1/* 2 * CPU hotplug support for CSR Marco dual-core SMP SoCs 3 * 4 * Copyright (c) 2012 Cambridge Silicon Radio Limited, a CSR plc group company. 5 * 6 * Licensed under GPLv2 or later. 7 */ 8 9#include <linux/kernel.h> 10#include <linux/errno.h> 11#include <linux/smp.h> 12 13#include <asm/smp_plat.h> 14 15static inline void platform_do_lowpower(unsigned int cpu) 16{ 17 /* we put the platform to just WFI */ 18 for (;;) { 19 __asm__ __volatile__("dsb\n\t" "wfi\n\t" 20 : : : "memory"); 21 if (pen_release == cpu_logical_map(cpu)) { 22 /* 23 * OK, proper wakeup, we're done 24 */ 25 break; 26 } 27 } 28} 29 30/* 31 * platform-specific code to shutdown a CPU 32 * 33 * Called with IRQs disabled 34 */ 35void __ref sirfsoc_cpu_die(unsigned int cpu) 36{ 37 platform_do_lowpower(cpu); 38} 39