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* linux/arch/arm/mach-realview/hotplug.c
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* Copyright (C) 2002 ARM Ltd.
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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#include <linux/kernel.h>
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#include <linux/errno.h>
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#include <linux/smp.h>
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#include <asm/cacheflush.h>
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static inline void cpu_enter_lowpower(void)
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" mcr p15, 0, %1, c7, c5, 0\n"
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" mcr p15, 0, %1, c7, c10, 4\n"
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" mrc p15, 0, %0, c1, c0, 1\n"
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" bic %0, %0, #0x20\n"
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" mcr p15, 0, %0, c1, c0, 1\n"
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" mrc p15, 0, %0, c1, c0, 0\n"
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" mcr p15, 0, %0, c1, c0, 0\n"
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: "r" (0), "Ir" (CR_C)
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static inline void cpu_leave_lowpower(void)
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"mrc p15, 0, %0, c1, c0, 0\n"
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" mcr p15, 0, %0, c1, c0, 0\n"
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" mrc p15, 0, %0, c1, c0, 1\n"
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" orr %0, %0, #0x20\n"
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" mcr p15, 0, %0, c1, c0, 1\n"
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static inline void platform_do_lowpower(unsigned int cpu, int *spurious)
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* there is no power-control hardware on this platform, so all
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* we can do is put the core into WFI; this is safe as the calling
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* code will have already disabled interrupts
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asm(".word 0xe320f003\n"
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/*if (pen_release == cpu) {*/
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* OK, proper wakeup, we're done
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* Getting here, means that we have come out of WFI without
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* having been woken up - this shouldn't happen
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* Just note it happening - when we're woken, we can report
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int platform_cpu_kill(unsigned int cpu)
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* platform-specific code to shutdown a CPU
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* Called with IRQs disabled
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void platform_cpu_die(unsigned int cpu)
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* we're ready for shutdown now, so do it
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cpu_enter_lowpower();
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platform_do_lowpower(cpu, &spurious);
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* bring this CPU back into the world of cache
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* coherency, and then restore interrupts
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cpu_leave_lowpower();
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pr_warn("CPU%u: %u spurious wakeup calls\n", cpu, spurious);
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int platform_cpu_disable(unsigned int cpu)
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* we don't allow CPU 0 to be shutdown (it is still too special
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* e.g. clock tick interrupts)
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return cpu == 0 ? -EPERM : 0;