v4.19.13 snapshot.
diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
new file mode 100644
index 0000000..3fa3e53
--- /dev/null
+++ b/arch/s390/mm/init.c
@@ -0,0 +1,253 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * S390 version
+ * Copyright IBM Corp. 1999
+ * Author(s): Hartmut Penner (hp@de.ibm.com)
+ *
+ * Derived from "arch/i386/mm/init.c"
+ * Copyright (C) 1995 Linus Torvalds
+ */
+
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/ptrace.h>
+#include <linux/mman.h>
+#include <linux/mm.h>
+#include <linux/swap.h>
+#include <linux/smp.h>
+#include <linux/init.h>
+#include <linux/pagemap.h>
+#include <linux/bootmem.h>
+#include <linux/memory.h>
+#include <linux/pfn.h>
+#include <linux/poison.h>
+#include <linux/initrd.h>
+#include <linux/export.h>
+#include <linux/cma.h>
+#include <linux/gfp.h>
+#include <linux/memblock.h>
+#include <asm/processor.h>
+#include <linux/uaccess.h>
+#include <asm/pgtable.h>
+#include <asm/pgalloc.h>
+#include <asm/dma.h>
+#include <asm/lowcore.h>
+#include <asm/tlb.h>
+#include <asm/tlbflush.h>
+#include <asm/sections.h>
+#include <asm/ctl_reg.h>
+#include <asm/sclp.h>
+#include <asm/set_memory.h>
+
+pgd_t swapper_pg_dir[PTRS_PER_PGD] __section(.bss..swapper_pg_dir);
+
+unsigned long empty_zero_page, zero_page_mask;
+EXPORT_SYMBOL(empty_zero_page);
+EXPORT_SYMBOL(zero_page_mask);
+
+static void __init setup_zero_pages(void)
+{
+ unsigned int order;
+ struct page *page;
+ int i;
+
+ /* Latest machines require a mapping granularity of 512KB */
+ order = 7;
+
+ /* Limit number of empty zero pages for small memory sizes */
+ while (order > 2 && (totalram_pages >> 10) < (1UL << order))
+ order--;
+
+ empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
+ if (!empty_zero_page)
+ panic("Out of memory in setup_zero_pages");
+
+ page = virt_to_page((void *) empty_zero_page);
+ split_page(page, order);
+ for (i = 1 << order; i > 0; i--) {
+ mark_page_reserved(page);
+ page++;
+ }
+
+ zero_page_mask = ((PAGE_SIZE << order) - 1) & PAGE_MASK;
+}
+
+/*
+ * paging_init() sets up the page tables
+ */
+void __init paging_init(void)
+{
+ unsigned long max_zone_pfns[MAX_NR_ZONES];
+ unsigned long pgd_type, asce_bits;
+ psw_t psw;
+
+ init_mm.pgd = swapper_pg_dir;
+ if (VMALLOC_END > _REGION2_SIZE) {
+ asce_bits = _ASCE_TYPE_REGION2 | _ASCE_TABLE_LENGTH;
+ pgd_type = _REGION2_ENTRY_EMPTY;
+ } else {
+ asce_bits = _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH;
+ pgd_type = _REGION3_ENTRY_EMPTY;
+ }
+ init_mm.context.asce = (__pa(init_mm.pgd) & PAGE_MASK) | asce_bits;
+ S390_lowcore.kernel_asce = init_mm.context.asce;
+ S390_lowcore.user_asce = S390_lowcore.kernel_asce;
+ crst_table_init((unsigned long *) init_mm.pgd, pgd_type);
+ vmem_map_init();
+
+ /* enable virtual mapping in kernel mode */
+ __ctl_load(S390_lowcore.kernel_asce, 1, 1);
+ __ctl_load(S390_lowcore.kernel_asce, 7, 7);
+ __ctl_load(S390_lowcore.kernel_asce, 13, 13);
+ psw.mask = __extract_psw();
+ psw_bits(psw).dat = 1;
+ psw_bits(psw).as = PSW_BITS_AS_HOME;
+ __load_psw_mask(psw.mask);
+
+ sparse_memory_present_with_active_regions(MAX_NUMNODES);
+ sparse_init();
+ memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
+ max_zone_pfns[ZONE_DMA] = PFN_DOWN(MAX_DMA_ADDRESS);
+ max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
+ free_area_init_nodes(max_zone_pfns);
+}
+
+void mark_rodata_ro(void)
+{
+ unsigned long size = __end_ro_after_init - __start_ro_after_init;
+
+ set_memory_ro((unsigned long)__start_ro_after_init, size >> PAGE_SHIFT);
+ pr_info("Write protected read-only-after-init data: %luk\n", size >> 10);
+}
+
+void __init mem_init(void)
+{
+ cpumask_set_cpu(0, &init_mm.context.cpu_attach_mask);
+ cpumask_set_cpu(0, mm_cpumask(&init_mm));
+
+ set_max_mapnr(max_low_pfn);
+ high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
+
+ /* Setup guest page hinting */
+ cmma_init();
+
+ /* this will put all low memory onto the freelists */
+ free_all_bootmem();
+ setup_zero_pages(); /* Setup zeroed pages. */
+
+ cmma_init_nodat();
+
+ mem_init_print_info(NULL);
+}
+
+void free_initmem(void)
+{
+ __set_memory((unsigned long)_sinittext,
+ (unsigned long)(_einittext - _sinittext) >> PAGE_SHIFT,
+ SET_MEMORY_RW | SET_MEMORY_NX);
+ free_initmem_default(POISON_FREE_INITMEM);
+}
+
+#ifdef CONFIG_BLK_DEV_INITRD
+void __init free_initrd_mem(unsigned long start, unsigned long end)
+{
+ free_reserved_area((void *)start, (void *)end, POISON_FREE_INITMEM,
+ "initrd");
+}
+#endif
+
+unsigned long memory_block_size_bytes(void)
+{
+ /*
+ * Make sure the memory block size is always greater
+ * or equal than the memory increment size.
+ */
+ return max_t(unsigned long, MIN_MEMORY_BLOCK_SIZE, sclp.rzm);
+}
+
+#ifdef CONFIG_MEMORY_HOTPLUG
+
+#ifdef CONFIG_CMA
+
+/* Prevent memory blocks which contain cma regions from going offline */
+
+struct s390_cma_mem_data {
+ unsigned long start;
+ unsigned long end;
+};
+
+static int s390_cma_check_range(struct cma *cma, void *data)
+{
+ struct s390_cma_mem_data *mem_data;
+ unsigned long start, end;
+
+ mem_data = data;
+ start = cma_get_base(cma);
+ end = start + cma_get_size(cma);
+ if (end < mem_data->start)
+ return 0;
+ if (start >= mem_data->end)
+ return 0;
+ return -EBUSY;
+}
+
+static int s390_cma_mem_notifier(struct notifier_block *nb,
+ unsigned long action, void *data)
+{
+ struct s390_cma_mem_data mem_data;
+ struct memory_notify *arg;
+ int rc = 0;
+
+ arg = data;
+ mem_data.start = arg->start_pfn << PAGE_SHIFT;
+ mem_data.end = mem_data.start + (arg->nr_pages << PAGE_SHIFT);
+ if (action == MEM_GOING_OFFLINE)
+ rc = cma_for_each_area(s390_cma_check_range, &mem_data);
+ return notifier_from_errno(rc);
+}
+
+static struct notifier_block s390_cma_mem_nb = {
+ .notifier_call = s390_cma_mem_notifier,
+};
+
+static int __init s390_cma_mem_init(void)
+{
+ return register_memory_notifier(&s390_cma_mem_nb);
+}
+device_initcall(s390_cma_mem_init);
+
+#endif /* CONFIG_CMA */
+
+int arch_add_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap,
+ bool want_memblock)
+{
+ unsigned long start_pfn = PFN_DOWN(start);
+ unsigned long size_pages = PFN_DOWN(size);
+ int rc;
+
+ rc = vmem_add_mapping(start, size);
+ if (rc)
+ return rc;
+
+ rc = __add_pages(nid, start_pfn, size_pages, altmap, want_memblock);
+ if (rc)
+ vmem_remove_mapping(start, size);
+ return rc;
+}
+
+#ifdef CONFIG_MEMORY_HOTREMOVE
+int arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap)
+{
+ /*
+ * There is no hardware or firmware interface which could trigger a
+ * hot memory remove on s390. So there is nothing that needs to be
+ * implemented.
+ */
+ return -EBUSY;
+}
+#endif
+#endif /* CONFIG_MEMORY_HOTPLUG */