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 <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 #ifdef CONFIG_BLK_DEV_INITRD 49 static int __init early_initrd(char *p) 50 { 51 unsigned long start, size; 52 char *endp; 53 54 start = memparse(p, &endp); 55 if (*endp == ',') { 56 size = memparse(endp + 1, NULL); 57 58 initrd_start = (unsigned long)__va(start); 59 initrd_end = (unsigned long)__va(start + size); 60 } 61 return 0; 62 } 63 early_param("initrd", early_initrd); 64 #endif 65 66 /* 67 * First memory setup routine called from setup_arch() 68 * 1. setup swapper's mm @init_mm 69 * 2. Count the pages we have and setup bootmem allocator 70 * 3. zone setup 71 */ 72 void __init setup_arch_memory(void) 73 { 74 unsigned long zones_size[MAX_NR_ZONES] = { 0, 0 }; 75 unsigned long end_mem = CONFIG_LINUX_LINK_BASE + arc_mem_sz; 76 77 init_mm.start_code = (unsigned long)_text; 78 init_mm.end_code = (unsigned long)_etext; 79 init_mm.end_data = (unsigned long)_edata; 80 init_mm.brk = (unsigned long)_end; 81 82 /* 83 * We do it here, so that memory is correctly instantiated 84 * even if "mem=xxx" cmline over-ride is given and/or 85 * DT has memory node. Each causes an update to @arc_mem_sz 86 * and we finally add memory one here 87 */ 88 memblock_add(CONFIG_LINUX_LINK_BASE, arc_mem_sz); 89 90 /*------------- externs in mm need setting up ---------------*/ 91 92 /* first page of system - kernel .vector starts here */ 93 min_low_pfn = PFN_DOWN(CONFIG_LINUX_LINK_BASE); 94 95 /* Last usable page of low mem (no HIGHMEM yet for ARC port) */ 96 max_low_pfn = max_pfn = PFN_DOWN(end_mem); 97 98 max_mapnr = max_low_pfn - min_low_pfn; 99 100 /*------------- reserve kernel image -----------------------*/ 101 memblock_reserve(CONFIG_LINUX_LINK_BASE, 102 __pa(_end) - CONFIG_LINUX_LINK_BASE); 103 104 #ifdef CONFIG_BLK_DEV_INITRD 105 /*------------- reserve initrd image -----------------------*/ 106 if (initrd_start) 107 memblock_reserve(__pa(initrd_start), initrd_end - initrd_start); 108 #endif 109 110 memblock_dump_all(); 111 112 /*-------------- node setup --------------------------------*/ 113 memset(zones_size, 0, sizeof(zones_size)); 114 zones_size[ZONE_NORMAL] = max_low_pfn - min_low_pfn; 115 116 /* 117 * We can't use the helper free_area_init(zones[]) because it uses 118 * PAGE_OFFSET to compute the @min_low_pfn which would be wrong 119 * when our kernel doesn't start at PAGE_OFFSET, i.e. 120 * PAGE_OFFSET != CONFIG_LINUX_LINK_BASE 121 */ 122 free_area_init_node(0, /* node-id */ 123 zones_size, /* num pages per zone */ 124 min_low_pfn, /* first pfn of node */ 125 NULL); /* NO holes */ 126 } 127 128 /* 129 * mem_init - initializes memory 130 * 131 * Frees up bootmem 132 * Calculates and displays memory available/used 133 */ 134 void __init mem_init(void) 135 { 136 high_memory = (void *)(CONFIG_LINUX_LINK_BASE + arc_mem_sz); 137 free_all_bootmem(); 138 mem_init_print_info(NULL); 139 } 140 141 /* 142 * free_initmem: Free all the __init memory. 143 */ 144 void __init_refok free_initmem(void) 145 { 146 free_initmem_default(-1); 147 } 148 149 #ifdef CONFIG_BLK_DEV_INITRD 150 void __init free_initrd_mem(unsigned long start, unsigned long end) 151 { 152 free_reserved_area((void *)start, (void *)end, -1, "initrd"); 153 } 154 #endif 155