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 setup_initial_init_mm(_text, _etext, _edata, _end); 93 94 /* first page of system - kernel .vector starts here */ 95 min_low_pfn = virt_to_pfn(CONFIG_LINUX_RAM_BASE); 96 97 /* Last usable page of low mem */ 98 max_low_pfn = max_pfn = PFN_DOWN(low_mem_start + low_mem_sz); 99 100 /*------------- bootmem allocator setup -----------------------*/ 101 102 /* 103 * seed the bootmem allocator after any DT memory node parsing or 104 * "mem=xxx" cmdline overrides have potentially updated @arc_mem_sz 105 * 106 * Only low mem is added, otherwise we have crashes when allocating 107 * mem_map[] itself. NO_BOOTMEM allocates mem_map[] at the end of 108 * avail memory, ending in highmem with a > 32-bit address. However 109 * it then tries to memset it with a truncaed 32-bit handle, causing 110 * the crash 111 */ 112 113 memblock_reserve(CONFIG_LINUX_LINK_BASE, 114 __pa(_end) - CONFIG_LINUX_LINK_BASE); 115 116 #ifdef CONFIG_BLK_DEV_INITRD 117 if (phys_initrd_size) { 118 memblock_reserve(phys_initrd_start, phys_initrd_size); 119 initrd_start = (unsigned long)__va(phys_initrd_start); 120 initrd_end = initrd_start + phys_initrd_size; 121 } 122 #endif 123 124 early_init_fdt_reserve_self(); 125 early_init_fdt_scan_reserved_mem(); 126 127 memblock_dump_all(); 128 129 /*----------------- node/zones setup --------------------------*/ 130 max_zone_pfn[ZONE_NORMAL] = max_low_pfn; 131 132 #ifdef CONFIG_HIGHMEM 133 /* 134 * On ARC (w/o PAE) HIGHMEM addresses are actually smaller (0 based) 135 * than addresses in normal aka low memory (0x8000_0000 based). 136 * Even with PAE, the huge peripheral space hole would waste a lot of 137 * mem with single contiguous mem_map[]. 138 * Thus when HIGHMEM on ARC is enabled the memory map corresponding 139 * to the hole is freed and ARC specific version of pfn_valid() 140 * handles the hole in the memory map. 141 */ 142 143 min_high_pfn = PFN_DOWN(high_mem_start); 144 max_high_pfn = PFN_DOWN(high_mem_start + high_mem_sz); 145 146 /* 147 * max_high_pfn should be ok here for both HIGHMEM and HIGHMEM+PAE. 148 * For HIGHMEM without PAE max_high_pfn should be less than 149 * min_low_pfn to guarantee that these two regions don't overlap. 150 * For PAE case highmem is greater than lowmem, so it is natural 151 * to use max_high_pfn. 152 * 153 * In both cases, holes should be handled by pfn_valid(). 154 */ 155 max_zone_pfn[ZONE_HIGHMEM] = max_high_pfn; 156 157 high_memory = (void *)(min_high_pfn << PAGE_SHIFT); 158 159 arch_pfn_offset = min(min_low_pfn, min_high_pfn); 160 kmap_init(); 161 162 #else /* CONFIG_HIGHMEM */ 163 /* pfn_valid() uses this when FLATMEM=y and HIGHMEM=n */ 164 max_mapnr = max_low_pfn - min_low_pfn; 165 166 #endif /* CONFIG_HIGHMEM */ 167 168 free_area_init(max_zone_pfn); 169 } 170 171 static void __init highmem_init(void) 172 { 173 #ifdef CONFIG_HIGHMEM 174 unsigned long tmp; 175 176 memblock_free(high_mem_start, high_mem_sz); 177 for (tmp = min_high_pfn; tmp < max_high_pfn; tmp++) 178 free_highmem_page(pfn_to_page(tmp)); 179 #endif 180 } 181 182 /* 183 * mem_init - initializes memory 184 * 185 * Frees up bootmem 186 * Calculates and displays memory available/used 187 */ 188 void __init mem_init(void) 189 { 190 memblock_free_all(); 191 highmem_init(); 192 193 BUILD_BUG_ON((PTRS_PER_PGD * sizeof(pgd_t)) > PAGE_SIZE); 194 BUILD_BUG_ON((PTRS_PER_PUD * sizeof(pud_t)) > PAGE_SIZE); 195 BUILD_BUG_ON((PTRS_PER_PMD * sizeof(pmd_t)) > PAGE_SIZE); 196 BUILD_BUG_ON((PTRS_PER_PTE * sizeof(pte_t)) > PAGE_SIZE); 197 } 198 199 #ifdef CONFIG_HIGHMEM 200 int pfn_valid(unsigned long pfn) 201 { 202 return (pfn >= min_high_pfn && pfn <= max_high_pfn) || 203 (pfn >= min_low_pfn && pfn <= max_low_pfn); 204 } 205 EXPORT_SYMBOL(pfn_valid); 206 #endif 207