1 /* 2 * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License version 2 as 6 * published by the Free Software Foundation. 7 */ 8 9 #include <linux/kernel.h> 10 #include <linux/mm.h> 11 #include <linux/bootmem.h> 12 #include <linux/memblock.h> 13 #ifdef CONFIG_BLK_DEV_INITRD 14 #include <linux/initrd.h> 15 #endif 16 #include <linux/of_fdt.h> 17 #include <linux/swap.h> 18 #include <linux/module.h> 19 #include <linux/highmem.h> 20 #include <asm/page.h> 21 #include <asm/pgalloc.h> 22 #include <asm/sections.h> 23 #include <asm/arcregs.h> 24 25 pgd_t swapper_pg_dir[PTRS_PER_PGD] __aligned(PAGE_SIZE); 26 char empty_zero_page[PAGE_SIZE] __aligned(PAGE_SIZE); 27 EXPORT_SYMBOL(empty_zero_page); 28 29 static const unsigned long low_mem_start = CONFIG_LINUX_LINK_BASE; 30 static unsigned long low_mem_sz; 31 32 #ifdef CONFIG_HIGHMEM 33 static unsigned long min_high_pfn, max_high_pfn; 34 static u64 high_mem_start; 35 static u64 high_mem_sz; 36 #endif 37 38 #ifdef CONFIG_DISCONTIGMEM 39 struct pglist_data node_data[MAX_NUMNODES] __read_mostly; 40 EXPORT_SYMBOL(node_data); 41 #endif 42 43 /* User can over-ride above with "mem=nnn[KkMm]" in cmdline */ 44 static int __init setup_mem_sz(char *str) 45 { 46 low_mem_sz = memparse(str, NULL) & PAGE_MASK; 47 48 /* early console might not be setup yet - it will show up later */ 49 pr_info("\"mem=%s\": mem sz set to %ldM\n", str, TO_MB(low_mem_sz)); 50 51 return 0; 52 } 53 early_param("mem", setup_mem_sz); 54 55 void __init early_init_dt_add_memory_arch(u64 base, u64 size) 56 { 57 int in_use = 0; 58 59 if (!low_mem_sz) { 60 if (base != low_mem_start) 61 panic("CONFIG_LINUX_LINK_BASE != DT memory { }"); 62 63 low_mem_sz = size; 64 in_use = 1; 65 } else { 66 #ifdef CONFIG_HIGHMEM 67 high_mem_start = base; 68 high_mem_sz = size; 69 in_use = 1; 70 #endif 71 } 72 73 pr_info("Memory @ %llx [%lldM] %s\n", 74 base, TO_MB(size), !in_use ? "Not used":""); 75 } 76 77 #ifdef CONFIG_BLK_DEV_INITRD 78 static int __init early_initrd(char *p) 79 { 80 unsigned long start, size; 81 char *endp; 82 83 start = memparse(p, &endp); 84 if (*endp == ',') { 85 size = memparse(endp + 1, NULL); 86 87 initrd_start = (unsigned long)__va(start); 88 initrd_end = (unsigned long)__va(start + size); 89 } 90 return 0; 91 } 92 early_param("initrd", early_initrd); 93 #endif 94 95 /* 96 * First memory setup routine called from setup_arch() 97 * 1. setup swapper's mm @init_mm 98 * 2. Count the pages we have and setup bootmem allocator 99 * 3. zone setup 100 */ 101 void __init setup_arch_memory(void) 102 { 103 unsigned long zones_size[MAX_NR_ZONES]; 104 unsigned long zones_holes[MAX_NR_ZONES]; 105 106 init_mm.start_code = (unsigned long)_text; 107 init_mm.end_code = (unsigned long)_etext; 108 init_mm.end_data = (unsigned long)_edata; 109 init_mm.brk = (unsigned long)_end; 110 111 /* first page of system - kernel .vector starts here */ 112 min_low_pfn = ARCH_PFN_OFFSET; 113 114 /* Last usable page of low mem */ 115 max_low_pfn = max_pfn = PFN_DOWN(low_mem_start + low_mem_sz); 116 117 #ifdef CONFIG_FLATMEM 118 /* pfn_valid() uses this */ 119 max_mapnr = max_low_pfn - min_low_pfn; 120 #endif 121 122 /*------------- bootmem allocator setup -----------------------*/ 123 124 /* 125 * seed the bootmem allocator after any DT memory node parsing or 126 * "mem=xxx" cmdline overrides have potentially updated @arc_mem_sz 127 * 128 * Only low mem is added, otherwise we have crashes when allocating 129 * mem_map[] itself. NO_BOOTMEM allocates mem_map[] at the end of 130 * avail memory, ending in highmem with a > 32-bit address. However 131 * it then tries to memset it with a truncaed 32-bit handle, causing 132 * the crash 133 */ 134 135 memblock_add_node(low_mem_start, low_mem_sz, 0); 136 memblock_reserve(low_mem_start, __pa(_end) - low_mem_start); 137 138 #ifdef CONFIG_BLK_DEV_INITRD 139 if (initrd_start) 140 memblock_reserve(__pa(initrd_start), initrd_end - initrd_start); 141 #endif 142 143 early_init_fdt_reserve_self(); 144 early_init_fdt_scan_reserved_mem(); 145 146 memblock_dump_all(); 147 148 /*----------------- node/zones setup --------------------------*/ 149 memset(zones_size, 0, sizeof(zones_size)); 150 memset(zones_holes, 0, sizeof(zones_holes)); 151 152 zones_size[ZONE_NORMAL] = max_low_pfn - min_low_pfn; 153 zones_holes[ZONE_NORMAL] = 0; 154 155 /* 156 * We can't use the helper free_area_init(zones[]) because it uses 157 * PAGE_OFFSET to compute the @min_low_pfn which would be wrong 158 * when our kernel doesn't start at PAGE_OFFSET, i.e. 159 * PAGE_OFFSET != CONFIG_LINUX_LINK_BASE 160 */ 161 free_area_init_node(0, /* node-id */ 162 zones_size, /* num pages per zone */ 163 min_low_pfn, /* first pfn of node */ 164 zones_holes); /* holes */ 165 166 #ifdef CONFIG_HIGHMEM 167 /* 168 * Populate a new node with highmem 169 * 170 * On ARC (w/o PAE) HIGHMEM addresses are actually smaller (0 based) 171 * than addresses in normal ala low memory (0x8000_0000 based). 172 * Even with PAE, the huge peripheral space hole would waste a lot of 173 * mem with single mem_map[]. This warrants a mem_map per region design. 174 * Thus HIGHMEM on ARC is imlemented with DISCONTIGMEM. 175 * 176 * DISCONTIGMEM in turns requires multiple nodes. node 0 above is 177 * populated with normal memory zone while node 1 only has highmem 178 */ 179 node_set_online(1); 180 181 min_high_pfn = PFN_DOWN(high_mem_start); 182 max_high_pfn = PFN_DOWN(high_mem_start + high_mem_sz); 183 184 zones_size[ZONE_NORMAL] = 0; 185 zones_holes[ZONE_NORMAL] = 0; 186 187 zones_size[ZONE_HIGHMEM] = max_high_pfn - min_high_pfn; 188 zones_holes[ZONE_HIGHMEM] = 0; 189 190 free_area_init_node(1, /* node-id */ 191 zones_size, /* num pages per zone */ 192 min_high_pfn, /* first pfn of node */ 193 zones_holes); /* holes */ 194 195 high_memory = (void *)(min_high_pfn << PAGE_SHIFT); 196 kmap_init(); 197 #endif 198 } 199 200 /* 201 * mem_init - initializes memory 202 * 203 * Frees up bootmem 204 * Calculates and displays memory available/used 205 */ 206 void __init mem_init(void) 207 { 208 #ifdef CONFIG_HIGHMEM 209 unsigned long tmp; 210 211 reset_all_zones_managed_pages(); 212 for (tmp = min_high_pfn; tmp < max_high_pfn; tmp++) 213 free_highmem_page(pfn_to_page(tmp)); 214 #endif 215 216 free_all_bootmem(); 217 mem_init_print_info(NULL); 218 } 219 220 /* 221 * free_initmem: Free all the __init memory. 222 */ 223 void __init_refok free_initmem(void) 224 { 225 free_initmem_default(-1); 226 } 227 228 #ifdef CONFIG_BLK_DEV_INITRD 229 void __init free_initrd_mem(unsigned long start, unsigned long end) 230 { 231 free_reserved_area((void *)start, (void *)end, -1, "initrd"); 232 } 233 #endif 234