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 #ifdef CONFIG_DISCONTIGMEM 55 pg_data_t discontig_page_data[MAX_NUMNODES]; 56 bootmem_data_t discontig_node_bdata[MAX_NUMNODES]; 57 #endif 58 59 void (*copy_page)(void *from, void *to); 60 void (*clear_page)(void *to); 61 62 void show_mem(void) 63 { 64 int i, total = 0, reserved = 0; 65 int shared = 0, cached = 0; 66 67 printk("Mem-info:\n"); 68 show_free_areas(); 69 printk("Free swap: %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10)); 70 i = max_mapnr; 71 while (i-- > 0) { 72 total++; 73 if (PageReserved(mem_map+i)) 74 reserved++; 75 else if (PageSwapCache(mem_map+i)) 76 cached++; 77 else if (page_count(mem_map+i)) 78 shared += page_count(mem_map+i) - 1; 79 } 80 printk("%d pages of RAM\n",total); 81 printk("%d reserved pages\n",reserved); 82 printk("%d pages shared\n",shared); 83 printk("%d pages swap cached\n",cached); 84 } 85 86 static void set_pte_phys(unsigned long addr, unsigned long phys, pgprot_t prot) 87 { 88 pgd_t *pgd; 89 pmd_t *pmd; 90 pte_t *pte; 91 92 pgd = swapper_pg_dir + pgd_index(addr); 93 if (pgd_none(*pgd)) { 94 pgd_ERROR(*pgd); 95 return; 96 } 97 98 pmd = pmd_offset(pgd, addr); 99 if (pmd_none(*pmd)) { 100 pte = (pte_t *)get_zeroed_page(GFP_ATOMIC); 101 set_pmd(pmd, __pmd(__pa(pte) | _KERNPG_TABLE | _PAGE_USER)); 102 if (pte != pte_offset_kernel(pmd, 0)) { 103 pmd_ERROR(*pmd); 104 return; 105 } 106 } 107 108 pte = pte_offset_kernel(pmd, addr); 109 if (!pte_none(*pte)) { 110 pte_ERROR(*pte); 111 return; 112 } 113 114 set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, prot)); 115 116 __flush_tlb_page(get_asid(), addr); 117 } 118 119 /* 120 * As a performance optimization, other platforms preserve the fixmap mapping 121 * across a context switch, we don't presently do this, but this could be done 122 * in a similar fashion as to the wired TLB interface that sh64 uses (by way 123 * of the memorry mapped UTLB configuration) -- this unfortunately forces us to 124 * give up a TLB entry for each mapping we want to preserve. While this may be 125 * viable for a small number of fixmaps, it's not particularly useful for 126 * everything and needs to be carefully evaluated. (ie, we may want this for 127 * the vsyscall page). 128 * 129 * XXX: Perhaps add a _PAGE_WIRED flag or something similar that we can pass 130 * in at __set_fixmap() time to determine the appropriate behavior to follow. 131 * 132 * -- PFM. 133 */ 134 void __set_fixmap(enum fixed_addresses idx, unsigned long phys, pgprot_t prot) 135 { 136 unsigned long address = __fix_to_virt(idx); 137 138 if (idx >= __end_of_fixed_addresses) { 139 BUG(); 140 return; 141 } 142 143 set_pte_phys(address, phys, prot); 144 } 145 146 /* References to section boundaries */ 147 148 extern char _text, _etext, _edata, __bss_start, _end; 149 extern char __init_begin, __init_end; 150 151 /* 152 * paging_init() sets up the page tables 153 * 154 * This routines also unmaps the page at virtual kernel address 0, so 155 * that we can trap those pesky NULL-reference errors in the kernel. 156 */ 157 void __init paging_init(void) 158 { 159 unsigned long zones_size[MAX_NR_ZONES] = { 0, }; 160 161 /* 162 * Setup some defaults for the zone sizes.. these should be safe 163 * regardless of distcontiguous memory or MMU settings. 164 */ 165 zones_size[ZONE_DMA] = 0 >> PAGE_SHIFT; 166 zones_size[ZONE_NORMAL] = __MEMORY_SIZE >> PAGE_SHIFT; 167 #ifdef CONFIG_HIGHMEM 168 zones_size[ZONE_HIGHMEM] = 0 >> PAGE_SHIFT; 169 #endif 170 171 #ifdef CONFIG_MMU 172 /* 173 * If we have an MMU, and want to be using it .. we need to adjust 174 * the zone sizes accordingly, in addition to turning it on. 175 */ 176 { 177 unsigned long max_dma, low, start_pfn; 178 pgd_t *pg_dir; 179 int i; 180 181 /* We don't need kernel mapping as hardware support that. */ 182 pg_dir = swapper_pg_dir; 183 184 for (i = 0; i < PTRS_PER_PGD; i++) 185 pgd_val(pg_dir[i]) = 0; 186 187 /* Turn on the MMU */ 188 enable_mmu(); 189 190 /* Fixup the zone sizes */ 191 start_pfn = START_PFN; 192 max_dma = virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT; 193 low = MAX_LOW_PFN; 194 195 if (low < max_dma) { 196 zones_size[ZONE_DMA] = low - start_pfn; 197 zones_size[ZONE_NORMAL] = 0; 198 } else { 199 zones_size[ZONE_DMA] = max_dma - start_pfn; 200 zones_size[ZONE_NORMAL] = low - max_dma; 201 } 202 } 203 204 #elif defined(CONFIG_CPU_SH3) || defined(CONFIG_CPU_SH4) 205 /* 206 * If we don't have CONFIG_MMU set and the processor in question 207 * still has an MMU, care needs to be taken to make sure it doesn't 208 * stay on.. Since the boot loader could have potentially already 209 * turned it on, and we clearly don't want it, we simply turn it off. 210 * 211 * We don't need to do anything special for the zone sizes, since the 212 * default values that were already configured up above should be 213 * satisfactory. 214 */ 215 disable_mmu(); 216 #endif 217 NODE_DATA(0)->node_mem_map = NULL; 218 free_area_init_node(0, NODE_DATA(0), zones_size, __MEMORY_START >> PAGE_SHIFT, 0); 219 220 #ifdef CONFIG_DISCONTIGMEM 221 /* 222 * And for discontig, do some more fixups on the zone sizes.. 223 */ 224 zones_size[ZONE_DMA] = __MEMORY_SIZE_2ND >> PAGE_SHIFT; 225 zones_size[ZONE_NORMAL] = 0; 226 free_area_init_node(1, NODE_DATA(1), zones_size, __MEMORY_START_2ND >> PAGE_SHIFT, 0); 227 #endif 228 } 229 230 void __init mem_init(void) 231 { 232 extern unsigned long empty_zero_page[1024]; 233 int codesize, reservedpages, datasize, initsize; 234 int tmp; 235 extern unsigned long memory_start; 236 237 #ifdef CONFIG_MMU 238 high_memory = (void *)__va(MAX_LOW_PFN * PAGE_SIZE); 239 #else 240 extern unsigned long memory_end; 241 242 high_memory = (void *)(memory_end & PAGE_MASK); 243 #endif 244 245 max_mapnr = num_physpages = MAP_NR(high_memory) - MAP_NR(memory_start); 246 247 /* clear the zero-page */ 248 memset(empty_zero_page, 0, PAGE_SIZE); 249 __flush_wback_region(empty_zero_page, PAGE_SIZE); 250 251 /* 252 * Setup wrappers for copy/clear_page(), these will get overridden 253 * later in the boot process if a better method is available. 254 */ 255 copy_page = copy_page_slow; 256 clear_page = clear_page_slow; 257 258 /* this will put all low memory onto the freelists */ 259 totalram_pages += free_all_bootmem_node(NODE_DATA(0)); 260 #ifdef CONFIG_DISCONTIGMEM 261 totalram_pages += free_all_bootmem_node(NODE_DATA(1)); 262 #endif 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 printk("Memory: %luk/%luk available (%dk kernel code, %dk reserved, %dk data, %dk init)\n", 276 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10), 277 max_mapnr << (PAGE_SHIFT-10), 278 codesize >> 10, 279 reservedpages << (PAGE_SHIFT-10), 280 datasize >> 10, 281 initsize >> 10); 282 283 p3_cache_init(); 284 } 285 286 void free_initmem(void) 287 { 288 unsigned long addr; 289 290 addr = (unsigned long)(&__init_begin); 291 for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) { 292 ClearPageReserved(virt_to_page(addr)); 293 set_page_count(virt_to_page(addr), 1); 294 free_page(addr); 295 totalram_pages++; 296 } 297 printk ("Freeing unused kernel memory: %dk freed\n", (&__init_end - &__init_begin) >> 10); 298 } 299 300 #ifdef CONFIG_BLK_DEV_INITRD 301 void free_initrd_mem(unsigned long start, unsigned long end) 302 { 303 unsigned long p; 304 for (p = start; p < end; p += PAGE_SIZE) { 305 ClearPageReserved(virt_to_page(p)); 306 set_page_count(virt_to_page(p), 1); 307 free_page(p); 308 totalram_pages++; 309 } 310 printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10); 311 } 312 #endif 313 314