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> |
177996e6 | 55 | #include <linux/delay.h> |
e360adbe | 56 | #include <linux/irq_work.h> |
6795b85c | 57 | #include <asm/trace.h> |
1da177e4 | 58 | |
1da177e4 LT |
59 | #include <asm/io.h> |
60 | #include <asm/processor.h> | |
61 | #include <asm/nvram.h> | |
62 | #include <asm/cache.h> | |
63 | #include <asm/machdep.h> | |
1da177e4 LT |
64 | #include <asm/uaccess.h> |
65 | #include <asm/time.h> | |
1da177e4 | 66 | #include <asm/prom.h> |
f2783c15 PM |
67 | #include <asm/irq.h> |
68 | #include <asm/div64.h> | |
2249ca9d | 69 | #include <asm/smp.h> |
a7f290da | 70 | #include <asm/vdso_datapage.h> |
1ababe11 | 71 | #include <asm/firmware.h> |
06b8e878 | 72 | #include <asm/cputime.h> |
f2783c15 | 73 | #ifdef CONFIG_PPC_ISERIES |
8875ccfb | 74 | #include <asm/iseries/it_lp_queue.h> |
8021b8a7 | 75 | #include <asm/iseries/hv_call_xm.h> |
f2783c15 | 76 | #endif |
1da177e4 | 77 | |
4a4cfe38 TB |
78 | /* powerpc clocksource/clockevent code */ |
79 | ||
d831d0b8 | 80 | #include <linux/clockchips.h> |
4a4cfe38 TB |
81 | #include <linux/clocksource.h> |
82 | ||
8e19608e | 83 | static cycle_t rtc_read(struct clocksource *); |
4a4cfe38 TB |
84 | static struct clocksource clocksource_rtc = { |
85 | .name = "rtc", | |
86 | .rating = 400, | |
87 | .flags = CLOCK_SOURCE_IS_CONTINUOUS, | |
88 | .mask = CLOCKSOURCE_MASK(64), | |
89 | .shift = 22, | |
90 | .mult = 0, /* To be filled in */ | |
91 | .read = rtc_read, | |
92 | }; | |
93 | ||
8e19608e | 94 | static cycle_t timebase_read(struct clocksource *); |
4a4cfe38 TB |
95 | static struct clocksource clocksource_timebase = { |
96 | .name = "timebase", | |
97 | .rating = 400, | |
98 | .flags = CLOCK_SOURCE_IS_CONTINUOUS, | |
99 | .mask = CLOCKSOURCE_MASK(64), | |
100 | .shift = 22, | |
101 | .mult = 0, /* To be filled in */ | |
102 | .read = timebase_read, | |
103 | }; | |
104 | ||
d831d0b8 TB |
105 | #define DECREMENTER_MAX 0x7fffffff |
106 | ||
107 | static int decrementer_set_next_event(unsigned long evt, | |
108 | struct clock_event_device *dev); | |
109 | static void decrementer_set_mode(enum clock_event_mode mode, | |
110 | struct clock_event_device *dev); | |
111 | ||
112 | static struct clock_event_device decrementer_clockevent = { | |
113 | .name = "decrementer", | |
114 | .rating = 200, | |
8d165db1 | 115 | .shift = 0, /* To be filled in */ |
d831d0b8 TB |
116 | .mult = 0, /* To be filled in */ |
117 | .irq = 0, | |
118 | .set_next_event = decrementer_set_next_event, | |
119 | .set_mode = decrementer_set_mode, | |
120 | .features = CLOCK_EVT_FEAT_ONESHOT, | |
121 | }; | |
122 | ||
6e6b44e8 MM |
123 | struct decrementer_clock { |
124 | struct clock_event_device event; | |
125 | u64 next_tb; | |
126 | }; | |
127 | ||
128 | static DEFINE_PER_CPU(struct decrementer_clock, decrementers); | |
d831d0b8 | 129 | |
1da177e4 | 130 | #ifdef CONFIG_PPC_ISERIES |
71712b45 TB |
131 | static unsigned long __initdata iSeries_recal_titan; |
132 | static signed long __initdata iSeries_recal_tb; | |
4a4cfe38 TB |
133 | |
134 | /* Forward declaration is only needed for iSereis compiles */ | |
1c21a293 | 135 | static void __init clocksource_init(void); |
1da177e4 LT |
136 | #endif |
137 | ||
138 | #define XSEC_PER_SEC (1024*1024) | |
139 | ||
f2783c15 PM |
140 | #ifdef CONFIG_PPC64 |
141 | #define SCALE_XSEC(xsec, max) (((xsec) * max) / XSEC_PER_SEC) | |
142 | #else | |
143 | /* compute ((xsec << 12) * max) >> 32 */ | |
144 | #define SCALE_XSEC(xsec, max) mulhwu((xsec) << 12, max) | |
145 | #endif | |
146 | ||
1da177e4 LT |
147 | unsigned long tb_ticks_per_jiffy; |
148 | unsigned long tb_ticks_per_usec = 100; /* sane default */ | |
149 | EXPORT_SYMBOL(tb_ticks_per_usec); | |
150 | unsigned long tb_ticks_per_sec; | |
2cf82c02 | 151 | EXPORT_SYMBOL(tb_ticks_per_sec); /* for cputime_t conversions */ |
092b8f34 | 152 | |
1da177e4 | 153 | DEFINE_SPINLOCK(rtc_lock); |
6ae3db11 | 154 | EXPORT_SYMBOL_GPL(rtc_lock); |
1da177e4 | 155 | |
fc9069fe TB |
156 | static u64 tb_to_ns_scale __read_mostly; |
157 | static unsigned tb_to_ns_shift __read_mostly; | |
158 | static unsigned long boot_tb __read_mostly; | |
1da177e4 | 159 | |
1da177e4 | 160 | extern struct timezone sys_tz; |
f2783c15 | 161 | static long timezone_offset; |
1da177e4 | 162 | |
10f7e7c1 | 163 | unsigned long ppc_proc_freq; |
1474855d | 164 | EXPORT_SYMBOL(ppc_proc_freq); |
10f7e7c1 AB |
165 | unsigned long ppc_tb_freq; |
166 | ||
eb36c288 | 167 | static DEFINE_PER_CPU(u64, last_jiffy); |
96c44507 | 168 | |
c6622f63 PM |
169 | #ifdef CONFIG_VIRT_CPU_ACCOUNTING |
170 | /* | |
171 | * Factors for converting from cputime_t (timebase ticks) to | |
172 | * jiffies, milliseconds, seconds, and clock_t (1/USER_HZ seconds). | |
173 | * These are all stored as 0.64 fixed-point binary fractions. | |
174 | */ | |
175 | u64 __cputime_jiffies_factor; | |
2cf82c02 | 176 | EXPORT_SYMBOL(__cputime_jiffies_factor); |
c6622f63 | 177 | u64 __cputime_msec_factor; |
2cf82c02 | 178 | EXPORT_SYMBOL(__cputime_msec_factor); |
c6622f63 | 179 | u64 __cputime_sec_factor; |
2cf82c02 | 180 | EXPORT_SYMBOL(__cputime_sec_factor); |
c6622f63 | 181 | u64 __cputime_clockt_factor; |
2cf82c02 | 182 | EXPORT_SYMBOL(__cputime_clockt_factor); |
06b8e878 MN |
183 | DEFINE_PER_CPU(unsigned long, cputime_last_delta); |
184 | DEFINE_PER_CPU(unsigned long, cputime_scaled_last_delta); | |
c6622f63 | 185 | |
a42548a1 SG |
186 | cputime_t cputime_one_jiffy; |
187 | ||
c6622f63 PM |
188 | static void calc_cputime_factors(void) |
189 | { | |
190 | struct div_result res; | |
191 | ||
192 | div128_by_32(HZ, 0, tb_ticks_per_sec, &res); | |
193 | __cputime_jiffies_factor = res.result_low; | |
194 | div128_by_32(1000, 0, tb_ticks_per_sec, &res); | |
195 | __cputime_msec_factor = res.result_low; | |
196 | div128_by_32(1, 0, tb_ticks_per_sec, &res); | |
197 | __cputime_sec_factor = res.result_low; | |
198 | div128_by_32(USER_HZ, 0, tb_ticks_per_sec, &res); | |
199 | __cputime_clockt_factor = res.result_low; | |
200 | } | |
201 | ||
202 | /* | |
203 | * Read the PURR on systems that have it, otherwise the timebase. | |
204 | */ | |
205 | static u64 read_purr(void) | |
206 | { | |
207 | if (cpu_has_feature(CPU_FTR_PURR)) | |
208 | return mfspr(SPRN_PURR); | |
209 | return mftb(); | |
210 | } | |
211 | ||
4603ac18 MN |
212 | /* |
213 | * Read the SPURR on systems that have it, otherwise the purr | |
214 | */ | |
215 | static u64 read_spurr(u64 purr) | |
216 | { | |
53024fe2 MM |
217 | /* |
218 | * cpus without PURR won't have a SPURR | |
219 | * We already know the former when we use this, so tell gcc | |
220 | */ | |
221 | if (cpu_has_feature(CPU_FTR_PURR) && cpu_has_feature(CPU_FTR_SPURR)) | |
4603ac18 MN |
222 | return mfspr(SPRN_SPURR); |
223 | return purr; | |
224 | } | |
225 | ||
c6622f63 PM |
226 | /* |
227 | * Account time for a transition between system, hard irq | |
228 | * or soft irq state. | |
229 | */ | |
230 | void account_system_vtime(struct task_struct *tsk) | |
231 | { | |
53024fe2 | 232 | u64 now, nowscaled, delta, deltascaled, sys_time; |
c6622f63 PM |
233 | unsigned long flags; |
234 | ||
235 | local_irq_save(flags); | |
236 | now = read_purr(); | |
4603ac18 | 237 | nowscaled = read_spurr(now); |
53024fe2 | 238 | delta = now - get_paca()->startpurr; |
4603ac18 | 239 | deltascaled = nowscaled - get_paca()->startspurr; |
53024fe2 | 240 | get_paca()->startpurr = now; |
4603ac18 | 241 | get_paca()->startspurr = nowscaled; |
c6622f63 | 242 | if (!in_interrupt()) { |
4603ac18 MN |
243 | /* deltascaled includes both user and system time. |
244 | * Hence scale it based on the purr ratio to estimate | |
245 | * the system time */ | |
53024fe2 | 246 | sys_time = get_paca()->system_time; |
2b46b567 | 247 | if (get_paca()->user_time) |
53024fe2 MM |
248 | deltascaled = deltascaled * sys_time / |
249 | (sys_time + get_paca()->user_time); | |
250 | delta += sys_time; | |
c6622f63 PM |
251 | get_paca()->system_time = 0; |
252 | } | |
79741dd3 MS |
253 | if (in_irq() || idle_task(smp_processor_id()) != tsk) |
254 | account_system_time(tsk, 0, delta, deltascaled); | |
255 | else | |
256 | account_idle_time(delta); | |
61c03ddb AB |
257 | __get_cpu_var(cputime_last_delta) = delta; |
258 | __get_cpu_var(cputime_scaled_last_delta) = deltascaled; | |
c6622f63 PM |
259 | local_irq_restore(flags); |
260 | } | |
4ab79aa8 | 261 | EXPORT_SYMBOL_GPL(account_system_vtime); |
c6622f63 PM |
262 | |
263 | /* | |
264 | * Transfer the user and system times accumulated in the paca | |
265 | * by the exception entry and exit code to the generic process | |
266 | * user and system time records. | |
267 | * Must be called with interrupts disabled. | |
268 | */ | |
fa13a5a1 | 269 | void account_process_tick(struct task_struct *tsk, int user_tick) |
c6622f63 | 270 | { |
4603ac18 | 271 | cputime_t utime, utimescaled; |
c6622f63 PM |
272 | |
273 | utime = get_paca()->user_time; | |
274 | get_paca()->user_time = 0; | |
06b8e878 | 275 | utimescaled = cputime_to_scaled(utime); |
457533a7 | 276 | account_user_time(tsk, utime, utimescaled); |
c6622f63 PM |
277 | } |
278 | ||
c6622f63 PM |
279 | /* |
280 | * Stuff for accounting stolen time. | |
281 | */ | |
282 | struct cpu_purr_data { | |
283 | int initialized; /* thread is running */ | |
c6622f63 PM |
284 | u64 tb; /* last TB value read */ |
285 | u64 purr; /* last PURR value read */ | |
4603ac18 | 286 | u64 spurr; /* last SPURR value read */ |
c6622f63 PM |
287 | }; |
288 | ||
df211c8a NL |
289 | /* |
290 | * Each entry in the cpu_purr_data array is manipulated only by its | |
291 | * "owner" cpu -- usually in the timer interrupt but also occasionally | |
292 | * in process context for cpu online. As long as cpus do not touch | |
293 | * each others' cpu_purr_data, disabling local interrupts is | |
294 | * sufficient to serialize accesses. | |
295 | */ | |
c6622f63 PM |
296 | static DEFINE_PER_CPU(struct cpu_purr_data, cpu_purr_data); |
297 | ||
298 | static void snapshot_tb_and_purr(void *data) | |
299 | { | |
df211c8a | 300 | unsigned long flags; |
c6622f63 PM |
301 | struct cpu_purr_data *p = &__get_cpu_var(cpu_purr_data); |
302 | ||
df211c8a | 303 | local_irq_save(flags); |
c27da339 | 304 | p->tb = get_tb_or_rtc(); |
cbcdb93d | 305 | p->purr = mfspr(SPRN_PURR); |
c6622f63 PM |
306 | wmb(); |
307 | p->initialized = 1; | |
df211c8a | 308 | local_irq_restore(flags); |
c6622f63 PM |
309 | } |
310 | ||
311 | /* | |
312 | * Called during boot when all cpus have come up. | |
313 | */ | |
314 | void snapshot_timebases(void) | |
315 | { | |
c6622f63 PM |
316 | if (!cpu_has_feature(CPU_FTR_PURR)) |
317 | return; | |
15c8b6c1 | 318 | on_each_cpu(snapshot_tb_and_purr, NULL, 1); |
c6622f63 PM |
319 | } |
320 | ||
df211c8a NL |
321 | /* |
322 | * Must be called with interrupts disabled. | |
323 | */ | |
c6622f63 PM |
324 | void calculate_steal_time(void) |
325 | { | |
cbcdb93d | 326 | u64 tb, purr; |
c6622f63 | 327 | s64 stolen; |
cbcdb93d | 328 | struct cpu_purr_data *pme; |
c6622f63 | 329 | |
8b5621f1 | 330 | pme = &__get_cpu_var(cpu_purr_data); |
c6622f63 | 331 | if (!pme->initialized) |
db3801a8 | 332 | return; /* !CPU_FTR_PURR or early in early boot */ |
c6622f63 | 333 | tb = mftb(); |
cbcdb93d SR |
334 | purr = mfspr(SPRN_PURR); |
335 | stolen = (tb - pme->tb) - (purr - pme->purr); | |
79741dd3 MS |
336 | if (stolen > 0) { |
337 | if (idle_task(smp_processor_id()) != current) | |
338 | account_steal_time(stolen); | |
339 | else | |
340 | account_idle_time(stolen); | |
341 | } | |
c6622f63 PM |
342 | pme->tb = tb; |
343 | pme->purr = purr; | |
c6622f63 PM |
344 | } |
345 | ||
4cefebb1 | 346 | #ifdef CONFIG_PPC_SPLPAR |
c6622f63 PM |
347 | /* |
348 | * Must be called before the cpu is added to the online map when | |
349 | * a cpu is being brought up at runtime. | |
350 | */ | |
351 | static void snapshot_purr(void) | |
352 | { | |
cbcdb93d | 353 | struct cpu_purr_data *pme; |
c6622f63 PM |
354 | unsigned long flags; |
355 | ||
356 | if (!cpu_has_feature(CPU_FTR_PURR)) | |
357 | return; | |
df211c8a | 358 | local_irq_save(flags); |
8b5621f1 | 359 | pme = &__get_cpu_var(cpu_purr_data); |
cbcdb93d SR |
360 | pme->tb = mftb(); |
361 | pme->purr = mfspr(SPRN_PURR); | |
c6622f63 | 362 | pme->initialized = 1; |
df211c8a | 363 | local_irq_restore(flags); |
c6622f63 PM |
364 | } |
365 | ||
366 | #endif /* CONFIG_PPC_SPLPAR */ | |
367 | ||
368 | #else /* ! CONFIG_VIRT_CPU_ACCOUNTING */ | |
369 | #define calc_cputime_factors() | |
c6622f63 PM |
370 | #define calculate_steal_time() do { } while (0) |
371 | #endif | |
372 | ||
373 | #if !(defined(CONFIG_VIRT_CPU_ACCOUNTING) && defined(CONFIG_PPC_SPLPAR)) | |
374 | #define snapshot_purr() do { } while (0) | |
375 | #endif | |
376 | ||
377 | /* | |
378 | * Called when a cpu comes up after the system has finished booting, | |
379 | * i.e. as a result of a hotplug cpu action. | |
380 | */ | |
381 | void snapshot_timebase(void) | |
382 | { | |
c27da339 | 383 | __get_cpu_var(last_jiffy) = get_tb_or_rtc(); |
c6622f63 PM |
384 | snapshot_purr(); |
385 | } | |
386 | ||
6defa38b PM |
387 | void __delay(unsigned long loops) |
388 | { | |
389 | unsigned long start; | |
390 | int diff; | |
391 | ||
392 | if (__USE_RTC()) { | |
393 | start = get_rtcl(); | |
394 | do { | |
395 | /* the RTCL register wraps at 1000000000 */ | |
396 | diff = get_rtcl() - start; | |
397 | if (diff < 0) | |
398 | diff += 1000000000; | |
399 | } while (diff < loops); | |
400 | } else { | |
401 | start = get_tbl(); | |
402 | while (get_tbl() - start < loops) | |
403 | HMT_low(); | |
404 | HMT_medium(); | |
405 | } | |
406 | } | |
407 | EXPORT_SYMBOL(__delay); | |
408 | ||
409 | void udelay(unsigned long usecs) | |
410 | { | |
411 | __delay(tb_ticks_per_usec * usecs); | |
412 | } | |
413 | EXPORT_SYMBOL(udelay); | |
414 | ||
1da177e4 LT |
415 | #ifdef CONFIG_SMP |
416 | unsigned long profile_pc(struct pt_regs *regs) | |
417 | { | |
418 | unsigned long pc = instruction_pointer(regs); | |
419 | ||
420 | if (in_lock_functions(pc)) | |
421 | return regs->link; | |
422 | ||
423 | return pc; | |
424 | } | |
425 | EXPORT_SYMBOL(profile_pc); | |
426 | #endif | |
427 | ||
428 | #ifdef CONFIG_PPC_ISERIES | |
429 | ||
430 | /* | |
431 | * This function recalibrates the timebase based on the 49-bit time-of-day | |
432 | * value in the Titan chip. The Titan is much more accurate than the value | |
433 | * returned by the service processor for the timebase frequency. | |
434 | */ | |
435 | ||
71712b45 | 436 | static int __init iSeries_tb_recal(void) |
1da177e4 | 437 | { |
1da177e4 | 438 | unsigned long titan, tb; |
71712b45 TB |
439 | |
440 | /* Make sure we only run on iSeries */ | |
441 | if (!firmware_has_feature(FW_FEATURE_ISERIES)) | |
442 | return -ENODEV; | |
443 | ||
1da177e4 LT |
444 | tb = get_tb(); |
445 | titan = HvCallXm_loadTod(); | |
446 | if ( iSeries_recal_titan ) { | |
447 | unsigned long tb_ticks = tb - iSeries_recal_tb; | |
448 | unsigned long titan_usec = (titan - iSeries_recal_titan) >> 12; | |
449 | unsigned long new_tb_ticks_per_sec = (tb_ticks * USEC_PER_SEC)/titan_usec; | |
14ea58ad JL |
450 | unsigned long new_tb_ticks_per_jiffy = |
451 | DIV_ROUND_CLOSEST(new_tb_ticks_per_sec, HZ); | |
1da177e4 LT |
452 | long tick_diff = new_tb_ticks_per_jiffy - tb_ticks_per_jiffy; |
453 | char sign = '+'; | |
454 | /* make sure tb_ticks_per_sec and tb_ticks_per_jiffy are consistent */ | |
455 | new_tb_ticks_per_sec = new_tb_ticks_per_jiffy * HZ; | |
456 | ||
457 | if ( tick_diff < 0 ) { | |
458 | tick_diff = -tick_diff; | |
459 | sign = '-'; | |
460 | } | |
461 | if ( tick_diff ) { | |
462 | if ( tick_diff < tb_ticks_per_jiffy/25 ) { | |
463 | printk( "Titan recalibrate: new tb_ticks_per_jiffy = %lu (%c%ld)\n", | |
464 | new_tb_ticks_per_jiffy, sign, tick_diff ); | |
465 | tb_ticks_per_jiffy = new_tb_ticks_per_jiffy; | |
466 | tb_ticks_per_sec = new_tb_ticks_per_sec; | |
c6622f63 | 467 | calc_cputime_factors(); |
a7f290da | 468 | vdso_data->tb_ticks_per_sec = tb_ticks_per_sec; |
a42548a1 | 469 | setup_cputime_one_jiffy(); |
1da177e4 LT |
470 | } |
471 | else { | |
472 | printk( "Titan recalibrate: FAILED (difference > 4 percent)\n" | |
473 | " new tb_ticks_per_jiffy = %lu\n" | |
474 | " old tb_ticks_per_jiffy = %lu\n", | |
475 | new_tb_ticks_per_jiffy, tb_ticks_per_jiffy ); | |
476 | } | |
477 | } | |
478 | } | |
479 | iSeries_recal_titan = titan; | |
480 | iSeries_recal_tb = tb; | |
71712b45 | 481 | |
4a4cfe38 TB |
482 | /* Called here as now we know accurate values for the timebase */ |
483 | clocksource_init(); | |
71712b45 | 484 | return 0; |
1da177e4 | 485 | } |
71712b45 TB |
486 | late_initcall(iSeries_tb_recal); |
487 | ||
488 | /* Called from platform early init */ | |
489 | void __init iSeries_time_init_early(void) | |
490 | { | |
491 | iSeries_recal_tb = get_tb(); | |
492 | iSeries_recal_titan = HvCallXm_loadTod(); | |
493 | } | |
494 | #endif /* CONFIG_PPC_ISERIES */ | |
1da177e4 | 495 | |
e360adbe | 496 | #ifdef CONFIG_IRQ_WORK |
105988c0 | 497 | |
0fe1ac48 PM |
498 | /* |
499 | * 64-bit uses a byte in the PACA, 32-bit uses a per-cpu variable... | |
500 | */ | |
501 | #ifdef CONFIG_PPC64 | |
e360adbe | 502 | static inline unsigned long test_irq_work_pending(void) |
105988c0 | 503 | { |
0fe1ac48 PM |
504 | unsigned long x; |
505 | ||
506 | asm volatile("lbz %0,%1(13)" | |
507 | : "=r" (x) | |
e360adbe | 508 | : "i" (offsetof(struct paca_struct, irq_work_pending))); |
0fe1ac48 PM |
509 | return x; |
510 | } | |
511 | ||
e360adbe | 512 | static inline void set_irq_work_pending_flag(void) |
0fe1ac48 PM |
513 | { |
514 | asm volatile("stb %0,%1(13)" : : | |
515 | "r" (1), | |
e360adbe | 516 | "i" (offsetof(struct paca_struct, irq_work_pending))); |
0fe1ac48 PM |
517 | } |
518 | ||
e360adbe | 519 | static inline void clear_irq_work_pending(void) |
0fe1ac48 PM |
520 | { |
521 | asm volatile("stb %0,%1(13)" : : | |
522 | "r" (0), | |
e360adbe | 523 | "i" (offsetof(struct paca_struct, irq_work_pending))); |
105988c0 PM |
524 | } |
525 | ||
0fe1ac48 PM |
526 | #else /* 32-bit */ |
527 | ||
e360adbe | 528 | DEFINE_PER_CPU(u8, irq_work_pending); |
0fe1ac48 | 529 | |
e360adbe PZ |
530 | #define set_irq_work_pending_flag() __get_cpu_var(irq_work_pending) = 1 |
531 | #define test_irq_work_pending() __get_cpu_var(irq_work_pending) | |
532 | #define clear_irq_work_pending() __get_cpu_var(irq_work_pending) = 0 | |
105988c0 | 533 | |
0fe1ac48 PM |
534 | #endif /* 32 vs 64 bit */ |
535 | ||
e360adbe | 536 | void set_irq_work_pending(void) |
0fe1ac48 PM |
537 | { |
538 | preempt_disable(); | |
e360adbe | 539 | set_irq_work_pending_flag(); |
0fe1ac48 PM |
540 | set_dec(1); |
541 | preempt_enable(); | |
542 | } | |
543 | ||
e360adbe | 544 | #else /* CONFIG_IRQ_WORK */ |
105988c0 | 545 | |
e360adbe PZ |
546 | #define test_irq_work_pending() 0 |
547 | #define clear_irq_work_pending() | |
105988c0 | 548 | |
e360adbe | 549 | #endif /* CONFIG_IRQ_WORK */ |
105988c0 | 550 | |
1da177e4 LT |
551 | /* |
552 | * For iSeries shared processors, we have to let the hypervisor | |
553 | * set the hardware decrementer. We set a virtual decrementer | |
554 | * in the lppaca and call the hypervisor if the virtual | |
555 | * decrementer is less than the current value in the hardware | |
556 | * decrementer. (almost always the new decrementer value will | |
557 | * be greater than the current hardware decementer so the hypervisor | |
558 | * call will not be needed) | |
559 | */ | |
560 | ||
1da177e4 LT |
561 | /* |
562 | * timer_interrupt - gets called when the decrementer overflows, | |
563 | * with interrupts disabled. | |
564 | */ | |
c7aeffc4 | 565 | void timer_interrupt(struct pt_regs * regs) |
1da177e4 | 566 | { |
7d12e780 | 567 | struct pt_regs *old_regs; |
6e6b44e8 MM |
568 | struct decrementer_clock *decrementer = &__get_cpu_var(decrementers); |
569 | struct clock_event_device *evt = &decrementer->event; | |
d968014b | 570 | u64 now; |
d831d0b8 | 571 | |
6795b85c AB |
572 | trace_timer_interrupt_entry(regs); |
573 | ||
89713ed1 AB |
574 | __get_cpu_var(irq_stat).timer_irqs++; |
575 | ||
d831d0b8 TB |
576 | /* Ensure a positive value is written to the decrementer, or else |
577 | * some CPUs will continuue to take decrementer exceptions */ | |
578 | set_dec(DECREMENTER_MAX); | |
f2783c15 | 579 | |
b0d278b7 | 580 | #if defined(CONFIG_PPC32) && defined(CONFIG_PMAC) |
f2783c15 PM |
581 | if (atomic_read(&ppc_n_lost_interrupts) != 0) |
582 | do_IRQ(regs); | |
583 | #endif | |
1da177e4 | 584 | |
7d12e780 | 585 | old_regs = set_irq_regs(regs); |
1da177e4 LT |
586 | irq_enter(); |
587 | ||
c6622f63 | 588 | calculate_steal_time(); |
1da177e4 | 589 | |
e360adbe PZ |
590 | if (test_irq_work_pending()) { |
591 | clear_irq_work_pending(); | |
592 | irq_work_run(); | |
0fe1ac48 PM |
593 | } |
594 | ||
f2783c15 | 595 | #ifdef CONFIG_PPC_ISERIES |
501b6d29 SR |
596 | if (firmware_has_feature(FW_FEATURE_ISERIES)) |
597 | get_lppaca()->int_dword.fields.decr_int = 0; | |
f2783c15 PM |
598 | #endif |
599 | ||
b0d278b7 PM |
600 | now = get_tb_or_rtc(); |
601 | if (now >= decrementer->next_tb) { | |
602 | decrementer->next_tb = ~(u64)0; | |
603 | if (evt->event_handler) | |
604 | evt->event_handler(evt); | |
605 | } else { | |
606 | now = decrementer->next_tb - now; | |
607 | if (now <= DECREMENTER_MAX) | |
608 | set_dec((int)now); | |
609 | } | |
1da177e4 LT |
610 | |
611 | #ifdef CONFIG_PPC_ISERIES | |
501b6d29 | 612 | if (firmware_has_feature(FW_FEATURE_ISERIES) && hvlpevent_is_pending()) |
35a84c2f | 613 | process_hvlpevents(); |
1da177e4 LT |
614 | #endif |
615 | ||
f2783c15 | 616 | #ifdef CONFIG_PPC64 |
8d15a3e5 | 617 | /* collect purr register values often, for accurate calculations */ |
1ababe11 | 618 | if (firmware_has_feature(FW_FEATURE_SPLPAR)) { |
1da177e4 LT |
619 | struct cpu_usage *cu = &__get_cpu_var(cpu_usage_array); |
620 | cu->current_tb = mfspr(SPRN_PURR); | |
621 | } | |
f2783c15 | 622 | #endif |
1da177e4 LT |
623 | |
624 | irq_exit(); | |
7d12e780 | 625 | set_irq_regs(old_regs); |
6795b85c AB |
626 | |
627 | trace_timer_interrupt_exit(regs); | |
1da177e4 LT |
628 | } |
629 | ||
7ac5dde9 | 630 | #ifdef CONFIG_SUSPEND |
d75d68cf | 631 | static void generic_suspend_disable_irqs(void) |
7ac5dde9 | 632 | { |
7ac5dde9 SW |
633 | /* Disable the decrementer, so that it doesn't interfere |
634 | * with suspending. | |
635 | */ | |
636 | ||
637 | set_dec(0x7fffffff); | |
638 | local_irq_disable(); | |
639 | set_dec(0x7fffffff); | |
640 | } | |
641 | ||
d75d68cf | 642 | static void generic_suspend_enable_irqs(void) |
7ac5dde9 | 643 | { |
7ac5dde9 | 644 | local_irq_enable(); |
7ac5dde9 SW |
645 | } |
646 | ||
647 | /* Overrides the weak version in kernel/power/main.c */ | |
648 | void arch_suspend_disable_irqs(void) | |
649 | { | |
650 | if (ppc_md.suspend_disable_irqs) | |
651 | ppc_md.suspend_disable_irqs(); | |
652 | generic_suspend_disable_irqs(); | |
653 | } | |
654 | ||
655 | /* Overrides the weak version in kernel/power/main.c */ | |
656 | void arch_suspend_enable_irqs(void) | |
657 | { | |
658 | generic_suspend_enable_irqs(); | |
659 | if (ppc_md.suspend_enable_irqs) | |
660 | ppc_md.suspend_enable_irqs(); | |
661 | } | |
662 | #endif | |
663 | ||
1da177e4 LT |
664 | /* |
665 | * Scheduler clock - returns current time in nanosec units. | |
666 | * | |
667 | * Note: mulhdu(a, b) (multiply high double unsigned) returns | |
668 | * the high 64 bits of a * b, i.e. (a * b) >> 64, where a and b | |
669 | * are 64-bit unsigned numbers. | |
670 | */ | |
671 | unsigned long long sched_clock(void) | |
672 | { | |
96c44507 PM |
673 | if (__USE_RTC()) |
674 | return get_rtc(); | |
fc9069fe | 675 | return mulhdu(get_tb() - boot_tb, tb_to_ns_scale) << tb_to_ns_shift; |
1da177e4 LT |
676 | } |
677 | ||
0bb474a4 | 678 | static int __init get_freq(char *name, int cells, unsigned long *val) |
10f7e7c1 AB |
679 | { |
680 | struct device_node *cpu; | |
a7f67bdf | 681 | const unsigned int *fp; |
0bb474a4 | 682 | int found = 0; |
10f7e7c1 | 683 | |
0bb474a4 | 684 | /* The cpu node should have timebase and clock frequency properties */ |
10f7e7c1 AB |
685 | cpu = of_find_node_by_type(NULL, "cpu"); |
686 | ||
d8a8188d | 687 | if (cpu) { |
e2eb6392 | 688 | fp = of_get_property(cpu, name, NULL); |
d8a8188d | 689 | if (fp) { |
0bb474a4 | 690 | found = 1; |
a4dc7ff0 | 691 | *val = of_read_ulong(fp, cells); |
10f7e7c1 | 692 | } |
0bb474a4 AB |
693 | |
694 | of_node_put(cpu); | |
10f7e7c1 | 695 | } |
0bb474a4 AB |
696 | |
697 | return found; | |
698 | } | |
699 | ||
77c0a700 BH |
700 | /* should become __cpuinit when secondary_cpu_time_init also is */ |
701 | void start_cpu_decrementer(void) | |
702 | { | |
703 | #if defined(CONFIG_BOOKE) || defined(CONFIG_40x) | |
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 /* defined(CONFIG_BOOKE) || defined(CONFIG_40x) */ | |
710 | } | |
711 | ||
0bb474a4 AB |
712 | void __init generic_calibrate_decr(void) |
713 | { | |
714 | ppc_tb_freq = DEFAULT_TB_FREQ; /* hardcoded default */ | |
715 | ||
716 | if (!get_freq("ibm,extended-timebase-frequency", 2, &ppc_tb_freq) && | |
717 | !get_freq("timebase-frequency", 1, &ppc_tb_freq)) { | |
718 | ||
10f7e7c1 AB |
719 | printk(KERN_ERR "WARNING: Estimating decrementer frequency " |
720 | "(not found)\n"); | |
0bb474a4 | 721 | } |
10f7e7c1 | 722 | |
0bb474a4 AB |
723 | ppc_proc_freq = DEFAULT_PROC_FREQ; /* hardcoded default */ |
724 | ||
725 | if (!get_freq("ibm,extended-clock-frequency", 2, &ppc_proc_freq) && | |
726 | !get_freq("clock-frequency", 1, &ppc_proc_freq)) { | |
727 | ||
728 | printk(KERN_ERR "WARNING: Estimating processor frequency " | |
729 | "(not found)\n"); | |
10f7e7c1 | 730 | } |
10f7e7c1 | 731 | } |
10f7e7c1 | 732 | |
aa3be5f3 | 733 | int update_persistent_clock(struct timespec now) |
f2783c15 PM |
734 | { |
735 | struct rtc_time tm; | |
736 | ||
aa3be5f3 TB |
737 | if (!ppc_md.set_rtc_time) |
738 | return 0; | |
739 | ||
740 | to_tm(now.tv_sec + 1 + timezone_offset, &tm); | |
741 | tm.tm_year -= 1900; | |
742 | tm.tm_mon -= 1; | |
743 | ||
744 | return ppc_md.set_rtc_time(&tm); | |
745 | } | |
746 | ||
978d7eb3 | 747 | static void __read_persistent_clock(struct timespec *ts) |
aa3be5f3 TB |
748 | { |
749 | struct rtc_time tm; | |
750 | static int first = 1; | |
751 | ||
d90246cd | 752 | ts->tv_nsec = 0; |
aa3be5f3 TB |
753 | /* XXX this is a litle fragile but will work okay in the short term */ |
754 | if (first) { | |
755 | first = 0; | |
756 | if (ppc_md.time_init) | |
757 | timezone_offset = ppc_md.time_init(); | |
758 | ||
759 | /* get_boot_time() isn't guaranteed to be safe to call late */ | |
d90246cd MS |
760 | if (ppc_md.get_boot_time) { |
761 | ts->tv_sec = ppc_md.get_boot_time() - timezone_offset; | |
762 | return; | |
763 | } | |
764 | } | |
765 | if (!ppc_md.get_rtc_time) { | |
766 | ts->tv_sec = 0; | |
767 | return; | |
aa3be5f3 | 768 | } |
f2783c15 | 769 | ppc_md.get_rtc_time(&tm); |
978d7eb3 | 770 | |
d4f587c6 MS |
771 | ts->tv_sec = mktime(tm.tm_year+1900, tm.tm_mon+1, tm.tm_mday, |
772 | tm.tm_hour, tm.tm_min, tm.tm_sec); | |
f2783c15 PM |
773 | } |
774 | ||
978d7eb3 BH |
775 | void read_persistent_clock(struct timespec *ts) |
776 | { | |
777 | __read_persistent_clock(ts); | |
778 | ||
779 | /* Sanitize it in case real time clock is set below EPOCH */ | |
780 | if (ts->tv_sec < 0) { | |
781 | ts->tv_sec = 0; | |
782 | ts->tv_nsec = 0; | |
783 | } | |
784 | ||
785 | } | |
786 | ||
4a4cfe38 | 787 | /* clocksource code */ |
8e19608e | 788 | static cycle_t rtc_read(struct clocksource *cs) |
4a4cfe38 TB |
789 | { |
790 | return (cycle_t)get_rtc(); | |
791 | } | |
792 | ||
8e19608e | 793 | static cycle_t timebase_read(struct clocksource *cs) |
4a4cfe38 TB |
794 | { |
795 | return (cycle_t)get_tb(); | |
796 | } | |
797 | ||
7615856e JS |
798 | void update_vsyscall(struct timespec *wall_time, struct timespec *wtm, |
799 | struct clocksource *clock, u32 mult) | |
4a4cfe38 | 800 | { |
b0797b60 | 801 | u64 new_tb_to_xs, new_stamp_xsec; |
47916be4 | 802 | u32 frac_sec; |
4a4cfe38 TB |
803 | |
804 | if (clock != &clocksource_timebase) | |
805 | return; | |
806 | ||
807 | /* Make userspace gettimeofday spin until we're done. */ | |
808 | ++vdso_data->tb_update_count; | |
809 | smp_mb(); | |
810 | ||
811 | /* XXX this assumes clock->shift == 22 */ | |
812 | /* 4611686018 ~= 2^(20+64-22) / 1e9 */ | |
b0797b60 | 813 | new_tb_to_xs = (u64) mult * 4611686018ULL; |
06d518e3 | 814 | new_stamp_xsec = (u64) wall_time->tv_nsec * XSEC_PER_SEC; |
b0797b60 | 815 | do_div(new_stamp_xsec, 1000000000); |
06d518e3 | 816 | new_stamp_xsec += (u64) wall_time->tv_sec * XSEC_PER_SEC; |
b0797b60 | 817 | |
47916be4 TG |
818 | BUG_ON(wall_time->tv_nsec >= NSEC_PER_SEC); |
819 | /* this is tv_nsec / 1e9 as a 0.32 fraction */ | |
820 | frac_sec = ((u64) wall_time->tv_nsec * 18446744073ULL) >> 32; | |
821 | ||
b0797b60 JS |
822 | /* |
823 | * tb_update_count is used to allow the userspace gettimeofday code | |
824 | * to assure itself that it sees a consistent view of the tb_to_xs and | |
825 | * stamp_xsec variables. It reads the tb_update_count, then reads | |
826 | * tb_to_xs and stamp_xsec and then reads tb_update_count again. If | |
827 | * the two values of tb_update_count match and are even then the | |
828 | * tb_to_xs and stamp_xsec values are consistent. If not, then it | |
829 | * loops back and reads them again until this criteria is met. | |
830 | * We expect the caller to have done the first increment of | |
831 | * vdso_data->tb_update_count already. | |
832 | */ | |
833 | vdso_data->tb_orig_stamp = clock->cycle_last; | |
834 | vdso_data->stamp_xsec = new_stamp_xsec; | |
835 | vdso_data->tb_to_xs = new_tb_to_xs; | |
7615856e JS |
836 | vdso_data->wtom_clock_sec = wtm->tv_sec; |
837 | vdso_data->wtom_clock_nsec = wtm->tv_nsec; | |
06d518e3 | 838 | vdso_data->stamp_xtime = *wall_time; |
0e469db8 | 839 | vdso_data->stamp_sec_fraction = frac_sec; |
b0797b60 JS |
840 | smp_wmb(); |
841 | ++(vdso_data->tb_update_count); | |
4a4cfe38 TB |
842 | } |
843 | ||
844 | void update_vsyscall_tz(void) | |
845 | { | |
846 | /* Make userspace gettimeofday spin until we're done. */ | |
847 | ++vdso_data->tb_update_count; | |
848 | smp_mb(); | |
849 | vdso_data->tz_minuteswest = sys_tz.tz_minuteswest; | |
850 | vdso_data->tz_dsttime = sys_tz.tz_dsttime; | |
851 | smp_mb(); | |
852 | ++vdso_data->tb_update_count; | |
853 | } | |
854 | ||
1c21a293 | 855 | static void __init clocksource_init(void) |
4a4cfe38 TB |
856 | { |
857 | struct clocksource *clock; | |
858 | ||
859 | if (__USE_RTC()) | |
860 | clock = &clocksource_rtc; | |
861 | else | |
862 | clock = &clocksource_timebase; | |
863 | ||
864 | clock->mult = clocksource_hz2mult(tb_ticks_per_sec, clock->shift); | |
865 | ||
866 | if (clocksource_register(clock)) { | |
867 | printk(KERN_ERR "clocksource: %s is already registered\n", | |
868 | clock->name); | |
869 | return; | |
870 | } | |
871 | ||
872 | printk(KERN_INFO "clocksource: %s mult[%x] shift[%d] registered\n", | |
873 | clock->name, clock->mult, clock->shift); | |
874 | } | |
875 | ||
d831d0b8 TB |
876 | static int decrementer_set_next_event(unsigned long evt, |
877 | struct clock_event_device *dev) | |
878 | { | |
6e6b44e8 | 879 | __get_cpu_var(decrementers).next_tb = get_tb_or_rtc() + evt; |
d831d0b8 TB |
880 | set_dec(evt); |
881 | return 0; | |
882 | } | |
883 | ||
884 | static void decrementer_set_mode(enum clock_event_mode mode, | |
885 | struct clock_event_device *dev) | |
886 | { | |
887 | if (mode != CLOCK_EVT_MODE_ONESHOT) | |
888 | decrementer_set_next_event(DECREMENTER_MAX, dev); | |
889 | } | |
890 | ||
3e7b4843 SR |
891 | static inline uint64_t div_sc64(unsigned long ticks, unsigned long nsec, |
892 | int shift) | |
893 | { | |
894 | uint64_t tmp = ((uint64_t)ticks) << shift; | |
895 | ||
896 | do_div(tmp, nsec); | |
897 | return tmp; | |
898 | } | |
899 | ||
8d165db1 AB |
900 | static void __init setup_clockevent_multiplier(unsigned long hz) |
901 | { | |
902 | u64 mult, shift = 32; | |
903 | ||
904 | while (1) { | |
3e7b4843 | 905 | mult = div_sc64(hz, NSEC_PER_SEC, shift); |
8d165db1 AB |
906 | if (mult && (mult >> 32UL) == 0UL) |
907 | break; | |
908 | ||
909 | shift--; | |
910 | } | |
911 | ||
912 | decrementer_clockevent.shift = shift; | |
913 | decrementer_clockevent.mult = mult; | |
914 | } | |
915 | ||
d831d0b8 TB |
916 | static void register_decrementer_clockevent(int cpu) |
917 | { | |
6e6b44e8 | 918 | struct clock_event_device *dec = &per_cpu(decrementers, cpu).event; |
d831d0b8 TB |
919 | |
920 | *dec = decrementer_clockevent; | |
320ab2b0 | 921 | dec->cpumask = cpumask_of(cpu); |
d831d0b8 | 922 | |
b919ee82 AB |
923 | printk_once(KERN_DEBUG "clockevent: %s mult[%x] shift[%d] cpu[%d]\n", |
924 | dec->name, dec->mult, dec->shift, cpu); | |
d831d0b8 TB |
925 | |
926 | clockevents_register_device(dec); | |
927 | } | |
928 | ||
c481887f | 929 | static void __init init_decrementer_clockevent(void) |
d831d0b8 TB |
930 | { |
931 | int cpu = smp_processor_id(); | |
932 | ||
8d165db1 | 933 | setup_clockevent_multiplier(ppc_tb_freq); |
d831d0b8 TB |
934 | decrementer_clockevent.max_delta_ns = |
935 | clockevent_delta2ns(DECREMENTER_MAX, &decrementer_clockevent); | |
43875cc0 PM |
936 | decrementer_clockevent.min_delta_ns = |
937 | clockevent_delta2ns(2, &decrementer_clockevent); | |
d831d0b8 TB |
938 | |
939 | register_decrementer_clockevent(cpu); | |
940 | } | |
941 | ||
942 | void secondary_cpu_time_init(void) | |
943 | { | |
77c0a700 BH |
944 | /* Start the decrementer on CPUs that have manual control |
945 | * such as BookE | |
946 | */ | |
947 | start_cpu_decrementer(); | |
948 | ||
d831d0b8 TB |
949 | /* FIME: Should make unrelatred change to move snapshot_timebase |
950 | * call here ! */ | |
951 | register_decrementer_clockevent(smp_processor_id()); | |
952 | } | |
953 | ||
f2783c15 | 954 | /* This function is only called on the boot processor */ |
1da177e4 LT |
955 | void __init time_init(void) |
956 | { | |
1da177e4 | 957 | struct div_result res; |
d75d68cf | 958 | u64 scale; |
f2783c15 PM |
959 | unsigned shift; |
960 | ||
96c44507 PM |
961 | if (__USE_RTC()) { |
962 | /* 601 processor: dec counts down by 128 every 128ns */ | |
963 | ppc_tb_freq = 1000000000; | |
96c44507 PM |
964 | } else { |
965 | /* Normal PowerPC with timebase register */ | |
966 | ppc_md.calibrate_decr(); | |
224ad80a | 967 | printk(KERN_DEBUG "time_init: decrementer frequency = %lu.%.6lu MHz\n", |
96c44507 | 968 | ppc_tb_freq / 1000000, ppc_tb_freq % 1000000); |
224ad80a | 969 | printk(KERN_DEBUG "time_init: processor frequency = %lu.%.6lu MHz\n", |
96c44507 | 970 | ppc_proc_freq / 1000000, ppc_proc_freq % 1000000); |
96c44507 | 971 | } |
374e99d4 PM |
972 | |
973 | tb_ticks_per_jiffy = ppc_tb_freq / HZ; | |
092b8f34 | 974 | tb_ticks_per_sec = ppc_tb_freq; |
374e99d4 | 975 | tb_ticks_per_usec = ppc_tb_freq / 1000000; |
c6622f63 | 976 | calc_cputime_factors(); |
a42548a1 | 977 | setup_cputime_one_jiffy(); |
092b8f34 | 978 | |
1da177e4 LT |
979 | /* |
980 | * Compute scale factor for sched_clock. | |
981 | * The calibrate_decr() function has set tb_ticks_per_sec, | |
982 | * which is the timebase frequency. | |
983 | * We compute 1e9 * 2^64 / tb_ticks_per_sec and interpret | |
984 | * the 128-bit result as a 64.64 fixed-point number. | |
985 | * We then shift that number right until it is less than 1.0, | |
986 | * giving us the scale factor and shift count to use in | |
987 | * sched_clock(). | |
988 | */ | |
989 | div128_by_32(1000000000, 0, tb_ticks_per_sec, &res); | |
990 | scale = res.result_low; | |
991 | for (shift = 0; res.result_high != 0; ++shift) { | |
992 | scale = (scale >> 1) | (res.result_high << 63); | |
993 | res.result_high >>= 1; | |
994 | } | |
995 | tb_to_ns_scale = scale; | |
996 | tb_to_ns_shift = shift; | |
fc9069fe | 997 | /* Save the current timebase to pretty up CONFIG_PRINTK_TIME */ |
c27da339 | 998 | boot_tb = get_tb_or_rtc(); |
1da177e4 | 999 | |
092b8f34 PM |
1000 | /* If platform provided a timezone (pmac), we correct the time */ |
1001 | if (timezone_offset) { | |
1002 | sys_tz.tz_minuteswest = -timezone_offset / 60; | |
1003 | sys_tz.tz_dsttime = 0; | |
092b8f34 PM |
1004 | } |
1005 | ||
a7f290da BH |
1006 | vdso_data->tb_update_count = 0; |
1007 | vdso_data->tb_ticks_per_sec = tb_ticks_per_sec; | |
1da177e4 | 1008 | |
77c0a700 BH |
1009 | /* Start the decrementer on CPUs that have manual control |
1010 | * such as BookE | |
1011 | */ | |
1012 | start_cpu_decrementer(); | |
1013 | ||
4a4cfe38 TB |
1014 | /* Register the clocksource, if we're not running on iSeries */ |
1015 | if (!firmware_has_feature(FW_FEATURE_ISERIES)) | |
1016 | clocksource_init(); | |
1017 | ||
d831d0b8 | 1018 | init_decrementer_clockevent(); |
1da177e4 LT |
1019 | } |
1020 | ||
1da177e4 | 1021 | |
1da177e4 LT |
1022 | #define FEBRUARY 2 |
1023 | #define STARTOFTIME 1970 | |
1024 | #define SECDAY 86400L | |
1025 | #define SECYR (SECDAY * 365) | |
f2783c15 PM |
1026 | #define leapyear(year) ((year) % 4 == 0 && \ |
1027 | ((year) % 100 != 0 || (year) % 400 == 0)) | |
1da177e4 LT |
1028 | #define days_in_year(a) (leapyear(a) ? 366 : 365) |
1029 | #define days_in_month(a) (month_days[(a) - 1]) | |
1030 | ||
1031 | static int month_days[12] = { | |
1032 | 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 | |
1033 | }; | |
1034 | ||
1035 | /* | |
1036 | * This only works for the Gregorian calendar - i.e. after 1752 (in the UK) | |
1037 | */ | |
1038 | void GregorianDay(struct rtc_time * tm) | |
1039 | { | |
1040 | int leapsToDate; | |
1041 | int lastYear; | |
1042 | int day; | |
1043 | int MonthOffset[] = { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 }; | |
1044 | ||
f2783c15 | 1045 | lastYear = tm->tm_year - 1; |
1da177e4 LT |
1046 | |
1047 | /* | |
1048 | * Number of leap corrections to apply up to end of last year | |
1049 | */ | |
f2783c15 | 1050 | leapsToDate = lastYear / 4 - lastYear / 100 + lastYear / 400; |
1da177e4 LT |
1051 | |
1052 | /* | |
1053 | * This year is a leap year if it is divisible by 4 except when it is | |
1054 | * divisible by 100 unless it is divisible by 400 | |
1055 | * | |
f2783c15 | 1056 | * e.g. 1904 was a leap year, 1900 was not, 1996 is, and 2000 was |
1da177e4 | 1057 | */ |
f2783c15 | 1058 | day = tm->tm_mon > 2 && leapyear(tm->tm_year); |
1da177e4 LT |
1059 | |
1060 | day += lastYear*365 + leapsToDate + MonthOffset[tm->tm_mon-1] + | |
1061 | tm->tm_mday; | |
1062 | ||
f2783c15 | 1063 | tm->tm_wday = day % 7; |
1da177e4 LT |
1064 | } |
1065 | ||
1066 | void to_tm(int tim, struct rtc_time * tm) | |
1067 | { | |
1068 | register int i; | |
1069 | register long hms, day; | |
1070 | ||
1071 | day = tim / SECDAY; | |
1072 | hms = tim % SECDAY; | |
1073 | ||
1074 | /* Hours, minutes, seconds are easy */ | |
1075 | tm->tm_hour = hms / 3600; | |
1076 | tm->tm_min = (hms % 3600) / 60; | |
1077 | tm->tm_sec = (hms % 3600) % 60; | |
1078 | ||
1079 | /* Number of years in days */ | |
1080 | for (i = STARTOFTIME; day >= days_in_year(i); i++) | |
1081 | day -= days_in_year(i); | |
1082 | tm->tm_year = i; | |
1083 | ||
1084 | /* Number of months in days left */ | |
1085 | if (leapyear(tm->tm_year)) | |
1086 | days_in_month(FEBRUARY) = 29; | |
1087 | for (i = 1; day >= days_in_month(i); i++) | |
1088 | day -= days_in_month(i); | |
1089 | days_in_month(FEBRUARY) = 28; | |
1090 | tm->tm_mon = i; | |
1091 | ||
1092 | /* Days are what is left over (+1) from all that. */ | |
1093 | tm->tm_mday = day + 1; | |
1094 | ||
1095 | /* | |
1096 | * Determine the day of week | |
1097 | */ | |
1098 | GregorianDay(tm); | |
1099 | } | |
1100 | ||
1da177e4 LT |
1101 | /* |
1102 | * Divide a 128-bit dividend by a 32-bit divisor, leaving a 128 bit | |
1103 | * result. | |
1104 | */ | |
f2783c15 PM |
1105 | void div128_by_32(u64 dividend_high, u64 dividend_low, |
1106 | unsigned divisor, struct div_result *dr) | |
1da177e4 | 1107 | { |
f2783c15 PM |
1108 | unsigned long a, b, c, d; |
1109 | unsigned long w, x, y, z; | |
1110 | u64 ra, rb, rc; | |
1da177e4 LT |
1111 | |
1112 | a = dividend_high >> 32; | |
1113 | b = dividend_high & 0xffffffff; | |
1114 | c = dividend_low >> 32; | |
1115 | d = dividend_low & 0xffffffff; | |
1116 | ||
f2783c15 PM |
1117 | w = a / divisor; |
1118 | ra = ((u64)(a - (w * divisor)) << 32) + b; | |
1119 | ||
f2783c15 PM |
1120 | rb = ((u64) do_div(ra, divisor) << 32) + c; |
1121 | x = ra; | |
1da177e4 | 1122 | |
f2783c15 PM |
1123 | rc = ((u64) do_div(rb, divisor) << 32) + d; |
1124 | y = rb; | |
1125 | ||
1126 | do_div(rc, divisor); | |
1127 | z = rc; | |
1da177e4 | 1128 | |
f2783c15 PM |
1129 | dr->result_high = ((u64)w << 32) + x; |
1130 | dr->result_low = ((u64)y << 32) + z; | |
1da177e4 LT |
1131 | |
1132 | } | |
bcd68a70 | 1133 | |
177996e6 BH |
1134 | /* We don't need to calibrate delay, we use the CPU timebase for that */ |
1135 | void calibrate_delay(void) | |
1136 | { | |
1137 | /* Some generic code (such as spinlock debug) use loops_per_jiffy | |
1138 | * as the number of __delay(1) in a jiffy, so make it so | |
1139 | */ | |
1140 | loops_per_jiffy = tb_ticks_per_jiffy; | |
1141 | } | |
1142 | ||
bcd68a70 GU |
1143 | static int __init rtc_init(void) |
1144 | { | |
1145 | struct platform_device *pdev; | |
1146 | ||
1147 | if (!ppc_md.get_rtc_time) | |
1148 | return -ENODEV; | |
1149 | ||
1150 | pdev = platform_device_register_simple("rtc-generic", -1, NULL, 0); | |
1151 | if (IS_ERR(pdev)) | |
1152 | return PTR_ERR(pdev); | |
1153 | ||
1154 | return 0; | |
1155 | } | |
1156 | ||
1157 | module_init(rtc_init); |