1 /* $Id: init.c,v 1.19 2004/02/21 04:42:16 kkojima Exp $ 2 * 3 * linux/arch/sh/mm/init.c 4 * 5 * Copyright (C) 1999 Niibe Yutaka 6 * Copyright (C) 2002, 2004 Paul Mundt 7 * 8 * Based on linux/arch/i386/mm/init.c: 9 * Copyright (C) 1995 Linus Torvalds 10 */ 11 12 #include <linux/signal.h> 13 #include <linux/sched.h> 14 #include <linux/kernel.h> 15 #include <linux/errno.h> 16 #include <linux/string.h> 17 #include <linux/types.h> 18 #include <linux/ptrace.h> 19 #include <linux/mman.h> 20 #include <linux/mm.h> 21 #include <linux/swap.h> 22 #include <linux/smp.h> 23 #include <linux/init.h> 24 #include <linux/highmem.h> 25 #include <linux/bootmem.h> 26 #include <linux/pagemap.h> 27 #include <linux/proc_fs.h> 28 #include <asm/processor.h> 29 #include <asm/system.h> 30 #include <asm/uaccess.h> 31 #include <asm/pgtable.h> 32 #include <asm/pgalloc.h> 33 #include <asm/mmu_context.h> 34 #include <asm/io.h> 35 #include <asm/tlb.h> 36 #include <asm/cacheflush.h> 37 #include <asm/cache.h> 38 39 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers); 40 pgd_t swapper_pg_dir[PTRS_PER_PGD]; 41 42 /* 43 * Cache of MMU context last used. 44 */ 45 unsigned long mmu_context_cache = NO_CONTEXT; 46 47 #ifdef CONFIG_MMU 48 /* It'd be good if these lines were in the standard header file. */ 49 #define START_PFN (NODE_DATA(0)->bdata->node_boot_start >> PAGE_SHIFT) 50 #define MAX_LOW_PFN (NODE_DATA(0)->bdata->node_low_pfn) 51 #endif 52 53 void (*copy_page)(void *from, void *to); 54 void (*clear_page)(void *to); 55 56 void show_mem(void) 57 { 58 int i, total = 0, reserved = 0; 59 int shared = 0, cached = 0; 60 61 printk("Mem-info:\n"); 62 show_free_areas(); 63 printk("Free swap: %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10)); 64 i = max_mapnr; 65 while (i-- > 0) { 66 total++; 67 if (PageReserved(mem_map+i)) 68 reserved++; 69 else if (PageSwapCache(mem_map+i)) 70 cached++; 71 else if (page_count(mem_map+i)) 72 shared += page_count(mem_map+i) - 1; 73 } 74 printk("%d pages of RAM\n",total); 75 printk("%d reserved pages\n",reserved); 76 printk("%d pages shared\n",shared); 77 printk("%d pages swap cached\n",cached); 78 } 79 80 static void set_pte_phys(unsigned long addr, unsigned long phys, pgprot_t prot) 81 { 82 pgd_t *pgd; 83 pud_t *pud; 84 pmd_t *pmd; 85 pte_t *pte; 86 87 pgd = swapper_pg_dir + pgd_index(addr); 88 if (pgd_none(*pgd)) { 89 pgd_ERROR(*pgd); 90 return; 91 } 92 93 pud = pud_offset(pgd, addr); 94 if (pud_none(*pud)) { 95 pmd = (pmd_t *)get_zeroed_page(GFP_ATOMIC); 96 set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE | _PAGE_USER)); 97 if (pmd != pmd_offset(pud, 0)) { 98 pud_ERROR(*pud); 99 return; 100 } 101 } 102 103 pmd = pmd_offset(pud, addr); 104 if (pmd_none(*pmd)) { 105 pte = (pte_t *)get_zeroed_page(GFP_ATOMIC); 106 set_pmd(pmd, __pmd(__pa(pte) | _KERNPG_TABLE | _PAGE_USER)); 107 if (pte != pte_offset_kernel(pmd, 0)) { 108 pmd_ERROR(*pmd); 109 return; 110 } 111 } 112 113 pte = pte_offset_kernel(pmd, addr); 114 if (!pte_none(*pte)) { 115 pte_ERROR(*pte); 116 return; 117 } 118 119 set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, prot)); 120 121 __flush_tlb_page(get_asid(), addr); 122 } 123 124 /* 125 * As a performance optimization, other platforms preserve the fixmap mapping 126 * across a context switch, we don't presently do this, but this could be done 127 * in a similar fashion as to the wired TLB interface that sh64 uses (by way 128 * of the memorry mapped UTLB configuration) -- this unfortunately forces us to 129 * give up a TLB entry for each mapping we want to preserve. While this may be 130 * viable for a small number of fixmaps, it's not particularly useful for 131 * everything and needs to be carefully evaluated. (ie, we may want this for 132 * the vsyscall page). 133 * 134 * XXX: Perhaps add a _PAGE_WIRED flag or something similar that we can pass 135 * in at __set_fixmap() time to determine the appropriate behavior to follow. 136 * 137 * -- PFM. 138 */ 139 void __set_fixmap(enum fixed_addresses idx, unsigned long phys, pgprot_t prot) 140 { 141 unsigned long address = __fix_to_virt(idx); 142 143 if (idx >= __end_of_fixed_addresses) { 144 BUG(); 145 return; 146 } 147 148 set_pte_phys(address, phys, prot); 149 } 150 151 /* References to section boundaries */ 152 153 extern char _text, _etext, _edata, __bss_start, _end; 154 extern char __init_begin, __init_end; 155 156 /* 157 * paging_init() sets up the page tables 158 * 159 * This routines also unmaps the page at virtual kernel address 0, so 160 * that we can trap those pesky NULL-reference errors in the kernel. 161 */ 162 void __init paging_init(void) 163 { 164 unsigned long zones_size[MAX_NR_ZONES] = { 0, }; 165 166 /* 167 * Setup some defaults for the zone sizes.. these should be safe 168 * regardless of distcontiguous memory or MMU settings. 169 */ 170 zones_size[ZONE_DMA] = 0 >> PAGE_SHIFT; 171 zones_size[ZONE_NORMAL] = __MEMORY_SIZE >> PAGE_SHIFT; 172 #ifdef CONFIG_HIGHMEM 173 zones_size[ZONE_HIGHMEM] = 0 >> PAGE_SHIFT; 174 #endif 175 176 #ifdef CONFIG_MMU 177 /* 178 * If we have an MMU, and want to be using it .. we need to adjust 179 * the zone sizes accordingly, in addition to turning it on. 180 */ 181 { 182 unsigned long max_dma, low, start_pfn; 183 pgd_t *pg_dir; 184 int i; 185 186 /* We don't need kernel mapping as hardware support that. */ 187 pg_dir = swapper_pg_dir; 188 189 for (i = 0; i < PTRS_PER_PGD; i++) 190 pgd_val(pg_dir[i]) = 0; 191 192 /* Turn on the MMU */ 193 enable_mmu(); 194 195 /* Fixup the zone sizes */ 196 start_pfn = START_PFN; 197 max_dma = virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT; 198 low = MAX_LOW_PFN; 199 200 if (low < max_dma) { 201 zones_size[ZONE_DMA] = low - start_pfn; 202 zones_size[ZONE_NORMAL] = 0; 203 } else { 204 zones_size[ZONE_DMA] = max_dma - start_pfn; 205 zones_size[ZONE_NORMAL] = low - max_dma; 206 } 207 } 208 209 #elif defined(CONFIG_CPU_SH3) || defined(CONFIG_CPU_SH4) 210 /* 211 * If we don't have CONFIG_MMU set and the processor in question 212 * still has an MMU, care needs to be taken to make sure it doesn't 213 * stay on.. Since the boot loader could have potentially already 214 * turned it on, and we clearly don't want it, we simply turn it off. 215 * 216 * We don't need to do anything special for the zone sizes, since the 217 * default values that were already configured up above should be 218 * satisfactory. 219 */ 220 disable_mmu(); 221 #endif 222 NODE_DATA(0)->node_mem_map = NULL; 223 free_area_init_node(0, NODE_DATA(0), zones_size, __MEMORY_START >> PAGE_SHIFT, 0); 224 } 225 226 static struct kcore_list kcore_mem, kcore_vmalloc; 227 228 void __init mem_init(void) 229 { 230 extern unsigned long empty_zero_page[1024]; 231 int codesize, reservedpages, datasize, initsize; 232 int tmp; 233 extern unsigned long memory_start; 234 235 #ifdef CONFIG_MMU 236 high_memory = (void *)__va(MAX_LOW_PFN * PAGE_SIZE); 237 #else 238 extern unsigned long memory_end; 239 240 high_memory = (void *)(memory_end & PAGE_MASK); 241 #endif 242 243 max_mapnr = num_physpages = MAP_NR(high_memory) - MAP_NR(memory_start); 244 245 /* clear the zero-page */ 246 memset(empty_zero_page, 0, PAGE_SIZE); 247 __flush_wback_region(empty_zero_page, PAGE_SIZE); 248 249 /* 250 * Setup wrappers for copy/clear_page(), these will get overridden 251 * later in the boot process if a better method is available. 252 */ 253 #ifdef CONFIG_MMU 254 copy_page = copy_page_slow; 255 clear_page = clear_page_slow; 256 #else 257 copy_page = copy_page_nommu; 258 clear_page = clear_page_nommu; 259 #endif 260 261 /* this will put all low memory onto the freelists */ 262 totalram_pages += free_all_bootmem_node(NODE_DATA(0)); 263 reservedpages = 0; 264 for (tmp = 0; tmp < num_physpages; tmp++) 265 /* 266 * Only count reserved RAM pages 267 */ 268 if (PageReserved(mem_map+tmp)) 269 reservedpages++; 270 271 codesize = (unsigned long) &_etext - (unsigned long) &_text; 272 datasize = (unsigned long) &_edata - (unsigned long) &_etext; 273 initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin; 274 275 kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT); 276 kclist_add(&kcore_vmalloc, (void *)VMALLOC_START, 277 VMALLOC_END - VMALLOC_START); 278 279 printk(KERN_INFO "Memory: %luk/%luk available (%dk kernel code, " 280 "%dk reserved, %dk data, %dk init)\n", 281 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10), 282 max_mapnr << (PAGE_SHIFT-10), 283 codesize >> 10, 284 reservedpages << (PAGE_SHIFT-10), 285 datasize >> 10, 286 initsize >> 10); 287 288 p3_cache_init(); 289 290 /* Initialize the vDSO */ 291 vsyscall_init(); 292 } 293 294 void free_initmem(void) 295 { 296 unsigned long addr; 297 298 addr = (unsigned long)(&__init_begin); 299 for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) { 300 ClearPageReserved(virt_to_page(addr)); 301 init_page_count(virt_to_page(addr)); 302 free_page(addr); 303 totalram_pages++; 304 } 305 printk ("Freeing unused kernel memory: %dk freed\n", (&__init_end - &__init_begin) >> 10); 306 } 307 308 #ifdef CONFIG_BLK_DEV_INITRD 309 void free_initrd_mem(unsigned long start, unsigned long end) 310 { 311 unsigned long p; 312 for (p = start; p < end; p += PAGE_SIZE) { 313 ClearPageReserved(virt_to_page(p)); 314 init_page_count(virt_to_page(p)); 315 free_page(p); 316 totalram_pages++; 317 } 318 printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10); 319 } 320 #endif 321 322