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