arch/s390/power/suspend.c

   1 /*
   2  * Suspend support specific for s390.
   3  *
   4  * Copyright IBM Corp. 2009
   5  *
   6  * Author(s): Hans-Joachim Picht <hans@linux.vnet.ibm.com>
   7  */
   8
   9 #include <linux/mm.h>
  10 #include <linux/suspend.h>
  11 #include <linux/reboot.h>
  12 #include <linux/pfn.h>
  13 #include <asm/sections.h>
  14 #include <asm/ipl.h>
  15
  16 /*
  17  * References to section boundaries
  18  */
  19 extern const void __nosave_begin, __nosave_end;
  20
  21 /*
  22  *  check if given pfn is in the 'nosave' or in the read only NSS section
  23  */
  24 int pfn_is_nosave(unsigned long pfn)
  25 {
  26         unsigned long nosave_begin_pfn = __pa(&__nosave_begin) >> PAGE_SHIFT;
  27         unsigned long nosave_end_pfn = PAGE_ALIGN(__pa(&__nosave_end))
  28                                         >> PAGE_SHIFT;
  29         unsigned long eshared_pfn = PFN_DOWN(__pa(&_eshared)) - 1;
  30         unsigned long stext_pfn = PFN_DOWN(__pa(&_stext));
  31
  32         if (pfn >= nosave_begin_pfn && pfn < nosave_end_pfn)
  33                 return 1;
  34         if (pfn >= stext_pfn && pfn <= eshared_pfn) {
  35                 if (ipl_info.type == IPL_TYPE_NSS)
  36                         return 1;
  37         } else if ((tprot(pfn * PAGE_SIZE) && pfn > 0))
  38                 return 1;
  39         return 0;
  40 }