1 /* 2 * arch/xtensa/mm/init.c 3 * 4 * Derived from MIPS, PPC. 5 * 6 * This file is subject to the terms and conditions of the GNU General Public 7 * License. See the file "COPYING" in the main directory of this archive 8 * for more details. 9 * 10 * Copyright (C) 2001 - 2005 Tensilica Inc. 11 * 12 * Chris Zankel <chris@zankel.net> 13 * Joe Taylor <joe@tensilica.com, joetylr@yahoo.com> 14 * Marc Gauthier 15 * Kevin Chea 16 */ 17 18 #include <linux/kernel.h> 19 #include <linux/errno.h> 20 #include <linux/bootmem.h> 21 #include <linux/swap.h> 22 #include <linux/mman.h> 23 #include <linux/nodemask.h> 24 #include <linux/mm.h> 25 #include <linux/slab.h> 26 27 #include <asm/pgtable.h> 28 #include <asm/bootparam.h> 29 #include <asm/mmu_context.h> 30 #include <asm/tlb.h> 31 #include <asm/page.h> 32 #include <asm/pgalloc.h> 33 34 35 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers); 36 37 /* References to section boundaries */ 38 39 extern char _ftext, _etext, _fdata, _edata, _rodata_end; 40 extern char __init_begin, __init_end; 41 42 /* 43 * mem_reserve(start, end, must_exist) 44 * 45 * Reserve some memory from the memory pool. 46 * 47 * Parameters: 48 * start Start of region, 49 * end End of region, 50 * must_exist Must exist in memory pool. 51 * 52 * Returns: 53 * 0 (memory area couldn't be mapped) 54 * -1 (success) 55 */ 56 57 int __init mem_reserve(unsigned long start, unsigned long end, int must_exist) 58 { 59 int i; 60 61 if (start == end) 62 return 0; 63 64 start = start & PAGE_MASK; 65 end = PAGE_ALIGN(end); 66 67 for (i = 0; i < sysmem.nr_banks; i++) 68 if (start < sysmem.bank[i].end 69 && end >= sysmem.bank[i].start) 70 break; 71 72 if (i == sysmem.nr_banks) { 73 if (must_exist) 74 printk (KERN_WARNING "mem_reserve: [0x%0lx, 0x%0lx) " 75 "not in any region!\n", start, end); 76 return 0; 77 } 78 79 if (start > sysmem.bank[i].start) { 80 if (end < sysmem.bank[i].end) { 81 /* split entry */ 82 if (sysmem.nr_banks >= SYSMEM_BANKS_MAX) 83 panic("meminfo overflow\n"); 84 sysmem.bank[sysmem.nr_banks].start = end; 85 sysmem.bank[sysmem.nr_banks].end = sysmem.bank[i].end; 86 sysmem.nr_banks++; 87 } 88 sysmem.bank[i].end = start; 89 } else { 90 if (end < sysmem.bank[i].end) 91 sysmem.bank[i].start = end; 92 else { 93 /* remove entry */ 94 sysmem.nr_banks--; 95 sysmem.bank[i].start = sysmem.bank[sysmem.nr_banks].start; 96 sysmem.bank[i].end = sysmem.bank[sysmem.nr_banks].end; 97 } 98 } 99 return -1; 100 } 101 102 103 /* 104 * Initialize the bootmem system and give it all the memory we have available. 105 */ 106 107 void __init bootmem_init(void) 108 { 109 unsigned long pfn; 110 unsigned long bootmap_start, bootmap_size; 111 int i; 112 113 max_low_pfn = max_pfn = 0; 114 min_low_pfn = ~0; 115 116 for (i=0; i < sysmem.nr_banks; i++) { 117 pfn = PAGE_ALIGN(sysmem.bank[i].start) >> PAGE_SHIFT; 118 if (pfn < min_low_pfn) 119 min_low_pfn = pfn; 120 pfn = PAGE_ALIGN(sysmem.bank[i].end - 1) >> PAGE_SHIFT; 121 if (pfn > max_pfn) 122 max_pfn = pfn; 123 } 124 125 if (min_low_pfn > max_pfn) 126 panic("No memory found!\n"); 127 128 max_low_pfn = max_pfn < MAX_MEM_PFN >> PAGE_SHIFT ? 129 max_pfn : MAX_MEM_PFN >> PAGE_SHIFT; 130 131 /* Find an area to use for the bootmem bitmap. */ 132 133 bootmap_size = bootmem_bootmap_pages(max_low_pfn) << PAGE_SHIFT; 134 bootmap_start = ~0; 135 136 for (i=0; i<sysmem.nr_banks; i++) 137 if (sysmem.bank[i].end - sysmem.bank[i].start >= bootmap_size) { 138 bootmap_start = sysmem.bank[i].start; 139 break; 140 } 141 142 if (bootmap_start == ~0UL) 143 panic("Cannot find %ld bytes for bootmap\n", bootmap_size); 144 145 /* Reserve the bootmem bitmap area */ 146 147 mem_reserve(bootmap_start, bootmap_start + bootmap_size, 1); 148 bootmap_size = init_bootmem_node(NODE_DATA(0), 149 bootmap_start >> PAGE_SHIFT, 150 min_low_pfn, 151 max_low_pfn); 152 153 /* Add all remaining memory pieces into the bootmem map */ 154 155 for (i=0; i<sysmem.nr_banks; i++) 156 free_bootmem(sysmem.bank[i].start, 157 sysmem.bank[i].end - sysmem.bank[i].start); 158 159 } 160 161 162 void __init paging_init(void) 163 { 164 unsigned long zones_size[MAX_NR_ZONES]; 165 int i; 166 167 /* All pages are DMA-able, so we put them all in the DMA zone. */ 168 169 zones_size[ZONE_DMA] = max_low_pfn; 170 for (i = 1; i < MAX_NR_ZONES; i++) 171 zones_size[i] = 0; 172 173 #ifdef CONFIG_HIGHMEM 174 zones_size[ZONE_HIGHMEM] = max_pfn - max_low_pfn; 175 #endif 176 177 /* Initialize the kernel's page tables. */ 178 179 memset(swapper_pg_dir, 0, PAGE_SIZE); 180 181 free_area_init(zones_size); 182 } 183 184 /* 185 * Flush the mmu and reset associated register to default values. 186 */ 187 188 void __init init_mmu (void) 189 { 190 /* Writing zeros to the <t>TLBCFG special registers ensure 191 * that valid values exist in the register. For existing 192 * PGSZID<w> fields, zero selects the first element of the 193 * page-size array. For nonexistent PGSZID<w> fields, zero is 194 * the best value to write. Also, when changing PGSZID<w> 195 * fields, the corresponding TLB must be flushed. 196 */ 197 set_itlbcfg_register (0); 198 set_dtlbcfg_register (0); 199 flush_tlb_all (); 200 201 /* Set rasid register to a known value. */ 202 203 set_rasid_register (ASID_USER_FIRST); 204 205 /* Set PTEVADDR special register to the start of the page 206 * table, which is in kernel mappable space (ie. not 207 * statically mapped). This register's value is undefined on 208 * reset. 209 */ 210 set_ptevaddr_register (PGTABLE_START); 211 } 212 213 /* 214 * Initialize memory pages. 215 */ 216 217 void __init mem_init(void) 218 { 219 unsigned long codesize, reservedpages, datasize, initsize; 220 unsigned long highmemsize, tmp, ram; 221 222 max_mapnr = num_physpages = max_low_pfn; 223 high_memory = (void *) __va(max_mapnr << PAGE_SHIFT); 224 highmemsize = 0; 225 226 #ifdef CONFIG_HIGHMEM 227 #error HIGHGMEM not implemented in init.c 228 #endif 229 230 totalram_pages += free_all_bootmem(); 231 232 reservedpages = ram = 0; 233 for (tmp = 0; tmp < max_low_pfn; tmp++) { 234 ram++; 235 if (PageReserved(mem_map+tmp)) 236 reservedpages++; 237 } 238 239 codesize = (unsigned long) &_etext - (unsigned long) &_ftext; 240 datasize = (unsigned long) &_edata - (unsigned long) &_fdata; 241 initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin; 242 243 printk("Memory: %luk/%luk available (%ldk kernel code, %ldk reserved, " 244 "%ldk data, %ldk init %ldk highmem)\n", 245 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10), 246 ram << (PAGE_SHIFT-10), 247 codesize >> 10, 248 reservedpages << (PAGE_SHIFT-10), 249 datasize >> 10, 250 initsize >> 10, 251 highmemsize >> 10); 252 } 253 254 void 255 free_reserved_mem(void *start, void *end) 256 { 257 for (; start < end; start += PAGE_SIZE) { 258 ClearPageReserved(virt_to_page(start)); 259 init_page_count(virt_to_page(start)); 260 free_page((unsigned long)start); 261 totalram_pages++; 262 } 263 } 264 265 #ifdef CONFIG_BLK_DEV_INITRD 266 extern int initrd_is_mapped; 267 268 void free_initrd_mem(unsigned long start, unsigned long end) 269 { 270 if (initrd_is_mapped) { 271 free_reserved_mem((void*)start, (void*)end); 272 printk ("Freeing initrd memory: %ldk freed\n",(end-start)>>10); 273 } 274 } 275 #endif 276 277 void free_initmem(void) 278 { 279 free_reserved_mem(&__init_begin, &__init_end); 280 printk("Freeing unused kernel memory: %dk freed\n", 281 (&__init_end - &__init_begin) >> 10); 282 } 283 284 struct kmem_cache *pgtable_cache __read_mostly; 285 286 static void pgd_ctor(void* addr) 287 { 288 pte_t* ptep = (pte_t*)addr; 289 int i; 290 291 for (i = 0; i < 1024; i++, ptep++) 292 pte_clear(NULL, 0, ptep); 293 294 } 295 296 void __init pgtable_cache_init(void) 297 { 298 pgtable_cache = kmem_cache_create("pgd", 299 PAGE_SIZE, PAGE_SIZE, 300 SLAB_HWCACHE_ALIGN, 301 pgd_ctor); 302 } 303