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, MEMBLOCK_NONE); 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, MEMBLOCK_NONE); 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 /* 78 * First memory setup routine called from setup_arch() 79 * 1. setup swapper's mm @init_mm 80 * 2. Count the pages we have and setup bootmem allocator 81 * 3. zone setup 82 */ 83 void __init setup_arch_memory(void) 84 { 85 unsigned long max_zone_pfn[MAX_NR_ZONES] = { 0 }; 86 87 setup_initial_init_mm(_text, _etext, _edata, _end); 88 89 /* first page of system - kernel .vector starts here */ 90 min_low_pfn = virt_to_pfn((void *)CONFIG_LINUX_RAM_BASE); 91 92 /* Last usable page of low mem */ 93 max_low_pfn = max_pfn = PFN_DOWN(low_mem_start + low_mem_sz); 94 95 /*------------- bootmem allocator setup -----------------------*/ 96 97 /* 98 * seed the bootmem allocator after any DT memory node parsing or 99 * "mem=xxx" cmdline overrides have potentially updated @arc_mem_sz 100 * 101 * Only low mem is added, otherwise we have crashes when allocating 102 * mem_map[] itself. NO_BOOTMEM allocates mem_map[] at the end of 103 * avail memory, ending in highmem with a > 32-bit address. However 104 * it then tries to memset it with a truncaed 32-bit handle, causing 105 * the crash 106 */ 107 108 memblock_reserve(CONFIG_LINUX_LINK_BASE, 109 __pa(_end) - CONFIG_LINUX_LINK_BASE); 110 111 #ifdef CONFIG_BLK_DEV_INITRD 112 if (phys_initrd_size) { 113 memblock_reserve(phys_initrd_start, phys_initrd_size); 114 initrd_start = (unsigned long)__va(phys_initrd_start); 115 initrd_end = initrd_start + phys_initrd_size; 116 } 117 #endif 118 119 early_init_fdt_reserve_self(); 120 early_init_fdt_scan_reserved_mem(); 121 122 memblock_dump_all(); 123 124 /*----------------- node/zones setup --------------------------*/ 125 max_zone_pfn[ZONE_NORMAL] = max_low_pfn; 126 127 #ifdef CONFIG_HIGHMEM 128 /* 129 * On ARC (w/o PAE) HIGHMEM addresses are actually smaller (0 based) 130 * than addresses in normal aka low memory (0x8000_0000 based). 131 * Even with PAE, the huge peripheral space hole would waste a lot of 132 * mem with single contiguous mem_map[]. 133 * Thus when HIGHMEM on ARC is enabled the memory map corresponding 134 * to the hole is freed and ARC specific version of pfn_valid() 135 * handles the hole in the memory map. 136 */ 137 138 min_high_pfn = PFN_DOWN(high_mem_start); 139 max_high_pfn = PFN_DOWN(high_mem_start + high_mem_sz); 140 141 /* 142 * max_high_pfn should be ok here for both HIGHMEM and HIGHMEM+PAE. 143 * For HIGHMEM without PAE max_high_pfn should be less than 144 * min_low_pfn to guarantee that these two regions don't overlap. 145 * For PAE case highmem is greater than lowmem, so it is natural 146 * to use max_high_pfn. 147 * 148 * In both cases, holes should be handled by pfn_valid(). 149 */ 150 max_zone_pfn[ZONE_HIGHMEM] = max_high_pfn; 151 152 high_memory = (void *)(min_high_pfn << PAGE_SHIFT); 153 154 arch_pfn_offset = min(min_low_pfn, min_high_pfn); 155 kmap_init(); 156 157 #else /* CONFIG_HIGHMEM */ 158 /* pfn_valid() uses this when FLATMEM=y and HIGHMEM=n */ 159 max_mapnr = max_low_pfn - min_low_pfn; 160 161 #endif /* CONFIG_HIGHMEM */ 162 163 free_area_init(max_zone_pfn); 164 } 165 166 static void __init highmem_init(void) 167 { 168 #ifdef CONFIG_HIGHMEM 169 unsigned long tmp; 170 171 memblock_phys_free(high_mem_start, high_mem_sz); 172 for (tmp = min_high_pfn; tmp < max_high_pfn; tmp++) 173 free_highmem_page(pfn_to_page(tmp)); 174 #endif 175 } 176 177 /* 178 * mem_init - initializes memory 179 * 180 * Frees up bootmem 181 * Calculates and displays memory available/used 182 */ 183 void __init mem_init(void) 184 { 185 memblock_free_all(); 186 highmem_init(); 187 188 BUILD_BUG_ON((PTRS_PER_PGD * sizeof(pgd_t)) > PAGE_SIZE); 189 BUILD_BUG_ON((PTRS_PER_PUD * sizeof(pud_t)) > PAGE_SIZE); 190 BUILD_BUG_ON((PTRS_PER_PMD * sizeof(pmd_t)) > PAGE_SIZE); 191 BUILD_BUG_ON((PTRS_PER_PTE * sizeof(pte_t)) > PAGE_SIZE); 192 } 193 194 #ifdef CONFIG_HIGHMEM 195 int pfn_valid(unsigned long pfn) 196 { 197 return (pfn >= min_high_pfn && pfn <= max_high_pfn) || 198 (pfn >= min_low_pfn && pfn <= max_low_pfn); 199 } 200 EXPORT_SYMBOL(pfn_valid); 201 #endif 202