diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/parisc/kernel/time.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'arch/parisc/kernel/time.c')
-rw-r--r-- | arch/parisc/kernel/time.c | 243 |
1 files changed, 243 insertions, 0 deletions
diff --git a/arch/parisc/kernel/time.c b/arch/parisc/kernel/time.c new file mode 100644 index 000000000000..6cf7407344ba --- /dev/null +++ b/arch/parisc/kernel/time.c | |||
@@ -0,0 +1,243 @@ | |||
1 | /* | ||
2 | * linux/arch/parisc/kernel/time.c | ||
3 | * | ||
4 | * Copyright (C) 1991, 1992, 1995 Linus Torvalds | ||
5 | * Modifications for ARM (C) 1994, 1995, 1996,1997 Russell King | ||
6 | * Copyright (C) 1999 SuSE GmbH, (Philipp Rumpf, prumpf@tux.org) | ||
7 | * | ||
8 | * 1994-07-02 Alan Modra | ||
9 | * fixed set_rtc_mmss, fixed time.year for >= 2000, new mktime | ||
10 | * 1998-12-20 Updated NTP code according to technical memorandum Jan '96 | ||
11 | * "A Kernel Model for Precision Timekeeping" by Dave Mills | ||
12 | */ | ||
13 | #include <linux/config.h> | ||
14 | #include <linux/errno.h> | ||
15 | #include <linux/module.h> | ||
16 | #include <linux/sched.h> | ||
17 | #include <linux/kernel.h> | ||
18 | #include <linux/param.h> | ||
19 | #include <linux/string.h> | ||
20 | #include <linux/mm.h> | ||
21 | #include <linux/interrupt.h> | ||
22 | #include <linux/time.h> | ||
23 | #include <linux/init.h> | ||
24 | #include <linux/smp.h> | ||
25 | #include <linux/profile.h> | ||
26 | |||
27 | #include <asm/uaccess.h> | ||
28 | #include <asm/io.h> | ||
29 | #include <asm/irq.h> | ||
30 | #include <asm/param.h> | ||
31 | #include <asm/pdc.h> | ||
32 | #include <asm/led.h> | ||
33 | |||
34 | #include <linux/timex.h> | ||
35 | |||
36 | u64 jiffies_64 = INITIAL_JIFFIES; | ||
37 | |||
38 | EXPORT_SYMBOL(jiffies_64); | ||
39 | |||
40 | /* xtime and wall_jiffies keep wall-clock time */ | ||
41 | extern unsigned long wall_jiffies; | ||
42 | |||
43 | static long clocktick; /* timer cycles per tick */ | ||
44 | static long halftick; | ||
45 | |||
46 | #ifdef CONFIG_SMP | ||
47 | extern void smp_do_timer(struct pt_regs *regs); | ||
48 | #endif | ||
49 | |||
50 | irqreturn_t timer_interrupt(int irq, void *dev_id, struct pt_regs *regs) | ||
51 | { | ||
52 | long now; | ||
53 | long next_tick; | ||
54 | int nticks; | ||
55 | int cpu = smp_processor_id(); | ||
56 | |||
57 | profile_tick(CPU_PROFILING, regs); | ||
58 | |||
59 | now = mfctl(16); | ||
60 | /* initialize next_tick to time at last clocktick */ | ||
61 | next_tick = cpu_data[cpu].it_value; | ||
62 | |||
63 | /* since time passes between the interrupt and the mfctl() | ||
64 | * above, it is never true that last_tick + clocktick == now. If we | ||
65 | * never miss a clocktick, we could set next_tick = last_tick + clocktick | ||
66 | * but maybe we'll miss ticks, hence the loop. | ||
67 | * | ||
68 | * Variables are *signed*. | ||
69 | */ | ||
70 | |||
71 | nticks = 0; | ||
72 | while((next_tick - now) < halftick) { | ||
73 | next_tick += clocktick; | ||
74 | nticks++; | ||
75 | } | ||
76 | mtctl(next_tick, 16); | ||
77 | cpu_data[cpu].it_value = next_tick; | ||
78 | |||
79 | while (nticks--) { | ||
80 | #ifdef CONFIG_SMP | ||
81 | smp_do_timer(regs); | ||
82 | #else | ||
83 | update_process_times(user_mode(regs)); | ||
84 | #endif | ||
85 | if (cpu == 0) { | ||
86 | write_seqlock(&xtime_lock); | ||
87 | do_timer(regs); | ||
88 | write_sequnlock(&xtime_lock); | ||
89 | } | ||
90 | } | ||
91 | |||
92 | #ifdef CONFIG_CHASSIS_LCD_LED | ||
93 | /* Only schedule the led tasklet on cpu 0, and only if it | ||
94 | * is enabled. | ||
95 | */ | ||
96 | if (cpu == 0 && !atomic_read(&led_tasklet.count)) | ||
97 | tasklet_schedule(&led_tasklet); | ||
98 | #endif | ||
99 | |||
100 | /* check soft power switch status */ | ||
101 | if (cpu == 0 && !atomic_read(&power_tasklet.count)) | ||
102 | tasklet_schedule(&power_tasklet); | ||
103 | |||
104 | return IRQ_HANDLED; | ||
105 | } | ||
106 | |||
107 | /*** converted from ia64 ***/ | ||
108 | /* | ||
109 | * Return the number of micro-seconds that elapsed since the last | ||
110 | * update to wall time (aka xtime aka wall_jiffies). The xtime_lock | ||
111 | * must be at least read-locked when calling this routine. | ||
112 | */ | ||
113 | static inline unsigned long | ||
114 | gettimeoffset (void) | ||
115 | { | ||
116 | #ifndef CONFIG_SMP | ||
117 | /* | ||
118 | * FIXME: This won't work on smp because jiffies are updated by cpu 0. | ||
119 | * Once parisc-linux learns the cr16 difference between processors, | ||
120 | * this could be made to work. | ||
121 | */ | ||
122 | long last_tick; | ||
123 | long elapsed_cycles; | ||
124 | |||
125 | /* it_value is the intended time of the next tick */ | ||
126 | last_tick = cpu_data[smp_processor_id()].it_value; | ||
127 | |||
128 | /* Subtract one tick and account for possible difference between | ||
129 | * when we expected the tick and when it actually arrived. | ||
130 | * (aka wall vs real) | ||
131 | */ | ||
132 | last_tick -= clocktick * (jiffies - wall_jiffies + 1); | ||
133 | elapsed_cycles = mfctl(16) - last_tick; | ||
134 | |||
135 | /* the precision of this math could be improved */ | ||
136 | return elapsed_cycles / (PAGE0->mem_10msec / 10000); | ||
137 | #else | ||
138 | return 0; | ||
139 | #endif | ||
140 | } | ||
141 | |||
142 | void | ||
143 | do_gettimeofday (struct timeval *tv) | ||
144 | { | ||
145 | unsigned long flags, seq, usec, sec; | ||
146 | |||
147 | do { | ||
148 | seq = read_seqbegin_irqsave(&xtime_lock, flags); | ||
149 | usec = gettimeoffset(); | ||
150 | sec = xtime.tv_sec; | ||
151 | usec += (xtime.tv_nsec / 1000); | ||
152 | } while (read_seqretry_irqrestore(&xtime_lock, seq, flags)); | ||
153 | |||
154 | while (usec >= 1000000) { | ||
155 | usec -= 1000000; | ||
156 | ++sec; | ||
157 | } | ||
158 | |||
159 | tv->tv_sec = sec; | ||
160 | tv->tv_usec = usec; | ||
161 | } | ||
162 | |||
163 | EXPORT_SYMBOL(do_gettimeofday); | ||
164 | |||
165 | int | ||
166 | do_settimeofday (struct timespec *tv) | ||
167 | { | ||
168 | time_t wtm_sec, sec = tv->tv_sec; | ||
169 | long wtm_nsec, nsec = tv->tv_nsec; | ||
170 | |||
171 | if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC) | ||
172 | return -EINVAL; | ||
173 | |||
174 | write_seqlock_irq(&xtime_lock); | ||
175 | { | ||
176 | /* | ||
177 | * This is revolting. We need to set "xtime" | ||
178 | * correctly. However, the value in this location is | ||
179 | * the value at the most recent update of wall time. | ||
180 | * Discover what correction gettimeofday would have | ||
181 | * done, and then undo it! | ||
182 | */ | ||
183 | nsec -= gettimeoffset() * 1000; | ||
184 | |||
185 | wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec); | ||
186 | wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec); | ||
187 | |||
188 | set_normalized_timespec(&xtime, sec, nsec); | ||
189 | set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec); | ||
190 | |||
191 | time_adjust = 0; /* stop active adjtime() */ | ||
192 | time_status |= STA_UNSYNC; | ||
193 | time_maxerror = NTP_PHASE_LIMIT; | ||
194 | time_esterror = NTP_PHASE_LIMIT; | ||
195 | } | ||
196 | write_sequnlock_irq(&xtime_lock); | ||
197 | clock_was_set(); | ||
198 | return 0; | ||
199 | } | ||
200 | EXPORT_SYMBOL(do_settimeofday); | ||
201 | |||
202 | /* | ||
203 | * XXX: We can do better than this. | ||
204 | * Returns nanoseconds | ||
205 | */ | ||
206 | |||
207 | unsigned long long sched_clock(void) | ||
208 | { | ||
209 | return (unsigned long long)jiffies * (1000000000 / HZ); | ||
210 | } | ||
211 | |||
212 | |||
213 | void __init time_init(void) | ||
214 | { | ||
215 | unsigned long next_tick; | ||
216 | static struct pdc_tod tod_data; | ||
217 | |||
218 | clocktick = (100 * PAGE0->mem_10msec) / HZ; | ||
219 | halftick = clocktick / 2; | ||
220 | |||
221 | /* Setup clock interrupt timing */ | ||
222 | |||
223 | next_tick = mfctl(16); | ||
224 | next_tick += clocktick; | ||
225 | cpu_data[smp_processor_id()].it_value = next_tick; | ||
226 | |||
227 | /* kick off Itimer (CR16) */ | ||
228 | mtctl(next_tick, 16); | ||
229 | |||
230 | if(pdc_tod_read(&tod_data) == 0) { | ||
231 | write_seqlock_irq(&xtime_lock); | ||
232 | xtime.tv_sec = tod_data.tod_sec; | ||
233 | xtime.tv_nsec = tod_data.tod_usec * 1000; | ||
234 | set_normalized_timespec(&wall_to_monotonic, | ||
235 | -xtime.tv_sec, -xtime.tv_nsec); | ||
236 | write_sequnlock_irq(&xtime_lock); | ||
237 | } else { | ||
238 | printk(KERN_ERR "Error reading tod clock\n"); | ||
239 | xtime.tv_sec = 0; | ||
240 | xtime.tv_nsec = 0; | ||
241 | } | ||
242 | } | ||
243 | |||