arch/arm/mach-prima2/hotplug.c

   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/cacheflush.h>
  14 #include <asm/smp_plat.h>
  15
  16 static inline void platform_do_lowpower(unsigned int cpu)
  17 {
  18         flush_cache_all();
  19
  20         /* we put the platform to just WFI */
  21         for (;;) {
  22                 __asm__ __volatile__("dsb\n\t" "wfi\n\t"
  23                         : : : "memory");
  24                 if (pen_release == cpu_logical_map(cpu)) {
  25                         /*
  26                          * OK, proper wakeup, we're done
  27                          */
  28                         break;
  29                 }
  30         }
  31 }
  32
  33 /*
  34  * platform-specific code to shutdown a CPU
  35  *
  36  * Called with IRQs disabled
  37  */
  38 void __ref sirfsoc_cpu_die(unsigned int cpu)
  39 {
  40         platform_do_lowpower(cpu);
  41 }