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   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 #endif  /* CONFIG_MMU */
 134
 135 /*
 136  * paging_init() sets up the page tables
 137  */
 138 void __init paging_init(void)
 139 {
 140         unsigned long max_zone_pfns[MAX_NR_ZONES];
 141         int nid;
 142
 143         /* We don't need to map the kernel through the TLB, as
 144          * it is permanatly mapped using P1. So clear the
 145          * entire pgd. */
 146         memset(swapper_pg_dir, 0, sizeof(swapper_pg_dir));
 147
 148         /* Set an initial value for the MMU.TTB so we don't have to
 149          * check for a null value. */
 150         set_TTB(swapper_pg_dir);
 151
 152         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
 153
 154         for_each_online_node(nid) {
 155                 pg_data_t *pgdat = NODE_DATA(nid);
 156                 unsigned long low, start_pfn;
 157
 158                 start_pfn = pgdat->bdata->node_boot_start >> PAGE_SHIFT;
 159                 low = pgdat->bdata->node_low_pfn;
 160
 161                 if (max_zone_pfns[ZONE_NORMAL] < low)
 162                         max_zone_pfns[ZONE_NORMAL] = low;
 163
 164                 printk("Node %u: start_pfn = 0x%lx, low = 0x%lx\n",
 165                        nid, start_pfn, low);
 166         }
 167
 168         free_area_init_nodes(max_zone_pfns);
 169
 170         /* Set up the uncached fixmap */
 171         set_fixmap_nocache(FIX_UNCACHED, __pa(&__uncached_start));
 172
 173 #ifdef CONFIG_29BIT
 174         /*
 175          * Handle trivial transitions between cached and uncached
 176          * segments, making use of the 1:1 mapping relationship in
 177          * 512MB lowmem.
 178          */
 179         cached_to_uncached = P2SEG - P1SEG;
 180 #endif
 181 }
 182
 183 static struct kcore_list kcore_mem, kcore_vmalloc;
 184 int after_bootmem = 0;
 185
 186 void __init mem_init(void)
 187 {
 188         int codesize, datasize, initsize;
 189         int nid;
 190
 191         num_physpages = 0;
 192         high_memory = NULL;
 193
 194         for_each_online_node(nid) {
 195                 pg_data_t *pgdat = NODE_DATA(nid);
 196                 unsigned long node_pages = 0;
 197                 void *node_high_memory;
 198
 199                 num_physpages += pgdat->node_present_pages;
 200
 201                 if (pgdat->node_spanned_pages)
 202                         node_pages = free_all_bootmem_node(pgdat);
 203
 204                 totalram_pages += node_pages;
 205
 206                 node_high_memory = (void *)__va((pgdat->node_start_pfn +
 207                                                  pgdat->node_spanned_pages) <<
 208                                                  PAGE_SHIFT);
 209                 if (node_high_memory > high_memory)
 210                         high_memory = node_high_memory;
 211         }
 212
 213         /* clear the zero-page */
 214         memset(empty_zero_page, 0, PAGE_SIZE);
 215         __flush_wback_region(empty_zero_page, PAGE_SIZE);
 216
 217         after_bootmem = 1;
 218
 219         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
 220         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 221         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 222
 223         kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT);
 224         kclist_add(&kcore_vmalloc, (void *)VMALLOC_START,
 225                    VMALLOC_END - VMALLOC_START);
 226
 227         printk(KERN_INFO "Memory: %luk/%luk available (%dk kernel code, "
 228                "%dk data, %dk init)\n",
 229                 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
 230                 num_physpages << (PAGE_SHIFT-10),
 231                 codesize >> 10,
 232                 datasize >> 10,
 233                 initsize >> 10);
 234
 235         p3_cache_init();
 236
 237         /* Initialize the vDSO */
 238         vsyscall_init();
 239 }
 240
 241 void free_initmem(void)
 242 {
 243         unsigned long addr;
 244
 245         addr = (unsigned long)(&__init_begin);
 246         for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
 247                 ClearPageReserved(virt_to_page(addr));
 248                 init_page_count(virt_to_page(addr));
 249                 free_page(addr);
 250                 totalram_pages++;
 251         }
 252         printk("Freeing unused kernel memory: %ldk freed\n",
 253                ((unsigned long)&__init_end -
 254                 (unsigned long)&__init_begin) >> 10);
 255 }
 256
 257 #ifdef CONFIG_BLK_DEV_INITRD
 258 void free_initrd_mem(unsigned long start, unsigned long end)
 259 {
 260         unsigned long p;
 261         for (p = start; p < end; p += PAGE_SIZE) {
 262                 ClearPageReserved(virt_to_page(p));
 263                 init_page_count(virt_to_page(p));
 264                 free_page(p);
 265                 totalram_pages++;
 266         }
 267         printk("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
 268 }
 269 #endif
 270
 271 #ifdef CONFIG_MEMORY_HOTPLUG
 272 void online_page(struct page *page)
 273 {
 274         ClearPageReserved(page);
 275         init_page_count(page);
 276         __free_page(page);
 277         totalram_pages++;
 278         num_physpages++;
 279 }
 280
 281 int arch_add_memory(int nid, u64 start, u64 size)
 282 {
 283         pg_data_t *pgdat;
 284         unsigned long start_pfn = start >> PAGE_SHIFT;
 285         unsigned long nr_pages = size >> PAGE_SHIFT;
 286         int ret;
 287
 288         pgdat = NODE_DATA(nid);
 289
 290         /* We only have ZONE_NORMAL, so this is easy.. */
 291         ret = __add_pages(pgdat->node_zones + ZONE_NORMAL, start_pfn, nr_pages);
 292         if (unlikely(ret))
 293                 printk("%s: Failed, __add_pages() == %d\n", __FUNCTION__, ret);
 294
 295         return ret;
 296 }
 297 EXPORT_SYMBOL_GPL(arch_add_memory);
 298
 299 #ifdef CONFIG_NUMA
 300 int memory_add_physaddr_to_nid(u64 addr)
 301 {
 302         /* Node 0 for now.. */
 303         return 0;
 304 }
 305 EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
 306 #endif
 307 #endif