6b799d9 | 2006-09-04 13:56:11 -0700 | [diff] [blame] | 122 | mtctl(next_tick, 16); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 123 | |
Helge Deller | 54b66800 | 2016-04-20 21:34:15 +0200 | [diff] [blame] | 124 | #if !defined(CONFIG_64BIT) |
| 125 | /* check for overflow on a 32bit kernel (every ~4 seconds). */ |
| 126 | if (unlikely(next_tick < now)) |
| 127 | this_cpu_inc(cr16_high_32_bits); |
| 128 | #endif |
| 129 | |
Grant Grundler | 84be31b | 2009-06-01 00:20:23 +0000 | [diff] [blame] | 130 | /* Skip one clocktick on purpose if we missed next_tick. |
| 131 | * The new CR16 must be "later" than current CR16 otherwise |
| 132 | * itimer would not fire until CR16 wrapped - e.g 4 seconds |
| 133 | * later on a 1Ghz processor. We'll account for the missed |
| 134 | * tick on the next timer interrupt. |
| 135 | * |
| 136 | * "next_tick - now" will always give the difference regardless |
| 137 | * if one or the other wrapped. If "now" is "bigger" we'll end up |
| 138 | * with a very large unsigned number. |
| 139 | */ |
| 140 | now2 = mfctl(16); |
| 141 | if (next_tick - now2 > cpt) |
| 142 | mtctl(next_tick+cpt, 16); |
| 143 | |
| 144 | #if 1 |
| 145 | /* |
| 146 | * GGG: DEBUG code for how many cycles programming CR16 used. |
| 147 | */ |
| 148 | if (unlikely(now2 - now > 0x3000)) /* 12K cycles */ |
| 149 | printk (KERN_CRIT "timer_interrupt(CPU %d): SLOW! 0x%lx cycles!" |
| 150 | " cyc %lX rem %lX " |
| 151 | " next/now %lX/%lX\n", |
| 152 | cpu, now2 - now, cycles_elapsed, cycles_remainder, |
| 153 | next_tick, now ); |
| 154 | #endif |
| 155 | |
| 156 | /* Can we differentiate between "early CR16" (aka Scenario 1) and |
| 157 | * "long delay" (aka Scenario 3)? I don't think so. |
| 158 | * |
| 159 | * Timer_interrupt will be delivered at least a few hundred cycles |
| 160 | * after the IT fires. But it's arbitrary how much time passes |
| 161 | * before we call it "late". I've picked one second. |
| 162 | * |
| 163 | * It's important NO printk's are between reading CR16 and |
| 164 | * setting up the next value. May introduce huge variance. |
| 165 | */ |
| 166 | if (unlikely(ticks_elapsed > HZ)) { |
| 167 | /* Scenario 3: very long delay? bad in any case */ |
| 168 | printk (KERN_CRIT "timer_interrupt(CPU %d): delayed!" |
| 169 | " cycles %lX rem %lX " |
| 170 | " next/now %lX/%lX\n", |
| 171 | cpu, |
| 172 | cycles_elapsed, cycles_remainder, |
| 173 | next_tick, now ); |
| 174 | } |
Grant Grundler | 6e5dc42 | 2006-09-10 12:57:55 -0700 | [diff] [blame] | 175 | |
| 176 | /* Done mucking with unreliable delivery of interrupts. |
| 177 | * Go do system house keeping. |
Grant Grundler | bed583f | 2006-09-08 23:29:22 -0700 | [diff] [blame] | 178 | */ |
Matthew Wilcox | c7753f1 | 2006-10-07 06:01:11 -0600 | [diff] [blame] | 179 | |
| 180 | if (!--cpuinfo->prof_counter) { |
| 181 | cpuinfo->prof_counter = cpuinfo->prof_multiplier; |
| 182 | update_process_times(user_mode(get_irq_regs())); |
| 183 | } |
| 184 | |
Torben Hohn | bb1dfc1 | 2011-01-27 16:00:17 +0100 | [diff] [blame] | 185 | if (cpu == 0) |
| 186 | xtime_update(ticks_elapsed); |
Grant Grundler | 6e5dc42 | 2006-09-10 12:57:55 -0700 | [diff] [blame] | 187 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 188 | return IRQ_HANDLED; |
| 189 | } |
| 190 | |
Randolph Chung | 5cd55b0 | 2005-10-21 22:42:18 -0400 | [diff] [blame] | 191 | |
| 192 | unsigned long profile_pc(struct pt_regs *regs) |
| 193 | { |
| 194 | unsigned long pc = instruction_pointer(regs); |
| 195 | |
| 196 | if (regs->gr[0] & PSW_N) |
| 197 | pc -= 4; |
| 198 | |
| 199 | #ifdef CONFIG_SMP |
| 200 | if (in_lock_functions(pc)) |
| 201 | pc = regs->gr[2]; |
| 202 | #endif |
| 203 | |
| 204 | return pc; |
| 205 | } |
| 206 | EXPORT_SYMBOL(profile_pc); |
| 207 | |
| 208 | |
Helge Deller | 12df29b | 2007-01-02 23:54:16 +0100 | [diff] [blame] | 209 | /* clock source code */ |
| 210 | |
Coly Li | ebc30a0 | 2009-04-30 22:43:46 +0000 | [diff] [blame] | 211 | static cycle_t read_cr16(struct clocksource *cs) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 212 | { |
Helge Deller | 12df29b | 2007-01-02 23:54:16 +0100 | [diff] [blame] | 213 | return get_cycles(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 214 | } |
| 215 | |
Helge Deller | 12df29b | 2007-01-02 23:54:16 +0100 | [diff] [blame] | 216 | static struct clocksource clocksource_cr16 = { |
| 217 | .name = "cr16", |
| 218 | .rating = 300, |
| 219 | .read = read_cr16, |
| 220 | .mask = CLOCKSOURCE_MASK(BITS_PER_LONG), |
Kyle McMartin | 87c8174 | 2007-02-26 20:15:18 -0500 | [diff] [blame] | 221 | .flags = CLOCK_SOURCE_IS_CONTINUOUS, |
Helge Deller | 12df29b | 2007-01-02 23:54:16 +0100 | [diff] [blame] | 222 | }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 223 | |
Grant Grundler | 56f335c | 2006-09-03 00:02:16 -0700 | [diff] [blame] | 224 | void __init start_cpu_itimer(void) |
| 225 | { |
| 226 | unsigned int cpu = smp_processor_id(); |
| 227 | unsigned long next_tick = mfctl(16) + clocktick; |
| 228 | |
Helge Deller | 54b66800 | 2016-04-20 21:34:15 +0200 | [diff] [blame] | 229 | #if defined(CONFIG_HAVE_UNSTABLE_SCHED_CLOCK) && defined(CONFIG_64BIT) |
| 230 | /* With multiple 64bit CPUs online, the cr16's are not syncronized. */ |
| 231 | if (cpu != 0) |
| 232 | clear_sched_clock_stable(); |
| 233 | #endif |
| 234 | |
Grant Grundler | 56f335c | 2006-09-03 00:02:16 -0700 | [diff] [blame] | 235 | mtctl(next_tick, 16); /* kick off Interval Timer (CR16) */ |
| 236 | |
Helge Deller | ef017be | 2008-12-31 03:12:10 +0000 | [diff] [blame] | 237 | per_cpu(cpu_data, cpu).it_value = next_tick; |
Grant Grundler | 56f335c | 2006-09-03 00:02:16 -0700 | [diff] [blame] | 238 | } |
| 239 | |
Arnd Bergmann | ca6da80 | 2016-05-30 20:57:55 +0200 | [diff] [blame] | 240 | #if IS_ENABLED(CONFIG_RTC_DRV_GENERIC) |
| 241 | static int rtc_generic_get_time(struct device *dev, struct rtc_time *tm) |
| 242 | { |
| 243 | struct pdc_tod tod_data; |
| 244 | |
| 245 | memset(tm, 0, sizeof(*tm)); |
| 246 | if (pdc_tod_read(&tod_data) < 0) |
| 247 | return -EOPNOTSUPP; |
| 248 | |
| 249 | /* we treat tod_sec as unsigned, so this can work until year 2106 */ |
| 250 | rtc_time64_to_tm(tod_data.tod_sec, tm); |
| 251 | return rtc_valid_tm(tm); |
| 252 | } |
| 253 | |
| 254 | static int rtc_generic_set_time(struct device *dev, struct rtc_time *tm) |
| 255 | { |
| 256 | time64_t secs = rtc_tm_to_time64(tm); |
| 257 | |
| 258 | if (pdc_tod_set(secs, 0) < 0) |
| 259 | return -EOPNOTSUPP; |
| 260 | |
| 261 | return 0; |
| 262 | } |
| 263 | |
| 264 | static const struct rtc_class_ops rtc_generic_ops = { |
| 265 | .read_time = rtc_generic_get_time, |
| 266 | .set_time = rtc_generic_set_time, |
| 267 | }; |
| 268 | |
Kyle McMartin | 9eb1686 | 2008-09-10 14:24:07 +0000 | [diff] [blame] | 269 | static int __init rtc_init(void) |
| 270 | { |
Helge Deller | 6dc0dcd | 2015-09-08 17:50:03 +0200 | [diff] [blame] | 271 | struct platform_device *pdev; |
Kyle McMartin | 9eb1686 | 2008-09-10 14:24:07 +0000 | [diff] [blame] | 272 | |
Arnd Bergmann | ca6da80 | 2016-05-30 20:57:55 +0200 | [diff] [blame] | 273 | pdev = platform_device_register_data(NULL, "rtc-generic", -1, |
| 274 | &rtc_generic_ops, |
| 275 | sizeof(rtc_generic_ops)); |
| 276 | |
Helge Deller | 6dc0dcd | 2015-09-08 17:50:03 +0200 | [diff] [blame] | 277 | return PTR_ERR_OR_ZERO(pdev); |
Kyle McMartin | 9eb1686 | 2008-09-10 14:24:07 +0000 | [diff] [blame] | 278 | } |
Helge Deller | 6dc0dcd | 2015-09-08 17:50:03 +0200 | [diff] [blame] | 279 | device_initcall(rtc_init); |
Arnd Bergmann | ca6da80 | 2016-05-30 20:57:55 +0200 | [diff] [blame] | 280 | #endif |
Kyle McMartin | 9eb1686 | 2008-09-10 14:24:07 +0000 | [diff] [blame] | 281 | |
john stultz | c601852 | 2009-12-23 04:14:03 +0000 | [diff] [blame] | 282 | void read_persistent_clock(struct timespec *ts) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 283 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 284 | static struct pdc_tod tod_data; |
john stultz | c601852 | 2009-12-23 04:14:03 +0000 | [diff] [blame] | 285 | if (pdc_tod_read(&tod_data) == 0) { |
| 286 | ts->tv_sec = tod_data.tod_sec; |
| 287 | ts->tv_nsec = tod_data.tod_usec * 1000; |
| 288 | } else { |
| 289 | printk(KERN_ERR "Error reading tod clock\n"); |
| 290 | ts->tv_sec = 0; |
| 291 | ts->tv_nsec = 0; |
| 292 | } |
| 293 | } |
| 294 | |
Helge Deller | 54b66800 | 2016-04-20 21:34:15 +0200 | [diff] [blame] | 295 | |
| 296 | /* |
| 297 | * sched_clock() framework |
| 298 | */ |
| 299 | |
| 300 | static u32 cyc2ns_mul __read_mostly; |
| 301 | static u32 cyc2ns_shift __read_mostly; |
| 302 | |
| 303 | u64 sched_clock(void) |
| 304 | { |
| 305 | u64 now; |
| 306 | |
| 307 | /* Get current cycle counter (Control Register 16). */ |
| 308 | #ifdef CONFIG_64BIT |
| 309 | now = mfctl(16); |
| 310 | #else |
| 311 | now = mfctl(16) + (((u64) this_cpu_read(cr16_high_32_bits)) << 32); |
| 312 | #endif |
| 313 | |
| 314 | /* return the value in ns (cycles_2_ns) */ |
| 315 | return mul_u64_u32_shr(now, cyc2ns_mul, cyc2ns_shift); |
| 316 | } |
| 317 | |
| 318 | |
| 319 | /* |
| 320 | * timer interrupt and sched_clock() initialization |
| 321 | */ |
| 322 | |
john stultz | c601852 | 2009-12-23 04:14:03 +0000 | [diff] [blame] | 323 | void __init time_init(void) |
| 324 | { |
Helge Deller | 12df29b | 2007-01-02 23:54:16 +0100 | [diff] [blame] | 325 | unsigned long current_cr16_khz; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 326 | |
Helge Deller | 54b66800 | 2016-04-20 21:34:15 +0200 | [diff] [blame] | 327 | current_cr16_khz = PAGE0->mem_10msec/10; /* kHz */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 328 | clocktick = (100 * PAGE0->mem_10msec) / HZ; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 329 | |
Helge Deller | 54b66800 | 2016-04-20 21:34:15 +0200 | [diff] [blame] | 330 | /* calculate mult/shift values for cr16 */ |
| 331 | clocks_calc_mult_shift(&cyc2ns_mul, &cyc2ns_shift, current_cr16_khz, |
| 332 | NSEC_PER_MSEC, 0); |
| 333 | |
Grant Grundler | 56f335c | 2006-09-03 00:02:16 -0700 | [diff] [blame] | 334 | start_cpu_itimer(); /* get CPU 0 started */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 335 | |
Helge Deller | 12df29b | 2007-01-02 23:54:16 +0100 | [diff] [blame] | 336 | /* register at clocksource framework */ |
John Stultz | 63e4963 | 2010-04-26 20:23:50 -0700 | [diff] [blame] | 337 | clocksource_register_khz(&clocksource_cr16, current_cr16_khz); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 338 | } |