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_BLOCK_DEV_RAM 14 #include <linux/blk.h> 15 #endif 16 #include <linux/swap.h> 17 #include <linux/module.h> 18 #include <asm/page.h> 19 #include <asm/pgalloc.h> 20 #include <asm/sections.h> 21 #include <asm/arcregs.h> 22 23 pgd_t swapper_pg_dir[PTRS_PER_PGD] __aligned(PAGE_SIZE); 24 char empty_zero_page[PAGE_SIZE] __aligned(PAGE_SIZE); 25 EXPORT_SYMBOL(empty_zero_page); 26 27 /* Default tot mem from .config */ 28 static unsigned long arc_mem_sz = 0x20000000; /* some default */ 29 30 /* User can over-ride above with "mem=nnn[KkMm]" in cmdline */ 31 static int __init setup_mem_sz(char *str) 32 { 33 arc_mem_sz = memparse(str, NULL) & PAGE_MASK; 34 35 /* early console might not be setup yet - it will show up later */ 36 pr_info("\"mem=%s\": mem sz set to %ldM\n", str, TO_MB(arc_mem_sz)); 37 38 return 0; 39 } 40 early_param("mem", setup_mem_sz); 41 42 void __init early_init_dt_add_memory_arch(u64 base, u64 size) 43 { 44 arc_mem_sz = size & PAGE_MASK; 45 pr_info("Memory size set via devicetree %ldM\n", TO_MB(arc_mem_sz)); 46 } 47 48 /* 49 * First memory setup routine called from setup_arch() 50 * 1. setup swapper's mm @init_mm 51 * 2. Count the pages we have and setup bootmem allocator 52 * 3. zone setup 53 */ 54 void __init setup_arch_memory(void) 55 { 56 unsigned long zones_size[MAX_NR_ZONES] = { 0, 0 }; 57 unsigned long end_mem = CONFIG_LINUX_LINK_BASE + arc_mem_sz; 58 59 init_mm.start_code = (unsigned long)_text; 60 init_mm.end_code = (unsigned long)_etext; 61 init_mm.end_data = (unsigned long)_edata; 62 init_mm.brk = (unsigned long)_end; 63 64 /* 65 * We do it here, so that memory is correctly instantiated 66 * even if "mem=xxx" cmline over-ride is given and/or 67 * DT has memory node. Each causes an update to @arc_mem_sz 68 * and we finally add memory one here 69 */ 70 memblock_add(CONFIG_LINUX_LINK_BASE, arc_mem_sz); 71 72 /*------------- externs in mm need setting up ---------------*/ 73 74 /* first page of system - kernel .vector starts here */ 75 min_low_pfn = PFN_DOWN(CONFIG_LINUX_LINK_BASE); 76 77 /* Last usable page of low mem (no HIGHMEM yet for ARC port) */ 78 max_low_pfn = max_pfn = PFN_DOWN(end_mem); 79 80 max_mapnr = num_physpages = max_low_pfn - min_low_pfn; 81 82 /*------------- reserve kernel image -----------------------*/ 83 memblock_reserve(CONFIG_LINUX_LINK_BASE, 84 __pa(_end) - CONFIG_LINUX_LINK_BASE); 85 86 memblock_dump_all(); 87 88 /*-------------- node setup --------------------------------*/ 89 memset(zones_size, 0, sizeof(zones_size)); 90 zones_size[ZONE_NORMAL] = num_physpages; 91 92 /* 93 * We can't use the helper free_area_init(zones[]) because it uses 94 * PAGE_OFFSET to compute the @min_low_pfn which would be wrong 95 * when our kernel doesn't start at PAGE_OFFSET, i.e. 96 * PAGE_OFFSET != CONFIG_LINUX_LINK_BASE 97 */ 98 free_area_init_node(0, /* node-id */ 99 zones_size, /* num pages per zone */ 100 min_low_pfn, /* first pfn of node */ 101 NULL); /* NO holes */ 102 } 103 104 /* 105 * mem_init - initializes memory 106 * 107 * Frees up bootmem 108 * Calculates and displays memory available/used 109 */ 110 void __init mem_init(void) 111 { 112 int codesize, datasize, initsize, reserved_pages, free_pages; 113 int tmp; 114 115 high_memory = (void *)(CONFIG_LINUX_LINK_BASE + arc_mem_sz); 116 117 totalram_pages = free_all_bootmem(); 118 119 /* count all reserved pages [kernel code/data/mem_map..] */ 120 reserved_pages = 0; 121 for (tmp = 0; tmp < max_mapnr; tmp++) 122 if (PageReserved(mem_map + tmp)) 123 reserved_pages++; 124 125 /* XXX: nr_free_pages() is equivalent */ 126 free_pages = max_mapnr - reserved_pages; 127 128 /* 129 * For the purpose of display below, split the "reserve mem" 130 * kernel code/data is already shown explicitly, 131 * Show any other reservations (mem_map[ ] et al) 132 */ 133 reserved_pages -= (((unsigned int)_end - CONFIG_LINUX_LINK_BASE) >> 134 PAGE_SHIFT); 135 136 codesize = _etext - _text; 137 datasize = _end - _etext; 138 initsize = __init_end - __init_begin; 139 140 pr_info("Memory Available: %dM / %ldM (%dK code, %dK data, %dK init, %dK reserv)\n", 141 PAGES_TO_MB(free_pages), 142 TO_MB(arc_mem_sz), 143 TO_KB(codesize), TO_KB(datasize), TO_KB(initsize), 144 PAGES_TO_KB(reserved_pages)); 145 } 146 147 static void __init free_init_pages(const char *what, unsigned long begin, 148 unsigned long end) 149 { 150 unsigned long addr; 151 152 pr_info("Freeing %s: %ldk [%lx] to [%lx]\n", 153 what, TO_KB(end - begin), begin, end); 154 155 /* need to check that the page we free is not a partial page */ 156 for (addr = begin; addr + PAGE_SIZE <= end; addr += PAGE_SIZE) { 157 ClearPageReserved(virt_to_page(addr)); 158 init_page_count(virt_to_page(addr)); 159 free_page(addr); 160 totalram_pages++; 161 } 162 } 163 164 /* 165 * free_initmem: Free all the __init memory. 166 */ 167 void __init_refok free_initmem(void) 168 { 169 free_init_pages("unused kernel memory", 170 (unsigned long)__init_begin, 171 (unsigned long)__init_end); 172 } 173 174 #ifdef CONFIG_BLK_DEV_INITRD 175 void __init free_initrd_mem(unsigned long start, unsigned long end) 176 { 177 free_init_pages("initrd memory", start, end); 178 } 179 #endif 180 181 #ifdef CONFIG_OF_FLATTREE 182 void __init early_init_dt_setup_initrd_arch(unsigned long start, 183 unsigned long end) 184 { 185 pr_err("%s(%lx, %lx)\n", __func__, start, end); 186 } 187 #endif /* CONFIG_OF_FLATTREE */ 188