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> |
105988c0 | 56 | #include <linux/perf_counter.h> |
1da177e4 | 57 | |
1da177e4 LT |
58 | #include <asm/io.h> |
59 | #include <asm/processor.h> | |
60 | #include <asm/nvram.h> | |
61 | #include <asm/cache.h> | |
62 | #include <asm/machdep.h> | |
1da177e4 LT |
63 | #include <asm/uaccess.h> |
64 | #include <asm/time.h> | |
1da177e4 | 65 | #include <asm/prom.h> |
f2783c15 PM |
66 | #include <asm/irq.h> |
67 | #include <asm/div64.h> | |
2249ca9d | 68 | #include <asm/smp.h> |
a7f290da | 69 | #include <asm/vdso_datapage.h> |
1ababe11 | 70 | #include <asm/firmware.h> |
06b8e878 | 71 | #include <asm/cputime.h> |
f2783c15 | 72 | #ifdef CONFIG_PPC_ISERIES |
8875ccfb | 73 | #include <asm/iseries/it_lp_queue.h> |
8021b8a7 | 74 | #include <asm/iseries/hv_call_xm.h> |
f2783c15 | 75 | #endif |
1da177e4 | 76 | |
4a4cfe38 TB |
77 | /* powerpc clocksource/clockevent code */ |
78 | ||
d831d0b8 | 79 | #include <linux/clockchips.h> |
4a4cfe38 TB |
80 | #include <linux/clocksource.h> |
81 | ||
8e19608e | 82 | static cycle_t rtc_read(struct clocksource *); |
4a4cfe38 TB |
83 | static struct clocksource clocksource_rtc = { |
84 | .name = "rtc", | |
85 | .rating = 400, | |
86 | .flags = CLOCK_SOURCE_IS_CONTINUOUS, | |
87 | .mask = CLOCKSOURCE_MASK(64), | |
88 | .shift = 22, | |
89 | .mult = 0, /* To be filled in */ | |
90 | .read = rtc_read, | |
91 | }; | |
92 | ||
8e19608e | 93 | static cycle_t timebase_read(struct clocksource *); |
4a4cfe38 TB |
94 | static struct clocksource clocksource_timebase = { |
95 | .name = "timebase", | |
96 | .rating = 400, | |
97 | .flags = CLOCK_SOURCE_IS_CONTINUOUS, | |
98 | .mask = CLOCKSOURCE_MASK(64), | |
99 | .shift = 22, | |
100 | .mult = 0, /* To be filled in */ | |
101 | .read = timebase_read, | |
102 | }; | |
103 | ||
d831d0b8 TB |
104 | #define DECREMENTER_MAX 0x7fffffff |
105 | ||
106 | static int decrementer_set_next_event(unsigned long evt, | |
107 | struct clock_event_device *dev); | |
108 | static void decrementer_set_mode(enum clock_event_mode mode, | |
109 | struct clock_event_device *dev); | |
110 | ||
111 | static struct clock_event_device decrementer_clockevent = { | |
112 | .name = "decrementer", | |
113 | .rating = 200, | |
8d165db1 | 114 | .shift = 0, /* To be filled in */ |
d831d0b8 TB |
115 | .mult = 0, /* To be filled in */ |
116 | .irq = 0, | |
117 | .set_next_event = decrementer_set_next_event, | |
118 | .set_mode = decrementer_set_mode, | |
119 | .features = CLOCK_EVT_FEAT_ONESHOT, | |
120 | }; | |
121 | ||
6e6b44e8 MM |
122 | struct decrementer_clock { |
123 | struct clock_event_device event; | |
124 | u64 next_tb; | |
125 | }; | |
126 | ||
127 | static DEFINE_PER_CPU(struct decrementer_clock, decrementers); | |
d831d0b8 | 128 | |
1da177e4 | 129 | #ifdef CONFIG_PPC_ISERIES |
71712b45 TB |
130 | static unsigned long __initdata iSeries_recal_titan; |
131 | static signed long __initdata iSeries_recal_tb; | |
4a4cfe38 TB |
132 | |
133 | /* Forward declaration is only needed for iSereis compiles */ | |
1c21a293 | 134 | static void __init clocksource_init(void); |
1da177e4 LT |
135 | #endif |
136 | ||
137 | #define XSEC_PER_SEC (1024*1024) | |
138 | ||
f2783c15 PM |
139 | #ifdef CONFIG_PPC64 |
140 | #define SCALE_XSEC(xsec, max) (((xsec) * max) / XSEC_PER_SEC) | |
141 | #else | |
142 | /* compute ((xsec << 12) * max) >> 32 */ | |
143 | #define SCALE_XSEC(xsec, max) mulhwu((xsec) << 12, max) | |
144 | #endif | |
145 | ||
1da177e4 LT |
146 | unsigned long tb_ticks_per_jiffy; |
147 | unsigned long tb_ticks_per_usec = 100; /* sane default */ | |
148 | EXPORT_SYMBOL(tb_ticks_per_usec); | |
149 | unsigned long tb_ticks_per_sec; | |
2cf82c02 | 150 | EXPORT_SYMBOL(tb_ticks_per_sec); /* for cputime_t conversions */ |
f2783c15 PM |
151 | u64 tb_to_xs; |
152 | unsigned tb_to_us; | |
092b8f34 | 153 | |
7fc5c784 | 154 | #define TICKLEN_SCALE NTP_SCALE_SHIFT |
1c21a293 ME |
155 | static u64 last_tick_len; /* units are ns / 2^TICKLEN_SCALE */ |
156 | static u64 ticklen_to_xs; /* 0.64 fraction */ | |
092b8f34 PM |
157 | |
158 | /* If last_tick_len corresponds to about 1/HZ seconds, then | |
159 | last_tick_len << TICKLEN_SHIFT will be about 2^63. */ | |
160 | #define TICKLEN_SHIFT (63 - 30 - TICKLEN_SCALE + SHIFT_HZ) | |
161 | ||
1da177e4 | 162 | DEFINE_SPINLOCK(rtc_lock); |
6ae3db11 | 163 | EXPORT_SYMBOL_GPL(rtc_lock); |
1da177e4 | 164 | |
fc9069fe TB |
165 | static u64 tb_to_ns_scale __read_mostly; |
166 | static unsigned tb_to_ns_shift __read_mostly; | |
167 | static unsigned long boot_tb __read_mostly; | |
1da177e4 | 168 | |
1da177e4 | 169 | extern struct timezone sys_tz; |
f2783c15 | 170 | static long timezone_offset; |
1da177e4 | 171 | |
10f7e7c1 | 172 | unsigned long ppc_proc_freq; |
1474855d | 173 | EXPORT_SYMBOL(ppc_proc_freq); |
10f7e7c1 AB |
174 | unsigned long ppc_tb_freq; |
175 | ||
eb36c288 PM |
176 | static u64 tb_last_jiffy __cacheline_aligned_in_smp; |
177 | static DEFINE_PER_CPU(u64, last_jiffy); | |
96c44507 | 178 | |
c6622f63 PM |
179 | #ifdef CONFIG_VIRT_CPU_ACCOUNTING |
180 | /* | |
181 | * Factors for converting from cputime_t (timebase ticks) to | |
182 | * jiffies, milliseconds, seconds, and clock_t (1/USER_HZ seconds). | |
183 | * These are all stored as 0.64 fixed-point binary fractions. | |
184 | */ | |
185 | u64 __cputime_jiffies_factor; | |
2cf82c02 | 186 | EXPORT_SYMBOL(__cputime_jiffies_factor); |
c6622f63 | 187 | u64 __cputime_msec_factor; |
2cf82c02 | 188 | EXPORT_SYMBOL(__cputime_msec_factor); |
c6622f63 | 189 | u64 __cputime_sec_factor; |
2cf82c02 | 190 | EXPORT_SYMBOL(__cputime_sec_factor); |
c6622f63 | 191 | u64 __cputime_clockt_factor; |
2cf82c02 | 192 | EXPORT_SYMBOL(__cputime_clockt_factor); |
06b8e878 MN |
193 | DEFINE_PER_CPU(unsigned long, cputime_last_delta); |
194 | DEFINE_PER_CPU(unsigned long, cputime_scaled_last_delta); | |
c6622f63 PM |
195 | |
196 | static void calc_cputime_factors(void) | |
197 | { | |
198 | struct div_result res; | |
199 | ||
200 | div128_by_32(HZ, 0, tb_ticks_per_sec, &res); | |
201 | __cputime_jiffies_factor = res.result_low; | |
202 | div128_by_32(1000, 0, tb_ticks_per_sec, &res); | |
203 | __cputime_msec_factor = res.result_low; | |
204 | div128_by_32(1, 0, tb_ticks_per_sec, &res); | |
205 | __cputime_sec_factor = res.result_low; | |
206 | div128_by_32(USER_HZ, 0, tb_ticks_per_sec, &res); | |
207 | __cputime_clockt_factor = res.result_low; | |
208 | } | |
209 | ||
210 | /* | |
211 | * Read the PURR on systems that have it, otherwise the timebase. | |
212 | */ | |
213 | static u64 read_purr(void) | |
214 | { | |
215 | if (cpu_has_feature(CPU_FTR_PURR)) | |
216 | return mfspr(SPRN_PURR); | |
217 | return mftb(); | |
218 | } | |
219 | ||
4603ac18 MN |
220 | /* |
221 | * Read the SPURR on systems that have it, otherwise the purr | |
222 | */ | |
223 | static u64 read_spurr(u64 purr) | |
224 | { | |
53024fe2 MM |
225 | /* |
226 | * cpus without PURR won't have a SPURR | |
227 | * We already know the former when we use this, so tell gcc | |
228 | */ | |
229 | if (cpu_has_feature(CPU_FTR_PURR) && cpu_has_feature(CPU_FTR_SPURR)) | |
4603ac18 MN |
230 | return mfspr(SPRN_SPURR); |
231 | return purr; | |
232 | } | |
233 | ||
c6622f63 PM |
234 | /* |
235 | * Account time for a transition between system, hard irq | |
236 | * or soft irq state. | |
237 | */ | |
238 | void account_system_vtime(struct task_struct *tsk) | |
239 | { | |
53024fe2 | 240 | u64 now, nowscaled, delta, deltascaled, sys_time; |
c6622f63 PM |
241 | unsigned long flags; |
242 | ||
243 | local_irq_save(flags); | |
244 | now = read_purr(); | |
4603ac18 | 245 | nowscaled = read_spurr(now); |
53024fe2 | 246 | delta = now - get_paca()->startpurr; |
4603ac18 | 247 | deltascaled = nowscaled - get_paca()->startspurr; |
53024fe2 | 248 | get_paca()->startpurr = now; |
4603ac18 | 249 | get_paca()->startspurr = nowscaled; |
c6622f63 | 250 | if (!in_interrupt()) { |
4603ac18 MN |
251 | /* deltascaled includes both user and system time. |
252 | * Hence scale it based on the purr ratio to estimate | |
253 | * the system time */ | |
53024fe2 | 254 | sys_time = get_paca()->system_time; |
2b46b567 | 255 | if (get_paca()->user_time) |
53024fe2 MM |
256 | deltascaled = deltascaled * sys_time / |
257 | (sys_time + get_paca()->user_time); | |
258 | delta += sys_time; | |
c6622f63 PM |
259 | get_paca()->system_time = 0; |
260 | } | |
79741dd3 MS |
261 | if (in_irq() || idle_task(smp_processor_id()) != tsk) |
262 | account_system_time(tsk, 0, delta, deltascaled); | |
263 | else | |
264 | account_idle_time(delta); | |
06b8e878 MN |
265 | per_cpu(cputime_last_delta, smp_processor_id()) = delta; |
266 | per_cpu(cputime_scaled_last_delta, smp_processor_id()) = deltascaled; | |
c6622f63 PM |
267 | local_irq_restore(flags); |
268 | } | |
269 | ||
270 | /* | |
271 | * Transfer the user and system times accumulated in the paca | |
272 | * by the exception entry and exit code to the generic process | |
273 | * user and system time records. | |
274 | * Must be called with interrupts disabled. | |
275 | */ | |
fa13a5a1 | 276 | void account_process_tick(struct task_struct *tsk, int user_tick) |
c6622f63 | 277 | { |
4603ac18 | 278 | cputime_t utime, utimescaled; |
c6622f63 PM |
279 | |
280 | utime = get_paca()->user_time; | |
281 | get_paca()->user_time = 0; | |
06b8e878 | 282 | utimescaled = cputime_to_scaled(utime); |
457533a7 | 283 | account_user_time(tsk, utime, utimescaled); |
c6622f63 PM |
284 | } |
285 | ||
c6622f63 PM |
286 | /* |
287 | * Stuff for accounting stolen time. | |
288 | */ | |
289 | struct cpu_purr_data { | |
290 | int initialized; /* thread is running */ | |
c6622f63 PM |
291 | u64 tb; /* last TB value read */ |
292 | u64 purr; /* last PURR value read */ | |
4603ac18 | 293 | u64 spurr; /* last SPURR value read */ |
c6622f63 PM |
294 | }; |
295 | ||
df211c8a NL |
296 | /* |
297 | * Each entry in the cpu_purr_data array is manipulated only by its | |
298 | * "owner" cpu -- usually in the timer interrupt but also occasionally | |
299 | * in process context for cpu online. As long as cpus do not touch | |
300 | * each others' cpu_purr_data, disabling local interrupts is | |
301 | * sufficient to serialize accesses. | |
302 | */ | |
c6622f63 PM |
303 | static DEFINE_PER_CPU(struct cpu_purr_data, cpu_purr_data); |
304 | ||
305 | static void snapshot_tb_and_purr(void *data) | |
306 | { | |
df211c8a | 307 | unsigned long flags; |
c6622f63 PM |
308 | struct cpu_purr_data *p = &__get_cpu_var(cpu_purr_data); |
309 | ||
df211c8a | 310 | local_irq_save(flags); |
c27da339 | 311 | p->tb = get_tb_or_rtc(); |
cbcdb93d | 312 | p->purr = mfspr(SPRN_PURR); |
c6622f63 PM |
313 | wmb(); |
314 | p->initialized = 1; | |
df211c8a | 315 | local_irq_restore(flags); |
c6622f63 PM |
316 | } |
317 | ||
318 | /* | |
319 | * Called during boot when all cpus have come up. | |
320 | */ | |
321 | void snapshot_timebases(void) | |
322 | { | |
c6622f63 PM |
323 | if (!cpu_has_feature(CPU_FTR_PURR)) |
324 | return; | |
15c8b6c1 | 325 | on_each_cpu(snapshot_tb_and_purr, NULL, 1); |
c6622f63 PM |
326 | } |
327 | ||
df211c8a NL |
328 | /* |
329 | * Must be called with interrupts disabled. | |
330 | */ | |
c6622f63 PM |
331 | void calculate_steal_time(void) |
332 | { | |
cbcdb93d | 333 | u64 tb, purr; |
c6622f63 | 334 | s64 stolen; |
cbcdb93d | 335 | struct cpu_purr_data *pme; |
c6622f63 | 336 | |
8b5621f1 | 337 | pme = &__get_cpu_var(cpu_purr_data); |
c6622f63 | 338 | if (!pme->initialized) |
db3801a8 | 339 | return; /* !CPU_FTR_PURR or early in early boot */ |
c6622f63 | 340 | tb = mftb(); |
cbcdb93d SR |
341 | purr = mfspr(SPRN_PURR); |
342 | stolen = (tb - pme->tb) - (purr - pme->purr); | |
79741dd3 MS |
343 | if (stolen > 0) { |
344 | if (idle_task(smp_processor_id()) != current) | |
345 | account_steal_time(stolen); | |
346 | else | |
347 | account_idle_time(stolen); | |
348 | } | |
c6622f63 PM |
349 | pme->tb = tb; |
350 | pme->purr = purr; | |
c6622f63 PM |
351 | } |
352 | ||
4cefebb1 | 353 | #ifdef CONFIG_PPC_SPLPAR |
c6622f63 PM |
354 | /* |
355 | * Must be called before the cpu is added to the online map when | |
356 | * a cpu is being brought up at runtime. | |
357 | */ | |
358 | static void snapshot_purr(void) | |
359 | { | |
cbcdb93d | 360 | struct cpu_purr_data *pme; |
c6622f63 PM |
361 | unsigned long flags; |
362 | ||
363 | if (!cpu_has_feature(CPU_FTR_PURR)) | |
364 | return; | |
df211c8a | 365 | local_irq_save(flags); |
8b5621f1 | 366 | pme = &__get_cpu_var(cpu_purr_data); |
cbcdb93d SR |
367 | pme->tb = mftb(); |
368 | pme->purr = mfspr(SPRN_PURR); | |
c6622f63 | 369 | pme->initialized = 1; |
df211c8a | 370 | local_irq_restore(flags); |
c6622f63 PM |
371 | } |
372 | ||
373 | #endif /* CONFIG_PPC_SPLPAR */ | |
374 | ||
375 | #else /* ! CONFIG_VIRT_CPU_ACCOUNTING */ | |
376 | #define calc_cputime_factors() | |
c6622f63 PM |
377 | #define calculate_steal_time() do { } while (0) |
378 | #endif | |
379 | ||
380 | #if !(defined(CONFIG_VIRT_CPU_ACCOUNTING) && defined(CONFIG_PPC_SPLPAR)) | |
381 | #define snapshot_purr() do { } while (0) | |
382 | #endif | |
383 | ||
384 | /* | |
385 | * Called when a cpu comes up after the system has finished booting, | |
386 | * i.e. as a result of a hotplug cpu action. | |
387 | */ | |
388 | void snapshot_timebase(void) | |
389 | { | |
c27da339 | 390 | __get_cpu_var(last_jiffy) = get_tb_or_rtc(); |
c6622f63 PM |
391 | snapshot_purr(); |
392 | } | |
393 | ||
6defa38b PM |
394 | void __delay(unsigned long loops) |
395 | { | |
396 | unsigned long start; | |
397 | int diff; | |
398 | ||
399 | if (__USE_RTC()) { | |
400 | start = get_rtcl(); | |
401 | do { | |
402 | /* the RTCL register wraps at 1000000000 */ | |
403 | diff = get_rtcl() - start; | |
404 | if (diff < 0) | |
405 | diff += 1000000000; | |
406 | } while (diff < loops); | |
407 | } else { | |
408 | start = get_tbl(); | |
409 | while (get_tbl() - start < loops) | |
410 | HMT_low(); | |
411 | HMT_medium(); | |
412 | } | |
413 | } | |
414 | EXPORT_SYMBOL(__delay); | |
415 | ||
416 | void udelay(unsigned long usecs) | |
417 | { | |
418 | __delay(tb_ticks_per_usec * usecs); | |
419 | } | |
420 | EXPORT_SYMBOL(udelay); | |
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 | { |
f2783c15 PM |
425 | /* |
426 | * tb_update_count is used to allow the userspace gettimeofday code | |
427 | * to assure itself that it sees a consistent view of the tb_to_xs and | |
428 | * stamp_xsec variables. It reads the tb_update_count, then reads | |
429 | * tb_to_xs and stamp_xsec and then reads tb_update_count again. If | |
430 | * the two values of tb_update_count match and are even then the | |
431 | * tb_to_xs and stamp_xsec values are consistent. If not, then it | |
432 | * loops back and reads them again until this criteria is met. | |
0a45d449 PM |
433 | * We expect the caller to have done the first increment of |
434 | * vdso_data->tb_update_count already. | |
f2783c15 | 435 | */ |
a7f290da BH |
436 | vdso_data->tb_orig_stamp = new_tb_stamp; |
437 | vdso_data->stamp_xsec = new_stamp_xsec; | |
438 | vdso_data->tb_to_xs = new_tb_to_xs; | |
439 | vdso_data->wtom_clock_sec = wall_to_monotonic.tv_sec; | |
440 | vdso_data->wtom_clock_nsec = wall_to_monotonic.tv_nsec; | |
597bc5c0 | 441 | vdso_data->stamp_xtime = xtime; |
0d8d4d42 | 442 | smp_wmb(); |
a7f290da | 443 | ++(vdso_data->tb_update_count); |
f2783c15 PM |
444 | } |
445 | ||
1da177e4 LT |
446 | #ifdef CONFIG_SMP |
447 | unsigned long profile_pc(struct pt_regs *regs) | |
448 | { | |
449 | unsigned long pc = instruction_pointer(regs); | |
450 | ||
451 | if (in_lock_functions(pc)) | |
452 | return regs->link; | |
453 | ||
454 | return pc; | |
455 | } | |
456 | EXPORT_SYMBOL(profile_pc); | |
457 | #endif | |
458 | ||
459 | #ifdef CONFIG_PPC_ISERIES | |
460 | ||
461 | /* | |
462 | * This function recalibrates the timebase based on the 49-bit time-of-day | |
463 | * value in the Titan chip. The Titan is much more accurate than the value | |
464 | * returned by the service processor for the timebase frequency. | |
465 | */ | |
466 | ||
71712b45 | 467 | static int __init iSeries_tb_recal(void) |
1da177e4 LT |
468 | { |
469 | struct div_result divres; | |
470 | unsigned long titan, tb; | |
71712b45 TB |
471 | |
472 | /* Make sure we only run on iSeries */ | |
473 | if (!firmware_has_feature(FW_FEATURE_ISERIES)) | |
474 | return -ENODEV; | |
475 | ||
1da177e4 LT |
476 | tb = get_tb(); |
477 | titan = HvCallXm_loadTod(); | |
478 | if ( iSeries_recal_titan ) { | |
479 | unsigned long tb_ticks = tb - iSeries_recal_tb; | |
480 | unsigned long titan_usec = (titan - iSeries_recal_titan) >> 12; | |
481 | unsigned long new_tb_ticks_per_sec = (tb_ticks * USEC_PER_SEC)/titan_usec; | |
14ea58ad JL |
482 | unsigned long new_tb_ticks_per_jiffy = |
483 | DIV_ROUND_CLOSEST(new_tb_ticks_per_sec, HZ); | |
1da177e4 LT |
484 | long tick_diff = new_tb_ticks_per_jiffy - tb_ticks_per_jiffy; |
485 | char sign = '+'; | |
486 | /* make sure tb_ticks_per_sec and tb_ticks_per_jiffy are consistent */ | |
487 | new_tb_ticks_per_sec = new_tb_ticks_per_jiffy * HZ; | |
488 | ||
489 | if ( tick_diff < 0 ) { | |
490 | tick_diff = -tick_diff; | |
491 | sign = '-'; | |
492 | } | |
493 | if ( tick_diff ) { | |
494 | if ( tick_diff < tb_ticks_per_jiffy/25 ) { | |
495 | printk( "Titan recalibrate: new tb_ticks_per_jiffy = %lu (%c%ld)\n", | |
496 | new_tb_ticks_per_jiffy, sign, tick_diff ); | |
497 | tb_ticks_per_jiffy = new_tb_ticks_per_jiffy; | |
498 | tb_ticks_per_sec = new_tb_ticks_per_sec; | |
c6622f63 | 499 | calc_cputime_factors(); |
1da177e4 | 500 | div128_by_32( XSEC_PER_SEC, 0, tb_ticks_per_sec, &divres ); |
1da177e4 | 501 | tb_to_xs = divres.result_low; |
a7f290da BH |
502 | vdso_data->tb_ticks_per_sec = tb_ticks_per_sec; |
503 | vdso_data->tb_to_xs = tb_to_xs; | |
1da177e4 LT |
504 | } |
505 | else { | |
506 | printk( "Titan recalibrate: FAILED (difference > 4 percent)\n" | |
507 | " new tb_ticks_per_jiffy = %lu\n" | |
508 | " old tb_ticks_per_jiffy = %lu\n", | |
509 | new_tb_ticks_per_jiffy, tb_ticks_per_jiffy ); | |
510 | } | |
511 | } | |
512 | } | |
513 | iSeries_recal_titan = titan; | |
514 | iSeries_recal_tb = tb; | |
71712b45 | 515 | |
4a4cfe38 TB |
516 | /* Called here as now we know accurate values for the timebase */ |
517 | clocksource_init(); | |
71712b45 | 518 | return 0; |
1da177e4 | 519 | } |
71712b45 TB |
520 | late_initcall(iSeries_tb_recal); |
521 | ||
522 | /* Called from platform early init */ | |
523 | void __init iSeries_time_init_early(void) | |
524 | { | |
525 | iSeries_recal_tb = get_tb(); | |
526 | iSeries_recal_titan = HvCallXm_loadTod(); | |
527 | } | |
528 | #endif /* CONFIG_PPC_ISERIES */ | |
1da177e4 | 529 | |
105988c0 PM |
530 | #if defined(CONFIG_PERF_COUNTERS) && defined(CONFIG_PPC32) |
531 | DEFINE_PER_CPU(u8, perf_counter_pending); | |
532 | ||
533 | void set_perf_counter_pending(void) | |
534 | { | |
535 | get_cpu_var(perf_counter_pending) = 1; | |
536 | set_dec(1); | |
537 | put_cpu_var(perf_counter_pending); | |
538 | } | |
539 | ||
540 | #define test_perf_counter_pending() __get_cpu_var(perf_counter_pending) | |
541 | #define clear_perf_counter_pending() __get_cpu_var(perf_counter_pending) = 0 | |
542 | ||
543 | #else /* CONFIG_PERF_COUNTERS && CONFIG_PPC32 */ | |
544 | ||
545 | #define test_perf_counter_pending() 0 | |
546 | #define clear_perf_counter_pending() | |
547 | ||
548 | #endif /* CONFIG_PERF_COUNTERS && CONFIG_PPC32 */ | |
549 | ||
1da177e4 LT |
550 | /* |
551 | * For iSeries shared processors, we have to let the hypervisor | |
552 | * set the hardware decrementer. We set a virtual decrementer | |
553 | * in the lppaca and call the hypervisor if the virtual | |
554 | * decrementer is less than the current value in the hardware | |
555 | * decrementer. (almost always the new decrementer value will | |
556 | * be greater than the current hardware decementer so the hypervisor | |
557 | * call will not be needed) | |
558 | */ | |
559 | ||
1da177e4 LT |
560 | /* |
561 | * timer_interrupt - gets called when the decrementer overflows, | |
562 | * with interrupts disabled. | |
563 | */ | |
c7aeffc4 | 564 | void timer_interrupt(struct pt_regs * regs) |
1da177e4 | 565 | { |
7d12e780 | 566 | struct pt_regs *old_regs; |
6e6b44e8 MM |
567 | struct decrementer_clock *decrementer = &__get_cpu_var(decrementers); |
568 | struct clock_event_device *evt = &decrementer->event; | |
d968014b | 569 | u64 now; |
d831d0b8 TB |
570 | |
571 | /* Ensure a positive value is written to the decrementer, or else | |
572 | * some CPUs will continuue to take decrementer exceptions */ | |
573 | set_dec(DECREMENTER_MAX); | |
f2783c15 PM |
574 | |
575 | #ifdef CONFIG_PPC32 | |
105988c0 PM |
576 | if (test_perf_counter_pending()) { |
577 | clear_perf_counter_pending(); | |
578 | perf_counter_do_pending(); | |
579 | } | |
f2783c15 PM |
580 | if (atomic_read(&ppc_n_lost_interrupts) != 0) |
581 | do_IRQ(regs); | |
582 | #endif | |
1da177e4 | 583 | |
d968014b | 584 | now = get_tb_or_rtc(); |
6e6b44e8 | 585 | if (now < decrementer->next_tb) { |
d968014b | 586 | /* not time for this event yet */ |
6e6b44e8 | 587 | now = decrementer->next_tb - now; |
d968014b | 588 | if (now <= DECREMENTER_MAX) |
43875cc0 | 589 | set_dec((int)now); |
d968014b PM |
590 | return; |
591 | } | |
7d12e780 | 592 | old_regs = set_irq_regs(regs); |
1da177e4 LT |
593 | irq_enter(); |
594 | ||
c6622f63 | 595 | calculate_steal_time(); |
1da177e4 | 596 | |
f2783c15 | 597 | #ifdef CONFIG_PPC_ISERIES |
501b6d29 SR |
598 | if (firmware_has_feature(FW_FEATURE_ISERIES)) |
599 | get_lppaca()->int_dword.fields.decr_int = 0; | |
f2783c15 PM |
600 | #endif |
601 | ||
d831d0b8 TB |
602 | if (evt->event_handler) |
603 | evt->event_handler(evt); | |
1da177e4 LT |
604 | |
605 | #ifdef CONFIG_PPC_ISERIES | |
501b6d29 | 606 | if (firmware_has_feature(FW_FEATURE_ISERIES) && hvlpevent_is_pending()) |
35a84c2f | 607 | process_hvlpevents(); |
1da177e4 LT |
608 | #endif |
609 | ||
f2783c15 | 610 | #ifdef CONFIG_PPC64 |
8d15a3e5 | 611 | /* collect purr register values often, for accurate calculations */ |
1ababe11 | 612 | if (firmware_has_feature(FW_FEATURE_SPLPAR)) { |
1da177e4 LT |
613 | struct cpu_usage *cu = &__get_cpu_var(cpu_usage_array); |
614 | cu->current_tb = mfspr(SPRN_PURR); | |
615 | } | |
f2783c15 | 616 | #endif |
1da177e4 LT |
617 | |
618 | irq_exit(); | |
7d12e780 | 619 | set_irq_regs(old_regs); |
1da177e4 LT |
620 | } |
621 | ||
f2783c15 PM |
622 | void wakeup_decrementer(void) |
623 | { | |
092b8f34 | 624 | unsigned long ticks; |
f2783c15 | 625 | |
f2783c15 | 626 | /* |
092b8f34 PM |
627 | * The timebase gets saved on sleep and restored on wakeup, |
628 | * so all we need to do is to reset the decrementer. | |
f2783c15 | 629 | */ |
092b8f34 PM |
630 | ticks = tb_ticks_since(__get_cpu_var(last_jiffy)); |
631 | if (ticks < tb_ticks_per_jiffy) | |
632 | ticks = tb_ticks_per_jiffy - ticks; | |
633 | else | |
634 | ticks = 1; | |
635 | set_dec(ticks); | |
f2783c15 PM |
636 | } |
637 | ||
7ac5dde9 SW |
638 | #ifdef CONFIG_SUSPEND |
639 | void generic_suspend_disable_irqs(void) | |
640 | { | |
641 | preempt_disable(); | |
642 | ||
643 | /* Disable the decrementer, so that it doesn't interfere | |
644 | * with suspending. | |
645 | */ | |
646 | ||
647 | set_dec(0x7fffffff); | |
648 | local_irq_disable(); | |
649 | set_dec(0x7fffffff); | |
650 | } | |
651 | ||
652 | void generic_suspend_enable_irqs(void) | |
653 | { | |
654 | wakeup_decrementer(); | |
655 | ||
656 | local_irq_enable(); | |
657 | preempt_enable(); | |
658 | } | |
659 | ||
660 | /* Overrides the weak version in kernel/power/main.c */ | |
661 | void arch_suspend_disable_irqs(void) | |
662 | { | |
663 | if (ppc_md.suspend_disable_irqs) | |
664 | ppc_md.suspend_disable_irqs(); | |
665 | generic_suspend_disable_irqs(); | |
666 | } | |
667 | ||
668 | /* Overrides the weak version in kernel/power/main.c */ | |
669 | void arch_suspend_enable_irqs(void) | |
670 | { | |
671 | generic_suspend_enable_irqs(); | |
672 | if (ppc_md.suspend_enable_irqs) | |
673 | ppc_md.suspend_enable_irqs(); | |
674 | } | |
675 | #endif | |
676 | ||
a5b518ed | 677 | #ifdef CONFIG_SMP |
f2783c15 PM |
678 | void __init smp_space_timers(unsigned int max_cpus) |
679 | { | |
680 | int i; | |
eb36c288 | 681 | u64 previous_tb = per_cpu(last_jiffy, boot_cpuid); |
f2783c15 | 682 | |
cbe62e2b PM |
683 | /* make sure tb > per_cpu(last_jiffy, cpu) for all cpus always */ |
684 | previous_tb -= tb_ticks_per_jiffy; | |
e147ec8f | 685 | |
0e551954 | 686 | for_each_possible_cpu(i) { |
c6622f63 PM |
687 | if (i == boot_cpuid) |
688 | continue; | |
e147ec8f | 689 | per_cpu(last_jiffy, i) = previous_tb; |
f2783c15 PM |
690 | } |
691 | } | |
692 | #endif | |
693 | ||
1da177e4 LT |
694 | /* |
695 | * Scheduler clock - returns current time in nanosec units. | |
696 | * | |
697 | * Note: mulhdu(a, b) (multiply high double unsigned) returns | |
698 | * the high 64 bits of a * b, i.e. (a * b) >> 64, where a and b | |
699 | * are 64-bit unsigned numbers. | |
700 | */ | |
701 | unsigned long long sched_clock(void) | |
702 | { | |
96c44507 PM |
703 | if (__USE_RTC()) |
704 | return get_rtc(); | |
fc9069fe | 705 | return mulhdu(get_tb() - boot_tb, tb_to_ns_scale) << tb_to_ns_shift; |
1da177e4 LT |
706 | } |
707 | ||
0bb474a4 | 708 | static int __init get_freq(char *name, int cells, unsigned long *val) |
10f7e7c1 AB |
709 | { |
710 | struct device_node *cpu; | |
a7f67bdf | 711 | const unsigned int *fp; |
0bb474a4 | 712 | int found = 0; |
10f7e7c1 | 713 | |
0bb474a4 | 714 | /* The cpu node should have timebase and clock frequency properties */ |
10f7e7c1 AB |
715 | cpu = of_find_node_by_type(NULL, "cpu"); |
716 | ||
d8a8188d | 717 | if (cpu) { |
e2eb6392 | 718 | fp = of_get_property(cpu, name, NULL); |
d8a8188d | 719 | if (fp) { |
0bb474a4 | 720 | found = 1; |
a4dc7ff0 | 721 | *val = of_read_ulong(fp, cells); |
10f7e7c1 | 722 | } |
0bb474a4 AB |
723 | |
724 | of_node_put(cpu); | |
10f7e7c1 | 725 | } |
0bb474a4 AB |
726 | |
727 | return found; | |
728 | } | |
729 | ||
77c0a700 BH |
730 | /* should become __cpuinit when secondary_cpu_time_init also is */ |
731 | void start_cpu_decrementer(void) | |
732 | { | |
733 | #if defined(CONFIG_BOOKE) || defined(CONFIG_40x) | |
734 | /* Clear any pending timer interrupts */ | |
735 | mtspr(SPRN_TSR, TSR_ENW | TSR_WIS | TSR_DIS | TSR_FIS); | |
736 | ||
737 | /* Enable decrementer interrupt */ | |
738 | mtspr(SPRN_TCR, TCR_DIE); | |
739 | #endif /* defined(CONFIG_BOOKE) || defined(CONFIG_40x) */ | |
740 | } | |
741 | ||
0bb474a4 AB |
742 | void __init generic_calibrate_decr(void) |
743 | { | |
744 | ppc_tb_freq = DEFAULT_TB_FREQ; /* hardcoded default */ | |
745 | ||
746 | if (!get_freq("ibm,extended-timebase-frequency", 2, &ppc_tb_freq) && | |
747 | !get_freq("timebase-frequency", 1, &ppc_tb_freq)) { | |
748 | ||
10f7e7c1 AB |
749 | printk(KERN_ERR "WARNING: Estimating decrementer frequency " |
750 | "(not found)\n"); | |
0bb474a4 | 751 | } |
10f7e7c1 | 752 | |
0bb474a4 AB |
753 | ppc_proc_freq = DEFAULT_PROC_FREQ; /* hardcoded default */ |
754 | ||
755 | if (!get_freq("ibm,extended-clock-frequency", 2, &ppc_proc_freq) && | |
756 | !get_freq("clock-frequency", 1, &ppc_proc_freq)) { | |
757 | ||
758 | printk(KERN_ERR "WARNING: Estimating processor frequency " | |
759 | "(not found)\n"); | |
10f7e7c1 | 760 | } |
10f7e7c1 | 761 | } |
10f7e7c1 | 762 | |
aa3be5f3 | 763 | int update_persistent_clock(struct timespec now) |
f2783c15 PM |
764 | { |
765 | struct rtc_time tm; | |
766 | ||
aa3be5f3 TB |
767 | if (!ppc_md.set_rtc_time) |
768 | return 0; | |
769 | ||
770 | to_tm(now.tv_sec + 1 + timezone_offset, &tm); | |
771 | tm.tm_year -= 1900; | |
772 | tm.tm_mon -= 1; | |
773 | ||
774 | return ppc_md.set_rtc_time(&tm); | |
775 | } | |
776 | ||
777 | unsigned long read_persistent_clock(void) | |
778 | { | |
779 | struct rtc_time tm; | |
780 | static int first = 1; | |
781 | ||
782 | /* XXX this is a litle fragile but will work okay in the short term */ | |
783 | if (first) { | |
784 | first = 0; | |
785 | if (ppc_md.time_init) | |
786 | timezone_offset = ppc_md.time_init(); | |
787 | ||
788 | /* get_boot_time() isn't guaranteed to be safe to call late */ | |
789 | if (ppc_md.get_boot_time) | |
790 | return ppc_md.get_boot_time() -timezone_offset; | |
791 | } | |
f2783c15 PM |
792 | if (!ppc_md.get_rtc_time) |
793 | return 0; | |
794 | ppc_md.get_rtc_time(&tm); | |
795 | return mktime(tm.tm_year+1900, tm.tm_mon+1, tm.tm_mday, | |
796 | tm.tm_hour, tm.tm_min, tm.tm_sec); | |
797 | } | |
798 | ||
4a4cfe38 | 799 | /* clocksource code */ |
8e19608e | 800 | static cycle_t rtc_read(struct clocksource *cs) |
4a4cfe38 TB |
801 | { |
802 | return (cycle_t)get_rtc(); | |
803 | } | |
804 | ||
8e19608e | 805 | static cycle_t timebase_read(struct clocksource *cs) |
4a4cfe38 TB |
806 | { |
807 | return (cycle_t)get_tb(); | |
808 | } | |
809 | ||
810 | void update_vsyscall(struct timespec *wall_time, struct clocksource *clock) | |
811 | { | |
812 | u64 t2x, stamp_xsec; | |
813 | ||
814 | if (clock != &clocksource_timebase) | |
815 | return; | |
816 | ||
817 | /* Make userspace gettimeofday spin until we're done. */ | |
818 | ++vdso_data->tb_update_count; | |
819 | smp_mb(); | |
820 | ||
821 | /* XXX this assumes clock->shift == 22 */ | |
822 | /* 4611686018 ~= 2^(20+64-22) / 1e9 */ | |
823 | t2x = (u64) clock->mult * 4611686018ULL; | |
824 | stamp_xsec = (u64) xtime.tv_nsec * XSEC_PER_SEC; | |
825 | do_div(stamp_xsec, 1000000000); | |
826 | stamp_xsec += (u64) xtime.tv_sec * XSEC_PER_SEC; | |
827 | update_gtod(clock->cycle_last, stamp_xsec, t2x); | |
828 | } | |
829 | ||
830 | void update_vsyscall_tz(void) | |
831 | { | |
832 | /* Make userspace gettimeofday spin until we're done. */ | |
833 | ++vdso_data->tb_update_count; | |
834 | smp_mb(); | |
835 | vdso_data->tz_minuteswest = sys_tz.tz_minuteswest; | |
836 | vdso_data->tz_dsttime = sys_tz.tz_dsttime; | |
837 | smp_mb(); | |
838 | ++vdso_data->tb_update_count; | |
839 | } | |
840 | ||
1c21a293 | 841 | static void __init clocksource_init(void) |
4a4cfe38 TB |
842 | { |
843 | struct clocksource *clock; | |
844 | ||
845 | if (__USE_RTC()) | |
846 | clock = &clocksource_rtc; | |
847 | else | |
848 | clock = &clocksource_timebase; | |
849 | ||
850 | clock->mult = clocksource_hz2mult(tb_ticks_per_sec, clock->shift); | |
851 | ||
852 | if (clocksource_register(clock)) { | |
853 | printk(KERN_ERR "clocksource: %s is already registered\n", | |
854 | clock->name); | |
855 | return; | |
856 | } | |
857 | ||
858 | printk(KERN_INFO "clocksource: %s mult[%x] shift[%d] registered\n", | |
859 | clock->name, clock->mult, clock->shift); | |
860 | } | |
861 | ||
d831d0b8 TB |
862 | static int decrementer_set_next_event(unsigned long evt, |
863 | struct clock_event_device *dev) | |
864 | { | |
6e6b44e8 | 865 | __get_cpu_var(decrementers).next_tb = get_tb_or_rtc() + evt; |
d831d0b8 TB |
866 | set_dec(evt); |
867 | return 0; | |
868 | } | |
869 | ||
870 | static void decrementer_set_mode(enum clock_event_mode mode, | |
871 | struct clock_event_device *dev) | |
872 | { | |
873 | if (mode != CLOCK_EVT_MODE_ONESHOT) | |
874 | decrementer_set_next_event(DECREMENTER_MAX, dev); | |
875 | } | |
876 | ||
8d165db1 AB |
877 | static void __init setup_clockevent_multiplier(unsigned long hz) |
878 | { | |
879 | u64 mult, shift = 32; | |
880 | ||
881 | while (1) { | |
882 | mult = div_sc(hz, NSEC_PER_SEC, shift); | |
883 | if (mult && (mult >> 32UL) == 0UL) | |
884 | break; | |
885 | ||
886 | shift--; | |
887 | } | |
888 | ||
889 | decrementer_clockevent.shift = shift; | |
890 | decrementer_clockevent.mult = mult; | |
891 | } | |
892 | ||
d831d0b8 TB |
893 | static void register_decrementer_clockevent(int cpu) |
894 | { | |
6e6b44e8 | 895 | struct clock_event_device *dec = &per_cpu(decrementers, cpu).event; |
d831d0b8 TB |
896 | |
897 | *dec = decrementer_clockevent; | |
320ab2b0 | 898 | dec->cpumask = cpumask_of(cpu); |
d831d0b8 | 899 | |
0302f12e | 900 | printk(KERN_DEBUG "clockevent: %s mult[%lx] shift[%d] cpu[%d]\n", |
d831d0b8 TB |
901 | dec->name, dec->mult, dec->shift, cpu); |
902 | ||
903 | clockevents_register_device(dec); | |
904 | } | |
905 | ||
c481887f | 906 | static void __init init_decrementer_clockevent(void) |
d831d0b8 TB |
907 | { |
908 | int cpu = smp_processor_id(); | |
909 | ||
8d165db1 | 910 | setup_clockevent_multiplier(ppc_tb_freq); |
d831d0b8 TB |
911 | decrementer_clockevent.max_delta_ns = |
912 | clockevent_delta2ns(DECREMENTER_MAX, &decrementer_clockevent); | |
43875cc0 PM |
913 | decrementer_clockevent.min_delta_ns = |
914 | clockevent_delta2ns(2, &decrementer_clockevent); | |
d831d0b8 TB |
915 | |
916 | register_decrementer_clockevent(cpu); | |
917 | } | |
918 | ||
919 | void secondary_cpu_time_init(void) | |
920 | { | |
77c0a700 BH |
921 | /* Start the decrementer on CPUs that have manual control |
922 | * such as BookE | |
923 | */ | |
924 | start_cpu_decrementer(); | |
925 | ||
d831d0b8 TB |
926 | /* FIME: Should make unrelatred change to move snapshot_timebase |
927 | * call here ! */ | |
928 | register_decrementer_clockevent(smp_processor_id()); | |
929 | } | |
930 | ||
f2783c15 | 931 | /* This function is only called on the boot processor */ |
1da177e4 LT |
932 | void __init time_init(void) |
933 | { | |
1da177e4 | 934 | unsigned long flags; |
1da177e4 | 935 | struct div_result res; |
092b8f34 | 936 | u64 scale, x; |
f2783c15 PM |
937 | unsigned shift; |
938 | ||
96c44507 PM |
939 | if (__USE_RTC()) { |
940 | /* 601 processor: dec counts down by 128 every 128ns */ | |
941 | ppc_tb_freq = 1000000000; | |
eb36c288 | 942 | tb_last_jiffy = get_rtcl(); |
96c44507 PM |
943 | } else { |
944 | /* Normal PowerPC with timebase register */ | |
945 | ppc_md.calibrate_decr(); | |
224ad80a | 946 | printk(KERN_DEBUG "time_init: decrementer frequency = %lu.%.6lu MHz\n", |
96c44507 | 947 | ppc_tb_freq / 1000000, ppc_tb_freq % 1000000); |
224ad80a | 948 | printk(KERN_DEBUG "time_init: processor frequency = %lu.%.6lu MHz\n", |
96c44507 | 949 | ppc_proc_freq / 1000000, ppc_proc_freq % 1000000); |
eb36c288 | 950 | tb_last_jiffy = get_tb(); |
96c44507 | 951 | } |
374e99d4 PM |
952 | |
953 | tb_ticks_per_jiffy = ppc_tb_freq / HZ; | |
092b8f34 | 954 | tb_ticks_per_sec = ppc_tb_freq; |
374e99d4 PM |
955 | tb_ticks_per_usec = ppc_tb_freq / 1000000; |
956 | tb_to_us = mulhwu_scale_factor(ppc_tb_freq, 1000000); | |
c6622f63 | 957 | calc_cputime_factors(); |
092b8f34 PM |
958 | |
959 | /* | |
960 | * Calculate the length of each tick in ns. It will not be | |
961 | * exactly 1e9/HZ unless ppc_tb_freq is divisible by HZ. | |
962 | * We compute 1e9 * tb_ticks_per_jiffy / ppc_tb_freq, | |
963 | * rounded up. | |
964 | */ | |
965 | x = (u64) NSEC_PER_SEC * tb_ticks_per_jiffy + ppc_tb_freq - 1; | |
966 | do_div(x, ppc_tb_freq); | |
967 | tick_nsec = x; | |
968 | last_tick_len = x << TICKLEN_SCALE; | |
969 | ||
970 | /* | |
971 | * Compute ticklen_to_xs, which is a factor which gets multiplied | |
972 | * by (last_tick_len << TICKLEN_SHIFT) to get a tb_to_xs value. | |
973 | * It is computed as: | |
974 | * ticklen_to_xs = 2^N / (tb_ticks_per_jiffy * 1e9) | |
975 | * where N = 64 + 20 - TICKLEN_SCALE - TICKLEN_SHIFT | |
0a45d449 PM |
976 | * which turns out to be N = 51 - SHIFT_HZ. |
977 | * This gives the result as a 0.64 fixed-point fraction. | |
978 | * That value is reduced by an offset amounting to 1 xsec per | |
979 | * 2^31 timebase ticks to avoid problems with time going backwards | |
980 | * by 1 xsec when we do timer_recalc_offset due to losing the | |
981 | * fractional xsec. That offset is equal to ppc_tb_freq/2^51 | |
982 | * since there are 2^20 xsec in a second. | |
092b8f34 | 983 | */ |
0a45d449 PM |
984 | div128_by_32((1ULL << 51) - ppc_tb_freq, 0, |
985 | tb_ticks_per_jiffy << SHIFT_HZ, &res); | |
092b8f34 PM |
986 | div128_by_32(res.result_high, res.result_low, NSEC_PER_SEC, &res); |
987 | ticklen_to_xs = res.result_low; | |
988 | ||
989 | /* Compute tb_to_xs from tick_nsec */ | |
990 | tb_to_xs = mulhdu(last_tick_len << TICKLEN_SHIFT, ticklen_to_xs); | |
374e99d4 | 991 | |
1da177e4 LT |
992 | /* |
993 | * Compute scale factor for sched_clock. | |
994 | * The calibrate_decr() function has set tb_ticks_per_sec, | |
995 | * which is the timebase frequency. | |
996 | * We compute 1e9 * 2^64 / tb_ticks_per_sec and interpret | |
997 | * the 128-bit result as a 64.64 fixed-point number. | |
998 | * We then shift that number right until it is less than 1.0, | |
999 | * giving us the scale factor and shift count to use in | |
1000 | * sched_clock(). | |
1001 | */ | |
1002 | div128_by_32(1000000000, 0, tb_ticks_per_sec, &res); | |
1003 | scale = res.result_low; | |
1004 | for (shift = 0; res.result_high != 0; ++shift) { | |
1005 | scale = (scale >> 1) | (res.result_high << 63); | |
1006 | res.result_high >>= 1; | |
1007 | } | |
1008 | tb_to_ns_scale = scale; | |
1009 | tb_to_ns_shift = shift; | |
fc9069fe | 1010 | /* Save the current timebase to pretty up CONFIG_PRINTK_TIME */ |
c27da339 | 1011 | boot_tb = get_tb_or_rtc(); |
1da177e4 | 1012 | |
1da177e4 | 1013 | write_seqlock_irqsave(&xtime_lock, flags); |
092b8f34 PM |
1014 | |
1015 | /* If platform provided a timezone (pmac), we correct the time */ | |
1016 | if (timezone_offset) { | |
1017 | sys_tz.tz_minuteswest = -timezone_offset / 60; | |
1018 | sys_tz.tz_dsttime = 0; | |
092b8f34 PM |
1019 | } |
1020 | ||
a7f290da BH |
1021 | vdso_data->tb_orig_stamp = tb_last_jiffy; |
1022 | vdso_data->tb_update_count = 0; | |
1023 | vdso_data->tb_ticks_per_sec = tb_ticks_per_sec; | |
092b8f34 | 1024 | vdso_data->stamp_xsec = (u64) xtime.tv_sec * XSEC_PER_SEC; |
a7f290da | 1025 | vdso_data->tb_to_xs = tb_to_xs; |
1da177e4 | 1026 | |
1da177e4 LT |
1027 | write_sequnlock_irqrestore(&xtime_lock, flags); |
1028 | ||
77c0a700 BH |
1029 | /* Start the decrementer on CPUs that have manual control |
1030 | * such as BookE | |
1031 | */ | |
1032 | start_cpu_decrementer(); | |
1033 | ||
4a4cfe38 TB |
1034 | /* Register the clocksource, if we're not running on iSeries */ |
1035 | if (!firmware_has_feature(FW_FEATURE_ISERIES)) | |
1036 | clocksource_init(); | |
1037 | ||
d831d0b8 | 1038 | init_decrementer_clockevent(); |
1da177e4 LT |
1039 | } |
1040 | ||
1da177e4 | 1041 | |
1da177e4 LT |
1042 | #define FEBRUARY 2 |
1043 | #define STARTOFTIME 1970 | |
1044 | #define SECDAY 86400L | |
1045 | #define SECYR (SECDAY * 365) | |
f2783c15 PM |
1046 | #define leapyear(year) ((year) % 4 == 0 && \ |
1047 | ((year) % 100 != 0 || (year) % 400 == 0)) | |
1da177e4 LT |
1048 | #define days_in_year(a) (leapyear(a) ? 366 : 365) |
1049 | #define days_in_month(a) (month_days[(a) - 1]) | |
1050 | ||
1051 | static int month_days[12] = { | |
1052 | 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 | |
1053 | }; | |
1054 | ||
1055 | /* | |
1056 | * This only works for the Gregorian calendar - i.e. after 1752 (in the UK) | |
1057 | */ | |
1058 | void GregorianDay(struct rtc_time * tm) | |
1059 | { | |
1060 | int leapsToDate; | |
1061 | int lastYear; | |
1062 | int day; | |
1063 | int MonthOffset[] = { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 }; | |
1064 | ||
f2783c15 | 1065 | lastYear = tm->tm_year - 1; |
1da177e4 LT |
1066 | |
1067 | /* | |
1068 | * Number of leap corrections to apply up to end of last year | |
1069 | */ | |
f2783c15 | 1070 | leapsToDate = lastYear / 4 - lastYear / 100 + lastYear / 400; |
1da177e4 LT |
1071 | |
1072 | /* | |
1073 | * This year is a leap year if it is divisible by 4 except when it is | |
1074 | * divisible by 100 unless it is divisible by 400 | |
1075 | * | |
f2783c15 | 1076 | * e.g. 1904 was a leap year, 1900 was not, 1996 is, and 2000 was |
1da177e4 | 1077 | */ |
f2783c15 | 1078 | day = tm->tm_mon > 2 && leapyear(tm->tm_year); |
1da177e4 LT |
1079 | |
1080 | day += lastYear*365 + leapsToDate + MonthOffset[tm->tm_mon-1] + | |
1081 | tm->tm_mday; | |
1082 | ||
f2783c15 | 1083 | tm->tm_wday = day % 7; |
1da177e4 LT |
1084 | } |
1085 | ||
1086 | void to_tm(int tim, struct rtc_time * tm) | |
1087 | { | |
1088 | register int i; | |
1089 | register long hms, day; | |
1090 | ||
1091 | day = tim / SECDAY; | |
1092 | hms = tim % SECDAY; | |
1093 | ||
1094 | /* Hours, minutes, seconds are easy */ | |
1095 | tm->tm_hour = hms / 3600; | |
1096 | tm->tm_min = (hms % 3600) / 60; | |
1097 | tm->tm_sec = (hms % 3600) % 60; | |
1098 | ||
1099 | /* Number of years in days */ | |
1100 | for (i = STARTOFTIME; day >= days_in_year(i); i++) | |
1101 | day -= days_in_year(i); | |
1102 | tm->tm_year = i; | |
1103 | ||
1104 | /* Number of months in days left */ | |
1105 | if (leapyear(tm->tm_year)) | |
1106 | days_in_month(FEBRUARY) = 29; | |
1107 | for (i = 1; day >= days_in_month(i); i++) | |
1108 | day -= days_in_month(i); | |
1109 | days_in_month(FEBRUARY) = 28; | |
1110 | tm->tm_mon = i; | |
1111 | ||
1112 | /* Days are what is left over (+1) from all that. */ | |
1113 | tm->tm_mday = day + 1; | |
1114 | ||
1115 | /* | |
1116 | * Determine the day of week | |
1117 | */ | |
1118 | GregorianDay(tm); | |
1119 | } | |
1120 | ||
1121 | /* Auxiliary function to compute scaling factors */ | |
1122 | /* Actually the choice of a timebase running at 1/4 the of the bus | |
1123 | * frequency giving resolution of a few tens of nanoseconds is quite nice. | |
1124 | * It makes this computation very precise (27-28 bits typically) which | |
1125 | * is optimistic considering the stability of most processor clock | |
1126 | * oscillators and the precision with which the timebase frequency | |
1127 | * is measured but does not harm. | |
1128 | */ | |
f2783c15 PM |
1129 | unsigned mulhwu_scale_factor(unsigned inscale, unsigned outscale) |
1130 | { | |
1da177e4 LT |
1131 | unsigned mlt=0, tmp, err; |
1132 | /* No concern for performance, it's done once: use a stupid | |
1133 | * but safe and compact method to find the multiplier. | |
1134 | */ | |
1135 | ||
1136 | for (tmp = 1U<<31; tmp != 0; tmp >>= 1) { | |
f2783c15 PM |
1137 | if (mulhwu(inscale, mlt|tmp) < outscale) |
1138 | mlt |= tmp; | |
1da177e4 LT |
1139 | } |
1140 | ||
1141 | /* We might still be off by 1 for the best approximation. | |
1142 | * A side effect of this is that if outscale is too large | |
1143 | * the returned value will be zero. | |
1144 | * Many corner cases have been checked and seem to work, | |
1145 | * some might have been forgotten in the test however. | |
1146 | */ | |
1147 | ||
f2783c15 PM |
1148 | err = inscale * (mlt+1); |
1149 | if (err <= inscale/2) | |
1150 | mlt++; | |
1da177e4 | 1151 | return mlt; |
f2783c15 | 1152 | } |
1da177e4 LT |
1153 | |
1154 | /* | |
1155 | * Divide a 128-bit dividend by a 32-bit divisor, leaving a 128 bit | |
1156 | * result. | |
1157 | */ | |
f2783c15 PM |
1158 | void div128_by_32(u64 dividend_high, u64 dividend_low, |
1159 | unsigned divisor, struct div_result *dr) | |
1da177e4 | 1160 | { |
f2783c15 PM |
1161 | unsigned long a, b, c, d; |
1162 | unsigned long w, x, y, z; | |
1163 | u64 ra, rb, rc; | |
1da177e4 LT |
1164 | |
1165 | a = dividend_high >> 32; | |
1166 | b = dividend_high & 0xffffffff; | |
1167 | c = dividend_low >> 32; | |
1168 | d = dividend_low & 0xffffffff; | |
1169 | ||
f2783c15 PM |
1170 | w = a / divisor; |
1171 | ra = ((u64)(a - (w * divisor)) << 32) + b; | |
1172 | ||
f2783c15 PM |
1173 | rb = ((u64) do_div(ra, divisor) << 32) + c; |
1174 | x = ra; | |
1da177e4 | 1175 | |
f2783c15 PM |
1176 | rc = ((u64) do_div(rb, divisor) << 32) + d; |
1177 | y = rb; | |
1178 | ||
1179 | do_div(rc, divisor); | |
1180 | z = rc; | |
1da177e4 | 1181 | |
f2783c15 PM |
1182 | dr->result_high = ((u64)w << 32) + x; |
1183 | dr->result_low = ((u64)y << 32) + z; | |
1da177e4 LT |
1184 | |
1185 | } | |
bcd68a70 | 1186 | |
177996e6 BH |
1187 | /* We don't need to calibrate delay, we use the CPU timebase for that */ |
1188 | void calibrate_delay(void) | |
1189 | { | |
1190 | /* Some generic code (such as spinlock debug) use loops_per_jiffy | |
1191 | * as the number of __delay(1) in a jiffy, so make it so | |
1192 | */ | |
1193 | loops_per_jiffy = tb_ticks_per_jiffy; | |
1194 | } | |
1195 | ||
bcd68a70 GU |
1196 | static int __init rtc_init(void) |
1197 | { | |
1198 | struct platform_device *pdev; | |
1199 | ||
1200 | if (!ppc_md.get_rtc_time) | |
1201 | return -ENODEV; | |
1202 | ||
1203 | pdev = platform_device_register_simple("rtc-generic", -1, NULL, 0); | |
1204 | if (IS_ERR(pdev)) | |
1205 | return PTR_ERR(pdev); | |
1206 | ||
1207 | return 0; | |
1208 | } | |
1209 | ||
1210 | module_init(rtc_init); |