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 <asm/mmu_context.h>
  19 #include <asm/tlb.h>
  20 #include <asm/cacheflush.h>
  21 #include <asm/sections.h>
  22 #include <asm/cache.h>
  23
  24 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
  25 pgd_t swapper_pg_dir[PTRS_PER_PGD];
  26 unsigned long cached_to_uncached = 0;
  27
  28 void show_mem(void)
  29 {
  30         int total = 0, reserved = 0, free = 0;
  31         int shared = 0, cached = 0, slab = 0;
  32         pg_data_t *pgdat;
  33
  34         printk("Mem-info:\n");
  35         show_free_areas();
  36
  37         for_each_online_pgdat(pgdat) {
  38                 unsigned long flags, i;
  39
  40                 pgdat_resize_lock(pgdat, &flags);
  41                 for (i = 0; i < pgdat->node_spanned_pages; i++) {
  42                         struct page *page = pgdat_page_nr(pgdat, i);
  43                         total++;
  44                         if (PageReserved(page))
  45                                 reserved++;
  46                         else if (PageSwapCache(page))
  47                                 cached++;
  48                         else if (PageSlab(page))
  49                                 slab++;
  50                         else if (!page_count(page))
  51                                 free++;
  52                         else
  53                                 shared += page_count(page) - 1;
  54                 }
  55                 pgdat_resize_unlock(pgdat, &flags);
  56         }
  57
  58         printk("Free swap:       %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
  59         printk("%d pages of RAM\n", total);
  60         printk("%d free pages\n", free);
  61         printk("%d reserved pages\n", reserved);
  62         printk("%d slab pages\n", slab);
  63         printk("%d pages shared\n", shared);
  64         printk("%d pages swap cached\n", cached);
  65         printk(KERN_INFO "Total of %ld pages in page table cache\n",
  66                quicklist_total_size());
  67 }
  68
  69 #ifdef CONFIG_MMU
  70 static void set_pte_phys(unsigned long addr, unsigned long phys, pgprot_t prot)
  71 {
  72         pgd_t *pgd;
  73         pud_t *pud;
  74         pmd_t *pmd;
  75         pte_t *pte;
  76
  77         pgd = pgd_offset_k(addr);
  78         if (pgd_none(*pgd)) {
  79                 pgd_ERROR(*pgd);
  80                 return;
  81         }
  82
  83         pud = pud_alloc(NULL, pgd, addr);
  84         if (unlikely(!pud)) {
  85                 pud_ERROR(*pud);
  86                 return;
  87         }
  88
  89         pmd = pmd_alloc(NULL, pud, addr);
  90         if (unlikely(!pmd)) {
  91                 pmd_ERROR(*pmd);
  92                 return;
  93         }
  94
  95         pte = pte_offset_kernel(pmd, addr);
  96         if (!pte_none(*pte)) {
  97                 pte_ERROR(*pte);
  98                 return;
  99         }
 100
 101         set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, prot));
 102
 103         if (cached_to_uncached)
 104                 flush_tlb_one(get_asid(), addr);
 105 }
 106
 107 /*
 108  * As a performance optimization, other platforms preserve the fixmap mapping
 109  * across a context switch, we don't presently do this, but this could be done
 110  * in a similar fashion as to the wired TLB interface that sh64 uses (by way
 111  * of the memory mapped UTLB configuration) -- this unfortunately forces us to
 112  * give up a TLB entry for each mapping we want to preserve. While this may be
 113  * viable for a small number of fixmaps, it's not particularly useful for
 114  * everything and needs to be carefully evaluated. (ie, we may want this for
 115  * the vsyscall page).
 116  *
 117  * XXX: Perhaps add a _PAGE_WIRED flag or something similar that we can pass
 118  * in at __set_fixmap() time to determine the appropriate behavior to follow.
 119  *
 120  *                                       -- PFM.
 121  */
 122 void __set_fixmap(enum fixed_addresses idx, unsigned long phys, pgprot_t prot)
 123 {
 124         unsigned long address = __fix_to_virt(idx);
 125
 126         if (idx >= __end_of_fixed_addresses) {
 127                 BUG();
 128                 return;
 129         }
 130
 131         set_pte_phys(address, phys, prot);
 132 }
 133
 134 void __init page_table_range_init(unsigned long start, unsigned long end,
 135                                          pgd_t *pgd_base)
 136 {
 137         pgd_t *pgd;
 138         pud_t *pud;
 139         pmd_t *pmd;
 140         int pgd_idx;
 141         unsigned long vaddr;
 142
 143         vaddr = start & PMD_MASK;
 144         end = (end + PMD_SIZE - 1) & PMD_MASK;
 145         pgd_idx = pgd_index(vaddr);
 146         pgd = pgd_base + pgd_idx;
 147
 148         for ( ; (pgd_idx < PTRS_PER_PGD) && (vaddr != end); pgd++, pgd_idx++) {
 149                 BUG_ON(pgd_none(*pgd));
 150                 pud = pud_offset(pgd, 0);
 151                 BUG_ON(pud_none(*pud));
 152                 pmd = pmd_offset(pud, 0);
 153
 154                 if (!pmd_present(*pmd)) {
 155                         pte_t *pte_table;
 156                         pte_table = (pte_t *)alloc_bootmem_low_pages(PAGE_SIZE);
 157                         memset(pte_table, 0, PAGE_SIZE);
 158                         pmd_populate_kernel(&init_mm, pmd, pte_table);
 159                 }
 160
 161                 vaddr += PMD_SIZE;
 162         }
 163 }
 164 #endif  /* CONFIG_MMU */
 165
 166 /*
 167  * paging_init() sets up the page tables
 168  */
 169 void __init paging_init(void)
 170 {
 171         unsigned long max_zone_pfns[MAX_NR_ZONES];
 172         int nid;
 173
 174         /* We don't need to map the kernel through the TLB, as
 175          * it is permanatly mapped using P1. So clear the
 176          * entire pgd. */
 177         memset(swapper_pg_dir, 0, sizeof(swapper_pg_dir));
 178
 179         /* Set an initial value for the MMU.TTB so we don't have to
 180          * check for a null value. */
 181         set_TTB(swapper_pg_dir);
 182
 183         /* Populate the relevant portions of swapper_pg_dir so that
 184          * we can use the fixmap entries without calling kmalloc.
 185          * pte's will be filled in by __set_fixmap(). */
 186         page_table_range_init(FIXADDR_START, FIXADDR_TOP, swapper_pg_dir);
 187
 188         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
 189
 190         for_each_online_node(nid) {
 191                 pg_data_t *pgdat = NODE_DATA(nid);
 192                 unsigned long low, start_pfn;
 193
 194                 start_pfn = pgdat->bdata->node_boot_start >> PAGE_SHIFT;
 195                 low = pgdat->bdata->node_low_pfn;
 196
 197                 if (max_zone_pfns[ZONE_NORMAL] < low)
 198                         max_zone_pfns[ZONE_NORMAL] = low;
 199
 200                 printk("Node %u: start_pfn = 0x%lx, low = 0x%lx\n",
 201                        nid, start_pfn, low);
 202         }
 203
 204         free_area_init_nodes(max_zone_pfns);
 205
 206         /* Set up the uncached fixmap */
 207         set_fixmap_nocache(FIX_UNCACHED, __pa(&__uncached_start));
 208
 209 #ifdef CONFIG_29BIT
 210         /*
 211          * Handle trivial transitions between cached and uncached
 212          * segments, making use of the 1:1 mapping relationship in
 213          * 512MB lowmem.
 214          */
 215         cached_to_uncached = P2SEG - P1SEG;
 216 #endif
 217 }
 218
 219 static struct kcore_list kcore_mem, kcore_vmalloc;
 220 int after_bootmem = 0;
 221
 222 void __init mem_init(void)
 223 {
 224         int codesize, datasize, initsize;
 225         int nid;
 226
 227         num_physpages = 0;
 228         high_memory = NULL;
 229
 230         for_each_online_node(nid) {
 231                 pg_data_t *pgdat = NODE_DATA(nid);
 232                 unsigned long node_pages = 0;
 233                 void *node_high_memory;
 234
 235                 num_physpages += pgdat->node_present_pages;
 236
 237                 if (pgdat->node_spanned_pages)
 238                         node_pages = free_all_bootmem_node(pgdat);
 239
 240                 totalram_pages += node_pages;
 241
 242                 node_high_memory = (void *)__va((pgdat->node_start_pfn +
 243                                                  pgdat->node_spanned_pages) <<
 244                                                  PAGE_SHIFT);
 245                 if (node_high_memory > high_memory)
 246                         high_memory = node_high_memory;
 247         }
 248
 249         /* clear the zero-page */
 250         memset(empty_zero_page, 0, PAGE_SIZE);
 251         __flush_wback_region(empty_zero_page, PAGE_SIZE);
 252
 253         after_bootmem = 1;
 254
 255         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
 256         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 257         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 258
 259         kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT);
 260         kclist_add(&kcore_vmalloc, (void *)VMALLOC_START,
 261                    VMALLOC_END - VMALLOC_START);
 262
 263         printk(KERN_INFO "Memory: %luk/%luk available (%dk kernel code, "
 264                "%dk data, %dk init)\n",
 265                 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
 266                 num_physpages << (PAGE_SHIFT-10),
 267                 codesize >> 10,
 268                 datasize >> 10,
 269                 initsize >> 10);
 270
 271         p3_cache_init();
 272
 273         /* Initialize the vDSO */
 274         vsyscall_init();
 275 }
 276
 277 void free_initmem(void)
 278 {
 279         unsigned long addr;
 280
 281         addr = (unsigned long)(&__init_begin);
 282         for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
 283                 ClearPageReserved(virt_to_page(addr));
 284                 init_page_count(virt_to_page(addr));
 285                 free_page(addr);
 286                 totalram_pages++;
 287         }
 288         printk("Freeing unused kernel memory: %ldk freed\n",
 289                ((unsigned long)&__init_end -
 290                 (unsigned long)&__init_begin) >> 10);
 291 }
 292
 293 #ifdef CONFIG_BLK_DEV_INITRD
 294 void free_initrd_mem(unsigned long start, unsigned long end)
 295 {
 296         unsigned long p;
 297         for (p = start; p < end; p += PAGE_SIZE) {
 298                 ClearPageReserved(virt_to_page(p));
 299                 init_page_count(virt_to_page(p));
 300                 free_page(p);
 301                 totalram_pages++;
 302         }
 303         printk("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
 304 }
 305 #endif
 306
 307 #ifdef CONFIG_MEMORY_HOTPLUG
 308 void online_page(struct page *page)
 309 {
 310         ClearPageReserved(page);
 311         init_page_count(page);
 312         __free_page(page);
 313         totalram_pages++;
 314         num_physpages++;
 315 }
 316
 317 int arch_add_memory(int nid, u64 start, u64 size)
 318 {
 319         pg_data_t *pgdat;
 320         unsigned long start_pfn = start >> PAGE_SHIFT;
 321         unsigned long nr_pages = size >> PAGE_SHIFT;
 322         int ret;
 323
 324         pgdat = NODE_DATA(nid);
 325
 326         /* We only have ZONE_NORMAL, so this is easy.. */
 327         ret = __add_pages(pgdat->node_zones + ZONE_NORMAL, start_pfn, nr_pages);
 328         if (unlikely(ret))
 329                 printk("%s: Failed, __add_pages() == %d\n", __FUNCTION__, ret);
 330
 331         return ret;
 332 }
 333 EXPORT_SYMBOL_GPL(arch_add_memory);
 334
 335 #ifdef CONFIG_NUMA
 336 int memory_add_physaddr_to_nid(u64 addr)
 337 {
 338         /* Node 0 for now.. */
 339         return 0;
 340 }
 341 EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
 342 #endif
 343 #endif