1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
|
/*
* Copyright (C) 2000 Jeff Dike (jdike@karaya.com)
* Licensed under the GPL
*/
#include "linux/kernel.h"
#include "linux/module.h"
#include "linux/unistd.h"
#include "linux/stddef.h"
#include "linux/spinlock.h"
#include "linux/time.h"
#include "linux/sched.h"
#include "linux/interrupt.h"
#include "linux/init.h"
#include "linux/delay.h"
#include "linux/hrtimer.h"
#include "asm/irq.h"
#include "asm/param.h"
#include "asm/current.h"
#include "kern_util.h"
#include "mode.h"
#include "os.h"
int hz(void)
{
return(HZ);
}
/*
* Scheduler clock - returns current time in nanosec units.
*/
unsigned long long sched_clock(void)
{
return (unsigned long long)jiffies_64 * (1000000000 / HZ);
}
#ifdef CONFIG_UML_REAL_TIME_CLOCK
static unsigned long long prev_nsecs[NR_CPUS];
static long long delta[NR_CPUS]; /* Deviation per interval */
#endif
void timer_irq(union uml_pt_regs *regs)
{
unsigned long long ticks = 0;
#ifdef CONFIG_UML_REAL_TIME_CLOCK
int c = cpu();
if(prev_nsecs[c]){
/* We've had 1 tick */
unsigned long long nsecs = os_nsecs();
delta[c] += nsecs - prev_nsecs[c];
prev_nsecs[c] = nsecs;
/* Protect against the host clock being set backwards */
if(delta[c] < 0)
delta[c] = 0;
ticks += (delta[c] * HZ) / BILLION;
delta[c] -= (ticks * BILLION) / HZ;
}
else prev_nsecs[c] = os_nsecs();
#else
ticks = 1;
#endif
while(ticks > 0){
do_IRQ(TIMER_IRQ, regs);
ticks--;
}
}
/* Protects local_offset */
static DEFINE_SPINLOCK(timer_spinlock);
static unsigned long long local_offset = 0;
static inline unsigned long long get_time(void)
{
unsigned long long nsecs;
unsigned long flags;
spin_lock_irqsave(&timer_spinlock, flags);
nsecs = os_nsecs();
nsecs += local_offset;
spin_unlock_irqrestore(&timer_spinlock, flags);
return nsecs;
}
irqreturn_t um_timer(int irq, void *dev)
{
unsigned long long nsecs;
unsigned long flags;
write_seqlock_irqsave(&xtime_lock, flags);
do_timer(1);
#ifdef CONFIG_UML_REAL_TIME_CLOCK
nsecs = get_time();
#else
nsecs = (unsigned long long) xtime.tv_sec * BILLION + xtime.tv_nsec +
BILLION / HZ;
#endif
xtime.tv_sec = nsecs / NSEC_PER_SEC;
xtime.tv_nsec = nsecs - xtime.tv_sec * NSEC_PER_SEC;
write_sequnlock_irqrestore(&xtime_lock, flags);
return IRQ_HANDLED;
}
static void register_timer(void)
{
int err;
err = request_irq(TIMER_IRQ, um_timer, IRQF_DISABLED, "timer", NULL);
if(err != 0)
printk(KERN_ERR "register_timer : request_irq failed - "
"errno = %d\n", -err);
err = set_interval(1);
if(err != 0)
printk(KERN_ERR "register_timer : set_interval failed - "
"errno = %d\n", -err);
}
extern void (*late_time_init)(void);
void time_init(void)
{
long long nsecs;
nsecs = os_nsecs();
set_normalized_timespec(&wall_to_monotonic, -nsecs / BILLION,
-nsecs % BILLION);
set_normalized_timespec(&xtime, nsecs / BILLION, nsecs % BILLION);
late_time_init = register_timer;
}
void do_gettimeofday(struct timeval *tv)
{
#ifdef CONFIG_UML_REAL_TIME_CLOCK
unsigned long long nsecs = get_time();
#else
unsigned long long nsecs = (unsigned long long) xtime.tv_sec * BILLION +
xtime.tv_nsec;
#endif
tv->tv_sec = nsecs / NSEC_PER_SEC;
/* Careful about calculations here - this was originally done as
* (nsecs - tv->tv_sec * NSEC_PER_SEC) / NSEC_PER_USEC
* which gave bogus (> 1000000) values. Dunno why, suspect gcc
* (4.0.0) miscompiled it, or there's a subtle 64/32-bit conversion
* problem that I missed.
*/
nsecs -= tv->tv_sec * NSEC_PER_SEC;
tv->tv_usec = (unsigned long) nsecs / NSEC_PER_USEC;
}
static inline void set_time(unsigned long long nsecs)
{
unsigned long long now;
unsigned long flags;
spin_lock_irqsave(&timer_spinlock, flags);
now = os_nsecs();
local_offset = nsecs - now;
spin_unlock_irqrestore(&timer_spinlock, flags);
clock_was_set();
}
int do_settimeofday(struct timespec *tv)
{
set_time((unsigned long long) tv->tv_sec * NSEC_PER_SEC + tv->tv_nsec);
return 0;
}
void timer_handler(int sig, union uml_pt_regs *regs)
{
local_irq_disable();
irq_enter();
update_process_times(CHOOSE_MODE(
(UPT_SC(regs) && user_context(UPT_SP(regs))),
(regs)->skas.is_user));
irq_exit();
local_irq_enable();
if(current_thread->cpu == 0)
timer_irq(regs);
}
|
