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
|
/*
* Copyright (C) 2000, 2001 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
* sb1250 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/sb1250.h>
#include <asm/sibyte/sb1250_regs.h>
#include <asm/sibyte/sb1250_int.h>
#include <asm/sibyte/sb1250_scd.h>
#define IMR_IP2_VAL K_INT_MAP_I0
#define IMR_IP3_VAL K_INT_MAP_I1
#define IMR_IP4_VAL K_INT_MAP_I2
#define SB1250_HPT_NUM 3
#define SB1250_HPT_VALUE M_SCD_TIMER_CNT /* max value */
#define SB1250_HPT_SHIFT ((sizeof(unsigned int)*8)-V_SCD_TIMER_WIDTH)
extern int sb1250_steal_irq(int irq);
static unsigned int sb1250_hpt_read(void);
static void sb1250_hpt_init(unsigned int);
static unsigned int hpt_offset;
void __init sb1250_hpt_setup(void)
{
int cpu = smp_processor_id();
if (!cpu) {
/* Setup hpt using timer #3 but do not enable irq for it */
__raw_writeq(0, IOADDR(A_SCD_TIMER_REGISTER(SB1250_HPT_NUM, R_SCD_TIMER_CFG)));
__raw_writeq(SB1250_HPT_VALUE,
IOADDR(A_SCD_TIMER_REGISTER(SB1250_HPT_NUM, R_SCD_TIMER_INIT)));
__raw_writeq(M_SCD_TIMER_ENABLE | M_SCD_TIMER_MODE_CONTINUOUS,
IOADDR(A_SCD_TIMER_REGISTER(SB1250_HPT_NUM, R_SCD_TIMER_CFG)));
/*
* we need to fill 32 bits, so just use the upper 23 bits and pretend
* the timer is going 512Mhz instead of 1Mhz
*/
mips_hpt_frequency = V_SCD_TIMER_FREQ << SB1250_HPT_SHIFT;
mips_hpt_init = sb1250_hpt_init;
mips_hpt_read = sb1250_hpt_read;
}
}
void sb1250_time_init(void)
{
int cpu = smp_processor_id();
int irq = K_INT_TIMER_0+cpu;
/* Only have 4 general purpose timers, and we use last one as hpt */
if (cpu > 2) {
BUG();
}
sb1250_mask_irq(cpu, irq);
/* Map the timer interrupt to ip[4] of this cpu */
__raw_writeq(IMR_IP4_VAL,
IOADDR(A_IMR_REGISTER(cpu, R_IMR_INTERRUPT_MAP_BASE) +
(irq << 3)));
/* the general purpose timer ticks at 1 Mhz independent if 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)));
#ifdef CONFIG_SIMULATION
__raw_writeq((50000 / HZ) - 1,
IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_INIT)));
#else
__raw_writeq((V_SCD_TIMER_FREQ / HZ) - 1,
IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_INIT)));
#endif
/* 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)));
sb1250_unmask_irq(cpu, irq);
sb1250_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. sb1250_timer_interrupt is
* called directly from irq_handler.S when IP[4] is set during an
* interrupt
*/
}
void sb1250_timer_interrupt(struct pt_regs *regs)
{
int cpu = smp_processor_id();
int irq = K_INT_TIMER_0 + cpu;
/* ACK interrupt */
____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);
}
}
/*
* The HPT is free running from SB1250_HPT_VALUE down to 0 then starts over
* again. There's no easy way to set to a specific value so store init value
* in hpt_offset and subtract each time.
*
* Note: Timer isn't full 32bits so shift it into the upper part making
* it appear to run at a higher frequency.
*/
static unsigned int sb1250_hpt_read(void)
{
unsigned int count;
count = G_SCD_TIMER_CNT(__raw_readq(IOADDR(A_SCD_TIMER_REGISTER(SB1250_HPT_NUM, R_SCD_TIMER_CNT))));
count = (SB1250_HPT_VALUE - count) << SB1250_HPT_SHIFT;
return count - hpt_offset;
}
static void sb1250_hpt_init(unsigned int count)
{
hpt_offset = count;
return;
}
|
