1 /* 2 * Copyright (C) 2012 Regents of the University of California 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public License 6 * as published by the Free Software Foundation, version 2. 7 * 8 * This program is distributed in the hope that it will be useful, 9 * but WITHOUT ANY WARRANTY; without even the implied warranty of 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 11 * GNU General Public License for more details. 12 */ 13 14 #include <linux/init.h> 15 #include <linux/mm.h> 16 #include <linux/memblock.h> 17 #include <linux/initrd.h> 18 #include <linux/swap.h> 19 #include <linux/sizes.h> 20 #include <linux/of_fdt.h> 21 22 #include <asm/fixmap.h> 23 #include <asm/tlbflush.h> 24 #include <asm/sections.h> 25 #include <asm/pgtable.h> 26 #include <asm/io.h> 27 28 static void __init zone_sizes_init(void) 29 { 30 unsigned long max_zone_pfns[MAX_NR_ZONES] = { 0, }; 31 32 #ifdef CONFIG_ZONE_DMA32 33 max_zone_pfns[ZONE_DMA32] = PFN_DOWN(min(4UL * SZ_1G, 34 (unsigned long) PFN_PHYS(max_low_pfn))); 35 #endif 36 max_zone_pfns[ZONE_NORMAL] = max_low_pfn; 37 38 free_area_init_nodes(max_zone_pfns); 39 } 40 41 void setup_zero_page(void) 42 { 43 memset((void *)empty_zero_page, 0, PAGE_SIZE); 44 } 45 46 void __init paging_init(void) 47 { 48 setup_zero_page(); 49 local_flush_tlb_all(); 50 zone_sizes_init(); 51 } 52 53 void __init mem_init(void) 54 { 55 #ifdef CONFIG_FLATMEM 56 BUG_ON(!mem_map); 57 #endif /* CONFIG_FLATMEM */ 58 59 high_memory = (void *)(__va(PFN_PHYS(max_low_pfn))); 60 memblock_free_all(); 61 62 mem_init_print_info(NULL); 63 } 64 65 void free_initmem(void) 66 { 67 free_initmem_default(0); 68 } 69 70 #ifdef CONFIG_BLK_DEV_INITRD 71 static void __init setup_initrd(void) 72 { 73 unsigned long size; 74 75 if (initrd_start >= initrd_end) { 76 pr_info("initrd not found or empty"); 77 goto disable; 78 } 79 if (__pa(initrd_end) > PFN_PHYS(max_low_pfn)) { 80 pr_err("initrd extends beyond end of memory"); 81 goto disable; 82 } 83 84 size = initrd_end - initrd_start; 85 memblock_reserve(__pa(initrd_start), size); 86 initrd_below_start_ok = 1; 87 88 pr_info("Initial ramdisk at: 0x%p (%lu bytes)\n", 89 (void *)(initrd_start), size); 90 return; 91 disable: 92 pr_cont(" - disabling initrd\n"); 93 initrd_start = 0; 94 initrd_end = 0; 95 } 96 97 void __init free_initrd_mem(unsigned long start, unsigned long end) 98 { 99 free_reserved_area((void *)start, (void *)end, -1, "initrd"); 100 } 101 #endif /* CONFIG_BLK_DEV_INITRD */ 102 103 void __init setup_bootmem(void) 104 { 105 struct memblock_region *reg; 106 phys_addr_t mem_size = 0; 107 108 /* Find the memory region containing the kernel */ 109 for_each_memblock(memory, reg) { 110 phys_addr_t vmlinux_end = __pa(_end); 111 phys_addr_t end = reg->base + reg->size; 112 113 if (reg->base <= vmlinux_end && vmlinux_end <= end) { 114 /* 115 * Reserve from the start of the region to the end of 116 * the kernel 117 */ 118 memblock_reserve(reg->base, vmlinux_end - reg->base); 119 mem_size = min(reg->size, (phys_addr_t)-PAGE_OFFSET); 120 } 121 } 122 BUG_ON(mem_size == 0); 123 124 set_max_mapnr(PFN_DOWN(mem_size)); 125 max_low_pfn = PFN_DOWN(memblock_end_of_DRAM()); 126 127 #ifdef CONFIG_BLK_DEV_INITRD 128 setup_initrd(); 129 #endif /* CONFIG_BLK_DEV_INITRD */ 130 131 early_init_fdt_reserve_self(); 132 early_init_fdt_scan_reserved_mem(); 133 memblock_allow_resize(); 134 memblock_dump_all(); 135 136 for_each_memblock(memory, reg) { 137 unsigned long start_pfn = memblock_region_memory_base_pfn(reg); 138 unsigned long end_pfn = memblock_region_memory_end_pfn(reg); 139 140 memblock_set_node(PFN_PHYS(start_pfn), 141 PFN_PHYS(end_pfn - start_pfn), 142 &memblock.memory, 0); 143 } 144 } 145 146 pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss; 147 pgd_t trampoline_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE); 148 149 #ifndef __PAGETABLE_PMD_FOLDED 150 #define NUM_SWAPPER_PMDS ((uintptr_t)-PAGE_OFFSET >> PGDIR_SHIFT) 151 pmd_t swapper_pmd[PTRS_PER_PMD*((-PAGE_OFFSET)/PGDIR_SIZE)] __page_aligned_bss; 152 pmd_t trampoline_pmd[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE); 153 pmd_t fixmap_pmd[PTRS_PER_PMD] __page_aligned_bss; 154 #endif 155 156 pte_t fixmap_pte[PTRS_PER_PTE] __page_aligned_bss; 157 158 void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot) 159 { 160 unsigned long addr = __fix_to_virt(idx); 161 pte_t *ptep; 162 163 BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses); 164 165 ptep = &fixmap_pte[pte_index(addr)]; 166 167 if (pgprot_val(prot)) { 168 set_pte(ptep, pfn_pte(phys >> PAGE_SHIFT, prot)); 169 } else { 170 pte_clear(&init_mm, addr, ptep); 171 local_flush_tlb_page(addr); 172 } 173 } 174 175 asmlinkage void __init setup_vm(void) 176 { 177 extern char _start; 178 uintptr_t i; 179 uintptr_t pa = (uintptr_t) &_start; 180 pgprot_t prot = __pgprot(pgprot_val(PAGE_KERNEL) | _PAGE_EXEC); 181 182 va_pa_offset = PAGE_OFFSET - pa; 183 pfn_base = PFN_DOWN(pa); 184 185 /* Sanity check alignment and size */ 186 BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0); 187 BUG_ON((pa % (PAGE_SIZE * PTRS_PER_PTE)) != 0); 188 189 #ifndef __PAGETABLE_PMD_FOLDED 190 trampoline_pg_dir[(PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD] = 191 pfn_pgd(PFN_DOWN((uintptr_t)trampoline_pmd), 192 __pgprot(_PAGE_TABLE)); 193 trampoline_pmd[0] = pfn_pmd(PFN_DOWN(pa), prot); 194 195 for (i = 0; i < (-PAGE_OFFSET)/PGDIR_SIZE; ++i) { 196 size_t o = (PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD + i; 197 198 swapper_pg_dir[o] = 199 pfn_pgd(PFN_DOWN((uintptr_t)swapper_pmd) + i, 200 __pgprot(_PAGE_TABLE)); 201 } 202 for (i = 0; i < ARRAY_SIZE(swapper_pmd); i++) 203 swapper_pmd[i] = pfn_pmd(PFN_DOWN(pa + i * PMD_SIZE), prot); 204 205 swapper_pg_dir[(FIXADDR_START >> PGDIR_SHIFT) % PTRS_PER_PGD] = 206 pfn_pgd(PFN_DOWN((uintptr_t)fixmap_pmd), 207 __pgprot(_PAGE_TABLE)); 208 fixmap_pmd[(FIXADDR_START >> PMD_SHIFT) % PTRS_PER_PMD] = 209 pfn_pmd(PFN_DOWN((uintptr_t)fixmap_pte), 210 __pgprot(_PAGE_TABLE)); 211 #else 212 trampoline_pg_dir[(PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD] = 213 pfn_pgd(PFN_DOWN(pa), prot); 214 215 for (i = 0; i < (-PAGE_OFFSET)/PGDIR_SIZE; ++i) { 216 size_t o = (PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD + i; 217 218 swapper_pg_dir[o] = 219 pfn_pgd(PFN_DOWN(pa + i * PGDIR_SIZE), prot); 220 } 221 222 swapper_pg_dir[(FIXADDR_START >> PGDIR_SHIFT) % PTRS_PER_PGD] = 223 pfn_pgd(PFN_DOWN((uintptr_t)fixmap_pte), 224 __pgprot(_PAGE_TABLE)); 225 #endif 226 } 227