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 #ifdef CONFIG_MMU 81 static void set_pte_phys(unsigned long addr, unsigned long phys, pgprot_t prot) 82 { 83 pgd_t *pgd; 84 pud_t *pud; 85 pmd_t *pmd; 86 pte_t *pte; 87 88 pgd = pgd_offset_k(addr); 89 if (pgd_none(*pgd)) { 90 pgd_ERROR(*pgd); 91 return; 92 } 93 94 pud = pud_alloc(NULL, pgd, addr); 95 if (unlikely(!pud)) { 96 pud_ERROR(*pud); 97 return; 98 } 99 100 pmd = pmd_alloc(NULL, pud, addr); 101 if (unlikely(!pmd)) { 102 pmd_ERROR(*pmd); 103 return; 104 } 105 106 pte = pte_offset_kernel(pmd, addr); 107 if (!pte_none(*pte)) { 108 pte_ERROR(*pte); 109 return; 110 } 111 112 set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, prot)); 113 114 __flush_tlb_page(get_asid(), addr); 115 } 116 117 /* 118 * As a performance optimization, other platforms preserve the fixmap mapping 119 * across a context switch, we don't presently do this, but this could be done 120 * in a similar fashion as to the wired TLB interface that sh64 uses (by way 121 * of the memorry mapped UTLB configuration) -- this unfortunately forces us to 122 * give up a TLB entry for each mapping we want to preserve. While this may be 123 * viable for a small number of fixmaps, it's not particularly useful for 124 * everything and needs to be carefully evaluated. (ie, we may want this for 125 * the vsyscall page). 126 * 127 * XXX: Perhaps add a _PAGE_WIRED flag or something similar that we can pass 128 * in at __set_fixmap() time to determine the appropriate behavior to follow. 129 * 130 * -- PFM. 131 */ 132 void __set_fixmap(enum fixed_addresses idx, unsigned long phys, pgprot_t prot) 133 { 134 unsigned long address = __fix_to_virt(idx); 135 136 if (idx >= __end_of_fixed_addresses) { 137 BUG(); 138 return; 139 } 140 141 set_pte_phys(address, phys, prot); 142 } 143 #endif /* CONFIG_MMU */ 144 145 /* References to section boundaries */ 146 147 extern char _text, _etext, _edata, __bss_start, _end; 148 extern char __init_begin, __init_end; 149 150 /* 151 * paging_init() sets up the page tables 152 */ 153 void __init paging_init(void) 154 { 155 unsigned long zones_size[MAX_NR_ZONES] = { 0, }; 156 157 /* 158 * Setup some defaults for the zone sizes.. these should be safe 159 * regardless of distcontiguous memory or MMU settings. 160 */ 161 zones_size[ZONE_DMA] = 0 >> PAGE_SHIFT; 162 zones_size[ZONE_NORMAL] = __MEMORY_SIZE >> PAGE_SHIFT; 163 #ifdef CONFIG_HIGHMEM 164 zones_size[ZONE_HIGHMEM] = 0 >> PAGE_SHIFT; 165 #endif 166 167 #ifdef CONFIG_MMU 168 /* 169 * If we have an MMU, and want to be using it .. we need to adjust 170 * the zone sizes accordingly, in addition to turning it on. 171 */ 172 { 173 unsigned long max_dma, low, start_pfn; 174 175 /* We don't need to map the kernel through the TLB, as 176 * it is permanatly mapped using P1. So clear the 177 * entire pgd. */ 178 memset(swapper_pg_dir, 0, sizeof(swapper_pg_dir)); 179 180 /* Turn on the MMU */ 181 enable_mmu(); 182 183 /* Fixup the zone sizes */ 184 start_pfn = START_PFN; 185 max_dma = virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT; 186 low = MAX_LOW_PFN; 187 188 if (low < max_dma) { 189 zones_size[ZONE_DMA] = low - start_pfn; 190 zones_size[ZONE_NORMAL] = 0; 191 } else { 192 zones_size[ZONE_DMA] = max_dma - start_pfn; 193 zones_size[ZONE_NORMAL] = low - max_dma; 194 } 195 } 196 197 /* Set an initial value for the MMU.TTB so we don't have to 198 * check for a null value. */ 199 set_TTB(swapper_pg_dir); 200 201 #elif defined(CONFIG_CPU_SH3) || defined(CONFIG_CPU_SH4) 202 /* 203 * If we don't have CONFIG_MMU set and the processor in question 204 * still has an MMU, care needs to be taken to make sure it doesn't 205 * stay on.. Since the boot loader could have potentially already 206 * turned it on, and we clearly don't want it, we simply turn it off. 207 * 208 * We don't need to do anything special for the zone sizes, since the 209 * default values that were already configured up above should be 210 * satisfactory. 211 */ 212 disable_mmu(); 213 #endif 214 NODE_DATA(0)->node_mem_map = NULL; 215 free_area_init_node(0, NODE_DATA(0), zones_size, __MEMORY_START >> PAGE_SHIFT, 0); 216 } 217 218 static struct kcore_list kcore_mem, kcore_vmalloc; 219 220 void __init mem_init(void) 221 { 222 int codesize, reservedpages, datasize, initsize; 223 int tmp; 224 extern unsigned long memory_start; 225 226 #ifdef CONFIG_MMU 227 high_memory = (void *)__va(MAX_LOW_PFN * PAGE_SIZE); 228 #else 229 extern unsigned long memory_end; 230 231 high_memory = (void *)(memory_end & PAGE_MASK); 232 #endif 233 234 max_mapnr = num_physpages = MAP_NR(high_memory) - MAP_NR(memory_start); 235 236 /* clear the zero-page */ 237 memset(empty_zero_page, 0, PAGE_SIZE); 238 __flush_wback_region(empty_zero_page, PAGE_SIZE); 239 240 /* 241 * Setup wrappers for copy/clear_page(), these will get overridden 242 * later in the boot process if a better method is available. 243 */ 244 #ifdef CONFIG_MMU 245 copy_page = copy_page_slow; 246 clear_page = clear_page_slow; 247 #else 248 copy_page = copy_page_nommu; 249 clear_page = clear_page_nommu; 250 #endif 251 252 /* this will put all low memory onto the freelists */ 253 totalram_pages += free_all_bootmem_node(NODE_DATA(0)); 254 reservedpages = 0; 255 for (tmp = 0; tmp < num_physpages; tmp++) 256 /* 257 * Only count reserved RAM pages 258 */ 259 if (PageReserved(mem_map+tmp)) 260 reservedpages++; 261 262 codesize = (unsigned long) &_etext - (unsigned long) &_text; 263 datasize = (unsigned long) &_edata - (unsigned long) &_etext; 264 initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin; 265 266 kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT); 267 kclist_add(&kcore_vmalloc, (void *)VMALLOC_START, 268 VMALLOC_END - VMALLOC_START); 269 270 printk(KERN_INFO "Memory: %luk/%luk available (%dk kernel code, " 271 "%dk reserved, %dk data, %dk init)\n", 272 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10), 273 max_mapnr << (PAGE_SHIFT-10), 274 codesize >> 10, 275 reservedpages << (PAGE_SHIFT-10), 276 datasize >> 10, 277 initsize >> 10); 278 279 p3_cache_init(); 280 281 /* Initialize the vDSO */ 282 vsyscall_init(); 283 } 284 285 void free_initmem(void) 286 { 287 unsigned long addr; 288 289 addr = (unsigned long)(&__init_begin); 290 for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) { 291 ClearPageReserved(virt_to_page(addr)); 292 init_page_count(virt_to_page(addr)); 293 free_page(addr); 294 totalram_pages++; 295 } 296 printk ("Freeing unused kernel memory: %dk freed\n", (&__init_end - &__init_begin) >> 10); 297 } 298 299 #ifdef CONFIG_BLK_DEV_INITRD 300 void free_initrd_mem(unsigned long start, unsigned long end) 301 { 302 unsigned long p; 303 for (p = start; p < end; p += PAGE_SIZE) { 304 ClearPageReserved(virt_to_page(p)); 305 init_page_count(virt_to_page(p)); 306 free_page(p); 307 totalram_pages++; 308 } 309 printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10); 310 } 311 #endif 312 313