1 files changed, 73 insertions, 0 deletions

diff --git a/arch/s390/kernel/suspend.c b/arch/s390/kernel/suspend.c
new file mode 100644
index 000000000000..086bee970cae
--- /dev/null
+++ b/arch/s390/kernel/suspend.c
@@ -0,0 +1,73 @@
+/*
+ * Suspend support specific for s390.
+ *
+ * Copyright IBM Corp. 2009
+ *
+ * Author(s): Hans-Joachim Picht <hans@linux.vnet.ibm.com>
+ */
+
+#include <linux/suspend.h>
+#include <linux/reboot.h>
+#include <linux/pfn.h>
+#include <linux/mm.h>
+#include <asm/sections.h>
+#include <asm/system.h>
+#include <asm/ipl.h>
+
+/*
+ * References to section boundaries
+ */
+extern const void __nosave_begin, __nosave_end;
+
+/*
+ *  check if given pfn is in the 'nosave' or in the read only NSS section
+ */
+int pfn_is_nosave(unsigned long pfn)
+{
+        unsigned long nosave_begin_pfn = __pa(&__nosave_begin) >> PAGE_SHIFT;
+        unsigned long nosave_end_pfn = PAGE_ALIGN(__pa(&__nosave_end))
+                                        >> PAGE_SHIFT;
+        unsigned long eshared_pfn = PFN_DOWN(__pa(&_eshared)) - 1;
+        unsigned long stext_pfn = PFN_DOWN(__pa(&_stext));
+
+        if (pfn >= nosave_begin_pfn && pfn < nosave_end_pfn)
+                return 1;
+        if (pfn >= stext_pfn && pfn <= eshared_pfn) {
+                if (ipl_info.type == IPL_TYPE_NSS)
+                        return 1;
+        } else if ((tprot(pfn * PAGE_SIZE) && pfn > 0))
+                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();
+}