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Commit | Line | Data |
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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 | |
f5339277 | 20 | * measurement at boot time. |
1da177e4 LT |
21 | * - for astronomical applications: add a new function to get |
22 | * non ambiguous timestamps even around leap seconds. This needs | |
23 | * a new timestamp format and a good name. | |
24 | * | |
25 | * 1997-09-10 Updated NTP code according to technical memorandum Jan '96 | |
26 | * "A Kernel Model for Precision Timekeeping" by Dave Mills | |
27 | * | |
28 | * This program is free software; you can redistribute it and/or | |
29 | * modify it under the terms of the GNU General Public License | |
30 | * as published by the Free Software Foundation; either version | |
31 | * 2 of the License, or (at your option) any later version. | |
32 | */ | |
33 | ||
1da177e4 | 34 | #include <linux/errno.h> |
4b16f8e2 | 35 | #include <linux/export.h> |
1da177e4 LT |
36 | #include <linux/sched.h> |
37 | #include <linux/kernel.h> | |
38 | #include <linux/param.h> | |
39 | #include <linux/string.h> | |
40 | #include <linux/mm.h> | |
41 | #include <linux/interrupt.h> | |
42 | #include <linux/timex.h> | |
43 | #include <linux/kernel_stat.h> | |
1da177e4 | 44 | #include <linux/time.h> |
0d948730 | 45 | #include <linux/clockchips.h> |
1da177e4 LT |
46 | #include <linux/init.h> |
47 | #include <linux/profile.h> | |
48 | #include <linux/cpu.h> | |
49 | #include <linux/security.h> | |
f2783c15 PM |
50 | #include <linux/percpu.h> |
51 | #include <linux/rtc.h> | |
092b8f34 | 52 | #include <linux/jiffies.h> |
c6622f63 | 53 | #include <linux/posix-timers.h> |
7d12e780 | 54 | #include <linux/irq.h> |
177996e6 | 55 | #include <linux/delay.h> |
e360adbe | 56 | #include <linux/irq_work.h> |
6795b85c | 57 | #include <asm/trace.h> |
1da177e4 | 58 | |
1da177e4 LT |
59 | #include <asm/io.h> |
60 | #include <asm/processor.h> | |
61 | #include <asm/nvram.h> | |
62 | #include <asm/cache.h> | |
63 | #include <asm/machdep.h> | |
1da177e4 LT |
64 | #include <asm/uaccess.h> |
65 | #include <asm/time.h> | |
1da177e4 | 66 | #include <asm/prom.h> |
f2783c15 PM |
67 | #include <asm/irq.h> |
68 | #include <asm/div64.h> | |
2249ca9d | 69 | #include <asm/smp.h> |
a7f290da | 70 | #include <asm/vdso_datapage.h> |
1ababe11 | 71 | #include <asm/firmware.h> |
06b8e878 | 72 | #include <asm/cputime.h> |
1da177e4 | 73 | |
4a4cfe38 TB |
74 | /* powerpc clocksource/clockevent code */ |
75 | ||
d831d0b8 | 76 | #include <linux/clockchips.h> |
189374ae | 77 | #include <linux/timekeeper_internal.h> |
4a4cfe38 | 78 | |
8e19608e | 79 | static cycle_t rtc_read(struct clocksource *); |
4a4cfe38 TB |
80 | static struct clocksource clocksource_rtc = { |
81 | .name = "rtc", | |
82 | .rating = 400, | |
83 | .flags = CLOCK_SOURCE_IS_CONTINUOUS, | |
84 | .mask = CLOCKSOURCE_MASK(64), | |
4a4cfe38 TB |
85 | .read = rtc_read, |
86 | }; | |
87 | ||
8e19608e | 88 | static cycle_t timebase_read(struct clocksource *); |
4a4cfe38 TB |
89 | static struct clocksource clocksource_timebase = { |
90 | .name = "timebase", | |
91 | .rating = 400, | |
92 | .flags = CLOCK_SOURCE_IS_CONTINUOUS, | |
93 | .mask = CLOCKSOURCE_MASK(64), | |
4a4cfe38 TB |
94 | .read = timebase_read, |
95 | }; | |
96 | ||
d831d0b8 TB |
97 | #define DECREMENTER_MAX 0x7fffffff |
98 | ||
99 | static int decrementer_set_next_event(unsigned long evt, | |
100 | struct clock_event_device *dev); | |
101 | static void decrementer_set_mode(enum clock_event_mode mode, | |
102 | struct clock_event_device *dev); | |
103 | ||
6e35994d | 104 | struct clock_event_device decrementer_clockevent = { |
621692cb AB |
105 | .name = "decrementer", |
106 | .rating = 200, | |
107 | .irq = 0, | |
108 | .set_next_event = decrementer_set_next_event, | |
109 | .set_mode = decrementer_set_mode, | |
0d948730 | 110 | .features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_C3STOP, |
d831d0b8 | 111 | }; |
6e35994d | 112 | EXPORT_SYMBOL(decrementer_clockevent); |
d831d0b8 | 113 | |
7df10275 AB |
114 | DEFINE_PER_CPU(u64, decrementers_next_tb); |
115 | static DEFINE_PER_CPU(struct clock_event_device, decrementers); | |
d831d0b8 | 116 | |
1da177e4 LT |
117 | #define XSEC_PER_SEC (1024*1024) |
118 | ||
f2783c15 PM |
119 | #ifdef CONFIG_PPC64 |
120 | #define SCALE_XSEC(xsec, max) (((xsec) * max) / XSEC_PER_SEC) | |
121 | #else | |
122 | /* compute ((xsec << 12) * max) >> 32 */ | |
123 | #define SCALE_XSEC(xsec, max) mulhwu((xsec) << 12, max) | |
124 | #endif | |
125 | ||
1da177e4 LT |
126 | unsigned long tb_ticks_per_jiffy; |
127 | unsigned long tb_ticks_per_usec = 100; /* sane default */ | |
128 | EXPORT_SYMBOL(tb_ticks_per_usec); | |
129 | unsigned long tb_ticks_per_sec; | |
2cf82c02 | 130 | EXPORT_SYMBOL(tb_ticks_per_sec); /* for cputime_t conversions */ |
092b8f34 | 131 | |
1da177e4 | 132 | DEFINE_SPINLOCK(rtc_lock); |
6ae3db11 | 133 | EXPORT_SYMBOL_GPL(rtc_lock); |
1da177e4 | 134 | |
fc9069fe TB |
135 | static u64 tb_to_ns_scale __read_mostly; |
136 | static unsigned tb_to_ns_shift __read_mostly; | |
364a1246 | 137 | static u64 boot_tb __read_mostly; |
1da177e4 | 138 | |
1da177e4 | 139 | extern struct timezone sys_tz; |
f2783c15 | 140 | static long timezone_offset; |
1da177e4 | 141 | |
10f7e7c1 | 142 | unsigned long ppc_proc_freq; |
55ec2fca | 143 | EXPORT_SYMBOL_GPL(ppc_proc_freq); |
10f7e7c1 | 144 | unsigned long ppc_tb_freq; |
55ec2fca | 145 | EXPORT_SYMBOL_GPL(ppc_tb_freq); |
96c44507 | 146 | |
abf917cd | 147 | #ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE |
c6622f63 PM |
148 | /* |
149 | * Factors for converting from cputime_t (timebase ticks) to | |
9f5072d4 | 150 | * jiffies, microseconds, seconds, and clock_t (1/USER_HZ seconds). |
c6622f63 PM |
151 | * These are all stored as 0.64 fixed-point binary fractions. |
152 | */ | |
153 | u64 __cputime_jiffies_factor; | |
2cf82c02 | 154 | EXPORT_SYMBOL(__cputime_jiffies_factor); |
9f5072d4 AS |
155 | u64 __cputime_usec_factor; |
156 | EXPORT_SYMBOL(__cputime_usec_factor); | |
c6622f63 | 157 | u64 __cputime_sec_factor; |
2cf82c02 | 158 | EXPORT_SYMBOL(__cputime_sec_factor); |
c6622f63 | 159 | u64 __cputime_clockt_factor; |
2cf82c02 | 160 | EXPORT_SYMBOL(__cputime_clockt_factor); |
06b8e878 MN |
161 | DEFINE_PER_CPU(unsigned long, cputime_last_delta); |
162 | DEFINE_PER_CPU(unsigned long, cputime_scaled_last_delta); | |
c6622f63 | 163 | |
a42548a1 SG |
164 | cputime_t cputime_one_jiffy; |
165 | ||
872e439a PM |
166 | void (*dtl_consumer)(struct dtl_entry *, u64); |
167 | ||
c6622f63 PM |
168 | static void calc_cputime_factors(void) |
169 | { | |
170 | struct div_result res; | |
171 | ||
172 | div128_by_32(HZ, 0, tb_ticks_per_sec, &res); | |
173 | __cputime_jiffies_factor = res.result_low; | |
9f5072d4 AS |
174 | div128_by_32(1000000, 0, tb_ticks_per_sec, &res); |
175 | __cputime_usec_factor = res.result_low; | |
c6622f63 PM |
176 | div128_by_32(1, 0, tb_ticks_per_sec, &res); |
177 | __cputime_sec_factor = res.result_low; | |
178 | div128_by_32(USER_HZ, 0, tb_ticks_per_sec, &res); | |
179 | __cputime_clockt_factor = res.result_low; | |
180 | } | |
181 | ||
182 | /* | |
cf9efce0 PM |
183 | * Read the SPURR on systems that have it, otherwise the PURR, |
184 | * or if that doesn't exist return the timebase value passed in. | |
c6622f63 | 185 | */ |
cf9efce0 | 186 | static u64 read_spurr(u64 tb) |
c6622f63 | 187 | { |
cf9efce0 PM |
188 | if (cpu_has_feature(CPU_FTR_SPURR)) |
189 | return mfspr(SPRN_SPURR); | |
c6622f63 PM |
190 | if (cpu_has_feature(CPU_FTR_PURR)) |
191 | return mfspr(SPRN_PURR); | |
cf9efce0 | 192 | return tb; |
c6622f63 PM |
193 | } |
194 | ||
cf9efce0 PM |
195 | #ifdef CONFIG_PPC_SPLPAR |
196 | ||
4603ac18 | 197 | /* |
cf9efce0 PM |
198 | * Scan the dispatch trace log and count up the stolen time. |
199 | * Should be called with interrupts disabled. | |
4603ac18 | 200 | */ |
cf9efce0 | 201 | static u64 scan_dispatch_log(u64 stop_tb) |
4603ac18 | 202 | { |
872e439a | 203 | u64 i = local_paca->dtl_ridx; |
cf9efce0 PM |
204 | struct dtl_entry *dtl = local_paca->dtl_curr; |
205 | struct dtl_entry *dtl_end = local_paca->dispatch_log_end; | |
206 | struct lppaca *vpa = local_paca->lppaca_ptr; | |
207 | u64 tb_delta; | |
208 | u64 stolen = 0; | |
209 | u64 dtb; | |
210 | ||
84ffae55 AB |
211 | if (!dtl) |
212 | return 0; | |
213 | ||
7ffcf8ec | 214 | if (i == be64_to_cpu(vpa->dtl_idx)) |
cf9efce0 | 215 | return 0; |
7ffcf8ec | 216 | while (i < be64_to_cpu(vpa->dtl_idx)) { |
7ffcf8ec AB |
217 | dtb = be64_to_cpu(dtl->timebase); |
218 | tb_delta = be32_to_cpu(dtl->enqueue_to_dispatch_time) + | |
219 | be32_to_cpu(dtl->ready_to_enqueue_time); | |
cf9efce0 | 220 | barrier(); |
7ffcf8ec | 221 | if (i + N_DISPATCH_LOG < be64_to_cpu(vpa->dtl_idx)) { |
cf9efce0 | 222 | /* buffer has overflowed */ |
7ffcf8ec | 223 | i = be64_to_cpu(vpa->dtl_idx) - N_DISPATCH_LOG; |
cf9efce0 PM |
224 | dtl = local_paca->dispatch_log + (i % N_DISPATCH_LOG); |
225 | continue; | |
226 | } | |
227 | if (dtb > stop_tb) | |
228 | break; | |
84b07386 AB |
229 | if (dtl_consumer) |
230 | dtl_consumer(dtl, i); | |
cf9efce0 PM |
231 | stolen += tb_delta; |
232 | ++i; | |
233 | ++dtl; | |
234 | if (dtl == dtl_end) | |
235 | dtl = local_paca->dispatch_log; | |
236 | } | |
237 | local_paca->dtl_ridx = i; | |
238 | local_paca->dtl_curr = dtl; | |
239 | return stolen; | |
4603ac18 MN |
240 | } |
241 | ||
cf9efce0 PM |
242 | /* |
243 | * Accumulate stolen time by scanning the dispatch trace log. | |
244 | * Called on entry from user mode. | |
245 | */ | |
246 | void accumulate_stolen_time(void) | |
247 | { | |
248 | u64 sst, ust; | |
249 | ||
b18ae08d | 250 | u8 save_soft_enabled = local_paca->soft_enabled; |
b18ae08d TH |
251 | |
252 | /* We are called early in the exception entry, before | |
253 | * soft/hard_enabled are sync'ed to the expected state | |
254 | * for the exception. We are hard disabled but the PACA | |
255 | * needs to reflect that so various debug stuff doesn't | |
256 | * complain | |
257 | */ | |
258 | local_paca->soft_enabled = 0; | |
b18ae08d TH |
259 | |
260 | sst = scan_dispatch_log(local_paca->starttime_user); | |
261 | ust = scan_dispatch_log(local_paca->starttime); | |
262 | local_paca->system_time -= sst; | |
263 | local_paca->user_time -= ust; | |
264 | local_paca->stolen_time += ust + sst; | |
265 | ||
266 | local_paca->soft_enabled = save_soft_enabled; | |
cf9efce0 PM |
267 | } |
268 | ||
269 | static inline u64 calculate_stolen_time(u64 stop_tb) | |
270 | { | |
271 | u64 stolen = 0; | |
272 | ||
7ffcf8ec | 273 | if (get_paca()->dtl_ridx != be64_to_cpu(get_lppaca()->dtl_idx)) { |
cf9efce0 PM |
274 | stolen = scan_dispatch_log(stop_tb); |
275 | get_paca()->system_time -= stolen; | |
276 | } | |
277 | ||
278 | stolen += get_paca()->stolen_time; | |
279 | get_paca()->stolen_time = 0; | |
280 | return stolen; | |
4603ac18 MN |
281 | } |
282 | ||
cf9efce0 PM |
283 | #else /* CONFIG_PPC_SPLPAR */ |
284 | static inline u64 calculate_stolen_time(u64 stop_tb) | |
285 | { | |
286 | return 0; | |
287 | } | |
288 | ||
289 | #endif /* CONFIG_PPC_SPLPAR */ | |
290 | ||
c6622f63 PM |
291 | /* |
292 | * Account time for a transition between system, hard irq | |
293 | * or soft irq state. | |
294 | */ | |
a7e1a9e3 FW |
295 | static u64 vtime_delta(struct task_struct *tsk, |
296 | u64 *sys_scaled, u64 *stolen) | |
c6622f63 | 297 | { |
a7e1a9e3 FW |
298 | u64 now, nowscaled, deltascaled; |
299 | u64 udelta, delta, user_scaled; | |
c6622f63 | 300 | |
1b2852b1 FW |
301 | WARN_ON_ONCE(!irqs_disabled()); |
302 | ||
cf9efce0 | 303 | now = mftb(); |
4603ac18 | 304 | nowscaled = read_spurr(now); |
cf9efce0 PM |
305 | get_paca()->system_time += now - get_paca()->starttime; |
306 | get_paca()->starttime = now; | |
4603ac18 MN |
307 | deltascaled = nowscaled - get_paca()->startspurr; |
308 | get_paca()->startspurr = nowscaled; | |
cf9efce0 | 309 | |
a7e1a9e3 | 310 | *stolen = calculate_stolen_time(now); |
cf9efce0 PM |
311 | |
312 | delta = get_paca()->system_time; | |
313 | get_paca()->system_time = 0; | |
314 | udelta = get_paca()->user_time - get_paca()->utime_sspurr; | |
315 | get_paca()->utime_sspurr = get_paca()->user_time; | |
316 | ||
317 | /* | |
318 | * Because we don't read the SPURR on every kernel entry/exit, | |
319 | * deltascaled includes both user and system SPURR ticks. | |
320 | * Apportion these ticks to system SPURR ticks and user | |
321 | * SPURR ticks in the same ratio as the system time (delta) | |
322 | * and user time (udelta) values obtained from the timebase | |
323 | * over the same interval. The system ticks get accounted here; | |
324 | * the user ticks get saved up in paca->user_time_scaled to be | |
325 | * used by account_process_tick. | |
326 | */ | |
a7e1a9e3 | 327 | *sys_scaled = delta; |
cf9efce0 PM |
328 | user_scaled = udelta; |
329 | if (deltascaled != delta + udelta) { | |
330 | if (udelta) { | |
a7e1a9e3 FW |
331 | *sys_scaled = deltascaled * delta / (delta + udelta); |
332 | user_scaled = deltascaled - *sys_scaled; | |
cf9efce0 | 333 | } else { |
a7e1a9e3 | 334 | *sys_scaled = deltascaled; |
cf9efce0 PM |
335 | } |
336 | } | |
337 | get_paca()->user_time_scaled += user_scaled; | |
338 | ||
a7e1a9e3 FW |
339 | return delta; |
340 | } | |
341 | ||
fd25b4c2 | 342 | void vtime_account_system(struct task_struct *tsk) |
a7e1a9e3 FW |
343 | { |
344 | u64 delta, sys_scaled, stolen; | |
345 | ||
346 | delta = vtime_delta(tsk, &sys_scaled, &stolen); | |
347 | account_system_time(tsk, 0, delta, sys_scaled); | |
348 | if (stolen) | |
349 | account_steal_time(stolen); | |
350 | } | |
c11f11fc | 351 | EXPORT_SYMBOL_GPL(vtime_account_system); |
a7e1a9e3 | 352 | |
fd25b4c2 | 353 | void vtime_account_idle(struct task_struct *tsk) |
a7e1a9e3 FW |
354 | { |
355 | u64 delta, sys_scaled, stolen; | |
356 | ||
357 | delta = vtime_delta(tsk, &sys_scaled, &stolen); | |
358 | account_idle_time(delta + stolen); | |
c6622f63 PM |
359 | } |
360 | ||
361 | /* | |
bcebdf84 FW |
362 | * Transfer the user time accumulated in the paca |
363 | * by the exception entry and exit code to the generic | |
364 | * process user time records. | |
c6622f63 | 365 | * Must be called with interrupts disabled. |
bcebdf84 FW |
366 | * Assumes that vtime_account_system/idle() has been called |
367 | * recently (i.e. since the last entry from usermode) so that | |
cf9efce0 | 368 | * get_paca()->user_time_scaled is up to date. |
c6622f63 | 369 | */ |
bcebdf84 | 370 | void vtime_account_user(struct task_struct *tsk) |
c6622f63 | 371 | { |
4603ac18 | 372 | cputime_t utime, utimescaled; |
c6622f63 PM |
373 | |
374 | utime = get_paca()->user_time; | |
cf9efce0 | 375 | utimescaled = get_paca()->user_time_scaled; |
c6622f63 | 376 | get_paca()->user_time = 0; |
cf9efce0 PM |
377 | get_paca()->user_time_scaled = 0; |
378 | get_paca()->utime_sspurr = 0; | |
457533a7 | 379 | account_user_time(tsk, utime, utimescaled); |
c6622f63 PM |
380 | } |
381 | ||
abf917cd | 382 | #else /* ! CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */ |
c6622f63 | 383 | #define calc_cputime_factors() |
c6622f63 PM |
384 | #endif |
385 | ||
6defa38b PM |
386 | void __delay(unsigned long loops) |
387 | { | |
388 | unsigned long start; | |
389 | int diff; | |
390 | ||
391 | if (__USE_RTC()) { | |
392 | start = get_rtcl(); | |
393 | do { | |
394 | /* the RTCL register wraps at 1000000000 */ | |
395 | diff = get_rtcl() - start; | |
396 | if (diff < 0) | |
397 | diff += 1000000000; | |
398 | } while (diff < loops); | |
399 | } else { | |
400 | start = get_tbl(); | |
401 | while (get_tbl() - start < loops) | |
402 | HMT_low(); | |
403 | HMT_medium(); | |
404 | } | |
405 | } | |
406 | EXPORT_SYMBOL(__delay); | |
407 | ||
408 | void udelay(unsigned long usecs) | |
409 | { | |
410 | __delay(tb_ticks_per_usec * usecs); | |
411 | } | |
412 | EXPORT_SYMBOL(udelay); | |
413 | ||
1da177e4 LT |
414 | #ifdef CONFIG_SMP |
415 | unsigned long profile_pc(struct pt_regs *regs) | |
416 | { | |
417 | unsigned long pc = instruction_pointer(regs); | |
418 | ||
419 | if (in_lock_functions(pc)) | |
420 | return regs->link; | |
421 | ||
422 | return pc; | |
423 | } | |
424 | EXPORT_SYMBOL(profile_pc); | |
425 | #endif | |
426 | ||
e360adbe | 427 | #ifdef CONFIG_IRQ_WORK |
105988c0 | 428 | |
0fe1ac48 PM |
429 | /* |
430 | * 64-bit uses a byte in the PACA, 32-bit uses a per-cpu variable... | |
431 | */ | |
432 | #ifdef CONFIG_PPC64 | |
e360adbe | 433 | static inline unsigned long test_irq_work_pending(void) |
105988c0 | 434 | { |
0fe1ac48 PM |
435 | unsigned long x; |
436 | ||
437 | asm volatile("lbz %0,%1(13)" | |
438 | : "=r" (x) | |
e360adbe | 439 | : "i" (offsetof(struct paca_struct, irq_work_pending))); |
0fe1ac48 PM |
440 | return x; |
441 | } | |
442 | ||
e360adbe | 443 | static inline void set_irq_work_pending_flag(void) |
0fe1ac48 PM |
444 | { |
445 | asm volatile("stb %0,%1(13)" : : | |
446 | "r" (1), | |
e360adbe | 447 | "i" (offsetof(struct paca_struct, irq_work_pending))); |
0fe1ac48 PM |
448 | } |
449 | ||
e360adbe | 450 | static inline void clear_irq_work_pending(void) |
0fe1ac48 PM |
451 | { |
452 | asm volatile("stb %0,%1(13)" : : | |
453 | "r" (0), | |
e360adbe | 454 | "i" (offsetof(struct paca_struct, irq_work_pending))); |
105988c0 PM |
455 | } |
456 | ||
0fe1ac48 PM |
457 | #else /* 32-bit */ |
458 | ||
e360adbe | 459 | DEFINE_PER_CPU(u8, irq_work_pending); |
0fe1ac48 | 460 | |
69111bac CL |
461 | #define set_irq_work_pending_flag() __this_cpu_write(irq_work_pending, 1) |
462 | #define test_irq_work_pending() __this_cpu_read(irq_work_pending) | |
463 | #define clear_irq_work_pending() __this_cpu_write(irq_work_pending, 0) | |
105988c0 | 464 | |
0fe1ac48 PM |
465 | #endif /* 32 vs 64 bit */ |
466 | ||
4f8b50bb | 467 | void arch_irq_work_raise(void) |
0fe1ac48 PM |
468 | { |
469 | preempt_disable(); | |
e360adbe | 470 | set_irq_work_pending_flag(); |
0fe1ac48 PM |
471 | set_dec(1); |
472 | preempt_enable(); | |
473 | } | |
474 | ||
e360adbe | 475 | #else /* CONFIG_IRQ_WORK */ |
105988c0 | 476 | |
e360adbe PZ |
477 | #define test_irq_work_pending() 0 |
478 | #define clear_irq_work_pending() | |
105988c0 | 479 | |
e360adbe | 480 | #endif /* CONFIG_IRQ_WORK */ |
105988c0 | 481 | |
e51df2c1 | 482 | static void __timer_interrupt(void) |
1b783955 PM |
483 | { |
484 | struct pt_regs *regs = get_irq_regs(); | |
69111bac CL |
485 | u64 *next_tb = this_cpu_ptr(&decrementers_next_tb); |
486 | struct clock_event_device *evt = this_cpu_ptr(&decrementers); | |
1b783955 PM |
487 | u64 now; |
488 | ||
489 | trace_timer_interrupt_entry(regs); | |
490 | ||
491 | if (test_irq_work_pending()) { | |
492 | clear_irq_work_pending(); | |
493 | irq_work_run(); | |
494 | } | |
495 | ||
496 | now = get_tb_or_rtc(); | |
497 | if (now >= *next_tb) { | |
498 | *next_tb = ~(u64)0; | |
499 | if (evt->event_handler) | |
500 | evt->event_handler(evt); | |
69111bac | 501 | __this_cpu_inc(irq_stat.timer_irqs_event); |
1b783955 PM |
502 | } else { |
503 | now = *next_tb - now; | |
504 | if (now <= DECREMENTER_MAX) | |
505 | set_dec((int)now); | |
506 | /* We may have raced with new irq work */ | |
507 | if (test_irq_work_pending()) | |
508 | set_dec(1); | |
69111bac | 509 | __this_cpu_inc(irq_stat.timer_irqs_others); |
1b783955 PM |
510 | } |
511 | ||
512 | #ifdef CONFIG_PPC64 | |
513 | /* collect purr register values often, for accurate calculations */ | |
514 | if (firmware_has_feature(FW_FEATURE_SPLPAR)) { | |
69111bac | 515 | struct cpu_usage *cu = this_cpu_ptr(&cpu_usage_array); |
1b783955 PM |
516 | cu->current_tb = mfspr(SPRN_PURR); |
517 | } | |
518 | #endif | |
519 | ||
520 | trace_timer_interrupt_exit(regs); | |
521 | } | |
522 | ||
1da177e4 LT |
523 | /* |
524 | * timer_interrupt - gets called when the decrementer overflows, | |
525 | * with interrupts disabled. | |
526 | */ | |
c7aeffc4 | 527 | void timer_interrupt(struct pt_regs * regs) |
1da177e4 | 528 | { |
7d12e780 | 529 | struct pt_regs *old_regs; |
69111bac | 530 | u64 *next_tb = this_cpu_ptr(&decrementers_next_tb); |
d831d0b8 | 531 | |
963e5d3b BH |
532 | /* Ensure a positive value is written to the decrementer, or else |
533 | * some CPUs will continue to take decrementer exceptions. | |
534 | */ | |
535 | set_dec(DECREMENTER_MAX); | |
536 | ||
537 | /* Some implementations of hotplug will get timer interrupts while | |
689dfa89 TC |
538 | * offline, just ignore these and we also need to set |
539 | * decrementers_next_tb as MAX to make sure __check_irq_replay | |
540 | * don't replay timer interrupt when return, otherwise we'll trap | |
541 | * here infinitely :( | |
963e5d3b | 542 | */ |
689dfa89 TC |
543 | if (!cpu_online(smp_processor_id())) { |
544 | *next_tb = ~(u64)0; | |
963e5d3b | 545 | return; |
689dfa89 | 546 | } |
963e5d3b | 547 | |
7230c564 BH |
548 | /* Conditionally hard-enable interrupts now that the DEC has been |
549 | * bumped to its maximum value | |
550 | */ | |
551 | may_hard_irq_enable(); | |
552 | ||
89713ed1 | 553 | |
6e0fdf9a | 554 | #if defined(CONFIG_PPC32) && defined(CONFIG_PPC_PMAC) |
f2783c15 PM |
555 | if (atomic_read(&ppc_n_lost_interrupts) != 0) |
556 | do_IRQ(regs); | |
557 | #endif | |
1da177e4 | 558 | |
7d12e780 | 559 | old_regs = set_irq_regs(regs); |
1da177e4 LT |
560 | irq_enter(); |
561 | ||
1b783955 | 562 | __timer_interrupt(); |
1da177e4 | 563 | irq_exit(); |
7d12e780 | 564 | set_irq_regs(old_regs); |
1da177e4 LT |
565 | } |
566 | ||
dabe859e PM |
567 | /* |
568 | * Hypervisor decrementer interrupts shouldn't occur but are sometimes | |
569 | * left pending on exit from a KVM guest. We don't need to do anything | |
570 | * to clear them, as they are edge-triggered. | |
571 | */ | |
572 | void hdec_interrupt(struct pt_regs *regs) | |
573 | { | |
574 | } | |
575 | ||
7ac5dde9 | 576 | #ifdef CONFIG_SUSPEND |
d75d68cf | 577 | static void generic_suspend_disable_irqs(void) |
7ac5dde9 | 578 | { |
7ac5dde9 SW |
579 | /* Disable the decrementer, so that it doesn't interfere |
580 | * with suspending. | |
581 | */ | |
582 | ||
621692cb | 583 | set_dec(DECREMENTER_MAX); |
7ac5dde9 | 584 | local_irq_disable(); |
621692cb | 585 | set_dec(DECREMENTER_MAX); |
7ac5dde9 SW |
586 | } |
587 | ||
d75d68cf | 588 | static void generic_suspend_enable_irqs(void) |
7ac5dde9 | 589 | { |
7ac5dde9 | 590 | local_irq_enable(); |
7ac5dde9 SW |
591 | } |
592 | ||
593 | /* Overrides the weak version in kernel/power/main.c */ | |
594 | void arch_suspend_disable_irqs(void) | |
595 | { | |
596 | if (ppc_md.suspend_disable_irqs) | |
597 | ppc_md.suspend_disable_irqs(); | |
598 | generic_suspend_disable_irqs(); | |
599 | } | |
600 | ||
601 | /* Overrides the weak version in kernel/power/main.c */ | |
602 | void arch_suspend_enable_irqs(void) | |
603 | { | |
604 | generic_suspend_enable_irqs(); | |
605 | if (ppc_md.suspend_enable_irqs) | |
606 | ppc_md.suspend_enable_irqs(); | |
607 | } | |
608 | #endif | |
609 | ||
1da177e4 LT |
610 | /* |
611 | * Scheduler clock - returns current time in nanosec units. | |
612 | * | |
613 | * Note: mulhdu(a, b) (multiply high double unsigned) returns | |
614 | * the high 64 bits of a * b, i.e. (a * b) >> 64, where a and b | |
615 | * are 64-bit unsigned numbers. | |
616 | */ | |
617 | unsigned long long sched_clock(void) | |
618 | { | |
96c44507 PM |
619 | if (__USE_RTC()) |
620 | return get_rtc(); | |
fc9069fe | 621 | return mulhdu(get_tb() - boot_tb, tb_to_ns_scale) << tb_to_ns_shift; |
1da177e4 LT |
622 | } |
623 | ||
0bb474a4 | 624 | static int __init get_freq(char *name, int cells, unsigned long *val) |
10f7e7c1 AB |
625 | { |
626 | struct device_node *cpu; | |
6f7aba7b | 627 | const __be32 *fp; |
0bb474a4 | 628 | int found = 0; |
10f7e7c1 | 629 | |
0bb474a4 | 630 | /* The cpu node should have timebase and clock frequency properties */ |
10f7e7c1 AB |
631 | cpu = of_find_node_by_type(NULL, "cpu"); |
632 | ||
d8a8188d | 633 | if (cpu) { |
e2eb6392 | 634 | fp = of_get_property(cpu, name, NULL); |
d8a8188d | 635 | if (fp) { |
0bb474a4 | 636 | found = 1; |
a4dc7ff0 | 637 | *val = of_read_ulong(fp, cells); |
10f7e7c1 | 638 | } |
0bb474a4 AB |
639 | |
640 | of_node_put(cpu); | |
10f7e7c1 | 641 | } |
0bb474a4 AB |
642 | |
643 | return found; | |
644 | } | |
645 | ||
e51df2c1 | 646 | static void start_cpu_decrementer(void) |
77c0a700 BH |
647 | { |
648 | #if defined(CONFIG_BOOKE) || defined(CONFIG_40x) | |
649 | /* Clear any pending timer interrupts */ | |
650 | mtspr(SPRN_TSR, TSR_ENW | TSR_WIS | TSR_DIS | TSR_FIS); | |
651 | ||
652 | /* Enable decrementer interrupt */ | |
653 | mtspr(SPRN_TCR, TCR_DIE); | |
654 | #endif /* defined(CONFIG_BOOKE) || defined(CONFIG_40x) */ | |
655 | } | |
656 | ||
0bb474a4 AB |
657 | void __init generic_calibrate_decr(void) |
658 | { | |
659 | ppc_tb_freq = DEFAULT_TB_FREQ; /* hardcoded default */ | |
660 | ||
661 | if (!get_freq("ibm,extended-timebase-frequency", 2, &ppc_tb_freq) && | |
662 | !get_freq("timebase-frequency", 1, &ppc_tb_freq)) { | |
663 | ||
10f7e7c1 AB |
664 | printk(KERN_ERR "WARNING: Estimating decrementer frequency " |
665 | "(not found)\n"); | |
0bb474a4 | 666 | } |
10f7e7c1 | 667 | |
0bb474a4 AB |
668 | ppc_proc_freq = DEFAULT_PROC_FREQ; /* hardcoded default */ |
669 | ||
670 | if (!get_freq("ibm,extended-clock-frequency", 2, &ppc_proc_freq) && | |
671 | !get_freq("clock-frequency", 1, &ppc_proc_freq)) { | |
672 | ||
673 | printk(KERN_ERR "WARNING: Estimating processor frequency " | |
674 | "(not found)\n"); | |
10f7e7c1 | 675 | } |
10f7e7c1 | 676 | } |
10f7e7c1 | 677 | |
aa3be5f3 | 678 | int update_persistent_clock(struct timespec now) |
f2783c15 PM |
679 | { |
680 | struct rtc_time tm; | |
681 | ||
aa3be5f3 | 682 | if (!ppc_md.set_rtc_time) |
023f333a | 683 | return -ENODEV; |
aa3be5f3 TB |
684 | |
685 | to_tm(now.tv_sec + 1 + timezone_offset, &tm); | |
686 | tm.tm_year -= 1900; | |
687 | tm.tm_mon -= 1; | |
688 | ||
689 | return ppc_md.set_rtc_time(&tm); | |
690 | } | |
691 | ||
978d7eb3 | 692 | static void __read_persistent_clock(struct timespec *ts) |
aa3be5f3 TB |
693 | { |
694 | struct rtc_time tm; | |
695 | static int first = 1; | |
696 | ||
d90246cd | 697 | ts->tv_nsec = 0; |
aa3be5f3 TB |
698 | /* XXX this is a litle fragile but will work okay in the short term */ |
699 | if (first) { | |
700 | first = 0; | |
701 | if (ppc_md.time_init) | |
702 | timezone_offset = ppc_md.time_init(); | |
703 | ||
704 | /* get_boot_time() isn't guaranteed to be safe to call late */ | |
d90246cd MS |
705 | if (ppc_md.get_boot_time) { |
706 | ts->tv_sec = ppc_md.get_boot_time() - timezone_offset; | |
707 | return; | |
708 | } | |
709 | } | |
710 | if (!ppc_md.get_rtc_time) { | |
711 | ts->tv_sec = 0; | |
712 | return; | |
aa3be5f3 | 713 | } |
f2783c15 | 714 | ppc_md.get_rtc_time(&tm); |
978d7eb3 | 715 | |
d4f587c6 MS |
716 | ts->tv_sec = mktime(tm.tm_year+1900, tm.tm_mon+1, tm.tm_mday, |
717 | tm.tm_hour, tm.tm_min, tm.tm_sec); | |
f2783c15 PM |
718 | } |
719 | ||
978d7eb3 BH |
720 | void read_persistent_clock(struct timespec *ts) |
721 | { | |
722 | __read_persistent_clock(ts); | |
723 | ||
724 | /* Sanitize it in case real time clock is set below EPOCH */ | |
725 | if (ts->tv_sec < 0) { | |
726 | ts->tv_sec = 0; | |
727 | ts->tv_nsec = 0; | |
728 | } | |
729 | ||
730 | } | |
731 | ||
4a4cfe38 | 732 | /* clocksource code */ |
8e19608e | 733 | static cycle_t rtc_read(struct clocksource *cs) |
4a4cfe38 TB |
734 | { |
735 | return (cycle_t)get_rtc(); | |
736 | } | |
737 | ||
8e19608e | 738 | static cycle_t timebase_read(struct clocksource *cs) |
4a4cfe38 TB |
739 | { |
740 | return (cycle_t)get_tb(); | |
741 | } | |
742 | ||
70639421 | 743 | void update_vsyscall_old(struct timespec *wall_time, struct timespec *wtm, |
4a0e6377 | 744 | struct clocksource *clock, u32 mult, cycle_t cycle_last) |
4a4cfe38 | 745 | { |
b0797b60 | 746 | u64 new_tb_to_xs, new_stamp_xsec; |
47916be4 | 747 | u32 frac_sec; |
4a4cfe38 TB |
748 | |
749 | if (clock != &clocksource_timebase) | |
750 | return; | |
751 | ||
752 | /* Make userspace gettimeofday spin until we're done. */ | |
753 | ++vdso_data->tb_update_count; | |
754 | smp_mb(); | |
755 | ||
11b8633a AB |
756 | /* 19342813113834067 ~= 2^(20+64) / 1e9 */ |
757 | new_tb_to_xs = (u64) mult * (19342813113834067ULL >> clock->shift); | |
06d518e3 | 758 | new_stamp_xsec = (u64) wall_time->tv_nsec * XSEC_PER_SEC; |
b0797b60 | 759 | do_div(new_stamp_xsec, 1000000000); |
06d518e3 | 760 | new_stamp_xsec += (u64) wall_time->tv_sec * XSEC_PER_SEC; |
b0797b60 | 761 | |
47916be4 TG |
762 | BUG_ON(wall_time->tv_nsec >= NSEC_PER_SEC); |
763 | /* this is tv_nsec / 1e9 as a 0.32 fraction */ | |
764 | frac_sec = ((u64) wall_time->tv_nsec * 18446744073ULL) >> 32; | |
765 | ||
b0797b60 JS |
766 | /* |
767 | * tb_update_count is used to allow the userspace gettimeofday code | |
768 | * to assure itself that it sees a consistent view of the tb_to_xs and | |
769 | * stamp_xsec variables. It reads the tb_update_count, then reads | |
770 | * tb_to_xs and stamp_xsec and then reads tb_update_count again. If | |
771 | * the two values of tb_update_count match and are even then the | |
772 | * tb_to_xs and stamp_xsec values are consistent. If not, then it | |
773 | * loops back and reads them again until this criteria is met. | |
774 | * We expect the caller to have done the first increment of | |
775 | * vdso_data->tb_update_count already. | |
776 | */ | |
4a0e6377 | 777 | vdso_data->tb_orig_stamp = cycle_last; |
b0797b60 JS |
778 | vdso_data->stamp_xsec = new_stamp_xsec; |
779 | vdso_data->tb_to_xs = new_tb_to_xs; | |
7615856e JS |
780 | vdso_data->wtom_clock_sec = wtm->tv_sec; |
781 | vdso_data->wtom_clock_nsec = wtm->tv_nsec; | |
06d518e3 | 782 | vdso_data->stamp_xtime = *wall_time; |
0e469db8 | 783 | vdso_data->stamp_sec_fraction = frac_sec; |
b0797b60 JS |
784 | smp_wmb(); |
785 | ++(vdso_data->tb_update_count); | |
4a4cfe38 TB |
786 | } |
787 | ||
788 | void update_vsyscall_tz(void) | |
789 | { | |
4a4cfe38 TB |
790 | vdso_data->tz_minuteswest = sys_tz.tz_minuteswest; |
791 | vdso_data->tz_dsttime = sys_tz.tz_dsttime; | |
4a4cfe38 TB |
792 | } |
793 | ||
1c21a293 | 794 | static void __init clocksource_init(void) |
4a4cfe38 TB |
795 | { |
796 | struct clocksource *clock; | |
797 | ||
798 | if (__USE_RTC()) | |
799 | clock = &clocksource_rtc; | |
800 | else | |
801 | clock = &clocksource_timebase; | |
802 | ||
11b8633a | 803 | if (clocksource_register_hz(clock, tb_ticks_per_sec)) { |
4a4cfe38 TB |
804 | printk(KERN_ERR "clocksource: %s is already registered\n", |
805 | clock->name); | |
806 | return; | |
807 | } | |
808 | ||
809 | printk(KERN_INFO "clocksource: %s mult[%x] shift[%d] registered\n", | |
810 | clock->name, clock->mult, clock->shift); | |
811 | } | |
812 | ||
d831d0b8 TB |
813 | static int decrementer_set_next_event(unsigned long evt, |
814 | struct clock_event_device *dev) | |
815 | { | |
69111bac | 816 | __this_cpu_write(decrementers_next_tb, get_tb_or_rtc() + evt); |
d831d0b8 | 817 | set_dec(evt); |
0215f7d8 BH |
818 | |
819 | /* We may have raced with new irq work */ | |
820 | if (test_irq_work_pending()) | |
821 | set_dec(1); | |
822 | ||
d831d0b8 TB |
823 | return 0; |
824 | } | |
825 | ||
826 | static void decrementer_set_mode(enum clock_event_mode mode, | |
827 | struct clock_event_device *dev) | |
828 | { | |
829 | if (mode != CLOCK_EVT_MODE_ONESHOT) | |
830 | decrementer_set_next_event(DECREMENTER_MAX, dev); | |
831 | } | |
832 | ||
1b67bee1 SB |
833 | /* Interrupt handler for the timer broadcast IPI */ |
834 | void tick_broadcast_ipi_handler(void) | |
835 | { | |
69111bac | 836 | u64 *next_tb = this_cpu_ptr(&decrementers_next_tb); |
1b783955 PM |
837 | |
838 | *next_tb = get_tb_or_rtc(); | |
839 | __timer_interrupt(); | |
1b67bee1 SB |
840 | } |
841 | ||
d831d0b8 TB |
842 | static void register_decrementer_clockevent(int cpu) |
843 | { | |
7df10275 | 844 | struct clock_event_device *dec = &per_cpu(decrementers, cpu); |
d831d0b8 TB |
845 | |
846 | *dec = decrementer_clockevent; | |
320ab2b0 | 847 | dec->cpumask = cpumask_of(cpu); |
d831d0b8 | 848 | |
b919ee82 AB |
849 | printk_once(KERN_DEBUG "clockevent: %s mult[%x] shift[%d] cpu[%d]\n", |
850 | dec->name, dec->mult, dec->shift, cpu); | |
d831d0b8 TB |
851 | |
852 | clockevents_register_device(dec); | |
853 | } | |
854 | ||
c481887f | 855 | static void __init init_decrementer_clockevent(void) |
d831d0b8 TB |
856 | { |
857 | int cpu = smp_processor_id(); | |
858 | ||
d8afc6fd AB |
859 | clockevents_calc_mult_shift(&decrementer_clockevent, ppc_tb_freq, 4); |
860 | ||
d831d0b8 TB |
861 | decrementer_clockevent.max_delta_ns = |
862 | clockevent_delta2ns(DECREMENTER_MAX, &decrementer_clockevent); | |
43875cc0 PM |
863 | decrementer_clockevent.min_delta_ns = |
864 | clockevent_delta2ns(2, &decrementer_clockevent); | |
d831d0b8 TB |
865 | |
866 | register_decrementer_clockevent(cpu); | |
867 | } | |
868 | ||
869 | void secondary_cpu_time_init(void) | |
870 | { | |
77c0a700 BH |
871 | /* Start the decrementer on CPUs that have manual control |
872 | * such as BookE | |
873 | */ | |
874 | start_cpu_decrementer(); | |
875 | ||
d831d0b8 TB |
876 | /* FIME: Should make unrelatred change to move snapshot_timebase |
877 | * call here ! */ | |
878 | register_decrementer_clockevent(smp_processor_id()); | |
879 | } | |
880 | ||
f2783c15 | 881 | /* This function is only called on the boot processor */ |
1da177e4 LT |
882 | void __init time_init(void) |
883 | { | |
1da177e4 | 884 | struct div_result res; |
d75d68cf | 885 | u64 scale; |
f2783c15 PM |
886 | unsigned shift; |
887 | ||
96c44507 PM |
888 | if (__USE_RTC()) { |
889 | /* 601 processor: dec counts down by 128 every 128ns */ | |
890 | ppc_tb_freq = 1000000000; | |
96c44507 PM |
891 | } else { |
892 | /* Normal PowerPC with timebase register */ | |
893 | ppc_md.calibrate_decr(); | |
224ad80a | 894 | printk(KERN_DEBUG "time_init: decrementer frequency = %lu.%.6lu MHz\n", |
96c44507 | 895 | ppc_tb_freq / 1000000, ppc_tb_freq % 1000000); |
224ad80a | 896 | printk(KERN_DEBUG "time_init: processor frequency = %lu.%.6lu MHz\n", |
96c44507 | 897 | ppc_proc_freq / 1000000, ppc_proc_freq % 1000000); |
96c44507 | 898 | } |
374e99d4 PM |
899 | |
900 | tb_ticks_per_jiffy = ppc_tb_freq / HZ; | |
092b8f34 | 901 | tb_ticks_per_sec = ppc_tb_freq; |
374e99d4 | 902 | tb_ticks_per_usec = ppc_tb_freq / 1000000; |
c6622f63 | 903 | calc_cputime_factors(); |
a42548a1 | 904 | setup_cputime_one_jiffy(); |
092b8f34 | 905 | |
1da177e4 LT |
906 | /* |
907 | * Compute scale factor for sched_clock. | |
908 | * The calibrate_decr() function has set tb_ticks_per_sec, | |
909 | * which is the timebase frequency. | |
910 | * We compute 1e9 * 2^64 / tb_ticks_per_sec and interpret | |
911 | * the 128-bit result as a 64.64 fixed-point number. | |
912 | * We then shift that number right until it is less than 1.0, | |
913 | * giving us the scale factor and shift count to use in | |
914 | * sched_clock(). | |
915 | */ | |
916 | div128_by_32(1000000000, 0, tb_ticks_per_sec, &res); | |
917 | scale = res.result_low; | |
918 | for (shift = 0; res.result_high != 0; ++shift) { | |
919 | scale = (scale >> 1) | (res.result_high << 63); | |
920 | res.result_high >>= 1; | |
921 | } | |
922 | tb_to_ns_scale = scale; | |
923 | tb_to_ns_shift = shift; | |
fc9069fe | 924 | /* Save the current timebase to pretty up CONFIG_PRINTK_TIME */ |
c27da339 | 925 | boot_tb = get_tb_or_rtc(); |
1da177e4 | 926 | |
092b8f34 | 927 | /* If platform provided a timezone (pmac), we correct the time */ |
621692cb | 928 | if (timezone_offset) { |
092b8f34 PM |
929 | sys_tz.tz_minuteswest = -timezone_offset / 60; |
930 | sys_tz.tz_dsttime = 0; | |
621692cb | 931 | } |
092b8f34 | 932 | |
a7f290da BH |
933 | vdso_data->tb_update_count = 0; |
934 | vdso_data->tb_ticks_per_sec = tb_ticks_per_sec; | |
1da177e4 | 935 | |
77c0a700 BH |
936 | /* Start the decrementer on CPUs that have manual control |
937 | * such as BookE | |
938 | */ | |
939 | start_cpu_decrementer(); | |
940 | ||
f5339277 SR |
941 | /* Register the clocksource */ |
942 | clocksource_init(); | |
4a4cfe38 | 943 | |
d831d0b8 | 944 | init_decrementer_clockevent(); |
0d948730 | 945 | tick_setup_hrtimer_broadcast(); |
1da177e4 LT |
946 | } |
947 | ||
1da177e4 | 948 | |
1da177e4 LT |
949 | #define FEBRUARY 2 |
950 | #define STARTOFTIME 1970 | |
951 | #define SECDAY 86400L | |
952 | #define SECYR (SECDAY * 365) | |
f2783c15 PM |
953 | #define leapyear(year) ((year) % 4 == 0 && \ |
954 | ((year) % 100 != 0 || (year) % 400 == 0)) | |
1da177e4 LT |
955 | #define days_in_year(a) (leapyear(a) ? 366 : 365) |
956 | #define days_in_month(a) (month_days[(a) - 1]) | |
957 | ||
958 | static int month_days[12] = { | |
959 | 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 | |
960 | }; | |
961 | ||
962 | /* | |
963 | * This only works for the Gregorian calendar - i.e. after 1752 (in the UK) | |
964 | */ | |
965 | void GregorianDay(struct rtc_time * tm) | |
966 | { | |
967 | int leapsToDate; | |
968 | int lastYear; | |
969 | int day; | |
970 | int MonthOffset[] = { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 }; | |
971 | ||
f2783c15 | 972 | lastYear = tm->tm_year - 1; |
1da177e4 LT |
973 | |
974 | /* | |
975 | * Number of leap corrections to apply up to end of last year | |
976 | */ | |
f2783c15 | 977 | leapsToDate = lastYear / 4 - lastYear / 100 + lastYear / 400; |
1da177e4 LT |
978 | |
979 | /* | |
980 | * This year is a leap year if it is divisible by 4 except when it is | |
981 | * divisible by 100 unless it is divisible by 400 | |
982 | * | |
f2783c15 | 983 | * e.g. 1904 was a leap year, 1900 was not, 1996 is, and 2000 was |
1da177e4 | 984 | */ |
f2783c15 | 985 | day = tm->tm_mon > 2 && leapyear(tm->tm_year); |
1da177e4 LT |
986 | |
987 | day += lastYear*365 + leapsToDate + MonthOffset[tm->tm_mon-1] + | |
988 | tm->tm_mday; | |
989 | ||
f2783c15 | 990 | tm->tm_wday = day % 7; |
1da177e4 | 991 | } |
16b1d26e | 992 | EXPORT_SYMBOL_GPL(GregorianDay); |
1da177e4 LT |
993 | |
994 | void to_tm(int tim, struct rtc_time * tm) | |
995 | { | |
996 | register int i; | |
997 | register long hms, day; | |
998 | ||
999 | day = tim / SECDAY; | |
1000 | hms = tim % SECDAY; | |
1001 | ||
1002 | /* Hours, minutes, seconds are easy */ | |
1003 | tm->tm_hour = hms / 3600; | |
1004 | tm->tm_min = (hms % 3600) / 60; | |
1005 | tm->tm_sec = (hms % 3600) % 60; | |
1006 | ||
1007 | /* Number of years in days */ | |
1008 | for (i = STARTOFTIME; day >= days_in_year(i); i++) | |
1009 | day -= days_in_year(i); | |
1010 | tm->tm_year = i; | |
1011 | ||
1012 | /* Number of months in days left */ | |
1013 | if (leapyear(tm->tm_year)) | |
1014 | days_in_month(FEBRUARY) = 29; | |
1015 | for (i = 1; day >= days_in_month(i); i++) | |
1016 | day -= days_in_month(i); | |
1017 | days_in_month(FEBRUARY) = 28; | |
1018 | tm->tm_mon = i; | |
1019 | ||
1020 | /* Days are what is left over (+1) from all that. */ | |
1021 | tm->tm_mday = day + 1; | |
1022 | ||
1023 | /* | |
1024 | * Determine the day of week | |
1025 | */ | |
1026 | GregorianDay(tm); | |
1027 | } | |
e1802b06 | 1028 | EXPORT_SYMBOL(to_tm); |
1da177e4 | 1029 | |
1da177e4 LT |
1030 | /* |
1031 | * Divide a 128-bit dividend by a 32-bit divisor, leaving a 128 bit | |
1032 | * result. | |
1033 | */ | |
f2783c15 PM |
1034 | void div128_by_32(u64 dividend_high, u64 dividend_low, |
1035 | unsigned divisor, struct div_result *dr) | |
1da177e4 | 1036 | { |
f2783c15 PM |
1037 | unsigned long a, b, c, d; |
1038 | unsigned long w, x, y, z; | |
1039 | u64 ra, rb, rc; | |
1da177e4 LT |
1040 | |
1041 | a = dividend_high >> 32; | |
1042 | b = dividend_high & 0xffffffff; | |
1043 | c = dividend_low >> 32; | |
1044 | d = dividend_low & 0xffffffff; | |
1045 | ||
f2783c15 PM |
1046 | w = a / divisor; |
1047 | ra = ((u64)(a - (w * divisor)) << 32) + b; | |
1048 | ||
f2783c15 PM |
1049 | rb = ((u64) do_div(ra, divisor) << 32) + c; |
1050 | x = ra; | |
1da177e4 | 1051 | |
f2783c15 PM |
1052 | rc = ((u64) do_div(rb, divisor) << 32) + d; |
1053 | y = rb; | |
1054 | ||
1055 | do_div(rc, divisor); | |
1056 | z = rc; | |
1da177e4 | 1057 | |
f2783c15 PM |
1058 | dr->result_high = ((u64)w << 32) + x; |
1059 | dr->result_low = ((u64)y << 32) + z; | |
1da177e4 LT |
1060 | |
1061 | } | |
bcd68a70 | 1062 | |
177996e6 BH |
1063 | /* We don't need to calibrate delay, we use the CPU timebase for that */ |
1064 | void calibrate_delay(void) | |
1065 | { | |
1066 | /* Some generic code (such as spinlock debug) use loops_per_jiffy | |
1067 | * as the number of __delay(1) in a jiffy, so make it so | |
1068 | */ | |
1069 | loops_per_jiffy = tb_ticks_per_jiffy; | |
1070 | } | |
1071 | ||
bcd68a70 GU |
1072 | static int __init rtc_init(void) |
1073 | { | |
1074 | struct platform_device *pdev; | |
1075 | ||
1076 | if (!ppc_md.get_rtc_time) | |
1077 | return -ENODEV; | |
1078 | ||
1079 | pdev = platform_device_register_simple("rtc-generic", -1, NULL, 0); | |
bcd68a70 | 1080 | |
8c6ffba0 | 1081 | return PTR_ERR_OR_ZERO(pdev); |
bcd68a70 GU |
1082 | } |
1083 | ||
1084 | module_init(rtc_init); |