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