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 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 pmd_t *pmd; 84 pte_t *pte; 85 86 pgd = swapper_pg_dir + pgd_index(addr); 87 if (pgd_none(*pgd)) { 88 pgd_ERROR(*pgd); 89 return; 90 } 91 92 pmd = pmd_offset(pgd, addr); 93 if (pmd_none(*pmd)) { 94 pte = (pte_t *)get_zeroed_page(GFP_ATOMIC); 95 set_pmd(pmd, __pmd(__pa(pte) | _KERNPG_TABLE | _PAGE_USER)); 96 if (pte != pte_offset_kernel(pmd, 0)) { 97 pmd_ERROR(*pmd); 98 return; 99 } 100 } 101 102 pte = pte_offset_kernel(pmd, addr); 103 if (!pte_none(*pte)) { 104 pte_ERROR(*pte); 105 return; 106 } 107 108 set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, prot)); 109 110 __flush_tlb_page(get_asid(), addr); 111 } 112 113 /* 114 * As a performance optimization, other platforms preserve the fixmap mapping 115 * across a context switch, we don't presently do this, but this could be done 116 * in a similar fashion as to the wired TLB interface that sh64 uses (by way 117 * of the memorry mapped UTLB configuration) -- this unfortunately forces us to 118 * give up a TLB entry for each mapping we want to preserve. While this may be 119 * viable for a small number of fixmaps, it's not particularly useful for 120 * everything and needs to be carefully evaluated. (ie, we may want this for 121 * the vsyscall page). 122 * 123 * XXX: Perhaps add a _PAGE_WIRED flag or something similar that we can pass 124 * in at __set_fixmap() time to determine the appropriate behavior to follow. 125 * 126 * -- PFM. 127 */ 128 void __set_fixmap(enum fixed_addresses idx, unsigned long phys, pgprot_t prot) 129 { 130 unsigned long address = __fix_to_virt(idx); 131 132 if (idx >= __end_of_fixed_addresses) { 133 BUG(); 134 return; 135 } 136 137 set_pte_phys(address, phys, prot); 138 } 139 140 /* References to section boundaries */ 141 142 extern char _text, _etext, _edata, __bss_start, _end; 143 extern char __init_begin, __init_end; 144 145 /* 146 * paging_init() sets up the page tables 147 * 148 * This routines also unmaps the page at virtual kernel address 0, so 149 * that we can trap those pesky NULL-reference errors in the kernel. 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 pgd_t *pg_dir; 173 int i; 174 175 /* We don't need kernel mapping as hardware support that. */ 176 pg_dir = swapper_pg_dir; 177 178 for (i = 0; i < PTRS_PER_PGD; i++) 179 pgd_val(pg_dir[i]) = 0; 180 181 /* Turn on the MMU */ 182 enable_mmu(); 183 184 /* Fixup the zone sizes */ 185 start_pfn = START_PFN; 186 max_dma = virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT; 187 low = MAX_LOW_PFN; 188 189 if (low < max_dma) { 190 zones_size[ZONE_DMA] = low - start_pfn; 191 zones_size[ZONE_NORMAL] = 0; 192 } else { 193 zones_size[ZONE_DMA] = max_dma - start_pfn; 194 zones_size[ZONE_NORMAL] = low - max_dma; 195 } 196 } 197 198 #elif defined(CONFIG_CPU_SH3) || defined(CONFIG_CPU_SH4) 199 /* 200 * If we don't have CONFIG_MMU set and the processor in question 201 * still has an MMU, care needs to be taken to make sure it doesn't 202 * stay on.. Since the boot loader could have potentially already 203 * turned it on, and we clearly don't want it, we simply turn it off. 204 * 205 * We don't need to do anything special for the zone sizes, since the 206 * default values that were already configured up above should be 207 * satisfactory. 208 */ 209 disable_mmu(); 210 #endif 211 NODE_DATA(0)->node_mem_map = NULL; 212 free_area_init_node(0, NODE_DATA(0), zones_size, __MEMORY_START >> PAGE_SHIFT, 0); 213 } 214 215 void __init mem_init(void) 216 { 217 extern unsigned long empty_zero_page[1024]; 218 int codesize, reservedpages, datasize, initsize; 219 int tmp; 220 extern unsigned long memory_start; 221 222 #ifdef CONFIG_MMU 223 high_memory = (void *)__va(MAX_LOW_PFN * PAGE_SIZE); 224 #else 225 extern unsigned long memory_end; 226 227 high_memory = (void *)(memory_end & PAGE_MASK); 228 #endif 229 230 max_mapnr = num_physpages = MAP_NR(high_memory) - MAP_NR(memory_start); 231 232 /* clear the zero-page */ 233 memset(empty_zero_page, 0, PAGE_SIZE); 234 __flush_wback_region(empty_zero_page, PAGE_SIZE); 235 236 /* 237 * Setup wrappers for copy/clear_page(), these will get overridden 238 * later in the boot process if a better method is available. 239 */ 240 copy_page = copy_page_slow; 241 clear_page = clear_page_slow; 242 243 /* this will put all low memory onto the freelists */ 244 totalram_pages += free_all_bootmem_node(NODE_DATA(0)); 245 reservedpages = 0; 246 for (tmp = 0; tmp < num_physpages; tmp++) 247 /* 248 * Only count reserved RAM pages 249 */ 250 if (PageReserved(mem_map+tmp)) 251 reservedpages++; 252 253 codesize = (unsigned long) &_etext - (unsigned long) &_text; 254 datasize = (unsigned long) &_edata - (unsigned long) &_etext; 255 initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin; 256 257 printk("Memory: %luk/%luk available (%dk kernel code, %dk reserved, %dk data, %dk init)\n", 258 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10), 259 max_mapnr << (PAGE_SHIFT-10), 260 codesize >> 10, 261 reservedpages << (PAGE_SHIFT-10), 262 datasize >> 10, 263 initsize >> 10); 264 265 p3_cache_init(); 266 } 267 268 void free_initmem(void) 269 { 270 unsigned long addr; 271 272 addr = (unsigned long)(&__init_begin); 273 for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) { 274 ClearPageReserved(virt_to_page(addr)); 275 init_page_count(virt_to_page(addr)); 276 free_page(addr); 277 totalram_pages++; 278 } 279 printk ("Freeing unused kernel memory: %dk freed\n", (&__init_end - &__init_begin) >> 10); 280 } 281 282 #ifdef CONFIG_BLK_DEV_INITRD 283 void free_initrd_mem(unsigned long start, unsigned long end) 284 { 285 unsigned long p; 286 for (p = start; p < end; p += PAGE_SIZE) { 287 ClearPageReserved(virt_to_page(p)); 288 init_page_count(virt_to_page(p)); 289 free_page(p); 290 totalram_pages++; 291 } 292 printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10); 293 } 294 #endif 295 296