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> |
cdd6c482 | 56 | #include <linux/perf_event.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 */ |
f2783c15 PM |
152 | u64 tb_to_xs; |
153 | unsigned tb_to_us; | |
092b8f34 | 154 | |
7fc5c784 | 155 | #define TICKLEN_SCALE NTP_SCALE_SHIFT |
1c21a293 ME |
156 | static u64 last_tick_len; /* units are ns / 2^TICKLEN_SCALE */ |
157 | static u64 ticklen_to_xs; /* 0.64 fraction */ | |
092b8f34 PM |
158 | |
159 | /* If last_tick_len corresponds to about 1/HZ seconds, then | |
160 | last_tick_len << TICKLEN_SHIFT will be about 2^63. */ | |
161 | #define TICKLEN_SHIFT (63 - 30 - TICKLEN_SCALE + SHIFT_HZ) | |
162 | ||
1da177e4 | 163 | DEFINE_SPINLOCK(rtc_lock); |
6ae3db11 | 164 | EXPORT_SYMBOL_GPL(rtc_lock); |
1da177e4 | 165 | |
fc9069fe TB |
166 | static u64 tb_to_ns_scale __read_mostly; |
167 | static unsigned tb_to_ns_shift __read_mostly; | |
168 | static unsigned long boot_tb __read_mostly; | |
1da177e4 | 169 | |
1da177e4 | 170 | extern struct timezone sys_tz; |
f2783c15 | 171 | static long timezone_offset; |
1da177e4 | 172 | |
10f7e7c1 | 173 | unsigned long ppc_proc_freq; |
1474855d | 174 | EXPORT_SYMBOL(ppc_proc_freq); |
10f7e7c1 AB |
175 | unsigned long ppc_tb_freq; |
176 | ||
eb36c288 PM |
177 | static u64 tb_last_jiffy __cacheline_aligned_in_smp; |
178 | static DEFINE_PER_CPU(u64, last_jiffy); | |
96c44507 | 179 | |
c6622f63 PM |
180 | #ifdef CONFIG_VIRT_CPU_ACCOUNTING |
181 | /* | |
182 | * Factors for converting from cputime_t (timebase ticks) to | |
183 | * jiffies, milliseconds, seconds, and clock_t (1/USER_HZ seconds). | |
184 | * These are all stored as 0.64 fixed-point binary fractions. | |
185 | */ | |
186 | u64 __cputime_jiffies_factor; | |
2cf82c02 | 187 | EXPORT_SYMBOL(__cputime_jiffies_factor); |
c6622f63 | 188 | u64 __cputime_msec_factor; |
2cf82c02 | 189 | EXPORT_SYMBOL(__cputime_msec_factor); |
c6622f63 | 190 | u64 __cputime_sec_factor; |
2cf82c02 | 191 | EXPORT_SYMBOL(__cputime_sec_factor); |
c6622f63 | 192 | u64 __cputime_clockt_factor; |
2cf82c02 | 193 | EXPORT_SYMBOL(__cputime_clockt_factor); |
06b8e878 MN |
194 | DEFINE_PER_CPU(unsigned long, cputime_last_delta); |
195 | DEFINE_PER_CPU(unsigned long, cputime_scaled_last_delta); | |
c6622f63 | 196 | |
a42548a1 SG |
197 | cputime_t cputime_one_jiffy; |
198 | ||
c6622f63 PM |
199 | static void calc_cputime_factors(void) |
200 | { | |
201 | struct div_result res; | |
202 | ||
203 | div128_by_32(HZ, 0, tb_ticks_per_sec, &res); | |
204 | __cputime_jiffies_factor = res.result_low; | |
205 | div128_by_32(1000, 0, tb_ticks_per_sec, &res); | |
206 | __cputime_msec_factor = res.result_low; | |
207 | div128_by_32(1, 0, tb_ticks_per_sec, &res); | |
208 | __cputime_sec_factor = res.result_low; | |
209 | div128_by_32(USER_HZ, 0, tb_ticks_per_sec, &res); | |
210 | __cputime_clockt_factor = res.result_low; | |
211 | } | |
212 | ||
213 | /* | |
214 | * Read the PURR on systems that have it, otherwise the timebase. | |
215 | */ | |
216 | static u64 read_purr(void) | |
217 | { | |
218 | if (cpu_has_feature(CPU_FTR_PURR)) | |
219 | return mfspr(SPRN_PURR); | |
220 | return mftb(); | |
221 | } | |
222 | ||
4603ac18 MN |
223 | /* |
224 | * Read the SPURR on systems that have it, otherwise the purr | |
225 | */ | |
226 | static u64 read_spurr(u64 purr) | |
227 | { | |
53024fe2 MM |
228 | /* |
229 | * cpus without PURR won't have a SPURR | |
230 | * We already know the former when we use this, so tell gcc | |
231 | */ | |
232 | if (cpu_has_feature(CPU_FTR_PURR) && cpu_has_feature(CPU_FTR_SPURR)) | |
4603ac18 MN |
233 | return mfspr(SPRN_SPURR); |
234 | return purr; | |
235 | } | |
236 | ||
c6622f63 PM |
237 | /* |
238 | * Account time for a transition between system, hard irq | |
239 | * or soft irq state. | |
240 | */ | |
241 | void account_system_vtime(struct task_struct *tsk) | |
242 | { | |
53024fe2 | 243 | u64 now, nowscaled, delta, deltascaled, sys_time; |
c6622f63 PM |
244 | unsigned long flags; |
245 | ||
246 | local_irq_save(flags); | |
247 | now = read_purr(); | |
4603ac18 | 248 | nowscaled = read_spurr(now); |
53024fe2 | 249 | delta = now - get_paca()->startpurr; |
4603ac18 | 250 | deltascaled = nowscaled - get_paca()->startspurr; |
53024fe2 | 251 | get_paca()->startpurr = now; |
4603ac18 | 252 | get_paca()->startspurr = nowscaled; |
c6622f63 | 253 | if (!in_interrupt()) { |
4603ac18 MN |
254 | /* deltascaled includes both user and system time. |
255 | * Hence scale it based on the purr ratio to estimate | |
256 | * the system time */ | |
53024fe2 | 257 | sys_time = get_paca()->system_time; |
2b46b567 | 258 | if (get_paca()->user_time) |
53024fe2 MM |
259 | deltascaled = deltascaled * sys_time / |
260 | (sys_time + get_paca()->user_time); | |
261 | delta += sys_time; | |
c6622f63 PM |
262 | get_paca()->system_time = 0; |
263 | } | |
79741dd3 MS |
264 | if (in_irq() || idle_task(smp_processor_id()) != tsk) |
265 | account_system_time(tsk, 0, delta, deltascaled); | |
266 | else | |
267 | account_idle_time(delta); | |
61c03ddb AB |
268 | __get_cpu_var(cputime_last_delta) = delta; |
269 | __get_cpu_var(cputime_scaled_last_delta) = deltascaled; | |
c6622f63 PM |
270 | local_irq_restore(flags); |
271 | } | |
4ab79aa8 | 272 | EXPORT_SYMBOL_GPL(account_system_vtime); |
c6622f63 PM |
273 | |
274 | /* | |
275 | * Transfer the user and system times accumulated in the paca | |
276 | * by the exception entry and exit code to the generic process | |
277 | * user and system time records. | |
278 | * Must be called with interrupts disabled. | |
279 | */ | |
fa13a5a1 | 280 | void account_process_tick(struct task_struct *tsk, int user_tick) |
c6622f63 | 281 | { |
4603ac18 | 282 | cputime_t utime, utimescaled; |
c6622f63 PM |
283 | |
284 | utime = get_paca()->user_time; | |
285 | get_paca()->user_time = 0; | |
06b8e878 | 286 | utimescaled = cputime_to_scaled(utime); |
457533a7 | 287 | account_user_time(tsk, utime, utimescaled); |
c6622f63 PM |
288 | } |
289 | ||
c6622f63 PM |
290 | /* |
291 | * Stuff for accounting stolen time. | |
292 | */ | |
293 | struct cpu_purr_data { | |
294 | int initialized; /* thread is running */ | |
c6622f63 PM |
295 | u64 tb; /* last TB value read */ |
296 | u64 purr; /* last PURR value read */ | |
4603ac18 | 297 | u64 spurr; /* last SPURR value read */ |
c6622f63 PM |
298 | }; |
299 | ||
df211c8a NL |
300 | /* |
301 | * Each entry in the cpu_purr_data array is manipulated only by its | |
302 | * "owner" cpu -- usually in the timer interrupt but also occasionally | |
303 | * in process context for cpu online. As long as cpus do not touch | |
304 | * each others' cpu_purr_data, disabling local interrupts is | |
305 | * sufficient to serialize accesses. | |
306 | */ | |
c6622f63 PM |
307 | static DEFINE_PER_CPU(struct cpu_purr_data, cpu_purr_data); |
308 | ||
309 | static void snapshot_tb_and_purr(void *data) | |
310 | { | |
df211c8a | 311 | unsigned long flags; |
c6622f63 PM |
312 | struct cpu_purr_data *p = &__get_cpu_var(cpu_purr_data); |
313 | ||
df211c8a | 314 | local_irq_save(flags); |
c27da339 | 315 | p->tb = get_tb_or_rtc(); |
cbcdb93d | 316 | p->purr = mfspr(SPRN_PURR); |
c6622f63 PM |
317 | wmb(); |
318 | p->initialized = 1; | |
df211c8a | 319 | local_irq_restore(flags); |
c6622f63 PM |
320 | } |
321 | ||
322 | /* | |
323 | * Called during boot when all cpus have come up. | |
324 | */ | |
325 | void snapshot_timebases(void) | |
326 | { | |
c6622f63 PM |
327 | if (!cpu_has_feature(CPU_FTR_PURR)) |
328 | return; | |
15c8b6c1 | 329 | on_each_cpu(snapshot_tb_and_purr, NULL, 1); |
c6622f63 PM |
330 | } |
331 | ||
df211c8a NL |
332 | /* |
333 | * Must be called with interrupts disabled. | |
334 | */ | |
c6622f63 PM |
335 | void calculate_steal_time(void) |
336 | { | |
cbcdb93d | 337 | u64 tb, purr; |
c6622f63 | 338 | s64 stolen; |
cbcdb93d | 339 | struct cpu_purr_data *pme; |
c6622f63 | 340 | |
8b5621f1 | 341 | pme = &__get_cpu_var(cpu_purr_data); |
c6622f63 | 342 | if (!pme->initialized) |
db3801a8 | 343 | return; /* !CPU_FTR_PURR or early in early boot */ |
c6622f63 | 344 | tb = mftb(); |
cbcdb93d SR |
345 | purr = mfspr(SPRN_PURR); |
346 | stolen = (tb - pme->tb) - (purr - pme->purr); | |
79741dd3 MS |
347 | if (stolen > 0) { |
348 | if (idle_task(smp_processor_id()) != current) | |
349 | account_steal_time(stolen); | |
350 | else | |
351 | account_idle_time(stolen); | |
352 | } | |
c6622f63 PM |
353 | pme->tb = tb; |
354 | pme->purr = purr; | |
c6622f63 PM |
355 | } |
356 | ||
4cefebb1 | 357 | #ifdef CONFIG_PPC_SPLPAR |
c6622f63 PM |
358 | /* |
359 | * Must be called before the cpu is added to the online map when | |
360 | * a cpu is being brought up at runtime. | |
361 | */ | |
362 | static void snapshot_purr(void) | |
363 | { | |
cbcdb93d | 364 | struct cpu_purr_data *pme; |
c6622f63 PM |
365 | unsigned long flags; |
366 | ||
367 | if (!cpu_has_feature(CPU_FTR_PURR)) | |
368 | return; | |
df211c8a | 369 | local_irq_save(flags); |
8b5621f1 | 370 | pme = &__get_cpu_var(cpu_purr_data); |
cbcdb93d SR |
371 | pme->tb = mftb(); |
372 | pme->purr = mfspr(SPRN_PURR); | |
c6622f63 | 373 | pme->initialized = 1; |
df211c8a | 374 | local_irq_restore(flags); |
c6622f63 PM |
375 | } |
376 | ||
377 | #endif /* CONFIG_PPC_SPLPAR */ | |
378 | ||
379 | #else /* ! CONFIG_VIRT_CPU_ACCOUNTING */ | |
380 | #define calc_cputime_factors() | |
c6622f63 PM |
381 | #define calculate_steal_time() do { } while (0) |
382 | #endif | |
383 | ||
384 | #if !(defined(CONFIG_VIRT_CPU_ACCOUNTING) && defined(CONFIG_PPC_SPLPAR)) | |
385 | #define snapshot_purr() do { } while (0) | |
386 | #endif | |
387 | ||
388 | /* | |
389 | * Called when a cpu comes up after the system has finished booting, | |
390 | * i.e. as a result of a hotplug cpu action. | |
391 | */ | |
392 | void snapshot_timebase(void) | |
393 | { | |
c27da339 | 394 | __get_cpu_var(last_jiffy) = get_tb_or_rtc(); |
c6622f63 PM |
395 | snapshot_purr(); |
396 | } | |
397 | ||
6defa38b PM |
398 | void __delay(unsigned long loops) |
399 | { | |
400 | unsigned long start; | |
401 | int diff; | |
402 | ||
403 | if (__USE_RTC()) { | |
404 | start = get_rtcl(); | |
405 | do { | |
406 | /* the RTCL register wraps at 1000000000 */ | |
407 | diff = get_rtcl() - start; | |
408 | if (diff < 0) | |
409 | diff += 1000000000; | |
410 | } while (diff < loops); | |
411 | } else { | |
412 | start = get_tbl(); | |
413 | while (get_tbl() - start < loops) | |
414 | HMT_low(); | |
415 | HMT_medium(); | |
416 | } | |
417 | } | |
418 | EXPORT_SYMBOL(__delay); | |
419 | ||
420 | void udelay(unsigned long usecs) | |
421 | { | |
422 | __delay(tb_ticks_per_usec * usecs); | |
423 | } | |
424 | EXPORT_SYMBOL(udelay); | |
425 | ||
1da177e4 LT |
426 | #ifdef CONFIG_SMP |
427 | unsigned long profile_pc(struct pt_regs *regs) | |
428 | { | |
429 | unsigned long pc = instruction_pointer(regs); | |
430 | ||
431 | if (in_lock_functions(pc)) | |
432 | return regs->link; | |
433 | ||
434 | return pc; | |
435 | } | |
436 | EXPORT_SYMBOL(profile_pc); | |
437 | #endif | |
438 | ||
439 | #ifdef CONFIG_PPC_ISERIES | |
440 | ||
441 | /* | |
442 | * This function recalibrates the timebase based on the 49-bit time-of-day | |
443 | * value in the Titan chip. The Titan is much more accurate than the value | |
444 | * returned by the service processor for the timebase frequency. | |
445 | */ | |
446 | ||
71712b45 | 447 | static int __init iSeries_tb_recal(void) |
1da177e4 LT |
448 | { |
449 | struct div_result divres; | |
450 | unsigned long titan, tb; | |
71712b45 TB |
451 | |
452 | /* Make sure we only run on iSeries */ | |
453 | if (!firmware_has_feature(FW_FEATURE_ISERIES)) | |
454 | return -ENODEV; | |
455 | ||
1da177e4 LT |
456 | tb = get_tb(); |
457 | titan = HvCallXm_loadTod(); | |
458 | if ( iSeries_recal_titan ) { | |
459 | unsigned long tb_ticks = tb - iSeries_recal_tb; | |
460 | unsigned long titan_usec = (titan - iSeries_recal_titan) >> 12; | |
461 | unsigned long new_tb_ticks_per_sec = (tb_ticks * USEC_PER_SEC)/titan_usec; | |
14ea58ad JL |
462 | unsigned long new_tb_ticks_per_jiffy = |
463 | DIV_ROUND_CLOSEST(new_tb_ticks_per_sec, HZ); | |
1da177e4 LT |
464 | long tick_diff = new_tb_ticks_per_jiffy - tb_ticks_per_jiffy; |
465 | char sign = '+'; | |
466 | /* make sure tb_ticks_per_sec and tb_ticks_per_jiffy are consistent */ | |
467 | new_tb_ticks_per_sec = new_tb_ticks_per_jiffy * HZ; | |
468 | ||
469 | if ( tick_diff < 0 ) { | |
470 | tick_diff = -tick_diff; | |
471 | sign = '-'; | |
472 | } | |
473 | if ( tick_diff ) { | |
474 | if ( tick_diff < tb_ticks_per_jiffy/25 ) { | |
475 | printk( "Titan recalibrate: new tb_ticks_per_jiffy = %lu (%c%ld)\n", | |
476 | new_tb_ticks_per_jiffy, sign, tick_diff ); | |
477 | tb_ticks_per_jiffy = new_tb_ticks_per_jiffy; | |
478 | tb_ticks_per_sec = new_tb_ticks_per_sec; | |
c6622f63 | 479 | calc_cputime_factors(); |
1da177e4 | 480 | div128_by_32( XSEC_PER_SEC, 0, tb_ticks_per_sec, &divres ); |
1da177e4 | 481 | tb_to_xs = divres.result_low; |
a7f290da BH |
482 | vdso_data->tb_ticks_per_sec = tb_ticks_per_sec; |
483 | vdso_data->tb_to_xs = tb_to_xs; | |
a42548a1 | 484 | setup_cputime_one_jiffy(); |
1da177e4 LT |
485 | } |
486 | else { | |
487 | printk( "Titan recalibrate: FAILED (difference > 4 percent)\n" | |
488 | " new tb_ticks_per_jiffy = %lu\n" | |
489 | " old tb_ticks_per_jiffy = %lu\n", | |
490 | new_tb_ticks_per_jiffy, tb_ticks_per_jiffy ); | |
491 | } | |
492 | } | |
493 | } | |
494 | iSeries_recal_titan = titan; | |
495 | iSeries_recal_tb = tb; | |
71712b45 | 496 | |
4a4cfe38 TB |
497 | /* Called here as now we know accurate values for the timebase */ |
498 | clocksource_init(); | |
71712b45 | 499 | return 0; |
1da177e4 | 500 | } |
71712b45 TB |
501 | late_initcall(iSeries_tb_recal); |
502 | ||
503 | /* Called from platform early init */ | |
504 | void __init iSeries_time_init_early(void) | |
505 | { | |
506 | iSeries_recal_tb = get_tb(); | |
507 | iSeries_recal_titan = HvCallXm_loadTod(); | |
508 | } | |
509 | #endif /* CONFIG_PPC_ISERIES */ | |
1da177e4 | 510 | |
0fe1ac48 | 511 | #ifdef CONFIG_PERF_EVENTS |
105988c0 | 512 | |
0fe1ac48 PM |
513 | /* |
514 | * 64-bit uses a byte in the PACA, 32-bit uses a per-cpu variable... | |
515 | */ | |
516 | #ifdef CONFIG_PPC64 | |
517 | static inline unsigned long test_perf_event_pending(void) | |
105988c0 | 518 | { |
0fe1ac48 PM |
519 | unsigned long x; |
520 | ||
521 | asm volatile("lbz %0,%1(13)" | |
522 | : "=r" (x) | |
523 | : "i" (offsetof(struct paca_struct, perf_event_pending))); | |
524 | return x; | |
525 | } | |
526 | ||
527 | static inline void set_perf_event_pending_flag(void) | |
528 | { | |
529 | asm volatile("stb %0,%1(13)" : : | |
530 | "r" (1), | |
531 | "i" (offsetof(struct paca_struct, perf_event_pending))); | |
532 | } | |
533 | ||
534 | static inline void clear_perf_event_pending(void) | |
535 | { | |
536 | asm volatile("stb %0,%1(13)" : : | |
537 | "r" (0), | |
538 | "i" (offsetof(struct paca_struct, perf_event_pending))); | |
105988c0 PM |
539 | } |
540 | ||
0fe1ac48 PM |
541 | #else /* 32-bit */ |
542 | ||
543 | DEFINE_PER_CPU(u8, perf_event_pending); | |
544 | ||
545 | #define set_perf_event_pending_flag() __get_cpu_var(perf_event_pending) = 1 | |
cdd6c482 IM |
546 | #define test_perf_event_pending() __get_cpu_var(perf_event_pending) |
547 | #define clear_perf_event_pending() __get_cpu_var(perf_event_pending) = 0 | |
105988c0 | 548 | |
0fe1ac48 PM |
549 | #endif /* 32 vs 64 bit */ |
550 | ||
551 | void set_perf_event_pending(void) | |
552 | { | |
553 | preempt_disable(); | |
554 | set_perf_event_pending_flag(); | |
555 | set_dec(1); | |
556 | preempt_enable(); | |
557 | } | |
558 | ||
559 | #else /* CONFIG_PERF_EVENTS */ | |
105988c0 | 560 | |
cdd6c482 IM |
561 | #define test_perf_event_pending() 0 |
562 | #define clear_perf_event_pending() | |
105988c0 | 563 | |
0fe1ac48 | 564 | #endif /* CONFIG_PERF_EVENTS */ |
105988c0 | 565 | |
1da177e4 LT |
566 | /* |
567 | * For iSeries shared processors, we have to let the hypervisor | |
568 | * set the hardware decrementer. We set a virtual decrementer | |
569 | * in the lppaca and call the hypervisor if the virtual | |
570 | * decrementer is less than the current value in the hardware | |
571 | * decrementer. (almost always the new decrementer value will | |
572 | * be greater than the current hardware decementer so the hypervisor | |
573 | * call will not be needed) | |
574 | */ | |
575 | ||
1da177e4 LT |
576 | /* |
577 | * timer_interrupt - gets called when the decrementer overflows, | |
578 | * with interrupts disabled. | |
579 | */ | |
c7aeffc4 | 580 | void timer_interrupt(struct pt_regs * regs) |
1da177e4 | 581 | { |
7d12e780 | 582 | struct pt_regs *old_regs; |
6e6b44e8 MM |
583 | struct decrementer_clock *decrementer = &__get_cpu_var(decrementers); |
584 | struct clock_event_device *evt = &decrementer->event; | |
d968014b | 585 | u64 now; |
d831d0b8 | 586 | |
6795b85c AB |
587 | trace_timer_interrupt_entry(regs); |
588 | ||
89713ed1 AB |
589 | __get_cpu_var(irq_stat).timer_irqs++; |
590 | ||
d831d0b8 TB |
591 | /* Ensure a positive value is written to the decrementer, or else |
592 | * some CPUs will continuue to take decrementer exceptions */ | |
593 | set_dec(DECREMENTER_MAX); | |
f2783c15 PM |
594 | |
595 | #ifdef CONFIG_PPC32 | |
596 | if (atomic_read(&ppc_n_lost_interrupts) != 0) | |
597 | do_IRQ(regs); | |
598 | #endif | |
1da177e4 | 599 | |
d968014b | 600 | now = get_tb_or_rtc(); |
6e6b44e8 | 601 | if (now < decrementer->next_tb) { |
d968014b | 602 | /* not time for this event yet */ |
6e6b44e8 | 603 | now = decrementer->next_tb - now; |
d968014b | 604 | if (now <= DECREMENTER_MAX) |
43875cc0 | 605 | set_dec((int)now); |
6795b85c | 606 | trace_timer_interrupt_exit(regs); |
d968014b PM |
607 | return; |
608 | } | |
7d12e780 | 609 | old_regs = set_irq_regs(regs); |
1da177e4 LT |
610 | irq_enter(); |
611 | ||
c6622f63 | 612 | calculate_steal_time(); |
1da177e4 | 613 | |
0fe1ac48 PM |
614 | if (test_perf_event_pending()) { |
615 | clear_perf_event_pending(); | |
616 | perf_event_do_pending(); | |
617 | } | |
618 | ||
f2783c15 | 619 | #ifdef CONFIG_PPC_ISERIES |
501b6d29 SR |
620 | if (firmware_has_feature(FW_FEATURE_ISERIES)) |
621 | get_lppaca()->int_dword.fields.decr_int = 0; | |
f2783c15 PM |
622 | #endif |
623 | ||
d831d0b8 TB |
624 | if (evt->event_handler) |
625 | evt->event_handler(evt); | |
1da177e4 LT |
626 | |
627 | #ifdef CONFIG_PPC_ISERIES | |
501b6d29 | 628 | if (firmware_has_feature(FW_FEATURE_ISERIES) && hvlpevent_is_pending()) |
35a84c2f | 629 | process_hvlpevents(); |
1da177e4 LT |
630 | #endif |
631 | ||
f2783c15 | 632 | #ifdef CONFIG_PPC64 |
8d15a3e5 | 633 | /* collect purr register values often, for accurate calculations */ |
1ababe11 | 634 | if (firmware_has_feature(FW_FEATURE_SPLPAR)) { |
1da177e4 LT |
635 | struct cpu_usage *cu = &__get_cpu_var(cpu_usage_array); |
636 | cu->current_tb = mfspr(SPRN_PURR); | |
637 | } | |
f2783c15 | 638 | #endif |
1da177e4 LT |
639 | |
640 | irq_exit(); | |
7d12e780 | 641 | set_irq_regs(old_regs); |
6795b85c AB |
642 | |
643 | trace_timer_interrupt_exit(regs); | |
1da177e4 LT |
644 | } |
645 | ||
f2783c15 PM |
646 | void wakeup_decrementer(void) |
647 | { | |
092b8f34 | 648 | unsigned long ticks; |
f2783c15 | 649 | |
f2783c15 | 650 | /* |
092b8f34 PM |
651 | * The timebase gets saved on sleep and restored on wakeup, |
652 | * so all we need to do is to reset the decrementer. | |
f2783c15 | 653 | */ |
092b8f34 PM |
654 | ticks = tb_ticks_since(__get_cpu_var(last_jiffy)); |
655 | if (ticks < tb_ticks_per_jiffy) | |
656 | ticks = tb_ticks_per_jiffy - ticks; | |
657 | else | |
658 | ticks = 1; | |
659 | set_dec(ticks); | |
f2783c15 PM |
660 | } |
661 | ||
7ac5dde9 SW |
662 | #ifdef CONFIG_SUSPEND |
663 | void generic_suspend_disable_irqs(void) | |
664 | { | |
665 | preempt_disable(); | |
666 | ||
667 | /* Disable the decrementer, so that it doesn't interfere | |
668 | * with suspending. | |
669 | */ | |
670 | ||
671 | set_dec(0x7fffffff); | |
672 | local_irq_disable(); | |
673 | set_dec(0x7fffffff); | |
674 | } | |
675 | ||
676 | void generic_suspend_enable_irqs(void) | |
677 | { | |
678 | wakeup_decrementer(); | |
679 | ||
680 | local_irq_enable(); | |
681 | preempt_enable(); | |
682 | } | |
683 | ||
684 | /* Overrides the weak version in kernel/power/main.c */ | |
685 | void arch_suspend_disable_irqs(void) | |
686 | { | |
687 | if (ppc_md.suspend_disable_irqs) | |
688 | ppc_md.suspend_disable_irqs(); | |
689 | generic_suspend_disable_irqs(); | |
690 | } | |
691 | ||
692 | /* Overrides the weak version in kernel/power/main.c */ | |
693 | void arch_suspend_enable_irqs(void) | |
694 | { | |
695 | generic_suspend_enable_irqs(); | |
696 | if (ppc_md.suspend_enable_irqs) | |
697 | ppc_md.suspend_enable_irqs(); | |
698 | } | |
699 | #endif | |
700 | ||
a5b518ed | 701 | #ifdef CONFIG_SMP |
f2783c15 PM |
702 | void __init smp_space_timers(unsigned int max_cpus) |
703 | { | |
704 | int i; | |
eb36c288 | 705 | u64 previous_tb = per_cpu(last_jiffy, boot_cpuid); |
f2783c15 | 706 | |
cbe62e2b PM |
707 | /* make sure tb > per_cpu(last_jiffy, cpu) for all cpus always */ |
708 | previous_tb -= tb_ticks_per_jiffy; | |
e147ec8f | 709 | |
0e551954 | 710 | for_each_possible_cpu(i) { |
c6622f63 PM |
711 | if (i == boot_cpuid) |
712 | continue; | |
e147ec8f | 713 | per_cpu(last_jiffy, i) = previous_tb; |
f2783c15 PM |
714 | } |
715 | } | |
716 | #endif | |
717 | ||
1da177e4 LT |
718 | /* |
719 | * Scheduler clock - returns current time in nanosec units. | |
720 | * | |
721 | * Note: mulhdu(a, b) (multiply high double unsigned) returns | |
722 | * the high 64 bits of a * b, i.e. (a * b) >> 64, where a and b | |
723 | * are 64-bit unsigned numbers. | |
724 | */ | |
725 | unsigned long long sched_clock(void) | |
726 | { | |
96c44507 PM |
727 | if (__USE_RTC()) |
728 | return get_rtc(); | |
fc9069fe | 729 | return mulhdu(get_tb() - boot_tb, tb_to_ns_scale) << tb_to_ns_shift; |
1da177e4 LT |
730 | } |
731 | ||
0bb474a4 | 732 | static int __init get_freq(char *name, int cells, unsigned long *val) |
10f7e7c1 AB |
733 | { |
734 | struct device_node *cpu; | |
a7f67bdf | 735 | const unsigned int *fp; |
0bb474a4 | 736 | int found = 0; |
10f7e7c1 | 737 | |
0bb474a4 | 738 | /* The cpu node should have timebase and clock frequency properties */ |
10f7e7c1 AB |
739 | cpu = of_find_node_by_type(NULL, "cpu"); |
740 | ||
d8a8188d | 741 | if (cpu) { |
e2eb6392 | 742 | fp = of_get_property(cpu, name, NULL); |
d8a8188d | 743 | if (fp) { |
0bb474a4 | 744 | found = 1; |
a4dc7ff0 | 745 | *val = of_read_ulong(fp, cells); |
10f7e7c1 | 746 | } |
0bb474a4 AB |
747 | |
748 | of_node_put(cpu); | |
10f7e7c1 | 749 | } |
0bb474a4 AB |
750 | |
751 | return found; | |
752 | } | |
753 | ||
77c0a700 BH |
754 | /* should become __cpuinit when secondary_cpu_time_init also is */ |
755 | void start_cpu_decrementer(void) | |
756 | { | |
757 | #if defined(CONFIG_BOOKE) || defined(CONFIG_40x) | |
758 | /* Clear any pending timer interrupts */ | |
759 | mtspr(SPRN_TSR, TSR_ENW | TSR_WIS | TSR_DIS | TSR_FIS); | |
760 | ||
761 | /* Enable decrementer interrupt */ | |
762 | mtspr(SPRN_TCR, TCR_DIE); | |
763 | #endif /* defined(CONFIG_BOOKE) || defined(CONFIG_40x) */ | |
764 | } | |
765 | ||
0bb474a4 AB |
766 | void __init generic_calibrate_decr(void) |
767 | { | |
768 | ppc_tb_freq = DEFAULT_TB_FREQ; /* hardcoded default */ | |
769 | ||
770 | if (!get_freq("ibm,extended-timebase-frequency", 2, &ppc_tb_freq) && | |
771 | !get_freq("timebase-frequency", 1, &ppc_tb_freq)) { | |
772 | ||
10f7e7c1 AB |
773 | printk(KERN_ERR "WARNING: Estimating decrementer frequency " |
774 | "(not found)\n"); | |
0bb474a4 | 775 | } |
10f7e7c1 | 776 | |
0bb474a4 AB |
777 | ppc_proc_freq = DEFAULT_PROC_FREQ; /* hardcoded default */ |
778 | ||
779 | if (!get_freq("ibm,extended-clock-frequency", 2, &ppc_proc_freq) && | |
780 | !get_freq("clock-frequency", 1, &ppc_proc_freq)) { | |
781 | ||
782 | printk(KERN_ERR "WARNING: Estimating processor frequency " | |
783 | "(not found)\n"); | |
10f7e7c1 | 784 | } |
10f7e7c1 | 785 | } |
10f7e7c1 | 786 | |
aa3be5f3 | 787 | int update_persistent_clock(struct timespec now) |
f2783c15 PM |
788 | { |
789 | struct rtc_time tm; | |
790 | ||
aa3be5f3 TB |
791 | if (!ppc_md.set_rtc_time) |
792 | return 0; | |
793 | ||
794 | to_tm(now.tv_sec + 1 + timezone_offset, &tm); | |
795 | tm.tm_year -= 1900; | |
796 | tm.tm_mon -= 1; | |
797 | ||
798 | return ppc_md.set_rtc_time(&tm); | |
799 | } | |
800 | ||
978d7eb3 | 801 | static void __read_persistent_clock(struct timespec *ts) |
aa3be5f3 TB |
802 | { |
803 | struct rtc_time tm; | |
804 | static int first = 1; | |
805 | ||
d90246cd | 806 | ts->tv_nsec = 0; |
aa3be5f3 TB |
807 | /* XXX this is a litle fragile but will work okay in the short term */ |
808 | if (first) { | |
809 | first = 0; | |
810 | if (ppc_md.time_init) | |
811 | timezone_offset = ppc_md.time_init(); | |
812 | ||
813 | /* get_boot_time() isn't guaranteed to be safe to call late */ | |
d90246cd MS |
814 | if (ppc_md.get_boot_time) { |
815 | ts->tv_sec = ppc_md.get_boot_time() - timezone_offset; | |
816 | return; | |
817 | } | |
818 | } | |
819 | if (!ppc_md.get_rtc_time) { | |
820 | ts->tv_sec = 0; | |
821 | return; | |
aa3be5f3 | 822 | } |
f2783c15 | 823 | ppc_md.get_rtc_time(&tm); |
978d7eb3 | 824 | |
d4f587c6 MS |
825 | ts->tv_sec = mktime(tm.tm_year+1900, tm.tm_mon+1, tm.tm_mday, |
826 | tm.tm_hour, tm.tm_min, tm.tm_sec); | |
f2783c15 PM |
827 | } |
828 | ||
978d7eb3 BH |
829 | void read_persistent_clock(struct timespec *ts) |
830 | { | |
831 | __read_persistent_clock(ts); | |
832 | ||
833 | /* Sanitize it in case real time clock is set below EPOCH */ | |
834 | if (ts->tv_sec < 0) { | |
835 | ts->tv_sec = 0; | |
836 | ts->tv_nsec = 0; | |
837 | } | |
838 | ||
839 | } | |
840 | ||
4a4cfe38 | 841 | /* clocksource code */ |
8e19608e | 842 | static cycle_t rtc_read(struct clocksource *cs) |
4a4cfe38 TB |
843 | { |
844 | return (cycle_t)get_rtc(); | |
845 | } | |
846 | ||
8e19608e | 847 | static cycle_t timebase_read(struct clocksource *cs) |
4a4cfe38 TB |
848 | { |
849 | return (cycle_t)get_tb(); | |
850 | } | |
851 | ||
0696b711 LM |
852 | void update_vsyscall(struct timespec *wall_time, struct clocksource *clock, |
853 | u32 mult) | |
4a4cfe38 | 854 | { |
b0797b60 | 855 | u64 new_tb_to_xs, new_stamp_xsec; |
4a4cfe38 TB |
856 | |
857 | if (clock != &clocksource_timebase) | |
858 | return; | |
859 | ||
860 | /* Make userspace gettimeofday spin until we're done. */ | |
861 | ++vdso_data->tb_update_count; | |
862 | smp_mb(); | |
863 | ||
864 | /* XXX this assumes clock->shift == 22 */ | |
865 | /* 4611686018 ~= 2^(20+64-22) / 1e9 */ | |
b0797b60 | 866 | new_tb_to_xs = (u64) mult * 4611686018ULL; |
06d518e3 | 867 | new_stamp_xsec = (u64) wall_time->tv_nsec * XSEC_PER_SEC; |
b0797b60 | 868 | do_div(new_stamp_xsec, 1000000000); |
06d518e3 | 869 | new_stamp_xsec += (u64) wall_time->tv_sec * XSEC_PER_SEC; |
b0797b60 JS |
870 | |
871 | /* | |
872 | * tb_update_count is used to allow the userspace gettimeofday code | |
873 | * to assure itself that it sees a consistent view of the tb_to_xs and | |
874 | * stamp_xsec variables. It reads the tb_update_count, then reads | |
875 | * tb_to_xs and stamp_xsec and then reads tb_update_count again. If | |
876 | * the two values of tb_update_count match and are even then the | |
877 | * tb_to_xs and stamp_xsec values are consistent. If not, then it | |
878 | * loops back and reads them again until this criteria is met. | |
879 | * We expect the caller to have done the first increment of | |
880 | * vdso_data->tb_update_count already. | |
881 | */ | |
882 | vdso_data->tb_orig_stamp = clock->cycle_last; | |
883 | vdso_data->stamp_xsec = new_stamp_xsec; | |
884 | vdso_data->tb_to_xs = new_tb_to_xs; | |
885 | vdso_data->wtom_clock_sec = wall_to_monotonic.tv_sec; | |
886 | vdso_data->wtom_clock_nsec = wall_to_monotonic.tv_nsec; | |
06d518e3 | 887 | vdso_data->stamp_xtime = *wall_time; |
b0797b60 JS |
888 | smp_wmb(); |
889 | ++(vdso_data->tb_update_count); | |
4a4cfe38 TB |
890 | } |
891 | ||
892 | void update_vsyscall_tz(void) | |
893 | { | |
894 | /* Make userspace gettimeofday spin until we're done. */ | |
895 | ++vdso_data->tb_update_count; | |
896 | smp_mb(); | |
897 | vdso_data->tz_minuteswest = sys_tz.tz_minuteswest; | |
898 | vdso_data->tz_dsttime = sys_tz.tz_dsttime; | |
899 | smp_mb(); | |
900 | ++vdso_data->tb_update_count; | |
901 | } | |
902 | ||
1c21a293 | 903 | static void __init clocksource_init(void) |
4a4cfe38 TB |
904 | { |
905 | struct clocksource *clock; | |
906 | ||
907 | if (__USE_RTC()) | |
908 | clock = &clocksource_rtc; | |
909 | else | |
910 | clock = &clocksource_timebase; | |
911 | ||
912 | clock->mult = clocksource_hz2mult(tb_ticks_per_sec, clock->shift); | |
913 | ||
914 | if (clocksource_register(clock)) { | |
915 | printk(KERN_ERR "clocksource: %s is already registered\n", | |
916 | clock->name); | |
917 | return; | |
918 | } | |
919 | ||
920 | printk(KERN_INFO "clocksource: %s mult[%x] shift[%d] registered\n", | |
921 | clock->name, clock->mult, clock->shift); | |
922 | } | |
923 | ||
d831d0b8 TB |
924 | static int decrementer_set_next_event(unsigned long evt, |
925 | struct clock_event_device *dev) | |
926 | { | |
6e6b44e8 | 927 | __get_cpu_var(decrementers).next_tb = get_tb_or_rtc() + evt; |
d831d0b8 TB |
928 | set_dec(evt); |
929 | return 0; | |
930 | } | |
931 | ||
932 | static void decrementer_set_mode(enum clock_event_mode mode, | |
933 | struct clock_event_device *dev) | |
934 | { | |
935 | if (mode != CLOCK_EVT_MODE_ONESHOT) | |
936 | decrementer_set_next_event(DECREMENTER_MAX, dev); | |
937 | } | |
938 | ||
3e7b4843 SR |
939 | static inline uint64_t div_sc64(unsigned long ticks, unsigned long nsec, |
940 | int shift) | |
941 | { | |
942 | uint64_t tmp = ((uint64_t)ticks) << shift; | |
943 | ||
944 | do_div(tmp, nsec); | |
945 | return tmp; | |
946 | } | |
947 | ||
8d165db1 AB |
948 | static void __init setup_clockevent_multiplier(unsigned long hz) |
949 | { | |
950 | u64 mult, shift = 32; | |
951 | ||
952 | while (1) { | |
3e7b4843 | 953 | mult = div_sc64(hz, NSEC_PER_SEC, shift); |
8d165db1 AB |
954 | if (mult && (mult >> 32UL) == 0UL) |
955 | break; | |
956 | ||
957 | shift--; | |
958 | } | |
959 | ||
960 | decrementer_clockevent.shift = shift; | |
961 | decrementer_clockevent.mult = mult; | |
962 | } | |
963 | ||
d831d0b8 TB |
964 | static void register_decrementer_clockevent(int cpu) |
965 | { | |
6e6b44e8 | 966 | struct clock_event_device *dec = &per_cpu(decrementers, cpu).event; |
d831d0b8 TB |
967 | |
968 | *dec = decrementer_clockevent; | |
320ab2b0 | 969 | dec->cpumask = cpumask_of(cpu); |
d831d0b8 | 970 | |
b919ee82 AB |
971 | printk_once(KERN_DEBUG "clockevent: %s mult[%x] shift[%d] cpu[%d]\n", |
972 | dec->name, dec->mult, dec->shift, cpu); | |
d831d0b8 TB |
973 | |
974 | clockevents_register_device(dec); | |
975 | } | |
976 | ||
c481887f | 977 | static void __init init_decrementer_clockevent(void) |
d831d0b8 TB |
978 | { |
979 | int cpu = smp_processor_id(); | |
980 | ||
8d165db1 | 981 | setup_clockevent_multiplier(ppc_tb_freq); |
d831d0b8 TB |
982 | decrementer_clockevent.max_delta_ns = |
983 | clockevent_delta2ns(DECREMENTER_MAX, &decrementer_clockevent); | |
43875cc0 PM |
984 | decrementer_clockevent.min_delta_ns = |
985 | clockevent_delta2ns(2, &decrementer_clockevent); | |
d831d0b8 TB |
986 | |
987 | register_decrementer_clockevent(cpu); | |
988 | } | |
989 | ||
990 | void secondary_cpu_time_init(void) | |
991 | { | |
77c0a700 BH |
992 | /* Start the decrementer on CPUs that have manual control |
993 | * such as BookE | |
994 | */ | |
995 | start_cpu_decrementer(); | |
996 | ||
d831d0b8 TB |
997 | /* FIME: Should make unrelatred change to move snapshot_timebase |
998 | * call here ! */ | |
999 | register_decrementer_clockevent(smp_processor_id()); | |
1000 | } | |
1001 | ||
f2783c15 | 1002 | /* This function is only called on the boot processor */ |
1da177e4 LT |
1003 | void __init time_init(void) |
1004 | { | |
1da177e4 | 1005 | unsigned long flags; |
1da177e4 | 1006 | struct div_result res; |
092b8f34 | 1007 | u64 scale, x; |
f2783c15 PM |
1008 | unsigned shift; |
1009 | ||
96c44507 PM |
1010 | if (__USE_RTC()) { |
1011 | /* 601 processor: dec counts down by 128 every 128ns */ | |
1012 | ppc_tb_freq = 1000000000; | |
eb36c288 | 1013 | tb_last_jiffy = get_rtcl(); |
96c44507 PM |
1014 | } else { |
1015 | /* Normal PowerPC with timebase register */ | |
1016 | ppc_md.calibrate_decr(); | |
224ad80a | 1017 | printk(KERN_DEBUG "time_init: decrementer frequency = %lu.%.6lu MHz\n", |
96c44507 | 1018 | ppc_tb_freq / 1000000, ppc_tb_freq % 1000000); |
224ad80a | 1019 | printk(KERN_DEBUG "time_init: processor frequency = %lu.%.6lu MHz\n", |
96c44507 | 1020 | ppc_proc_freq / 1000000, ppc_proc_freq % 1000000); |
eb36c288 | 1021 | tb_last_jiffy = get_tb(); |
96c44507 | 1022 | } |
374e99d4 PM |
1023 | |
1024 | tb_ticks_per_jiffy = ppc_tb_freq / HZ; | |
092b8f34 | 1025 | tb_ticks_per_sec = ppc_tb_freq; |
374e99d4 PM |
1026 | tb_ticks_per_usec = ppc_tb_freq / 1000000; |
1027 | tb_to_us = mulhwu_scale_factor(ppc_tb_freq, 1000000); | |
c6622f63 | 1028 | calc_cputime_factors(); |
a42548a1 | 1029 | setup_cputime_one_jiffy(); |
092b8f34 PM |
1030 | |
1031 | /* | |
1032 | * Calculate the length of each tick in ns. It will not be | |
1033 | * exactly 1e9/HZ unless ppc_tb_freq is divisible by HZ. | |
1034 | * We compute 1e9 * tb_ticks_per_jiffy / ppc_tb_freq, | |
1035 | * rounded up. | |
1036 | */ | |
1037 | x = (u64) NSEC_PER_SEC * tb_ticks_per_jiffy + ppc_tb_freq - 1; | |
1038 | do_div(x, ppc_tb_freq); | |
1039 | tick_nsec = x; | |
1040 | last_tick_len = x << TICKLEN_SCALE; | |
1041 | ||
1042 | /* | |
1043 | * Compute ticklen_to_xs, which is a factor which gets multiplied | |
1044 | * by (last_tick_len << TICKLEN_SHIFT) to get a tb_to_xs value. | |
1045 | * It is computed as: | |
1046 | * ticklen_to_xs = 2^N / (tb_ticks_per_jiffy * 1e9) | |
1047 | * where N = 64 + 20 - TICKLEN_SCALE - TICKLEN_SHIFT | |
0a45d449 PM |
1048 | * which turns out to be N = 51 - SHIFT_HZ. |
1049 | * This gives the result as a 0.64 fixed-point fraction. | |
1050 | * That value is reduced by an offset amounting to 1 xsec per | |
1051 | * 2^31 timebase ticks to avoid problems with time going backwards | |
1052 | * by 1 xsec when we do timer_recalc_offset due to losing the | |
1053 | * fractional xsec. That offset is equal to ppc_tb_freq/2^51 | |
1054 | * since there are 2^20 xsec in a second. | |
092b8f34 | 1055 | */ |
0a45d449 PM |
1056 | div128_by_32((1ULL << 51) - ppc_tb_freq, 0, |
1057 | tb_ticks_per_jiffy << SHIFT_HZ, &res); | |
092b8f34 PM |
1058 | div128_by_32(res.result_high, res.result_low, NSEC_PER_SEC, &res); |
1059 | ticklen_to_xs = res.result_low; | |
1060 | ||
1061 | /* Compute tb_to_xs from tick_nsec */ | |
1062 | tb_to_xs = mulhdu(last_tick_len << TICKLEN_SHIFT, ticklen_to_xs); | |
374e99d4 | 1063 | |
1da177e4 LT |
1064 | /* |
1065 | * Compute scale factor for sched_clock. | |
1066 | * The calibrate_decr() function has set tb_ticks_per_sec, | |
1067 | * which is the timebase frequency. | |
1068 | * We compute 1e9 * 2^64 / tb_ticks_per_sec and interpret | |
1069 | * the 128-bit result as a 64.64 fixed-point number. | |
1070 | * We then shift that number right until it is less than 1.0, | |
1071 | * giving us the scale factor and shift count to use in | |
1072 | * sched_clock(). | |
1073 | */ | |
1074 | div128_by_32(1000000000, 0, tb_ticks_per_sec, &res); | |
1075 | scale = res.result_low; | |
1076 | for (shift = 0; res.result_high != 0; ++shift) { | |
1077 | scale = (scale >> 1) | (res.result_high << 63); | |
1078 | res.result_high >>= 1; | |
1079 | } | |
1080 | tb_to_ns_scale = scale; | |
1081 | tb_to_ns_shift = shift; | |
fc9069fe | 1082 | /* Save the current timebase to pretty up CONFIG_PRINTK_TIME */ |
c27da339 | 1083 | boot_tb = get_tb_or_rtc(); |
1da177e4 | 1084 | |
1da177e4 | 1085 | write_seqlock_irqsave(&xtime_lock, flags); |
092b8f34 PM |
1086 | |
1087 | /* If platform provided a timezone (pmac), we correct the time */ | |
1088 | if (timezone_offset) { | |
1089 | sys_tz.tz_minuteswest = -timezone_offset / 60; | |
1090 | sys_tz.tz_dsttime = 0; | |
092b8f34 PM |
1091 | } |
1092 | ||
a7f290da BH |
1093 | vdso_data->tb_orig_stamp = tb_last_jiffy; |
1094 | vdso_data->tb_update_count = 0; | |
1095 | vdso_data->tb_ticks_per_sec = tb_ticks_per_sec; | |
06d518e3 | 1096 | vdso_data->stamp_xsec = (u64) get_seconds() * XSEC_PER_SEC; |
a7f290da | 1097 | vdso_data->tb_to_xs = tb_to_xs; |
1da177e4 | 1098 | |
1da177e4 LT |
1099 | write_sequnlock_irqrestore(&xtime_lock, flags); |
1100 | ||
77c0a700 BH |
1101 | /* Start the decrementer on CPUs that have manual control |
1102 | * such as BookE | |
1103 | */ | |
1104 | start_cpu_decrementer(); | |
1105 | ||
4a4cfe38 TB |
1106 | /* Register the clocksource, if we're not running on iSeries */ |
1107 | if (!firmware_has_feature(FW_FEATURE_ISERIES)) | |
1108 | clocksource_init(); | |
1109 | ||
d831d0b8 | 1110 | init_decrementer_clockevent(); |
1da177e4 LT |
1111 | } |
1112 | ||
1da177e4 | 1113 | |
1da177e4 LT |
1114 | #define FEBRUARY 2 |
1115 | #define STARTOFTIME 1970 | |
1116 | #define SECDAY 86400L | |
1117 | #define SECYR (SECDAY * 365) | |
f2783c15 PM |
1118 | #define leapyear(year) ((year) % 4 == 0 && \ |
1119 | ((year) % 100 != 0 || (year) % 400 == 0)) | |
1da177e4 LT |
1120 | #define days_in_year(a) (leapyear(a) ? 366 : 365) |
1121 | #define days_in_month(a) (month_days[(a) - 1]) | |
1122 | ||
1123 | static int month_days[12] = { | |
1124 | 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 | |
1125 | }; | |
1126 | ||
1127 | /* | |
1128 | * This only works for the Gregorian calendar - i.e. after 1752 (in the UK) | |
1129 | */ | |
1130 | void GregorianDay(struct rtc_time * tm) | |
1131 | { | |
1132 | int leapsToDate; | |
1133 | int lastYear; | |
1134 | int day; | |
1135 | int MonthOffset[] = { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 }; | |
1136 | ||
f2783c15 | 1137 | lastYear = tm->tm_year - 1; |
1da177e4 LT |
1138 | |
1139 | /* | |
1140 | * Number of leap corrections to apply up to end of last year | |
1141 | */ | |
f2783c15 | 1142 | leapsToDate = lastYear / 4 - lastYear / 100 + lastYear / 400; |
1da177e4 LT |
1143 | |
1144 | /* | |
1145 | * This year is a leap year if it is divisible by 4 except when it is | |
1146 | * divisible by 100 unless it is divisible by 400 | |
1147 | * | |
f2783c15 | 1148 | * e.g. 1904 was a leap year, 1900 was not, 1996 is, and 2000 was |
1da177e4 | 1149 | */ |
f2783c15 | 1150 | day = tm->tm_mon > 2 && leapyear(tm->tm_year); |
1da177e4 LT |
1151 | |
1152 | day += lastYear*365 + leapsToDate + MonthOffset[tm->tm_mon-1] + | |
1153 | tm->tm_mday; | |
1154 | ||
f2783c15 | 1155 | tm->tm_wday = day % 7; |
1da177e4 LT |
1156 | } |
1157 | ||
1158 | void to_tm(int tim, struct rtc_time * tm) | |
1159 | { | |
1160 | register int i; | |
1161 | register long hms, day; | |
1162 | ||
1163 | day = tim / SECDAY; | |
1164 | hms = tim % SECDAY; | |
1165 | ||
1166 | /* Hours, minutes, seconds are easy */ | |
1167 | tm->tm_hour = hms / 3600; | |
1168 | tm->tm_min = (hms % 3600) / 60; | |
1169 | tm->tm_sec = (hms % 3600) % 60; | |
1170 | ||
1171 | /* Number of years in days */ | |
1172 | for (i = STARTOFTIME; day >= days_in_year(i); i++) | |
1173 | day -= days_in_year(i); | |
1174 | tm->tm_year = i; | |
1175 | ||
1176 | /* Number of months in days left */ | |
1177 | if (leapyear(tm->tm_year)) | |
1178 | days_in_month(FEBRUARY) = 29; | |
1179 | for (i = 1; day >= days_in_month(i); i++) | |
1180 | day -= days_in_month(i); | |
1181 | days_in_month(FEBRUARY) = 28; | |
1182 | tm->tm_mon = i; | |
1183 | ||
1184 | /* Days are what is left over (+1) from all that. */ | |
1185 | tm->tm_mday = day + 1; | |
1186 | ||
1187 | /* | |
1188 | * Determine the day of week | |
1189 | */ | |
1190 | GregorianDay(tm); | |
1191 | } | |
1192 | ||
1193 | /* Auxiliary function to compute scaling factors */ | |
1194 | /* Actually the choice of a timebase running at 1/4 the of the bus | |
1195 | * frequency giving resolution of a few tens of nanoseconds is quite nice. | |
1196 | * It makes this computation very precise (27-28 bits typically) which | |
1197 | * is optimistic considering the stability of most processor clock | |
1198 | * oscillators and the precision with which the timebase frequency | |
1199 | * is measured but does not harm. | |
1200 | */ | |
f2783c15 PM |
1201 | unsigned mulhwu_scale_factor(unsigned inscale, unsigned outscale) |
1202 | { | |
1da177e4 LT |
1203 | unsigned mlt=0, tmp, err; |
1204 | /* No concern for performance, it's done once: use a stupid | |
1205 | * but safe and compact method to find the multiplier. | |
1206 | */ | |
1207 | ||
1208 | for (tmp = 1U<<31; tmp != 0; tmp >>= 1) { | |
f2783c15 PM |
1209 | if (mulhwu(inscale, mlt|tmp) < outscale) |
1210 | mlt |= tmp; | |
1da177e4 LT |
1211 | } |
1212 | ||
1213 | /* We might still be off by 1 for the best approximation. | |
1214 | * A side effect of this is that if outscale is too large | |
1215 | * the returned value will be zero. | |
1216 | * Many corner cases have been checked and seem to work, | |
1217 | * some might have been forgotten in the test however. | |
1218 | */ | |
1219 | ||
f2783c15 PM |
1220 | err = inscale * (mlt+1); |
1221 | if (err <= inscale/2) | |
1222 | mlt++; | |
1da177e4 | 1223 | return mlt; |
f2783c15 | 1224 | } |
1da177e4 LT |
1225 | |
1226 | /* | |
1227 | * Divide a 128-bit dividend by a 32-bit divisor, leaving a 128 bit | |
1228 | * result. | |
1229 | */ | |
f2783c15 PM |
1230 | void div128_by_32(u64 dividend_high, u64 dividend_low, |
1231 | unsigned divisor, struct div_result *dr) | |
1da177e4 | 1232 | { |
f2783c15 PM |
1233 | unsigned long a, b, c, d; |
1234 | unsigned long w, x, y, z; | |
1235 | u64 ra, rb, rc; | |
1da177e4 LT |
1236 | |
1237 | a = dividend_high >> 32; | |
1238 | b = dividend_high & 0xffffffff; | |
1239 | c = dividend_low >> 32; | |
1240 | d = dividend_low & 0xffffffff; | |
1241 | ||
f2783c15 PM |
1242 | w = a / divisor; |
1243 | ra = ((u64)(a - (w * divisor)) << 32) + b; | |
1244 | ||
f2783c15 PM |
1245 | rb = ((u64) do_div(ra, divisor) << 32) + c; |
1246 | x = ra; | |
1da177e4 | 1247 | |
f2783c15 PM |
1248 | rc = ((u64) do_div(rb, divisor) << 32) + d; |
1249 | y = rb; | |
1250 | ||
1251 | do_div(rc, divisor); | |
1252 | z = rc; | |
1da177e4 | 1253 | |
f2783c15 PM |
1254 | dr->result_high = ((u64)w << 32) + x; |
1255 | dr->result_low = ((u64)y << 32) + z; | |
1da177e4 LT |
1256 | |
1257 | } | |
bcd68a70 | 1258 | |
177996e6 BH |
1259 | /* We don't need to calibrate delay, we use the CPU timebase for that */ |
1260 | void calibrate_delay(void) | |
1261 | { | |
1262 | /* Some generic code (such as spinlock debug) use loops_per_jiffy | |
1263 | * as the number of __delay(1) in a jiffy, so make it so | |
1264 | */ | |
1265 | loops_per_jiffy = tb_ticks_per_jiffy; | |
1266 | } | |
1267 | ||
bcd68a70 GU |
1268 | static int __init rtc_init(void) |
1269 | { | |
1270 | struct platform_device *pdev; | |
1271 | ||
1272 | if (!ppc_md.get_rtc_time) | |
1273 | return -ENODEV; | |
1274 | ||
1275 | pdev = platform_device_register_simple("rtc-generic", -1, NULL, 0); | |
1276 | if (IS_ERR(pdev)) | |
1277 | return PTR_ERR(pdev); | |
1278 | ||
1279 | return 0; | |
1280 | } | |
1281 | ||
1282 | module_init(rtc_init); |