1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) 4 */ 5 6 #include <linux/kernel.h> 7 #include <linux/mm.h> 8 #include <linux/memblock.h> 9 #ifdef CONFIG_BLK_DEV_INITRD 10 #include <linux/initrd.h> 11 #endif 12 #include <linux/of_fdt.h> 13 #include <linux/swap.h> 14 #include <linux/module.h> 15 #include <linux/highmem.h> 16 #include <asm/page.h> 17 #include <asm/pgalloc.h> 18 #include <asm/sections.h> 19 #include <asm/arcregs.h> 20 21 pgd_t swapper_pg_dir[PTRS_PER_PGD] __aligned(PAGE_SIZE); 22 char empty_zero_page[PAGE_SIZE] __aligned(PAGE_SIZE); 23 EXPORT_SYMBOL(empty_zero_page); 24 25 static const unsigned long low_mem_start = CONFIG_LINUX_RAM_BASE; 26 static unsigned long low_mem_sz; 27 28 #ifdef CONFIG_HIGHMEM 29 static unsigned long min_high_pfn, max_high_pfn; 30 static u64 high_mem_start; 31 static u64 high_mem_sz; 32 #endif 33 34 #ifdef CONFIG_DISCONTIGMEM 35 struct pglist_data node_data[MAX_NUMNODES] __read_mostly; 36 EXPORT_SYMBOL(node_data); 37 #endif 38 39 long __init arc_get_mem_sz(void) 40 { 41 return low_mem_sz; 42 } 43 44 /* User can over-ride above with "mem=nnn[KkMm]" in cmdline */ 45 static int __init setup_mem_sz(char *str) 46 { 47 low_mem_sz = memparse(str, NULL) & PAGE_MASK; 48 49 /* early console might not be setup yet - it will show up later */ 50 pr_info("\"mem=%s\": mem sz set to %ldM\n", str, TO_MB(low_mem_sz)); 51 52 return 0; 53 } 54 early_param("mem", setup_mem_sz); 55 56 void __init early_init_dt_add_memory_arch(u64 base, u64 size) 57 { 58 int in_use = 0; 59 60 if (!low_mem_sz) { 61 if (base != low_mem_start) 62 panic("CONFIG_LINUX_RAM_BASE != DT memory { }"); 63 64 low_mem_sz = size; 65 in_use = 1; 66 } else { 67 #ifdef CONFIG_HIGHMEM 68 high_mem_start = base; 69 high_mem_sz = size; 70 in_use = 1; 71 #endif 72 } 73 74 pr_info("Memory @ %llx [%lldM] %s\n", 75 base, TO_MB(size), !in_use ? "Not used":""); 76 } 77 78 /* 79 * First memory setup routine called from setup_arch() 80 * 1. setup swapper's mm @init_mm 81 * 2. Count the pages we have and setup bootmem allocator 82 * 3. zone setup 83 */ 84 void __init setup_arch_memory(void) 85 { 86 unsigned long zones_size[MAX_NR_ZONES]; 87 unsigned long zones_holes[MAX_NR_ZONES]; 88 89 init_mm.start_code = (unsigned long)_text; 90 init_mm.end_code = (unsigned long)_etext; 91 init_mm.end_data = (unsigned long)_edata; 92 init_mm.brk = (unsigned long)_end; 93 94 /* first page of system - kernel .vector starts here */ 95 min_low_pfn = ARCH_PFN_OFFSET; 96 97 /* Last usable page of low mem */ 98 max_low_pfn = max_pfn = PFN_DOWN(low_mem_start + low_mem_sz); 99 100 #ifdef CONFIG_FLATMEM 101 /* pfn_valid() uses this */ 102 max_mapnr = max_low_pfn - min_low_pfn; 103 #endif 104 105 /*------------- bootmem allocator setup -----------------------*/ 106 107 /* 108 * seed the bootmem allocator after any DT memory node parsing or 109 * "mem=xxx" cmdline overrides have potentially updated @arc_mem_sz 110 * 111 * Only low mem is added, otherwise we have crashes when allocating 112 * mem_map[] itself. NO_BOOTMEM allocates mem_map[] at the end of 113 * avail memory, ending in highmem with a > 32-bit address. However 114 * it then tries to memset it with a truncaed 32-bit handle, causing 115 * the crash 116 */ 117 118 memblock_add_node(low_mem_start, low_mem_sz, 0); 119 memblock_reserve(CONFIG_LINUX_LINK_BASE, 120 __pa(_end) - CONFIG_LINUX_LINK_BASE); 121 122 #ifdef CONFIG_BLK_DEV_INITRD 123 if (phys_initrd_size) { 124 memblock_reserve(phys_initrd_start, phys_initrd_size); 125 initrd_start = (unsigned long)__va(phys_initrd_start); 126 initrd_end = initrd_start + phys_initrd_size; 127 } 128 #endif 129 130 early_init_fdt_reserve_self(); 131 early_init_fdt_scan_reserved_mem(); 132 133 memblock_dump_all(); 134 135 /*----------------- node/zones setup --------------------------*/ 136 memset(zones_size, 0, sizeof(zones_size)); 137 memset(zones_holes, 0, sizeof(zones_holes)); 138 139 zones_size[ZONE_NORMAL] = max_low_pfn - min_low_pfn; 140 zones_holes[ZONE_NORMAL] = 0; 141 142 /* 143 * We can't use the helper free_area_init(zones[]) because it uses 144 * PAGE_OFFSET to compute the @min_low_pfn which would be wrong 145 * when our kernel doesn't start at PAGE_OFFSET, i.e. 146 * PAGE_OFFSET != CONFIG_LINUX_RAM_BASE 147 */ 148 free_area_init_node(0, /* node-id */ 149 zones_size, /* num pages per zone */ 150 min_low_pfn, /* first pfn of node */ 151 zones_holes); /* holes */ 152 153 #ifdef CONFIG_HIGHMEM 154 /* 155 * Populate a new node with highmem 156 * 157 * On ARC (w/o PAE) HIGHMEM addresses are actually smaller (0 based) 158 * than addresses in normal ala low memory (0x8000_0000 based). 159 * Even with PAE, the huge peripheral space hole would waste a lot of 160 * mem with single mem_map[]. This warrants a mem_map per region design. 161 * Thus HIGHMEM on ARC is imlemented with DISCONTIGMEM. 162 * 163 * DISCONTIGMEM in turns requires multiple nodes. node 0 above is 164 * populated with normal memory zone while node 1 only has highmem 165 */ 166 node_set_online(1); 167 168 min_high_pfn = PFN_DOWN(high_mem_start); 169 max_high_pfn = PFN_DOWN(high_mem_start + high_mem_sz); 170 171 zones_size[ZONE_NORMAL] = 0; 172 zones_holes[ZONE_NORMAL] = 0; 173 174 zones_size[ZONE_HIGHMEM] = max_high_pfn - min_high_pfn; 175 zones_holes[ZONE_HIGHMEM] = 0; 176 177 free_area_init_node(1, /* node-id */ 178 zones_size, /* num pages per zone */ 179 min_high_pfn, /* first pfn of node */ 180 zones_holes); /* holes */ 181 182 high_memory = (void *)(min_high_pfn << PAGE_SHIFT); 183 kmap_init(); 184 #endif 185 } 186 187 /* 188 * mem_init - initializes memory 189 * 190 * Frees up bootmem 191 * Calculates and displays memory available/used 192 */ 193 void __init mem_init(void) 194 { 195 #ifdef CONFIG_HIGHMEM 196 unsigned long tmp; 197 198 reset_all_zones_managed_pages(); 199 for (tmp = min_high_pfn; tmp < max_high_pfn; tmp++) 200 free_highmem_page(pfn_to_page(tmp)); 201 #endif 202 203 memblock_free_all(); 204 mem_init_print_info(NULL); 205 } 206