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 long __init arc_get_mem_sz(void) 36 { 37 return low_mem_sz; 38 } 39 40 /* User can over-ride above with "mem=nnn[KkMm]" in cmdline */ 41 static int __init setup_mem_sz(char *str) 42 { 43 low_mem_sz = memparse(str, NULL) & PAGE_MASK; 44 45 /* early console might not be setup yet - it will show up later */ 46 pr_info("\"mem=%s\": mem sz set to %ldM\n", str, TO_MB(low_mem_sz)); 47 48 return 0; 49 } 50 early_param("mem", setup_mem_sz); 51 52 void __init early_init_dt_add_memory_arch(u64 base, u64 size) 53 { 54 int in_use = 0; 55 56 if (!low_mem_sz) { 57 if (base != low_mem_start) 58 panic("CONFIG_LINUX_RAM_BASE != DT memory { }"); 59 60 low_mem_sz = size; 61 in_use = 1; 62 memblock_add_node(base, size, 0); 63 } else { 64 #ifdef CONFIG_HIGHMEM 65 high_mem_start = base; 66 high_mem_sz = size; 67 in_use = 1; 68 memblock_add_node(base, size, 1); 69 memblock_reserve(base, size); 70 #endif 71 } 72 73 pr_info("Memory @ %llx [%lldM] %s\n", 74 base, TO_MB(size), !in_use ? "Not used":""); 75 } 76 77 bool arch_has_descending_max_zone_pfns(void) 78 { 79 return !IS_ENABLED(CONFIG_ARC_HAS_PAE40); 80 } 81 82 /* 83 * First memory setup routine called from setup_arch() 84 * 1. setup swapper's mm @init_mm 85 * 2. Count the pages we have and setup bootmem allocator 86 * 3. zone setup 87 */ 88 void __init setup_arch_memory(void) 89 { 90 unsigned long max_zone_pfn[MAX_NR_ZONES] = { 0 }; 91 92 init_mm.start_code = (unsigned long)_text; 93 init_mm.end_code = (unsigned long)_etext; 94 init_mm.end_data = (unsigned long)_edata; 95 init_mm.brk = (unsigned long)_end; 96 97 /* first page of system - kernel .vector starts here */ 98 min_low_pfn = virt_to_pfn(CONFIG_LINUX_RAM_BASE); 99 100 /* Last usable page of low mem */ 101 max_low_pfn = max_pfn = PFN_DOWN(low_mem_start + low_mem_sz); 102 103 /*------------- bootmem allocator setup -----------------------*/ 104 105 /* 106 * seed the bootmem allocator after any DT memory node parsing or 107 * "mem=xxx" cmdline overrides have potentially updated @arc_mem_sz 108 * 109 * Only low mem is added, otherwise we have crashes when allocating 110 * mem_map[] itself. NO_BOOTMEM allocates mem_map[] at the end of 111 * avail memory, ending in highmem with a > 32-bit address. However 112 * it then tries to memset it with a truncaed 32-bit handle, causing 113 * the crash 114 */ 115 116 memblock_reserve(CONFIG_LINUX_LINK_BASE, 117 __pa(_end) - CONFIG_LINUX_LINK_BASE); 118 119 #ifdef CONFIG_BLK_DEV_INITRD 120 if (phys_initrd_size) { 121 memblock_reserve(phys_initrd_start, phys_initrd_size); 122 initrd_start = (unsigned long)__va(phys_initrd_start); 123 initrd_end = initrd_start + phys_initrd_size; 124 } 125 #endif 126 127 early_init_fdt_reserve_self(); 128 early_init_fdt_scan_reserved_mem(); 129 130 memblock_dump_all(); 131 132 /*----------------- node/zones setup --------------------------*/ 133 max_zone_pfn[ZONE_NORMAL] = max_low_pfn; 134 135 #ifdef CONFIG_HIGHMEM 136 /* 137 * On ARC (w/o PAE) HIGHMEM addresses are actually smaller (0 based) 138 * than addresses in normal aka low memory (0x8000_0000 based). 139 * Even with PAE, the huge peripheral space hole would waste a lot of 140 * mem with single contiguous mem_map[]. 141 * Thus when HIGHMEM on ARC is enabled the memory map corresponding 142 * to the hole is freed and ARC specific version of pfn_valid() 143 * handles the hole in the memory map. 144 */ 145 146 min_high_pfn = PFN_DOWN(high_mem_start); 147 max_high_pfn = PFN_DOWN(high_mem_start + high_mem_sz); 148 149 /* 150 * max_high_pfn should be ok here for both HIGHMEM and HIGHMEM+PAE. 151 * For HIGHMEM without PAE max_high_pfn should be less than 152 * min_low_pfn to guarantee that these two regions don't overlap. 153 * For PAE case highmem is greater than lowmem, so it is natural 154 * to use max_high_pfn. 155 * 156 * In both cases, holes should be handled by pfn_valid(). 157 */ 158 max_zone_pfn[ZONE_HIGHMEM] = max_high_pfn; 159 160 high_memory = (void *)(min_high_pfn << PAGE_SHIFT); 161 162 arch_pfn_offset = min(min_low_pfn, min_high_pfn); 163 kmap_init(); 164 165 #else /* CONFIG_HIGHMEM */ 166 /* pfn_valid() uses this when FLATMEM=y and HIGHMEM=n */ 167 max_mapnr = max_low_pfn - min_low_pfn; 168 169 #endif /* CONFIG_HIGHMEM */ 170 171 free_area_init(max_zone_pfn); 172 } 173 174 static void __init highmem_init(void) 175 { 176 #ifdef CONFIG_HIGHMEM 177 unsigned long tmp; 178 179 memblock_free(high_mem_start, high_mem_sz); 180 for (tmp = min_high_pfn; tmp < max_high_pfn; tmp++) 181 free_highmem_page(pfn_to_page(tmp)); 182 #endif 183 } 184 185 /* 186 * mem_init - initializes memory 187 * 188 * Frees up bootmem 189 * Calculates and displays memory available/used 190 */ 191 void __init mem_init(void) 192 { 193 memblock_free_all(); 194 highmem_init(); 195 } 196 197 #ifdef CONFIG_HIGHMEM 198 int pfn_valid(unsigned long pfn) 199 { 200 return (pfn >= min_high_pfn && pfn <= max_high_pfn) || 201 (pfn >= min_low_pfn && pfn <= max_low_pfn); 202 } 203 EXPORT_SYMBOL(pfn_valid); 204 #endif 205