arch/arm/mach-highbank/hotplug.c

   1 /*
   2  * Copyright 2011 Calxeda, Inc.
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms and conditions of the GNU General Public License,
   6  * version 2, as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program.  If not, see <http://www.gnu.org/licenses/>.
  15  */
  16 #include <linux/kernel.h>
  17 #include <linux/errno.h>
  18 #include <linux/smp.h>
  19
  20 #include <asm/smp_scu.h>
  21 #include <asm/cacheflush.h>
  22
  23 #include "core.h"
  24
  25 extern void secondary_startup(void);
  26
  27 int platform_cpu_kill(unsigned int cpu)
  28 {
  29         return 1;
  30 }
  31
  32 /*
  33  * platform-specific code to shutdown a CPU
  34  *
  35  */
  36 void platform_cpu_die(unsigned int cpu)
  37 {
  38         flush_cache_all();
  39
  40         highbank_set_cpu_jump(cpu, secondary_startup);
  41         scu_power_mode(scu_base_addr, SCU_PM_POWEROFF);
  42
  43         cpu_do_idle();
  44
  45         /* We should never return from idle */
  46         panic("highbank: cpu %d unexpectedly exit from shutdown\n", cpu);
  47 }
  48
  49 int platform_cpu_disable(unsigned int cpu)
  50 {
  51         /*
  52          * CPU0 should not be shut down via hotplug.  cpu_idle can WFI
  53          * or a proper shutdown or hibernate should be used.
  54          */
  55         return cpu == 0 ? -EPERM : 0;
  56 }