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