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), min_low_pfn, 149 bootmap_start >> PAGE_SHIFT, 150 max_low_pfn); 151 152 /* Add all remaining memory pieces into the bootmem map */ 153 154 for (i=0; i<sysmem.nr_banks; i++) 155 free_bootmem(sysmem.bank[i].start, 156 sysmem.bank[i].end - sysmem.bank[i].start); 157 158 } 159 160 161 void __init paging_init(void) 162 { 163 unsigned long zones_size[MAX_NR_ZONES]; 164 int i; 165 166 /* All pages are DMA-able, so we put them all in the DMA zone. */ 167 168 zones_size[ZONE_DMA] = max_low_pfn; 169 for (i = 1; i < MAX_NR_ZONES; i++) 170 zones_size[i] = 0; 171 172 #ifdef CONFIG_HIGHMEM 173 zones_size[ZONE_HIGHMEM] = max_pfn - max_low_pfn; 174 #endif 175 176 /* Initialize the kernel's page tables. */ 177 178 memset(swapper_pg_dir, 0, PAGE_SIZE); 179 180 free_area_init(zones_size); 181 } 182 183 /* 184 * Flush the mmu and reset associated register to default values. 185 */ 186 187 void __init init_mmu (void) 188 { 189 /* Writing zeros to the <t>TLBCFG special registers ensure 190 * that valid values exist in the register. For existing 191 * PGSZID<w> fields, zero selects the first element of the 192 * page-size array. For nonexistent PGSZID<w> fields, zero is 193 * the best value to write. Also, when changing PGSZID<w> 194 * fields, the corresponding TLB must be flushed. 195 */ 196 set_itlbcfg_register (0); 197 set_dtlbcfg_register (0); 198 flush_tlb_all (); 199 200 /* Set rasid register to a known value. */ 201 202 set_rasid_register (ASID_USER_FIRST); 203 204 /* Set PTEVADDR special register to the start of the page 205 * table, which is in kernel mappable space (ie. not 206 * statically mapped). This register's value is undefined on 207 * reset. 208 */ 209 set_ptevaddr_register (PGTABLE_START); 210 } 211 212 /* 213 * Initialize memory pages. 214 */ 215 216 void __init mem_init(void) 217 { 218 unsigned long codesize, reservedpages, datasize, initsize; 219 unsigned long highmemsize, tmp, ram; 220 221 max_mapnr = num_physpages = max_low_pfn; 222 high_memory = (void *) __va(max_mapnr << PAGE_SHIFT); 223 highmemsize = 0; 224 225 #ifdef CONFIG_HIGHMEM 226 #error HIGHGMEM not implemented in init.c 227 #endif 228 229 totalram_pages += free_all_bootmem(); 230 231 reservedpages = ram = 0; 232 for (tmp = 0; tmp < max_low_pfn; tmp++) { 233 ram++; 234 if (PageReserved(mem_map+tmp)) 235 reservedpages++; 236 } 237 238 codesize = (unsigned long) &_etext - (unsigned long) &_ftext; 239 datasize = (unsigned long) &_edata - (unsigned long) &_fdata; 240 initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin; 241 242 printk("Memory: %luk/%luk available (%ldk kernel code, %ldk reserved, " 243 "%ldk data, %ldk init %ldk highmem)\n", 244 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10), 245 ram << (PAGE_SHIFT-10), 246 codesize >> 10, 247 reservedpages << (PAGE_SHIFT-10), 248 datasize >> 10, 249 initsize >> 10, 250 highmemsize >> 10); 251 } 252 253 void 254 free_reserved_mem(void *start, void *end) 255 { 256 for (; start < end; start += PAGE_SIZE) { 257 ClearPageReserved(virt_to_page(start)); 258 init_page_count(virt_to_page(start)); 259 free_page((unsigned long)start); 260 totalram_pages++; 261 } 262 } 263 264 #ifdef CONFIG_BLK_DEV_INITRD 265 extern int initrd_is_mapped; 266 267 void free_initrd_mem(unsigned long start, unsigned long end) 268 { 269 if (initrd_is_mapped) { 270 free_reserved_mem((void*)start, (void*)end); 271 printk ("Freeing initrd memory: %ldk freed\n",(end-start)>>10); 272 } 273 } 274 #endif 275 276 void free_initmem(void) 277 { 278 free_reserved_mem(&__init_begin, &__init_end); 279 printk("Freeing unused kernel memory: %dk freed\n", 280 (&__init_end - &__init_begin) >> 10); 281 } 282 283 void show_mem(void) 284 { 285 int i, free = 0, total = 0, reserved = 0; 286 int shared = 0, cached = 0; 287 288 printk("Mem-info:\n"); 289 show_free_areas(); 290 printk("Free swap: %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10)); 291 i = max_mapnr; 292 while (i-- > 0) { 293 total++; 294 if (PageReserved(mem_map+i)) 295 reserved++; 296 else if (PageSwapCache(mem_map+i)) 297 cached++; 298 else if (!page_count(mem_map + i)) 299 free++; 300 else 301 shared += page_count(mem_map + i) - 1; 302 } 303 printk("%d pages of RAM\n", total); 304 printk("%d reserved pages\n", reserved); 305 printk("%d pages shared\n", shared); 306 printk("%d pages swap cached\n",cached); 307 printk("%d free pages\n", free); 308 } 309 310 struct kmem_cache *pgtable_cache __read_mostly; 311 312 static void pgd_ctor(void* addr) 313 { 314 pte_t* ptep = (pte_t*)addr; 315 int i; 316 317 for (i = 0; i < 1024; i++, ptep++) 318 pte_clear(NULL, 0, ptep); 319 320 } 321 322 void __init pgtable_cache_init(void) 323 { 324 pgtable_cache = kmem_cache_create("pgd", 325 PAGE_SIZE, PAGE_SIZE, 326 SLAB_HWCACHE_ALIGN, 327 pgd_ctor); 328 } 329