v4.19.13 snapshot.
diff --git a/arch/arc/mm/init.c b/arch/arc/mm/init.c
new file mode 100644
index 0000000..ba14506
--- /dev/null
+++ b/arch/arc/mm/init.c
@@ -0,0 +1,238 @@
+/*
+ * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/bootmem.h>
+#include <linux/memblock.h>
+#ifdef CONFIG_BLK_DEV_INITRD
+#include <linux/initrd.h>
+#endif
+#include <linux/of_fdt.h>
+#include <linux/swap.h>
+#include <linux/module.h>
+#include <linux/highmem.h>
+#include <asm/page.h>
+#include <asm/pgalloc.h>
+#include <asm/sections.h>
+#include <asm/arcregs.h>
+
+pgd_t swapper_pg_dir[PTRS_PER_PGD] __aligned(PAGE_SIZE);
+char empty_zero_page[PAGE_SIZE] __aligned(PAGE_SIZE);
+EXPORT_SYMBOL(empty_zero_page);
+
+static const unsigned long low_mem_start = CONFIG_LINUX_RAM_BASE;
+static unsigned long low_mem_sz;
+
+#ifdef CONFIG_HIGHMEM
+static unsigned long min_high_pfn, max_high_pfn;
+static u64 high_mem_start;
+static u64 high_mem_sz;
+#endif
+
+#ifdef CONFIG_DISCONTIGMEM
+struct pglist_data node_data[MAX_NUMNODES] __read_mostly;
+EXPORT_SYMBOL(node_data);
+#endif
+
+long __init arc_get_mem_sz(void)
+{
+ return low_mem_sz;
+}
+
+/* User can over-ride above with "mem=nnn[KkMm]" in cmdline */
+static int __init setup_mem_sz(char *str)
+{
+ low_mem_sz = memparse(str, NULL) & PAGE_MASK;
+
+ /* early console might not be setup yet - it will show up later */
+ pr_info("\"mem=%s\": mem sz set to %ldM\n", str, TO_MB(low_mem_sz));
+
+ return 0;
+}
+early_param("mem", setup_mem_sz);
+
+void __init early_init_dt_add_memory_arch(u64 base, u64 size)
+{
+ int in_use = 0;
+
+ if (!low_mem_sz) {
+ if (base != low_mem_start)
+ panic("CONFIG_LINUX_RAM_BASE != DT memory { }");
+
+ low_mem_sz = size;
+ in_use = 1;
+ } else {
+#ifdef CONFIG_HIGHMEM
+ high_mem_start = base;
+ high_mem_sz = size;
+ in_use = 1;
+#endif
+ }
+
+ pr_info("Memory @ %llx [%lldM] %s\n",
+ base, TO_MB(size), !in_use ? "Not used":"");
+}
+
+#ifdef CONFIG_BLK_DEV_INITRD
+static int __init early_initrd(char *p)
+{
+ unsigned long start, size;
+ char *endp;
+
+ start = memparse(p, &endp);
+ if (*endp == ',') {
+ size = memparse(endp + 1, NULL);
+
+ initrd_start = (unsigned long)__va(start);
+ initrd_end = (unsigned long)__va(start + size);
+ }
+ return 0;
+}
+early_param("initrd", early_initrd);
+#endif
+
+/*
+ * First memory setup routine called from setup_arch()
+ * 1. setup swapper's mm @init_mm
+ * 2. Count the pages we have and setup bootmem allocator
+ * 3. zone setup
+ */
+void __init setup_arch_memory(void)
+{
+ unsigned long zones_size[MAX_NR_ZONES];
+ unsigned long zones_holes[MAX_NR_ZONES];
+
+ init_mm.start_code = (unsigned long)_text;
+ init_mm.end_code = (unsigned long)_etext;
+ init_mm.end_data = (unsigned long)_edata;
+ init_mm.brk = (unsigned long)_end;
+
+ /* first page of system - kernel .vector starts here */
+ min_low_pfn = ARCH_PFN_OFFSET;
+
+ /* Last usable page of low mem */
+ max_low_pfn = max_pfn = PFN_DOWN(low_mem_start + low_mem_sz);
+
+#ifdef CONFIG_FLATMEM
+ /* pfn_valid() uses this */
+ max_mapnr = max_low_pfn - min_low_pfn;
+#endif
+
+ /*------------- bootmem allocator setup -----------------------*/
+
+ /*
+ * seed the bootmem allocator after any DT memory node parsing or
+ * "mem=xxx" cmdline overrides have potentially updated @arc_mem_sz
+ *
+ * Only low mem is added, otherwise we have crashes when allocating
+ * mem_map[] itself. NO_BOOTMEM allocates mem_map[] at the end of
+ * avail memory, ending in highmem with a > 32-bit address. However
+ * it then tries to memset it with a truncaed 32-bit handle, causing
+ * the crash
+ */
+
+ memblock_add_node(low_mem_start, low_mem_sz, 0);
+ memblock_reserve(low_mem_start, __pa(_end) - low_mem_start);
+
+#ifdef CONFIG_BLK_DEV_INITRD
+ if (initrd_start)
+ memblock_reserve(__pa(initrd_start), initrd_end - initrd_start);
+#endif
+
+ early_init_fdt_reserve_self();
+ early_init_fdt_scan_reserved_mem();
+
+ memblock_dump_all();
+
+ /*----------------- node/zones setup --------------------------*/
+ memset(zones_size, 0, sizeof(zones_size));
+ memset(zones_holes, 0, sizeof(zones_holes));
+
+ zones_size[ZONE_NORMAL] = max_low_pfn - min_low_pfn;
+ zones_holes[ZONE_NORMAL] = 0;
+
+ /*
+ * We can't use the helper free_area_init(zones[]) because it uses
+ * PAGE_OFFSET to compute the @min_low_pfn which would be wrong
+ * when our kernel doesn't start at PAGE_OFFSET, i.e.
+ * PAGE_OFFSET != CONFIG_LINUX_RAM_BASE
+ */
+ free_area_init_node(0, /* node-id */
+ zones_size, /* num pages per zone */
+ min_low_pfn, /* first pfn of node */
+ zones_holes); /* holes */
+
+#ifdef CONFIG_HIGHMEM
+ /*
+ * Populate a new node with highmem
+ *
+ * On ARC (w/o PAE) HIGHMEM addresses are actually smaller (0 based)
+ * than addresses in normal ala low memory (0x8000_0000 based).
+ * Even with PAE, the huge peripheral space hole would waste a lot of
+ * mem with single mem_map[]. This warrants a mem_map per region design.
+ * Thus HIGHMEM on ARC is imlemented with DISCONTIGMEM.
+ *
+ * DISCONTIGMEM in turns requires multiple nodes. node 0 above is
+ * populated with normal memory zone while node 1 only has highmem
+ */
+ node_set_online(1);
+
+ min_high_pfn = PFN_DOWN(high_mem_start);
+ max_high_pfn = PFN_DOWN(high_mem_start + high_mem_sz);
+
+ zones_size[ZONE_NORMAL] = 0;
+ zones_holes[ZONE_NORMAL] = 0;
+
+ zones_size[ZONE_HIGHMEM] = max_high_pfn - min_high_pfn;
+ zones_holes[ZONE_HIGHMEM] = 0;
+
+ free_area_init_node(1, /* node-id */
+ zones_size, /* num pages per zone */
+ min_high_pfn, /* first pfn of node */
+ zones_holes); /* holes */
+
+ high_memory = (void *)(min_high_pfn << PAGE_SHIFT);
+ kmap_init();
+#endif
+}
+
+/*
+ * mem_init - initializes memory
+ *
+ * Frees up bootmem
+ * Calculates and displays memory available/used
+ */
+void __init mem_init(void)
+{
+#ifdef CONFIG_HIGHMEM
+ unsigned long tmp;
+
+ reset_all_zones_managed_pages();
+ for (tmp = min_high_pfn; tmp < max_high_pfn; tmp++)
+ free_highmem_page(pfn_to_page(tmp));
+#endif
+
+ free_all_bootmem();
+ mem_init_print_info(NULL);
+}
+
+/*
+ * free_initmem: Free all the __init memory.
+ */
+void __ref free_initmem(void)
+{
+ free_initmem_default(-1);
+}
+
+#ifdef CONFIG_BLK_DEV_INITRD
+void __init free_initrd_mem(unsigned long start, unsigned long end)
+{
+ free_reserved_area((void *)start, (void *)end, -1, "initrd");
+}
+#endif