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/setup.h> 19 #include <asm/arcregs.h> 20 21 pgd_t swapper_pg_dir[PTRS_PER_PGD] __aligned(PAGE_SIZE); 22 char empty_zero_page[PAGE_SIZE] __aligned(PAGE_SIZE); 23 EXPORT_SYMBOL(empty_zero_page); 24 25 static const unsigned long low_mem_start = CONFIG_LINUX_RAM_BASE; 26 static unsigned long low_mem_sz; 27 28 #ifdef CONFIG_HIGHMEM 29 static unsigned long min_high_pfn, max_high_pfn; 30 static phys_addr_t high_mem_start; 31 static phys_addr_t high_mem_sz; 32 unsigned long arch_pfn_offset; 33 EXPORT_SYMBOL(arch_pfn_offset); 34 #endif 35 36 long __init arc_get_mem_sz(void) 37 { 38 return low_mem_sz; 39 } 40 41 /* User can over-ride above with "mem=nnn[KkMm]" in cmdline */ 42 static int __init setup_mem_sz(char *str) 43 { 44 low_mem_sz = memparse(str, NULL) & PAGE_MASK; 45 46 /* early console might not be setup yet - it will show up later */ 47 pr_info("\"mem=%s\": mem sz set to %ldM\n", str, TO_MB(low_mem_sz)); 48 49 return 0; 50 } 51 early_param("mem", setup_mem_sz); 52 53 void __init early_init_dt_add_memory_arch(u64 base, u64 size) 54 { 55 int in_use = 0; 56 57 if (!low_mem_sz) { 58 if (base != low_mem_start) 59 panic("CONFIG_LINUX_RAM_BASE != DT memory { }"); 60 61 low_mem_sz = size; 62 in_use = 1; 63 memblock_add_node(base, size, 0, MEMBLOCK_NONE); 64 } else { 65 #ifdef CONFIG_HIGHMEM 66 high_mem_start = base; 67 high_mem_sz = size; 68 in_use = 1; 69 memblock_add_node(base, size, 1, MEMBLOCK_NONE); 70 memblock_reserve(base, size); 71 #endif 72 } 73 74 pr_info("Memory @ %llx [%lldM] %s\n", 75 base, TO_MB(size), !in_use ? "Not used":""); 76 } 77 78 void __init arch_zone_limits_init(unsigned long *max_zone_pfn) 79 { 80 /*----------------- node/zones setup --------------------------*/ 81 max_zone_pfn[ZONE_NORMAL] = max_low_pfn; 82 83 #ifdef CONFIG_HIGHMEM 84 /* 85 * max_high_pfn should be ok here for both HIGHMEM and HIGHMEM+PAE. 86 * For HIGHMEM without PAE max_high_pfn should be less than 87 * min_low_pfn to guarantee that these two regions don't overlap. 88 * For PAE case highmem is greater than lowmem, so it is natural 89 * to use max_high_pfn. 90 * 91 * In both cases, holes should be handled by pfn_valid(). 92 */ 93 max_zone_pfn[ZONE_HIGHMEM] = max_high_pfn; 94 #endif 95 } 96 97 /* 98 * First memory setup routine called from setup_arch() 99 * 1. setup swapper's mm @init_mm 100 * 2. Count the pages we have and setup bootmem allocator 101 * 3. zone setup 102 */ 103 void __init setup_arch_memory(void) 104 { 105 setup_initial_init_mm(_text, _etext, _edata, _end); 106 107 /* first page of system - kernel .vector starts here */ 108 min_low_pfn = virt_to_pfn((void *)CONFIG_LINUX_RAM_BASE); 109 110 /* Last usable page of low mem */ 111 max_low_pfn = max_pfn = PFN_DOWN(low_mem_start + low_mem_sz); 112 113 /*------------- bootmem allocator setup -----------------------*/ 114 115 /* 116 * seed the bootmem allocator after any DT memory node parsing or 117 * "mem=xxx" cmdline overrides have potentially updated @arc_mem_sz 118 * 119 * Only low mem is added, otherwise we have crashes when allocating 120 * mem_map[] itself. NO_BOOTMEM allocates mem_map[] at the end of 121 * avail memory, ending in highmem with a > 32-bit address. However 122 * it then tries to memset it with a truncaed 32-bit handle, causing 123 * the crash 124 */ 125 126 memblock_reserve(CONFIG_LINUX_LINK_BASE, 127 __pa(_end) - CONFIG_LINUX_LINK_BASE); 128 129 #ifdef CONFIG_BLK_DEV_INITRD 130 if (phys_initrd_size) { 131 memblock_reserve(phys_initrd_start, phys_initrd_size); 132 initrd_start = (unsigned long)__va(phys_initrd_start); 133 initrd_end = initrd_start + phys_initrd_size; 134 } 135 #endif 136 137 early_init_fdt_reserve_self(); 138 early_init_fdt_scan_reserved_mem(); 139 140 memblock_dump_all(); 141 142 #ifdef CONFIG_HIGHMEM 143 /* 144 * On ARC (w/o PAE) HIGHMEM addresses are actually smaller (0 based) 145 * than addresses in normal aka low memory (0x8000_0000 based). 146 * Even with PAE, the huge peripheral space hole would waste a lot of 147 * mem with single contiguous mem_map[]. 148 * Thus when HIGHMEM on ARC is enabled the memory map corresponding 149 * to the hole is freed and ARC specific version of pfn_valid() 150 * handles the hole in the memory map. 151 */ 152 153 min_high_pfn = PFN_DOWN(high_mem_start); 154 max_high_pfn = PFN_DOWN(high_mem_start + high_mem_sz); 155 156 arch_pfn_offset = min(min_low_pfn, min_high_pfn); 157 kmap_init(); 158 #endif /* CONFIG_HIGHMEM */ 159 } 160 161 void __init arch_mm_preinit(void) 162 { 163 #ifdef CONFIG_HIGHMEM 164 memblock_phys_free(high_mem_start, high_mem_sz); 165 #endif 166 167 BUILD_BUG_ON((PTRS_PER_PGD * sizeof(pgd_t)) > PAGE_SIZE); 168 BUILD_BUG_ON((PTRS_PER_PUD * sizeof(pud_t)) > PAGE_SIZE); 169 BUILD_BUG_ON((PTRS_PER_PMD * sizeof(pmd_t)) > PAGE_SIZE); 170 BUILD_BUG_ON((PTRS_PER_PTE * sizeof(pte_t)) > PAGE_SIZE); 171 } 172 173 #ifdef CONFIG_HIGHMEM 174 int pfn_valid(unsigned long pfn) 175 { 176 return (pfn >= min_high_pfn && pfn <= max_high_pfn) || 177 (pfn >= min_low_pfn && pfn <= max_low_pfn); 178 } 179 EXPORT_SYMBOL(pfn_valid); 180 #endif 181