Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
1da177e4 LT |
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 | ||
1da177e4 LT |
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> | |
1da177e4 LT |
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> | |
f2783c15 PM |
50 | #include <linux/percpu.h> |
51 | #include <linux/rtc.h> | |
092b8f34 | 52 | #include <linux/jiffies.h> |
c6622f63 | 53 | #include <linux/posix-timers.h> |
7d12e780 | 54 | #include <linux/irq.h> |
1da177e4 | 55 | |
1da177e4 LT |
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> | |
1da177e4 LT |
61 | #include <asm/uaccess.h> |
62 | #include <asm/time.h> | |
1da177e4 | 63 | #include <asm/prom.h> |
f2783c15 PM |
64 | #include <asm/irq.h> |
65 | #include <asm/div64.h> | |
2249ca9d | 66 | #include <asm/smp.h> |
a7f290da | 67 | #include <asm/vdso_datapage.h> |
1ababe11 | 68 | #include <asm/firmware.h> |
f2783c15 | 69 | #ifdef CONFIG_PPC_ISERIES |
8875ccfb | 70 | #include <asm/iseries/it_lp_queue.h> |
8021b8a7 | 71 | #include <asm/iseries/hv_call_xm.h> |
f2783c15 | 72 | #endif |
1da177e4 | 73 | |
4a4cfe38 TB |
74 | /* powerpc clocksource/clockevent code */ |
75 | ||
d831d0b8 | 76 | #include <linux/clockchips.h> |
4a4cfe38 TB |
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 | ||
d831d0b8 TB |
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, | |
cdec12ae | 111 | .shift = 16, |
d831d0b8 TB |
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 | ||
6e6b44e8 MM |
119 | struct decrementer_clock { |
120 | struct clock_event_device event; | |
121 | u64 next_tb; | |
122 | }; | |
123 | ||
124 | static DEFINE_PER_CPU(struct decrementer_clock, decrementers); | |
d831d0b8 | 125 | |
1da177e4 | 126 | #ifdef CONFIG_PPC_ISERIES |
71712b45 TB |
127 | static unsigned long __initdata iSeries_recal_titan; |
128 | static signed long __initdata iSeries_recal_tb; | |
4a4cfe38 TB |
129 | |
130 | /* Forward declaration is only needed for iSereis compiles */ | |
131 | void __init clocksource_init(void); | |
1da177e4 LT |
132 | #endif |
133 | ||
134 | #define XSEC_PER_SEC (1024*1024) | |
135 | ||
f2783c15 PM |
136 | #ifdef CONFIG_PPC64 |
137 | #define SCALE_XSEC(xsec, max) (((xsec) * max) / XSEC_PER_SEC) | |
138 | #else | |
139 | /* compute ((xsec << 12) * max) >> 32 */ | |
140 | #define SCALE_XSEC(xsec, max) mulhwu((xsec) << 12, max) | |
141 | #endif | |
142 | ||
1da177e4 LT |
143 | unsigned long tb_ticks_per_jiffy; |
144 | unsigned long tb_ticks_per_usec = 100; /* sane default */ | |
145 | EXPORT_SYMBOL(tb_ticks_per_usec); | |
146 | unsigned long tb_ticks_per_sec; | |
2cf82c02 | 147 | EXPORT_SYMBOL(tb_ticks_per_sec); /* for cputime_t conversions */ |
f2783c15 PM |
148 | u64 tb_to_xs; |
149 | unsigned tb_to_us; | |
092b8f34 | 150 | |
19923c19 | 151 | #define TICKLEN_SCALE TICK_LENGTH_SHIFT |
092b8f34 PM |
152 | u64 last_tick_len; /* units are ns / 2^TICKLEN_SCALE */ |
153 | u64 ticklen_to_xs; /* 0.64 fraction */ | |
154 | ||
155 | /* If last_tick_len corresponds to about 1/HZ seconds, then | |
156 | last_tick_len << TICKLEN_SHIFT will be about 2^63. */ | |
157 | #define TICKLEN_SHIFT (63 - 30 - TICKLEN_SCALE + SHIFT_HZ) | |
158 | ||
1da177e4 | 159 | DEFINE_SPINLOCK(rtc_lock); |
6ae3db11 | 160 | EXPORT_SYMBOL_GPL(rtc_lock); |
1da177e4 | 161 | |
fc9069fe TB |
162 | static u64 tb_to_ns_scale __read_mostly; |
163 | static unsigned tb_to_ns_shift __read_mostly; | |
164 | static unsigned long boot_tb __read_mostly; | |
1da177e4 LT |
165 | |
166 | struct gettimeofday_struct do_gtod; | |
167 | ||
1da177e4 | 168 | extern struct timezone sys_tz; |
f2783c15 | 169 | static long timezone_offset; |
1da177e4 | 170 | |
10f7e7c1 | 171 | unsigned long ppc_proc_freq; |
1474855d | 172 | EXPORT_SYMBOL(ppc_proc_freq); |
10f7e7c1 AB |
173 | unsigned long ppc_tb_freq; |
174 | ||
eb36c288 PM |
175 | static u64 tb_last_jiffy __cacheline_aligned_in_smp; |
176 | static DEFINE_PER_CPU(u64, last_jiffy); | |
96c44507 | 177 | |
c6622f63 PM |
178 | #ifdef CONFIG_VIRT_CPU_ACCOUNTING |
179 | /* | |
180 | * Factors for converting from cputime_t (timebase ticks) to | |
181 | * jiffies, milliseconds, seconds, and clock_t (1/USER_HZ seconds). | |
182 | * These are all stored as 0.64 fixed-point binary fractions. | |
183 | */ | |
184 | u64 __cputime_jiffies_factor; | |
2cf82c02 | 185 | EXPORT_SYMBOL(__cputime_jiffies_factor); |
c6622f63 | 186 | u64 __cputime_msec_factor; |
2cf82c02 | 187 | EXPORT_SYMBOL(__cputime_msec_factor); |
c6622f63 | 188 | u64 __cputime_sec_factor; |
2cf82c02 | 189 | EXPORT_SYMBOL(__cputime_sec_factor); |
c6622f63 | 190 | u64 __cputime_clockt_factor; |
2cf82c02 | 191 | EXPORT_SYMBOL(__cputime_clockt_factor); |
c6622f63 PM |
192 | |
193 | static void calc_cputime_factors(void) | |
194 | { | |
195 | struct div_result res; | |
196 | ||
197 | div128_by_32(HZ, 0, tb_ticks_per_sec, &res); | |
198 | __cputime_jiffies_factor = res.result_low; | |
199 | div128_by_32(1000, 0, tb_ticks_per_sec, &res); | |
200 | __cputime_msec_factor = res.result_low; | |
201 | div128_by_32(1, 0, tb_ticks_per_sec, &res); | |
202 | __cputime_sec_factor = res.result_low; | |
203 | div128_by_32(USER_HZ, 0, tb_ticks_per_sec, &res); | |
204 | __cputime_clockt_factor = res.result_low; | |
205 | } | |
206 | ||
207 | /* | |
208 | * Read the PURR on systems that have it, otherwise the timebase. | |
209 | */ | |
210 | static u64 read_purr(void) | |
211 | { | |
212 | if (cpu_has_feature(CPU_FTR_PURR)) | |
213 | return mfspr(SPRN_PURR); | |
214 | return mftb(); | |
215 | } | |
216 | ||
4603ac18 MN |
217 | /* |
218 | * Read the SPURR on systems that have it, otherwise the purr | |
219 | */ | |
220 | static u64 read_spurr(u64 purr) | |
221 | { | |
222 | if (cpu_has_feature(CPU_FTR_SPURR)) | |
223 | return mfspr(SPRN_SPURR); | |
224 | return purr; | |
225 | } | |
226 | ||
c6622f63 PM |
227 | /* |
228 | * Account time for a transition between system, hard irq | |
229 | * or soft irq state. | |
230 | */ | |
231 | void account_system_vtime(struct task_struct *tsk) | |
232 | { | |
4603ac18 | 233 | u64 now, nowscaled, delta, deltascaled; |
c6622f63 PM |
234 | unsigned long flags; |
235 | ||
236 | local_irq_save(flags); | |
237 | now = read_purr(); | |
238 | delta = now - get_paca()->startpurr; | |
239 | get_paca()->startpurr = now; | |
4603ac18 MN |
240 | nowscaled = read_spurr(now); |
241 | deltascaled = nowscaled - get_paca()->startspurr; | |
242 | get_paca()->startspurr = nowscaled; | |
c6622f63 | 243 | if (!in_interrupt()) { |
4603ac18 MN |
244 | /* deltascaled includes both user and system time. |
245 | * Hence scale it based on the purr ratio to estimate | |
246 | * the system time */ | |
2b46b567 MN |
247 | if (get_paca()->user_time) |
248 | deltascaled = deltascaled * get_paca()->system_time / | |
249 | (get_paca()->system_time + get_paca()->user_time); | |
c6622f63 PM |
250 | delta += get_paca()->system_time; |
251 | get_paca()->system_time = 0; | |
252 | } | |
253 | account_system_time(tsk, 0, delta); | |
4603ac18 MN |
254 | get_paca()->purrdelta = delta; |
255 | account_system_time_scaled(tsk, deltascaled); | |
256 | get_paca()->spurrdelta = deltascaled; | |
c6622f63 PM |
257 | local_irq_restore(flags); |
258 | } | |
259 | ||
260 | /* | |
261 | * Transfer the user and system times accumulated in the paca | |
262 | * by the exception entry and exit code to the generic process | |
263 | * user and system time records. | |
264 | * Must be called with interrupts disabled. | |
265 | */ | |
fa13a5a1 | 266 | void account_process_tick(struct task_struct *tsk, int user_tick) |
c6622f63 | 267 | { |
4603ac18 | 268 | cputime_t utime, utimescaled; |
c6622f63 PM |
269 | |
270 | utime = get_paca()->user_time; | |
271 | get_paca()->user_time = 0; | |
272 | account_user_time(tsk, utime); | |
4603ac18 MN |
273 | |
274 | /* Estimate the scaled utime by scaling the real utime based | |
275 | * on the last spurr to purr ratio */ | |
276 | utimescaled = utime * get_paca()->spurrdelta / get_paca()->purrdelta; | |
277 | get_paca()->spurrdelta = get_paca()->purrdelta = 0; | |
278 | account_user_time_scaled(tsk, utimescaled); | |
c6622f63 PM |
279 | } |
280 | ||
c6622f63 PM |
281 | /* |
282 | * Stuff for accounting stolen time. | |
283 | */ | |
284 | struct cpu_purr_data { | |
285 | int initialized; /* thread is running */ | |
c6622f63 PM |
286 | u64 tb; /* last TB value read */ |
287 | u64 purr; /* last PURR value read */ | |
4603ac18 | 288 | u64 spurr; /* last SPURR value read */ |
c6622f63 PM |
289 | }; |
290 | ||
df211c8a NL |
291 | /* |
292 | * Each entry in the cpu_purr_data array is manipulated only by its | |
293 | * "owner" cpu -- usually in the timer interrupt but also occasionally | |
294 | * in process context for cpu online. As long as cpus do not touch | |
295 | * each others' cpu_purr_data, disabling local interrupts is | |
296 | * sufficient to serialize accesses. | |
297 | */ | |
c6622f63 PM |
298 | static DEFINE_PER_CPU(struct cpu_purr_data, cpu_purr_data); |
299 | ||
300 | static void snapshot_tb_and_purr(void *data) | |
301 | { | |
df211c8a | 302 | unsigned long flags; |
c6622f63 PM |
303 | struct cpu_purr_data *p = &__get_cpu_var(cpu_purr_data); |
304 | ||
df211c8a | 305 | local_irq_save(flags); |
c27da339 | 306 | p->tb = get_tb_or_rtc(); |
cbcdb93d | 307 | p->purr = mfspr(SPRN_PURR); |
c6622f63 PM |
308 | wmb(); |
309 | p->initialized = 1; | |
df211c8a | 310 | local_irq_restore(flags); |
c6622f63 PM |
311 | } |
312 | ||
313 | /* | |
314 | * Called during boot when all cpus have come up. | |
315 | */ | |
316 | void snapshot_timebases(void) | |
317 | { | |
c6622f63 PM |
318 | if (!cpu_has_feature(CPU_FTR_PURR)) |
319 | return; | |
c6622f63 PM |
320 | on_each_cpu(snapshot_tb_and_purr, NULL, 0, 1); |
321 | } | |
322 | ||
df211c8a NL |
323 | /* |
324 | * Must be called with interrupts disabled. | |
325 | */ | |
c6622f63 PM |
326 | void calculate_steal_time(void) |
327 | { | |
cbcdb93d | 328 | u64 tb, purr; |
c6622f63 | 329 | s64 stolen; |
cbcdb93d | 330 | struct cpu_purr_data *pme; |
c6622f63 | 331 | |
8b5621f1 | 332 | pme = &__get_cpu_var(cpu_purr_data); |
c6622f63 | 333 | if (!pme->initialized) |
db3801a8 | 334 | return; /* !CPU_FTR_PURR or early in early boot */ |
c6622f63 | 335 | tb = mftb(); |
cbcdb93d SR |
336 | purr = mfspr(SPRN_PURR); |
337 | stolen = (tb - pme->tb) - (purr - pme->purr); | |
338 | if (stolen > 0) | |
c6622f63 | 339 | account_steal_time(current, stolen); |
c6622f63 PM |
340 | pme->tb = tb; |
341 | pme->purr = purr; | |
c6622f63 PM |
342 | } |
343 | ||
4cefebb1 | 344 | #ifdef CONFIG_PPC_SPLPAR |
c6622f63 PM |
345 | /* |
346 | * Must be called before the cpu is added to the online map when | |
347 | * a cpu is being brought up at runtime. | |
348 | */ | |
349 | static void snapshot_purr(void) | |
350 | { | |
cbcdb93d | 351 | struct cpu_purr_data *pme; |
c6622f63 PM |
352 | unsigned long flags; |
353 | ||
354 | if (!cpu_has_feature(CPU_FTR_PURR)) | |
355 | return; | |
df211c8a | 356 | local_irq_save(flags); |
8b5621f1 | 357 | pme = &__get_cpu_var(cpu_purr_data); |
cbcdb93d SR |
358 | pme->tb = mftb(); |
359 | pme->purr = mfspr(SPRN_PURR); | |
c6622f63 | 360 | pme->initialized = 1; |
df211c8a | 361 | local_irq_restore(flags); |
c6622f63 PM |
362 | } |
363 | ||
364 | #endif /* CONFIG_PPC_SPLPAR */ | |
365 | ||
366 | #else /* ! CONFIG_VIRT_CPU_ACCOUNTING */ | |
367 | #define calc_cputime_factors() | |
c6622f63 PM |
368 | #define calculate_steal_time() do { } while (0) |
369 | #endif | |
370 | ||
371 | #if !(defined(CONFIG_VIRT_CPU_ACCOUNTING) && defined(CONFIG_PPC_SPLPAR)) | |
372 | #define snapshot_purr() do { } while (0) | |
373 | #endif | |
374 | ||
375 | /* | |
376 | * Called when a cpu comes up after the system has finished booting, | |
377 | * i.e. as a result of a hotplug cpu action. | |
378 | */ | |
379 | void snapshot_timebase(void) | |
380 | { | |
c27da339 | 381 | __get_cpu_var(last_jiffy) = get_tb_or_rtc(); |
c6622f63 PM |
382 | snapshot_purr(); |
383 | } | |
384 | ||
6defa38b PM |
385 | void __delay(unsigned long loops) |
386 | { | |
387 | unsigned long start; | |
388 | int diff; | |
389 | ||
390 | if (__USE_RTC()) { | |
391 | start = get_rtcl(); | |
392 | do { | |
393 | /* the RTCL register wraps at 1000000000 */ | |
394 | diff = get_rtcl() - start; | |
395 | if (diff < 0) | |
396 | diff += 1000000000; | |
397 | } while (diff < loops); | |
398 | } else { | |
399 | start = get_tbl(); | |
400 | while (get_tbl() - start < loops) | |
401 | HMT_low(); | |
402 | HMT_medium(); | |
403 | } | |
404 | } | |
405 | EXPORT_SYMBOL(__delay); | |
406 | ||
407 | void udelay(unsigned long usecs) | |
408 | { | |
409 | __delay(tb_ticks_per_usec * usecs); | |
410 | } | |
411 | EXPORT_SYMBOL(udelay); | |
412 | ||
1da177e4 | 413 | |
1da177e4 | 414 | /* |
f2783c15 PM |
415 | * There are two copies of tb_to_xs and stamp_xsec so that no |
416 | * lock is needed to access and use these values in | |
417 | * do_gettimeofday. We alternate the copies and as long as a | |
418 | * reasonable time elapses between changes, there will never | |
419 | * be inconsistent values. ntpd has a minimum of one minute | |
420 | * between updates. | |
1da177e4 | 421 | */ |
f2783c15 | 422 | static inline void update_gtod(u64 new_tb_stamp, u64 new_stamp_xsec, |
5d14a18d | 423 | u64 new_tb_to_xs) |
1da177e4 | 424 | { |
1da177e4 | 425 | unsigned temp_idx; |
f2783c15 | 426 | struct gettimeofday_vars *temp_varp; |
1da177e4 LT |
427 | |
428 | temp_idx = (do_gtod.var_idx == 0); | |
429 | temp_varp = &do_gtod.vars[temp_idx]; | |
430 | ||
f2783c15 PM |
431 | temp_varp->tb_to_xs = new_tb_to_xs; |
432 | temp_varp->tb_orig_stamp = new_tb_stamp; | |
1da177e4 | 433 | temp_varp->stamp_xsec = new_stamp_xsec; |
0d8d4d42 | 434 | smp_mb(); |
1da177e4 LT |
435 | do_gtod.varp = temp_varp; |
436 | do_gtod.var_idx = temp_idx; | |
437 | ||
f2783c15 PM |
438 | /* |
439 | * tb_update_count is used to allow the userspace gettimeofday code | |
440 | * to assure itself that it sees a consistent view of the tb_to_xs and | |
441 | * stamp_xsec variables. It reads the tb_update_count, then reads | |
442 | * tb_to_xs and stamp_xsec and then reads tb_update_count again. If | |
443 | * the two values of tb_update_count match and are even then the | |
444 | * tb_to_xs and stamp_xsec values are consistent. If not, then it | |
445 | * loops back and reads them again until this criteria is met. | |
0a45d449 PM |
446 | * We expect the caller to have done the first increment of |
447 | * vdso_data->tb_update_count already. | |
f2783c15 | 448 | */ |
a7f290da BH |
449 | vdso_data->tb_orig_stamp = new_tb_stamp; |
450 | vdso_data->stamp_xsec = new_stamp_xsec; | |
451 | vdso_data->tb_to_xs = new_tb_to_xs; | |
452 | vdso_data->wtom_clock_sec = wall_to_monotonic.tv_sec; | |
453 | vdso_data->wtom_clock_nsec = wall_to_monotonic.tv_nsec; | |
0d8d4d42 | 454 | smp_wmb(); |
a7f290da | 455 | ++(vdso_data->tb_update_count); |
f2783c15 PM |
456 | } |
457 | ||
1da177e4 LT |
458 | #ifdef CONFIG_SMP |
459 | unsigned long profile_pc(struct pt_regs *regs) | |
460 | { | |
461 | unsigned long pc = instruction_pointer(regs); | |
462 | ||
463 | if (in_lock_functions(pc)) | |
464 | return regs->link; | |
465 | ||
466 | return pc; | |
467 | } | |
468 | EXPORT_SYMBOL(profile_pc); | |
469 | #endif | |
470 | ||
471 | #ifdef CONFIG_PPC_ISERIES | |
472 | ||
473 | /* | |
474 | * This function recalibrates the timebase based on the 49-bit time-of-day | |
475 | * value in the Titan chip. The Titan is much more accurate than the value | |
476 | * returned by the service processor for the timebase frequency. | |
477 | */ | |
478 | ||
71712b45 | 479 | static int __init iSeries_tb_recal(void) |
1da177e4 LT |
480 | { |
481 | struct div_result divres; | |
482 | unsigned long titan, tb; | |
71712b45 TB |
483 | |
484 | /* Make sure we only run on iSeries */ | |
485 | if (!firmware_has_feature(FW_FEATURE_ISERIES)) | |
486 | return -ENODEV; | |
487 | ||
1da177e4 LT |
488 | tb = get_tb(); |
489 | titan = HvCallXm_loadTod(); | |
490 | if ( iSeries_recal_titan ) { | |
491 | unsigned long tb_ticks = tb - iSeries_recal_tb; | |
492 | unsigned long titan_usec = (titan - iSeries_recal_titan) >> 12; | |
493 | unsigned long new_tb_ticks_per_sec = (tb_ticks * USEC_PER_SEC)/titan_usec; | |
494 | unsigned long new_tb_ticks_per_jiffy = (new_tb_ticks_per_sec+(HZ/2))/HZ; | |
495 | long tick_diff = new_tb_ticks_per_jiffy - tb_ticks_per_jiffy; | |
496 | char sign = '+'; | |
497 | /* make sure tb_ticks_per_sec and tb_ticks_per_jiffy are consistent */ | |
498 | new_tb_ticks_per_sec = new_tb_ticks_per_jiffy * HZ; | |
499 | ||
500 | if ( tick_diff < 0 ) { | |
501 | tick_diff = -tick_diff; | |
502 | sign = '-'; | |
503 | } | |
504 | if ( tick_diff ) { | |
505 | if ( tick_diff < tb_ticks_per_jiffy/25 ) { | |
506 | printk( "Titan recalibrate: new tb_ticks_per_jiffy = %lu (%c%ld)\n", | |
507 | new_tb_ticks_per_jiffy, sign, tick_diff ); | |
508 | tb_ticks_per_jiffy = new_tb_ticks_per_jiffy; | |
509 | tb_ticks_per_sec = new_tb_ticks_per_sec; | |
c6622f63 | 510 | calc_cputime_factors(); |
1da177e4 LT |
511 | div128_by_32( XSEC_PER_SEC, 0, tb_ticks_per_sec, &divres ); |
512 | do_gtod.tb_ticks_per_sec = tb_ticks_per_sec; | |
513 | tb_to_xs = divres.result_low; | |
514 | do_gtod.varp->tb_to_xs = tb_to_xs; | |
a7f290da BH |
515 | vdso_data->tb_ticks_per_sec = tb_ticks_per_sec; |
516 | vdso_data->tb_to_xs = tb_to_xs; | |
1da177e4 LT |
517 | } |
518 | else { | |
519 | printk( "Titan recalibrate: FAILED (difference > 4 percent)\n" | |
520 | " new tb_ticks_per_jiffy = %lu\n" | |
521 | " old tb_ticks_per_jiffy = %lu\n", | |
522 | new_tb_ticks_per_jiffy, tb_ticks_per_jiffy ); | |
523 | } | |
524 | } | |
525 | } | |
526 | iSeries_recal_titan = titan; | |
527 | iSeries_recal_tb = tb; | |
71712b45 | 528 | |
4a4cfe38 TB |
529 | /* Called here as now we know accurate values for the timebase */ |
530 | clocksource_init(); | |
71712b45 | 531 | return 0; |
1da177e4 | 532 | } |
71712b45 TB |
533 | late_initcall(iSeries_tb_recal); |
534 | ||
535 | /* Called from platform early init */ | |
536 | void __init iSeries_time_init_early(void) | |
537 | { | |
538 | iSeries_recal_tb = get_tb(); | |
539 | iSeries_recal_titan = HvCallXm_loadTod(); | |
540 | } | |
541 | #endif /* CONFIG_PPC_ISERIES */ | |
1da177e4 LT |
542 | |
543 | /* | |
544 | * For iSeries shared processors, we have to let the hypervisor | |
545 | * set the hardware decrementer. We set a virtual decrementer | |
546 | * in the lppaca and call the hypervisor if the virtual | |
547 | * decrementer is less than the current value in the hardware | |
548 | * decrementer. (almost always the new decrementer value will | |
549 | * be greater than the current hardware decementer so the hypervisor | |
550 | * call will not be needed) | |
551 | */ | |
552 | ||
1da177e4 LT |
553 | /* |
554 | * timer_interrupt - gets called when the decrementer overflows, | |
555 | * with interrupts disabled. | |
556 | */ | |
c7aeffc4 | 557 | void timer_interrupt(struct pt_regs * regs) |
1da177e4 | 558 | { |
7d12e780 | 559 | struct pt_regs *old_regs; |
6e6b44e8 MM |
560 | struct decrementer_clock *decrementer = &__get_cpu_var(decrementers); |
561 | struct clock_event_device *evt = &decrementer->event; | |
d968014b | 562 | u64 now; |
d831d0b8 TB |
563 | |
564 | /* Ensure a positive value is written to the decrementer, or else | |
565 | * some CPUs will continuue to take decrementer exceptions */ | |
566 | set_dec(DECREMENTER_MAX); | |
f2783c15 PM |
567 | |
568 | #ifdef CONFIG_PPC32 | |
569 | if (atomic_read(&ppc_n_lost_interrupts) != 0) | |
570 | do_IRQ(regs); | |
571 | #endif | |
1da177e4 | 572 | |
d968014b | 573 | now = get_tb_or_rtc(); |
6e6b44e8 | 574 | if (now < decrementer->next_tb) { |
d968014b | 575 | /* not time for this event yet */ |
6e6b44e8 | 576 | now = decrementer->next_tb - now; |
d968014b | 577 | if (now <= DECREMENTER_MAX) |
43875cc0 | 578 | set_dec((int)now); |
d968014b PM |
579 | return; |
580 | } | |
7d12e780 | 581 | old_regs = set_irq_regs(regs); |
1da177e4 LT |
582 | irq_enter(); |
583 | ||
c6622f63 | 584 | calculate_steal_time(); |
1da177e4 | 585 | |
f2783c15 | 586 | #ifdef CONFIG_PPC_ISERIES |
501b6d29 SR |
587 | if (firmware_has_feature(FW_FEATURE_ISERIES)) |
588 | get_lppaca()->int_dword.fields.decr_int = 0; | |
f2783c15 PM |
589 | #endif |
590 | ||
d831d0b8 TB |
591 | if (evt->event_handler) |
592 | evt->event_handler(evt); | |
1da177e4 LT |
593 | |
594 | #ifdef CONFIG_PPC_ISERIES | |
501b6d29 | 595 | if (firmware_has_feature(FW_FEATURE_ISERIES) && hvlpevent_is_pending()) |
35a84c2f | 596 | process_hvlpevents(); |
1da177e4 LT |
597 | #endif |
598 | ||
f2783c15 | 599 | #ifdef CONFIG_PPC64 |
8d15a3e5 | 600 | /* collect purr register values often, for accurate calculations */ |
1ababe11 | 601 | if (firmware_has_feature(FW_FEATURE_SPLPAR)) { |
1da177e4 LT |
602 | struct cpu_usage *cu = &__get_cpu_var(cpu_usage_array); |
603 | cu->current_tb = mfspr(SPRN_PURR); | |
604 | } | |
f2783c15 | 605 | #endif |
1da177e4 LT |
606 | |
607 | irq_exit(); | |
7d12e780 | 608 | set_irq_regs(old_regs); |
1da177e4 LT |
609 | } |
610 | ||
f2783c15 PM |
611 | void wakeup_decrementer(void) |
612 | { | |
092b8f34 | 613 | unsigned long ticks; |
f2783c15 | 614 | |
f2783c15 | 615 | /* |
092b8f34 PM |
616 | * The timebase gets saved on sleep and restored on wakeup, |
617 | * so all we need to do is to reset the decrementer. | |
f2783c15 | 618 | */ |
092b8f34 PM |
619 | ticks = tb_ticks_since(__get_cpu_var(last_jiffy)); |
620 | if (ticks < tb_ticks_per_jiffy) | |
621 | ticks = tb_ticks_per_jiffy - ticks; | |
622 | else | |
623 | ticks = 1; | |
624 | set_dec(ticks); | |
f2783c15 PM |
625 | } |
626 | ||
a5b518ed | 627 | #ifdef CONFIG_SMP |
f2783c15 PM |
628 | void __init smp_space_timers(unsigned int max_cpus) |
629 | { | |
630 | int i; | |
eb36c288 | 631 | u64 previous_tb = per_cpu(last_jiffy, boot_cpuid); |
f2783c15 | 632 | |
cbe62e2b PM |
633 | /* make sure tb > per_cpu(last_jiffy, cpu) for all cpus always */ |
634 | previous_tb -= tb_ticks_per_jiffy; | |
e147ec8f | 635 | |
0e551954 | 636 | for_each_possible_cpu(i) { |
c6622f63 PM |
637 | if (i == boot_cpuid) |
638 | continue; | |
e147ec8f | 639 | per_cpu(last_jiffy, i) = previous_tb; |
f2783c15 PM |
640 | } |
641 | } | |
642 | #endif | |
643 | ||
1da177e4 LT |
644 | /* |
645 | * Scheduler clock - returns current time in nanosec units. | |
646 | * | |
647 | * Note: mulhdu(a, b) (multiply high double unsigned) returns | |
648 | * the high 64 bits of a * b, i.e. (a * b) >> 64, where a and b | |
649 | * are 64-bit unsigned numbers. | |
650 | */ | |
651 | unsigned long long sched_clock(void) | |
652 | { | |
96c44507 PM |
653 | if (__USE_RTC()) |
654 | return get_rtc(); | |
fc9069fe | 655 | return mulhdu(get_tb() - boot_tb, tb_to_ns_scale) << tb_to_ns_shift; |
1da177e4 LT |
656 | } |
657 | ||
0bb474a4 | 658 | static int __init get_freq(char *name, int cells, unsigned long *val) |
10f7e7c1 AB |
659 | { |
660 | struct device_node *cpu; | |
a7f67bdf | 661 | const unsigned int *fp; |
0bb474a4 | 662 | int found = 0; |
10f7e7c1 | 663 | |
0bb474a4 | 664 | /* The cpu node should have timebase and clock frequency properties */ |
10f7e7c1 AB |
665 | cpu = of_find_node_by_type(NULL, "cpu"); |
666 | ||
d8a8188d | 667 | if (cpu) { |
e2eb6392 | 668 | fp = of_get_property(cpu, name, NULL); |
d8a8188d | 669 | if (fp) { |
0bb474a4 | 670 | found = 1; |
a4dc7ff0 | 671 | *val = of_read_ulong(fp, cells); |
10f7e7c1 | 672 | } |
0bb474a4 AB |
673 | |
674 | of_node_put(cpu); | |
10f7e7c1 | 675 | } |
0bb474a4 AB |
676 | |
677 | return found; | |
678 | } | |
679 | ||
680 | void __init generic_calibrate_decr(void) | |
681 | { | |
682 | ppc_tb_freq = DEFAULT_TB_FREQ; /* hardcoded default */ | |
683 | ||
684 | if (!get_freq("ibm,extended-timebase-frequency", 2, &ppc_tb_freq) && | |
685 | !get_freq("timebase-frequency", 1, &ppc_tb_freq)) { | |
686 | ||
10f7e7c1 AB |
687 | printk(KERN_ERR "WARNING: Estimating decrementer frequency " |
688 | "(not found)\n"); | |
0bb474a4 | 689 | } |
10f7e7c1 | 690 | |
0bb474a4 AB |
691 | ppc_proc_freq = DEFAULT_PROC_FREQ; /* hardcoded default */ |
692 | ||
693 | if (!get_freq("ibm,extended-clock-frequency", 2, &ppc_proc_freq) && | |
694 | !get_freq("clock-frequency", 1, &ppc_proc_freq)) { | |
695 | ||
696 | printk(KERN_ERR "WARNING: Estimating processor frequency " | |
697 | "(not found)\n"); | |
10f7e7c1 | 698 | } |
0bb474a4 | 699 | |
aab69292 | 700 | #if defined(CONFIG_BOOKE) || defined(CONFIG_40x) |
0fd6f717 KG |
701 | /* Set the time base to zero */ |
702 | mtspr(SPRN_TBWL, 0); | |
703 | mtspr(SPRN_TBWU, 0); | |
704 | ||
705 | /* Clear any pending timer interrupts */ | |
706 | mtspr(SPRN_TSR, TSR_ENW | TSR_WIS | TSR_DIS | TSR_FIS); | |
707 | ||
708 | /* Enable decrementer interrupt */ | |
709 | mtspr(SPRN_TCR, TCR_DIE); | |
710 | #endif | |
10f7e7c1 | 711 | } |
10f7e7c1 | 712 | |
aa3be5f3 | 713 | int update_persistent_clock(struct timespec now) |
f2783c15 PM |
714 | { |
715 | struct rtc_time tm; | |
716 | ||
aa3be5f3 TB |
717 | if (!ppc_md.set_rtc_time) |
718 | return 0; | |
719 | ||
720 | to_tm(now.tv_sec + 1 + timezone_offset, &tm); | |
721 | tm.tm_year -= 1900; | |
722 | tm.tm_mon -= 1; | |
723 | ||
724 | return ppc_md.set_rtc_time(&tm); | |
725 | } | |
726 | ||
727 | unsigned long read_persistent_clock(void) | |
728 | { | |
729 | struct rtc_time tm; | |
730 | static int first = 1; | |
731 | ||
732 | /* XXX this is a litle fragile but will work okay in the short term */ | |
733 | if (first) { | |
734 | first = 0; | |
735 | if (ppc_md.time_init) | |
736 | timezone_offset = ppc_md.time_init(); | |
737 | ||
738 | /* get_boot_time() isn't guaranteed to be safe to call late */ | |
739 | if (ppc_md.get_boot_time) | |
740 | return ppc_md.get_boot_time() -timezone_offset; | |
741 | } | |
f2783c15 PM |
742 | if (!ppc_md.get_rtc_time) |
743 | return 0; | |
744 | ppc_md.get_rtc_time(&tm); | |
745 | return mktime(tm.tm_year+1900, tm.tm_mon+1, tm.tm_mday, | |
746 | tm.tm_hour, tm.tm_min, tm.tm_sec); | |
747 | } | |
748 | ||
4a4cfe38 TB |
749 | /* clocksource code */ |
750 | static cycle_t rtc_read(void) | |
751 | { | |
752 | return (cycle_t)get_rtc(); | |
753 | } | |
754 | ||
755 | static cycle_t timebase_read(void) | |
756 | { | |
757 | return (cycle_t)get_tb(); | |
758 | } | |
759 | ||
760 | void update_vsyscall(struct timespec *wall_time, struct clocksource *clock) | |
761 | { | |
762 | u64 t2x, stamp_xsec; | |
763 | ||
764 | if (clock != &clocksource_timebase) | |
765 | return; | |
766 | ||
767 | /* Make userspace gettimeofday spin until we're done. */ | |
768 | ++vdso_data->tb_update_count; | |
769 | smp_mb(); | |
770 | ||
771 | /* XXX this assumes clock->shift == 22 */ | |
772 | /* 4611686018 ~= 2^(20+64-22) / 1e9 */ | |
773 | t2x = (u64) clock->mult * 4611686018ULL; | |
774 | stamp_xsec = (u64) xtime.tv_nsec * XSEC_PER_SEC; | |
775 | do_div(stamp_xsec, 1000000000); | |
776 | stamp_xsec += (u64) xtime.tv_sec * XSEC_PER_SEC; | |
777 | update_gtod(clock->cycle_last, stamp_xsec, t2x); | |
778 | } | |
779 | ||
780 | void update_vsyscall_tz(void) | |
781 | { | |
782 | /* Make userspace gettimeofday spin until we're done. */ | |
783 | ++vdso_data->tb_update_count; | |
784 | smp_mb(); | |
785 | vdso_data->tz_minuteswest = sys_tz.tz_minuteswest; | |
786 | vdso_data->tz_dsttime = sys_tz.tz_dsttime; | |
787 | smp_mb(); | |
788 | ++vdso_data->tb_update_count; | |
789 | } | |
790 | ||
791 | void __init clocksource_init(void) | |
792 | { | |
793 | struct clocksource *clock; | |
794 | ||
795 | if (__USE_RTC()) | |
796 | clock = &clocksource_rtc; | |
797 | else | |
798 | clock = &clocksource_timebase; | |
799 | ||
800 | clock->mult = clocksource_hz2mult(tb_ticks_per_sec, clock->shift); | |
801 | ||
802 | if (clocksource_register(clock)) { | |
803 | printk(KERN_ERR "clocksource: %s is already registered\n", | |
804 | clock->name); | |
805 | return; | |
806 | } | |
807 | ||
808 | printk(KERN_INFO "clocksource: %s mult[%x] shift[%d] registered\n", | |
809 | clock->name, clock->mult, clock->shift); | |
810 | } | |
811 | ||
d831d0b8 TB |
812 | static int decrementer_set_next_event(unsigned long evt, |
813 | struct clock_event_device *dev) | |
814 | { | |
6e6b44e8 | 815 | __get_cpu_var(decrementers).next_tb = get_tb_or_rtc() + evt; |
d831d0b8 TB |
816 | set_dec(evt); |
817 | return 0; | |
818 | } | |
819 | ||
820 | static void decrementer_set_mode(enum clock_event_mode mode, | |
821 | struct clock_event_device *dev) | |
822 | { | |
823 | if (mode != CLOCK_EVT_MODE_ONESHOT) | |
824 | decrementer_set_next_event(DECREMENTER_MAX, dev); | |
825 | } | |
826 | ||
827 | static void register_decrementer_clockevent(int cpu) | |
828 | { | |
6e6b44e8 | 829 | struct clock_event_device *dec = &per_cpu(decrementers, cpu).event; |
d831d0b8 TB |
830 | |
831 | *dec = decrementer_clockevent; | |
832 | dec->cpumask = cpumask_of_cpu(cpu); | |
833 | ||
0302f12e | 834 | printk(KERN_DEBUG "clockevent: %s mult[%lx] shift[%d] cpu[%d]\n", |
d831d0b8 TB |
835 | dec->name, dec->mult, dec->shift, cpu); |
836 | ||
837 | clockevents_register_device(dec); | |
838 | } | |
839 | ||
c481887f | 840 | static void __init init_decrementer_clockevent(void) |
d831d0b8 TB |
841 | { |
842 | int cpu = smp_processor_id(); | |
843 | ||
844 | decrementer_clockevent.mult = div_sc(ppc_tb_freq, NSEC_PER_SEC, | |
845 | decrementer_clockevent.shift); | |
846 | decrementer_clockevent.max_delta_ns = | |
847 | clockevent_delta2ns(DECREMENTER_MAX, &decrementer_clockevent); | |
43875cc0 PM |
848 | decrementer_clockevent.min_delta_ns = |
849 | clockevent_delta2ns(2, &decrementer_clockevent); | |
d831d0b8 TB |
850 | |
851 | register_decrementer_clockevent(cpu); | |
852 | } | |
853 | ||
854 | void secondary_cpu_time_init(void) | |
855 | { | |
856 | /* FIME: Should make unrelatred change to move snapshot_timebase | |
857 | * call here ! */ | |
858 | register_decrementer_clockevent(smp_processor_id()); | |
859 | } | |
860 | ||
f2783c15 | 861 | /* This function is only called on the boot processor */ |
1da177e4 LT |
862 | void __init time_init(void) |
863 | { | |
1da177e4 | 864 | unsigned long flags; |
1da177e4 | 865 | struct div_result res; |
092b8f34 | 866 | u64 scale, x; |
f2783c15 PM |
867 | unsigned shift; |
868 | ||
96c44507 PM |
869 | if (__USE_RTC()) { |
870 | /* 601 processor: dec counts down by 128 every 128ns */ | |
871 | ppc_tb_freq = 1000000000; | |
eb36c288 | 872 | tb_last_jiffy = get_rtcl(); |
96c44507 PM |
873 | } else { |
874 | /* Normal PowerPC with timebase register */ | |
875 | ppc_md.calibrate_decr(); | |
224ad80a | 876 | printk(KERN_DEBUG "time_init: decrementer frequency = %lu.%.6lu MHz\n", |
96c44507 | 877 | ppc_tb_freq / 1000000, ppc_tb_freq % 1000000); |
224ad80a | 878 | printk(KERN_DEBUG "time_init: processor frequency = %lu.%.6lu MHz\n", |
96c44507 | 879 | ppc_proc_freq / 1000000, ppc_proc_freq % 1000000); |
eb36c288 | 880 | tb_last_jiffy = get_tb(); |
96c44507 | 881 | } |
374e99d4 PM |
882 | |
883 | tb_ticks_per_jiffy = ppc_tb_freq / HZ; | |
092b8f34 | 884 | tb_ticks_per_sec = ppc_tb_freq; |
374e99d4 PM |
885 | tb_ticks_per_usec = ppc_tb_freq / 1000000; |
886 | tb_to_us = mulhwu_scale_factor(ppc_tb_freq, 1000000); | |
c6622f63 | 887 | calc_cputime_factors(); |
092b8f34 PM |
888 | |
889 | /* | |
890 | * Calculate the length of each tick in ns. It will not be | |
891 | * exactly 1e9/HZ unless ppc_tb_freq is divisible by HZ. | |
892 | * We compute 1e9 * tb_ticks_per_jiffy / ppc_tb_freq, | |
893 | * rounded up. | |
894 | */ | |
895 | x = (u64) NSEC_PER_SEC * tb_ticks_per_jiffy + ppc_tb_freq - 1; | |
896 | do_div(x, ppc_tb_freq); | |
897 | tick_nsec = x; | |
898 | last_tick_len = x << TICKLEN_SCALE; | |
899 | ||
900 | /* | |
901 | * Compute ticklen_to_xs, which is a factor which gets multiplied | |
902 | * by (last_tick_len << TICKLEN_SHIFT) to get a tb_to_xs value. | |
903 | * It is computed as: | |
904 | * ticklen_to_xs = 2^N / (tb_ticks_per_jiffy * 1e9) | |
905 | * where N = 64 + 20 - TICKLEN_SCALE - TICKLEN_SHIFT | |
0a45d449 PM |
906 | * which turns out to be N = 51 - SHIFT_HZ. |
907 | * This gives the result as a 0.64 fixed-point fraction. | |
908 | * That value is reduced by an offset amounting to 1 xsec per | |
909 | * 2^31 timebase ticks to avoid problems with time going backwards | |
910 | * by 1 xsec when we do timer_recalc_offset due to losing the | |
911 | * fractional xsec. That offset is equal to ppc_tb_freq/2^51 | |
912 | * since there are 2^20 xsec in a second. | |
092b8f34 | 913 | */ |
0a45d449 PM |
914 | div128_by_32((1ULL << 51) - ppc_tb_freq, 0, |
915 | tb_ticks_per_jiffy << SHIFT_HZ, &res); | |
092b8f34 PM |
916 | div128_by_32(res.result_high, res.result_low, NSEC_PER_SEC, &res); |
917 | ticklen_to_xs = res.result_low; | |
918 | ||
919 | /* Compute tb_to_xs from tick_nsec */ | |
920 | tb_to_xs = mulhdu(last_tick_len << TICKLEN_SHIFT, ticklen_to_xs); | |
374e99d4 | 921 | |
1da177e4 LT |
922 | /* |
923 | * Compute scale factor for sched_clock. | |
924 | * The calibrate_decr() function has set tb_ticks_per_sec, | |
925 | * which is the timebase frequency. | |
926 | * We compute 1e9 * 2^64 / tb_ticks_per_sec and interpret | |
927 | * the 128-bit result as a 64.64 fixed-point number. | |
928 | * We then shift that number right until it is less than 1.0, | |
929 | * giving us the scale factor and shift count to use in | |
930 | * sched_clock(). | |
931 | */ | |
932 | div128_by_32(1000000000, 0, tb_ticks_per_sec, &res); | |
933 | scale = res.result_low; | |
934 | for (shift = 0; res.result_high != 0; ++shift) { | |
935 | scale = (scale >> 1) | (res.result_high << 63); | |
936 | res.result_high >>= 1; | |
937 | } | |
938 | tb_to_ns_scale = scale; | |
939 | tb_to_ns_shift = shift; | |
fc9069fe | 940 | /* Save the current timebase to pretty up CONFIG_PRINTK_TIME */ |
c27da339 | 941 | boot_tb = get_tb_or_rtc(); |
1da177e4 | 942 | |
1da177e4 | 943 | write_seqlock_irqsave(&xtime_lock, flags); |
092b8f34 PM |
944 | |
945 | /* If platform provided a timezone (pmac), we correct the time */ | |
946 | if (timezone_offset) { | |
947 | sys_tz.tz_minuteswest = -timezone_offset / 60; | |
948 | sys_tz.tz_dsttime = 0; | |
092b8f34 PM |
949 | } |
950 | ||
1da177e4 LT |
951 | do_gtod.varp = &do_gtod.vars[0]; |
952 | do_gtod.var_idx = 0; | |
96c44507 | 953 | do_gtod.varp->tb_orig_stamp = tb_last_jiffy; |
eb36c288 | 954 | __get_cpu_var(last_jiffy) = tb_last_jiffy; |
f2783c15 | 955 | do_gtod.varp->stamp_xsec = (u64) xtime.tv_sec * XSEC_PER_SEC; |
1da177e4 LT |
956 | do_gtod.tb_ticks_per_sec = tb_ticks_per_sec; |
957 | do_gtod.varp->tb_to_xs = tb_to_xs; | |
958 | do_gtod.tb_to_us = tb_to_us; | |
a7f290da BH |
959 | |
960 | vdso_data->tb_orig_stamp = tb_last_jiffy; | |
961 | vdso_data->tb_update_count = 0; | |
962 | vdso_data->tb_ticks_per_sec = tb_ticks_per_sec; | |
092b8f34 | 963 | vdso_data->stamp_xsec = (u64) xtime.tv_sec * XSEC_PER_SEC; |
a7f290da | 964 | vdso_data->tb_to_xs = tb_to_xs; |
1da177e4 LT |
965 | |
966 | time_freq = 0; | |
967 | ||
1da177e4 LT |
968 | write_sequnlock_irqrestore(&xtime_lock, flags); |
969 | ||
4a4cfe38 TB |
970 | /* Register the clocksource, if we're not running on iSeries */ |
971 | if (!firmware_has_feature(FW_FEATURE_ISERIES)) | |
972 | clocksource_init(); | |
973 | ||
d831d0b8 | 974 | init_decrementer_clockevent(); |
1da177e4 LT |
975 | } |
976 | ||
1da177e4 | 977 | |
1da177e4 LT |
978 | #define FEBRUARY 2 |
979 | #define STARTOFTIME 1970 | |
980 | #define SECDAY 86400L | |
981 | #define SECYR (SECDAY * 365) | |
f2783c15 PM |
982 | #define leapyear(year) ((year) % 4 == 0 && \ |
983 | ((year) % 100 != 0 || (year) % 400 == 0)) | |
1da177e4 LT |
984 | #define days_in_year(a) (leapyear(a) ? 366 : 365) |
985 | #define days_in_month(a) (month_days[(a) - 1]) | |
986 | ||
987 | static int month_days[12] = { | |
988 | 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 | |
989 | }; | |
990 | ||
991 | /* | |
992 | * This only works for the Gregorian calendar - i.e. after 1752 (in the UK) | |
993 | */ | |
994 | void GregorianDay(struct rtc_time * tm) | |
995 | { | |
996 | int leapsToDate; | |
997 | int lastYear; | |
998 | int day; | |
999 | int MonthOffset[] = { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 }; | |
1000 | ||
f2783c15 | 1001 | lastYear = tm->tm_year - 1; |
1da177e4 LT |
1002 | |
1003 | /* | |
1004 | * Number of leap corrections to apply up to end of last year | |
1005 | */ | |
f2783c15 | 1006 | leapsToDate = lastYear / 4 - lastYear / 100 + lastYear / 400; |
1da177e4 LT |
1007 | |
1008 | /* | |
1009 | * This year is a leap year if it is divisible by 4 except when it is | |
1010 | * divisible by 100 unless it is divisible by 400 | |
1011 | * | |
f2783c15 | 1012 | * e.g. 1904 was a leap year, 1900 was not, 1996 is, and 2000 was |
1da177e4 | 1013 | */ |
f2783c15 | 1014 | day = tm->tm_mon > 2 && leapyear(tm->tm_year); |
1da177e4 LT |
1015 | |
1016 | day += lastYear*365 + leapsToDate + MonthOffset[tm->tm_mon-1] + | |
1017 | tm->tm_mday; | |
1018 | ||
f2783c15 | 1019 | tm->tm_wday = day % 7; |
1da177e4 LT |
1020 | } |
1021 | ||
1022 | void to_tm(int tim, struct rtc_time * tm) | |
1023 | { | |
1024 | register int i; | |
1025 | register long hms, day; | |
1026 | ||
1027 | day = tim / SECDAY; | |
1028 | hms = tim % SECDAY; | |
1029 | ||
1030 | /* Hours, minutes, seconds are easy */ | |
1031 | tm->tm_hour = hms / 3600; | |
1032 | tm->tm_min = (hms % 3600) / 60; | |
1033 | tm->tm_sec = (hms % 3600) % 60; | |
1034 | ||
1035 | /* Number of years in days */ | |
1036 | for (i = STARTOFTIME; day >= days_in_year(i); i++) | |
1037 | day -= days_in_year(i); | |
1038 | tm->tm_year = i; | |
1039 | ||
1040 | /* Number of months in days left */ | |
1041 | if (leapyear(tm->tm_year)) | |
1042 | days_in_month(FEBRUARY) = 29; | |
1043 | for (i = 1; day >= days_in_month(i); i++) | |
1044 | day -= days_in_month(i); | |
1045 | days_in_month(FEBRUARY) = 28; | |
1046 | tm->tm_mon = i; | |
1047 | ||
1048 | /* Days are what is left over (+1) from all that. */ | |
1049 | tm->tm_mday = day + 1; | |
1050 | ||
1051 | /* | |
1052 | * Determine the day of week | |
1053 | */ | |
1054 | GregorianDay(tm); | |
1055 | } | |
1056 | ||
1057 | /* Auxiliary function to compute scaling factors */ | |
1058 | /* Actually the choice of a timebase running at 1/4 the of the bus | |
1059 | * frequency giving resolution of a few tens of nanoseconds is quite nice. | |
1060 | * It makes this computation very precise (27-28 bits typically) which | |
1061 | * is optimistic considering the stability of most processor clock | |
1062 | * oscillators and the precision with which the timebase frequency | |
1063 | * is measured but does not harm. | |
1064 | */ | |
f2783c15 PM |
1065 | unsigned mulhwu_scale_factor(unsigned inscale, unsigned outscale) |
1066 | { | |
1da177e4 LT |
1067 | unsigned mlt=0, tmp, err; |
1068 | /* No concern for performance, it's done once: use a stupid | |
1069 | * but safe and compact method to find the multiplier. | |
1070 | */ | |
1071 | ||
1072 | for (tmp = 1U<<31; tmp != 0; tmp >>= 1) { | |
f2783c15 PM |
1073 | if (mulhwu(inscale, mlt|tmp) < outscale) |
1074 | mlt |= tmp; | |
1da177e4 LT |
1075 | } |
1076 | ||
1077 | /* We might still be off by 1 for the best approximation. | |
1078 | * A side effect of this is that if outscale is too large | |
1079 | * the returned value will be zero. | |
1080 | * Many corner cases have been checked and seem to work, | |
1081 | * some might have been forgotten in the test however. | |
1082 | */ | |
1083 | ||
f2783c15 PM |
1084 | err = inscale * (mlt+1); |
1085 | if (err <= inscale/2) | |
1086 | mlt++; | |
1da177e4 | 1087 | return mlt; |
f2783c15 | 1088 | } |
1da177e4 LT |
1089 | |
1090 | /* | |
1091 | * Divide a 128-bit dividend by a 32-bit divisor, leaving a 128 bit | |
1092 | * result. | |
1093 | */ | |
f2783c15 PM |
1094 | void div128_by_32(u64 dividend_high, u64 dividend_low, |
1095 | unsigned divisor, struct div_result *dr) | |
1da177e4 | 1096 | { |
f2783c15 PM |
1097 | unsigned long a, b, c, d; |
1098 | unsigned long w, x, y, z; | |
1099 | u64 ra, rb, rc; | |
1da177e4 LT |
1100 | |
1101 | a = dividend_high >> 32; | |
1102 | b = dividend_high & 0xffffffff; | |
1103 | c = dividend_low >> 32; | |
1104 | d = dividend_low & 0xffffffff; | |
1105 | ||
f2783c15 PM |
1106 | w = a / divisor; |
1107 | ra = ((u64)(a - (w * divisor)) << 32) + b; | |
1108 | ||
f2783c15 PM |
1109 | rb = ((u64) do_div(ra, divisor) << 32) + c; |
1110 | x = ra; | |
1da177e4 | 1111 | |
f2783c15 PM |
1112 | rc = ((u64) do_div(rb, divisor) << 32) + d; |
1113 | y = rb; | |
1114 | ||
1115 | do_div(rc, divisor); | |
1116 | z = rc; | |
1da177e4 | 1117 | |
f2783c15 PM |
1118 | dr->result_high = ((u64)w << 32) + x; |
1119 | dr->result_low = ((u64)y << 32) + z; | |
1da177e4 LT |
1120 | |
1121 | } |