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
211
212
213
214
215
216
217
218
219
220
221
|
/*
* linux/arch/arm/mach-realview/platsmp.c
*
* Copyright (C) 2002 ARM Ltd.
* All Rights Reserved
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/jiffies.h>
#include <linux/smp.h>
#include <linux/io.h>
#include <asm/cacheflush.h>
#include <mach/hardware.h>
#include <asm/mach-types.h>
#include <asm/localtimer.h>
#include <asm/unified.h>
#include <mach/board-eb.h>
#include <mach/board-pb11mp.h>
#include <mach/board-pbx.h>
#include <asm/smp_scu.h>
#include "core.h"
extern void realview_secondary_startup(void);
/*
* control for which core is the next to come out of the secondary
* boot "holding pen"
*/
volatile int __cpuinitdata pen_release = -1;
static void __iomem *scu_base_addr(void)
{
if (machine_is_realview_eb_mp())
return __io_address(REALVIEW_EB11MP_SCU_BASE);
else if (machine_is_realview_pb11mp())
return __io_address(REALVIEW_TC11MP_SCU_BASE);
else if (machine_is_realview_pbx() &&
(core_tile_pbx11mp() || core_tile_pbxa9mp()))
return __io_address(REALVIEW_PBX_TILE_SCU_BASE);
else
return (void __iomem *)0;
}
static inline unsigned int get_core_count(void)
{
void __iomem *scu_base = scu_base_addr();
if (scu_base)
return scu_get_core_count(scu_base);
return 1;
}
static DEFINE_SPINLOCK(boot_lock);
void __cpuinit platform_secondary_init(unsigned int cpu)
{
trace_hardirqs_off();
/*
* if any interrupts are already enabled for the primary
* core (e.g. timer irq), then they will not have been enabled
* for us: do so
*/
gic_cpu_init(0, gic_cpu_base_addr);
/*
* let the primary processor know we're out of the
* pen, then head off into the C entry point
*/
pen_release = -1;
smp_wmb();
/*
* Synchronise with the boot thread.
*/
spin_lock(&boot_lock);
spin_unlock(&boot_lock);
}
int __cpuinit boot_secondary(unsigned int cpu, struct task_struct *idle)
{
unsigned long timeout;
/*
* set synchronisation state between this boot processor
* and the secondary one
*/
spin_lock(&boot_lock);
/*
* The secondary processor is waiting to be released from
* the holding pen - release it, then wait for it to flag
* that it has been released by resetting pen_release.
*
* Note that "pen_release" is the hardware CPU ID, whereas
* "cpu" is Linux's internal ID.
*/
pen_release = cpu;
flush_cache_all();
/*
* XXX
*
* This is a later addition to the booting protocol: the
* bootMonitor now puts secondary cores into WFI, so
* poke_milo() no longer gets the cores moving; we need
* to send a soft interrupt to wake the secondary core.
* Use smp_cross_call() for this, since there's little
* point duplicating the code here
*/
smp_cross_call(cpumask_of(cpu), 1);
timeout = jiffies + (1 * HZ);
while (time_before(jiffies, timeout)) {
smp_rmb();
if (pen_release == -1)
break;
udelay(10);
}
/*
* now the secondary core is starting up let it run its
* calibrations, then wait for it to finish
*/
spin_unlock(&boot_lock);
return pen_release != -1 ? -ENOSYS : 0;
}
static void __init poke_milo(void)
{
/* nobody is to be released from the pen yet */
pen_release = -1;
/*
* Write the address of secondary startup into the system-wide flags
* register. The BootMonitor waits for this register to become
* non-zero.
*/
__raw_writel(BSYM(virt_to_phys(realview_secondary_startup)),
__io_address(REALVIEW_SYS_FLAGSSET));
mb();
}
/*
* Initialise the CPU possible map early - this describes the CPUs
* which may be present or become present in the system.
*/
void __init smp_init_cpus(void)
{
unsigned int i, ncores = get_core_count();
for (i = 0; i < ncores; i++)
set_cpu_possible(i, true);
}
void __init smp_prepare_cpus(unsigned int max_cpus)
{
unsigned int ncores = get_core_count();
unsigned int cpu = smp_processor_id();
int i;
/* sanity check */
if (ncores == 0) {
printk(KERN_ERR
"Realview: strange CM count of 0? Default to 1\n");
ncores = 1;
}
if (ncores > NR_CPUS) {
printk(KERN_WARNING
"Realview: no. of cores (%d) greater than configured "
"maximum of %d - clipping\n",
ncores, NR_CPUS);
ncores = NR_CPUS;
}
smp_store_cpu_info(cpu);
/*
* are we trying to boot more cores than exist?
*/
if (max_cpus > ncores)
max_cpus = ncores;
/*
* Initialise the present map, which describes the set of CPUs
* actually populated at the present time.
*/
for (i = 0; i < max_cpus; i++)
set_cpu_present(i, true);
/*
* Initialise the SCU if there are more than one CPU and let
* them know where to start. Note that, on modern versions of
* MILO, the "poke" doesn't actually do anything until each
* individual core is sent a soft interrupt to get it out of
* WFI
*/
if (max_cpus > 1) {
/*
* Enable the local timer or broadcast device for the
* boot CPU, but only if we have more than one CPU.
*/
percpu_timer_setup();
scu_enable(scu_base_addr());
poke_milo();
}
}
|
