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 = pgd_offset_k(addr); 88 if (pgd_none(*pgd)) { 89 pgd_ERROR(*pgd); 90 return; 91 } 92 93 pud = pud_alloc(NULL, pgd, addr); 94 if (unlikely(!pud)) { 95 pud_ERROR(*pud); 96 return; 97 } 98 99 pmd = pmd_alloc(NULL, pud, addr); 100 if (unlikely(!pmd)) { 101 pmd_ERROR(*pmd); 102 return; 103 } 104 105 pte = pte_offset_kernel(pmd, addr); 106 if (!pte_none(*pte)) { 107 pte_ERROR(*pte); 108 return; 109 } 110 111 set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, prot)); 112 113 __flush_tlb_page(get_asid(), addr); 114 } 115 116 /* 117 * As a performance optimization, other platforms preserve the fixmap mapping 118 * across a context switch, we don't presently do this, but this could be done 119 * in a similar fashion as to the wired TLB interface that sh64 uses (by way 120 * of the memorry mapped UTLB configuration) -- this unfortunately forces us to 121 * give up a TLB entry for each mapping we want to preserve. While this may be 122 * viable for a small number of fixmaps, it's not particularly useful for 123 * everything and needs to be carefully evaluated. (ie, we may want this for 124 * the vsyscall page). 125 * 126 * XXX: Perhaps add a _PAGE_WIRED flag or something similar that we can pass 127 * in at __set_fixmap() time to determine the appropriate behavior to follow. 128 * 129 * -- PFM. 130 */ 131 void __set_fixmap(enum fixed_addresses idx, unsigned long phys, pgprot_t prot) 132 { 133 unsigned long address = __fix_to_virt(idx); 134 135 if (idx >= __end_of_fixed_addresses) { 136 BUG(); 137 return; 138 } 139 140 set_pte_phys(address, phys, prot); 141 } 142 143 /* References to section boundaries */ 144 145 extern char _text, _etext, _edata, __bss_start, _end; 146 extern char __init_begin, __init_end; 147 148 /* 149 * paging_init() sets up the page tables 150 */ 151 void __init paging_init(void) 152 { 153 unsigned long zones_size[MAX_NR_ZONES] = { 0, }; 154 155 /* 156 * Setup some defaults for the zone sizes.. these should be safe 157 * regardless of distcontiguous memory or MMU settings. 158 */ 159 zones_size[ZONE_DMA] = 0 >> PAGE_SHIFT; 160 zones_size[ZONE_NORMAL] = __MEMORY_SIZE >> PAGE_SHIFT; 161 #ifdef CONFIG_HIGHMEM 162 zones_size[ZONE_HIGHMEM] = 0 >> PAGE_SHIFT; 163 #endif 164 165 #ifdef CONFIG_MMU 166 /* 167 * If we have an MMU, and want to be using it .. we need to adjust 168 * the zone sizes accordingly, in addition to turning it on. 169 */ 170 { 171 unsigned long max_dma, low, start_pfn; 172 173 /* We don't need to map the kernel through the TLB, as 174 * it is permanatly mapped using P1. So clear the 175 * entire pgd. */ 176 memset(swapper_pg_dir, 0, sizeof(swapper_pg_dir)); 177 178 /* Turn on the MMU */ 179 enable_mmu(); 180 181 /* Fixup the zone sizes */ 182 start_pfn = START_PFN; 183 max_dma = virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT; 184 low = MAX_LOW_PFN; 185 186 if (low < max_dma) { 187 zones_size[ZONE_DMA] = low - start_pfn; 188 zones_size[ZONE_NORMAL] = 0; 189 } else { 190 zones_size[ZONE_DMA] = max_dma - start_pfn; 191 zones_size[ZONE_NORMAL] = low - max_dma; 192 } 193 } 194 195 /* Set an initial value for the MMU.TTB so we don't have to 196 * check for a null value. */ 197 set_TTB(swapper_pg_dir); 198 199 #elif defined(CONFIG_CPU_SH3) || defined(CONFIG_CPU_SH4) 200 /* 201 * If we don't have CONFIG_MMU set and the processor in question 202 * still has an MMU, care needs to be taken to make sure it doesn't 203 * stay on.. Since the boot loader could have potentially already 204 * turned it on, and we clearly don't want it, we simply turn it off. 205 * 206 * We don't need to do anything special for the zone sizes, since the 207 * default values that were already configured up above should be 208 * satisfactory. 209 */ 210 disable_mmu(); 211 #endif 212 NODE_DATA(0)->node_mem_map = NULL; 213 free_area_init_node(0, NODE_DATA(0), zones_size, __MEMORY_START >> PAGE_SHIFT, 0); 214 } 215 216 static struct kcore_list kcore_mem, kcore_vmalloc; 217 218 void __init mem_init(void) 219 { 220 int codesize, reservedpages, datasize, initsize; 221 int tmp; 222 extern unsigned long memory_start; 223 224 #ifdef CONFIG_MMU 225 high_memory = (void *)__va(MAX_LOW_PFN * PAGE_SIZE); 226 #else 227 extern unsigned long memory_end; 228 229 high_memory = (void *)(memory_end & PAGE_MASK); 230 #endif 231 232 max_mapnr = num_physpages = MAP_NR(high_memory) - MAP_NR(memory_start); 233 234 /* clear the zero-page */ 235 memset(empty_zero_page, 0, PAGE_SIZE); 236 __flush_wback_region(empty_zero_page, PAGE_SIZE); 237 238 /* 239 * Setup wrappers for copy/clear_page(), these will get overridden 240 * later in the boot process if a better method is available. 241 */ 242 #ifdef CONFIG_MMU 243 copy_page = copy_page_slow; 244 clear_page = clear_page_slow; 245 #else 246 copy_page = copy_page_nommu; 247 clear_page = clear_page_nommu; 248 #endif 249 250 /* this will put all low memory onto the freelists */ 251 totalram_pages += free_all_bootmem_node(NODE_DATA(0)); 252 reservedpages = 0; 253 for (tmp = 0; tmp < num_physpages; tmp++) 254 /* 255 * Only count reserved RAM pages 256 */ 257 if (PageReserved(mem_map+tmp)) 258 reservedpages++; 259 260 codesize = (unsigned long) &_etext - (unsigned long) &_text; 261 datasize = (unsigned long) &_edata - (unsigned long) &_etext; 262 initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin; 263 264 kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT); 265 kclist_add(&kcore_vmalloc, (void *)VMALLOC_START, 266 VMALLOC_END - VMALLOC_START); 267 268 printk(KERN_INFO "Memory: %luk/%luk available (%dk kernel code, " 269 "%dk reserved, %dk data, %dk init)\n", 270 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10), 271 max_mapnr << (PAGE_SHIFT-10), 272 codesize >> 10, 273 reservedpages << (PAGE_SHIFT-10), 274 datasize >> 10, 275 initsize >> 10); 276 277 p3_cache_init(); 278 279 /* Initialize the vDSO */ 280 vsyscall_init(); 281 } 282 283 void free_initmem(void) 284 { 285 unsigned long addr; 286 287 addr = (unsigned long)(&__init_begin); 288 for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) { 289 ClearPageReserved(virt_to_page(addr)); 290 init_page_count(virt_to_page(addr)); 291 free_page(addr); 292 totalram_pages++; 293 } 294 printk ("Freeing unused kernel memory: %dk freed\n", (&__init_end - &__init_begin) >> 10); 295 } 296 297 #ifdef CONFIG_BLK_DEV_INITRD 298 void free_initrd_mem(unsigned long start, unsigned long end) 299 { 300 unsigned long p; 301 for (p = start; p < end; p += PAGE_SIZE) { 302 ClearPageReserved(virt_to_page(p)); 303 init_page_count(virt_to_page(p)); 304 free_page(p); 305 totalram_pages++; 306 } 307 printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10); 308 } 309 #endif 310 311