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 #include <linux/swap.h> 14 #include <linux/module.h> 15 #include <asm/page.h> 16 #include <asm/pgalloc.h> 17 #include <asm/sections.h> 18 #include <asm/arcregs.h> 19 20 pgd_t swapper_pg_dir[PTRS_PER_PGD] __aligned(PAGE_SIZE); 21 char empty_zero_page[PAGE_SIZE] __aligned(PAGE_SIZE); 22 EXPORT_SYMBOL(empty_zero_page); 23 24 /* Default tot mem from .config */ 25 static unsigned long arc_mem_sz = 0x20000000; /* some default */ 26 27 /* User can over-ride above with "mem=nnn[KkMm]" in cmdline */ 28 static int __init setup_mem_sz(char *str) 29 { 30 arc_mem_sz = memparse(str, NULL) & PAGE_MASK; 31 32 /* early console might not be setup yet - it will show up later */ 33 pr_info("\"mem=%s\": mem sz set to %ldM\n", str, TO_MB(arc_mem_sz)); 34 35 return 0; 36 } 37 early_param("mem", setup_mem_sz); 38 39 void __init early_init_dt_add_memory_arch(u64 base, u64 size) 40 { 41 arc_mem_sz = size & PAGE_MASK; 42 pr_info("Memory size set via devicetree %ldM\n", TO_MB(arc_mem_sz)); 43 } 44 45 /* 46 * First memory setup routine called from setup_arch() 47 * 1. setup swapper's mm @init_mm 48 * 2. Count the pages we have and setup bootmem allocator 49 * 3. zone setup 50 */ 51 void __init setup_arch_memory(void) 52 { 53 unsigned long zones_size[MAX_NR_ZONES] = { 0, 0 }; 54 unsigned long end_mem = CONFIG_LINUX_LINK_BASE + arc_mem_sz; 55 56 init_mm.start_code = (unsigned long)_text; 57 init_mm.end_code = (unsigned long)_etext; 58 init_mm.end_data = (unsigned long)_edata; 59 init_mm.brk = (unsigned long)_end; 60 61 /* 62 * We do it here, so that memory is correctly instantiated 63 * even if "mem=xxx" cmline over-ride is given and/or 64 * DT has memory node. Each causes an update to @arc_mem_sz 65 * and we finally add memory one here 66 */ 67 memblock_add(CONFIG_LINUX_LINK_BASE, arc_mem_sz); 68 69 /*------------- externs in mm need setting up ---------------*/ 70 71 /* first page of system - kernel .vector starts here */ 72 min_low_pfn = PFN_DOWN(CONFIG_LINUX_LINK_BASE); 73 74 /* Last usable page of low mem (no HIGHMEM yet for ARC port) */ 75 max_low_pfn = max_pfn = PFN_DOWN(end_mem); 76 77 max_mapnr = max_low_pfn - min_low_pfn; 78 79 /*------------- reserve kernel image -----------------------*/ 80 memblock_reserve(CONFIG_LINUX_LINK_BASE, 81 __pa(_end) - CONFIG_LINUX_LINK_BASE); 82 83 memblock_dump_all(); 84 85 /*-------------- node setup --------------------------------*/ 86 memset(zones_size, 0, sizeof(zones_size)); 87 zones_size[ZONE_NORMAL] = max_low_pfn - min_low_pfn; 88 89 /* 90 * We can't use the helper free_area_init(zones[]) because it uses 91 * PAGE_OFFSET to compute the @min_low_pfn which would be wrong 92 * when our kernel doesn't start at PAGE_OFFSET, i.e. 93 * PAGE_OFFSET != CONFIG_LINUX_LINK_BASE 94 */ 95 free_area_init_node(0, /* node-id */ 96 zones_size, /* num pages per zone */ 97 min_low_pfn, /* first pfn of node */ 98 NULL); /* NO holes */ 99 } 100 101 /* 102 * mem_init - initializes memory 103 * 104 * Frees up bootmem 105 * Calculates and displays memory available/used 106 */ 107 void __init mem_init(void) 108 { 109 high_memory = (void *)(CONFIG_LINUX_LINK_BASE + arc_mem_sz); 110 free_all_bootmem(); 111 mem_init_print_info(NULL); 112 } 113 114 /* 115 * free_initmem: Free all the __init memory. 116 */ 117 void __init_refok free_initmem(void) 118 { 119 free_initmem_default(-1); 120 } 121 122 #ifdef CONFIG_BLK_DEV_INITRD 123 void __init free_initrd_mem(unsigned long start, unsigned long end) 124 { 125 free_reserved_area((void *)start, (void *)end, -1, "initrd"); 126 } 127 #endif 128 129 #ifdef CONFIG_OF_FLATTREE 130 void __init early_init_dt_setup_initrd_arch(unsigned long start, 131 unsigned long end) 132 { 133 pr_err("%s(%lx, %lx)\n", __func__, start, end); 134 } 135 #endif /* CONFIG_OF_FLATTREE */ 136