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
|
/*
* Copyright (C) 2000,2001,2004 Broadcom Corporation
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
/*
* These are routines to set up and handle interrupts from the
* bcm1480 general purpose timer 0. We're using the timer as a
* system clock, so we set it up to run at 100 Hz. On every
* interrupt, we update our idea of what the time of day is,
* then call do_timer() in the architecture-independent kernel
* code to do general bookkeeping (e.g. update jiffies, run
* bottom halves, etc.)
*/
#include <linux/interrupt.h>
#include <linux/sched.h>
#include <linux/spinlock.h>
#include <linux/kernel_stat.h>
#include <asm/irq.h>
#include <asm/ptrace.h>
#include <asm/addrspace.h>
#include <asm/time.h>
#include <asm/io.h>
#include <asm/sibyte/bcm1480_regs.h>
#include <asm/sibyte/sb1250_regs.h>
#include <asm/sibyte/bcm1480_int.h>
#include <asm/sibyte/bcm1480_scd.h>
#include <asm/sibyte/sb1250.h>
#define IMR_IP2_VAL K_BCM1480_INT_MAP_I0
#define IMR_IP3_VAL K_BCM1480_INT_MAP_I1
#define IMR_IP4_VAL K_BCM1480_INT_MAP_I2
extern int bcm1480_steal_irq(int irq);
void bcm1480_time_init(void)
{
int cpu = smp_processor_id();
int irq = K_BCM1480_INT_TIMER_0+cpu;
/* Only have 4 general purpose timers */
if (cpu > 3) {
BUG();
}
if (!cpu) {
/* Use our own gettimeoffset() routine */
do_gettimeoffset = bcm1480_gettimeoffset;
}
bcm1480_mask_irq(cpu, irq);
/* Map the timer interrupt to ip[4] of this cpu */
__raw_writeq(IMR_IP4_VAL, IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_INTERRUPT_MAP_BASE_H)
+ (irq<<3)));
/* the general purpose timer ticks at 1 Mhz independent of the rest of the system */
/* Disable the timer and set up the count */
__raw_writeq(0, IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG)));
__raw_writeq(
#ifndef CONFIG_SIMULATION
1000000/HZ
#else
50000/HZ
#endif
, IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_INIT)));
/* Set the timer running */
__raw_writeq(M_SCD_TIMER_ENABLE|M_SCD_TIMER_MODE_CONTINUOUS,
IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG)));
bcm1480_unmask_irq(cpu, irq);
bcm1480_steal_irq(irq);
/*
* This interrupt is "special" in that it doesn't use the request_irq
* way to hook the irq line. The timer interrupt is initialized early
* enough to make this a major pain, and it's also firing enough to
* warrant a bit of special case code. bcm1480_timer_interrupt is
* called directly from irq_handler.S when IP[4] is set during an
* interrupt
*/
}
#include <asm/sibyte/sb1250.h>
void bcm1480_timer_interrupt(struct pt_regs *regs)
{
int cpu = smp_processor_id();
int irq = K_BCM1480_INT_TIMER_0+cpu;
/* Reset the timer */
__raw_writeq(M_SCD_TIMER_ENABLE|M_SCD_TIMER_MODE_CONTINUOUS,
IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG)));
if (cpu == 0) {
/*
* CPU 0 handles the global timer interrupt job
*/
ll_timer_interrupt(irq, regs);
}
else {
/*
* other CPUs should just do profiling and process accounting
*/
ll_local_timer_interrupt(irq, regs);
}
}
/*
* We use our own do_gettimeoffset() instead of the generic one,
* because the generic one does not work for SMP case.
* In addition, since we use general timer 0 for system time,
* we can get accurate intra-jiffy offset without calibration.
*/
unsigned long bcm1480_gettimeoffset(void)
{
unsigned long count =
__raw_readq(IOADDR(A_SCD_TIMER_REGISTER(0, R_SCD_TIMER_CNT)));
return 1000000/HZ - count;
}
|
