/* * Suspend support specific for s390. * * Copyright IBM Corp. 2009 * * Author(s): Hans-Joachim Picht <hans@linux.vnet.ibm.com> */ #include <linux/pfn.h> #include <asm/system.h> /* * References to section boundaries */ extern const void __nosave_begin, __nosave_end; int pfn_is_nosave(unsigned long pfn) { unsigned long nosave_begin_pfn = PFN_DOWN(__pa(&__nosave_begin)); unsigned long nosave_end_pfn = PFN_DOWN(__pa(&__nosave_end)); /* Always save lowcore pages (LC protection might be enabled). */ if (pfn <= LC_PAGES) return 0; if (pfn >= nosave_begin_pfn && pfn < nosave_end_pfn) return 1; /* Skip memory holes and read-only pages (NSS, DCSS, ...). */ if (tprot(PFN_PHYS(pfn))) return 1; return 0; } void save_processor_state(void) { /* swsusp_arch_suspend() actually saves all cpu register contents. * Machine checks must be disabled since swsusp_arch_suspend() stores * register contents to their lowcore save areas. That's the same * place where register contents on machine checks would be saved. * To avoid register corruption disable machine checks. * We must also disable machine checks in the new psw mask for * program checks, since swsusp_arch_suspend() may generate program * checks. Disabling machine checks for all other new psw masks is * just paranoia. */ local_mcck_disable(); /* Disable lowcore protection */ __ctl_clear_bit(0,28); S390_lowcore.external_new_psw.mask &= ~PSW_MASK_MCHECK; S390_lowcore.svc_new_psw.mask &= ~PSW_MASK_MCHECK; S390_lowcore.io_new_psw.mask &= ~PSW_MASK_MCHECK; S390_lowcore.program_new_psw.mask &= ~PSW_MASK_MCHECK; } void restore_processor_state(void) { S390_lowcore.external_new_psw.mask |= PSW_MASK_MCHECK; S390_lowcore.svc_new_psw.mask |= PSW_MASK_MCHECK; S390_lowcore.io_new_psw.mask |= PSW_MASK_MCHECK; S390_lowcore.program_new_psw.mask |= PSW_MASK_MCHECK; /* Enable lowcore protection */ __ctl_set_bit(0,28); local_mcck_enable(); }