Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/arch/x86-64/kernel/time.c |
| 3 | * |
| 4 | * "High Precision Event Timer" based timekeeping. |
| 5 | * |
| 6 | * Copyright (c) 1991,1992,1995 Linus Torvalds |
| 7 | * Copyright (c) 1994 Alan Modra |
| 8 | * Copyright (c) 1995 Markus Kuhn |
| 9 | * Copyright (c) 1996 Ingo Molnar |
| 10 | * Copyright (c) 1998 Andrea Arcangeli |
Vojtech Pavlik | 2f82bde4 | 2006-06-26 13:58:38 +0200 | [diff] [blame] | 11 | * Copyright (c) 2002,2006 Vojtech Pavlik |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 12 | * Copyright (c) 2003 Andi Kleen |
| 13 | * RTC support code taken from arch/i386/kernel/timers/time_hpet.c |
| 14 | */ |
| 15 | |
| 16 | #include <linux/kernel.h> |
| 17 | #include <linux/sched.h> |
| 18 | #include <linux/interrupt.h> |
| 19 | #include <linux/init.h> |
| 20 | #include <linux/mc146818rtc.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 21 | #include <linux/time.h> |
| 22 | #include <linux/ioport.h> |
| 23 | #include <linux/module.h> |
| 24 | #include <linux/device.h> |
| 25 | #include <linux/sysdev.h> |
| 26 | #include <linux/bcd.h> |
Vojtech Pavlik | a670fad | 2006-09-26 10:52:28 +0200 | [diff] [blame] | 27 | #include <linux/notifier.h> |
| 28 | #include <linux/cpu.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 29 | #include <linux/kallsyms.h> |
Andi Kleen | 312df5f | 2005-05-16 21:53:28 -0700 | [diff] [blame] | 30 | #include <linux/acpi.h> |
Andi Kleen | 8d91640 | 2005-05-31 14:39:26 -0700 | [diff] [blame] | 31 | #ifdef CONFIG_ACPI |
Andi Kleen | 312df5f | 2005-05-16 21:53:28 -0700 | [diff] [blame] | 32 | #include <acpi/achware.h> /* for PM timer frequency */ |
Andi Kleen | 0e5f61b | 2006-07-29 21:42:37 +0200 | [diff] [blame] | 33 | #include <acpi/acpi_bus.h> |
Andi Kleen | 8d91640 | 2005-05-31 14:39:26 -0700 | [diff] [blame] | 34 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 35 | #include <asm/8253pit.h> |
| 36 | #include <asm/pgtable.h> |
| 37 | #include <asm/vsyscall.h> |
| 38 | #include <asm/timex.h> |
| 39 | #include <asm/proto.h> |
| 40 | #include <asm/hpet.h> |
| 41 | #include <asm/sections.h> |
| 42 | #include <linux/cpufreq.h> |
| 43 | #include <linux/hpet.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 44 | #include <asm/apic.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 45 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 46 | #ifdef CONFIG_CPU_FREQ |
| 47 | static void cpufreq_delayed_get(void); |
| 48 | #endif |
| 49 | extern void i8254_timer_resume(void); |
| 50 | extern int using_apic_timer; |
| 51 | |
Vojtech Pavlik | a670fad | 2006-09-26 10:52:28 +0200 | [diff] [blame] | 52 | static char *timename = NULL; |
Andi Kleen | e8b9177 | 2006-02-26 04:18:49 +0100 | [diff] [blame] | 53 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 54 | DEFINE_SPINLOCK(rtc_lock); |
Andi Kleen | 2ee60e17 | 2006-06-26 13:59:44 +0200 | [diff] [blame] | 55 | EXPORT_SYMBOL(rtc_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 56 | DEFINE_SPINLOCK(i8253_lock); |
| 57 | |
Andi Kleen | 73dea47 | 2006-02-03 21:50:50 +0100 | [diff] [blame] | 58 | int nohpet __initdata = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 59 | static int notsc __initdata = 0; |
| 60 | |
Vojtech Pavlik | 4221133 | 2006-06-26 13:58:32 +0200 | [diff] [blame] | 61 | #define USEC_PER_TICK (USEC_PER_SEC / HZ) |
| 62 | #define NSEC_PER_TICK (NSEC_PER_SEC / HZ) |
| 63 | #define FSEC_PER_TICK (FSEC_PER_SEC / HZ) |
| 64 | |
| 65 | #define NS_SCALE 10 /* 2^10, carefully chosen */ |
| 66 | #define US_SCALE 32 /* 2^32, arbitralrily chosen */ |
| 67 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 68 | unsigned int cpu_khz; /* TSC clocks / usec, not used here */ |
Andi Kleen | 2ee60e17 | 2006-06-26 13:59:44 +0200 | [diff] [blame] | 69 | EXPORT_SYMBOL(cpu_khz); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 70 | static unsigned long hpet_period; /* fsecs / HPET clock */ |
| 71 | unsigned long hpet_tick; /* HPET clocks / interrupt */ |
Chris McDermott | 33042a9 | 2006-02-11 17:55:50 -0800 | [diff] [blame] | 72 | int hpet_use_timer; /* Use counter of hpet for time keeping, otherwise PIT */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 73 | unsigned long vxtime_hz = PIT_TICK_RATE; |
| 74 | int report_lost_ticks; /* command line option */ |
| 75 | unsigned long long monotonic_base; |
| 76 | |
| 77 | struct vxtime_data __vxtime __section_vxtime; /* for vsyscalls */ |
| 78 | |
| 79 | volatile unsigned long __jiffies __section_jiffies = INITIAL_JIFFIES; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 80 | struct timespec __xtime __section_xtime; |
| 81 | struct timezone __sys_tz __section_sys_tz; |
| 82 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 83 | /* |
| 84 | * do_gettimeoffset() returns microseconds since last timer interrupt was |
| 85 | * triggered by hardware. A memory read of HPET is slower than a register read |
| 86 | * of TSC, but much more reliable. It's also synchronized to the timer |
| 87 | * interrupt. Note that do_gettimeoffset() may return more than hpet_tick, if a |
| 88 | * timer interrupt has happened already, but vxtime.trigger wasn't updated yet. |
| 89 | * This is not a problem, because jiffies hasn't updated either. They are bound |
| 90 | * together by xtime_lock. |
| 91 | */ |
| 92 | |
| 93 | static inline unsigned int do_gettimeoffset_tsc(void) |
| 94 | { |
| 95 | unsigned long t; |
| 96 | unsigned long x; |
Andi Kleen | c818a18 | 2006-01-11 22:45:24 +0100 | [diff] [blame] | 97 | t = get_cycles_sync(); |
Andi Kleen | 7351c0b | 2006-03-25 16:30:34 +0100 | [diff] [blame] | 98 | if (t < vxtime.last_tsc) |
| 99 | t = vxtime.last_tsc; /* hack */ |
Vojtech Pavlik | 4221133 | 2006-06-26 13:58:32 +0200 | [diff] [blame] | 100 | x = ((t - vxtime.last_tsc) * vxtime.tsc_quot) >> US_SCALE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 101 | return x; |
| 102 | } |
| 103 | |
| 104 | static inline unsigned int do_gettimeoffset_hpet(void) |
| 105 | { |
john stultz | a3a0075 | 2005-06-23 00:08:36 -0700 | [diff] [blame] | 106 | /* cap counter read to one tick to avoid inconsistencies */ |
| 107 | unsigned long counter = hpet_readl(HPET_COUNTER) - vxtime.last; |
Vojtech Pavlik | 4221133 | 2006-06-26 13:58:32 +0200 | [diff] [blame] | 108 | return (min(counter,hpet_tick) * vxtime.quot) >> US_SCALE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 109 | } |
| 110 | |
| 111 | unsigned int (*do_gettimeoffset)(void) = do_gettimeoffset_tsc; |
| 112 | |
| 113 | /* |
| 114 | * This version of gettimeofday() has microsecond resolution and better than |
| 115 | * microsecond precision, as we're using at least a 10 MHz (usually 14.31818 |
| 116 | * MHz) HPET timer. |
| 117 | */ |
| 118 | |
| 119 | void do_gettimeofday(struct timeval *tv) |
| 120 | { |
Atsushi Nemoto | 8ef3860 | 2006-09-30 23:28:31 -0700 | [diff] [blame] | 121 | unsigned long seq; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 122 | unsigned int sec, usec; |
| 123 | |
| 124 | do { |
| 125 | seq = read_seqbegin(&xtime_lock); |
| 126 | |
| 127 | sec = xtime.tv_sec; |
Vojtech Pavlik | 4221133 | 2006-06-26 13:58:32 +0200 | [diff] [blame] | 128 | usec = xtime.tv_nsec / NSEC_PER_USEC; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 129 | |
| 130 | /* i386 does some correction here to keep the clock |
| 131 | monotonous even when ntpd is fixing drift. |
| 132 | But they didn't work for me, there is a non monotonic |
| 133 | clock anyways with ntp. |
| 134 | I dropped all corrections now until a real solution can |
| 135 | be found. Note when you fix it here you need to do the same |
| 136 | in arch/x86_64/kernel/vsyscall.c and export all needed |
| 137 | variables in vmlinux.lds. -AK */ |
Atsushi Nemoto | 8ef3860 | 2006-09-30 23:28:31 -0700 | [diff] [blame] | 138 | usec += do_gettimeoffset(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 139 | |
| 140 | } while (read_seqretry(&xtime_lock, seq)); |
| 141 | |
Vojtech Pavlik | 4221133 | 2006-06-26 13:58:32 +0200 | [diff] [blame] | 142 | tv->tv_sec = sec + usec / USEC_PER_SEC; |
| 143 | tv->tv_usec = usec % USEC_PER_SEC; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 144 | } |
| 145 | |
| 146 | EXPORT_SYMBOL(do_gettimeofday); |
| 147 | |
| 148 | /* |
| 149 | * settimeofday() first undoes the correction that gettimeofday would do |
| 150 | * on the time, and then saves it. This is ugly, but has been like this for |
| 151 | * ages already. |
| 152 | */ |
| 153 | |
| 154 | int do_settimeofday(struct timespec *tv) |
| 155 | { |
| 156 | time_t wtm_sec, sec = tv->tv_sec; |
| 157 | long wtm_nsec, nsec = tv->tv_nsec; |
| 158 | |
| 159 | if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC) |
| 160 | return -EINVAL; |
| 161 | |
| 162 | write_seqlock_irq(&xtime_lock); |
| 163 | |
Atsushi Nemoto | 8ef3860 | 2006-09-30 23:28:31 -0700 | [diff] [blame] | 164 | nsec -= do_gettimeoffset() * NSEC_PER_USEC; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 165 | |
| 166 | wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec); |
| 167 | wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec); |
| 168 | |
| 169 | set_normalized_timespec(&xtime, sec, nsec); |
| 170 | set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec); |
| 171 | |
john stultz | b149ee2 | 2005-09-06 15:17:46 -0700 | [diff] [blame] | 172 | ntp_clear(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 173 | |
| 174 | write_sequnlock_irq(&xtime_lock); |
| 175 | clock_was_set(); |
| 176 | return 0; |
| 177 | } |
| 178 | |
| 179 | EXPORT_SYMBOL(do_settimeofday); |
| 180 | |
| 181 | unsigned long profile_pc(struct pt_regs *regs) |
| 182 | { |
| 183 | unsigned long pc = instruction_pointer(regs); |
| 184 | |
Andi Kleen | 31679f3 | 2006-09-26 10:52:28 +0200 | [diff] [blame] | 185 | /* Assume the lock function has either no stack frame or a copy |
| 186 | of eflags from PUSHF |
| 187 | Eflags always has bits 22 and up cleared unlike kernel addresses. */ |
Andi Kleen | d5a2601 | 2006-07-28 14:44:42 +0200 | [diff] [blame] | 188 | if (!user_mode(regs) && in_lock_functions(pc)) { |
Andi Kleen | 31679f3 | 2006-09-26 10:52:28 +0200 | [diff] [blame] | 189 | unsigned long *sp = (unsigned long *)regs->rsp; |
| 190 | if (sp[0] >> 22) |
| 191 | return sp[0]; |
| 192 | if (sp[1] >> 22) |
| 193 | return sp[1]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 194 | } |
| 195 | return pc; |
| 196 | } |
| 197 | EXPORT_SYMBOL(profile_pc); |
| 198 | |
| 199 | /* |
| 200 | * In order to set the CMOS clock precisely, set_rtc_mmss has to be called 500 |
| 201 | * ms after the second nowtime has started, because when nowtime is written |
| 202 | * into the registers of the CMOS clock, it will jump to the next second |
| 203 | * precisely 500 ms later. Check the Motorola MC146818A or Dallas DS12887 data |
| 204 | * sheet for details. |
| 205 | */ |
| 206 | |
| 207 | static void set_rtc_mmss(unsigned long nowtime) |
| 208 | { |
| 209 | int real_seconds, real_minutes, cmos_minutes; |
| 210 | unsigned char control, freq_select; |
| 211 | |
| 212 | /* |
| 213 | * IRQs are disabled when we're called from the timer interrupt, |
| 214 | * no need for spin_lock_irqsave() |
| 215 | */ |
| 216 | |
| 217 | spin_lock(&rtc_lock); |
| 218 | |
| 219 | /* |
| 220 | * Tell the clock it's being set and stop it. |
| 221 | */ |
| 222 | |
| 223 | control = CMOS_READ(RTC_CONTROL); |
| 224 | CMOS_WRITE(control | RTC_SET, RTC_CONTROL); |
| 225 | |
| 226 | freq_select = CMOS_READ(RTC_FREQ_SELECT); |
| 227 | CMOS_WRITE(freq_select | RTC_DIV_RESET2, RTC_FREQ_SELECT); |
| 228 | |
| 229 | cmos_minutes = CMOS_READ(RTC_MINUTES); |
| 230 | BCD_TO_BIN(cmos_minutes); |
| 231 | |
| 232 | /* |
| 233 | * since we're only adjusting minutes and seconds, don't interfere with hour |
| 234 | * overflow. This avoids messing with unknown time zones but requires your RTC |
| 235 | * not to be off by more than 15 minutes. Since we're calling it only when |
| 236 | * our clock is externally synchronized using NTP, this shouldn't be a problem. |
| 237 | */ |
| 238 | |
| 239 | real_seconds = nowtime % 60; |
| 240 | real_minutes = nowtime / 60; |
| 241 | if (((abs(real_minutes - cmos_minutes) + 15) / 30) & 1) |
| 242 | real_minutes += 30; /* correct for half hour time zone */ |
| 243 | real_minutes %= 60; |
| 244 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 245 | if (abs(real_minutes - cmos_minutes) >= 30) { |
| 246 | printk(KERN_WARNING "time.c: can't update CMOS clock " |
| 247 | "from %d to %d\n", cmos_minutes, real_minutes); |
Andi Kleen | 28456ed | 2006-03-25 16:30:37 +0100 | [diff] [blame] | 248 | } else { |
Andi Kleen | 0b91317 | 2006-01-11 22:45:33 +0100 | [diff] [blame] | 249 | BIN_TO_BCD(real_seconds); |
| 250 | BIN_TO_BCD(real_minutes); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 251 | CMOS_WRITE(real_seconds, RTC_SECONDS); |
| 252 | CMOS_WRITE(real_minutes, RTC_MINUTES); |
| 253 | } |
| 254 | |
| 255 | /* |
| 256 | * The following flags have to be released exactly in this order, otherwise the |
| 257 | * DS12887 (popular MC146818A clone with integrated battery and quartz) will |
| 258 | * not reset the oscillator and will not update precisely 500 ms later. You |
| 259 | * won't find this mentioned in the Dallas Semiconductor data sheets, but who |
| 260 | * believes data sheets anyway ... -- Markus Kuhn |
| 261 | */ |
| 262 | |
| 263 | CMOS_WRITE(control, RTC_CONTROL); |
| 264 | CMOS_WRITE(freq_select, RTC_FREQ_SELECT); |
| 265 | |
| 266 | spin_unlock(&rtc_lock); |
| 267 | } |
| 268 | |
| 269 | |
| 270 | /* monotonic_clock(): returns # of nanoseconds passed since time_init() |
| 271 | * Note: This function is required to return accurate |
| 272 | * time even in the absence of multiple timer ticks. |
| 273 | */ |
Dimitri Sivanich | cbf9b4b | 2006-09-26 10:52:34 +0200 | [diff] [blame] | 274 | static inline unsigned long long cycles_2_ns(unsigned long long cyc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 275 | unsigned long long monotonic_clock(void) |
| 276 | { |
| 277 | unsigned long seq; |
| 278 | u32 last_offset, this_offset, offset; |
| 279 | unsigned long long base; |
| 280 | |
| 281 | if (vxtime.mode == VXTIME_HPET) { |
| 282 | do { |
| 283 | seq = read_seqbegin(&xtime_lock); |
| 284 | |
| 285 | last_offset = vxtime.last; |
| 286 | base = monotonic_base; |
john stultz | a3a0075 | 2005-06-23 00:08:36 -0700 | [diff] [blame] | 287 | this_offset = hpet_readl(HPET_COUNTER); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 288 | } while (read_seqretry(&xtime_lock, seq)); |
| 289 | offset = (this_offset - last_offset); |
Vojtech Pavlik | 4221133 | 2006-06-26 13:58:32 +0200 | [diff] [blame] | 290 | offset *= NSEC_PER_TICK / hpet_tick; |
Andi Kleen | 0b91317 | 2006-01-11 22:45:33 +0100 | [diff] [blame] | 291 | } else { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 292 | do { |
| 293 | seq = read_seqbegin(&xtime_lock); |
| 294 | |
| 295 | last_offset = vxtime.last_tsc; |
| 296 | base = monotonic_base; |
| 297 | } while (read_seqretry(&xtime_lock, seq)); |
Andi Kleen | c818a18 | 2006-01-11 22:45:24 +0100 | [diff] [blame] | 298 | this_offset = get_cycles_sync(); |
Dimitri Sivanich | cbf9b4b | 2006-09-26 10:52:34 +0200 | [diff] [blame] | 299 | offset = cycles_2_ns(this_offset - last_offset); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 300 | } |
Andi Kleen | 7351c0b | 2006-03-25 16:30:34 +0100 | [diff] [blame] | 301 | return base + offset; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 302 | } |
| 303 | EXPORT_SYMBOL(monotonic_clock); |
| 304 | |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 305 | static noinline void handle_lost_ticks(int lost) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 306 | { |
Andi Kleen | 7351c0b | 2006-03-25 16:30:34 +0100 | [diff] [blame] | 307 | static long lost_count; |
| 308 | static int warned; |
| 309 | if (report_lost_ticks) { |
| 310 | printk(KERN_WARNING "time.c: Lost %d timer tick(s)! ", lost); |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 311 | print_symbol("rip %s)\n", get_irq_regs()->rip); |
Andi Kleen | 7351c0b | 2006-03-25 16:30:34 +0100 | [diff] [blame] | 312 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 313 | |
Andi Kleen | 7351c0b | 2006-03-25 16:30:34 +0100 | [diff] [blame] | 314 | if (lost_count == 1000 && !warned) { |
| 315 | printk(KERN_WARNING "warning: many lost ticks.\n" |
| 316 | KERN_WARNING "Your time source seems to be instable or " |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 317 | "some driver is hogging interupts\n"); |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 318 | print_symbol("rip %s\n", get_irq_regs()->rip); |
Andi Kleen | 7351c0b | 2006-03-25 16:30:34 +0100 | [diff] [blame] | 319 | if (vxtime.mode == VXTIME_TSC && vxtime.hpet_address) { |
| 320 | printk(KERN_WARNING "Falling back to HPET\n"); |
| 321 | if (hpet_use_timer) |
| 322 | vxtime.last = hpet_readl(HPET_T0_CMP) - |
| 323 | hpet_tick; |
| 324 | else |
| 325 | vxtime.last = hpet_readl(HPET_COUNTER); |
| 326 | vxtime.mode = VXTIME_HPET; |
| 327 | do_gettimeoffset = do_gettimeoffset_hpet; |
| 328 | } |
| 329 | /* else should fall back to PIT, but code missing. */ |
| 330 | warned = 1; |
| 331 | } else |
| 332 | lost_count++; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 333 | |
| 334 | #ifdef CONFIG_CPU_FREQ |
Andi Kleen | 7351c0b | 2006-03-25 16:30:34 +0100 | [diff] [blame] | 335 | /* In some cases the CPU can change frequency without us noticing |
| 336 | Give cpufreq a change to catch up. */ |
| 337 | if ((lost_count+1) % 25 == 0) |
| 338 | cpufreq_delayed_get(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 339 | #endif |
| 340 | } |
| 341 | |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 342 | void main_timer_handler(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 343 | { |
| 344 | static unsigned long rtc_update = 0; |
| 345 | unsigned long tsc; |
Andi Kleen | 9ede6b0 | 2006-03-25 16:29:31 +0100 | [diff] [blame] | 346 | int delay = 0, offset = 0, lost = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 347 | |
| 348 | /* |
| 349 | * Here we are in the timer irq handler. We have irqs locally disabled (so we |
| 350 | * don't need spin_lock_irqsave()) but we don't know if the timer_bh is running |
| 351 | * on the other CPU, so we need a lock. We also need to lock the vsyscall |
| 352 | * variables, because both do_timer() and us change them -arca+vojtech |
| 353 | */ |
| 354 | |
| 355 | write_seqlock(&xtime_lock); |
| 356 | |
john stultz | a3a0075 | 2005-06-23 00:08:36 -0700 | [diff] [blame] | 357 | if (vxtime.hpet_address) |
| 358 | offset = hpet_readl(HPET_COUNTER); |
| 359 | |
| 360 | if (hpet_use_timer) { |
| 361 | /* if we're using the hpet timer functionality, |
| 362 | * we can more accurately know the counter value |
| 363 | * when the timer interrupt occured. |
| 364 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 365 | offset = hpet_readl(HPET_T0_CMP) - hpet_tick; |
| 366 | delay = hpet_readl(HPET_COUNTER) - offset; |
Andi Kleen | 9ede6b0 | 2006-03-25 16:29:31 +0100 | [diff] [blame] | 367 | } else if (!pmtmr_ioport) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 368 | spin_lock(&i8253_lock); |
| 369 | outb_p(0x00, 0x43); |
| 370 | delay = inb_p(0x40); |
| 371 | delay |= inb(0x40) << 8; |
| 372 | spin_unlock(&i8253_lock); |
| 373 | delay = LATCH - 1 - delay; |
| 374 | } |
| 375 | |
Andi Kleen | c818a18 | 2006-01-11 22:45:24 +0100 | [diff] [blame] | 376 | tsc = get_cycles_sync(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 377 | |
| 378 | if (vxtime.mode == VXTIME_HPET) { |
| 379 | if (offset - vxtime.last > hpet_tick) { |
| 380 | lost = (offset - vxtime.last) / hpet_tick - 1; |
| 381 | } |
| 382 | |
| 383 | monotonic_base += |
Vojtech Pavlik | 4221133 | 2006-06-26 13:58:32 +0200 | [diff] [blame] | 384 | (offset - vxtime.last) * NSEC_PER_TICK / hpet_tick; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 385 | |
| 386 | vxtime.last = offset; |
Andi Kleen | 312df5f | 2005-05-16 21:53:28 -0700 | [diff] [blame] | 387 | #ifdef CONFIG_X86_PM_TIMER |
| 388 | } else if (vxtime.mode == VXTIME_PMTMR) { |
| 389 | lost = pmtimer_mark_offset(); |
| 390 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 391 | } else { |
| 392 | offset = (((tsc - vxtime.last_tsc) * |
Vojtech Pavlik | 4221133 | 2006-06-26 13:58:32 +0200 | [diff] [blame] | 393 | vxtime.tsc_quot) >> US_SCALE) - USEC_PER_TICK; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 394 | |
| 395 | if (offset < 0) |
| 396 | offset = 0; |
| 397 | |
Vojtech Pavlik | 4221133 | 2006-06-26 13:58:32 +0200 | [diff] [blame] | 398 | if (offset > USEC_PER_TICK) { |
| 399 | lost = offset / USEC_PER_TICK; |
| 400 | offset %= USEC_PER_TICK; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 401 | } |
| 402 | |
Dimitri Sivanich | cbf9b4b | 2006-09-26 10:52:34 +0200 | [diff] [blame] | 403 | monotonic_base += cycles_2_ns(tsc - vxtime.last_tsc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 404 | |
| 405 | vxtime.last_tsc = tsc - vxtime.quot * delay / vxtime.tsc_quot; |
| 406 | |
| 407 | if ((((tsc - vxtime.last_tsc) * |
Vojtech Pavlik | 4221133 | 2006-06-26 13:58:32 +0200 | [diff] [blame] | 408 | vxtime.tsc_quot) >> US_SCALE) < offset) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 409 | vxtime.last_tsc = tsc - |
Vojtech Pavlik | 4221133 | 2006-06-26 13:58:32 +0200 | [diff] [blame] | 410 | (((long) offset << US_SCALE) / vxtime.tsc_quot) - 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 411 | } |
| 412 | |
Atsushi Nemoto | 3171a03 | 2006-09-29 02:00:32 -0700 | [diff] [blame] | 413 | if (lost > 0) |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 414 | handle_lost_ticks(lost); |
Atsushi Nemoto | 3171a03 | 2006-09-29 02:00:32 -0700 | [diff] [blame] | 415 | else |
| 416 | lost = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 417 | |
| 418 | /* |
| 419 | * Do the timer stuff. |
| 420 | */ |
| 421 | |
Atsushi Nemoto | 3171a03 | 2006-09-29 02:00:32 -0700 | [diff] [blame] | 422 | do_timer(lost + 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 423 | #ifndef CONFIG_SMP |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 424 | update_process_times(user_mode(get_irq_regs())); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 425 | #endif |
| 426 | |
| 427 | /* |
| 428 | * In the SMP case we use the local APIC timer interrupt to do the profiling, |
| 429 | * except when we simulate SMP mode on a uniprocessor system, in that case we |
| 430 | * have to call the local interrupt handler. |
| 431 | */ |
| 432 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 433 | if (!using_apic_timer) |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 434 | smp_local_timer_interrupt(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 435 | |
| 436 | /* |
| 437 | * If we have an externally synchronized Linux clock, then update CMOS clock |
| 438 | * accordingly every ~11 minutes. set_rtc_mmss() will be called in the jiffy |
| 439 | * closest to exactly 500 ms before the next second. If the update fails, we |
| 440 | * don't care, as it'll be updated on the next turn, and the problem (time way |
| 441 | * off) isn't likely to go away much sooner anyway. |
| 442 | */ |
| 443 | |
john stultz | b149ee2 | 2005-09-06 15:17:46 -0700 | [diff] [blame] | 444 | if (ntp_synced() && xtime.tv_sec > rtc_update && |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 445 | abs(xtime.tv_nsec - 500000000) <= tick_nsec / 2) { |
| 446 | set_rtc_mmss(xtime.tv_sec); |
| 447 | rtc_update = xtime.tv_sec + 660; |
| 448 | } |
| 449 | |
| 450 | write_sequnlock(&xtime_lock); |
Andi Kleen | 73dea47 | 2006-02-03 21:50:50 +0100 | [diff] [blame] | 451 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 452 | |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 453 | static irqreturn_t timer_interrupt(int irq, void *dev_id) |
Andi Kleen | 73dea47 | 2006-02-03 21:50:50 +0100 | [diff] [blame] | 454 | { |
| 455 | if (apic_runs_main_timer > 1) |
| 456 | return IRQ_HANDLED; |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 457 | main_timer_handler(); |
Venkatesh Pallipadi | d25bf7e | 2006-01-11 22:44:24 +0100 | [diff] [blame] | 458 | if (using_apic_timer) |
| 459 | smp_send_timer_broadcast_ipi(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 460 | return IRQ_HANDLED; |
| 461 | } |
| 462 | |
Ravikiran G Thirumalai | 68ed004 | 2006-03-22 00:07:38 -0800 | [diff] [blame] | 463 | static unsigned int cyc2ns_scale __read_mostly; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 464 | |
Mathieu Desnoyers | dacb16b | 2005-10-30 14:59:25 -0800 | [diff] [blame] | 465 | static inline void set_cyc2ns_scale(unsigned long cpu_khz) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 466 | { |
Vojtech Pavlik | 4221133 | 2006-06-26 13:58:32 +0200 | [diff] [blame] | 467 | cyc2ns_scale = (NSEC_PER_MSEC << NS_SCALE) / cpu_khz; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 468 | } |
| 469 | |
| 470 | static inline unsigned long long cycles_2_ns(unsigned long long cyc) |
| 471 | { |
Vojtech Pavlik | 4221133 | 2006-06-26 13:58:32 +0200 | [diff] [blame] | 472 | return (cyc * cyc2ns_scale) >> NS_SCALE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 473 | } |
| 474 | |
| 475 | unsigned long long sched_clock(void) |
| 476 | { |
| 477 | unsigned long a = 0; |
| 478 | |
| 479 | #if 0 |
| 480 | /* Don't do a HPET read here. Using TSC always is much faster |
| 481 | and HPET may not be mapped yet when the scheduler first runs. |
| 482 | Disadvantage is a small drift between CPUs in some configurations, |
| 483 | but that should be tolerable. */ |
| 484 | if (__vxtime.mode == VXTIME_HPET) |
Vojtech Pavlik | 4221133 | 2006-06-26 13:58:32 +0200 | [diff] [blame] | 485 | return (hpet_readl(HPET_COUNTER) * vxtime.quot) >> US_SCALE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 486 | #endif |
| 487 | |
| 488 | /* Could do CPU core sync here. Opteron can execute rdtsc speculatively, |
| 489 | which means it is not completely exact and may not be monotonous between |
| 490 | CPUs. But the errors should be too small to matter for scheduling |
| 491 | purposes. */ |
| 492 | |
| 493 | rdtscll(a); |
| 494 | return cycles_2_ns(a); |
| 495 | } |
| 496 | |
Andi Kleen | bdf2b1c | 2006-01-11 22:46:39 +0100 | [diff] [blame] | 497 | static unsigned long get_cmos_time(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 498 | { |
Matt Mackall | 641f71f | 2006-03-28 01:56:01 -0800 | [diff] [blame] | 499 | unsigned int year, mon, day, hour, min, sec; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 500 | unsigned long flags; |
Alexey Starikovskiy | ad71860 | 2007-02-02 19:48:19 +0300 | [diff] [blame] | 501 | unsigned century = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 502 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 503 | spin_lock_irqsave(&rtc_lock, flags); |
| 504 | |
Matt Mackall | 641f71f | 2006-03-28 01:56:01 -0800 | [diff] [blame] | 505 | do { |
| 506 | sec = CMOS_READ(RTC_SECONDS); |
| 507 | min = CMOS_READ(RTC_MINUTES); |
| 508 | hour = CMOS_READ(RTC_HOURS); |
| 509 | day = CMOS_READ(RTC_DAY_OF_MONTH); |
| 510 | mon = CMOS_READ(RTC_MONTH); |
| 511 | year = CMOS_READ(RTC_YEAR); |
Andi Kleen | 6954bee | 2006-03-25 16:30:31 +0100 | [diff] [blame] | 512 | #ifdef CONFIG_ACPI |
Alexey Starikovskiy | ad71860 | 2007-02-02 19:48:19 +0300 | [diff] [blame] | 513 | if (acpi_gbl_FADT.header.revision >= FADT2_REVISION_ID && |
| 514 | acpi_gbl_FADT.century) |
| 515 | century = CMOS_READ(acpi_gbl_FADT.century); |
Andi Kleen | 6954bee | 2006-03-25 16:30:31 +0100 | [diff] [blame] | 516 | #endif |
Matt Mackall | 641f71f | 2006-03-28 01:56:01 -0800 | [diff] [blame] | 517 | } while (sec != CMOS_READ(RTC_SECONDS)); |
Andi Kleen | 6954bee | 2006-03-25 16:30:31 +0100 | [diff] [blame] | 518 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 519 | spin_unlock_irqrestore(&rtc_lock, flags); |
| 520 | |
Andi Kleen | 0b91317 | 2006-01-11 22:45:33 +0100 | [diff] [blame] | 521 | /* |
| 522 | * We know that x86-64 always uses BCD format, no need to check the |
| 523 | * config register. |
Andi Kleen | 7351c0b | 2006-03-25 16:30:34 +0100 | [diff] [blame] | 524 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 525 | |
Andi Kleen | 0b91317 | 2006-01-11 22:45:33 +0100 | [diff] [blame] | 526 | BCD_TO_BIN(sec); |
| 527 | BCD_TO_BIN(min); |
| 528 | BCD_TO_BIN(hour); |
| 529 | BCD_TO_BIN(day); |
| 530 | BCD_TO_BIN(mon); |
| 531 | BCD_TO_BIN(year); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 532 | |
Alexey Starikovskiy | ad71860 | 2007-02-02 19:48:19 +0300 | [diff] [blame] | 533 | if (century) { |
| 534 | BCD_TO_BIN(century); |
| 535 | year += century * 100; |
| 536 | printk(KERN_INFO "Extended CMOS year: %d\n", century * 100); |
Andi Kleen | 6954bee | 2006-03-25 16:30:31 +0100 | [diff] [blame] | 537 | } else { |
| 538 | /* |
| 539 | * x86-64 systems only exists since 2002. |
| 540 | * This will work up to Dec 31, 2100 |
| 541 | */ |
| 542 | year += 2000; |
| 543 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 544 | |
| 545 | return mktime(year, mon, day, hour, min, sec); |
| 546 | } |
| 547 | |
| 548 | #ifdef CONFIG_CPU_FREQ |
| 549 | |
| 550 | /* Frequency scaling support. Adjust the TSC based timer when the cpu frequency |
| 551 | changes. |
| 552 | |
| 553 | RED-PEN: On SMP we assume all CPUs run with the same frequency. It's |
| 554 | not that important because current Opteron setups do not support |
| 555 | scaling on SMP anyroads. |
| 556 | |
| 557 | Should fix up last_tsc too. Currently gettimeofday in the |
| 558 | first tick after the change will be slightly wrong. */ |
| 559 | |
| 560 | #include <linux/workqueue.h> |
| 561 | |
| 562 | static unsigned int cpufreq_delayed_issched = 0; |
| 563 | static unsigned int cpufreq_init = 0; |
| 564 | static struct work_struct cpufreq_delayed_get_work; |
| 565 | |
David Howells | 65f27f3 | 2006-11-22 14:55:48 +0000 | [diff] [blame] | 566 | static void handle_cpufreq_delayed_get(struct work_struct *v) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 567 | { |
| 568 | unsigned int cpu; |
| 569 | for_each_online_cpu(cpu) { |
| 570 | cpufreq_get(cpu); |
| 571 | } |
| 572 | cpufreq_delayed_issched = 0; |
| 573 | } |
| 574 | |
| 575 | /* if we notice lost ticks, schedule a call to cpufreq_get() as it tries |
| 576 | * to verify the CPU frequency the timing core thinks the CPU is running |
| 577 | * at is still correct. |
| 578 | */ |
| 579 | static void cpufreq_delayed_get(void) |
| 580 | { |
| 581 | static int warned; |
| 582 | if (cpufreq_init && !cpufreq_delayed_issched) { |
| 583 | cpufreq_delayed_issched = 1; |
| 584 | if (!warned) { |
| 585 | warned = 1; |
Andi Kleen | 7351c0b | 2006-03-25 16:30:34 +0100 | [diff] [blame] | 586 | printk(KERN_DEBUG |
| 587 | "Losing some ticks... checking if CPU frequency changed.\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 588 | } |
| 589 | schedule_work(&cpufreq_delayed_get_work); |
| 590 | } |
| 591 | } |
| 592 | |
| 593 | static unsigned int ref_freq = 0; |
| 594 | static unsigned long loops_per_jiffy_ref = 0; |
| 595 | |
| 596 | static unsigned long cpu_khz_ref = 0; |
| 597 | |
| 598 | static int time_cpufreq_notifier(struct notifier_block *nb, unsigned long val, |
| 599 | void *data) |
| 600 | { |
| 601 | struct cpufreq_freqs *freq = data; |
| 602 | unsigned long *lpj, dummy; |
| 603 | |
Andi Kleen | c29601e | 2005-04-16 15:25:05 -0700 | [diff] [blame] | 604 | if (cpu_has(&cpu_data[freq->cpu], X86_FEATURE_CONSTANT_TSC)) |
| 605 | return 0; |
| 606 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 607 | lpj = &dummy; |
| 608 | if (!(freq->flags & CPUFREQ_CONST_LOOPS)) |
| 609 | #ifdef CONFIG_SMP |
Andi Kleen | 7351c0b | 2006-03-25 16:30:34 +0100 | [diff] [blame] | 610 | lpj = &cpu_data[freq->cpu].loops_per_jiffy; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 611 | #else |
Andi Kleen | 7351c0b | 2006-03-25 16:30:34 +0100 | [diff] [blame] | 612 | lpj = &boot_cpu_data.loops_per_jiffy; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 613 | #endif |
| 614 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 615 | if (!ref_freq) { |
| 616 | ref_freq = freq->old; |
| 617 | loops_per_jiffy_ref = *lpj; |
| 618 | cpu_khz_ref = cpu_khz; |
| 619 | } |
| 620 | if ((val == CPUFREQ_PRECHANGE && freq->old < freq->new) || |
| 621 | (val == CPUFREQ_POSTCHANGE && freq->old > freq->new) || |
| 622 | (val == CPUFREQ_RESUMECHANGE)) { |
| 623 | *lpj = |
| 624 | cpufreq_scale(loops_per_jiffy_ref, ref_freq, freq->new); |
| 625 | |
| 626 | cpu_khz = cpufreq_scale(cpu_khz_ref, ref_freq, freq->new); |
| 627 | if (!(freq->flags & CPUFREQ_CONST_LOOPS)) |
Vojtech Pavlik | 4221133 | 2006-06-26 13:58:32 +0200 | [diff] [blame] | 628 | vxtime.tsc_quot = (USEC_PER_MSEC << US_SCALE) / cpu_khz; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 629 | } |
| 630 | |
Mathieu Desnoyers | dacb16b | 2005-10-30 14:59:25 -0800 | [diff] [blame] | 631 | set_cyc2ns_scale(cpu_khz_ref); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 632 | |
| 633 | return 0; |
| 634 | } |
| 635 | |
| 636 | static struct notifier_block time_cpufreq_notifier_block = { |
| 637 | .notifier_call = time_cpufreq_notifier |
| 638 | }; |
| 639 | |
| 640 | static int __init cpufreq_tsc(void) |
| 641 | { |
David Howells | 65f27f3 | 2006-11-22 14:55:48 +0000 | [diff] [blame] | 642 | INIT_WORK(&cpufreq_delayed_get_work, handle_cpufreq_delayed_get); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 643 | if (!cpufreq_register_notifier(&time_cpufreq_notifier_block, |
| 644 | CPUFREQ_TRANSITION_NOTIFIER)) |
| 645 | cpufreq_init = 1; |
| 646 | return 0; |
| 647 | } |
| 648 | |
| 649 | core_initcall(cpufreq_tsc); |
| 650 | |
| 651 | #endif |
| 652 | |
| 653 | /* |
| 654 | * calibrate_tsc() calibrates the processor TSC in a very simple way, comparing |
| 655 | * it to the HPET timer of known frequency. |
| 656 | */ |
| 657 | |
| 658 | #define TICK_COUNT 100000000 |
Jack Steiner | ed5316d | 2007-01-11 01:52:44 +0100 | [diff] [blame] | 659 | #define TICK_MIN 5000 |
Jack Steiner | 2f7a2a7 | 2007-02-13 13:26:24 +0100 | [diff] [blame] | 660 | #define MAX_READ_RETRIES 5 |
Jack Steiner | ed5316d | 2007-01-11 01:52:44 +0100 | [diff] [blame] | 661 | |
| 662 | /* |
| 663 | * Some platforms take periodic SMI interrupts with 5ms duration. Make sure none |
| 664 | * occurs between the reads of the hpet & TSC. |
| 665 | */ |
| 666 | static void __init read_hpet_tsc(int *hpet, int *tsc) |
| 667 | { |
Jack Steiner | 2f7a2a7 | 2007-02-13 13:26:24 +0100 | [diff] [blame] | 668 | int tsc1, tsc2, hpet1, retries = 0; |
| 669 | static int msg; |
Jack Steiner | ed5316d | 2007-01-11 01:52:44 +0100 | [diff] [blame] | 670 | |
| 671 | do { |
| 672 | tsc1 = get_cycles_sync(); |
| 673 | hpet1 = hpet_readl(HPET_COUNTER); |
| 674 | tsc2 = get_cycles_sync(); |
Jack Steiner | 2f7a2a7 | 2007-02-13 13:26:24 +0100 | [diff] [blame] | 675 | } while (tsc2 - tsc1 > TICK_MIN && retries++ < MAX_READ_RETRIES); |
| 676 | if (retries >= MAX_READ_RETRIES && !msg++) |
| 677 | printk(KERN_WARNING |
| 678 | "hpet.c: exceeded max retries to read HPET & TSC\n"); |
Jack Steiner | ed5316d | 2007-01-11 01:52:44 +0100 | [diff] [blame] | 679 | *hpet = hpet1; |
| 680 | *tsc = tsc2; |
| 681 | } |
| 682 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 683 | |
| 684 | static unsigned int __init hpet_calibrate_tsc(void) |
| 685 | { |
| 686 | int tsc_start, hpet_start; |
| 687 | int tsc_now, hpet_now; |
| 688 | unsigned long flags; |
| 689 | |
| 690 | local_irq_save(flags); |
| 691 | local_irq_disable(); |
| 692 | |
Jack Steiner | ed5316d | 2007-01-11 01:52:44 +0100 | [diff] [blame] | 693 | read_hpet_tsc(&hpet_start, &tsc_start); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 694 | |
| 695 | do { |
| 696 | local_irq_disable(); |
Jack Steiner | ed5316d | 2007-01-11 01:52:44 +0100 | [diff] [blame] | 697 | read_hpet_tsc(&hpet_now, &tsc_now); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 698 | local_irq_restore(flags); |
| 699 | } while ((tsc_now - tsc_start) < TICK_COUNT && |
| 700 | (hpet_now - hpet_start) < TICK_COUNT); |
| 701 | |
| 702 | return (tsc_now - tsc_start) * 1000000000L |
| 703 | / ((hpet_now - hpet_start) * hpet_period / 1000); |
| 704 | } |
| 705 | |
| 706 | |
| 707 | /* |
| 708 | * pit_calibrate_tsc() uses the speaker output (channel 2) of |
| 709 | * the PIT. This is better than using the timer interrupt output, |
| 710 | * because we can read the value of the speaker with just one inb(), |
| 711 | * where we need three i/o operations for the interrupt channel. |
| 712 | * We count how many ticks the TSC does in 50 ms. |
| 713 | */ |
| 714 | |
| 715 | static unsigned int __init pit_calibrate_tsc(void) |
| 716 | { |
| 717 | unsigned long start, end; |
| 718 | unsigned long flags; |
| 719 | |
| 720 | spin_lock_irqsave(&i8253_lock, flags); |
| 721 | |
| 722 | outb((inb(0x61) & ~0x02) | 0x01, 0x61); |
| 723 | |
| 724 | outb(0xb0, 0x43); |
| 725 | outb((PIT_TICK_RATE / (1000 / 50)) & 0xff, 0x42); |
| 726 | outb((PIT_TICK_RATE / (1000 / 50)) >> 8, 0x42); |
Andi Kleen | c818a18 | 2006-01-11 22:45:24 +0100 | [diff] [blame] | 727 | start = get_cycles_sync(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 728 | while ((inb(0x61) & 0x20) == 0); |
Andi Kleen | c818a18 | 2006-01-11 22:45:24 +0100 | [diff] [blame] | 729 | end = get_cycles_sync(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 730 | |
| 731 | spin_unlock_irqrestore(&i8253_lock, flags); |
| 732 | |
| 733 | return (end - start) / 50; |
| 734 | } |
| 735 | |
| 736 | #ifdef CONFIG_HPET |
| 737 | static __init int late_hpet_init(void) |
| 738 | { |
| 739 | struct hpet_data hd; |
| 740 | unsigned int ntimer; |
| 741 | |
| 742 | if (!vxtime.hpet_address) |
Andi Kleen | 3d34ee6 | 2006-04-07 19:50:06 +0200 | [diff] [blame] | 743 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 744 | |
| 745 | memset(&hd, 0, sizeof (hd)); |
| 746 | |
| 747 | ntimer = hpet_readl(HPET_ID); |
| 748 | ntimer = (ntimer & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT; |
| 749 | ntimer++; |
| 750 | |
| 751 | /* |
| 752 | * Register with driver. |
| 753 | * Timer0 and Timer1 is used by platform. |
| 754 | */ |
| 755 | hd.hd_phys_address = vxtime.hpet_address; |
Al Viro | dd42b15 | 2006-02-01 07:30:33 -0500 | [diff] [blame] | 756 | hd.hd_address = (void __iomem *)fix_to_virt(FIX_HPET_BASE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 757 | hd.hd_nirqs = ntimer; |
| 758 | hd.hd_flags = HPET_DATA_PLATFORM; |
| 759 | hpet_reserve_timer(&hd, 0); |
| 760 | #ifdef CONFIG_HPET_EMULATE_RTC |
| 761 | hpet_reserve_timer(&hd, 1); |
| 762 | #endif |
| 763 | hd.hd_irq[0] = HPET_LEGACY_8254; |
| 764 | hd.hd_irq[1] = HPET_LEGACY_RTC; |
| 765 | if (ntimer > 2) { |
| 766 | struct hpet *hpet; |
| 767 | struct hpet_timer *timer; |
| 768 | int i; |
| 769 | |
| 770 | hpet = (struct hpet *) fix_to_virt(FIX_HPET_BASE); |
Andi Kleen | 7351c0b | 2006-03-25 16:30:34 +0100 | [diff] [blame] | 771 | timer = &hpet->hpet_timers[2]; |
| 772 | for (i = 2; i < ntimer; timer++, i++) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 773 | hd.hd_irq[i] = (timer->hpet_config & |
| 774 | Tn_INT_ROUTE_CNF_MASK) >> |
| 775 | Tn_INT_ROUTE_CNF_SHIFT; |
| 776 | |
| 777 | } |
| 778 | |
| 779 | hpet_alloc(&hd); |
| 780 | return 0; |
| 781 | } |
| 782 | fs_initcall(late_hpet_init); |
| 783 | #endif |
| 784 | |
| 785 | static int hpet_timer_stop_set_go(unsigned long tick) |
| 786 | { |
| 787 | unsigned int cfg; |
| 788 | |
| 789 | /* |
| 790 | * Stop the timers and reset the main counter. |
| 791 | */ |
| 792 | |
| 793 | cfg = hpet_readl(HPET_CFG); |
| 794 | cfg &= ~(HPET_CFG_ENABLE | HPET_CFG_LEGACY); |
| 795 | hpet_writel(cfg, HPET_CFG); |
| 796 | hpet_writel(0, HPET_COUNTER); |
| 797 | hpet_writel(0, HPET_COUNTER + 4); |
| 798 | |
| 799 | /* |
| 800 | * Set up timer 0, as periodic with first interrupt to happen at hpet_tick, |
| 801 | * and period also hpet_tick. |
| 802 | */ |
john stultz | a3a0075 | 2005-06-23 00:08:36 -0700 | [diff] [blame] | 803 | if (hpet_use_timer) { |
| 804 | hpet_writel(HPET_TN_ENABLE | HPET_TN_PERIODIC | HPET_TN_SETVAL | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 805 | HPET_TN_32BIT, HPET_T0_CFG); |
Vojtech Pavlik | b2df3dd | 2006-06-26 13:58:35 +0200 | [diff] [blame] | 806 | hpet_writel(hpet_tick, HPET_T0_CMP); /* next interrupt */ |
| 807 | hpet_writel(hpet_tick, HPET_T0_CMP); /* period */ |
john stultz | a3a0075 | 2005-06-23 00:08:36 -0700 | [diff] [blame] | 808 | cfg |= HPET_CFG_LEGACY; |
| 809 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 810 | /* |
| 811 | * Go! |
| 812 | */ |
| 813 | |
john stultz | a3a0075 | 2005-06-23 00:08:36 -0700 | [diff] [blame] | 814 | cfg |= HPET_CFG_ENABLE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 815 | hpet_writel(cfg, HPET_CFG); |
| 816 | |
| 817 | return 0; |
| 818 | } |
| 819 | |
| 820 | static int hpet_init(void) |
| 821 | { |
| 822 | unsigned int id; |
| 823 | |
| 824 | if (!vxtime.hpet_address) |
| 825 | return -1; |
| 826 | set_fixmap_nocache(FIX_HPET_BASE, vxtime.hpet_address); |
| 827 | __set_fixmap(VSYSCALL_HPET, vxtime.hpet_address, PAGE_KERNEL_VSYSCALL_NOCACHE); |
| 828 | |
| 829 | /* |
| 830 | * Read the period, compute tick and quotient. |
| 831 | */ |
| 832 | |
| 833 | id = hpet_readl(HPET_ID); |
| 834 | |
john stultz | a3a0075 | 2005-06-23 00:08:36 -0700 | [diff] [blame] | 835 | if (!(id & HPET_ID_VENDOR) || !(id & HPET_ID_NUMBER)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 836 | return -1; |
| 837 | |
| 838 | hpet_period = hpet_readl(HPET_PERIOD); |
| 839 | if (hpet_period < 100000 || hpet_period > 100000000) |
| 840 | return -1; |
| 841 | |
Vojtech Pavlik | 4221133 | 2006-06-26 13:58:32 +0200 | [diff] [blame] | 842 | hpet_tick = (FSEC_PER_TICK + hpet_period / 2) / hpet_period; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 843 | |
john stultz | a3a0075 | 2005-06-23 00:08:36 -0700 | [diff] [blame] | 844 | hpet_use_timer = (id & HPET_ID_LEGSUP); |
| 845 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 846 | return hpet_timer_stop_set_go(hpet_tick); |
| 847 | } |
| 848 | |
| 849 | static int hpet_reenable(void) |
| 850 | { |
| 851 | return hpet_timer_stop_set_go(hpet_tick); |
| 852 | } |
| 853 | |
Andi Kleen | 73dea47 | 2006-02-03 21:50:50 +0100 | [diff] [blame] | 854 | #define PIT_MODE 0x43 |
| 855 | #define PIT_CH0 0x40 |
| 856 | |
| 857 | static void __init __pit_init(int val, u8 mode) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 858 | { |
| 859 | unsigned long flags; |
| 860 | |
| 861 | spin_lock_irqsave(&i8253_lock, flags); |
Andi Kleen | 73dea47 | 2006-02-03 21:50:50 +0100 | [diff] [blame] | 862 | outb_p(mode, PIT_MODE); |
| 863 | outb_p(val & 0xff, PIT_CH0); /* LSB */ |
| 864 | outb_p(val >> 8, PIT_CH0); /* MSB */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 865 | spin_unlock_irqrestore(&i8253_lock, flags); |
| 866 | } |
| 867 | |
Andi Kleen | 73dea47 | 2006-02-03 21:50:50 +0100 | [diff] [blame] | 868 | void __init pit_init(void) |
| 869 | { |
| 870 | __pit_init(LATCH, 0x34); /* binary, mode 2, LSB/MSB, ch 0 */ |
| 871 | } |
| 872 | |
| 873 | void __init pit_stop_interrupt(void) |
| 874 | { |
| 875 | __pit_init(0, 0x30); /* mode 0 */ |
| 876 | } |
| 877 | |
| 878 | void __init stop_timer_interrupt(void) |
| 879 | { |
| 880 | char *name; |
| 881 | if (vxtime.hpet_address) { |
| 882 | name = "HPET"; |
| 883 | hpet_timer_stop_set_go(0); |
| 884 | } else { |
| 885 | name = "PIT"; |
| 886 | pit_stop_interrupt(); |
| 887 | } |
| 888 | printk(KERN_INFO "timer: %s interrupt stopped.\n", name); |
| 889 | } |
| 890 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 891 | int __init time_setup(char *str) |
| 892 | { |
| 893 | report_lost_ticks = 1; |
| 894 | return 1; |
| 895 | } |
| 896 | |
| 897 | static struct irqaction irq0 = { |
Thomas Gleixner | b1e05aa | 2006-07-01 19:29:29 -0700 | [diff] [blame] | 898 | timer_interrupt, IRQF_DISABLED, CPU_MASK_NONE, "timer", NULL, NULL |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 899 | }; |
| 900 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 901 | void __init time_init(void) |
| 902 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 903 | if (nohpet) |
| 904 | vxtime.hpet_address = 0; |
| 905 | |
| 906 | xtime.tv_sec = get_cmos_time(); |
| 907 | xtime.tv_nsec = 0; |
| 908 | |
| 909 | set_normalized_timespec(&wall_to_monotonic, |
| 910 | -xtime.tv_sec, -xtime.tv_nsec); |
| 911 | |
john stultz | a3a0075 | 2005-06-23 00:08:36 -0700 | [diff] [blame] | 912 | if (!hpet_init()) |
Vojtech Pavlik | 4221133 | 2006-06-26 13:58:32 +0200 | [diff] [blame] | 913 | vxtime_hz = (FSEC_PER_SEC + hpet_period / 2) / hpet_period; |
Andi Kleen | 68e1889 | 2005-12-12 22:17:07 -0800 | [diff] [blame] | 914 | else |
| 915 | vxtime.hpet_address = 0; |
john stultz | a3a0075 | 2005-06-23 00:08:36 -0700 | [diff] [blame] | 916 | |
| 917 | if (hpet_use_timer) { |
Jordan Hargrave | b20367a | 2006-04-07 19:50:18 +0200 | [diff] [blame] | 918 | /* set tick_nsec to use the proper rate for HPET */ |
| 919 | tick_nsec = TICK_NSEC_HPET; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 920 | cpu_khz = hpet_calibrate_tsc(); |
| 921 | timename = "HPET"; |
Andi Kleen | 312df5f | 2005-05-16 21:53:28 -0700 | [diff] [blame] | 922 | #ifdef CONFIG_X86_PM_TIMER |
john stultz | fd49547 | 2005-12-12 22:17:13 -0800 | [diff] [blame] | 923 | } else if (pmtmr_ioport && !vxtime.hpet_address) { |
Andi Kleen | 312df5f | 2005-05-16 21:53:28 -0700 | [diff] [blame] | 924 | vxtime_hz = PM_TIMER_FREQUENCY; |
| 925 | timename = "PM"; |
| 926 | pit_init(); |
| 927 | cpu_khz = pit_calibrate_tsc(); |
| 928 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 929 | } else { |
| 930 | pit_init(); |
| 931 | cpu_khz = pit_calibrate_tsc(); |
| 932 | timename = "PIT"; |
| 933 | } |
| 934 | |
Andi Kleen | e8b9177 | 2006-02-26 04:18:49 +0100 | [diff] [blame] | 935 | vxtime.mode = VXTIME_TSC; |
Vojtech Pavlik | 4221133 | 2006-06-26 13:58:32 +0200 | [diff] [blame] | 936 | vxtime.quot = (USEC_PER_SEC << US_SCALE) / vxtime_hz; |
| 937 | vxtime.tsc_quot = (USEC_PER_MSEC << US_SCALE) / cpu_khz; |
Andi Kleen | c818a18 | 2006-01-11 22:45:24 +0100 | [diff] [blame] | 938 | vxtime.last_tsc = get_cycles_sync(); |
Mathieu Desnoyers | dacb16b | 2005-10-30 14:59:25 -0800 | [diff] [blame] | 939 | set_cyc2ns_scale(cpu_khz); |
Dimitri Sivanich | cbf9b4b | 2006-09-26 10:52:34 +0200 | [diff] [blame] | 940 | setup_irq(0, &irq0); |
Vojtech Pavlik | a670fad | 2006-09-26 10:52:28 +0200 | [diff] [blame] | 941 | |
| 942 | #ifndef CONFIG_SMP |
| 943 | time_init_gtod(); |
| 944 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 945 | } |
| 946 | |
Ingo Molnar | 95492e4 | 2007-02-16 01:27:34 -0800 | [diff] [blame^] | 947 | static int tsc_unstable = 0; |
| 948 | |
| 949 | void mark_tsc_unstable(void) |
| 950 | { |
| 951 | tsc_unstable = 1; |
| 952 | } |
| 953 | EXPORT_SYMBOL_GPL(mark_tsc_unstable); |
| 954 | |
Andi Kleen | a8ab26f | 2005-04-16 15:25:19 -0700 | [diff] [blame] | 955 | /* |
Andi Kleen | 312df5f | 2005-05-16 21:53:28 -0700 | [diff] [blame] | 956 | * Make an educated guess if the TSC is trustworthy and synchronized |
| 957 | * over all CPUs. |
| 958 | */ |
Shaohua Li | 396bd50 | 2006-02-03 21:51:20 +0100 | [diff] [blame] | 959 | __cpuinit int unsynchronized_tsc(void) |
Andi Kleen | 312df5f | 2005-05-16 21:53:28 -0700 | [diff] [blame] | 960 | { |
Ingo Molnar | 95492e4 | 2007-02-16 01:27:34 -0800 | [diff] [blame^] | 961 | if (tsc_unstable) |
| 962 | return 1; |
| 963 | |
Andi Kleen | 312df5f | 2005-05-16 21:53:28 -0700 | [diff] [blame] | 964 | #ifdef CONFIG_SMP |
Vojtech Pavlik | f8bf3c6 | 2006-06-26 13:58:23 +0200 | [diff] [blame] | 965 | if (apic_is_clustered_box()) |
Andi Kleen | 312df5f | 2005-05-16 21:53:28 -0700 | [diff] [blame] | 966 | return 1; |
Andi Kleen | 312df5f | 2005-05-16 21:53:28 -0700 | [diff] [blame] | 967 | #endif |
Andi Kleen | 0e5f61b | 2006-07-29 21:42:37 +0200 | [diff] [blame] | 968 | /* Most intel systems have synchronized TSCs except for |
| 969 | multi node systems */ |
| 970 | if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) { |
| 971 | #ifdef CONFIG_ACPI |
| 972 | /* But TSC doesn't tick in C3 so don't use it there */ |
Alexey Starikovskiy | ad71860 | 2007-02-02 19:48:19 +0300 | [diff] [blame] | 973 | if (acpi_gbl_FADT.header.length > 0 && acpi_gbl_FADT.C3latency < 1000) |
Andi Kleen | 0e5f61b | 2006-07-29 21:42:37 +0200 | [diff] [blame] | 974 | return 1; |
| 975 | #endif |
| 976 | return 0; |
| 977 | } |
| 978 | |
Andi Kleen | 312df5f | 2005-05-16 21:53:28 -0700 | [diff] [blame] | 979 | /* Assume multi socket systems are not synchronized */ |
Andi Kleen | 737c5c3 | 2006-01-11 22:45:15 +0100 | [diff] [blame] | 980 | return num_present_cpus() > 1; |
Andi Kleen | 312df5f | 2005-05-16 21:53:28 -0700 | [diff] [blame] | 981 | } |
| 982 | |
| 983 | /* |
Andi Kleen | e8b9177 | 2006-02-26 04:18:49 +0100 | [diff] [blame] | 984 | * Decide what mode gettimeofday should use. |
Andi Kleen | a8ab26f | 2005-04-16 15:25:19 -0700 | [diff] [blame] | 985 | */ |
Vojtech Pavlik | a670fad | 2006-09-26 10:52:28 +0200 | [diff] [blame] | 986 | void time_init_gtod(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 987 | { |
| 988 | char *timetype; |
| 989 | |
Andi Kleen | 312df5f | 2005-05-16 21:53:28 -0700 | [diff] [blame] | 990 | if (unsynchronized_tsc()) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 991 | notsc = 1; |
Vojtech Pavlik | a670fad | 2006-09-26 10:52:28 +0200 | [diff] [blame] | 992 | |
Vojtech Pavlik | c08c820 | 2006-09-26 10:52:28 +0200 | [diff] [blame] | 993 | if (cpu_has(&boot_cpu_data, X86_FEATURE_RDTSCP)) |
| 994 | vgetcpu_mode = VGETCPU_RDTSCP; |
| 995 | else |
| 996 | vgetcpu_mode = VGETCPU_LSL; |
| 997 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 998 | if (vxtime.hpet_address && notsc) { |
john stultz | a3a0075 | 2005-06-23 00:08:36 -0700 | [diff] [blame] | 999 | timetype = hpet_use_timer ? "HPET" : "PIT/HPET"; |
Chris McDermott | 33042a9 | 2006-02-11 17:55:50 -0800 | [diff] [blame] | 1000 | if (hpet_use_timer) |
| 1001 | vxtime.last = hpet_readl(HPET_T0_CMP) - hpet_tick; |
| 1002 | else |
| 1003 | vxtime.last = hpet_readl(HPET_COUNTER); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1004 | vxtime.mode = VXTIME_HPET; |
| 1005 | do_gettimeoffset = do_gettimeoffset_hpet; |
Andi Kleen | 312df5f | 2005-05-16 21:53:28 -0700 | [diff] [blame] | 1006 | #ifdef CONFIG_X86_PM_TIMER |
| 1007 | /* Using PM for gettimeofday is quite slow, but we have no other |
| 1008 | choice because the TSC is too unreliable on some systems. */ |
| 1009 | } else if (pmtmr_ioport && !vxtime.hpet_address && notsc) { |
| 1010 | timetype = "PM"; |
| 1011 | do_gettimeoffset = do_gettimeoffset_pm; |
| 1012 | vxtime.mode = VXTIME_PMTMR; |
| 1013 | sysctl_vsyscall = 0; |
| 1014 | printk(KERN_INFO "Disabling vsyscall due to use of PM timer\n"); |
| 1015 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1016 | } else { |
john stultz | a3a0075 | 2005-06-23 00:08:36 -0700 | [diff] [blame] | 1017 | timetype = hpet_use_timer ? "HPET/TSC" : "PIT/TSC"; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1018 | vxtime.mode = VXTIME_TSC; |
| 1019 | } |
Vojtech Pavlik | a670fad | 2006-09-26 10:52:28 +0200 | [diff] [blame] | 1020 | |
| 1021 | printk(KERN_INFO "time.c: Using %ld.%06ld MHz WALL %s GTOD %s timer.\n", |
| 1022 | vxtime_hz / 1000000, vxtime_hz % 1000000, timename, timetype); |
| 1023 | printk(KERN_INFO "time.c: Detected %d.%03d MHz processor.\n", |
| 1024 | cpu_khz / 1000, cpu_khz % 1000); |
| 1025 | vxtime.quot = (USEC_PER_SEC << US_SCALE) / vxtime_hz; |
| 1026 | vxtime.tsc_quot = (USEC_PER_MSEC << US_SCALE) / cpu_khz; |
| 1027 | vxtime.last_tsc = get_cycles_sync(); |
| 1028 | |
| 1029 | set_cyc2ns_scale(cpu_khz); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1030 | } |
| 1031 | |
| 1032 | __setup("report_lost_ticks", time_setup); |
| 1033 | |
| 1034 | static long clock_cmos_diff; |
| 1035 | static unsigned long sleep_start; |
| 1036 | |
Andi Kleen | 0b91317 | 2006-01-11 22:45:33 +0100 | [diff] [blame] | 1037 | /* |
| 1038 | * sysfs support for the timer. |
| 1039 | */ |
| 1040 | |
Pavel Machek | 0b9c33a | 2005-04-16 15:25:31 -0700 | [diff] [blame] | 1041 | static int timer_suspend(struct sys_device *dev, pm_message_t state) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1042 | { |
| 1043 | /* |
| 1044 | * Estimate time zone so that set_time can update the clock |
| 1045 | */ |
| 1046 | long cmos_time = get_cmos_time(); |
| 1047 | |
| 1048 | clock_cmos_diff = -cmos_time; |
| 1049 | clock_cmos_diff += get_seconds(); |
| 1050 | sleep_start = cmos_time; |
| 1051 | return 0; |
| 1052 | } |
| 1053 | |
| 1054 | static int timer_resume(struct sys_device *dev) |
| 1055 | { |
| 1056 | unsigned long flags; |
| 1057 | unsigned long sec; |
| 1058 | unsigned long ctime = get_cmos_time(); |
Rafael J. Wysocki | 34464a5 | 2006-09-26 10:52:37 +0200 | [diff] [blame] | 1059 | long sleep_length = (ctime - sleep_start) * HZ; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1060 | |
Rafael J. Wysocki | 34464a5 | 2006-09-26 10:52:37 +0200 | [diff] [blame] | 1061 | if (sleep_length < 0) { |
| 1062 | printk(KERN_WARNING "Time skew detected in timer resume!\n"); |
| 1063 | /* The time after the resume must not be earlier than the time |
| 1064 | * before the suspend or some nasty things will happen |
| 1065 | */ |
| 1066 | sleep_length = 0; |
| 1067 | ctime = sleep_start; |
| 1068 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1069 | if (vxtime.hpet_address) |
| 1070 | hpet_reenable(); |
| 1071 | else |
| 1072 | i8254_timer_resume(); |
| 1073 | |
| 1074 | sec = ctime + clock_cmos_diff; |
| 1075 | write_seqlock_irqsave(&xtime_lock,flags); |
| 1076 | xtime.tv_sec = sec; |
| 1077 | xtime.tv_nsec = 0; |
Shaohua Li | 0dd2ea9 | 2006-02-03 21:50:56 +0100 | [diff] [blame] | 1078 | if (vxtime.mode == VXTIME_HPET) { |
| 1079 | if (hpet_use_timer) |
| 1080 | vxtime.last = hpet_readl(HPET_T0_CMP) - hpet_tick; |
| 1081 | else |
| 1082 | vxtime.last = hpet_readl(HPET_COUNTER); |
| 1083 | #ifdef CONFIG_X86_PM_TIMER |
| 1084 | } else if (vxtime.mode == VXTIME_PMTMR) { |
| 1085 | pmtimer_resume(); |
| 1086 | #endif |
| 1087 | } else |
| 1088 | vxtime.last_tsc = get_cycles_sync(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1089 | write_sequnlock_irqrestore(&xtime_lock,flags); |
| 1090 | jiffies += sleep_length; |
Shaohua Li | 0dd2ea9 | 2006-02-03 21:50:56 +0100 | [diff] [blame] | 1091 | monotonic_base += sleep_length * (NSEC_PER_SEC/HZ); |
Ingo Molnar | 8446f1d | 2005-09-06 15:16:27 -0700 | [diff] [blame] | 1092 | touch_softlockup_watchdog(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1093 | return 0; |
| 1094 | } |
| 1095 | |
| 1096 | static struct sysdev_class timer_sysclass = { |
| 1097 | .resume = timer_resume, |
| 1098 | .suspend = timer_suspend, |
| 1099 | set_kset_name("timer"), |
| 1100 | }; |
| 1101 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1102 | /* XXX this driverfs stuff should probably go elsewhere later -john */ |
| 1103 | static struct sys_device device_timer = { |
| 1104 | .id = 0, |
| 1105 | .cls = &timer_sysclass, |
| 1106 | }; |
| 1107 | |
| 1108 | static int time_init_device(void) |
| 1109 | { |
| 1110 | int error = sysdev_class_register(&timer_sysclass); |
| 1111 | if (!error) |
| 1112 | error = sysdev_register(&device_timer); |
| 1113 | return error; |
| 1114 | } |
| 1115 | |
| 1116 | device_initcall(time_init_device); |
| 1117 | |
| 1118 | #ifdef CONFIG_HPET_EMULATE_RTC |
| 1119 | /* HPET in LegacyReplacement Mode eats up RTC interrupt line. When, HPET |
| 1120 | * is enabled, we support RTC interrupt functionality in software. |
| 1121 | * RTC has 3 kinds of interrupts: |
| 1122 | * 1) Update Interrupt - generate an interrupt, every sec, when RTC clock |
| 1123 | * is updated |
| 1124 | * 2) Alarm Interrupt - generate an interrupt at a specific time of day |
| 1125 | * 3) Periodic Interrupt - generate periodic interrupt, with frequencies |
| 1126 | * 2Hz-8192Hz (2Hz-64Hz for non-root user) (all freqs in powers of 2) |
| 1127 | * (1) and (2) above are implemented using polling at a frequency of |
| 1128 | * 64 Hz. The exact frequency is a tradeoff between accuracy and interrupt |
| 1129 | * overhead. (DEFAULT_RTC_INT_FREQ) |
| 1130 | * For (3), we use interrupts at 64Hz or user specified periodic |
| 1131 | * frequency, whichever is higher. |
| 1132 | */ |
| 1133 | #include <linux/rtc.h> |
| 1134 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1135 | #define DEFAULT_RTC_INT_FREQ 64 |
| 1136 | #define RTC_NUM_INTS 1 |
| 1137 | |
| 1138 | static unsigned long UIE_on; |
| 1139 | static unsigned long prev_update_sec; |
| 1140 | |
| 1141 | static unsigned long AIE_on; |
| 1142 | static struct rtc_time alarm_time; |
| 1143 | |
| 1144 | static unsigned long PIE_on; |
| 1145 | static unsigned long PIE_freq = DEFAULT_RTC_INT_FREQ; |
| 1146 | static unsigned long PIE_count; |
| 1147 | |
| 1148 | static unsigned long hpet_rtc_int_freq; /* RTC interrupt frequency */ |
Clemens Ladisch | 7811fb8 | 2005-10-30 15:03:36 -0800 | [diff] [blame] | 1149 | static unsigned int hpet_t1_cmp; /* cached comparator register */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1150 | |
| 1151 | int is_hpet_enabled(void) |
| 1152 | { |
| 1153 | return vxtime.hpet_address != 0; |
| 1154 | } |
| 1155 | |
| 1156 | /* |
| 1157 | * Timer 1 for RTC, we do not use periodic interrupt feature, |
| 1158 | * even if HPET supports periodic interrupts on Timer 1. |
| 1159 | * The reason being, to set up a periodic interrupt in HPET, we need to |
| 1160 | * stop the main counter. And if we do that everytime someone diables/enables |
| 1161 | * RTC, we will have adverse effect on main kernel timer running on Timer 0. |
| 1162 | * So, for the time being, simulate the periodic interrupt in software. |
| 1163 | * |
| 1164 | * hpet_rtc_timer_init() is called for the first time and during subsequent |
| 1165 | * interuppts reinit happens through hpet_rtc_timer_reinit(). |
| 1166 | */ |
| 1167 | int hpet_rtc_timer_init(void) |
| 1168 | { |
| 1169 | unsigned int cfg, cnt; |
| 1170 | unsigned long flags; |
| 1171 | |
| 1172 | if (!is_hpet_enabled()) |
| 1173 | return 0; |
| 1174 | /* |
| 1175 | * Set the counter 1 and enable the interrupts. |
| 1176 | */ |
| 1177 | if (PIE_on && (PIE_freq > DEFAULT_RTC_INT_FREQ)) |
| 1178 | hpet_rtc_int_freq = PIE_freq; |
| 1179 | else |
| 1180 | hpet_rtc_int_freq = DEFAULT_RTC_INT_FREQ; |
| 1181 | |
| 1182 | local_irq_save(flags); |
Clemens Ladisch | 1447c27 | 2006-09-25 23:32:17 -0700 | [diff] [blame] | 1183 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1184 | cnt = hpet_readl(HPET_COUNTER); |
| 1185 | cnt += ((hpet_tick*HZ)/hpet_rtc_int_freq); |
| 1186 | hpet_writel(cnt, HPET_T1_CMP); |
Clemens Ladisch | 7811fb8 | 2005-10-30 15:03:36 -0800 | [diff] [blame] | 1187 | hpet_t1_cmp = cnt; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1188 | |
| 1189 | cfg = hpet_readl(HPET_T1_CFG); |
Clemens Ladisch | 5f81994 | 2005-10-30 15:03:36 -0800 | [diff] [blame] | 1190 | cfg &= ~HPET_TN_PERIODIC; |
| 1191 | cfg |= HPET_TN_ENABLE | HPET_TN_32BIT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1192 | hpet_writel(cfg, HPET_T1_CFG); |
| 1193 | |
Clemens Ladisch | 1447c27 | 2006-09-25 23:32:17 -0700 | [diff] [blame] | 1194 | local_irq_restore(flags); |
| 1195 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1196 | return 1; |
| 1197 | } |
| 1198 | |
| 1199 | static void hpet_rtc_timer_reinit(void) |
| 1200 | { |
Clemens Ladisch | 1447c27 | 2006-09-25 23:32:17 -0700 | [diff] [blame] | 1201 | unsigned int cfg, cnt, ticks_per_int, lost_ints; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1202 | |
Clemens Ladisch | f00c96f | 2005-10-30 15:03:35 -0800 | [diff] [blame] | 1203 | if (unlikely(!(PIE_on | AIE_on | UIE_on))) { |
| 1204 | cfg = hpet_readl(HPET_T1_CFG); |
| 1205 | cfg &= ~HPET_TN_ENABLE; |
| 1206 | hpet_writel(cfg, HPET_T1_CFG); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1207 | return; |
Clemens Ladisch | f00c96f | 2005-10-30 15:03:35 -0800 | [diff] [blame] | 1208 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1209 | |
| 1210 | if (PIE_on && (PIE_freq > DEFAULT_RTC_INT_FREQ)) |
| 1211 | hpet_rtc_int_freq = PIE_freq; |
| 1212 | else |
| 1213 | hpet_rtc_int_freq = DEFAULT_RTC_INT_FREQ; |
| 1214 | |
| 1215 | /* It is more accurate to use the comparator value than current count.*/ |
Clemens Ladisch | 1447c27 | 2006-09-25 23:32:17 -0700 | [diff] [blame] | 1216 | ticks_per_int = hpet_tick * HZ / hpet_rtc_int_freq; |
| 1217 | hpet_t1_cmp += ticks_per_int; |
| 1218 | hpet_writel(hpet_t1_cmp, HPET_T1_CMP); |
| 1219 | |
| 1220 | /* |
| 1221 | * If the interrupt handler was delayed too long, the write above tries |
| 1222 | * to schedule the next interrupt in the past and the hardware would |
| 1223 | * not interrupt until the counter had wrapped around. |
| 1224 | * So we have to check that the comparator wasn't set to a past time. |
| 1225 | */ |
| 1226 | cnt = hpet_readl(HPET_COUNTER); |
| 1227 | if (unlikely((int)(cnt - hpet_t1_cmp) > 0)) { |
| 1228 | lost_ints = (cnt - hpet_t1_cmp) / ticks_per_int + 1; |
| 1229 | /* Make sure that, even with the time needed to execute |
| 1230 | * this code, the next scheduled interrupt has been moved |
| 1231 | * back to the future: */ |
| 1232 | lost_ints++; |
| 1233 | |
| 1234 | hpet_t1_cmp += lost_ints * ticks_per_int; |
| 1235 | hpet_writel(hpet_t1_cmp, HPET_T1_CMP); |
| 1236 | |
| 1237 | if (PIE_on) |
| 1238 | PIE_count += lost_ints; |
| 1239 | |
Roland Dreier | 3e94fb8 | 2007-02-13 13:26:25 +0100 | [diff] [blame] | 1240 | if (printk_ratelimit()) |
| 1241 | printk(KERN_WARNING "rtc: lost some interrupts at %ldHz.\n", |
| 1242 | hpet_rtc_int_freq); |
Clemens Ladisch | 1447c27 | 2006-09-25 23:32:17 -0700 | [diff] [blame] | 1243 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1244 | } |
| 1245 | |
| 1246 | /* |
| 1247 | * The functions below are called from rtc driver. |
| 1248 | * Return 0 if HPET is not being used. |
| 1249 | * Otherwise do the necessary changes and return 1. |
| 1250 | */ |
| 1251 | int hpet_mask_rtc_irq_bit(unsigned long bit_mask) |
| 1252 | { |
| 1253 | if (!is_hpet_enabled()) |
| 1254 | return 0; |
| 1255 | |
| 1256 | if (bit_mask & RTC_UIE) |
| 1257 | UIE_on = 0; |
| 1258 | if (bit_mask & RTC_PIE) |
| 1259 | PIE_on = 0; |
| 1260 | if (bit_mask & RTC_AIE) |
| 1261 | AIE_on = 0; |
| 1262 | |
| 1263 | return 1; |
| 1264 | } |
| 1265 | |
| 1266 | int hpet_set_rtc_irq_bit(unsigned long bit_mask) |
| 1267 | { |
| 1268 | int timer_init_reqd = 0; |
| 1269 | |
| 1270 | if (!is_hpet_enabled()) |
| 1271 | return 0; |
| 1272 | |
| 1273 | if (!(PIE_on | AIE_on | UIE_on)) |
| 1274 | timer_init_reqd = 1; |
| 1275 | |
| 1276 | if (bit_mask & RTC_UIE) { |
| 1277 | UIE_on = 1; |
| 1278 | } |
| 1279 | if (bit_mask & RTC_PIE) { |
| 1280 | PIE_on = 1; |
| 1281 | PIE_count = 0; |
| 1282 | } |
| 1283 | if (bit_mask & RTC_AIE) { |
| 1284 | AIE_on = 1; |
| 1285 | } |
| 1286 | |
| 1287 | if (timer_init_reqd) |
| 1288 | hpet_rtc_timer_init(); |
| 1289 | |
| 1290 | return 1; |
| 1291 | } |
| 1292 | |
| 1293 | int hpet_set_alarm_time(unsigned char hrs, unsigned char min, unsigned char sec) |
| 1294 | { |
| 1295 | if (!is_hpet_enabled()) |
| 1296 | return 0; |
| 1297 | |
| 1298 | alarm_time.tm_hour = hrs; |
| 1299 | alarm_time.tm_min = min; |
| 1300 | alarm_time.tm_sec = sec; |
| 1301 | |
| 1302 | return 1; |
| 1303 | } |
| 1304 | |
| 1305 | int hpet_set_periodic_freq(unsigned long freq) |
| 1306 | { |
| 1307 | if (!is_hpet_enabled()) |
| 1308 | return 0; |
| 1309 | |
| 1310 | PIE_freq = freq; |
| 1311 | PIE_count = 0; |
| 1312 | |
| 1313 | return 1; |
| 1314 | } |
| 1315 | |
| 1316 | int hpet_rtc_dropped_irq(void) |
| 1317 | { |
| 1318 | if (!is_hpet_enabled()) |
| 1319 | return 0; |
| 1320 | |
| 1321 | return 1; |
| 1322 | } |
| 1323 | |
| 1324 | irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id, struct pt_regs *regs) |
| 1325 | { |
| 1326 | struct rtc_time curr_time; |
| 1327 | unsigned long rtc_int_flag = 0; |
| 1328 | int call_rtc_interrupt = 0; |
| 1329 | |
| 1330 | hpet_rtc_timer_reinit(); |
| 1331 | |
| 1332 | if (UIE_on | AIE_on) { |
| 1333 | rtc_get_rtc_time(&curr_time); |
| 1334 | } |
| 1335 | if (UIE_on) { |
| 1336 | if (curr_time.tm_sec != prev_update_sec) { |
| 1337 | /* Set update int info, call real rtc int routine */ |
| 1338 | call_rtc_interrupt = 1; |
| 1339 | rtc_int_flag = RTC_UF; |
| 1340 | prev_update_sec = curr_time.tm_sec; |
| 1341 | } |
| 1342 | } |
| 1343 | if (PIE_on) { |
| 1344 | PIE_count++; |
| 1345 | if (PIE_count >= hpet_rtc_int_freq/PIE_freq) { |
| 1346 | /* Set periodic int info, call real rtc int routine */ |
| 1347 | call_rtc_interrupt = 1; |
| 1348 | rtc_int_flag |= RTC_PF; |
| 1349 | PIE_count = 0; |
| 1350 | } |
| 1351 | } |
| 1352 | if (AIE_on) { |
| 1353 | if ((curr_time.tm_sec == alarm_time.tm_sec) && |
| 1354 | (curr_time.tm_min == alarm_time.tm_min) && |
| 1355 | (curr_time.tm_hour == alarm_time.tm_hour)) { |
| 1356 | /* Set alarm int info, call real rtc int routine */ |
| 1357 | call_rtc_interrupt = 1; |
| 1358 | rtc_int_flag |= RTC_AF; |
| 1359 | } |
| 1360 | } |
| 1361 | if (call_rtc_interrupt) { |
| 1362 | rtc_int_flag |= (RTC_IRQF | (RTC_NUM_INTS << 8)); |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 1363 | rtc_interrupt(rtc_int_flag, dev_id); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1364 | } |
| 1365 | return IRQ_HANDLED; |
| 1366 | } |
| 1367 | #endif |
| 1368 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1369 | static int __init nohpet_setup(char *s) |
| 1370 | { |
| 1371 | nohpet = 1; |
OGAWA Hirofumi | 9b41046 | 2006-03-31 02:30:33 -0800 | [diff] [blame] | 1372 | return 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1373 | } |
| 1374 | |
| 1375 | __setup("nohpet", nohpet_setup); |
| 1376 | |
Andi Kleen | 7fd6784 | 2006-02-16 23:42:07 +0100 | [diff] [blame] | 1377 | int __init notsc_setup(char *s) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1378 | { |
| 1379 | notsc = 1; |
OGAWA Hirofumi | 9b41046 | 2006-03-31 02:30:33 -0800 | [diff] [blame] | 1380 | return 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1381 | } |
| 1382 | |
| 1383 | __setup("notsc", notsc_setup); |