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 | 35 | #include <linux/errno.h> |
4b16f8e2 | 36 | #include <linux/export.h> |
1da177e4 LT |
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, | |
d831d0b8 TB |
115 | .irq = 0, |
116 | .set_next_event = decrementer_set_next_event, | |
117 | .set_mode = decrementer_set_mode, | |
118 | .features = CLOCK_EVT_FEAT_ONESHOT, | |
119 | }; | |
120 | ||
6e6b44e8 MM |
121 | struct decrementer_clock { |
122 | struct clock_event_device event; | |
123 | u64 next_tb; | |
124 | }; | |
125 | ||
126 | static DEFINE_PER_CPU(struct decrementer_clock, decrementers); | |
d831d0b8 | 127 | |
1da177e4 | 128 | #ifdef CONFIG_PPC_ISERIES |
71712b45 TB |
129 | static unsigned long __initdata iSeries_recal_titan; |
130 | static signed long __initdata iSeries_recal_tb; | |
4a4cfe38 TB |
131 | |
132 | /* Forward declaration is only needed for iSereis compiles */ | |
1c21a293 | 133 | static void __init clocksource_init(void); |
1da177e4 LT |
134 | #endif |
135 | ||
136 | #define XSEC_PER_SEC (1024*1024) | |
137 | ||
f2783c15 PM |
138 | #ifdef CONFIG_PPC64 |
139 | #define SCALE_XSEC(xsec, max) (((xsec) * max) / XSEC_PER_SEC) | |
140 | #else | |
141 | /* compute ((xsec << 12) * max) >> 32 */ | |
142 | #define SCALE_XSEC(xsec, max) mulhwu((xsec) << 12, max) | |
143 | #endif | |
144 | ||
1da177e4 LT |
145 | unsigned long tb_ticks_per_jiffy; |
146 | unsigned long tb_ticks_per_usec = 100; /* sane default */ | |
147 | EXPORT_SYMBOL(tb_ticks_per_usec); | |
148 | unsigned long tb_ticks_per_sec; | |
2cf82c02 | 149 | EXPORT_SYMBOL(tb_ticks_per_sec); /* for cputime_t conversions */ |
092b8f34 | 150 | |
1da177e4 | 151 | DEFINE_SPINLOCK(rtc_lock); |
6ae3db11 | 152 | EXPORT_SYMBOL_GPL(rtc_lock); |
1da177e4 | 153 | |
fc9069fe TB |
154 | static u64 tb_to_ns_scale __read_mostly; |
155 | static unsigned tb_to_ns_shift __read_mostly; | |
364a1246 | 156 | static u64 boot_tb __read_mostly; |
1da177e4 | 157 | |
1da177e4 | 158 | extern struct timezone sys_tz; |
f2783c15 | 159 | static long timezone_offset; |
1da177e4 | 160 | |
10f7e7c1 | 161 | unsigned long ppc_proc_freq; |
55ec2fca | 162 | EXPORT_SYMBOL_GPL(ppc_proc_freq); |
10f7e7c1 | 163 | unsigned long ppc_tb_freq; |
55ec2fca | 164 | EXPORT_SYMBOL_GPL(ppc_tb_freq); |
96c44507 | 165 | |
c6622f63 PM |
166 | #ifdef CONFIG_VIRT_CPU_ACCOUNTING |
167 | /* | |
168 | * Factors for converting from cputime_t (timebase ticks) to | |
169 | * jiffies, milliseconds, seconds, and clock_t (1/USER_HZ seconds). | |
170 | * These are all stored as 0.64 fixed-point binary fractions. | |
171 | */ | |
172 | u64 __cputime_jiffies_factor; | |
2cf82c02 | 173 | EXPORT_SYMBOL(__cputime_jiffies_factor); |
c6622f63 | 174 | u64 __cputime_msec_factor; |
2cf82c02 | 175 | EXPORT_SYMBOL(__cputime_msec_factor); |
c6622f63 | 176 | u64 __cputime_sec_factor; |
2cf82c02 | 177 | EXPORT_SYMBOL(__cputime_sec_factor); |
c6622f63 | 178 | u64 __cputime_clockt_factor; |
2cf82c02 | 179 | EXPORT_SYMBOL(__cputime_clockt_factor); |
06b8e878 MN |
180 | DEFINE_PER_CPU(unsigned long, cputime_last_delta); |
181 | DEFINE_PER_CPU(unsigned long, cputime_scaled_last_delta); | |
c6622f63 | 182 | |
a42548a1 SG |
183 | cputime_t cputime_one_jiffy; |
184 | ||
872e439a PM |
185 | void (*dtl_consumer)(struct dtl_entry *, u64); |
186 | ||
c6622f63 PM |
187 | static void calc_cputime_factors(void) |
188 | { | |
189 | struct div_result res; | |
190 | ||
191 | div128_by_32(HZ, 0, tb_ticks_per_sec, &res); | |
192 | __cputime_jiffies_factor = res.result_low; | |
193 | div128_by_32(1000, 0, tb_ticks_per_sec, &res); | |
194 | __cputime_msec_factor = res.result_low; | |
195 | div128_by_32(1, 0, tb_ticks_per_sec, &res); | |
196 | __cputime_sec_factor = res.result_low; | |
197 | div128_by_32(USER_HZ, 0, tb_ticks_per_sec, &res); | |
198 | __cputime_clockt_factor = res.result_low; | |
199 | } | |
200 | ||
201 | /* | |
cf9efce0 PM |
202 | * Read the SPURR on systems that have it, otherwise the PURR, |
203 | * or if that doesn't exist return the timebase value passed in. | |
c6622f63 | 204 | */ |
cf9efce0 | 205 | static u64 read_spurr(u64 tb) |
c6622f63 | 206 | { |
cf9efce0 PM |
207 | if (cpu_has_feature(CPU_FTR_SPURR)) |
208 | return mfspr(SPRN_SPURR); | |
c6622f63 PM |
209 | if (cpu_has_feature(CPU_FTR_PURR)) |
210 | return mfspr(SPRN_PURR); | |
cf9efce0 | 211 | return tb; |
c6622f63 PM |
212 | } |
213 | ||
cf9efce0 PM |
214 | #ifdef CONFIG_PPC_SPLPAR |
215 | ||
4603ac18 | 216 | /* |
cf9efce0 PM |
217 | * Scan the dispatch trace log and count up the stolen time. |
218 | * Should be called with interrupts disabled. | |
4603ac18 | 219 | */ |
cf9efce0 | 220 | static u64 scan_dispatch_log(u64 stop_tb) |
4603ac18 | 221 | { |
872e439a | 222 | u64 i = local_paca->dtl_ridx; |
cf9efce0 PM |
223 | struct dtl_entry *dtl = local_paca->dtl_curr; |
224 | struct dtl_entry *dtl_end = local_paca->dispatch_log_end; | |
225 | struct lppaca *vpa = local_paca->lppaca_ptr; | |
226 | u64 tb_delta; | |
227 | u64 stolen = 0; | |
228 | u64 dtb; | |
229 | ||
84ffae55 AB |
230 | if (!dtl) |
231 | return 0; | |
232 | ||
cf9efce0 PM |
233 | if (i == vpa->dtl_idx) |
234 | return 0; | |
235 | while (i < vpa->dtl_idx) { | |
872e439a PM |
236 | if (dtl_consumer) |
237 | dtl_consumer(dtl, i); | |
cf9efce0 PM |
238 | dtb = dtl->timebase; |
239 | tb_delta = dtl->enqueue_to_dispatch_time + | |
240 | dtl->ready_to_enqueue_time; | |
241 | barrier(); | |
242 | if (i + N_DISPATCH_LOG < vpa->dtl_idx) { | |
243 | /* buffer has overflowed */ | |
244 | i = vpa->dtl_idx - N_DISPATCH_LOG; | |
245 | dtl = local_paca->dispatch_log + (i % N_DISPATCH_LOG); | |
246 | continue; | |
247 | } | |
248 | if (dtb > stop_tb) | |
249 | break; | |
250 | stolen += tb_delta; | |
251 | ++i; | |
252 | ++dtl; | |
253 | if (dtl == dtl_end) | |
254 | dtl = local_paca->dispatch_log; | |
255 | } | |
256 | local_paca->dtl_ridx = i; | |
257 | local_paca->dtl_curr = dtl; | |
258 | return stolen; | |
4603ac18 MN |
259 | } |
260 | ||
cf9efce0 PM |
261 | /* |
262 | * Accumulate stolen time by scanning the dispatch trace log. | |
263 | * Called on entry from user mode. | |
264 | */ | |
265 | void accumulate_stolen_time(void) | |
266 | { | |
267 | u64 sst, ust; | |
268 | ||
b18ae08d TH |
269 | u8 save_soft_enabled = local_paca->soft_enabled; |
270 | u8 save_hard_enabled = local_paca->hard_enabled; | |
271 | ||
272 | /* We are called early in the exception entry, before | |
273 | * soft/hard_enabled are sync'ed to the expected state | |
274 | * for the exception. We are hard disabled but the PACA | |
275 | * needs to reflect that so various debug stuff doesn't | |
276 | * complain | |
277 | */ | |
278 | local_paca->soft_enabled = 0; | |
279 | local_paca->hard_enabled = 0; | |
280 | ||
281 | sst = scan_dispatch_log(local_paca->starttime_user); | |
282 | ust = scan_dispatch_log(local_paca->starttime); | |
283 | local_paca->system_time -= sst; | |
284 | local_paca->user_time -= ust; | |
285 | local_paca->stolen_time += ust + sst; | |
286 | ||
287 | local_paca->soft_enabled = save_soft_enabled; | |
288 | local_paca->hard_enabled = save_hard_enabled; | |
cf9efce0 PM |
289 | } |
290 | ||
291 | static inline u64 calculate_stolen_time(u64 stop_tb) | |
292 | { | |
293 | u64 stolen = 0; | |
294 | ||
295 | if (get_paca()->dtl_ridx != get_paca()->lppaca_ptr->dtl_idx) { | |
296 | stolen = scan_dispatch_log(stop_tb); | |
297 | get_paca()->system_time -= stolen; | |
298 | } | |
299 | ||
300 | stolen += get_paca()->stolen_time; | |
301 | get_paca()->stolen_time = 0; | |
302 | return stolen; | |
4603ac18 MN |
303 | } |
304 | ||
cf9efce0 PM |
305 | #else /* CONFIG_PPC_SPLPAR */ |
306 | static inline u64 calculate_stolen_time(u64 stop_tb) | |
307 | { | |
308 | return 0; | |
309 | } | |
310 | ||
311 | #endif /* CONFIG_PPC_SPLPAR */ | |
312 | ||
c6622f63 PM |
313 | /* |
314 | * Account time for a transition between system, hard irq | |
315 | * or soft irq state. | |
316 | */ | |
317 | void account_system_vtime(struct task_struct *tsk) | |
318 | { | |
cf9efce0 | 319 | u64 now, nowscaled, delta, deltascaled; |
c6622f63 | 320 | unsigned long flags; |
cf9efce0 | 321 | u64 stolen, udelta, sys_scaled, user_scaled; |
c6622f63 PM |
322 | |
323 | local_irq_save(flags); | |
cf9efce0 | 324 | now = mftb(); |
4603ac18 | 325 | nowscaled = read_spurr(now); |
cf9efce0 PM |
326 | get_paca()->system_time += now - get_paca()->starttime; |
327 | get_paca()->starttime = now; | |
4603ac18 MN |
328 | deltascaled = nowscaled - get_paca()->startspurr; |
329 | get_paca()->startspurr = nowscaled; | |
cf9efce0 PM |
330 | |
331 | stolen = calculate_stolen_time(now); | |
332 | ||
333 | delta = get_paca()->system_time; | |
334 | get_paca()->system_time = 0; | |
335 | udelta = get_paca()->user_time - get_paca()->utime_sspurr; | |
336 | get_paca()->utime_sspurr = get_paca()->user_time; | |
337 | ||
338 | /* | |
339 | * Because we don't read the SPURR on every kernel entry/exit, | |
340 | * deltascaled includes both user and system SPURR ticks. | |
341 | * Apportion these ticks to system SPURR ticks and user | |
342 | * SPURR ticks in the same ratio as the system time (delta) | |
343 | * and user time (udelta) values obtained from the timebase | |
344 | * over the same interval. The system ticks get accounted here; | |
345 | * the user ticks get saved up in paca->user_time_scaled to be | |
346 | * used by account_process_tick. | |
347 | */ | |
348 | sys_scaled = delta; | |
349 | user_scaled = udelta; | |
350 | if (deltascaled != delta + udelta) { | |
351 | if (udelta) { | |
352 | sys_scaled = deltascaled * delta / (delta + udelta); | |
353 | user_scaled = deltascaled - sys_scaled; | |
354 | } else { | |
355 | sys_scaled = deltascaled; | |
356 | } | |
357 | } | |
358 | get_paca()->user_time_scaled += user_scaled; | |
359 | ||
ad5d1c88 | 360 | if (in_interrupt() || idle_task(smp_processor_id()) != tsk) { |
cf9efce0 PM |
361 | account_system_time(tsk, 0, delta, sys_scaled); |
362 | if (stolen) | |
363 | account_steal_time(stolen); | |
364 | } else { | |
365 | account_idle_time(delta + stolen); | |
c6622f63 | 366 | } |
c6622f63 PM |
367 | local_irq_restore(flags); |
368 | } | |
4ab79aa8 | 369 | EXPORT_SYMBOL_GPL(account_system_vtime); |
c6622f63 PM |
370 | |
371 | /* | |
372 | * Transfer the user and system times accumulated in the paca | |
373 | * by the exception entry and exit code to the generic process | |
374 | * user and system time records. | |
375 | * Must be called with interrupts disabled. | |
cf9efce0 PM |
376 | * Assumes that account_system_vtime() has been called recently |
377 | * (i.e. since the last entry from usermode) so that | |
378 | * get_paca()->user_time_scaled is up to date. | |
c6622f63 | 379 | */ |
fa13a5a1 | 380 | void account_process_tick(struct task_struct *tsk, int user_tick) |
c6622f63 | 381 | { |
4603ac18 | 382 | cputime_t utime, utimescaled; |
c6622f63 PM |
383 | |
384 | utime = get_paca()->user_time; | |
cf9efce0 | 385 | utimescaled = get_paca()->user_time_scaled; |
c6622f63 | 386 | get_paca()->user_time = 0; |
cf9efce0 PM |
387 | get_paca()->user_time_scaled = 0; |
388 | get_paca()->utime_sspurr = 0; | |
457533a7 | 389 | account_user_time(tsk, utime, utimescaled); |
c6622f63 PM |
390 | } |
391 | ||
c6622f63 PM |
392 | #else /* ! CONFIG_VIRT_CPU_ACCOUNTING */ |
393 | #define calc_cputime_factors() | |
c6622f63 PM |
394 | #endif |
395 | ||
6defa38b PM |
396 | void __delay(unsigned long loops) |
397 | { | |
398 | unsigned long start; | |
399 | int diff; | |
400 | ||
401 | if (__USE_RTC()) { | |
402 | start = get_rtcl(); | |
403 | do { | |
404 | /* the RTCL register wraps at 1000000000 */ | |
405 | diff = get_rtcl() - start; | |
406 | if (diff < 0) | |
407 | diff += 1000000000; | |
408 | } while (diff < loops); | |
409 | } else { | |
410 | start = get_tbl(); | |
411 | while (get_tbl() - start < loops) | |
412 | HMT_low(); | |
413 | HMT_medium(); | |
414 | } | |
415 | } | |
416 | EXPORT_SYMBOL(__delay); | |
417 | ||
418 | void udelay(unsigned long usecs) | |
419 | { | |
420 | __delay(tb_ticks_per_usec * usecs); | |
421 | } | |
422 | EXPORT_SYMBOL(udelay); | |
423 | ||
1da177e4 LT |
424 | #ifdef CONFIG_SMP |
425 | unsigned long profile_pc(struct pt_regs *regs) | |
426 | { | |
427 | unsigned long pc = instruction_pointer(regs); | |
428 | ||
429 | if (in_lock_functions(pc)) | |
430 | return regs->link; | |
431 | ||
432 | return pc; | |
433 | } | |
434 | EXPORT_SYMBOL(profile_pc); | |
435 | #endif | |
436 | ||
437 | #ifdef CONFIG_PPC_ISERIES | |
438 | ||
439 | /* | |
440 | * This function recalibrates the timebase based on the 49-bit time-of-day | |
441 | * value in the Titan chip. The Titan is much more accurate than the value | |
442 | * returned by the service processor for the timebase frequency. | |
443 | */ | |
444 | ||
71712b45 | 445 | static int __init iSeries_tb_recal(void) |
1da177e4 | 446 | { |
1da177e4 | 447 | unsigned long titan, tb; |
71712b45 TB |
448 | |
449 | /* Make sure we only run on iSeries */ | |
450 | if (!firmware_has_feature(FW_FEATURE_ISERIES)) | |
451 | return -ENODEV; | |
452 | ||
1da177e4 LT |
453 | tb = get_tb(); |
454 | titan = HvCallXm_loadTod(); | |
455 | if ( iSeries_recal_titan ) { | |
456 | unsigned long tb_ticks = tb - iSeries_recal_tb; | |
457 | unsigned long titan_usec = (titan - iSeries_recal_titan) >> 12; | |
458 | unsigned long new_tb_ticks_per_sec = (tb_ticks * USEC_PER_SEC)/titan_usec; | |
14ea58ad JL |
459 | unsigned long new_tb_ticks_per_jiffy = |
460 | DIV_ROUND_CLOSEST(new_tb_ticks_per_sec, HZ); | |
1da177e4 LT |
461 | long tick_diff = new_tb_ticks_per_jiffy - tb_ticks_per_jiffy; |
462 | char sign = '+'; | |
463 | /* make sure tb_ticks_per_sec and tb_ticks_per_jiffy are consistent */ | |
464 | new_tb_ticks_per_sec = new_tb_ticks_per_jiffy * HZ; | |
465 | ||
466 | if ( tick_diff < 0 ) { | |
467 | tick_diff = -tick_diff; | |
468 | sign = '-'; | |
469 | } | |
470 | if ( tick_diff ) { | |
471 | if ( tick_diff < tb_ticks_per_jiffy/25 ) { | |
472 | printk( "Titan recalibrate: new tb_ticks_per_jiffy = %lu (%c%ld)\n", | |
473 | new_tb_ticks_per_jiffy, sign, tick_diff ); | |
474 | tb_ticks_per_jiffy = new_tb_ticks_per_jiffy; | |
475 | tb_ticks_per_sec = new_tb_ticks_per_sec; | |
c6622f63 | 476 | calc_cputime_factors(); |
a7f290da | 477 | vdso_data->tb_ticks_per_sec = tb_ticks_per_sec; |
a42548a1 | 478 | setup_cputime_one_jiffy(); |
1da177e4 LT |
479 | } |
480 | else { | |
481 | printk( "Titan recalibrate: FAILED (difference > 4 percent)\n" | |
482 | " new tb_ticks_per_jiffy = %lu\n" | |
483 | " old tb_ticks_per_jiffy = %lu\n", | |
484 | new_tb_ticks_per_jiffy, tb_ticks_per_jiffy ); | |
485 | } | |
486 | } | |
487 | } | |
488 | iSeries_recal_titan = titan; | |
489 | iSeries_recal_tb = tb; | |
71712b45 | 490 | |
4a4cfe38 TB |
491 | /* Called here as now we know accurate values for the timebase */ |
492 | clocksource_init(); | |
71712b45 | 493 | return 0; |
1da177e4 | 494 | } |
71712b45 TB |
495 | late_initcall(iSeries_tb_recal); |
496 | ||
497 | /* Called from platform early init */ | |
498 | void __init iSeries_time_init_early(void) | |
499 | { | |
500 | iSeries_recal_tb = get_tb(); | |
501 | iSeries_recal_titan = HvCallXm_loadTod(); | |
502 | } | |
503 | #endif /* CONFIG_PPC_ISERIES */ | |
1da177e4 | 504 | |
e360adbe | 505 | #ifdef CONFIG_IRQ_WORK |
105988c0 | 506 | |
0fe1ac48 PM |
507 | /* |
508 | * 64-bit uses a byte in the PACA, 32-bit uses a per-cpu variable... | |
509 | */ | |
510 | #ifdef CONFIG_PPC64 | |
e360adbe | 511 | static inline unsigned long test_irq_work_pending(void) |
105988c0 | 512 | { |
0fe1ac48 PM |
513 | unsigned long x; |
514 | ||
515 | asm volatile("lbz %0,%1(13)" | |
516 | : "=r" (x) | |
e360adbe | 517 | : "i" (offsetof(struct paca_struct, irq_work_pending))); |
0fe1ac48 PM |
518 | return x; |
519 | } | |
520 | ||
e360adbe | 521 | static inline void set_irq_work_pending_flag(void) |
0fe1ac48 PM |
522 | { |
523 | asm volatile("stb %0,%1(13)" : : | |
524 | "r" (1), | |
e360adbe | 525 | "i" (offsetof(struct paca_struct, irq_work_pending))); |
0fe1ac48 PM |
526 | } |
527 | ||
e360adbe | 528 | static inline void clear_irq_work_pending(void) |
0fe1ac48 PM |
529 | { |
530 | asm volatile("stb %0,%1(13)" : : | |
531 | "r" (0), | |
e360adbe | 532 | "i" (offsetof(struct paca_struct, irq_work_pending))); |
105988c0 PM |
533 | } |
534 | ||
0fe1ac48 PM |
535 | #else /* 32-bit */ |
536 | ||
e360adbe | 537 | DEFINE_PER_CPU(u8, irq_work_pending); |
0fe1ac48 | 538 | |
e360adbe PZ |
539 | #define set_irq_work_pending_flag() __get_cpu_var(irq_work_pending) = 1 |
540 | #define test_irq_work_pending() __get_cpu_var(irq_work_pending) | |
541 | #define clear_irq_work_pending() __get_cpu_var(irq_work_pending) = 0 | |
105988c0 | 542 | |
0fe1ac48 PM |
543 | #endif /* 32 vs 64 bit */ |
544 | ||
4f8b50bb | 545 | void arch_irq_work_raise(void) |
0fe1ac48 PM |
546 | { |
547 | preempt_disable(); | |
e360adbe | 548 | set_irq_work_pending_flag(); |
0fe1ac48 PM |
549 | set_dec(1); |
550 | preempt_enable(); | |
551 | } | |
552 | ||
e360adbe | 553 | #else /* CONFIG_IRQ_WORK */ |
105988c0 | 554 | |
e360adbe PZ |
555 | #define test_irq_work_pending() 0 |
556 | #define clear_irq_work_pending() | |
105988c0 | 557 | |
e360adbe | 558 | #endif /* CONFIG_IRQ_WORK */ |
105988c0 | 559 | |
1da177e4 LT |
560 | /* |
561 | * For iSeries shared processors, we have to let the hypervisor | |
562 | * set the hardware decrementer. We set a virtual decrementer | |
563 | * in the lppaca and call the hypervisor if the virtual | |
564 | * decrementer is less than the current value in the hardware | |
565 | * decrementer. (almost always the new decrementer value will | |
566 | * be greater than the current hardware decementer so the hypervisor | |
567 | * call will not be needed) | |
568 | */ | |
569 | ||
1da177e4 LT |
570 | /* |
571 | * timer_interrupt - gets called when the decrementer overflows, | |
572 | * with interrupts disabled. | |
573 | */ | |
c7aeffc4 | 574 | void timer_interrupt(struct pt_regs * regs) |
1da177e4 | 575 | { |
7d12e780 | 576 | struct pt_regs *old_regs; |
6e6b44e8 MM |
577 | struct decrementer_clock *decrementer = &__get_cpu_var(decrementers); |
578 | struct clock_event_device *evt = &decrementer->event; | |
d968014b | 579 | u64 now; |
d831d0b8 | 580 | |
963e5d3b BH |
581 | /* Ensure a positive value is written to the decrementer, or else |
582 | * some CPUs will continue to take decrementer exceptions. | |
583 | */ | |
584 | set_dec(DECREMENTER_MAX); | |
585 | ||
586 | /* Some implementations of hotplug will get timer interrupts while | |
587 | * offline, just ignore these | |
588 | */ | |
589 | if (!cpu_online(smp_processor_id())) | |
590 | return; | |
591 | ||
6795b85c AB |
592 | trace_timer_interrupt_entry(regs); |
593 | ||
89713ed1 AB |
594 | __get_cpu_var(irq_stat).timer_irqs++; |
595 | ||
b0d278b7 | 596 | #if defined(CONFIG_PPC32) && defined(CONFIG_PMAC) |
f2783c15 PM |
597 | if (atomic_read(&ppc_n_lost_interrupts) != 0) |
598 | do_IRQ(regs); | |
599 | #endif | |
1da177e4 | 600 | |
7d12e780 | 601 | old_regs = set_irq_regs(regs); |
1da177e4 LT |
602 | irq_enter(); |
603 | ||
e360adbe PZ |
604 | if (test_irq_work_pending()) { |
605 | clear_irq_work_pending(); | |
606 | irq_work_run(); | |
0fe1ac48 PM |
607 | } |
608 | ||
f2783c15 | 609 | #ifdef CONFIG_PPC_ISERIES |
501b6d29 SR |
610 | if (firmware_has_feature(FW_FEATURE_ISERIES)) |
611 | get_lppaca()->int_dword.fields.decr_int = 0; | |
f2783c15 PM |
612 | #endif |
613 | ||
b0d278b7 PM |
614 | now = get_tb_or_rtc(); |
615 | if (now >= decrementer->next_tb) { | |
616 | decrementer->next_tb = ~(u64)0; | |
617 | if (evt->event_handler) | |
618 | evt->event_handler(evt); | |
619 | } else { | |
620 | now = decrementer->next_tb - now; | |
621 | if (now <= DECREMENTER_MAX) | |
622 | set_dec((int)now); | |
623 | } | |
1da177e4 LT |
624 | |
625 | #ifdef CONFIG_PPC_ISERIES | |
501b6d29 | 626 | if (firmware_has_feature(FW_FEATURE_ISERIES) && hvlpevent_is_pending()) |
35a84c2f | 627 | process_hvlpevents(); |
1da177e4 LT |
628 | #endif |
629 | ||
f2783c15 | 630 | #ifdef CONFIG_PPC64 |
8d15a3e5 | 631 | /* collect purr register values often, for accurate calculations */ |
1ababe11 | 632 | if (firmware_has_feature(FW_FEATURE_SPLPAR)) { |
1da177e4 LT |
633 | struct cpu_usage *cu = &__get_cpu_var(cpu_usage_array); |
634 | cu->current_tb = mfspr(SPRN_PURR); | |
635 | } | |
f2783c15 | 636 | #endif |
1da177e4 LT |
637 | |
638 | irq_exit(); | |
7d12e780 | 639 | set_irq_regs(old_regs); |
6795b85c AB |
640 | |
641 | trace_timer_interrupt_exit(regs); | |
1da177e4 LT |
642 | } |
643 | ||
7ac5dde9 | 644 | #ifdef CONFIG_SUSPEND |
d75d68cf | 645 | static void generic_suspend_disable_irqs(void) |
7ac5dde9 | 646 | { |
7ac5dde9 SW |
647 | /* Disable the decrementer, so that it doesn't interfere |
648 | * with suspending. | |
649 | */ | |
650 | ||
651 | set_dec(0x7fffffff); | |
652 | local_irq_disable(); | |
653 | set_dec(0x7fffffff); | |
654 | } | |
655 | ||
d75d68cf | 656 | static void generic_suspend_enable_irqs(void) |
7ac5dde9 | 657 | { |
7ac5dde9 | 658 | local_irq_enable(); |
7ac5dde9 SW |
659 | } |
660 | ||
661 | /* Overrides the weak version in kernel/power/main.c */ | |
662 | void arch_suspend_disable_irqs(void) | |
663 | { | |
664 | if (ppc_md.suspend_disable_irqs) | |
665 | ppc_md.suspend_disable_irqs(); | |
666 | generic_suspend_disable_irqs(); | |
667 | } | |
668 | ||
669 | /* Overrides the weak version in kernel/power/main.c */ | |
670 | void arch_suspend_enable_irqs(void) | |
671 | { | |
672 | generic_suspend_enable_irqs(); | |
673 | if (ppc_md.suspend_enable_irqs) | |
674 | ppc_md.suspend_enable_irqs(); | |
675 | } | |
676 | #endif | |
677 | ||
1da177e4 LT |
678 | /* |
679 | * Scheduler clock - returns current time in nanosec units. | |
680 | * | |
681 | * Note: mulhdu(a, b) (multiply high double unsigned) returns | |
682 | * the high 64 bits of a * b, i.e. (a * b) >> 64, where a and b | |
683 | * are 64-bit unsigned numbers. | |
684 | */ | |
685 | unsigned long long sched_clock(void) | |
686 | { | |
96c44507 PM |
687 | if (__USE_RTC()) |
688 | return get_rtc(); | |
fc9069fe | 689 | return mulhdu(get_tb() - boot_tb, tb_to_ns_scale) << tb_to_ns_shift; |
1da177e4 LT |
690 | } |
691 | ||
0bb474a4 | 692 | static int __init get_freq(char *name, int cells, unsigned long *val) |
10f7e7c1 AB |
693 | { |
694 | struct device_node *cpu; | |
a7f67bdf | 695 | const unsigned int *fp; |
0bb474a4 | 696 | int found = 0; |
10f7e7c1 | 697 | |
0bb474a4 | 698 | /* The cpu node should have timebase and clock frequency properties */ |
10f7e7c1 AB |
699 | cpu = of_find_node_by_type(NULL, "cpu"); |
700 | ||
d8a8188d | 701 | if (cpu) { |
e2eb6392 | 702 | fp = of_get_property(cpu, name, NULL); |
d8a8188d | 703 | if (fp) { |
0bb474a4 | 704 | found = 1; |
a4dc7ff0 | 705 | *val = of_read_ulong(fp, cells); |
10f7e7c1 | 706 | } |
0bb474a4 AB |
707 | |
708 | of_node_put(cpu); | |
10f7e7c1 | 709 | } |
0bb474a4 AB |
710 | |
711 | return found; | |
712 | } | |
713 | ||
77c0a700 BH |
714 | /* should become __cpuinit when secondary_cpu_time_init also is */ |
715 | void start_cpu_decrementer(void) | |
716 | { | |
717 | #if defined(CONFIG_BOOKE) || defined(CONFIG_40x) | |
718 | /* Clear any pending timer interrupts */ | |
719 | mtspr(SPRN_TSR, TSR_ENW | TSR_WIS | TSR_DIS | TSR_FIS); | |
720 | ||
721 | /* Enable decrementer interrupt */ | |
722 | mtspr(SPRN_TCR, TCR_DIE); | |
723 | #endif /* defined(CONFIG_BOOKE) || defined(CONFIG_40x) */ | |
724 | } | |
725 | ||
0bb474a4 AB |
726 | void __init generic_calibrate_decr(void) |
727 | { | |
728 | ppc_tb_freq = DEFAULT_TB_FREQ; /* hardcoded default */ | |
729 | ||
730 | if (!get_freq("ibm,extended-timebase-frequency", 2, &ppc_tb_freq) && | |
731 | !get_freq("timebase-frequency", 1, &ppc_tb_freq)) { | |
732 | ||
10f7e7c1 AB |
733 | printk(KERN_ERR "WARNING: Estimating decrementer frequency " |
734 | "(not found)\n"); | |
0bb474a4 | 735 | } |
10f7e7c1 | 736 | |
0bb474a4 AB |
737 | ppc_proc_freq = DEFAULT_PROC_FREQ; /* hardcoded default */ |
738 | ||
739 | if (!get_freq("ibm,extended-clock-frequency", 2, &ppc_proc_freq) && | |
740 | !get_freq("clock-frequency", 1, &ppc_proc_freq)) { | |
741 | ||
742 | printk(KERN_ERR "WARNING: Estimating processor frequency " | |
743 | "(not found)\n"); | |
10f7e7c1 | 744 | } |
10f7e7c1 | 745 | } |
10f7e7c1 | 746 | |
aa3be5f3 | 747 | int update_persistent_clock(struct timespec now) |
f2783c15 PM |
748 | { |
749 | struct rtc_time tm; | |
750 | ||
aa3be5f3 TB |
751 | if (!ppc_md.set_rtc_time) |
752 | return 0; | |
753 | ||
754 | to_tm(now.tv_sec + 1 + timezone_offset, &tm); | |
755 | tm.tm_year -= 1900; | |
756 | tm.tm_mon -= 1; | |
757 | ||
758 | return ppc_md.set_rtc_time(&tm); | |
759 | } | |
760 | ||
978d7eb3 | 761 | static void __read_persistent_clock(struct timespec *ts) |
aa3be5f3 TB |
762 | { |
763 | struct rtc_time tm; | |
764 | static int first = 1; | |
765 | ||
d90246cd | 766 | ts->tv_nsec = 0; |
aa3be5f3 TB |
767 | /* XXX this is a litle fragile but will work okay in the short term */ |
768 | if (first) { | |
769 | first = 0; | |
770 | if (ppc_md.time_init) | |
771 | timezone_offset = ppc_md.time_init(); | |
772 | ||
773 | /* get_boot_time() isn't guaranteed to be safe to call late */ | |
d90246cd MS |
774 | if (ppc_md.get_boot_time) { |
775 | ts->tv_sec = ppc_md.get_boot_time() - timezone_offset; | |
776 | return; | |
777 | } | |
778 | } | |
779 | if (!ppc_md.get_rtc_time) { | |
780 | ts->tv_sec = 0; | |
781 | return; | |
aa3be5f3 | 782 | } |
f2783c15 | 783 | ppc_md.get_rtc_time(&tm); |
978d7eb3 | 784 | |
d4f587c6 MS |
785 | ts->tv_sec = mktime(tm.tm_year+1900, tm.tm_mon+1, tm.tm_mday, |
786 | tm.tm_hour, tm.tm_min, tm.tm_sec); | |
f2783c15 PM |
787 | } |
788 | ||
978d7eb3 BH |
789 | void read_persistent_clock(struct timespec *ts) |
790 | { | |
791 | __read_persistent_clock(ts); | |
792 | ||
793 | /* Sanitize it in case real time clock is set below EPOCH */ | |
794 | if (ts->tv_sec < 0) { | |
795 | ts->tv_sec = 0; | |
796 | ts->tv_nsec = 0; | |
797 | } | |
798 | ||
799 | } | |
800 | ||
4a4cfe38 | 801 | /* clocksource code */ |
8e19608e | 802 | static cycle_t rtc_read(struct clocksource *cs) |
4a4cfe38 TB |
803 | { |
804 | return (cycle_t)get_rtc(); | |
805 | } | |
806 | ||
8e19608e | 807 | static cycle_t timebase_read(struct clocksource *cs) |
4a4cfe38 TB |
808 | { |
809 | return (cycle_t)get_tb(); | |
810 | } | |
811 | ||
7615856e JS |
812 | void update_vsyscall(struct timespec *wall_time, struct timespec *wtm, |
813 | struct clocksource *clock, u32 mult) | |
4a4cfe38 | 814 | { |
b0797b60 | 815 | u64 new_tb_to_xs, new_stamp_xsec; |
47916be4 | 816 | u32 frac_sec; |
4a4cfe38 TB |
817 | |
818 | if (clock != &clocksource_timebase) | |
819 | return; | |
820 | ||
821 | /* Make userspace gettimeofday spin until we're done. */ | |
822 | ++vdso_data->tb_update_count; | |
823 | smp_mb(); | |
824 | ||
825 | /* XXX this assumes clock->shift == 22 */ | |
826 | /* 4611686018 ~= 2^(20+64-22) / 1e9 */ | |
b0797b60 | 827 | new_tb_to_xs = (u64) mult * 4611686018ULL; |
06d518e3 | 828 | new_stamp_xsec = (u64) wall_time->tv_nsec * XSEC_PER_SEC; |
b0797b60 | 829 | do_div(new_stamp_xsec, 1000000000); |
06d518e3 | 830 | new_stamp_xsec += (u64) wall_time->tv_sec * XSEC_PER_SEC; |
b0797b60 | 831 | |
47916be4 TG |
832 | BUG_ON(wall_time->tv_nsec >= NSEC_PER_SEC); |
833 | /* this is tv_nsec / 1e9 as a 0.32 fraction */ | |
834 | frac_sec = ((u64) wall_time->tv_nsec * 18446744073ULL) >> 32; | |
835 | ||
b0797b60 JS |
836 | /* |
837 | * tb_update_count is used to allow the userspace gettimeofday code | |
838 | * to assure itself that it sees a consistent view of the tb_to_xs and | |
839 | * stamp_xsec variables. It reads the tb_update_count, then reads | |
840 | * tb_to_xs and stamp_xsec and then reads tb_update_count again. If | |
841 | * the two values of tb_update_count match and are even then the | |
842 | * tb_to_xs and stamp_xsec values are consistent. If not, then it | |
843 | * loops back and reads them again until this criteria is met. | |
844 | * We expect the caller to have done the first increment of | |
845 | * vdso_data->tb_update_count already. | |
846 | */ | |
847 | vdso_data->tb_orig_stamp = clock->cycle_last; | |
848 | vdso_data->stamp_xsec = new_stamp_xsec; | |
849 | vdso_data->tb_to_xs = new_tb_to_xs; | |
7615856e JS |
850 | vdso_data->wtom_clock_sec = wtm->tv_sec; |
851 | vdso_data->wtom_clock_nsec = wtm->tv_nsec; | |
06d518e3 | 852 | vdso_data->stamp_xtime = *wall_time; |
0e469db8 | 853 | vdso_data->stamp_sec_fraction = frac_sec; |
b0797b60 JS |
854 | smp_wmb(); |
855 | ++(vdso_data->tb_update_count); | |
4a4cfe38 TB |
856 | } |
857 | ||
858 | void update_vsyscall_tz(void) | |
859 | { | |
860 | /* Make userspace gettimeofday spin until we're done. */ | |
861 | ++vdso_data->tb_update_count; | |
862 | smp_mb(); | |
863 | vdso_data->tz_minuteswest = sys_tz.tz_minuteswest; | |
864 | vdso_data->tz_dsttime = sys_tz.tz_dsttime; | |
865 | smp_mb(); | |
866 | ++vdso_data->tb_update_count; | |
867 | } | |
868 | ||
1c21a293 | 869 | static void __init clocksource_init(void) |
4a4cfe38 TB |
870 | { |
871 | struct clocksource *clock; | |
872 | ||
873 | if (__USE_RTC()) | |
874 | clock = &clocksource_rtc; | |
875 | else | |
876 | clock = &clocksource_timebase; | |
877 | ||
878 | clock->mult = clocksource_hz2mult(tb_ticks_per_sec, clock->shift); | |
879 | ||
880 | if (clocksource_register(clock)) { | |
881 | printk(KERN_ERR "clocksource: %s is already registered\n", | |
882 | clock->name); | |
883 | return; | |
884 | } | |
885 | ||
886 | printk(KERN_INFO "clocksource: %s mult[%x] shift[%d] registered\n", | |
887 | clock->name, clock->mult, clock->shift); | |
888 | } | |
889 | ||
37fb9a02 AB |
890 | void decrementer_check_overflow(void) |
891 | { | |
892 | u64 now = get_tb_or_rtc(); | |
893 | struct decrementer_clock *decrementer = &__get_cpu_var(decrementers); | |
894 | ||
895 | if (now >= decrementer->next_tb) | |
896 | set_dec(1); | |
897 | } | |
898 | ||
d831d0b8 TB |
899 | static int decrementer_set_next_event(unsigned long evt, |
900 | struct clock_event_device *dev) | |
901 | { | |
6e6b44e8 | 902 | __get_cpu_var(decrementers).next_tb = get_tb_or_rtc() + evt; |
d831d0b8 TB |
903 | set_dec(evt); |
904 | return 0; | |
905 | } | |
906 | ||
907 | static void decrementer_set_mode(enum clock_event_mode mode, | |
908 | struct clock_event_device *dev) | |
909 | { | |
910 | if (mode != CLOCK_EVT_MODE_ONESHOT) | |
911 | decrementer_set_next_event(DECREMENTER_MAX, dev); | |
912 | } | |
913 | ||
914 | static void register_decrementer_clockevent(int cpu) | |
915 | { | |
6e6b44e8 | 916 | struct clock_event_device *dec = &per_cpu(decrementers, cpu).event; |
d831d0b8 TB |
917 | |
918 | *dec = decrementer_clockevent; | |
320ab2b0 | 919 | dec->cpumask = cpumask_of(cpu); |
d831d0b8 | 920 | |
b919ee82 AB |
921 | printk_once(KERN_DEBUG "clockevent: %s mult[%x] shift[%d] cpu[%d]\n", |
922 | dec->name, dec->mult, dec->shift, cpu); | |
d831d0b8 TB |
923 | |
924 | clockevents_register_device(dec); | |
925 | } | |
926 | ||
c481887f | 927 | static void __init init_decrementer_clockevent(void) |
d831d0b8 TB |
928 | { |
929 | int cpu = smp_processor_id(); | |
930 | ||
d8afc6fd AB |
931 | clockevents_calc_mult_shift(&decrementer_clockevent, ppc_tb_freq, 4); |
932 | ||
d831d0b8 TB |
933 | decrementer_clockevent.max_delta_ns = |
934 | clockevent_delta2ns(DECREMENTER_MAX, &decrementer_clockevent); | |
43875cc0 PM |
935 | decrementer_clockevent.min_delta_ns = |
936 | clockevent_delta2ns(2, &decrementer_clockevent); | |
d831d0b8 TB |
937 | |
938 | register_decrementer_clockevent(cpu); | |
939 | } | |
940 | ||
941 | void secondary_cpu_time_init(void) | |
942 | { | |
77c0a700 BH |
943 | /* Start the decrementer on CPUs that have manual control |
944 | * such as BookE | |
945 | */ | |
946 | start_cpu_decrementer(); | |
947 | ||
d831d0b8 TB |
948 | /* FIME: Should make unrelatred change to move snapshot_timebase |
949 | * call here ! */ | |
950 | register_decrementer_clockevent(smp_processor_id()); | |
951 | } | |
952 | ||
f2783c15 | 953 | /* This function is only called on the boot processor */ |
1da177e4 LT |
954 | void __init time_init(void) |
955 | { | |
1da177e4 | 956 | struct div_result res; |
d75d68cf | 957 | u64 scale; |
f2783c15 PM |
958 | unsigned shift; |
959 | ||
96c44507 PM |
960 | if (__USE_RTC()) { |
961 | /* 601 processor: dec counts down by 128 every 128ns */ | |
962 | ppc_tb_freq = 1000000000; | |
96c44507 PM |
963 | } else { |
964 | /* Normal PowerPC with timebase register */ | |
965 | ppc_md.calibrate_decr(); | |
224ad80a | 966 | printk(KERN_DEBUG "time_init: decrementer frequency = %lu.%.6lu MHz\n", |
96c44507 | 967 | ppc_tb_freq / 1000000, ppc_tb_freq % 1000000); |
224ad80a | 968 | printk(KERN_DEBUG "time_init: processor frequency = %lu.%.6lu MHz\n", |
96c44507 | 969 | ppc_proc_freq / 1000000, ppc_proc_freq % 1000000); |
96c44507 | 970 | } |
374e99d4 PM |
971 | |
972 | tb_ticks_per_jiffy = ppc_tb_freq / HZ; | |
092b8f34 | 973 | tb_ticks_per_sec = ppc_tb_freq; |
374e99d4 | 974 | tb_ticks_per_usec = ppc_tb_freq / 1000000; |
c6622f63 | 975 | calc_cputime_factors(); |
a42548a1 | 976 | setup_cputime_one_jiffy(); |
092b8f34 | 977 | |
1da177e4 LT |
978 | /* |
979 | * Compute scale factor for sched_clock. | |
980 | * The calibrate_decr() function has set tb_ticks_per_sec, | |
981 | * which is the timebase frequency. | |
982 | * We compute 1e9 * 2^64 / tb_ticks_per_sec and interpret | |
983 | * the 128-bit result as a 64.64 fixed-point number. | |
984 | * We then shift that number right until it is less than 1.0, | |
985 | * giving us the scale factor and shift count to use in | |
986 | * sched_clock(). | |
987 | */ | |
988 | div128_by_32(1000000000, 0, tb_ticks_per_sec, &res); | |
989 | scale = res.result_low; | |
990 | for (shift = 0; res.result_high != 0; ++shift) { | |
991 | scale = (scale >> 1) | (res.result_high << 63); | |
992 | res.result_high >>= 1; | |
993 | } | |
994 | tb_to_ns_scale = scale; | |
995 | tb_to_ns_shift = shift; | |
fc9069fe | 996 | /* Save the current timebase to pretty up CONFIG_PRINTK_TIME */ |
c27da339 | 997 | boot_tb = get_tb_or_rtc(); |
1da177e4 | 998 | |
092b8f34 PM |
999 | /* If platform provided a timezone (pmac), we correct the time */ |
1000 | if (timezone_offset) { | |
1001 | sys_tz.tz_minuteswest = -timezone_offset / 60; | |
1002 | sys_tz.tz_dsttime = 0; | |
092b8f34 PM |
1003 | } |
1004 | ||
a7f290da BH |
1005 | vdso_data->tb_update_count = 0; |
1006 | vdso_data->tb_ticks_per_sec = tb_ticks_per_sec; | |
1da177e4 | 1007 | |
77c0a700 BH |
1008 | /* Start the decrementer on CPUs that have manual control |
1009 | * such as BookE | |
1010 | */ | |
1011 | start_cpu_decrementer(); | |
1012 | ||
4a4cfe38 TB |
1013 | /* Register the clocksource, if we're not running on iSeries */ |
1014 | if (!firmware_has_feature(FW_FEATURE_ISERIES)) | |
1015 | clocksource_init(); | |
1016 | ||
d831d0b8 | 1017 | init_decrementer_clockevent(); |
1da177e4 LT |
1018 | } |
1019 | ||
1da177e4 | 1020 | |
1da177e4 LT |
1021 | #define FEBRUARY 2 |
1022 | #define STARTOFTIME 1970 | |
1023 | #define SECDAY 86400L | |
1024 | #define SECYR (SECDAY * 365) | |
f2783c15 PM |
1025 | #define leapyear(year) ((year) % 4 == 0 && \ |
1026 | ((year) % 100 != 0 || (year) % 400 == 0)) | |
1da177e4 LT |
1027 | #define days_in_year(a) (leapyear(a) ? 366 : 365) |
1028 | #define days_in_month(a) (month_days[(a) - 1]) | |
1029 | ||
1030 | static int month_days[12] = { | |
1031 | 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 | |
1032 | }; | |
1033 | ||
1034 | /* | |
1035 | * This only works for the Gregorian calendar - i.e. after 1752 (in the UK) | |
1036 | */ | |
1037 | void GregorianDay(struct rtc_time * tm) | |
1038 | { | |
1039 | int leapsToDate; | |
1040 | int lastYear; | |
1041 | int day; | |
1042 | int MonthOffset[] = { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 }; | |
1043 | ||
f2783c15 | 1044 | lastYear = tm->tm_year - 1; |
1da177e4 LT |
1045 | |
1046 | /* | |
1047 | * Number of leap corrections to apply up to end of last year | |
1048 | */ | |
f2783c15 | 1049 | leapsToDate = lastYear / 4 - lastYear / 100 + lastYear / 400; |
1da177e4 LT |
1050 | |
1051 | /* | |
1052 | * This year is a leap year if it is divisible by 4 except when it is | |
1053 | * divisible by 100 unless it is divisible by 400 | |
1054 | * | |
f2783c15 | 1055 | * e.g. 1904 was a leap year, 1900 was not, 1996 is, and 2000 was |
1da177e4 | 1056 | */ |
f2783c15 | 1057 | day = tm->tm_mon > 2 && leapyear(tm->tm_year); |
1da177e4 LT |
1058 | |
1059 | day += lastYear*365 + leapsToDate + MonthOffset[tm->tm_mon-1] + | |
1060 | tm->tm_mday; | |
1061 | ||
f2783c15 | 1062 | tm->tm_wday = day % 7; |
1da177e4 LT |
1063 | } |
1064 | ||
1065 | void to_tm(int tim, struct rtc_time * tm) | |
1066 | { | |
1067 | register int i; | |
1068 | register long hms, day; | |
1069 | ||
1070 | day = tim / SECDAY; | |
1071 | hms = tim % SECDAY; | |
1072 | ||
1073 | /* Hours, minutes, seconds are easy */ | |
1074 | tm->tm_hour = hms / 3600; | |
1075 | tm->tm_min = (hms % 3600) / 60; | |
1076 | tm->tm_sec = (hms % 3600) % 60; | |
1077 | ||
1078 | /* Number of years in days */ | |
1079 | for (i = STARTOFTIME; day >= days_in_year(i); i++) | |
1080 | day -= days_in_year(i); | |
1081 | tm->tm_year = i; | |
1082 | ||
1083 | /* Number of months in days left */ | |
1084 | if (leapyear(tm->tm_year)) | |
1085 | days_in_month(FEBRUARY) = 29; | |
1086 | for (i = 1; day >= days_in_month(i); i++) | |
1087 | day -= days_in_month(i); | |
1088 | days_in_month(FEBRUARY) = 28; | |
1089 | tm->tm_mon = i; | |
1090 | ||
1091 | /* Days are what is left over (+1) from all that. */ | |
1092 | tm->tm_mday = day + 1; | |
1093 | ||
1094 | /* | |
1095 | * Determine the day of week | |
1096 | */ | |
1097 | GregorianDay(tm); | |
1098 | } | |
1099 | ||
1da177e4 LT |
1100 | /* |
1101 | * Divide a 128-bit dividend by a 32-bit divisor, leaving a 128 bit | |
1102 | * result. | |
1103 | */ | |
f2783c15 PM |
1104 | void div128_by_32(u64 dividend_high, u64 dividend_low, |
1105 | unsigned divisor, struct div_result *dr) | |
1da177e4 | 1106 | { |
f2783c15 PM |
1107 | unsigned long a, b, c, d; |
1108 | unsigned long w, x, y, z; | |
1109 | u64 ra, rb, rc; | |
1da177e4 LT |
1110 | |
1111 | a = dividend_high >> 32; | |
1112 | b = dividend_high & 0xffffffff; | |
1113 | c = dividend_low >> 32; | |
1114 | d = dividend_low & 0xffffffff; | |
1115 | ||
f2783c15 PM |
1116 | w = a / divisor; |
1117 | ra = ((u64)(a - (w * divisor)) << 32) + b; | |
1118 | ||
f2783c15 PM |
1119 | rb = ((u64) do_div(ra, divisor) << 32) + c; |
1120 | x = ra; | |
1da177e4 | 1121 | |
f2783c15 PM |
1122 | rc = ((u64) do_div(rb, divisor) << 32) + d; |
1123 | y = rb; | |
1124 | ||
1125 | do_div(rc, divisor); | |
1126 | z = rc; | |
1da177e4 | 1127 | |
f2783c15 PM |
1128 | dr->result_high = ((u64)w << 32) + x; |
1129 | dr->result_low = ((u64)y << 32) + z; | |
1da177e4 LT |
1130 | |
1131 | } | |
bcd68a70 | 1132 | |
177996e6 BH |
1133 | /* We don't need to calibrate delay, we use the CPU timebase for that */ |
1134 | void calibrate_delay(void) | |
1135 | { | |
1136 | /* Some generic code (such as spinlock debug) use loops_per_jiffy | |
1137 | * as the number of __delay(1) in a jiffy, so make it so | |
1138 | */ | |
1139 | loops_per_jiffy = tb_ticks_per_jiffy; | |
1140 | } | |
1141 | ||
bcd68a70 GU |
1142 | static int __init rtc_init(void) |
1143 | { | |
1144 | struct platform_device *pdev; | |
1145 | ||
1146 | if (!ppc_md.get_rtc_time) | |
1147 | return -ENODEV; | |
1148 | ||
1149 | pdev = platform_device_register_simple("rtc-generic", -1, NULL, 0); | |
1150 | if (IS_ERR(pdev)) | |
1151 | return PTR_ERR(pdev); | |
1152 | ||
1153 | return 0; | |
1154 | } | |
1155 | ||
1156 | module_init(rtc_init); |