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 #ifdef CONFIG_MMU 43 /* It'd be good if these lines were in the standard header file. */ 44 #define START_PFN (NODE_DATA(0)->bdata->node_boot_start >> PAGE_SHIFT) 45 #define MAX_LOW_PFN (NODE_DATA(0)->bdata->node_low_pfn) 46 #endif 47 48 void (*copy_page)(void *from, void *to); 49 void (*clear_page)(void *to); 50 51 void show_mem(void) 52 { 53 int i, total = 0, reserved = 0; 54 int shared = 0, cached = 0; 55 56 printk("Mem-info:\n"); 57 show_free_areas(); 58 printk("Free swap: %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10)); 59 i = max_mapnr; 60 while (i-- > 0) { 61 total++; 62 if (PageReserved(mem_map+i)) 63 reserved++; 64 else if (PageSwapCache(mem_map+i)) 65 cached++; 66 else if (page_count(mem_map+i)) 67 shared += page_count(mem_map+i) - 1; 68 } 69 printk("%d pages of RAM\n",total); 70 printk("%d reserved pages\n",reserved); 71 printk("%d pages shared\n",shared); 72 printk("%d pages swap cached\n",cached); 73 } 74 75 #ifdef CONFIG_MMU 76 static void set_pte_phys(unsigned long addr, unsigned long phys, pgprot_t prot) 77 { 78 pgd_t *pgd; 79 pud_t *pud; 80 pmd_t *pmd; 81 pte_t *pte; 82 83 pgd = pgd_offset_k(addr); 84 if (pgd_none(*pgd)) { 85 pgd_ERROR(*pgd); 86 return; 87 } 88 89 pud = pud_alloc(NULL, pgd, addr); 90 if (unlikely(!pud)) { 91 pud_ERROR(*pud); 92 return; 93 } 94 95 pmd = pmd_alloc(NULL, pud, addr); 96 if (unlikely(!pmd)) { 97 pmd_ERROR(*pmd); 98 return; 99 } 100 101 pte = pte_offset_kernel(pmd, addr); 102 if (!pte_none(*pte)) { 103 pte_ERROR(*pte); 104 return; 105 } 106 107 set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, prot)); 108 109 flush_tlb_one(get_asid(), addr); 110 } 111 112 /* 113 * As a performance optimization, other platforms preserve the fixmap mapping 114 * across a context switch, we don't presently do this, but this could be done 115 * in a similar fashion as to the wired TLB interface that sh64 uses (by way 116 * of the memorry mapped UTLB configuration) -- this unfortunately forces us to 117 * give up a TLB entry for each mapping we want to preserve. While this may be 118 * viable for a small number of fixmaps, it's not particularly useful for 119 * everything and needs to be carefully evaluated. (ie, we may want this for 120 * the vsyscall page). 121 * 122 * XXX: Perhaps add a _PAGE_WIRED flag or something similar that we can pass 123 * in at __set_fixmap() time to determine the appropriate behavior to follow. 124 * 125 * -- PFM. 126 */ 127 void __set_fixmap(enum fixed_addresses idx, unsigned long phys, pgprot_t prot) 128 { 129 unsigned long address = __fix_to_virt(idx); 130 131 if (idx >= __end_of_fixed_addresses) { 132 BUG(); 133 return; 134 } 135 136 set_pte_phys(address, phys, prot); 137 } 138 #endif /* CONFIG_MMU */ 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 void __init paging_init(void) 149 { 150 unsigned long zones_size[MAX_NR_ZONES] = { 0, }; 151 152 /* 153 * Setup some defaults for the zone sizes.. these should be safe 154 * regardless of distcontiguous memory or MMU settings. 155 */ 156 zones_size[ZONE_NORMAL] = __MEMORY_SIZE >> PAGE_SHIFT; 157 #ifdef CONFIG_HIGHMEM 158 zones_size[ZONE_HIGHMEM] = 0 >> PAGE_SHIFT; 159 #endif 160 161 #ifdef CONFIG_MMU 162 /* 163 * If we have an MMU, and want to be using it .. we need to adjust 164 * the zone sizes accordingly, in addition to turning it on. 165 */ 166 { 167 /* We don't need to map the kernel through the TLB, as 168 * it is permanatly mapped using P1. So clear the 169 * entire pgd. */ 170 memset(swapper_pg_dir, 0, sizeof(swapper_pg_dir)); 171 172 /* Turn on the MMU */ 173 enable_mmu(); 174 zones_size[ZONE_NORMAL] = MAX_LOW_PFN - START_PFN; 175 } 176 177 /* Set an initial value for the MMU.TTB so we don't have to 178 * check for a null value. */ 179 set_TTB(swapper_pg_dir); 180 181 #elif defined(CONFIG_CPU_SH3) || defined(CONFIG_CPU_SH4) 182 /* 183 * If we don't have CONFIG_MMU set and the processor in question 184 * still has an MMU, care needs to be taken to make sure it doesn't 185 * stay on.. Since the boot loader could have potentially already 186 * turned it on, and we clearly don't want it, we simply turn it off. 187 * 188 * We don't need to do anything special for the zone sizes, since the 189 * default values that were already configured up above should be 190 * satisfactory. 191 */ 192 disable_mmu(); 193 #endif 194 NODE_DATA(0)->node_mem_map = NULL; 195 free_area_init_node(0, NODE_DATA(0), zones_size, __MEMORY_START >> PAGE_SHIFT, 0); 196 } 197 198 static struct kcore_list kcore_mem, kcore_vmalloc; 199 200 void __init mem_init(void) 201 { 202 int codesize, reservedpages, datasize, initsize; 203 int tmp; 204 extern unsigned long memory_start; 205 206 #ifdef CONFIG_MMU 207 high_memory = (void *)__va(MAX_LOW_PFN * PAGE_SIZE); 208 #else 209 extern unsigned long memory_end; 210 211 high_memory = (void *)(memory_end & PAGE_MASK); 212 #endif 213 214 max_mapnr = num_physpages = MAP_NR(high_memory) - MAP_NR(memory_start); 215 216 /* clear the zero-page */ 217 memset(empty_zero_page, 0, PAGE_SIZE); 218 __flush_wback_region(empty_zero_page, PAGE_SIZE); 219 220 /* 221 * Setup wrappers for copy/clear_page(), these will get overridden 222 * later in the boot process if a better method is available. 223 */ 224 #ifdef CONFIG_MMU 225 copy_page = copy_page_slow; 226 clear_page = clear_page_slow; 227 #else 228 copy_page = copy_page_nommu; 229 clear_page = clear_page_nommu; 230 #endif 231 232 /* this will put all low memory onto the freelists */ 233 totalram_pages += free_all_bootmem_node(NODE_DATA(0)); 234 reservedpages = 0; 235 for (tmp = 0; tmp < num_physpages; tmp++) 236 /* 237 * Only count reserved RAM pages 238 */ 239 if (PageReserved(mem_map+tmp)) 240 reservedpages++; 241 242 codesize = (unsigned long) &_etext - (unsigned long) &_text; 243 datasize = (unsigned long) &_edata - (unsigned long) &_etext; 244 initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin; 245 246 kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT); 247 kclist_add(&kcore_vmalloc, (void *)VMALLOC_START, 248 VMALLOC_END - VMALLOC_START); 249 250 printk(KERN_INFO "Memory: %luk/%luk available (%dk kernel code, " 251 "%dk reserved, %dk data, %dk init)\n", 252 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10), 253 max_mapnr << (PAGE_SHIFT-10), 254 codesize >> 10, 255 reservedpages << (PAGE_SHIFT-10), 256 datasize >> 10, 257 initsize >> 10); 258 259 p3_cache_init(); 260 261 /* Initialize the vDSO */ 262 vsyscall_init(); 263 } 264 265 void free_initmem(void) 266 { 267 unsigned long addr; 268 269 addr = (unsigned long)(&__init_begin); 270 for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) { 271 ClearPageReserved(virt_to_page(addr)); 272 init_page_count(virt_to_page(addr)); 273 free_page(addr); 274 totalram_pages++; 275 } 276 printk ("Freeing unused kernel memory: %dk freed\n", (&__init_end - &__init_begin) >> 10); 277 } 278 279 #ifdef CONFIG_BLK_DEV_INITRD 280 void free_initrd_mem(unsigned long start, unsigned long end) 281 { 282 unsigned long p; 283 for (p = start; p < end; p += PAGE_SIZE) { 284 ClearPageReserved(virt_to_page(p)); 285 init_page_count(virt_to_page(p)); 286 free_page(p); 287 totalram_pages++; 288 } 289 printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10); 290 } 291 #endif 292 293