Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2 | * Common time routines among all ppc machines. |
| 3 | * |
| 4 | * Written by Cort Dougan (cort@cs.nmt.edu) to merge |
| 5 | * Paul Mackerras' version and mine for PReP and Pmac. |
| 6 | * MPC8xx/MBX changes by Dan Malek (dmalek@jlc.net). |
| 7 | * Converted for 64-bit by Mike Corrigan (mikejc@us.ibm.com) |
| 8 | * |
| 9 | * First round of bugfixes by Gabriel Paubert (paubert@iram.es) |
| 10 | * to make clock more stable (2.4.0-test5). The only thing |
| 11 | * that this code assumes is that the timebases have been synchronized |
| 12 | * by firmware on SMP and are never stopped (never do sleep |
| 13 | * on SMP then, nap and doze are OK). |
| 14 | * |
| 15 | * Speeded up do_gettimeofday by getting rid of references to |
| 16 | * xtime (which required locks for consistency). (mikejc@us.ibm.com) |
| 17 | * |
| 18 | * TODO (not necessarily in this file): |
| 19 | * - improve precision and reproducibility of timebase frequency |
| 20 | * measurement at boot time. (for iSeries, we calibrate the timebase |
| 21 | * against the Titan chip's clock.) |
| 22 | * - for astronomical applications: add a new function to get |
| 23 | * non ambiguous timestamps even around leap seconds. This needs |
| 24 | * a new timestamp format and a good name. |
| 25 | * |
| 26 | * 1997-09-10 Updated NTP code according to technical memorandum Jan '96 |
| 27 | * "A Kernel Model for Precision Timekeeping" by Dave Mills |
| 28 | * |
| 29 | * This program is free software; you can redistribute it and/or |
| 30 | * modify it under the terms of the GNU General Public License |
| 31 | * as published by the Free Software Foundation; either version |
| 32 | * 2 of the License, or (at your option) any later version. |
| 33 | */ |
| 34 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 35 | #include <linux/errno.h> |
| 36 | #include <linux/module.h> |
| 37 | #include <linux/sched.h> |
| 38 | #include <linux/kernel.h> |
| 39 | #include <linux/param.h> |
| 40 | #include <linux/string.h> |
| 41 | #include <linux/mm.h> |
| 42 | #include <linux/interrupt.h> |
| 43 | #include <linux/timex.h> |
| 44 | #include <linux/kernel_stat.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 45 | #include <linux/time.h> |
| 46 | #include <linux/init.h> |
| 47 | #include <linux/profile.h> |
| 48 | #include <linux/cpu.h> |
| 49 | #include <linux/security.h> |
Paul Mackerras | f2783c1 | 2005-10-20 09:23:26 +1000 | [diff] [blame] | 50 | #include <linux/percpu.h> |
| 51 | #include <linux/rtc.h> |
Paul Mackerras | 092b8f3 | 2006-02-20 10:38:56 +1100 | [diff] [blame] | 52 | #include <linux/jiffies.h> |
Paul Mackerras | c6622f6 | 2006-02-24 10:06:59 +1100 | [diff] [blame] | 53 | #include <linux/posix-timers.h> |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 54 | #include <linux/irq.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 55 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 56 | #include <asm/io.h> |
| 57 | #include <asm/processor.h> |
| 58 | #include <asm/nvram.h> |
| 59 | #include <asm/cache.h> |
| 60 | #include <asm/machdep.h> |
Paul Mackerras | f2783c1 | 2005-10-20 09:23:26 +1000 | [diff] [blame] | 61 | #include <asm/uaccess.h> |
| 62 | #include <asm/time.h> |
| 63 | #include <asm/prom.h> |
| 64 | #include <asm/irq.h> |
| 65 | #include <asm/div64.h> |
Paul Mackerras | 2249ca9 | 2005-11-07 13:18:13 +1100 | [diff] [blame] | 66 | #include <asm/smp.h> |
Benjamin Herrenschmidt | a7f290d | 2005-11-11 21:15:21 +1100 | [diff] [blame] | 67 | #include <asm/vdso_datapage.h> |
Paul Mackerras | f2783c1 | 2005-10-20 09:23:26 +1000 | [diff] [blame] | 68 | #include <asm/firmware.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 69 | #ifdef CONFIG_PPC_ISERIES |
Kelly Daly | 8875ccf | 2005-11-02 14:13:34 +1100 | [diff] [blame] | 70 | #include <asm/iseries/it_lp_queue.h> |
Kelly Daly | 8021b8a | 2005-11-02 11:41:12 +1100 | [diff] [blame] | 71 | #include <asm/iseries/hv_call_xm.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 72 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 73 | |
Tony Breeds | 4a4cfe3 | 2007-09-22 07:35:52 +1000 | [diff] [blame] | 74 | /* powerpc clocksource/clockevent code */ |
| 75 | |
Tony Breeds | d831d0b | 2007-09-21 13:26:03 +1000 | [diff] [blame] | 76 | #include <linux/clockchips.h> |
Tony Breeds | 4a4cfe3 | 2007-09-22 07:35:52 +1000 | [diff] [blame] | 77 | #include <linux/clocksource.h> |
| 78 | |
| 79 | static cycle_t rtc_read(void); |
| 80 | static struct clocksource clocksource_rtc = { |
| 81 | .name = "rtc", |
| 82 | .rating = 400, |
| 83 | .flags = CLOCK_SOURCE_IS_CONTINUOUS, |
| 84 | .mask = CLOCKSOURCE_MASK(64), |
| 85 | .shift = 22, |
| 86 | .mult = 0, /* To be filled in */ |
| 87 | .read = rtc_read, |
| 88 | }; |
| 89 | |
| 90 | static cycle_t timebase_read(void); |
| 91 | static struct clocksource clocksource_timebase = { |
| 92 | .name = "timebase", |
| 93 | .rating = 400, |
| 94 | .flags = CLOCK_SOURCE_IS_CONTINUOUS, |
| 95 | .mask = CLOCKSOURCE_MASK(64), |
| 96 | .shift = 22, |
| 97 | .mult = 0, /* To be filled in */ |
| 98 | .read = timebase_read, |
| 99 | }; |
| 100 | |
Tony Breeds | d831d0b | 2007-09-21 13:26:03 +1000 | [diff] [blame] | 101 | #define DECREMENTER_MAX 0x7fffffff |
| 102 | |
| 103 | static int decrementer_set_next_event(unsigned long evt, |
| 104 | struct clock_event_device *dev); |
| 105 | static void decrementer_set_mode(enum clock_event_mode mode, |
| 106 | struct clock_event_device *dev); |
| 107 | |
| 108 | static struct clock_event_device decrementer_clockevent = { |
| 109 | .name = "decrementer", |
| 110 | .rating = 200, |
Paul Mackerras | cdec12a | 2007-10-11 21:46:45 +1000 | [diff] [blame] | 111 | .shift = 16, |
Tony Breeds | d831d0b | 2007-09-21 13:26:03 +1000 | [diff] [blame] | 112 | .mult = 0, /* To be filled in */ |
| 113 | .irq = 0, |
| 114 | .set_next_event = decrementer_set_next_event, |
| 115 | .set_mode = decrementer_set_mode, |
| 116 | .features = CLOCK_EVT_FEAT_ONESHOT, |
| 117 | }; |
| 118 | |
| 119 | static DEFINE_PER_CPU(struct clock_event_device, decrementers); |
| 120 | void init_decrementer_clockevent(void); |
Paul Mackerras | d968014 | 2007-10-09 09:59:17 +1000 | [diff] [blame] | 121 | static DEFINE_PER_CPU(u64, decrementer_next_tb); |
Tony Breeds | d831d0b | 2007-09-21 13:26:03 +1000 | [diff] [blame] | 122 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 123 | #ifdef CONFIG_PPC_ISERIES |
Tony Breeds | 71712b4 | 2007-06-22 16:54:30 +1000 | [diff] [blame] | 124 | static unsigned long __initdata iSeries_recal_titan; |
| 125 | static signed long __initdata iSeries_recal_tb; |
Tony Breeds | 4a4cfe3 | 2007-09-22 07:35:52 +1000 | [diff] [blame] | 126 | |
| 127 | /* Forward declaration is only needed for iSereis compiles */ |
| 128 | void __init clocksource_init(void); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 129 | #endif |
| 130 | |
| 131 | #define XSEC_PER_SEC (1024*1024) |
| 132 | |
Paul Mackerras | f2783c1 | 2005-10-20 09:23:26 +1000 | [diff] [blame] | 133 | #ifdef CONFIG_PPC64 |
| 134 | #define SCALE_XSEC(xsec, max) (((xsec) * max) / XSEC_PER_SEC) |
| 135 | #else |
| 136 | /* compute ((xsec << 12) * max) >> 32 */ |
| 137 | #define SCALE_XSEC(xsec, max) mulhwu((xsec) << 12, max) |
| 138 | #endif |
| 139 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 140 | unsigned long tb_ticks_per_jiffy; |
| 141 | unsigned long tb_ticks_per_usec = 100; /* sane default */ |
| 142 | EXPORT_SYMBOL(tb_ticks_per_usec); |
| 143 | unsigned long tb_ticks_per_sec; |
Paul Mackerras | 2cf82c0 | 2006-02-27 15:41:47 +1100 | [diff] [blame] | 144 | EXPORT_SYMBOL(tb_ticks_per_sec); /* for cputime_t conversions */ |
Paul Mackerras | f2783c1 | 2005-10-20 09:23:26 +1000 | [diff] [blame] | 145 | u64 tb_to_xs; |
| 146 | unsigned tb_to_us; |
Paul Mackerras | 092b8f3 | 2006-02-20 10:38:56 +1100 | [diff] [blame] | 147 | |
Roman Zippel | 19923c1 | 2006-06-26 00:25:18 -0700 | [diff] [blame] | 148 | #define TICKLEN_SCALE TICK_LENGTH_SHIFT |
Paul Mackerras | 092b8f3 | 2006-02-20 10:38:56 +1100 | [diff] [blame] | 149 | u64 last_tick_len; /* units are ns / 2^TICKLEN_SCALE */ |
| 150 | u64 ticklen_to_xs; /* 0.64 fraction */ |
| 151 | |
| 152 | /* If last_tick_len corresponds to about 1/HZ seconds, then |
| 153 | last_tick_len << TICKLEN_SHIFT will be about 2^63. */ |
| 154 | #define TICKLEN_SHIFT (63 - 30 - TICKLEN_SCALE + SHIFT_HZ) |
| 155 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 156 | DEFINE_SPINLOCK(rtc_lock); |
Benjamin Herrenschmidt | 6ae3db1 | 2005-06-27 14:36:35 -0700 | [diff] [blame] | 157 | EXPORT_SYMBOL_GPL(rtc_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 158 | |
Tony Breeds | fc9069fe | 2007-07-04 14:04:31 +1000 | [diff] [blame] | 159 | static u64 tb_to_ns_scale __read_mostly; |
| 160 | static unsigned tb_to_ns_shift __read_mostly; |
| 161 | static unsigned long boot_tb __read_mostly; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 162 | |
| 163 | struct gettimeofday_struct do_gtod; |
| 164 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 165 | extern struct timezone sys_tz; |
Paul Mackerras | f2783c1 | 2005-10-20 09:23:26 +1000 | [diff] [blame] | 166 | static long timezone_offset; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 167 | |
Arnd Bergmann | 10f7e7c | 2005-06-23 09:43:07 +1000 | [diff] [blame] | 168 | unsigned long ppc_proc_freq; |
Bob Nelson | 1474855 | 2007-07-20 21:39:53 +0200 | [diff] [blame] | 169 | EXPORT_SYMBOL(ppc_proc_freq); |
Arnd Bergmann | 10f7e7c | 2005-06-23 09:43:07 +1000 | [diff] [blame] | 170 | unsigned long ppc_tb_freq; |
| 171 | |
Paul Mackerras | eb36c28 | 2006-08-30 16:13:16 +1000 | [diff] [blame] | 172 | static u64 tb_last_jiffy __cacheline_aligned_in_smp; |
| 173 | static DEFINE_PER_CPU(u64, last_jiffy); |
Paul Mackerras | 96c4450 | 2005-10-23 17:14:56 +1000 | [diff] [blame] | 174 | |
Paul Mackerras | c6622f6 | 2006-02-24 10:06:59 +1100 | [diff] [blame] | 175 | #ifdef CONFIG_VIRT_CPU_ACCOUNTING |
| 176 | /* |
| 177 | * Factors for converting from cputime_t (timebase ticks) to |
| 178 | * jiffies, milliseconds, seconds, and clock_t (1/USER_HZ seconds). |
| 179 | * These are all stored as 0.64 fixed-point binary fractions. |
| 180 | */ |
| 181 | u64 __cputime_jiffies_factor; |
Paul Mackerras | 2cf82c0 | 2006-02-27 15:41:47 +1100 | [diff] [blame] | 182 | EXPORT_SYMBOL(__cputime_jiffies_factor); |
Paul Mackerras | c6622f6 | 2006-02-24 10:06:59 +1100 | [diff] [blame] | 183 | u64 __cputime_msec_factor; |
Paul Mackerras | 2cf82c0 | 2006-02-27 15:41:47 +1100 | [diff] [blame] | 184 | EXPORT_SYMBOL(__cputime_msec_factor); |
Paul Mackerras | c6622f6 | 2006-02-24 10:06:59 +1100 | [diff] [blame] | 185 | u64 __cputime_sec_factor; |
Paul Mackerras | 2cf82c0 | 2006-02-27 15:41:47 +1100 | [diff] [blame] | 186 | EXPORT_SYMBOL(__cputime_sec_factor); |
Paul Mackerras | c6622f6 | 2006-02-24 10:06:59 +1100 | [diff] [blame] | 187 | u64 __cputime_clockt_factor; |
Paul Mackerras | 2cf82c0 | 2006-02-27 15:41:47 +1100 | [diff] [blame] | 188 | EXPORT_SYMBOL(__cputime_clockt_factor); |
Paul Mackerras | c6622f6 | 2006-02-24 10:06:59 +1100 | [diff] [blame] | 189 | |
| 190 | static void calc_cputime_factors(void) |
| 191 | { |
| 192 | struct div_result res; |
| 193 | |
| 194 | div128_by_32(HZ, 0, tb_ticks_per_sec, &res); |
| 195 | __cputime_jiffies_factor = res.result_low; |
| 196 | div128_by_32(1000, 0, tb_ticks_per_sec, &res); |
| 197 | __cputime_msec_factor = res.result_low; |
| 198 | div128_by_32(1, 0, tb_ticks_per_sec, &res); |
| 199 | __cputime_sec_factor = res.result_low; |
| 200 | div128_by_32(USER_HZ, 0, tb_ticks_per_sec, &res); |
| 201 | __cputime_clockt_factor = res.result_low; |
| 202 | } |
| 203 | |
| 204 | /* |
| 205 | * Read the PURR on systems that have it, otherwise the timebase. |
| 206 | */ |
| 207 | static u64 read_purr(void) |
| 208 | { |
| 209 | if (cpu_has_feature(CPU_FTR_PURR)) |
| 210 | return mfspr(SPRN_PURR); |
| 211 | return mftb(); |
| 212 | } |
| 213 | |
| 214 | /* |
Michael Neuling | 4603ac1 | 2007-10-18 03:06:37 -0700 | [diff] [blame] | 215 | * Read the SPURR on systems that have it, otherwise the purr |
| 216 | */ |
| 217 | static u64 read_spurr(u64 purr) |
| 218 | { |
| 219 | if (cpu_has_feature(CPU_FTR_SPURR)) |
| 220 | return mfspr(SPRN_SPURR); |
| 221 | return purr; |
| 222 | } |
| 223 | |
| 224 | /* |
Paul Mackerras | c6622f6 | 2006-02-24 10:06:59 +1100 | [diff] [blame] | 225 | * Account time for a transition between system, hard irq |
| 226 | * or soft irq state. |
| 227 | */ |
| 228 | void account_system_vtime(struct task_struct *tsk) |
| 229 | { |
Michael Neuling | 4603ac1 | 2007-10-18 03:06:37 -0700 | [diff] [blame] | 230 | u64 now, nowscaled, delta, deltascaled; |
Paul Mackerras | c6622f6 | 2006-02-24 10:06:59 +1100 | [diff] [blame] | 231 | unsigned long flags; |
| 232 | |
| 233 | local_irq_save(flags); |
| 234 | now = read_purr(); |
| 235 | delta = now - get_paca()->startpurr; |
| 236 | get_paca()->startpurr = now; |
Michael Neuling | 4603ac1 | 2007-10-18 03:06:37 -0700 | [diff] [blame] | 237 | nowscaled = read_spurr(now); |
| 238 | deltascaled = nowscaled - get_paca()->startspurr; |
| 239 | get_paca()->startspurr = nowscaled; |
Paul Mackerras | c6622f6 | 2006-02-24 10:06:59 +1100 | [diff] [blame] | 240 | if (!in_interrupt()) { |
Michael Neuling | 4603ac1 | 2007-10-18 03:06:37 -0700 | [diff] [blame] | 241 | /* deltascaled includes both user and system time. |
| 242 | * Hence scale it based on the purr ratio to estimate |
| 243 | * the system time */ |
Michael Neuling | 2b46b56 | 2007-11-20 15:18:40 +1100 | [diff] [blame] | 244 | if (get_paca()->user_time) |
| 245 | deltascaled = deltascaled * get_paca()->system_time / |
| 246 | (get_paca()->system_time + get_paca()->user_time); |
Paul Mackerras | c6622f6 | 2006-02-24 10:06:59 +1100 | [diff] [blame] | 247 | delta += get_paca()->system_time; |
| 248 | get_paca()->system_time = 0; |
| 249 | } |
| 250 | account_system_time(tsk, 0, delta); |
Michael Neuling | 4603ac1 | 2007-10-18 03:06:37 -0700 | [diff] [blame] | 251 | get_paca()->purrdelta = delta; |
| 252 | account_system_time_scaled(tsk, deltascaled); |
| 253 | get_paca()->spurrdelta = deltascaled; |
Paul Mackerras | c6622f6 | 2006-02-24 10:06:59 +1100 | [diff] [blame] | 254 | local_irq_restore(flags); |
| 255 | } |
| 256 | |
| 257 | /* |
| 258 | * Transfer the user and system times accumulated in the paca |
| 259 | * by the exception entry and exit code to the generic process |
| 260 | * user and system time records. |
| 261 | * Must be called with interrupts disabled. |
| 262 | */ |
Paul Mackerras | fa13a5a | 2007-11-09 22:39:38 +0100 | [diff] [blame] | 263 | void account_process_tick(struct task_struct *tsk, int user_tick) |
Paul Mackerras | c6622f6 | 2006-02-24 10:06:59 +1100 | [diff] [blame] | 264 | { |
Michael Neuling | 4603ac1 | 2007-10-18 03:06:37 -0700 | [diff] [blame] | 265 | cputime_t utime, utimescaled; |
Paul Mackerras | c6622f6 | 2006-02-24 10:06:59 +1100 | [diff] [blame] | 266 | |
| 267 | utime = get_paca()->user_time; |
| 268 | get_paca()->user_time = 0; |
| 269 | account_user_time(tsk, utime); |
Michael Neuling | 4603ac1 | 2007-10-18 03:06:37 -0700 | [diff] [blame] | 270 | |
| 271 | /* Estimate the scaled utime by scaling the real utime based |
| 272 | * on the last spurr to purr ratio */ |
| 273 | utimescaled = utime * get_paca()->spurrdelta / get_paca()->purrdelta; |
| 274 | get_paca()->spurrdelta = get_paca()->purrdelta = 0; |
| 275 | account_user_time_scaled(tsk, utimescaled); |
Paul Mackerras | c6622f6 | 2006-02-24 10:06:59 +1100 | [diff] [blame] | 276 | } |
| 277 | |
Paul Mackerras | c6622f6 | 2006-02-24 10:06:59 +1100 | [diff] [blame] | 278 | /* |
| 279 | * Stuff for accounting stolen time. |
| 280 | */ |
| 281 | struct cpu_purr_data { |
| 282 | int initialized; /* thread is running */ |
Paul Mackerras | c6622f6 | 2006-02-24 10:06:59 +1100 | [diff] [blame] | 283 | u64 tb; /* last TB value read */ |
| 284 | u64 purr; /* last PURR value read */ |
Michael Neuling | 4603ac1 | 2007-10-18 03:06:37 -0700 | [diff] [blame] | 285 | u64 spurr; /* last SPURR value read */ |
Paul Mackerras | c6622f6 | 2006-02-24 10:06:59 +1100 | [diff] [blame] | 286 | }; |
| 287 | |
Nathan Lynch | df211c8 | 2007-05-23 10:51:25 +1000 | [diff] [blame] | 288 | /* |
| 289 | * Each entry in the cpu_purr_data array is manipulated only by its |
| 290 | * "owner" cpu -- usually in the timer interrupt but also occasionally |
| 291 | * in process context for cpu online. As long as cpus do not touch |
| 292 | * each others' cpu_purr_data, disabling local interrupts is |
| 293 | * sufficient to serialize accesses. |
| 294 | */ |
Paul Mackerras | c6622f6 | 2006-02-24 10:06:59 +1100 | [diff] [blame] | 295 | static DEFINE_PER_CPU(struct cpu_purr_data, cpu_purr_data); |
| 296 | |
| 297 | static void snapshot_tb_and_purr(void *data) |
| 298 | { |
Nathan Lynch | df211c8 | 2007-05-23 10:51:25 +1000 | [diff] [blame] | 299 | unsigned long flags; |
Paul Mackerras | c6622f6 | 2006-02-24 10:06:59 +1100 | [diff] [blame] | 300 | struct cpu_purr_data *p = &__get_cpu_var(cpu_purr_data); |
| 301 | |
Nathan Lynch | df211c8 | 2007-05-23 10:51:25 +1000 | [diff] [blame] | 302 | local_irq_save(flags); |
Benjamin Herrenschmidt | c27da339 | 2007-09-19 14:21:56 +1000 | [diff] [blame] | 303 | p->tb = get_tb_or_rtc(); |
Stephen Rothwell | cbcdb93 | 2006-10-17 23:08:35 +1000 | [diff] [blame] | 304 | p->purr = mfspr(SPRN_PURR); |
Paul Mackerras | c6622f6 | 2006-02-24 10:06:59 +1100 | [diff] [blame] | 305 | wmb(); |
| 306 | p->initialized = 1; |
Nathan Lynch | df211c8 | 2007-05-23 10:51:25 +1000 | [diff] [blame] | 307 | local_irq_restore(flags); |
Paul Mackerras | c6622f6 | 2006-02-24 10:06:59 +1100 | [diff] [blame] | 308 | } |
| 309 | |
| 310 | /* |
| 311 | * Called during boot when all cpus have come up. |
| 312 | */ |
| 313 | void snapshot_timebases(void) |
| 314 | { |
Paul Mackerras | c6622f6 | 2006-02-24 10:06:59 +1100 | [diff] [blame] | 315 | if (!cpu_has_feature(CPU_FTR_PURR)) |
| 316 | return; |
Paul Mackerras | c6622f6 | 2006-02-24 10:06:59 +1100 | [diff] [blame] | 317 | on_each_cpu(snapshot_tb_and_purr, NULL, 0, 1); |
| 318 | } |
| 319 | |
Nathan Lynch | df211c8 | 2007-05-23 10:51:25 +1000 | [diff] [blame] | 320 | /* |
| 321 | * Must be called with interrupts disabled. |
| 322 | */ |
Paul Mackerras | c6622f6 | 2006-02-24 10:06:59 +1100 | [diff] [blame] | 323 | void calculate_steal_time(void) |
| 324 | { |
Stephen Rothwell | cbcdb93 | 2006-10-17 23:08:35 +1000 | [diff] [blame] | 325 | u64 tb, purr; |
Paul Mackerras | c6622f6 | 2006-02-24 10:06:59 +1100 | [diff] [blame] | 326 | s64 stolen; |
Stephen Rothwell | cbcdb93 | 2006-10-17 23:08:35 +1000 | [diff] [blame] | 327 | struct cpu_purr_data *pme; |
Paul Mackerras | c6622f6 | 2006-02-24 10:06:59 +1100 | [diff] [blame] | 328 | |
| 329 | if (!cpu_has_feature(CPU_FTR_PURR)) |
| 330 | return; |
Stephen Rothwell | cbcdb93 | 2006-10-17 23:08:35 +1000 | [diff] [blame] | 331 | pme = &per_cpu(cpu_purr_data, smp_processor_id()); |
Paul Mackerras | c6622f6 | 2006-02-24 10:06:59 +1100 | [diff] [blame] | 332 | if (!pme->initialized) |
| 333 | return; /* this can happen in early boot */ |
Paul Mackerras | c6622f6 | 2006-02-24 10:06:59 +1100 | [diff] [blame] | 334 | tb = mftb(); |
Stephen Rothwell | cbcdb93 | 2006-10-17 23:08:35 +1000 | [diff] [blame] | 335 | purr = mfspr(SPRN_PURR); |
| 336 | stolen = (tb - pme->tb) - (purr - pme->purr); |
| 337 | if (stolen > 0) |
Paul Mackerras | c6622f6 | 2006-02-24 10:06:59 +1100 | [diff] [blame] | 338 | account_steal_time(current, stolen); |
Paul Mackerras | c6622f6 | 2006-02-24 10:06:59 +1100 | [diff] [blame] | 339 | pme->tb = tb; |
| 340 | pme->purr = purr; |
Paul Mackerras | c6622f6 | 2006-02-24 10:06:59 +1100 | [diff] [blame] | 341 | } |
| 342 | |
Michael Neuling | 4cefebb1 | 2007-06-08 13:18:50 +1000 | [diff] [blame] | 343 | #ifdef CONFIG_PPC_SPLPAR |
Paul Mackerras | c6622f6 | 2006-02-24 10:06:59 +1100 | [diff] [blame] | 344 | /* |
| 345 | * Must be called before the cpu is added to the online map when |
| 346 | * a cpu is being brought up at runtime. |
| 347 | */ |
| 348 | static void snapshot_purr(void) |
| 349 | { |
Stephen Rothwell | cbcdb93 | 2006-10-17 23:08:35 +1000 | [diff] [blame] | 350 | struct cpu_purr_data *pme; |
Paul Mackerras | c6622f6 | 2006-02-24 10:06:59 +1100 | [diff] [blame] | 351 | unsigned long flags; |
| 352 | |
| 353 | if (!cpu_has_feature(CPU_FTR_PURR)) |
| 354 | return; |
Nathan Lynch | df211c8 | 2007-05-23 10:51:25 +1000 | [diff] [blame] | 355 | local_irq_save(flags); |
Stephen Rothwell | cbcdb93 | 2006-10-17 23:08:35 +1000 | [diff] [blame] | 356 | pme = &per_cpu(cpu_purr_data, smp_processor_id()); |
Stephen Rothwell | cbcdb93 | 2006-10-17 23:08:35 +1000 | [diff] [blame] | 357 | pme->tb = mftb(); |
| 358 | pme->purr = mfspr(SPRN_PURR); |
Paul Mackerras | c6622f6 | 2006-02-24 10:06:59 +1100 | [diff] [blame] | 359 | pme->initialized = 1; |
Nathan Lynch | df211c8 | 2007-05-23 10:51:25 +1000 | [diff] [blame] | 360 | local_irq_restore(flags); |
Paul Mackerras | c6622f6 | 2006-02-24 10:06:59 +1100 | [diff] [blame] | 361 | } |
| 362 | |
| 363 | #endif /* CONFIG_PPC_SPLPAR */ |
| 364 | |
| 365 | #else /* ! CONFIG_VIRT_CPU_ACCOUNTING */ |
| 366 | #define calc_cputime_factors() |
Paul Mackerras | c6622f6 | 2006-02-24 10:06:59 +1100 | [diff] [blame] | 367 | #define calculate_steal_time() do { } while (0) |
| 368 | #endif |
| 369 | |
| 370 | #if !(defined(CONFIG_VIRT_CPU_ACCOUNTING) && defined(CONFIG_PPC_SPLPAR)) |
| 371 | #define snapshot_purr() do { } while (0) |
| 372 | #endif |
| 373 | |
| 374 | /* |
| 375 | * Called when a cpu comes up after the system has finished booting, |
| 376 | * i.e. as a result of a hotplug cpu action. |
| 377 | */ |
| 378 | void snapshot_timebase(void) |
| 379 | { |
Benjamin Herrenschmidt | c27da339 | 2007-09-19 14:21:56 +1000 | [diff] [blame] | 380 | __get_cpu_var(last_jiffy) = get_tb_or_rtc(); |
Paul Mackerras | c6622f6 | 2006-02-24 10:06:59 +1100 | [diff] [blame] | 381 | snapshot_purr(); |
| 382 | } |
| 383 | |
Paul Mackerras | 6defa38 | 2005-11-18 13:44:17 +1100 | [diff] [blame] | 384 | void __delay(unsigned long loops) |
| 385 | { |
| 386 | unsigned long start; |
| 387 | int diff; |
| 388 | |
| 389 | if (__USE_RTC()) { |
| 390 | start = get_rtcl(); |
| 391 | do { |
| 392 | /* the RTCL register wraps at 1000000000 */ |
| 393 | diff = get_rtcl() - start; |
| 394 | if (diff < 0) |
| 395 | diff += 1000000000; |
| 396 | } while (diff < loops); |
| 397 | } else { |
| 398 | start = get_tbl(); |
| 399 | while (get_tbl() - start < loops) |
| 400 | HMT_low(); |
| 401 | HMT_medium(); |
| 402 | } |
| 403 | } |
| 404 | EXPORT_SYMBOL(__delay); |
| 405 | |
| 406 | void udelay(unsigned long usecs) |
| 407 | { |
| 408 | __delay(tb_ticks_per_usec * usecs); |
| 409 | } |
| 410 | EXPORT_SYMBOL(udelay); |
| 411 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 412 | |
Paul Mackerras | f2783c1 | 2005-10-20 09:23:26 +1000 | [diff] [blame] | 413 | /* |
| 414 | * There are two copies of tb_to_xs and stamp_xsec so that no |
| 415 | * lock is needed to access and use these values in |
| 416 | * do_gettimeofday. We alternate the copies and as long as a |
| 417 | * reasonable time elapses between changes, there will never |
| 418 | * be inconsistent values. ntpd has a minimum of one minute |
| 419 | * between updates. |
| 420 | */ |
| 421 | static inline void update_gtod(u64 new_tb_stamp, u64 new_stamp_xsec, |
Paul Mackerras | 5d14a18 | 2005-10-20 22:33:06 +1000 | [diff] [blame] | 422 | u64 new_tb_to_xs) |
Paul Mackerras | f2783c1 | 2005-10-20 09:23:26 +1000 | [diff] [blame] | 423 | { |
| 424 | unsigned temp_idx; |
| 425 | struct gettimeofday_vars *temp_varp; |
| 426 | |
| 427 | temp_idx = (do_gtod.var_idx == 0); |
| 428 | temp_varp = &do_gtod.vars[temp_idx]; |
| 429 | |
| 430 | temp_varp->tb_to_xs = new_tb_to_xs; |
| 431 | temp_varp->tb_orig_stamp = new_tb_stamp; |
| 432 | temp_varp->stamp_xsec = new_stamp_xsec; |
| 433 | smp_mb(); |
| 434 | do_gtod.varp = temp_varp; |
| 435 | do_gtod.var_idx = temp_idx; |
| 436 | |
Paul Mackerras | f2783c1 | 2005-10-20 09:23:26 +1000 | [diff] [blame] | 437 | /* |
| 438 | * tb_update_count is used to allow the userspace gettimeofday code |
| 439 | * to assure itself that it sees a consistent view of the tb_to_xs and |
| 440 | * stamp_xsec variables. It reads the tb_update_count, then reads |
| 441 | * tb_to_xs and stamp_xsec and then reads tb_update_count again. If |
| 442 | * the two values of tb_update_count match and are even then the |
| 443 | * tb_to_xs and stamp_xsec values are consistent. If not, then it |
| 444 | * loops back and reads them again until this criteria is met. |
Paul Mackerras | 0a45d44 | 2006-03-15 13:47:15 +1100 | [diff] [blame] | 445 | * We expect the caller to have done the first increment of |
| 446 | * vdso_data->tb_update_count already. |
Paul Mackerras | f2783c1 | 2005-10-20 09:23:26 +1000 | [diff] [blame] | 447 | */ |
Benjamin Herrenschmidt | a7f290d | 2005-11-11 21:15:21 +1100 | [diff] [blame] | 448 | vdso_data->tb_orig_stamp = new_tb_stamp; |
| 449 | vdso_data->stamp_xsec = new_stamp_xsec; |
| 450 | vdso_data->tb_to_xs = new_tb_to_xs; |
| 451 | vdso_data->wtom_clock_sec = wall_to_monotonic.tv_sec; |
| 452 | vdso_data->wtom_clock_nsec = wall_to_monotonic.tv_nsec; |
Paul Mackerras | f2783c1 | 2005-10-20 09:23:26 +1000 | [diff] [blame] | 453 | smp_wmb(); |
Benjamin Herrenschmidt | a7f290d | 2005-11-11 21:15:21 +1100 | [diff] [blame] | 454 | ++(vdso_data->tb_update_count); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 455 | } |
| 456 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 457 | #ifdef CONFIG_SMP |
| 458 | unsigned long profile_pc(struct pt_regs *regs) |
| 459 | { |
| 460 | unsigned long pc = instruction_pointer(regs); |
| 461 | |
| 462 | if (in_lock_functions(pc)) |
| 463 | return regs->link; |
| 464 | |
| 465 | return pc; |
| 466 | } |
| 467 | EXPORT_SYMBOL(profile_pc); |
| 468 | #endif |
| 469 | |
| 470 | #ifdef CONFIG_PPC_ISERIES |
| 471 | |
| 472 | /* |
| 473 | * This function recalibrates the timebase based on the 49-bit time-of-day |
| 474 | * value in the Titan chip. The Titan is much more accurate than the value |
| 475 | * returned by the service processor for the timebase frequency. |
| 476 | */ |
| 477 | |
Tony Breeds | 71712b4 | 2007-06-22 16:54:30 +1000 | [diff] [blame] | 478 | static int __init iSeries_tb_recal(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 479 | { |
| 480 | struct div_result divres; |
| 481 | unsigned long titan, tb; |
Tony Breeds | 71712b4 | 2007-06-22 16:54:30 +1000 | [diff] [blame] | 482 | |
| 483 | /* Make sure we only run on iSeries */ |
| 484 | if (!firmware_has_feature(FW_FEATURE_ISERIES)) |
| 485 | return -ENODEV; |
| 486 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 487 | tb = get_tb(); |
| 488 | titan = HvCallXm_loadTod(); |
| 489 | if ( iSeries_recal_titan ) { |
| 490 | unsigned long tb_ticks = tb - iSeries_recal_tb; |
| 491 | unsigned long titan_usec = (titan - iSeries_recal_titan) >> 12; |
| 492 | unsigned long new_tb_ticks_per_sec = (tb_ticks * USEC_PER_SEC)/titan_usec; |
| 493 | unsigned long new_tb_ticks_per_jiffy = (new_tb_ticks_per_sec+(HZ/2))/HZ; |
| 494 | long tick_diff = new_tb_ticks_per_jiffy - tb_ticks_per_jiffy; |
| 495 | char sign = '+'; |
| 496 | /* make sure tb_ticks_per_sec and tb_ticks_per_jiffy are consistent */ |
| 497 | new_tb_ticks_per_sec = new_tb_ticks_per_jiffy * HZ; |
| 498 | |
| 499 | if ( tick_diff < 0 ) { |
| 500 | tick_diff = -tick_diff; |
| 501 | sign = '-'; |
| 502 | } |
| 503 | if ( tick_diff ) { |
| 504 | if ( tick_diff < tb_ticks_per_jiffy/25 ) { |
| 505 | printk( "Titan recalibrate: new tb_ticks_per_jiffy = %lu (%c%ld)\n", |
| 506 | new_tb_ticks_per_jiffy, sign, tick_diff ); |
| 507 | tb_ticks_per_jiffy = new_tb_ticks_per_jiffy; |
| 508 | tb_ticks_per_sec = new_tb_ticks_per_sec; |
Paul Mackerras | c6622f6 | 2006-02-24 10:06:59 +1100 | [diff] [blame] | 509 | calc_cputime_factors(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 510 | div128_by_32( XSEC_PER_SEC, 0, tb_ticks_per_sec, &divres ); |
| 511 | do_gtod.tb_ticks_per_sec = tb_ticks_per_sec; |
| 512 | tb_to_xs = divres.result_low; |
| 513 | do_gtod.varp->tb_to_xs = tb_to_xs; |
Benjamin Herrenschmidt | a7f290d | 2005-11-11 21:15:21 +1100 | [diff] [blame] | 514 | vdso_data->tb_ticks_per_sec = tb_ticks_per_sec; |
| 515 | vdso_data->tb_to_xs = tb_to_xs; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 516 | } |
| 517 | else { |
| 518 | printk( "Titan recalibrate: FAILED (difference > 4 percent)\n" |
| 519 | " new tb_ticks_per_jiffy = %lu\n" |
| 520 | " old tb_ticks_per_jiffy = %lu\n", |
| 521 | new_tb_ticks_per_jiffy, tb_ticks_per_jiffy ); |
| 522 | } |
| 523 | } |
| 524 | } |
| 525 | iSeries_recal_titan = titan; |
| 526 | iSeries_recal_tb = tb; |
Tony Breeds | 71712b4 | 2007-06-22 16:54:30 +1000 | [diff] [blame] | 527 | |
Tony Breeds | 4a4cfe3 | 2007-09-22 07:35:52 +1000 | [diff] [blame] | 528 | /* Called here as now we know accurate values for the timebase */ |
| 529 | clocksource_init(); |
Tony Breeds | 71712b4 | 2007-06-22 16:54:30 +1000 | [diff] [blame] | 530 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 531 | } |
Tony Breeds | 71712b4 | 2007-06-22 16:54:30 +1000 | [diff] [blame] | 532 | late_initcall(iSeries_tb_recal); |
| 533 | |
| 534 | /* Called from platform early init */ |
| 535 | void __init iSeries_time_init_early(void) |
| 536 | { |
| 537 | iSeries_recal_tb = get_tb(); |
| 538 | iSeries_recal_titan = HvCallXm_loadTod(); |
| 539 | } |
| 540 | #endif /* CONFIG_PPC_ISERIES */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 541 | |
| 542 | /* |
| 543 | * For iSeries shared processors, we have to let the hypervisor |
| 544 | * set the hardware decrementer. We set a virtual decrementer |
| 545 | * in the lppaca and call the hypervisor if the virtual |
| 546 | * decrementer is less than the current value in the hardware |
| 547 | * decrementer. (almost always the new decrementer value will |
| 548 | * be greater than the current hardware decementer so the hypervisor |
| 549 | * call will not be needed) |
| 550 | */ |
| 551 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 552 | /* |
| 553 | * timer_interrupt - gets called when the decrementer overflows, |
| 554 | * with interrupts disabled. |
| 555 | */ |
Kumar Gala | c7aeffc | 2005-09-19 09:30:27 -0500 | [diff] [blame] | 556 | void timer_interrupt(struct pt_regs * regs) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 557 | { |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 558 | struct pt_regs *old_regs; |
Paul Mackerras | f2783c1 | 2005-10-20 09:23:26 +1000 | [diff] [blame] | 559 | int cpu = smp_processor_id(); |
Tony Breeds | d831d0b | 2007-09-21 13:26:03 +1000 | [diff] [blame] | 560 | struct clock_event_device *evt = &per_cpu(decrementers, cpu); |
Paul Mackerras | d968014 | 2007-10-09 09:59:17 +1000 | [diff] [blame] | 561 | u64 now; |
Tony Breeds | d831d0b | 2007-09-21 13:26:03 +1000 | [diff] [blame] | 562 | |
| 563 | /* Ensure a positive value is written to the decrementer, or else |
| 564 | * some CPUs will continuue to take decrementer exceptions */ |
| 565 | set_dec(DECREMENTER_MAX); |
Paul Mackerras | f2783c1 | 2005-10-20 09:23:26 +1000 | [diff] [blame] | 566 | |
| 567 | #ifdef CONFIG_PPC32 |
| 568 | if (atomic_read(&ppc_n_lost_interrupts) != 0) |
| 569 | do_IRQ(regs); |
| 570 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 571 | |
Paul Mackerras | d968014 | 2007-10-09 09:59:17 +1000 | [diff] [blame] | 572 | now = get_tb_or_rtc(); |
| 573 | if (now < per_cpu(decrementer_next_tb, cpu)) { |
| 574 | /* not time for this event yet */ |
| 575 | now = per_cpu(decrementer_next_tb, cpu) - now; |
| 576 | if (now <= DECREMENTER_MAX) |
Paul Mackerras | 43875cc | 2007-10-31 22:25:35 +1100 | [diff] [blame] | 577 | set_dec((int)now); |
Paul Mackerras | d968014 | 2007-10-09 09:59:17 +1000 | [diff] [blame] | 578 | return; |
| 579 | } |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 580 | old_regs = set_irq_regs(regs); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 581 | irq_enter(); |
| 582 | |
Paul Mackerras | c6622f6 | 2006-02-24 10:06:59 +1100 | [diff] [blame] | 583 | calculate_steal_time(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 584 | |
Paul Mackerras | f2783c1 | 2005-10-20 09:23:26 +1000 | [diff] [blame] | 585 | #ifdef CONFIG_PPC_ISERIES |
Stephen Rothwell | 501b6d2 | 2006-11-21 15:10:20 +1100 | [diff] [blame] | 586 | if (firmware_has_feature(FW_FEATURE_ISERIES)) |
| 587 | get_lppaca()->int_dword.fields.decr_int = 0; |
Paul Mackerras | f2783c1 | 2005-10-20 09:23:26 +1000 | [diff] [blame] | 588 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 589 | |
Tony Breeds | d831d0b | 2007-09-21 13:26:03 +1000 | [diff] [blame] | 590 | if (evt->event_handler) |
| 591 | evt->event_handler(evt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 592 | |
| 593 | #ifdef CONFIG_PPC_ISERIES |
Stephen Rothwell | 501b6d2 | 2006-11-21 15:10:20 +1100 | [diff] [blame] | 594 | if (firmware_has_feature(FW_FEATURE_ISERIES) && hvlpevent_is_pending()) |
Olaf Hering | 35a84c2 | 2006-10-07 22:08:26 +1000 | [diff] [blame] | 595 | process_hvlpevents(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 596 | #endif |
| 597 | |
Paul Mackerras | f2783c1 | 2005-10-20 09:23:26 +1000 | [diff] [blame] | 598 | #ifdef CONFIG_PPC64 |
Stephen Rothwell | 8d15a3e | 2005-08-03 14:40:16 +1000 | [diff] [blame] | 599 | /* collect purr register values often, for accurate calculations */ |
Stephen Rothwell | 1ababe1 | 2005-08-03 14:35:25 +1000 | [diff] [blame] | 600 | if (firmware_has_feature(FW_FEATURE_SPLPAR)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 601 | struct cpu_usage *cu = &__get_cpu_var(cpu_usage_array); |
| 602 | cu->current_tb = mfspr(SPRN_PURR); |
| 603 | } |
Paul Mackerras | f2783c1 | 2005-10-20 09:23:26 +1000 | [diff] [blame] | 604 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 605 | |
| 606 | irq_exit(); |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 607 | set_irq_regs(old_regs); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 608 | } |
| 609 | |
Paul Mackerras | f2783c1 | 2005-10-20 09:23:26 +1000 | [diff] [blame] | 610 | void wakeup_decrementer(void) |
| 611 | { |
Paul Mackerras | 092b8f3 | 2006-02-20 10:38:56 +1100 | [diff] [blame] | 612 | unsigned long ticks; |
Paul Mackerras | f2783c1 | 2005-10-20 09:23:26 +1000 | [diff] [blame] | 613 | |
Paul Mackerras | f2783c1 | 2005-10-20 09:23:26 +1000 | [diff] [blame] | 614 | /* |
Paul Mackerras | 092b8f3 | 2006-02-20 10:38:56 +1100 | [diff] [blame] | 615 | * The timebase gets saved on sleep and restored on wakeup, |
| 616 | * so all we need to do is to reset the decrementer. |
Paul Mackerras | f2783c1 | 2005-10-20 09:23:26 +1000 | [diff] [blame] | 617 | */ |
Paul Mackerras | 092b8f3 | 2006-02-20 10:38:56 +1100 | [diff] [blame] | 618 | ticks = tb_ticks_since(__get_cpu_var(last_jiffy)); |
| 619 | if (ticks < tb_ticks_per_jiffy) |
| 620 | ticks = tb_ticks_per_jiffy - ticks; |
| 621 | else |
| 622 | ticks = 1; |
| 623 | set_dec(ticks); |
Paul Mackerras | f2783c1 | 2005-10-20 09:23:26 +1000 | [diff] [blame] | 624 | } |
| 625 | |
Paul Mackerras | a5b518e | 2005-10-22 14:55:23 +1000 | [diff] [blame] | 626 | #ifdef CONFIG_SMP |
Paul Mackerras | f2783c1 | 2005-10-20 09:23:26 +1000 | [diff] [blame] | 627 | void __init smp_space_timers(unsigned int max_cpus) |
| 628 | { |
| 629 | int i; |
Paul Mackerras | eb36c28 | 2006-08-30 16:13:16 +1000 | [diff] [blame] | 630 | u64 previous_tb = per_cpu(last_jiffy, boot_cpuid); |
Paul Mackerras | f2783c1 | 2005-10-20 09:23:26 +1000 | [diff] [blame] | 631 | |
Paul Mackerras | cbe62e2 | 2005-11-10 14:28:03 +1100 | [diff] [blame] | 632 | /* make sure tb > per_cpu(last_jiffy, cpu) for all cpus always */ |
| 633 | previous_tb -= tb_ticks_per_jiffy; |
will schmidt | e147ec8 | 2007-05-11 23:34:16 +1000 | [diff] [blame] | 634 | |
KAMEZAWA Hiroyuki | 0e55195 | 2006-03-28 14:50:51 -0800 | [diff] [blame] | 635 | for_each_possible_cpu(i) { |
Paul Mackerras | c6622f6 | 2006-02-24 10:06:59 +1100 | [diff] [blame] | 636 | if (i == boot_cpuid) |
| 637 | continue; |
will schmidt | e147ec8 | 2007-05-11 23:34:16 +1000 | [diff] [blame] | 638 | per_cpu(last_jiffy, i) = previous_tb; |
Paul Mackerras | f2783c1 | 2005-10-20 09:23:26 +1000 | [diff] [blame] | 639 | } |
| 640 | } |
| 641 | #endif |
| 642 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 643 | /* |
| 644 | * Scheduler clock - returns current time in nanosec units. |
| 645 | * |
| 646 | * Note: mulhdu(a, b) (multiply high double unsigned) returns |
| 647 | * the high 64 bits of a * b, i.e. (a * b) >> 64, where a and b |
| 648 | * are 64-bit unsigned numbers. |
| 649 | */ |
| 650 | unsigned long long sched_clock(void) |
| 651 | { |
Paul Mackerras | 96c4450 | 2005-10-23 17:14:56 +1000 | [diff] [blame] | 652 | if (__USE_RTC()) |
| 653 | return get_rtc(); |
Tony Breeds | fc9069fe | 2007-07-04 14:04:31 +1000 | [diff] [blame] | 654 | return mulhdu(get_tb() - boot_tb, tb_to_ns_scale) << tb_to_ns_shift; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 655 | } |
| 656 | |
Anton Blanchard | 0bb474a4 | 2006-06-20 18:47:26 +1000 | [diff] [blame] | 657 | static int __init get_freq(char *name, int cells, unsigned long *val) |
Arnd Bergmann | 10f7e7c | 2005-06-23 09:43:07 +1000 | [diff] [blame] | 658 | { |
| 659 | struct device_node *cpu; |
Jeremy Kerr | a7f67bd | 2006-07-12 15:35:54 +1000 | [diff] [blame] | 660 | const unsigned int *fp; |
Anton Blanchard | 0bb474a4 | 2006-06-20 18:47:26 +1000 | [diff] [blame] | 661 | int found = 0; |
Arnd Bergmann | 10f7e7c | 2005-06-23 09:43:07 +1000 | [diff] [blame] | 662 | |
Anton Blanchard | 0bb474a4 | 2006-06-20 18:47:26 +1000 | [diff] [blame] | 663 | /* The cpu node should have timebase and clock frequency properties */ |
Arnd Bergmann | 10f7e7c | 2005-06-23 09:43:07 +1000 | [diff] [blame] | 664 | cpu = of_find_node_by_type(NULL, "cpu"); |
| 665 | |
Olaf Hering | d8a8188 | 2006-02-04 10:34:56 +0100 | [diff] [blame] | 666 | if (cpu) { |
Stephen Rothwell | e2eb639 | 2007-04-03 22:26:41 +1000 | [diff] [blame] | 667 | fp = of_get_property(cpu, name, NULL); |
Olaf Hering | d8a8188 | 2006-02-04 10:34:56 +0100 | [diff] [blame] | 668 | if (fp) { |
Anton Blanchard | 0bb474a4 | 2006-06-20 18:47:26 +1000 | [diff] [blame] | 669 | found = 1; |
Paul Mackerras | a4dc7ff | 2006-09-19 14:06:27 +1000 | [diff] [blame] | 670 | *val = of_read_ulong(fp, cells); |
Arnd Bergmann | 10f7e7c | 2005-06-23 09:43:07 +1000 | [diff] [blame] | 671 | } |
Anton Blanchard | 0bb474a4 | 2006-06-20 18:47:26 +1000 | [diff] [blame] | 672 | |
| 673 | of_node_put(cpu); |
Arnd Bergmann | 10f7e7c | 2005-06-23 09:43:07 +1000 | [diff] [blame] | 674 | } |
Anton Blanchard | 0bb474a4 | 2006-06-20 18:47:26 +1000 | [diff] [blame] | 675 | |
| 676 | return found; |
| 677 | } |
| 678 | |
| 679 | void __init generic_calibrate_decr(void) |
| 680 | { |
| 681 | ppc_tb_freq = DEFAULT_TB_FREQ; /* hardcoded default */ |
| 682 | |
| 683 | if (!get_freq("ibm,extended-timebase-frequency", 2, &ppc_tb_freq) && |
| 684 | !get_freq("timebase-frequency", 1, &ppc_tb_freq)) { |
| 685 | |
Arnd Bergmann | 10f7e7c | 2005-06-23 09:43:07 +1000 | [diff] [blame] | 686 | printk(KERN_ERR "WARNING: Estimating decrementer frequency " |
| 687 | "(not found)\n"); |
Arnd Bergmann | 10f7e7c | 2005-06-23 09:43:07 +1000 | [diff] [blame] | 688 | } |
Anton Blanchard | 0bb474a4 | 2006-06-20 18:47:26 +1000 | [diff] [blame] | 689 | |
| 690 | ppc_proc_freq = DEFAULT_PROC_FREQ; /* hardcoded default */ |
| 691 | |
| 692 | if (!get_freq("ibm,extended-clock-frequency", 2, &ppc_proc_freq) && |
| 693 | !get_freq("clock-frequency", 1, &ppc_proc_freq)) { |
| 694 | |
| 695 | printk(KERN_ERR "WARNING: Estimating processor frequency " |
| 696 | "(not found)\n"); |
| 697 | } |
| 698 | |
Josh Boyer | aab6929 | 2007-08-20 07:29:11 -0500 | [diff] [blame] | 699 | #if defined(CONFIG_BOOKE) || defined(CONFIG_40x) |
Kumar Gala | 0fd6f71 | 2005-10-25 23:02:59 -0500 | [diff] [blame] | 700 | /* Set the time base to zero */ |
| 701 | mtspr(SPRN_TBWL, 0); |
| 702 | mtspr(SPRN_TBWU, 0); |
| 703 | |
| 704 | /* Clear any pending timer interrupts */ |
| 705 | mtspr(SPRN_TSR, TSR_ENW | TSR_WIS | TSR_DIS | TSR_FIS); |
| 706 | |
| 707 | /* Enable decrementer interrupt */ |
| 708 | mtspr(SPRN_TCR, TCR_DIE); |
| 709 | #endif |
Arnd Bergmann | 10f7e7c | 2005-06-23 09:43:07 +1000 | [diff] [blame] | 710 | } |
Arnd Bergmann | 10f7e7c | 2005-06-23 09:43:07 +1000 | [diff] [blame] | 711 | |
Tony Breeds | aa3be5f | 2007-09-21 13:26:02 +1000 | [diff] [blame] | 712 | int update_persistent_clock(struct timespec now) |
Paul Mackerras | f2783c1 | 2005-10-20 09:23:26 +1000 | [diff] [blame] | 713 | { |
| 714 | struct rtc_time tm; |
| 715 | |
Tony Breeds | aa3be5f | 2007-09-21 13:26:02 +1000 | [diff] [blame] | 716 | if (!ppc_md.set_rtc_time) |
| 717 | return 0; |
| 718 | |
| 719 | to_tm(now.tv_sec + 1 + timezone_offset, &tm); |
| 720 | tm.tm_year -= 1900; |
| 721 | tm.tm_mon -= 1; |
| 722 | |
| 723 | return ppc_md.set_rtc_time(&tm); |
| 724 | } |
| 725 | |
| 726 | unsigned long read_persistent_clock(void) |
| 727 | { |
| 728 | struct rtc_time tm; |
| 729 | static int first = 1; |
| 730 | |
| 731 | /* XXX this is a litle fragile but will work okay in the short term */ |
| 732 | if (first) { |
| 733 | first = 0; |
| 734 | if (ppc_md.time_init) |
| 735 | timezone_offset = ppc_md.time_init(); |
| 736 | |
| 737 | /* get_boot_time() isn't guaranteed to be safe to call late */ |
| 738 | if (ppc_md.get_boot_time) |
| 739 | return ppc_md.get_boot_time() -timezone_offset; |
| 740 | } |
Paul Mackerras | f2783c1 | 2005-10-20 09:23:26 +1000 | [diff] [blame] | 741 | if (!ppc_md.get_rtc_time) |
| 742 | return 0; |
| 743 | ppc_md.get_rtc_time(&tm); |
| 744 | return mktime(tm.tm_year+1900, tm.tm_mon+1, tm.tm_mday, |
| 745 | tm.tm_hour, tm.tm_min, tm.tm_sec); |
| 746 | } |
| 747 | |
Tony Breeds | 4a4cfe3 | 2007-09-22 07:35:52 +1000 | [diff] [blame] | 748 | /* clocksource code */ |
| 749 | static cycle_t rtc_read(void) |
| 750 | { |
| 751 | return (cycle_t)get_rtc(); |
| 752 | } |
| 753 | |
| 754 | static cycle_t timebase_read(void) |
| 755 | { |
| 756 | return (cycle_t)get_tb(); |
| 757 | } |
| 758 | |
| 759 | void update_vsyscall(struct timespec *wall_time, struct clocksource *clock) |
| 760 | { |
| 761 | u64 t2x, stamp_xsec; |
| 762 | |
| 763 | if (clock != &clocksource_timebase) |
| 764 | return; |
| 765 | |
| 766 | /* Make userspace gettimeofday spin until we're done. */ |
| 767 | ++vdso_data->tb_update_count; |
| 768 | smp_mb(); |
| 769 | |
| 770 | /* XXX this assumes clock->shift == 22 */ |
| 771 | /* 4611686018 ~= 2^(20+64-22) / 1e9 */ |
| 772 | t2x = (u64) clock->mult * 4611686018ULL; |
| 773 | stamp_xsec = (u64) xtime.tv_nsec * XSEC_PER_SEC; |
| 774 | do_div(stamp_xsec, 1000000000); |
| 775 | stamp_xsec += (u64) xtime.tv_sec * XSEC_PER_SEC; |
| 776 | update_gtod(clock->cycle_last, stamp_xsec, t2x); |
| 777 | } |
| 778 | |
| 779 | void update_vsyscall_tz(void) |
| 780 | { |
| 781 | /* Make userspace gettimeofday spin until we're done. */ |
| 782 | ++vdso_data->tb_update_count; |
| 783 | smp_mb(); |
| 784 | vdso_data->tz_minuteswest = sys_tz.tz_minuteswest; |
| 785 | vdso_data->tz_dsttime = sys_tz.tz_dsttime; |
| 786 | smp_mb(); |
| 787 | ++vdso_data->tb_update_count; |
| 788 | } |
| 789 | |
| 790 | void __init clocksource_init(void) |
| 791 | { |
| 792 | struct clocksource *clock; |
| 793 | |
| 794 | if (__USE_RTC()) |
| 795 | clock = &clocksource_rtc; |
| 796 | else |
| 797 | clock = &clocksource_timebase; |
| 798 | |
| 799 | clock->mult = clocksource_hz2mult(tb_ticks_per_sec, clock->shift); |
| 800 | |
| 801 | if (clocksource_register(clock)) { |
| 802 | printk(KERN_ERR "clocksource: %s is already registered\n", |
| 803 | clock->name); |
| 804 | return; |
| 805 | } |
| 806 | |
| 807 | printk(KERN_INFO "clocksource: %s mult[%x] shift[%d] registered\n", |
| 808 | clock->name, clock->mult, clock->shift); |
| 809 | } |
| 810 | |
Tony Breeds | d831d0b | 2007-09-21 13:26:03 +1000 | [diff] [blame] | 811 | static int decrementer_set_next_event(unsigned long evt, |
| 812 | struct clock_event_device *dev) |
| 813 | { |
Paul Mackerras | d968014 | 2007-10-09 09:59:17 +1000 | [diff] [blame] | 814 | __get_cpu_var(decrementer_next_tb) = get_tb_or_rtc() + evt; |
Tony Breeds | d831d0b | 2007-09-21 13:26:03 +1000 | [diff] [blame] | 815 | set_dec(evt); |
| 816 | return 0; |
| 817 | } |
| 818 | |
| 819 | static void decrementer_set_mode(enum clock_event_mode mode, |
| 820 | struct clock_event_device *dev) |
| 821 | { |
| 822 | if (mode != CLOCK_EVT_MODE_ONESHOT) |
| 823 | decrementer_set_next_event(DECREMENTER_MAX, dev); |
| 824 | } |
| 825 | |
| 826 | static void register_decrementer_clockevent(int cpu) |
| 827 | { |
| 828 | struct clock_event_device *dec = &per_cpu(decrementers, cpu); |
| 829 | |
| 830 | *dec = decrementer_clockevent; |
| 831 | dec->cpumask = cpumask_of_cpu(cpu); |
| 832 | |
Tony Breeds | 0302f12 | 2007-11-12 14:25:50 +1100 | [diff] [blame] | 833 | printk(KERN_DEBUG "clockevent: %s mult[%lx] shift[%d] cpu[%d]\n", |
Tony Breeds | d831d0b | 2007-09-21 13:26:03 +1000 | [diff] [blame] | 834 | dec->name, dec->mult, dec->shift, cpu); |
| 835 | |
| 836 | clockevents_register_device(dec); |
| 837 | } |
| 838 | |
| 839 | void init_decrementer_clockevent(void) |
| 840 | { |
| 841 | int cpu = smp_processor_id(); |
| 842 | |
| 843 | decrementer_clockevent.mult = div_sc(ppc_tb_freq, NSEC_PER_SEC, |
| 844 | decrementer_clockevent.shift); |
| 845 | decrementer_clockevent.max_delta_ns = |
| 846 | clockevent_delta2ns(DECREMENTER_MAX, &decrementer_clockevent); |
Paul Mackerras | 43875cc | 2007-10-31 22:25:35 +1100 | [diff] [blame] | 847 | decrementer_clockevent.min_delta_ns = |
| 848 | clockevent_delta2ns(2, &decrementer_clockevent); |
Tony Breeds | d831d0b | 2007-09-21 13:26:03 +1000 | [diff] [blame] | 849 | |
| 850 | register_decrementer_clockevent(cpu); |
| 851 | } |
| 852 | |
| 853 | void secondary_cpu_time_init(void) |
| 854 | { |
| 855 | /* FIME: Should make unrelatred change to move snapshot_timebase |
| 856 | * call here ! */ |
| 857 | register_decrementer_clockevent(smp_processor_id()); |
| 858 | } |
| 859 | |
Paul Mackerras | f2783c1 | 2005-10-20 09:23:26 +1000 | [diff] [blame] | 860 | /* This function is only called on the boot processor */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 861 | void __init time_init(void) |
| 862 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 863 | unsigned long flags; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 864 | struct div_result res; |
Paul Mackerras | 092b8f3 | 2006-02-20 10:38:56 +1100 | [diff] [blame] | 865 | u64 scale, x; |
Paul Mackerras | f2783c1 | 2005-10-20 09:23:26 +1000 | [diff] [blame] | 866 | unsigned shift; |
| 867 | |
Paul Mackerras | 96c4450 | 2005-10-23 17:14:56 +1000 | [diff] [blame] | 868 | if (__USE_RTC()) { |
| 869 | /* 601 processor: dec counts down by 128 every 128ns */ |
| 870 | ppc_tb_freq = 1000000000; |
Paul Mackerras | eb36c28 | 2006-08-30 16:13:16 +1000 | [diff] [blame] | 871 | tb_last_jiffy = get_rtcl(); |
Paul Mackerras | 96c4450 | 2005-10-23 17:14:56 +1000 | [diff] [blame] | 872 | } else { |
| 873 | /* Normal PowerPC with timebase register */ |
| 874 | ppc_md.calibrate_decr(); |
Olof Johansson | 224ad80 | 2006-04-12 15:20:27 -0500 | [diff] [blame] | 875 | printk(KERN_DEBUG "time_init: decrementer frequency = %lu.%.6lu MHz\n", |
Paul Mackerras | 96c4450 | 2005-10-23 17:14:56 +1000 | [diff] [blame] | 876 | ppc_tb_freq / 1000000, ppc_tb_freq % 1000000); |
Olof Johansson | 224ad80 | 2006-04-12 15:20:27 -0500 | [diff] [blame] | 877 | printk(KERN_DEBUG "time_init: processor frequency = %lu.%.6lu MHz\n", |
Paul Mackerras | 96c4450 | 2005-10-23 17:14:56 +1000 | [diff] [blame] | 878 | ppc_proc_freq / 1000000, ppc_proc_freq % 1000000); |
Paul Mackerras | eb36c28 | 2006-08-30 16:13:16 +1000 | [diff] [blame] | 879 | tb_last_jiffy = get_tb(); |
Paul Mackerras | 96c4450 | 2005-10-23 17:14:56 +1000 | [diff] [blame] | 880 | } |
Paul Mackerras | 374e99d | 2005-10-20 21:04:51 +1000 | [diff] [blame] | 881 | |
| 882 | tb_ticks_per_jiffy = ppc_tb_freq / HZ; |
Paul Mackerras | 092b8f3 | 2006-02-20 10:38:56 +1100 | [diff] [blame] | 883 | tb_ticks_per_sec = ppc_tb_freq; |
Paul Mackerras | 374e99d | 2005-10-20 21:04:51 +1000 | [diff] [blame] | 884 | tb_ticks_per_usec = ppc_tb_freq / 1000000; |
| 885 | tb_to_us = mulhwu_scale_factor(ppc_tb_freq, 1000000); |
Paul Mackerras | c6622f6 | 2006-02-24 10:06:59 +1100 | [diff] [blame] | 886 | calc_cputime_factors(); |
Paul Mackerras | 092b8f3 | 2006-02-20 10:38:56 +1100 | [diff] [blame] | 887 | |
| 888 | /* |
| 889 | * Calculate the length of each tick in ns. It will not be |
| 890 | * exactly 1e9/HZ unless ppc_tb_freq is divisible by HZ. |
| 891 | * We compute 1e9 * tb_ticks_per_jiffy / ppc_tb_freq, |
| 892 | * rounded up. |
| 893 | */ |
| 894 | x = (u64) NSEC_PER_SEC * tb_ticks_per_jiffy + ppc_tb_freq - 1; |
| 895 | do_div(x, ppc_tb_freq); |
| 896 | tick_nsec = x; |
| 897 | last_tick_len = x << TICKLEN_SCALE; |
| 898 | |
| 899 | /* |
| 900 | * Compute ticklen_to_xs, which is a factor which gets multiplied |
| 901 | * by (last_tick_len << TICKLEN_SHIFT) to get a tb_to_xs value. |
| 902 | * It is computed as: |
| 903 | * ticklen_to_xs = 2^N / (tb_ticks_per_jiffy * 1e9) |
| 904 | * where N = 64 + 20 - TICKLEN_SCALE - TICKLEN_SHIFT |
Paul Mackerras | 0a45d44 | 2006-03-15 13:47:15 +1100 | [diff] [blame] | 905 | * which turns out to be N = 51 - SHIFT_HZ. |
| 906 | * This gives the result as a 0.64 fixed-point fraction. |
| 907 | * That value is reduced by an offset amounting to 1 xsec per |
| 908 | * 2^31 timebase ticks to avoid problems with time going backwards |
| 909 | * by 1 xsec when we do timer_recalc_offset due to losing the |
| 910 | * fractional xsec. That offset is equal to ppc_tb_freq/2^51 |
| 911 | * since there are 2^20 xsec in a second. |
Paul Mackerras | 092b8f3 | 2006-02-20 10:38:56 +1100 | [diff] [blame] | 912 | */ |
Paul Mackerras | 0a45d44 | 2006-03-15 13:47:15 +1100 | [diff] [blame] | 913 | div128_by_32((1ULL << 51) - ppc_tb_freq, 0, |
| 914 | tb_ticks_per_jiffy << SHIFT_HZ, &res); |
Paul Mackerras | 092b8f3 | 2006-02-20 10:38:56 +1100 | [diff] [blame] | 915 | div128_by_32(res.result_high, res.result_low, NSEC_PER_SEC, &res); |
| 916 | ticklen_to_xs = res.result_low; |
| 917 | |
| 918 | /* Compute tb_to_xs from tick_nsec */ |
| 919 | tb_to_xs = mulhdu(last_tick_len << TICKLEN_SHIFT, ticklen_to_xs); |
Paul Mackerras | 374e99d | 2005-10-20 21:04:51 +1000 | [diff] [blame] | 920 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 921 | /* |
| 922 | * Compute scale factor for sched_clock. |
| 923 | * The calibrate_decr() function has set tb_ticks_per_sec, |
| 924 | * which is the timebase frequency. |
| 925 | * We compute 1e9 * 2^64 / tb_ticks_per_sec and interpret |
| 926 | * the 128-bit result as a 64.64 fixed-point number. |
| 927 | * We then shift that number right until it is less than 1.0, |
| 928 | * giving us the scale factor and shift count to use in |
| 929 | * sched_clock(). |
| 930 | */ |
| 931 | div128_by_32(1000000000, 0, tb_ticks_per_sec, &res); |
| 932 | scale = res.result_low; |
| 933 | for (shift = 0; res.result_high != 0; ++shift) { |
| 934 | scale = (scale >> 1) | (res.result_high << 63); |
| 935 | res.result_high >>= 1; |
| 936 | } |
| 937 | tb_to_ns_scale = scale; |
| 938 | tb_to_ns_shift = shift; |
Tony Breeds | fc9069fe | 2007-07-04 14:04:31 +1000 | [diff] [blame] | 939 | /* Save the current timebase to pretty up CONFIG_PRINTK_TIME */ |
Benjamin Herrenschmidt | c27da339 | 2007-09-19 14:21:56 +1000 | [diff] [blame] | 940 | boot_tb = get_tb_or_rtc(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 941 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 942 | write_seqlock_irqsave(&xtime_lock, flags); |
Paul Mackerras | 092b8f3 | 2006-02-20 10:38:56 +1100 | [diff] [blame] | 943 | |
| 944 | /* If platform provided a timezone (pmac), we correct the time */ |
| 945 | if (timezone_offset) { |
| 946 | sys_tz.tz_minuteswest = -timezone_offset / 60; |
| 947 | sys_tz.tz_dsttime = 0; |
Paul Mackerras | 092b8f3 | 2006-02-20 10:38:56 +1100 | [diff] [blame] | 948 | } |
| 949 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 950 | do_gtod.varp = &do_gtod.vars[0]; |
| 951 | do_gtod.var_idx = 0; |
Paul Mackerras | 96c4450 | 2005-10-23 17:14:56 +1000 | [diff] [blame] | 952 | do_gtod.varp->tb_orig_stamp = tb_last_jiffy; |
Paul Mackerras | eb36c28 | 2006-08-30 16:13:16 +1000 | [diff] [blame] | 953 | __get_cpu_var(last_jiffy) = tb_last_jiffy; |
Paul Mackerras | f2783c1 | 2005-10-20 09:23:26 +1000 | [diff] [blame] | 954 | do_gtod.varp->stamp_xsec = (u64) xtime.tv_sec * XSEC_PER_SEC; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 955 | do_gtod.tb_ticks_per_sec = tb_ticks_per_sec; |
| 956 | do_gtod.varp->tb_to_xs = tb_to_xs; |
| 957 | do_gtod.tb_to_us = tb_to_us; |
Benjamin Herrenschmidt | a7f290d | 2005-11-11 21:15:21 +1100 | [diff] [blame] | 958 | |
| 959 | vdso_data->tb_orig_stamp = tb_last_jiffy; |
| 960 | vdso_data->tb_update_count = 0; |
| 961 | vdso_data->tb_ticks_per_sec = tb_ticks_per_sec; |
Paul Mackerras | 092b8f3 | 2006-02-20 10:38:56 +1100 | [diff] [blame] | 962 | vdso_data->stamp_xsec = (u64) xtime.tv_sec * XSEC_PER_SEC; |
Benjamin Herrenschmidt | a7f290d | 2005-11-11 21:15:21 +1100 | [diff] [blame] | 963 | vdso_data->tb_to_xs = tb_to_xs; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 964 | |
| 965 | time_freq = 0; |
| 966 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 967 | write_sequnlock_irqrestore(&xtime_lock, flags); |
| 968 | |
Tony Breeds | 4a4cfe3 | 2007-09-22 07:35:52 +1000 | [diff] [blame] | 969 | /* Register the clocksource, if we're not running on iSeries */ |
| 970 | if (!firmware_has_feature(FW_FEATURE_ISERIES)) |
| 971 | clocksource_init(); |
| 972 | |
Tony Breeds | d831d0b | 2007-09-21 13:26:03 +1000 | [diff] [blame] | 973 | init_decrementer_clockevent(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 974 | } |
| 975 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 976 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 977 | #define FEBRUARY 2 |
| 978 | #define STARTOFTIME 1970 |
| 979 | #define SECDAY 86400L |
| 980 | #define SECYR (SECDAY * 365) |
Paul Mackerras | f2783c1 | 2005-10-20 09:23:26 +1000 | [diff] [blame] | 981 | #define leapyear(year) ((year) % 4 == 0 && \ |
| 982 | ((year) % 100 != 0 || (year) % 400 == 0)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 983 | #define days_in_year(a) (leapyear(a) ? 366 : 365) |
| 984 | #define days_in_month(a) (month_days[(a) - 1]) |
| 985 | |
| 986 | static int month_days[12] = { |
| 987 | 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 |
| 988 | }; |
| 989 | |
| 990 | /* |
| 991 | * This only works for the Gregorian calendar - i.e. after 1752 (in the UK) |
| 992 | */ |
| 993 | void GregorianDay(struct rtc_time * tm) |
| 994 | { |
| 995 | int leapsToDate; |
| 996 | int lastYear; |
| 997 | int day; |
| 998 | int MonthOffset[] = { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 }; |
| 999 | |
Paul Mackerras | f2783c1 | 2005-10-20 09:23:26 +1000 | [diff] [blame] | 1000 | lastYear = tm->tm_year - 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1001 | |
| 1002 | /* |
| 1003 | * Number of leap corrections to apply up to end of last year |
| 1004 | */ |
Paul Mackerras | f2783c1 | 2005-10-20 09:23:26 +1000 | [diff] [blame] | 1005 | leapsToDate = lastYear / 4 - lastYear / 100 + lastYear / 400; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1006 | |
| 1007 | /* |
| 1008 | * This year is a leap year if it is divisible by 4 except when it is |
| 1009 | * divisible by 100 unless it is divisible by 400 |
| 1010 | * |
Paul Mackerras | f2783c1 | 2005-10-20 09:23:26 +1000 | [diff] [blame] | 1011 | * e.g. 1904 was a leap year, 1900 was not, 1996 is, and 2000 was |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1012 | */ |
Paul Mackerras | f2783c1 | 2005-10-20 09:23:26 +1000 | [diff] [blame] | 1013 | day = tm->tm_mon > 2 && leapyear(tm->tm_year); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1014 | |
| 1015 | day += lastYear*365 + leapsToDate + MonthOffset[tm->tm_mon-1] + |
| 1016 | tm->tm_mday; |
| 1017 | |
Paul Mackerras | f2783c1 | 2005-10-20 09:23:26 +1000 | [diff] [blame] | 1018 | tm->tm_wday = day % 7; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1019 | } |
| 1020 | |
| 1021 | void to_tm(int tim, struct rtc_time * tm) |
| 1022 | { |
| 1023 | register int i; |
| 1024 | register long hms, day; |
| 1025 | |
| 1026 | day = tim / SECDAY; |
| 1027 | hms = tim % SECDAY; |
| 1028 | |
| 1029 | /* Hours, minutes, seconds are easy */ |
| 1030 | tm->tm_hour = hms / 3600; |
| 1031 | tm->tm_min = (hms % 3600) / 60; |
| 1032 | tm->tm_sec = (hms % 3600) % 60; |
| 1033 | |
| 1034 | /* Number of years in days */ |
| 1035 | for (i = STARTOFTIME; day >= days_in_year(i); i++) |
| 1036 | day -= days_in_year(i); |
| 1037 | tm->tm_year = i; |
| 1038 | |
| 1039 | /* Number of months in days left */ |
| 1040 | if (leapyear(tm->tm_year)) |
| 1041 | days_in_month(FEBRUARY) = 29; |
| 1042 | for (i = 1; day >= days_in_month(i); i++) |
| 1043 | day -= days_in_month(i); |
| 1044 | days_in_month(FEBRUARY) = 28; |
| 1045 | tm->tm_mon = i; |
| 1046 | |
| 1047 | /* Days are what is left over (+1) from all that. */ |
| 1048 | tm->tm_mday = day + 1; |
| 1049 | |
| 1050 | /* |
| 1051 | * Determine the day of week |
| 1052 | */ |
| 1053 | GregorianDay(tm); |
| 1054 | } |
| 1055 | |
| 1056 | /* Auxiliary function to compute scaling factors */ |
| 1057 | /* Actually the choice of a timebase running at 1/4 the of the bus |
| 1058 | * frequency giving resolution of a few tens of nanoseconds is quite nice. |
| 1059 | * It makes this computation very precise (27-28 bits typically) which |
| 1060 | * is optimistic considering the stability of most processor clock |
| 1061 | * oscillators and the precision with which the timebase frequency |
| 1062 | * is measured but does not harm. |
| 1063 | */ |
Paul Mackerras | f2783c1 | 2005-10-20 09:23:26 +1000 | [diff] [blame] | 1064 | unsigned mulhwu_scale_factor(unsigned inscale, unsigned outscale) |
| 1065 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1066 | unsigned mlt=0, tmp, err; |
| 1067 | /* No concern for performance, it's done once: use a stupid |
| 1068 | * but safe and compact method to find the multiplier. |
| 1069 | */ |
| 1070 | |
| 1071 | for (tmp = 1U<<31; tmp != 0; tmp >>= 1) { |
Paul Mackerras | f2783c1 | 2005-10-20 09:23:26 +1000 | [diff] [blame] | 1072 | if (mulhwu(inscale, mlt|tmp) < outscale) |
| 1073 | mlt |= tmp; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1074 | } |
| 1075 | |
| 1076 | /* We might still be off by 1 for the best approximation. |
| 1077 | * A side effect of this is that if outscale is too large |
| 1078 | * the returned value will be zero. |
| 1079 | * Many corner cases have been checked and seem to work, |
| 1080 | * some might have been forgotten in the test however. |
| 1081 | */ |
| 1082 | |
Paul Mackerras | f2783c1 | 2005-10-20 09:23:26 +1000 | [diff] [blame] | 1083 | err = inscale * (mlt+1); |
| 1084 | if (err <= inscale/2) |
| 1085 | mlt++; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1086 | return mlt; |
Paul Mackerras | f2783c1 | 2005-10-20 09:23:26 +1000 | [diff] [blame] | 1087 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1088 | |
| 1089 | /* |
| 1090 | * Divide a 128-bit dividend by a 32-bit divisor, leaving a 128 bit |
| 1091 | * result. |
| 1092 | */ |
Paul Mackerras | f2783c1 | 2005-10-20 09:23:26 +1000 | [diff] [blame] | 1093 | void div128_by_32(u64 dividend_high, u64 dividend_low, |
| 1094 | unsigned divisor, struct div_result *dr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1095 | { |
Paul Mackerras | f2783c1 | 2005-10-20 09:23:26 +1000 | [diff] [blame] | 1096 | unsigned long a, b, c, d; |
| 1097 | unsigned long w, x, y, z; |
| 1098 | u64 ra, rb, rc; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1099 | |
| 1100 | a = dividend_high >> 32; |
| 1101 | b = dividend_high & 0xffffffff; |
| 1102 | c = dividend_low >> 32; |
| 1103 | d = dividend_low & 0xffffffff; |
| 1104 | |
Paul Mackerras | f2783c1 | 2005-10-20 09:23:26 +1000 | [diff] [blame] | 1105 | w = a / divisor; |
| 1106 | ra = ((u64)(a - (w * divisor)) << 32) + b; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1107 | |
Paul Mackerras | f2783c1 | 2005-10-20 09:23:26 +1000 | [diff] [blame] | 1108 | rb = ((u64) do_div(ra, divisor) << 32) + c; |
| 1109 | x = ra; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1110 | |
Paul Mackerras | f2783c1 | 2005-10-20 09:23:26 +1000 | [diff] [blame] | 1111 | rc = ((u64) do_div(rb, divisor) << 32) + d; |
| 1112 | y = rb; |
| 1113 | |
| 1114 | do_div(rc, divisor); |
| 1115 | z = rc; |
Paul Mackerras | f2783c1 | 2005-10-20 09:23:26 +1000 | [diff] [blame] | 1116 | |
| 1117 | dr->result_high = ((u64)w << 32) + x; |
| 1118 | dr->result_low = ((u64)y << 32) + z; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1119 | |
| 1120 | } |