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/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 static const unsigned long low_mem_start = CONFIG_LINUX_RAM_BASE; 25 static unsigned long low_mem_sz; 26 27 #ifdef CONFIG_HIGHMEM 28 static unsigned long min_high_pfn, max_high_pfn; 29 static phys_addr_t high_mem_start; 30 static phys_addr_t high_mem_sz; 31 #endif 32 33 #ifdef CONFIG_DISCONTIGMEM 34 struct pglist_data node_data[MAX_NUMNODES] __read_mostly; 35 EXPORT_SYMBOL(node_data); 36 #endif 37 38 long __init arc_get_mem_sz(void) 39 { 40 return low_mem_sz; 41 } 42 43 /* User can over-ride above with "mem=nnn[KkMm]" in cmdline */ 44 static int __init setup_mem_sz(char *str) 45 { 46 low_mem_sz = memparse(str, NULL) & PAGE_MASK; 47 48 /* early console might not be setup yet - it will show up later */ 49 pr_info("\"mem=%s\": mem sz set to %ldM\n", str, TO_MB(low_mem_sz)); 50 51 return 0; 52 } 53 early_param("mem", setup_mem_sz); 54 55 void __init early_init_dt_add_memory_arch(u64 base, u64 size) 56 { 57 int in_use = 0; 58 59 if (!low_mem_sz) { 60 if (base != low_mem_start) 61 panic("CONFIG_LINUX_RAM_BASE != DT memory { }"); 62 63 low_mem_sz = size; 64 in_use = 1; 65 memblock_add_node(base, size, 0); 66 } else { 67 #ifdef CONFIG_HIGHMEM 68 high_mem_start = base; 69 high_mem_sz = size; 70 in_use = 1; 71 memblock_add_node(base, size, 1); 72 memblock_reserve(base, size); 73 #endif 74 } 75 76 pr_info("Memory @ %llx [%lldM] %s\n", 77 base, TO_MB(size), !in_use ? "Not used":""); 78 } 79 80 bool arch_has_descending_max_zone_pfns(void) 81 { 82 return !IS_ENABLED(CONFIG_ARC_HAS_PAE40); 83 } 84 85 /* 86 * First memory setup routine called from setup_arch() 87 * 1. setup swapper's mm @init_mm 88 * 2. Count the pages we have and setup bootmem allocator 89 * 3. zone setup 90 */ 91 void __init setup_arch_memory(void) 92 { 93 unsigned long max_zone_pfn[MAX_NR_ZONES] = { 0 }; 94 95 init_mm.start_code = (unsigned long)_text; 96 init_mm.end_code = (unsigned long)_etext; 97 init_mm.end_data = (unsigned long)_edata; 98 init_mm.brk = (unsigned long)_end; 99 100 /* first page of system - kernel .vector starts here */ 101 min_low_pfn = ARCH_PFN_OFFSET; 102 103 /* Last usable page of low mem */ 104 max_low_pfn = max_pfn = PFN_DOWN(low_mem_start + low_mem_sz); 105 106 #ifdef CONFIG_FLATMEM 107 /* pfn_valid() uses this */ 108 max_mapnr = max_low_pfn - min_low_pfn; 109 #endif 110 111 /*------------- bootmem allocator setup -----------------------*/ 112 113 /* 114 * seed the bootmem allocator after any DT memory node parsing or 115 * "mem=xxx" cmdline overrides have potentially updated @arc_mem_sz 116 * 117 * Only low mem is added, otherwise we have crashes when allocating 118 * mem_map[] itself. NO_BOOTMEM allocates mem_map[] at the end of 119 * avail memory, ending in highmem with a > 32-bit address. However 120 * it then tries to memset it with a truncaed 32-bit handle, causing 121 * the crash 122 */ 123 124 memblock_reserve(CONFIG_LINUX_LINK_BASE, 125 __pa(_end) - CONFIG_LINUX_LINK_BASE); 126 127 #ifdef CONFIG_BLK_DEV_INITRD 128 if (phys_initrd_size) { 129 memblock_reserve(phys_initrd_start, phys_initrd_size); 130 initrd_start = (unsigned long)__va(phys_initrd_start); 131 initrd_end = initrd_start + phys_initrd_size; 132 } 133 #endif 134 135 early_init_fdt_reserve_self(); 136 early_init_fdt_scan_reserved_mem(); 137 138 memblock_dump_all(); 139 140 /*----------------- node/zones setup --------------------------*/ 141 max_zone_pfn[ZONE_NORMAL] = max_low_pfn; 142 143 #ifdef CONFIG_HIGHMEM 144 /* 145 * Populate a new node with highmem 146 * 147 * On ARC (w/o PAE) HIGHMEM addresses are actually smaller (0 based) 148 * than addresses in normal ala low memory (0x8000_0000 based). 149 * Even with PAE, the huge peripheral space hole would waste a lot of 150 * mem with single mem_map[]. This warrants a mem_map per region design. 151 * Thus HIGHMEM on ARC is imlemented with DISCONTIGMEM. 152 * 153 * DISCONTIGMEM in turns requires multiple nodes. node 0 above is 154 * populated with normal memory zone while node 1 only has highmem 155 */ 156 node_set_online(1); 157 158 min_high_pfn = PFN_DOWN(high_mem_start); 159 max_high_pfn = PFN_DOWN(high_mem_start + high_mem_sz); 160 161 max_zone_pfn[ZONE_HIGHMEM] = min_low_pfn; 162 163 high_memory = (void *)(min_high_pfn << PAGE_SHIFT); 164 kmap_init(); 165 #endif 166 167 free_area_init(max_zone_pfn); 168 } 169 170 static void __init highmem_init(void) 171 { 172 #ifdef CONFIG_HIGHMEM 173 unsigned long tmp; 174 175 memblock_free(high_mem_start, high_mem_sz); 176 for (tmp = min_high_pfn; tmp < max_high_pfn; tmp++) 177 free_highmem_page(pfn_to_page(tmp)); 178 #endif 179 } 180 181 /* 182 * mem_init - initializes memory 183 * 184 * Frees up bootmem 185 * Calculates and displays memory available/used 186 */ 187 void __init mem_init(void) 188 { 189 memblock_free_all(); 190 highmem_init(); 191 mem_init_print_info(NULL); 192 } 193