arch/arc/mm/init.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
   4  */
   5
   6 #include <linux/kernel.h>
   7 #include <linux/mm.h>
   8 #include <linux/memblock.h>
   9 #ifdef CONFIG_BLK_DEV_INITRD
  10 #include <linux/initrd.h>
  11 #endif
  12 #include <linux/of_fdt.h>
  13 #include <linux/swap.h>
  14 #include <linux/module.h>
  15 #include <linux/highmem.h>
  16 #include <asm/page.h>
  17 #include <asm/pgalloc.h>
  18 #include <asm/sections.h>
  19 #include <asm/arcregs.h>
  20
  21 pgd_t swapper_pg_dir[PTRS_PER_PGD] __aligned(PAGE_SIZE);
  22 char empty_zero_page[PAGE_SIZE] __aligned(PAGE_SIZE);
  23 EXPORT_SYMBOL(empty_zero_page);
  24
  25 static const unsigned long low_mem_start = CONFIG_LINUX_RAM_BASE;
  26 static unsigned long low_mem_sz;
  27
  28 #ifdef CONFIG_HIGHMEM
  29 static unsigned long min_high_pfn, max_high_pfn;
  30 static u64 high_mem_start;
  31 static u64 high_mem_sz;
  32 #endif
  33
  34 #ifdef CONFIG_DISCONTIGMEM
  35 struct pglist_data node_data[MAX_NUMNODES] __read_mostly;
  36 EXPORT_SYMBOL(node_data);
  37 #endif
  38
  39 long __init arc_get_mem_sz(void)
  40 {
  41         return low_mem_sz;
  42 }
  43
  44 /* User can over-ride above with "mem=nnn[KkMm]" in cmdline */
  45 static int __init setup_mem_sz(char *str)
  46 {
  47         low_mem_sz = memparse(str, NULL) & PAGE_MASK;
  48
  49         /* early console might not be setup yet - it will show up later */
  50         pr_info("\"mem=%s\": mem sz set to %ldM\n", str, TO_MB(low_mem_sz));
  51
  52         return 0;
  53 }
  54 early_param("mem", setup_mem_sz);
  55
  56 void __init early_init_dt_add_memory_arch(u64 base, u64 size)
  57 {
  58         int in_use = 0;
  59
  60         if (!low_mem_sz) {
  61                 if (base != low_mem_start)
  62                         panic("CONFIG_LINUX_RAM_BASE != DT memory { }");
  63
  64                 low_mem_sz = size;
  65                 in_use = 1;
  66         } else {
  67 #ifdef CONFIG_HIGHMEM
  68                 high_mem_start = base;
  69                 high_mem_sz = size;
  70                 in_use = 1;
  71 #endif
  72         }
  73
  74         pr_info("Memory @ %llx [%lldM] %s\n",
  75                 base, TO_MB(size), !in_use ? "Not used":"");
  76 }
  77
  78 /*
  79  * First memory setup routine called from setup_arch()
  80  * 1. setup swapper's mm @init_mm
  81  * 2. Count the pages we have and setup bootmem allocator
  82  * 3. zone setup
  83  */
  84 void __init setup_arch_memory(void)
  85 {
  86         unsigned long zones_size[MAX_NR_ZONES];
  87         unsigned long zones_holes[MAX_NR_ZONES];
  88
  89         init_mm.start_code = (unsigned long)_text;
  90         init_mm.end_code = (unsigned long)_etext;
  91         init_mm.end_data = (unsigned long)_edata;
  92         init_mm.brk = (unsigned long)_end;
  93
  94         /* first page of system - kernel .vector starts here */
  95         min_low_pfn = ARCH_PFN_OFFSET;
  96
  97         /* Last usable page of low mem */
  98         max_low_pfn = max_pfn = PFN_DOWN(low_mem_start + low_mem_sz);
  99
 100 #ifdef CONFIG_FLATMEM
 101         /* pfn_valid() uses this */
 102         max_mapnr = max_low_pfn - min_low_pfn;
 103 #endif
 104
 105         /*------------- bootmem allocator setup -----------------------*/
 106
 107         /*
 108          * seed the bootmem allocator after any DT memory node parsing or
 109          * "mem=xxx" cmdline overrides have potentially updated @arc_mem_sz
 110          *
 111          * Only low mem is added, otherwise we have crashes when allocating
 112          * mem_map[] itself. NO_BOOTMEM allocates mem_map[] at the end of
 113          * avail memory, ending in highmem with a > 32-bit address. However
 114          * it then tries to memset it with a truncaed 32-bit handle, causing
 115          * the crash
 116          */
 117
 118         memblock_add_node(low_mem_start, low_mem_sz, 0);
 119         memblock_reserve(CONFIG_LINUX_LINK_BASE,
 120                          __pa(_end) - CONFIG_LINUX_LINK_BASE);
 121
 122 #ifdef CONFIG_BLK_DEV_INITRD
 123         if (phys_initrd_size) {
 124                 memblock_reserve(phys_initrd_start, phys_initrd_size);
 125                 initrd_start = (unsigned long)__va(phys_initrd_start);
 126                 initrd_end = initrd_start + phys_initrd_size;
 127         }
 128 #endif
 129
 130         early_init_fdt_reserve_self();
 131         early_init_fdt_scan_reserved_mem();
 132
 133         memblock_dump_all();
 134
 135         /*----------------- node/zones setup --------------------------*/
 136         memset(zones_size, 0, sizeof(zones_size));
 137         memset(zones_holes, 0, sizeof(zones_holes));
 138
 139         zones_size[ZONE_NORMAL] = max_low_pfn - min_low_pfn;
 140         zones_holes[ZONE_NORMAL] = 0;
 141
 142         /*
 143          * We can't use the helper free_area_init(zones[]) because it uses
 144          * PAGE_OFFSET to compute the @min_low_pfn which would be wrong
 145          * when our kernel doesn't start at PAGE_OFFSET, i.e.
 146          * PAGE_OFFSET != CONFIG_LINUX_RAM_BASE
 147          */
 148         free_area_init_node(0,                  /* node-id */
 149                             zones_size,         /* num pages per zone */
 150                             min_low_pfn,        /* first pfn of node */
 151                             zones_holes);       /* holes */
 152
 153 #ifdef CONFIG_HIGHMEM
 154         /*
 155          * Populate a new node with highmem
 156          *
 157          * On ARC (w/o PAE) HIGHMEM addresses are actually smaller (0 based)
 158          * than addresses in normal ala low memory (0x8000_0000 based).
 159          * Even with PAE, the huge peripheral space hole would waste a lot of
 160          * mem with single mem_map[]. This warrants a mem_map per region design.
 161          * Thus HIGHMEM on ARC is imlemented with DISCONTIGMEM.
 162          *
 163          * DISCONTIGMEM in turns requires multiple nodes. node 0 above is
 164          * populated with normal memory zone while node 1 only has highmem
 165          */
 166         node_set_online(1);
 167
 168         min_high_pfn = PFN_DOWN(high_mem_start);
 169         max_high_pfn = PFN_DOWN(high_mem_start + high_mem_sz);
 170
 171         zones_size[ZONE_NORMAL] = 0;
 172         zones_holes[ZONE_NORMAL] = 0;
 173
 174         zones_size[ZONE_HIGHMEM] = max_high_pfn - min_high_pfn;
 175         zones_holes[ZONE_HIGHMEM] = 0;
 176
 177         free_area_init_node(1,                  /* node-id */
 178                             zones_size,         /* num pages per zone */
 179                             min_high_pfn,       /* first pfn of node */
 180                             zones_holes);       /* holes */
 181
 182         high_memory = (void *)(min_high_pfn << PAGE_SHIFT);
 183         kmap_init();
 184 #endif
 185 }
 186
 187 /*
 188  * mem_init - initializes memory
 189  *
 190  * Frees up bootmem
 191  * Calculates and displays memory available/used
 192  */
 193 void __init mem_init(void)
 194 {
 195 #ifdef CONFIG_HIGHMEM
 196         unsigned long tmp;
 197
 198         reset_all_zones_managed_pages();
 199         for (tmp = min_high_pfn; tmp < max_high_pfn; tmp++)
 200                 free_highmem_page(pfn_to_page(tmp));
 201 #endif
 202
 203         memblock_free_all();
 204         mem_init_print_info(NULL);
 205 }