hotplug.c 1.4 KB

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  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. #include <asm/smp_scu.h>
  20. #include <asm/cacheflush.h>
  21. #include "core.h"
  22. extern void secondary_startup(void);
  23. int platform_cpu_kill(unsigned int cpu)
  24. {
  25. return 1;
  26. }
  27. /*
  28. * platform-specific code to shutdown a CPU
  29. *
  30. */
  31. void platform_cpu_die(unsigned int cpu)
  32. {
  33. flush_cache_all();
  34. highbank_set_cpu_jump(cpu, secondary_startup);
  35. scu_power_mode(scu_base_addr, SCU_PM_POWEROFF);
  36. cpu_do_idle();
  37. /* We should never return from idle */
  38. panic("highbank: cpu %d unexpectedly exit from shutdown\n", cpu);
  39. }
  40. int platform_cpu_disable(unsigned int cpu)
  41. {
  42. /*
  43. * CPU0 should not be shut down via hotplug. cpu_idle can WFI
  44. * or a proper shutdown or hibernate should be used.
  45. */
  46. return cpu == 0 ? -EPERM : 0;
  47. }