arch/sh/mm/init.c

   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 */