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1 | /* |
2 | * linux/arch/arm/mach-cintegrator/platsmp.c | |
3 | * | |
4 | * Copyright (C) 2002 ARM Ltd. | |
5 | * All Rights Reserved | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License version 2 as | |
9 | * published by the Free Software Foundation. | |
10 | */ | |
11 | #include <linux/init.h> | |
12 | #include <linux/kernel.h> | |
13 | #include <linux/sched.h> | |
14 | #include <linux/errno.h> | |
15 | #include <linux/mm.h> | |
16 | ||
17 | #include <asm/atomic.h> | |
7ac5ae4b | 18 | #include <asm/cacheflush.h> |
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19 | #include <asm/delay.h> |
20 | #include <asm/mmu_context.h> | |
21 | #include <asm/procinfo.h> | |
22 | #include <asm/ptrace.h> | |
23 | #include <asm/smp.h> | |
24 | ||
25 | extern void integrator_secondary_startup(void); | |
26 | ||
27 | /* | |
28 | * control for which core is the next to come out of the secondary | |
29 | * boot "holding pen" | |
30 | */ | |
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31 | volatile int __cpuinitdata pen_release = -1; |
32 | unsigned long __cpuinitdata phys_pen_release = 0; | |
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33 | |
34 | static DEFINE_SPINLOCK(boot_lock); | |
35 | ||
bd6f68af | 36 | void __cpuinit platform_secondary_init(unsigned int cpu) |
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37 | { |
38 | /* | |
39 | * the primary core may have used a "cross call" soft interrupt | |
40 | * to get this processor out of WFI in the BootMonitor - make | |
41 | * sure that we are no longer being sent this soft interrupt | |
42 | */ | |
43 | smp_cross_call_done(cpumask_of_cpu(cpu)); | |
44 | ||
45 | /* | |
46 | * if any interrupts are already enabled for the primary | |
47 | * core (e.g. timer irq), then they will not have been enabled | |
48 | * for us: do so | |
49 | */ | |
50 | secondary_scan_irqs(); | |
51 | ||
52 | /* | |
53 | * let the primary processor know we're out of the | |
54 | * pen, then head off into the C entry point | |
55 | */ | |
56 | pen_release = -1; | |
57 | ||
58 | /* | |
59 | * Synchronise with the boot thread. | |
60 | */ | |
61 | spin_lock(&boot_lock); | |
62 | spin_unlock(&boot_lock); | |
63 | } | |
64 | ||
bd6f68af | 65 | int __cpuinit boot_secondary(unsigned int cpu, struct task_struct *idle) |
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66 | { |
67 | unsigned long timeout; | |
68 | ||
69 | /* | |
70 | * set synchronisation state between this boot processor | |
71 | * and the secondary one | |
72 | */ | |
73 | spin_lock(&boot_lock); | |
74 | ||
75 | /* | |
76 | * The secondary processor is waiting to be released from | |
77 | * the holding pen - release it, then wait for it to flag | |
78 | * that it has been released by resetting pen_release. | |
79 | * | |
80 | * Note that "pen_release" is the hardware CPU ID, whereas | |
81 | * "cpu" is Linux's internal ID. | |
82 | */ | |
83 | pen_release = cpu; | |
7ac5ae4b | 84 | flush_cache_all(); |
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85 | |
86 | /* | |
87 | * XXX | |
88 | * | |
89 | * This is a later addition to the booting protocol: the | |
90 | * bootMonitor now puts secondary cores into WFI, so | |
91 | * poke_milo() no longer gets the cores moving; we need | |
92 | * to send a soft interrupt to wake the secondary core. | |
93 | * Use smp_cross_call() for this, since there's little | |
94 | * point duplicating the code here | |
95 | */ | |
96 | smp_cross_call(cpumask_of_cpu(cpu)); | |
97 | ||
98 | timeout = jiffies + (1 * HZ); | |
99 | while (time_before(jiffies, timeout)) { | |
100 | if (pen_release == -1) | |
101 | break; | |
102 | ||
103 | udelay(10); | |
104 | } | |
105 | ||
106 | /* | |
107 | * now the secondary core is starting up let it run its | |
108 | * calibrations, then wait for it to finish | |
109 | */ | |
110 | spin_unlock(&boot_lock); | |
111 | ||
112 | return pen_release != -1 ? -ENOSYS : 0; | |
113 | } | |
114 | ||
115 | static void __init poke_milo(void) | |
116 | { | |
117 | extern void secondary_startup(void); | |
118 | ||
119 | /* nobody is to be released from the pen yet */ | |
120 | pen_release = -1; | |
121 | ||
122 | phys_pen_release = virt_to_phys(&pen_release); | |
123 | ||
124 | /* | |
125 | * write the address of secondary startup into the system-wide | |
126 | * flags register, then clear the bottom two bits, which is what | |
127 | * BootMonitor is waiting for | |
128 | */ | |
129 | #if 1 | |
130 | #define CINTEGRATOR_HDR_FLAGSS_OFFSET 0x30 | |
131 | __raw_writel(virt_to_phys(integrator_secondary_startup), | |
132 | (IO_ADDRESS(INTEGRATOR_HDR_BASE) + | |
133 | CINTEGRATOR_HDR_FLAGSS_OFFSET)); | |
134 | #define CINTEGRATOR_HDR_FLAGSC_OFFSET 0x34 | |
135 | __raw_writel(3, | |
136 | (IO_ADDRESS(INTEGRATOR_HDR_BASE) + | |
137 | CINTEGRATOR_HDR_FLAGSC_OFFSET)); | |
138 | #endif | |
139 | ||
140 | mb(); | |
141 | } | |
142 | ||
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143 | /* |
144 | * Initialise the CPU possible map early - this describes the CPUs | |
145 | * which may be present or become present in the system. | |
146 | */ | |
147 | void __init smp_init_cpus(void) | |
148 | { | |
149 | unsigned int i, ncores = get_core_count(); | |
150 | ||
151 | for (i = 0; i < ncores; i++) | |
152 | cpu_set(i, cpu_possible_map); | |
153 | } | |
154 | ||
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155 | void __init smp_prepare_cpus(unsigned int max_cpus) |
156 | { | |
157 | unsigned int ncores = get_core_count(); | |
158 | unsigned int cpu = smp_processor_id(); | |
159 | int i; | |
160 | ||
161 | /* sanity check */ | |
162 | if (ncores == 0) { | |
163 | printk(KERN_ERR | |
164 | "Integrator/CP: strange CM count of 0? Default to 1\n"); | |
165 | ||
166 | ncores = 1; | |
167 | } | |
168 | ||
169 | if (ncores > NR_CPUS) { | |
170 | printk(KERN_WARNING | |
171 | "Integrator/CP: no. of cores (%d) greater than configured " | |
172 | "maximum of %d - clipping\n", | |
173 | ncores, NR_CPUS); | |
174 | ncores = NR_CPUS; | |
175 | } | |
176 | ||
177 | /* | |
178 | * start with some more config for the Boot CPU, now that | |
179 | * the world is a bit more alive (which was not the case | |
180 | * when smp_prepare_boot_cpu() was called) | |
181 | */ | |
182 | smp_store_cpu_info(cpu); | |
183 | ||
184 | /* | |
185 | * are we trying to boot more cores than exist? | |
186 | */ | |
187 | if (max_cpus > ncores) | |
188 | max_cpus = ncores; | |
189 | ||
190 | /* | |
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191 | * Initialise the present map, which describes the set of CPUs |
192 | * actually populated at the present time. | |
fe6ef2da | 193 | */ |
7bbb7940 | 194 | for (i = 0; i < max_cpus; i++) |
73eb7d9e | 195 | cpu_set(i, cpu_present_map); |
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196 | |
197 | /* | |
198 | * Do we need any more CPUs? If so, then let them know where | |
199 | * to start. Note that, on modern versions of MILO, the "poke" | |
200 | * doesn't actually do anything until each individual core is | |
201 | * sent a soft interrupt to get it out of WFI | |
202 | */ | |
203 | if (max_cpus > 1) | |
204 | poke_milo(); | |
205 | } |