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/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_LINK_BASE; 29 static unsigned long low_mem_sz; 30 31 #ifdef CONFIG_HIGHMEM 32 static unsigned long min_high_pfn; 33 static u64 high_mem_start; 34 static u64 high_mem_sz; 35 #endif 36 37 /* User can over-ride above with "mem=nnn[KkMm]" in cmdline */ 38 static int __init setup_mem_sz(char *str) 39 { 40 low_mem_sz = memparse(str, NULL) & PAGE_MASK; 41 42 /* early console might not be setup yet - it will show up later */ 43 pr_info("\"mem=%s\": mem sz set to %ldM\n", str, TO_MB(low_mem_sz)); 44 45 return 0; 46 } 47 early_param("mem", setup_mem_sz); 48 49 void __init early_init_dt_add_memory_arch(u64 base, u64 size) 50 { 51 int in_use = 0; 52 53 if (!low_mem_sz) { 54 BUG_ON(base != low_mem_start); 55 low_mem_sz = size; 56 in_use = 1; 57 } else { 58 #ifdef CONFIG_HIGHMEM 59 high_mem_start = base; 60 high_mem_sz = size; 61 in_use = 1; 62 #endif 63 } 64 65 pr_info("Memory @ %llx [%lldM] %s\n", 66 base, TO_MB(size), !in_use ? "Not used":""); 67 } 68 69 #ifdef CONFIG_BLK_DEV_INITRD 70 static int __init early_initrd(char *p) 71 { 72 unsigned long start, size; 73 char *endp; 74 75 start = memparse(p, &endp); 76 if (*endp == ',') { 77 size = memparse(endp + 1, NULL); 78 79 initrd_start = (unsigned long)__va(start); 80 initrd_end = (unsigned long)__va(start + size); 81 } 82 return 0; 83 } 84 early_param("initrd", early_initrd); 85 #endif 86 87 /* 88 * First memory setup routine called from setup_arch() 89 * 1. setup swapper's mm @init_mm 90 * 2. Count the pages we have and setup bootmem allocator 91 * 3. zone setup 92 */ 93 void __init setup_arch_memory(void) 94 { 95 unsigned long zones_size[MAX_NR_ZONES]; 96 unsigned long zones_holes[MAX_NR_ZONES]; 97 98 init_mm.start_code = (unsigned long)_text; 99 init_mm.end_code = (unsigned long)_etext; 100 init_mm.end_data = (unsigned long)_edata; 101 init_mm.brk = (unsigned long)_end; 102 103 /* first page of system - kernel .vector starts here */ 104 min_low_pfn = ARCH_PFN_OFFSET; 105 106 /* Last usable page of low mem */ 107 max_low_pfn = max_pfn = PFN_DOWN(low_mem_start + low_mem_sz); 108 109 #ifdef CONFIG_HIGHMEM 110 min_high_pfn = PFN_DOWN(high_mem_start); 111 max_pfn = PFN_DOWN(high_mem_start + high_mem_sz); 112 #endif 113 114 max_mapnr = max_pfn - min_low_pfn; 115 116 /*------------- bootmem allocator setup -----------------------*/ 117 118 /* 119 * seed the bootmem allocator after any DT memory node parsing or 120 * "mem=xxx" cmdline overrides have potentially updated @arc_mem_sz 121 * 122 * Only low mem is added, otherwise we have crashes when allocating 123 * mem_map[] itself. NO_BOOTMEM allocates mem_map[] at the end of 124 * avail memory, ending in highmem with a > 32-bit address. However 125 * it then tries to memset it with a truncaed 32-bit handle, causing 126 * the crash 127 */ 128 129 memblock_add(low_mem_start, low_mem_sz); 130 memblock_reserve(low_mem_start, __pa(_end) - low_mem_start); 131 132 #ifdef CONFIG_BLK_DEV_INITRD 133 if (initrd_start) 134 memblock_reserve(__pa(initrd_start), initrd_end - initrd_start); 135 #endif 136 137 memblock_dump_all(); 138 139 /*----------------- node/zones setup --------------------------*/ 140 memset(zones_size, 0, sizeof(zones_size)); 141 memset(zones_holes, 0, sizeof(zones_holes)); 142 143 zones_size[ZONE_NORMAL] = max_low_pfn - min_low_pfn; 144 zones_holes[ZONE_NORMAL] = 0; 145 146 #ifdef CONFIG_HIGHMEM 147 zones_size[ZONE_HIGHMEM] = max_pfn - max_low_pfn; 148 149 /* This handles the peripheral address space hole */ 150 zones_holes[ZONE_HIGHMEM] = min_high_pfn - max_low_pfn; 151 #endif 152 153 /* 154 * We can't use the helper free_area_init(zones[]) because it uses 155 * PAGE_OFFSET to compute the @min_low_pfn which would be wrong 156 * when our kernel doesn't start at PAGE_OFFSET, i.e. 157 * PAGE_OFFSET != CONFIG_LINUX_LINK_BASE 158 */ 159 free_area_init_node(0, /* node-id */ 160 zones_size, /* num pages per zone */ 161 min_low_pfn, /* first pfn of node */ 162 zones_holes); /* holes */ 163 164 #ifdef CONFIG_HIGHMEM 165 high_memory = (void *)(min_high_pfn << PAGE_SHIFT); 166 kmap_init(); 167 #endif 168 } 169 170 /* 171 * mem_init - initializes memory 172 * 173 * Frees up bootmem 174 * Calculates and displays memory available/used 175 */ 176 void __init mem_init(void) 177 { 178 #ifdef CONFIG_HIGHMEM 179 unsigned long tmp; 180 181 reset_all_zones_managed_pages(); 182 for (tmp = min_high_pfn; tmp < max_pfn; tmp++) 183 free_highmem_page(pfn_to_page(tmp)); 184 #endif 185 186 free_all_bootmem(); 187 mem_init_print_info(NULL); 188 } 189 190 /* 191 * free_initmem: Free all the __init memory. 192 */ 193 void __init_refok free_initmem(void) 194 { 195 free_initmem_default(-1); 196 } 197 198 #ifdef CONFIG_BLK_DEV_INITRD 199 void __init free_initrd_mem(unsigned long start, unsigned long end) 200 { 201 free_reserved_area((void *)start, (void *)end, -1, "initrd"); 202 } 203 #endif 204