arch/s390/power/swsusp.c

   1 /*
   2  * Support for suspend and resume on s390
   3  *
   4  * Copyright IBM Corp. 2009
   5  *
   6  * Author(s): Hans-Joachim Picht <hans@linux.vnet.ibm.com>
   7  *
   8  */
   9
  10 #include <asm/system.h>
  11
  12 void save_processor_state(void)
  13 {
  14         /* swsusp_arch_suspend() actually saves all cpu register contents.
  15          * Machine checks must be disabled since swsusp_arch_suspend() stores
  16          * register contents to their lowcore save areas. That's the same
  17          * place where register contents on machine checks would be saved.
  18          * To avoid register corruption disable machine checks.
  19          * We must also disable machine checks in the new psw mask for
  20          * program checks, since swsusp_arch_suspend() may generate program
  21          * checks. Disabling machine checks for all other new psw masks is
  22          * just paranoia.
  23          */
  24         local_mcck_disable();
  25         /* Disable lowcore protection */
  26         __ctl_clear_bit(0,28);
  27         S390_lowcore.external_new_psw.mask &= ~PSW_MASK_MCHECK;
  28         S390_lowcore.svc_new_psw.mask &= ~PSW_MASK_MCHECK;
  29         S390_lowcore.io_new_psw.mask &= ~PSW_MASK_MCHECK;
  30         S390_lowcore.program_new_psw.mask &= ~PSW_MASK_MCHECK;
  31 }
  32
  33 void restore_processor_state(void)
  34 {
  35         S390_lowcore.external_new_psw.mask |= PSW_MASK_MCHECK;
  36         S390_lowcore.svc_new_psw.mask |= PSW_MASK_MCHECK;
  37         S390_lowcore.io_new_psw.mask |= PSW_MASK_MCHECK;
  38         S390_lowcore.program_new_psw.mask |= PSW_MASK_MCHECK;
  39         /* Enable lowcore protection */
  40         __ctl_set_bit(0,28);
  41         local_mcck_enable();
  42 }