v4.19.13 snapshot.
diff --git a/arch/s390/kernel/suspend.c b/arch/s390/kernel/suspend.c
new file mode 100644
index 0000000..75b7b30
--- /dev/null
+++ b/arch/s390/kernel/suspend.c
@@ -0,0 +1,240 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Suspend support specific for s390.
+ *
+ * Copyright IBM Corp. 2009
+ *
+ * Author(s): Hans-Joachim Picht <hans@linux.vnet.ibm.com>
+ */
+
+#include <linux/pfn.h>
+#include <linux/suspend.h>
+#include <linux/mm.h>
+#include <linux/pci.h>
+#include <asm/ctl_reg.h>
+#include <asm/ipl.h>
+#include <asm/cio.h>
+#include <asm/sections.h>
+#include "entry.h"
+
+/*
+ * The restore of the saved pages in an hibernation image will set
+ * the change and referenced bits in the storage key for each page.
+ * Overindication of the referenced bits after an hibernation cycle
+ * does not cause any harm but the overindication of the change bits
+ * would cause trouble.
+ * Use the ARCH_SAVE_PAGE_KEYS hooks to save the storage key of each
+ * page to the most significant byte of the associated page frame
+ * number in the hibernation image.
+ */
+
+/*
+ * Key storage is allocated as a linked list of pages.
+ * The size of the keys array is (PAGE_SIZE - sizeof(long))
+ */
+struct page_key_data {
+ struct page_key_data *next;
+ unsigned char data[];
+};
+
+#define PAGE_KEY_DATA_SIZE (PAGE_SIZE - sizeof(struct page_key_data *))
+
+static struct page_key_data *page_key_data;
+static struct page_key_data *page_key_rp, *page_key_wp;
+static unsigned long page_key_rx, page_key_wx;
+unsigned long suspend_zero_pages;
+
+/*
+ * For each page in the hibernation image one additional byte is
+ * stored in the most significant byte of the page frame number.
+ * On suspend no additional memory is required but on resume the
+ * keys need to be memorized until the page data has been restored.
+ * Only then can the storage keys be set to their old state.
+ */
+unsigned long page_key_additional_pages(unsigned long pages)
+{
+ return DIV_ROUND_UP(pages, PAGE_KEY_DATA_SIZE);
+}
+
+/*
+ * Free page_key_data list of arrays.
+ */
+void page_key_free(void)
+{
+ struct page_key_data *pkd;
+
+ while (page_key_data) {
+ pkd = page_key_data;
+ page_key_data = pkd->next;
+ free_page((unsigned long) pkd);
+ }
+}
+
+/*
+ * Allocate page_key_data list of arrays with enough room to store
+ * one byte for each page in the hibernation image.
+ */
+int page_key_alloc(unsigned long pages)
+{
+ struct page_key_data *pk;
+ unsigned long size;
+
+ size = DIV_ROUND_UP(pages, PAGE_KEY_DATA_SIZE);
+ while (size--) {
+ pk = (struct page_key_data *) get_zeroed_page(GFP_KERNEL);
+ if (!pk) {
+ page_key_free();
+ return -ENOMEM;
+ }
+ pk->next = page_key_data;
+ page_key_data = pk;
+ }
+ page_key_rp = page_key_wp = page_key_data;
+ page_key_rx = page_key_wx = 0;
+ return 0;
+}
+
+/*
+ * Save the storage key into the upper 8 bits of the page frame number.
+ */
+void page_key_read(unsigned long *pfn)
+{
+ struct page *page;
+ unsigned long addr;
+ unsigned char key;
+
+ page = pfn_to_page(*pfn);
+ addr = (unsigned long) page_address(page);
+ key = (unsigned char) page_get_storage_key(addr) & 0x7f;
+ if (arch_test_page_nodat(page))
+ key |= 0x80;
+ *(unsigned char *) pfn = key;
+}
+
+/*
+ * Extract the storage key from the upper 8 bits of the page frame number
+ * and store it in the page_key_data list of arrays.
+ */
+void page_key_memorize(unsigned long *pfn)
+{
+ page_key_wp->data[page_key_wx] = *(unsigned char *) pfn;
+ *(unsigned char *) pfn = 0;
+ if (++page_key_wx < PAGE_KEY_DATA_SIZE)
+ return;
+ page_key_wp = page_key_wp->next;
+ page_key_wx = 0;
+}
+
+/*
+ * Get the next key from the page_key_data list of arrays and set the
+ * storage key of the page referred by @address. If @address refers to
+ * a "safe" page the swsusp_arch_resume code will transfer the storage
+ * key from the buffer page to the original page.
+ */
+void page_key_write(void *address)
+{
+ struct page *page;
+ unsigned char key;
+
+ key = page_key_rp->data[page_key_rx];
+ page_set_storage_key((unsigned long) address, key & 0x7f, 0);
+ page = virt_to_page(address);
+ if (key & 0x80)
+ arch_set_page_nodat(page, 0);
+ else
+ arch_set_page_dat(page, 0);
+ if (++page_key_rx >= PAGE_KEY_DATA_SIZE)
+ return;
+ page_key_rp = page_key_rp->next;
+ page_key_rx = 0;
+}
+
+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));
+ unsigned long end_rodata_pfn = PFN_DOWN(__pa(__end_rodata)) - 1;
+ unsigned long stext_pfn = PFN_DOWN(__pa(_stext));
+
+ /* 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 (DCSS, ...). */
+ if (pfn >= stext_pfn && pfn <= end_rodata_pfn)
+ return 0;
+ if (tprot(PFN_PHYS(pfn)))
+ return 1;
+ return 0;
+}
+
+/*
+ * PM notifier callback for suspend
+ */
+static int suspend_pm_cb(struct notifier_block *nb, unsigned long action,
+ void *ptr)
+{
+ switch (action) {
+ case PM_SUSPEND_PREPARE:
+ case PM_HIBERNATION_PREPARE:
+ suspend_zero_pages = __get_free_pages(GFP_KERNEL, LC_ORDER);
+ if (!suspend_zero_pages)
+ return NOTIFY_BAD;
+ break;
+ case PM_POST_SUSPEND:
+ case PM_POST_HIBERNATION:
+ free_pages(suspend_zero_pages, LC_ORDER);
+ break;
+ default:
+ return NOTIFY_DONE;
+ }
+ return NOTIFY_OK;
+}
+
+static int __init suspend_pm_init(void)
+{
+ pm_notifier(suspend_pm_cb, 0);
+ return 0;
+}
+arch_initcall(suspend_pm_init);
+
+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();
+}
+
+/* Called at the end of swsusp_arch_resume */
+void s390_early_resume(void)
+{
+ lgr_info_log();
+ channel_subsystem_reinit();
+ zpci_rescan();
+}