1 /* linux arch/arm/mach-s5pv310/hotplug.c
3 * Cloned from linux/arch/arm/mach-realview/hotplug.c
5 * Copyright (C) 2002 ARM Ltd.
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
13 #include <linux/kernel.h>
14 #include <linux/errno.h>
15 #include <linux/smp.h>
16 #include <linux/completion.h>
18 #include <asm/cacheflush.h>
20 extern volatile int pen_release;
22 static DECLARE_COMPLETION(cpu_killed);
24 static inline void cpu_enter_lowpower(void)
30 " mcr p15, 0, %1, c7, c5, 0\n"
31 " mcr p15, 0, %1, c7, c10, 4\n"
35 " mrc p15, 0, %0, c1, c0, 1\n"
36 " bic %0, %0, #0x20\n"
37 " mcr p15, 0, %0, c1, c0, 1\n"
38 " mrc p15, 0, %0, c1, c0, 0\n"
39 " bic %0, %0, #0x04\n"
40 " mcr p15, 0, %0, c1, c0, 0\n"
46 static inline void cpu_leave_lowpower(void)
51 "mrc p15, 0, %0, c1, c0, 0\n"
52 " orr %0, %0, #0x04\n"
53 " mcr p15, 0, %0, c1, c0, 0\n"
54 " mrc p15, 0, %0, c1, c0, 1\n"
55 " orr %0, %0, #0x20\n"
56 " mcr p15, 0, %0, c1, c0, 1\n"
62 static inline void platform_do_lowpower(unsigned int cpu)
65 * there is no power-control hardware on this platform, so all
66 * we can do is put the core into WFI; this is safe as the calling
67 * code will have already disabled interrupts
73 asm(".word 0xe320f003\n"
78 if (pen_release == cpu) {
80 * OK, proper wakeup, we're done
86 * getting here, means that we have come out of WFI without
87 * having been woken up - this shouldn't happen
89 * The trouble is, letting people know about this is not really
90 * possible, since we are currently running incoherently, and
91 * therefore cannot safely call printk() or anything else
94 printk(KERN_WARN "CPU%u: spurious wakeup call\n", cpu);
99 int platform_cpu_kill(unsigned int cpu)
101 return wait_for_completion_timeout(&cpu_killed, 5000);
105 * platform-specific code to shutdown a CPU
107 * Called with IRQs disabled
109 void platform_cpu_die(unsigned int cpu)
112 unsigned int this_cpu = hard_smp_processor_id();
114 if (cpu != this_cpu) {
115 printk(KERN_CRIT "Eek! platform_cpu_die running on %u, should be %u\n",
121 printk(KERN_NOTICE "CPU%u: shutdown\n", cpu);
122 complete(&cpu_killed);
125 * we're ready for shutdown now, so do it
127 cpu_enter_lowpower();
128 platform_do_lowpower(cpu);
131 * bring this CPU back into the world of cache
132 * coherency, and then restore interrupts
134 cpu_leave_lowpower();
137 int platform_cpu_disable(unsigned int cpu)
140 * we don't allow CPU 0 to be shutdown (it is still too special
141 * e.g. clock tick interrupts)
143 return cpu == 0 ? -EPERM : 0;