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; 34 static u64 high_mem_start; 35 static u64 high_mem_sz; 36 #endif 37 38 /* User can over-ride above with "mem=nnn[KkMm]" in cmdline */ 39 static int __init setup_mem_sz(char *str) 40 { 41 low_mem_sz = memparse(str, NULL) & PAGE_MASK; 42 43 /* early console might not be setup yet - it will show up later */ 44 pr_info("\"mem=%s\": mem sz set to %ldM\n", str, TO_MB(low_mem_sz)); 45 46 return 0; 47 } 48 early_param("mem", setup_mem_sz); 49 50 void __init early_init_dt_add_memory_arch(u64 base, u64 size) 51 { 52 int in_use = 0; 53 54 if (!low_mem_sz) { 55 if (base != low_mem_start) 56 panic("CONFIG_LINUX_LINK_BASE != DT memory { }"); 57 58 low_mem_sz = size; 59 in_use = 1; 60 } else { 61 #ifdef CONFIG_HIGHMEM 62 high_mem_start = base; 63 high_mem_sz = size; 64 in_use = 1; 65 #endif 66 } 67 68 pr_info("Memory @ %llx [%lldM] %s\n", 69 base, TO_MB(size), !in_use ? "Not used":""); 70 } 71 72 #ifdef CONFIG_BLK_DEV_INITRD 73 static int __init early_initrd(char *p) 74 { 75 unsigned long start, size; 76 char *endp; 77 78 start = memparse(p, &endp); 79 if (*endp == ',') { 80 size = memparse(endp + 1, NULL); 81 82 initrd_start = (unsigned long)__va(start); 83 initrd_end = (unsigned long)__va(start + size); 84 } 85 return 0; 86 } 87 early_param("initrd", early_initrd); 88 #endif 89 90 /* 91 * First memory setup routine called from setup_arch() 92 * 1. setup swapper's mm @init_mm 93 * 2. Count the pages we have and setup bootmem allocator 94 * 3. zone setup 95 */ 96 void __init setup_arch_memory(void) 97 { 98 unsigned long zones_size[MAX_NR_ZONES]; 99 unsigned long zones_holes[MAX_NR_ZONES]; 100 101 init_mm.start_code = (unsigned long)_text; 102 init_mm.end_code = (unsigned long)_etext; 103 init_mm.end_data = (unsigned long)_edata; 104 init_mm.brk = (unsigned long)_end; 105 106 /* first page of system - kernel .vector starts here */ 107 min_low_pfn = ARCH_PFN_OFFSET; 108 109 /* Last usable page of low mem */ 110 max_low_pfn = max_pfn = PFN_DOWN(low_mem_start + low_mem_sz); 111 112 #ifdef CONFIG_HIGHMEM 113 min_high_pfn = PFN_DOWN(high_mem_start); 114 max_pfn = PFN_DOWN(high_mem_start + high_mem_sz); 115 #endif 116 117 max_mapnr = max_pfn - min_low_pfn; 118 119 /*------------- bootmem allocator setup -----------------------*/ 120 121 /* 122 * seed the bootmem allocator after any DT memory node parsing or 123 * "mem=xxx" cmdline overrides have potentially updated @arc_mem_sz 124 * 125 * Only low mem is added, otherwise we have crashes when allocating 126 * mem_map[] itself. NO_BOOTMEM allocates mem_map[] at the end of 127 * avail memory, ending in highmem with a > 32-bit address. However 128 * it then tries to memset it with a truncaed 32-bit handle, causing 129 * the crash 130 */ 131 132 memblock_add(low_mem_start, low_mem_sz); 133 memblock_reserve(low_mem_start, __pa(_end) - low_mem_start); 134 135 #ifdef CONFIG_BLK_DEV_INITRD 136 if (initrd_start) 137 memblock_reserve(__pa(initrd_start), initrd_end - initrd_start); 138 #endif 139 140 early_init_fdt_reserve_self(); 141 early_init_fdt_scan_reserved_mem(); 142 143 memblock_dump_all(); 144 145 /*----------------- node/zones setup --------------------------*/ 146 memset(zones_size, 0, sizeof(zones_size)); 147 memset(zones_holes, 0, sizeof(zones_holes)); 148 149 zones_size[ZONE_NORMAL] = max_low_pfn - min_low_pfn; 150 zones_holes[ZONE_NORMAL] = 0; 151 152 #ifdef CONFIG_HIGHMEM 153 zones_size[ZONE_HIGHMEM] = max_pfn - max_low_pfn; 154 155 /* This handles the peripheral address space hole */ 156 zones_holes[ZONE_HIGHMEM] = min_high_pfn - max_low_pfn; 157 #endif 158 159 /* 160 * We can't use the helper free_area_init(zones[]) because it uses 161 * PAGE_OFFSET to compute the @min_low_pfn which would be wrong 162 * when our kernel doesn't start at PAGE_OFFSET, i.e. 163 * PAGE_OFFSET != CONFIG_LINUX_LINK_BASE 164 */ 165 free_area_init_node(0, /* node-id */ 166 zones_size, /* num pages per zone */ 167 min_low_pfn, /* first pfn of node */ 168 zones_holes); /* holes */ 169 170 #ifdef CONFIG_HIGHMEM 171 high_memory = (void *)(min_high_pfn << PAGE_SHIFT); 172 kmap_init(); 173 #endif 174 } 175 176 /* 177 * mem_init - initializes memory 178 * 179 * Frees up bootmem 180 * Calculates and displays memory available/used 181 */ 182 void __init mem_init(void) 183 { 184 #ifdef CONFIG_HIGHMEM 185 unsigned long tmp; 186 187 reset_all_zones_managed_pages(); 188 for (tmp = min_high_pfn; tmp < max_pfn; tmp++) 189 free_highmem_page(pfn_to_page(tmp)); 190 #endif 191 192 free_all_bootmem(); 193 mem_init_print_info(NULL); 194 } 195 196 /* 197 * free_initmem: Free all the __init memory. 198 */ 199 void __init_refok free_initmem(void) 200 { 201 free_initmem_default(-1); 202 } 203 204 #ifdef CONFIG_BLK_DEV_INITRD 205 void __init free_initrd_mem(unsigned long start, unsigned long end) 206 { 207 free_reserved_area((void *)start, (void *)end, -1, "initrd"); 208 } 209 #endif 210