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
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
|
/* MN10300 Low level time management
*
* Copyright (C) 2007-2008 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
* - Derived from arch/i386/kernel/time.c
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public Licence
* as published by the Free Software Foundation; either version
* 2 of the Licence, or (at your option) any later version.
*/
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/interrupt.h>
#include <linux/time.h>
#include <linux/init.h>
#include <linux/smp.h>
#include <linux/profile.h>
#include <linux/cnt32_to_63.h>
#include <linux/clocksource.h>
#include <linux/clockchips.h>
#include <asm/irq.h>
#include <asm/div64.h>
#include <asm/processor.h>
#include <asm/intctl-regs.h>
#include <asm/rtc.h>
#include "internal.h"
static unsigned long mn10300_last_tsc; /* time-stamp counter at last time
* interrupt occurred */
static unsigned long sched_clock_multiplier;
/*
* scheduler clock - returns current time in nanosec units.
*/
unsigned long long sched_clock(void)
{
union {
unsigned long long ll;
unsigned l[2];
} tsc64, result;
unsigned long tmp;
unsigned product[3]; /* 96-bit intermediate value */
/* cnt32_to_63() is not safe with preemption */
preempt_disable();
/* expand the tsc to 64-bits.
* - sched_clock() must be called once a minute or better or the
* following will go horribly wrong - see cnt32_to_63()
*/
tsc64.ll = cnt32_to_63(get_cycles()) & 0x7fffffffffffffffULL;
preempt_enable();
/* scale the 64-bit TSC value to a nanosecond value via a 96-bit
* intermediate
*/
asm("mulu %2,%0,%3,%0 \n" /* LSW * mult -> 0:%3:%0 */
"mulu %2,%1,%2,%1 \n" /* MSW * mult -> %2:%1:0 */
"add %3,%1 \n"
"addc 0,%2 \n" /* result in %2:%1:%0 */
: "=r"(product[0]), "=r"(product[1]), "=r"(product[2]), "=r"(tmp)
: "0"(tsc64.l[0]), "1"(tsc64.l[1]), "2"(sched_clock_multiplier)
: "cc");
result.l[0] = product[1] << 16 | product[0] >> 16;
result.l[1] = product[2] << 16 | product[1] >> 16;
return result.ll;
}
/*
* initialise the scheduler clock
*/
static void __init mn10300_sched_clock_init(void)
{
sched_clock_multiplier =
__muldiv64u(NSEC_PER_SEC, 1 << 16, MN10300_TSCCLK);
}
/**
* local_timer_interrupt - Local timer interrupt handler
*
* Handle local timer interrupts for this CPU. They may have been propagated
* to this CPU from the CPU that actually gets them by way of an IPI.
*/
irqreturn_t local_timer_interrupt(void)
{
profile_tick(CPU_PROFILING);
update_process_times(user_mode(get_irq_regs()));
return IRQ_HANDLED;
}
#ifndef CONFIG_GENERIC_TIME
/*
* advance the kernel's time keeping clocks (xtime and jiffies)
* - we use Timer 0 & 1 cascaded as a clock to nudge us the next time
* there's a need to update
*/
static irqreturn_t timer_interrupt(int irq, void *dev_id)
{
unsigned tsc, elapse;
irqreturn_t ret;
write_seqlock(&xtime_lock);
while (tsc = get_cycles(),
elapse = tsc - mn10300_last_tsc, /* time elapsed since last
* tick */
elapse > MN10300_TSC_PER_HZ
) {
mn10300_last_tsc += MN10300_TSC_PER_HZ;
/* advance the kernel's time tracking system */
do_timer(1);
}
write_sequnlock(&xtime_lock);
ret = local_timer_interrupt();
#ifdef CONFIG_SMP
send_IPI_allbutself(LOCAL_TIMER_IPI);
#endif
return ret;
}
static struct irqaction timer_irq = {
.handler = timer_interrupt,
.flags = IRQF_DISABLED | IRQF_SHARED | IRQF_TIMER,
.name = "timer",
};
#endif /* CONFIG_GENERIC_TIME */
#ifdef CONFIG_CSRC_MN10300
void __init clocksource_set_clock(struct clocksource *cs, unsigned int clock)
{
u64 temp;
u32 shift;
/* Find a shift value */
for (shift = 32; shift > 0; shift--) {
temp = (u64) NSEC_PER_SEC << shift;
do_div(temp, clock);
if ((temp >> 32) == 0)
break;
}
cs->shift = shift;
cs->mult = (u32) temp;
}
#endif
#if CONFIG_CEVT_MN10300
void __cpuinit clockevent_set_clock(struct clock_event_device *cd,
unsigned int clock)
{
u64 temp;
u32 shift;
/* Find a shift value */
for (shift = 32; shift > 0; shift--) {
temp = (u64) clock << shift;
do_div(temp, NSEC_PER_SEC);
if ((temp >> 32) == 0)
break;
}
cd->shift = shift;
cd->mult = (u32) temp;
}
#endif
/*
* initialise the various timers used by the main part of the kernel
*/
void __init time_init(void)
{
/* we need the prescalar running to be able to use IOCLK/8
* - IOCLK runs at 1/4 (ST5 open) or 1/8 (ST5 closed) internal CPU clock
* - IOCLK runs at Fosc rate (crystal speed)
*/
TMPSCNT |= TMPSCNT_ENABLE;
#ifdef CONFIG_GENERIC_TIME
init_clocksource();
#else
startup_timestamp_counter();
#endif
printk(KERN_INFO
"timestamp counter I/O clock running at %lu.%02lu"
" (calibrated against RTC)\n",
MN10300_TSCCLK / 1000000, (MN10300_TSCCLK / 10000) % 100);
mn10300_last_tsc = read_timestamp_counter();
#ifdef CONFIG_GENERIC_CLOCKEVENTS
init_clockevents();
#else
reload_jiffies_counter(MN10300_JC_PER_HZ - 1);
setup_jiffies_interrupt(TMJCIRQ, &timer_irq, CONFIG_TIMER_IRQ_LEVEL);
#endif
#ifdef CONFIG_MN10300_WD_TIMER
/* start the watchdog timer */
watchdog_go();
#endif
mn10300_sched_clock_init();
}
|
