Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2001 MontaVista Software Inc. |
| 3 | * Author: Jun Sun, jsun@mvista.com or jsun@junsun.net |
| 4 | * Copyright (c) 2003, 2004 Maciej W. Rozycki |
| 5 | * |
| 6 | * Common time service routines for MIPS machines. See |
| 7 | * Documentation/mips/time.README. |
| 8 | * |
| 9 | * This program is free software; you can redistribute it and/or modify it |
| 10 | * under the terms of the GNU General Public License as published by the |
| 11 | * Free Software Foundation; either version 2 of the License, or (at your |
| 12 | * option) any later version. |
| 13 | */ |
| 14 | #include <linux/types.h> |
| 15 | #include <linux/kernel.h> |
| 16 | #include <linux/init.h> |
| 17 | #include <linux/sched.h> |
| 18 | #include <linux/param.h> |
| 19 | #include <linux/time.h> |
| 20 | #include <linux/timex.h> |
| 21 | #include <linux/smp.h> |
| 22 | #include <linux/kernel_stat.h> |
| 23 | #include <linux/spinlock.h> |
| 24 | #include <linux/interrupt.h> |
| 25 | #include <linux/module.h> |
| 26 | |
| 27 | #include <asm/bootinfo.h> |
Ralf Baechle | ec74e36 | 2005-07-13 11:48:45 +0000 | [diff] [blame] | 28 | #include <asm/cache.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 29 | #include <asm/compiler.h> |
| 30 | #include <asm/cpu.h> |
| 31 | #include <asm/cpu-features.h> |
| 32 | #include <asm/div64.h> |
| 33 | #include <asm/sections.h> |
| 34 | #include <asm/time.h> |
| 35 | |
| 36 | /* |
| 37 | * The integer part of the number of usecs per jiffy is taken from tick, |
| 38 | * but the fractional part is not recorded, so we calculate it using the |
| 39 | * initial value of HZ. This aids systems where tick isn't really an |
| 40 | * integer (e.g. for HZ = 128). |
| 41 | */ |
| 42 | #define USECS_PER_JIFFY TICK_SIZE |
| 43 | #define USECS_PER_JIFFY_FRAC ((unsigned long)(u32)((1000000ULL << 32) / HZ)) |
| 44 | |
| 45 | #define TICK_SIZE (tick_nsec / 1000) |
| 46 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 47 | /* |
| 48 | * forward reference |
| 49 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 50 | DEFINE_SPINLOCK(rtc_lock); |
| 51 | |
| 52 | /* |
| 53 | * By default we provide the null RTC ops |
| 54 | */ |
| 55 | static unsigned long null_rtc_get_time(void) |
| 56 | { |
| 57 | return mktime(2000, 1, 1, 0, 0, 0); |
| 58 | } |
| 59 | |
| 60 | static int null_rtc_set_time(unsigned long sec) |
| 61 | { |
| 62 | return 0; |
| 63 | } |
| 64 | |
Yoichi Yuasa | d23ee8f | 2006-03-27 01:16:33 -0800 | [diff] [blame] | 65 | unsigned long (*rtc_mips_get_time)(void) = null_rtc_get_time; |
| 66 | int (*rtc_mips_set_time)(unsigned long) = null_rtc_set_time; |
| 67 | int (*rtc_mips_set_mmss)(unsigned long); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 68 | |
| 69 | |
| 70 | /* usecs per counter cycle, shifted to left by 32 bits */ |
| 71 | static unsigned int sll32_usecs_per_cycle; |
| 72 | |
| 73 | /* how many counter cycles in a jiffy */ |
Ralf Baechle | ec74e36 | 2005-07-13 11:48:45 +0000 | [diff] [blame] | 74 | static unsigned long cycles_per_jiffy __read_mostly; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 75 | |
| 76 | /* Cycle counter value at the previous timer interrupt.. */ |
| 77 | static unsigned int timerhi, timerlo; |
| 78 | |
| 79 | /* expirelo is the count value for next CPU timer interrupt */ |
| 80 | static unsigned int expirelo; |
| 81 | |
| 82 | |
| 83 | /* |
| 84 | * Null timer ack for systems not needing one (e.g. i8254). |
| 85 | */ |
| 86 | static void null_timer_ack(void) { /* nothing */ } |
| 87 | |
| 88 | /* |
| 89 | * Null high precision timer functions for systems lacking one. |
| 90 | */ |
| 91 | static unsigned int null_hpt_read(void) |
| 92 | { |
| 93 | return 0; |
| 94 | } |
| 95 | |
Ralf Baechle | ec74e36 | 2005-07-13 11:48:45 +0000 | [diff] [blame] | 96 | static void null_hpt_init(unsigned int count) |
| 97 | { |
| 98 | /* nothing */ |
| 99 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 100 | |
| 101 | |
| 102 | /* |
| 103 | * Timer ack for an R4k-compatible timer of a known frequency. |
| 104 | */ |
| 105 | static void c0_timer_ack(void) |
| 106 | { |
| 107 | unsigned int count; |
| 108 | |
Pete Popov | bdf21b1 | 2005-07-14 17:47:57 +0000 | [diff] [blame] | 109 | #ifndef CONFIG_SOC_PNX8550 /* pnx8550 resets to zero */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 110 | /* Ack this timer interrupt and set the next one. */ |
| 111 | expirelo += cycles_per_jiffy; |
Pete Popov | bdf21b1 | 2005-07-14 17:47:57 +0000 | [diff] [blame] | 112 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 113 | write_c0_compare(expirelo); |
| 114 | |
| 115 | /* Check to see if we have missed any timer interrupts. */ |
Ralf Baechle | 41c594a | 2006-04-05 09:45:45 +0100 | [diff] [blame] | 116 | while (((count = read_c0_count()) - expirelo) < 0x7fffffff) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 117 | /* missed_timer_count++; */ |
| 118 | expirelo = count + cycles_per_jiffy; |
| 119 | write_c0_compare(expirelo); |
| 120 | } |
| 121 | } |
| 122 | |
| 123 | /* |
| 124 | * High precision timer functions for a R4k-compatible timer. |
| 125 | */ |
| 126 | static unsigned int c0_hpt_read(void) |
| 127 | { |
| 128 | return read_c0_count(); |
| 129 | } |
| 130 | |
| 131 | /* For use solely as a high precision timer. */ |
| 132 | static void c0_hpt_init(unsigned int count) |
| 133 | { |
| 134 | write_c0_count(read_c0_count() - count); |
| 135 | } |
| 136 | |
| 137 | /* For use both as a high precision timer and an interrupt source. */ |
| 138 | static void c0_hpt_timer_init(unsigned int count) |
| 139 | { |
| 140 | count = read_c0_count() - count; |
| 141 | expirelo = (count / cycles_per_jiffy + 1) * cycles_per_jiffy; |
| 142 | write_c0_count(expirelo - cycles_per_jiffy); |
| 143 | write_c0_compare(expirelo); |
| 144 | write_c0_count(count); |
| 145 | } |
| 146 | |
| 147 | int (*mips_timer_state)(void); |
| 148 | void (*mips_timer_ack)(void); |
| 149 | unsigned int (*mips_hpt_read)(void); |
| 150 | void (*mips_hpt_init)(unsigned int); |
| 151 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 152 | /* |
| 153 | * Gettimeoffset routines. These routines returns the time duration |
| 154 | * since last timer interrupt in usecs. |
| 155 | * |
| 156 | * If the exact CPU counter frequency is known, use fixed_rate_gettimeoffset. |
| 157 | * Otherwise use calibrate_gettimeoffset() |
| 158 | * |
| 159 | * If the CPU does not have the counter register, you can either supply |
| 160 | * your own gettimeoffset() routine, or use null_gettimeoffset(), which |
| 161 | * gives the same resolution as HZ. |
| 162 | */ |
| 163 | |
| 164 | static unsigned long null_gettimeoffset(void) |
| 165 | { |
| 166 | return 0; |
| 167 | } |
| 168 | |
| 169 | |
| 170 | /* The function pointer to one of the gettimeoffset funcs. */ |
| 171 | unsigned long (*do_gettimeoffset)(void) = null_gettimeoffset; |
| 172 | |
| 173 | |
| 174 | static unsigned long fixed_rate_gettimeoffset(void) |
| 175 | { |
| 176 | u32 count; |
| 177 | unsigned long res; |
| 178 | |
| 179 | /* Get last timer tick in absolute kernel time */ |
| 180 | count = mips_hpt_read(); |
| 181 | |
| 182 | /* .. relative to previous jiffy (32 bits is enough) */ |
| 183 | count -= timerlo; |
| 184 | |
| 185 | __asm__("multu %1,%2" |
| 186 | : "=h" (res) |
| 187 | : "r" (count), "r" (sll32_usecs_per_cycle) |
| 188 | : "lo", GCC_REG_ACCUM); |
| 189 | |
| 190 | /* |
| 191 | * Due to possible jiffies inconsistencies, we need to check |
| 192 | * the result so that we'll get a timer that is monotonic. |
| 193 | */ |
| 194 | if (res >= USECS_PER_JIFFY) |
| 195 | res = USECS_PER_JIFFY - 1; |
| 196 | |
| 197 | return res; |
| 198 | } |
| 199 | |
| 200 | |
| 201 | /* |
| 202 | * Cached "1/(clocks per usec) * 2^32" value. |
| 203 | * It has to be recalculated once each jiffy. |
| 204 | */ |
| 205 | static unsigned long cached_quotient; |
| 206 | |
| 207 | /* Last jiffy when calibrate_divXX_gettimeoffset() was called. */ |
| 208 | static unsigned long last_jiffies; |
| 209 | |
| 210 | /* |
| 211 | * This is moved from dec/time.c:do_ioasic_gettimeoffset() by Maciej. |
| 212 | */ |
| 213 | static unsigned long calibrate_div32_gettimeoffset(void) |
| 214 | { |
| 215 | u32 count; |
| 216 | unsigned long res, tmp; |
| 217 | unsigned long quotient; |
| 218 | |
| 219 | tmp = jiffies; |
| 220 | |
| 221 | quotient = cached_quotient; |
| 222 | |
| 223 | if (last_jiffies != tmp) { |
| 224 | last_jiffies = tmp; |
| 225 | if (last_jiffies != 0) { |
| 226 | unsigned long r0; |
| 227 | do_div64_32(r0, timerhi, timerlo, tmp); |
| 228 | do_div64_32(quotient, USECS_PER_JIFFY, |
| 229 | USECS_PER_JIFFY_FRAC, r0); |
| 230 | cached_quotient = quotient; |
| 231 | } |
| 232 | } |
| 233 | |
| 234 | /* Get last timer tick in absolute kernel time */ |
| 235 | count = mips_hpt_read(); |
| 236 | |
| 237 | /* .. relative to previous jiffy (32 bits is enough) */ |
| 238 | count -= timerlo; |
| 239 | |
| 240 | __asm__("multu %1,%2" |
| 241 | : "=h" (res) |
| 242 | : "r" (count), "r" (quotient) |
| 243 | : "lo", GCC_REG_ACCUM); |
| 244 | |
| 245 | /* |
| 246 | * Due to possible jiffies inconsistencies, we need to check |
| 247 | * the result so that we'll get a timer that is monotonic. |
| 248 | */ |
| 249 | if (res >= USECS_PER_JIFFY) |
| 250 | res = USECS_PER_JIFFY - 1; |
| 251 | |
| 252 | return res; |
| 253 | } |
| 254 | |
| 255 | static unsigned long calibrate_div64_gettimeoffset(void) |
| 256 | { |
| 257 | u32 count; |
| 258 | unsigned long res, tmp; |
| 259 | unsigned long quotient; |
| 260 | |
| 261 | tmp = jiffies; |
| 262 | |
| 263 | quotient = cached_quotient; |
| 264 | |
| 265 | if (last_jiffies != tmp) { |
| 266 | last_jiffies = tmp; |
| 267 | if (last_jiffies) { |
| 268 | unsigned long r0; |
| 269 | __asm__(".set push\n\t" |
| 270 | ".set mips3\n\t" |
| 271 | "lwu %0,%3\n\t" |
| 272 | "dsll32 %1,%2,0\n\t" |
| 273 | "or %1,%1,%0\n\t" |
| 274 | "ddivu $0,%1,%4\n\t" |
| 275 | "mflo %1\n\t" |
| 276 | "dsll32 %0,%5,0\n\t" |
| 277 | "or %0,%0,%6\n\t" |
| 278 | "ddivu $0,%0,%1\n\t" |
| 279 | "mflo %0\n\t" |
| 280 | ".set pop" |
| 281 | : "=&r" (quotient), "=&r" (r0) |
| 282 | : "r" (timerhi), "m" (timerlo), |
| 283 | "r" (tmp), "r" (USECS_PER_JIFFY), |
| 284 | "r" (USECS_PER_JIFFY_FRAC) |
| 285 | : "hi", "lo", GCC_REG_ACCUM); |
| 286 | cached_quotient = quotient; |
| 287 | } |
| 288 | } |
| 289 | |
| 290 | /* Get last timer tick in absolute kernel time */ |
| 291 | count = mips_hpt_read(); |
| 292 | |
| 293 | /* .. relative to previous jiffy (32 bits is enough) */ |
| 294 | count -= timerlo; |
| 295 | |
| 296 | __asm__("multu %1,%2" |
| 297 | : "=h" (res) |
| 298 | : "r" (count), "r" (quotient) |
| 299 | : "lo", GCC_REG_ACCUM); |
| 300 | |
| 301 | /* |
| 302 | * Due to possible jiffies inconsistencies, we need to check |
| 303 | * the result so that we'll get a timer that is monotonic. |
| 304 | */ |
| 305 | if (res >= USECS_PER_JIFFY) |
| 306 | res = USECS_PER_JIFFY - 1; |
| 307 | |
| 308 | return res; |
| 309 | } |
| 310 | |
| 311 | |
| 312 | /* last time when xtime and rtc are sync'ed up */ |
| 313 | static long last_rtc_update; |
| 314 | |
| 315 | /* |
| 316 | * local_timer_interrupt() does profiling and process accounting |
| 317 | * on a per-CPU basis. |
| 318 | * |
| 319 | * In UP mode, it is invoked from the (global) timer_interrupt. |
| 320 | * |
| 321 | * In SMP mode, it might invoked by per-CPU timer interrupt, or |
| 322 | * a broadcasted inter-processor interrupt which itself is triggered |
| 323 | * by the global timer interrupt. |
| 324 | */ |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame^] | 325 | void local_timer_interrupt(int irq, void *dev_id) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 326 | { |
| 327 | if (current->pid) |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame^] | 328 | profile_tick(CPU_PROFILING); |
| 329 | update_process_times(user_mode(get_irq_regs())); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 330 | } |
| 331 | |
| 332 | /* |
| 333 | * High-level timer interrupt service routines. This function |
| 334 | * is set as irqaction->handler and is invoked through do_IRQ. |
| 335 | */ |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame^] | 336 | irqreturn_t timer_interrupt(int irq, void *dev_id) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 337 | { |
| 338 | unsigned long j; |
| 339 | unsigned int count; |
| 340 | |
Ralf Baechle | d6bd0e6 | 2006-03-14 23:46:58 +0000 | [diff] [blame] | 341 | write_seqlock(&xtime_lock); |
| 342 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 343 | count = mips_hpt_read(); |
| 344 | mips_timer_ack(); |
| 345 | |
| 346 | /* Update timerhi/timerlo for intra-jiffy calibration. */ |
| 347 | timerhi += count < timerlo; /* Wrap around */ |
| 348 | timerlo = count; |
| 349 | |
| 350 | /* |
| 351 | * call the generic timer interrupt handling |
| 352 | */ |
Atsushi Nemoto | 3171a03 | 2006-09-29 02:00:32 -0700 | [diff] [blame] | 353 | do_timer(1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 354 | |
| 355 | /* |
| 356 | * If we have an externally synchronized Linux clock, then update |
Yoichi Yuasa | d23ee8f | 2006-03-27 01:16:33 -0800 | [diff] [blame] | 357 | * CMOS clock accordingly every ~11 minutes. rtc_mips_set_time() has to be |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 358 | * called as close as possible to 500 ms before the new second starts. |
| 359 | */ |
john stultz | b149ee2 | 2005-09-06 15:17:46 -0700 | [diff] [blame] | 360 | if (ntp_synced() && |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 361 | xtime.tv_sec > last_rtc_update + 660 && |
| 362 | (xtime.tv_nsec / 1000) >= 500000 - ((unsigned) TICK_SIZE) / 2 && |
| 363 | (xtime.tv_nsec / 1000) <= 500000 + ((unsigned) TICK_SIZE) / 2) { |
Yoichi Yuasa | d23ee8f | 2006-03-27 01:16:33 -0800 | [diff] [blame] | 364 | if (rtc_mips_set_mmss(xtime.tv_sec) == 0) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 365 | last_rtc_update = xtime.tv_sec; |
| 366 | } else { |
| 367 | /* do it again in 60 s */ |
| 368 | last_rtc_update = xtime.tv_sec - 600; |
| 369 | } |
| 370 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 371 | |
| 372 | /* |
| 373 | * If jiffies has overflown in this timer_interrupt, we must |
| 374 | * update the timer[hi]/[lo] to make fast gettimeoffset funcs |
| 375 | * quotient calc still valid. -arca |
| 376 | * |
| 377 | * The first timer interrupt comes late as interrupts are |
| 378 | * enabled long after timers are initialized. Therefore the |
| 379 | * high precision timer is fast, leading to wrong gettimeoffset() |
| 380 | * calculations. We deal with it by setting it based on the |
| 381 | * number of its ticks between the second and the third interrupt. |
| 382 | * That is still somewhat imprecise, but it's a good estimate. |
| 383 | * --macro |
| 384 | */ |
| 385 | j = jiffies; |
| 386 | if (j < 4) { |
| 387 | static unsigned int prev_count; |
| 388 | static int hpt_initialized; |
| 389 | |
| 390 | switch (j) { |
| 391 | case 0: |
| 392 | timerhi = timerlo = 0; |
| 393 | mips_hpt_init(count); |
| 394 | break; |
| 395 | case 2: |
| 396 | prev_count = count; |
| 397 | break; |
| 398 | case 3: |
| 399 | if (!hpt_initialized) { |
| 400 | unsigned int c3 = 3 * (count - prev_count); |
| 401 | |
| 402 | timerhi = 0; |
| 403 | timerlo = c3; |
| 404 | mips_hpt_init(count - c3); |
| 405 | hpt_initialized = 1; |
| 406 | } |
| 407 | break; |
| 408 | default: |
| 409 | break; |
| 410 | } |
| 411 | } |
| 412 | |
Ralf Baechle | d6bd0e6 | 2006-03-14 23:46:58 +0000 | [diff] [blame] | 413 | write_sequnlock(&xtime_lock); |
| 414 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 415 | /* |
| 416 | * In UP mode, we call local_timer_interrupt() to do profiling |
| 417 | * and process accouting. |
| 418 | * |
| 419 | * In SMP mode, local_timer_interrupt() is invoked by appropriate |
| 420 | * low-level local timer interrupt handler. |
| 421 | */ |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame^] | 422 | local_timer_interrupt(irq, dev_id); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 423 | |
| 424 | return IRQ_HANDLED; |
| 425 | } |
| 426 | |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame^] | 427 | int null_perf_irq(void) |
Ralf Baechle | ba339c0 | 2005-12-09 12:29:38 +0000 | [diff] [blame] | 428 | { |
| 429 | return 0; |
| 430 | } |
| 431 | |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame^] | 432 | int (*perf_irq)(void) = null_perf_irq; |
Ralf Baechle | ba339c0 | 2005-12-09 12:29:38 +0000 | [diff] [blame] | 433 | |
| 434 | EXPORT_SYMBOL(null_perf_irq); |
| 435 | EXPORT_SYMBOL(perf_irq); |
| 436 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 437 | asmlinkage void ll_timer_interrupt(int irq, struct pt_regs *regs) |
| 438 | { |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame^] | 439 | struct pt_regs *old_regs = set_irq_regs(regs); |
Ralf Baechle | ba339c0 | 2005-12-09 12:29:38 +0000 | [diff] [blame] | 440 | int r2 = cpu_has_mips_r2; |
| 441 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 442 | irq_enter(); |
| 443 | kstat_this_cpu.irqs[irq]++; |
| 444 | |
Ralf Baechle | ba339c0 | 2005-12-09 12:29:38 +0000 | [diff] [blame] | 445 | /* |
| 446 | * Suckage alert: |
| 447 | * Before R2 of the architecture there was no way to see if a |
| 448 | * performance counter interrupt was pending, so we have to run the |
| 449 | * performance counter interrupt handler anyway. |
| 450 | */ |
| 451 | if (!r2 || (read_c0_cause() & (1 << 26))) |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame^] | 452 | if (perf_irq()) |
Ralf Baechle | ba339c0 | 2005-12-09 12:29:38 +0000 | [diff] [blame] | 453 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 454 | |
Ralf Baechle | ba339c0 | 2005-12-09 12:29:38 +0000 | [diff] [blame] | 455 | /* we keep interrupt disabled all the time */ |
| 456 | if (!r2 || (read_c0_cause() & (1 << 30))) |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame^] | 457 | timer_interrupt(irq, NULL); |
Ralf Baechle | ba339c0 | 2005-12-09 12:29:38 +0000 | [diff] [blame] | 458 | |
| 459 | out: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 460 | irq_exit(); |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame^] | 461 | set_irq_regs(old_regs); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 462 | } |
| 463 | |
| 464 | asmlinkage void ll_local_timer_interrupt(int irq, struct pt_regs *regs) |
| 465 | { |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame^] | 466 | struct pt_regs *old_regs = set_irq_regs(regs); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 467 | irq_enter(); |
| 468 | if (smp_processor_id() != 0) |
| 469 | kstat_this_cpu.irqs[irq]++; |
| 470 | |
| 471 | /* we keep interrupt disabled all the time */ |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame^] | 472 | local_timer_interrupt(irq, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 473 | |
| 474 | irq_exit(); |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame^] | 475 | set_irq_regs(old_regs); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 476 | } |
| 477 | |
| 478 | /* |
| 479 | * time_init() - it does the following things. |
| 480 | * |
| 481 | * 1) board_time_init() - |
| 482 | * a) (optional) set up RTC routines, |
| 483 | * b) (optional) calibrate and set the mips_hpt_frequency |
| 484 | * (only needed if you intended to use fixed_rate_gettimeoffset |
| 485 | * or use cpu counter as timer interrupt source) |
Yoichi Yuasa | d23ee8f | 2006-03-27 01:16:33 -0800 | [diff] [blame] | 486 | * 2) setup xtime based on rtc_mips_get_time(). |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 487 | * 3) choose a appropriate gettimeoffset routine. |
| 488 | * 4) calculate a couple of cached variables for later usage |
Ralf Baechle | 54d0a21 | 2006-07-09 21:38:56 +0100 | [diff] [blame] | 489 | * 5) plat_timer_setup() - |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 490 | * a) (optional) over-write any choices made above by time_init(). |
| 491 | * b) machine specific code should setup the timer irqaction. |
| 492 | * c) enable the timer interrupt |
| 493 | */ |
| 494 | |
| 495 | void (*board_time_init)(void); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 496 | |
| 497 | unsigned int mips_hpt_frequency; |
| 498 | |
| 499 | static struct irqaction timer_irqaction = { |
| 500 | .handler = timer_interrupt, |
Thomas Gleixner | f40298f | 2006-07-01 19:29:20 -0700 | [diff] [blame] | 501 | .flags = IRQF_DISABLED, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 502 | .name = "timer", |
| 503 | }; |
| 504 | |
| 505 | static unsigned int __init calibrate_hpt(void) |
| 506 | { |
| 507 | u64 frequency; |
| 508 | u32 hpt_start, hpt_end, hpt_count, hz; |
| 509 | |
| 510 | const int loops = HZ / 10; |
| 511 | int log_2_loops = 0; |
| 512 | int i; |
| 513 | |
| 514 | /* |
| 515 | * We want to calibrate for 0.1s, but to avoid a 64-bit |
| 516 | * division we round the number of loops up to the nearest |
| 517 | * power of 2. |
| 518 | */ |
| 519 | while (loops > 1 << log_2_loops) |
| 520 | log_2_loops++; |
| 521 | i = 1 << log_2_loops; |
| 522 | |
| 523 | /* |
| 524 | * Wait for a rising edge of the timer interrupt. |
| 525 | */ |
| 526 | while (mips_timer_state()); |
| 527 | while (!mips_timer_state()); |
| 528 | |
| 529 | /* |
| 530 | * Now see how many high precision timer ticks happen |
| 531 | * during the calculated number of periods between timer |
| 532 | * interrupts. |
| 533 | */ |
| 534 | hpt_start = mips_hpt_read(); |
| 535 | do { |
| 536 | while (mips_timer_state()); |
| 537 | while (!mips_timer_state()); |
| 538 | } while (--i); |
| 539 | hpt_end = mips_hpt_read(); |
| 540 | |
| 541 | hpt_count = hpt_end - hpt_start; |
| 542 | hz = HZ; |
| 543 | frequency = (u64)hpt_count * (u64)hz; |
| 544 | |
| 545 | return frequency >> log_2_loops; |
| 546 | } |
| 547 | |
| 548 | void __init time_init(void) |
| 549 | { |
| 550 | if (board_time_init) |
| 551 | board_time_init(); |
| 552 | |
Yoichi Yuasa | d23ee8f | 2006-03-27 01:16:33 -0800 | [diff] [blame] | 553 | if (!rtc_mips_set_mmss) |
| 554 | rtc_mips_set_mmss = rtc_mips_set_time; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 555 | |
Yoichi Yuasa | d23ee8f | 2006-03-27 01:16:33 -0800 | [diff] [blame] | 556 | xtime.tv_sec = rtc_mips_get_time(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 557 | xtime.tv_nsec = 0; |
| 558 | |
| 559 | set_normalized_timespec(&wall_to_monotonic, |
| 560 | -xtime.tv_sec, -xtime.tv_nsec); |
| 561 | |
| 562 | /* Choose appropriate high precision timer routines. */ |
| 563 | if (!cpu_has_counter && !mips_hpt_read) { |
| 564 | /* No high precision timer -- sorry. */ |
| 565 | mips_hpt_read = null_hpt_read; |
| 566 | mips_hpt_init = null_hpt_init; |
| 567 | } else if (!mips_hpt_frequency && !mips_timer_state) { |
| 568 | /* A high precision timer of unknown frequency. */ |
| 569 | if (!mips_hpt_read) { |
| 570 | /* No external high precision timer -- use R4k. */ |
| 571 | mips_hpt_read = c0_hpt_read; |
| 572 | mips_hpt_init = c0_hpt_init; |
| 573 | } |
| 574 | |
Ralf Baechle | b4672d3 | 2005-12-08 14:04:24 +0000 | [diff] [blame] | 575 | if (cpu_has_mips32r1 || cpu_has_mips32r2 || |
| 576 | (current_cpu_data.isa_level == MIPS_CPU_ISA_I) || |
| 577 | (current_cpu_data.isa_level == MIPS_CPU_ISA_II)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 578 | /* |
| 579 | * We need to calibrate the counter but we don't have |
| 580 | * 64-bit division. |
| 581 | */ |
| 582 | do_gettimeoffset = calibrate_div32_gettimeoffset; |
| 583 | else |
| 584 | /* |
| 585 | * We need to calibrate the counter but we *do* have |
| 586 | * 64-bit division. |
| 587 | */ |
| 588 | do_gettimeoffset = calibrate_div64_gettimeoffset; |
| 589 | } else { |
| 590 | /* We know counter frequency. Or we can get it. */ |
| 591 | if (!mips_hpt_read) { |
| 592 | /* No external high precision timer -- use R4k. */ |
| 593 | mips_hpt_read = c0_hpt_read; |
| 594 | |
| 595 | if (mips_timer_state) |
| 596 | mips_hpt_init = c0_hpt_init; |
| 597 | else { |
| 598 | /* No external timer interrupt -- use R4k. */ |
| 599 | mips_hpt_init = c0_hpt_timer_init; |
| 600 | mips_timer_ack = c0_timer_ack; |
| 601 | } |
| 602 | } |
| 603 | if (!mips_hpt_frequency) |
| 604 | mips_hpt_frequency = calibrate_hpt(); |
| 605 | |
| 606 | do_gettimeoffset = fixed_rate_gettimeoffset; |
| 607 | |
| 608 | /* Calculate cache parameters. */ |
| 609 | cycles_per_jiffy = (mips_hpt_frequency + HZ / 2) / HZ; |
| 610 | |
| 611 | /* sll32_usecs_per_cycle = 10^6 * 2^32 / mips_counter_freq */ |
| 612 | do_div64_32(sll32_usecs_per_cycle, |
| 613 | 1000000, mips_hpt_frequency / 2, |
| 614 | mips_hpt_frequency); |
| 615 | |
| 616 | /* Report the high precision timer rate for a reference. */ |
| 617 | printk("Using %u.%03u MHz high precision timer.\n", |
| 618 | ((mips_hpt_frequency + 500) / 1000) / 1000, |
| 619 | ((mips_hpt_frequency + 500) / 1000) % 1000); |
| 620 | } |
| 621 | |
| 622 | if (!mips_timer_ack) |
| 623 | /* No timer interrupt ack (e.g. i8254). */ |
| 624 | mips_timer_ack = null_timer_ack; |
| 625 | |
| 626 | /* This sets up the high precision timer for the first interrupt. */ |
| 627 | mips_hpt_init(mips_hpt_read()); |
| 628 | |
| 629 | /* |
| 630 | * Call board specific timer interrupt setup. |
| 631 | * |
| 632 | * this pointer must be setup in machine setup routine. |
| 633 | * |
| 634 | * Even if a machine chooses to use a low-level timer interrupt, |
| 635 | * it still needs to setup the timer_irqaction. |
| 636 | * In that case, it might be better to set timer_irqaction.handler |
| 637 | * to be NULL function so that we are sure the high-level code |
| 638 | * is not invoked accidentally. |
| 639 | */ |
Ralf Baechle | 54d0a21 | 2006-07-09 21:38:56 +0100 | [diff] [blame] | 640 | plat_timer_setup(&timer_irqaction); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 641 | } |
| 642 | |
| 643 | #define FEBRUARY 2 |
| 644 | #define STARTOFTIME 1970 |
| 645 | #define SECDAY 86400L |
| 646 | #define SECYR (SECDAY * 365) |
| 647 | #define leapyear(y) ((!((y) % 4) && ((y) % 100)) || !((y) % 400)) |
| 648 | #define days_in_year(y) (leapyear(y) ? 366 : 365) |
| 649 | #define days_in_month(m) (month_days[(m) - 1]) |
| 650 | |
| 651 | static int month_days[12] = { |
| 652 | 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 |
| 653 | }; |
| 654 | |
| 655 | void to_tm(unsigned long tim, struct rtc_time *tm) |
| 656 | { |
| 657 | long hms, day, gday; |
| 658 | int i; |
| 659 | |
| 660 | gday = day = tim / SECDAY; |
| 661 | hms = tim % SECDAY; |
| 662 | |
| 663 | /* Hours, minutes, seconds are easy */ |
| 664 | tm->tm_hour = hms / 3600; |
| 665 | tm->tm_min = (hms % 3600) / 60; |
| 666 | tm->tm_sec = (hms % 3600) % 60; |
| 667 | |
| 668 | /* Number of years in days */ |
| 669 | for (i = STARTOFTIME; day >= days_in_year(i); i++) |
| 670 | day -= days_in_year(i); |
| 671 | tm->tm_year = i; |
| 672 | |
| 673 | /* Number of months in days left */ |
| 674 | if (leapyear(tm->tm_year)) |
| 675 | days_in_month(FEBRUARY) = 29; |
| 676 | for (i = 1; day >= days_in_month(i); i++) |
| 677 | day -= days_in_month(i); |
| 678 | days_in_month(FEBRUARY) = 28; |
| 679 | tm->tm_mon = i - 1; /* tm_mon starts from 0 to 11 */ |
| 680 | |
| 681 | /* Days are what is left over (+1) from all that. */ |
| 682 | tm->tm_mday = day + 1; |
| 683 | |
| 684 | /* |
| 685 | * Determine the day of week |
| 686 | */ |
| 687 | tm->tm_wday = (gday + 4) % 7; /* 1970/1/1 was Thursday */ |
| 688 | } |
| 689 | |
| 690 | EXPORT_SYMBOL(rtc_lock); |
| 691 | EXPORT_SYMBOL(to_tm); |
Yoichi Yuasa | d23ee8f | 2006-03-27 01:16:33 -0800 | [diff] [blame] | 692 | EXPORT_SYMBOL(rtc_mips_set_time); |
| 693 | EXPORT_SYMBOL(rtc_mips_get_time); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 694 | |
| 695 | unsigned long long sched_clock(void) |
| 696 | { |
| 697 | return (unsigned long long)jiffies*(1000000000/HZ); |
| 698 | } |