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 unsigned long arch_pfn_offset; 32 EXPORT_SYMBOL(arch_pfn_offset); 33 #endif 34 35 #ifdef CONFIG_DISCONTIGMEM 36 struct pglist_data node_data[MAX_NUMNODES] __read_mostly; 37 EXPORT_SYMBOL(node_data); 38 #endif 39 40 long __init arc_get_mem_sz(void) 41 { 42 return low_mem_sz; 43 } 44 45 /* User can over-ride above with "mem=nnn[KkMm]" in cmdline */ 46 static int __init setup_mem_sz(char *str) 47 { 48 low_mem_sz = memparse(str, NULL) & PAGE_MASK; 49 50 /* early console might not be setup yet - it will show up later */ 51 pr_info("\"mem=%s\": mem sz set to %ldM\n", str, TO_MB(low_mem_sz)); 52 53 return 0; 54 } 55 early_param("mem", setup_mem_sz); 56 57 void __init early_init_dt_add_memory_arch(u64 base, u64 size) 58 { 59 int in_use = 0; 60 61 if (!low_mem_sz) { 62 if (base != low_mem_start) 63 panic("CONFIG_LINUX_RAM_BASE != DT memory { }"); 64 65 low_mem_sz = size; 66 in_use = 1; 67 memblock_add_node(base, size, 0); 68 } else { 69 #ifdef CONFIG_HIGHMEM 70 high_mem_start = base; 71 high_mem_sz = size; 72 in_use = 1; 73 memblock_add_node(base, size, 1); 74 memblock_reserve(base, size); 75 #endif 76 } 77 78 pr_info("Memory @ %llx [%lldM] %s\n", 79 base, TO_MB(size), !in_use ? "Not used":""); 80 } 81 82 bool arch_has_descending_max_zone_pfns(void) 83 { 84 return !IS_ENABLED(CONFIG_ARC_HAS_PAE40); 85 } 86 87 /* 88 * First memory setup routine called from setup_arch() 89 * 1. setup swapper's mm @init_mm 90 * 2. Count the pages we have and setup bootmem allocator 91 * 3. zone setup 92 */ 93 void __init setup_arch_memory(void) 94 { 95 unsigned long max_zone_pfn[MAX_NR_ZONES] = { 0 }; 96 97 init_mm.start_code = (unsigned long)_text; 98 init_mm.end_code = (unsigned long)_etext; 99 init_mm.end_data = (unsigned long)_edata; 100 init_mm.brk = (unsigned long)_end; 101 102 /* first page of system - kernel .vector starts here */ 103 min_low_pfn = virt_to_pfn(CONFIG_LINUX_RAM_BASE); 104 105 /* Last usable page of low mem */ 106 max_low_pfn = max_pfn = PFN_DOWN(low_mem_start + low_mem_sz); 107 108 /*------------- bootmem allocator setup -----------------------*/ 109 110 /* 111 * seed the bootmem allocator after any DT memory node parsing or 112 * "mem=xxx" cmdline overrides have potentially updated @arc_mem_sz 113 * 114 * Only low mem is added, otherwise we have crashes when allocating 115 * mem_map[] itself. NO_BOOTMEM allocates mem_map[] at the end of 116 * avail memory, ending in highmem with a > 32-bit address. However 117 * it then tries to memset it with a truncaed 32-bit handle, causing 118 * the crash 119 */ 120 121 memblock_reserve(CONFIG_LINUX_LINK_BASE, 122 __pa(_end) - CONFIG_LINUX_LINK_BASE); 123 124 #ifdef CONFIG_BLK_DEV_INITRD 125 if (phys_initrd_size) { 126 memblock_reserve(phys_initrd_start, phys_initrd_size); 127 initrd_start = (unsigned long)__va(phys_initrd_start); 128 initrd_end = initrd_start + phys_initrd_size; 129 } 130 #endif 131 132 early_init_fdt_reserve_self(); 133 early_init_fdt_scan_reserved_mem(); 134 135 memblock_dump_all(); 136 137 /*----------------- node/zones setup --------------------------*/ 138 max_zone_pfn[ZONE_NORMAL] = max_low_pfn; 139 140 #ifdef CONFIG_HIGHMEM 141 /* 142 * Populate a new node with highmem 143 * 144 * On ARC (w/o PAE) HIGHMEM addresses are actually smaller (0 based) 145 * than addresses in normal ala low memory (0x8000_0000 based). 146 * Even with PAE, the huge peripheral space hole would waste a lot of 147 * mem with single mem_map[]. This warrants a mem_map per region design. 148 * Thus HIGHMEM on ARC is imlemented with DISCONTIGMEM. 149 * 150 * DISCONTIGMEM in turns requires multiple nodes. node 0 above is 151 * populated with normal memory zone while node 1 only has highmem 152 */ 153 #ifdef CONFIG_DISCONTIGMEM 154 node_set_online(1); 155 #endif 156 157 min_high_pfn = PFN_DOWN(high_mem_start); 158 max_high_pfn = PFN_DOWN(high_mem_start + high_mem_sz); 159 160 max_zone_pfn[ZONE_HIGHMEM] = min_low_pfn; 161 162 high_memory = (void *)(min_high_pfn << PAGE_SHIFT); 163 164 arch_pfn_offset = min(min_low_pfn, min_high_pfn); 165 kmap_init(); 166 167 #else /* CONFIG_HIGHMEM */ 168 /* pfn_valid() uses this when FLATMEM=y and HIGHMEM=n */ 169 max_mapnr = max_low_pfn - min_low_pfn; 170 171 #endif /* CONFIG_HIGHMEM */ 172 173 free_area_init(max_zone_pfn); 174 } 175 176 static void __init highmem_init(void) 177 { 178 #ifdef CONFIG_HIGHMEM 179 unsigned long tmp; 180 181 memblock_free(high_mem_start, high_mem_sz); 182 for (tmp = min_high_pfn; tmp < max_high_pfn; tmp++) 183 free_highmem_page(pfn_to_page(tmp)); 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 memblock_free_all(); 196 highmem_init(); 197 mem_init_print_info(NULL); 198 } 199 200 #ifdef CONFIG_HIGHMEM 201 int pfn_valid(unsigned long pfn) 202 { 203 return (pfn >= min_high_pfn && pfn <= max_high_pfn) || 204 (pfn >= min_low_pfn && pfn <= max_low_pfn); 205 } 206 EXPORT_SYMBOL(pfn_valid); 207 #endif 208