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/pfn.h> 10#include <asm/system.h> 11 12/* 13 * References to section boundaries 14 */ 15extern const void __nosave_begin, __nosave_end; 16 17int pfn_is_nosave(unsigned long pfn) 18{ 19 unsigned long nosave_begin_pfn = PFN_DOWN(__pa(&__nosave_begin)); 20 unsigned long nosave_end_pfn = PFN_DOWN(__pa(&__nosave_end)); 21 22 /* Always save lowcore pages (LC protection might be enabled). */ 23 if (pfn <= LC_PAGES) 24 return 0; 25 if (pfn >= nosave_begin_pfn && pfn < nosave_end_pfn) 26 return 1; 27 /* Skip memory holes and read-only pages (NSS, DCSS, ...). */ 28 if (tprot(PFN_PHYS(pfn))) 29 return 1; 30 return 0; 31} 32 33void save_processor_state(void) 34{ 35 /* swsusp_arch_suspend() actually saves all cpu register contents. 36 * Machine checks must be disabled since swsusp_arch_suspend() stores 37 * register contents to their lowcore save areas. That's the same 38 * place where register contents on machine checks would be saved. 39 * To avoid register corruption disable machine checks. 40 * We must also disable machine checks in the new psw mask for 41 * program checks, since swsusp_arch_suspend() may generate program 42 * checks. Disabling machine checks for all other new psw masks is 43 * just paranoia. 44 */ 45 local_mcck_disable(); 46 /* Disable lowcore protection */ 47 __ctl_clear_bit(0,28); 48 S390_lowcore.external_new_psw.mask &= ~PSW_MASK_MCHECK; 49 S390_lowcore.svc_new_psw.mask &= ~PSW_MASK_MCHECK; 50 S390_lowcore.io_new_psw.mask &= ~PSW_MASK_MCHECK; 51 S390_lowcore.program_new_psw.mask &= ~PSW_MASK_MCHECK; 52} 53 54void restore_processor_state(void) 55{ 56 S390_lowcore.external_new_psw.mask |= PSW_MASK_MCHECK; 57 S390_lowcore.svc_new_psw.mask |= PSW_MASK_MCHECK; 58 S390_lowcore.io_new_psw.mask |= PSW_MASK_MCHECK; 59 S390_lowcore.program_new_psw.mask |= PSW_MASK_MCHECK; 60 /* Enable lowcore protection */ 61 __ctl_set_bit(0,28); 62 local_mcck_enable(); 63} 64