1 /* 2 * linux/arch/sh/mm/init.c 3 * 4 * Copyright (C) 1999 Niibe Yutaka 5 * Copyright (C) 2002 - 2007 Paul Mundt 6 * 7 * Based on linux/arch/i386/mm/init.c: 8 * Copyright (C) 1995 Linus Torvalds 9 */ 10 #include <linux/mm.h> 11 #include <linux/swap.h> 12 #include <linux/init.h> 13 #include <linux/bootmem.h> 14 #include <linux/proc_fs.h> 15 #include <linux/pagemap.h> 16 #include <linux/percpu.h> 17 #include <linux/io.h> 18 #include <linux/dma-mapping.h> 19 #include <asm/mmu_context.h> 20 #include <asm/tlb.h> 21 #include <asm/cacheflush.h> 22 #include <asm/sections.h> 23 #include <asm/cache.h> 24 25 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers); 26 pgd_t swapper_pg_dir[PTRS_PER_PGD]; 27 28 #ifdef CONFIG_SUPERH32 29 /* 30 * Handle trivial transitions between cached and uncached 31 * segments, making use of the 1:1 mapping relationship in 32 * 512MB lowmem. 33 * 34 * This is the offset of the uncached section from its cached alias. 35 * Default value only valid in 29 bit mode, in 32bit mode will be 36 * overridden in pmb_init. 37 */ 38 unsigned long cached_to_uncached = P2SEG - P1SEG; 39 #endif 40 41 #ifdef CONFIG_MMU 42 static void set_pte_phys(unsigned long addr, unsigned long phys, pgprot_t prot) 43 { 44 pgd_t *pgd; 45 pud_t *pud; 46 pmd_t *pmd; 47 pte_t *pte; 48 49 pgd = pgd_offset_k(addr); 50 if (pgd_none(*pgd)) { 51 pgd_ERROR(*pgd); 52 return; 53 } 54 55 pud = pud_alloc(NULL, pgd, addr); 56 if (unlikely(!pud)) { 57 pud_ERROR(*pud); 58 return; 59 } 60 61 pmd = pmd_alloc(NULL, pud, addr); 62 if (unlikely(!pmd)) { 63 pmd_ERROR(*pmd); 64 return; 65 } 66 67 pte = pte_offset_kernel(pmd, addr); 68 if (!pte_none(*pte)) { 69 pte_ERROR(*pte); 70 return; 71 } 72 73 set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, prot)); 74 local_flush_tlb_one(get_asid(), addr); 75 } 76 77 /* 78 * As a performance optimization, other platforms preserve the fixmap mapping 79 * across a context switch, we don't presently do this, but this could be done 80 * in a similar fashion as to the wired TLB interface that sh64 uses (by way 81 * of the memory mapped UTLB configuration) -- this unfortunately forces us to 82 * give up a TLB entry for each mapping we want to preserve. While this may be 83 * viable for a small number of fixmaps, it's not particularly useful for 84 * everything and needs to be carefully evaluated. (ie, we may want this for 85 * the vsyscall page). 86 * 87 * XXX: Perhaps add a _PAGE_WIRED flag or something similar that we can pass 88 * in at __set_fixmap() time to determine the appropriate behavior to follow. 89 * 90 * -- PFM. 91 */ 92 void __set_fixmap(enum fixed_addresses idx, unsigned long phys, pgprot_t prot) 93 { 94 unsigned long address = __fix_to_virt(idx); 95 96 if (idx >= __end_of_fixed_addresses) { 97 BUG(); 98 return; 99 } 100 101 set_pte_phys(address, phys, prot); 102 } 103 104 void __init page_table_range_init(unsigned long start, unsigned long end, 105 pgd_t *pgd_base) 106 { 107 pgd_t *pgd; 108 pud_t *pud; 109 pmd_t *pmd; 110 pte_t *pte; 111 int i, j, k; 112 unsigned long vaddr; 113 114 vaddr = start; 115 i = __pgd_offset(vaddr); 116 j = __pud_offset(vaddr); 117 k = __pmd_offset(vaddr); 118 pgd = pgd_base + i; 119 120 for ( ; (i < PTRS_PER_PGD) && (vaddr != end); pgd++, i++) { 121 pud = (pud_t *)pgd; 122 for ( ; (j < PTRS_PER_PUD) && (vaddr != end); pud++, j++) { 123 pmd = (pmd_t *)pud; 124 for (; (k < PTRS_PER_PMD) && (vaddr != end); pmd++, k++) { 125 if (pmd_none(*pmd)) { 126 pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE); 127 pmd_populate_kernel(&init_mm, pmd, pte); 128 BUG_ON(pte != pte_offset_kernel(pmd, 0)); 129 } 130 vaddr += PMD_SIZE; 131 } 132 k = 0; 133 } 134 j = 0; 135 } 136 } 137 #endif /* CONFIG_MMU */ 138 139 /* 140 * paging_init() sets up the page tables 141 */ 142 void __init paging_init(void) 143 { 144 unsigned long max_zone_pfns[MAX_NR_ZONES]; 145 unsigned long vaddr, end; 146 int nid; 147 148 /* We don't need to map the kernel through the TLB, as 149 * it is permanatly mapped using P1. So clear the 150 * entire pgd. */ 151 memset(swapper_pg_dir, 0, sizeof(swapper_pg_dir)); 152 153 /* Set an initial value for the MMU.TTB so we don't have to 154 * check for a null value. */ 155 set_TTB(swapper_pg_dir); 156 157 /* 158 * Populate the relevant portions of swapper_pg_dir so that 159 * we can use the fixmap entries without calling kmalloc. 160 * pte's will be filled in by __set_fixmap(). 161 */ 162 vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK; 163 end = (FIXADDR_TOP + PMD_SIZE - 1) & PMD_MASK; 164 page_table_range_init(vaddr, end, swapper_pg_dir); 165 166 kmap_coherent_init(); 167 168 memset(max_zone_pfns, 0, sizeof(max_zone_pfns)); 169 170 for_each_online_node(nid) { 171 pg_data_t *pgdat = NODE_DATA(nid); 172 unsigned long low, start_pfn; 173 174 start_pfn = pgdat->bdata->node_min_pfn; 175 low = pgdat->bdata->node_low_pfn; 176 177 if (max_zone_pfns[ZONE_NORMAL] < low) 178 max_zone_pfns[ZONE_NORMAL] = low; 179 180 printk("Node %u: start_pfn = 0x%lx, low = 0x%lx\n", 181 nid, start_pfn, low); 182 } 183 184 free_area_init_nodes(max_zone_pfns); 185 186 /* Set up the uncached fixmap */ 187 set_fixmap_nocache(FIX_UNCACHED, __pa(&__uncached_start)); 188 } 189 190 /* 191 * Early initialization for any I/O MMUs we might have. 192 */ 193 static void __init iommu_init(void) 194 { 195 no_iommu_init(); 196 } 197 198 void __init mem_init(void) 199 { 200 int codesize, datasize, initsize; 201 int nid; 202 203 iommu_init(); 204 205 num_physpages = 0; 206 high_memory = NULL; 207 208 for_each_online_node(nid) { 209 pg_data_t *pgdat = NODE_DATA(nid); 210 unsigned long node_pages = 0; 211 void *node_high_memory; 212 213 num_physpages += pgdat->node_present_pages; 214 215 if (pgdat->node_spanned_pages) 216 node_pages = free_all_bootmem_node(pgdat); 217 218 totalram_pages += node_pages; 219 220 node_high_memory = (void *)__va((pgdat->node_start_pfn + 221 pgdat->node_spanned_pages) << 222 PAGE_SHIFT); 223 if (node_high_memory > high_memory) 224 high_memory = node_high_memory; 225 } 226 227 /* Set this up early, so we can take care of the zero page */ 228 cpu_cache_init(); 229 230 /* clear the zero-page */ 231 memset(empty_zero_page, 0, PAGE_SIZE); 232 __flush_wback_region(empty_zero_page, PAGE_SIZE); 233 234 codesize = (unsigned long) &_etext - (unsigned long) &_text; 235 datasize = (unsigned long) &_edata - (unsigned long) &_etext; 236 initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin; 237 238 printk(KERN_INFO "Memory: %luk/%luk available (%dk kernel code, " 239 "%dk data, %dk init)\n", 240 nr_free_pages() << (PAGE_SHIFT-10), 241 num_physpages << (PAGE_SHIFT-10), 242 codesize >> 10, 243 datasize >> 10, 244 initsize >> 10); 245 246 /* Initialize the vDSO */ 247 vsyscall_init(); 248 } 249 250 void free_initmem(void) 251 { 252 unsigned long addr; 253 254 addr = (unsigned long)(&__init_begin); 255 for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) { 256 ClearPageReserved(virt_to_page(addr)); 257 init_page_count(virt_to_page(addr)); 258 free_page(addr); 259 totalram_pages++; 260 } 261 printk("Freeing unused kernel memory: %ldk freed\n", 262 ((unsigned long)&__init_end - 263 (unsigned long)&__init_begin) >> 10); 264 } 265 266 #ifdef CONFIG_BLK_DEV_INITRD 267 void free_initrd_mem(unsigned long start, unsigned long end) 268 { 269 unsigned long p; 270 for (p = start; p < end; p += PAGE_SIZE) { 271 ClearPageReserved(virt_to_page(p)); 272 init_page_count(virt_to_page(p)); 273 free_page(p); 274 totalram_pages++; 275 } 276 printk("Freeing initrd memory: %ldk freed\n", (end - start) >> 10); 277 } 278 #endif 279 280 #if THREAD_SHIFT < PAGE_SHIFT 281 static struct kmem_cache *thread_info_cache; 282 283 struct thread_info *alloc_thread_info(struct task_struct *tsk) 284 { 285 struct thread_info *ti; 286 287 ti = kmem_cache_alloc(thread_info_cache, GFP_KERNEL); 288 if (unlikely(ti == NULL)) 289 return NULL; 290 #ifdef CONFIG_DEBUG_STACK_USAGE 291 memset(ti, 0, THREAD_SIZE); 292 #endif 293 return ti; 294 } 295 296 void free_thread_info(struct thread_info *ti) 297 { 298 kmem_cache_free(thread_info_cache, ti); 299 } 300 301 void thread_info_cache_init(void) 302 { 303 thread_info_cache = kmem_cache_create("thread_info", THREAD_SIZE, 304 THREAD_SIZE, 0, NULL); 305 BUG_ON(thread_info_cache == NULL); 306 } 307 #endif /* THREAD_SHIFT < PAGE_SHIFT */ 308 309 #ifdef CONFIG_MEMORY_HOTPLUG 310 int arch_add_memory(int nid, u64 start, u64 size) 311 { 312 pg_data_t *pgdat; 313 unsigned long start_pfn = start >> PAGE_SHIFT; 314 unsigned long nr_pages = size >> PAGE_SHIFT; 315 int ret; 316 317 pgdat = NODE_DATA(nid); 318 319 /* We only have ZONE_NORMAL, so this is easy.. */ 320 ret = __add_pages(nid, pgdat->node_zones + ZONE_NORMAL, 321 start_pfn, nr_pages); 322 if (unlikely(ret)) 323 printk("%s: Failed, __add_pages() == %d\n", __func__, ret); 324 325 return ret; 326 } 327 EXPORT_SYMBOL_GPL(arch_add_memory); 328 329 #ifdef CONFIG_NUMA 330 int memory_add_physaddr_to_nid(u64 addr) 331 { 332 /* Node 0 for now.. */ 333 return 0; 334 } 335 EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid); 336 #endif 337 338 #endif /* CONFIG_MEMORY_HOTPLUG */ 339 340 #ifdef CONFIG_PMB 341 int __in_29bit_mode(void) 342 { 343 return !(ctrl_inl(PMB_PASCR) & PASCR_SE); 344 } 345 #endif /* CONFIG_PMB */ 346