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/cache.h>
  22
  23 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
  24 pgd_t swapper_pg_dir[PTRS_PER_PGD];
  25
  26 void (*copy_page)(void *from, void *to);
  27 void (*clear_page)(void *to);
  28
  29 void show_mem(void)
  30 {
  31         int total = 0, reserved = 0, free = 0;
  32         int shared = 0, cached = 0, slab = 0;
  33         pg_data_t *pgdat;
  34
  35         printk("Mem-info:\n");
  36         show_free_areas();
  37
  38         for_each_online_pgdat(pgdat) {
  39                 unsigned long flags, i;
  40
  41                 pgdat_resize_lock(pgdat, &flags);
  42                 for (i = 0; i < pgdat->node_spanned_pages; i++) {
  43                         struct page *page = pgdat_page_nr(pgdat, i);
  44                         total++;
  45                         if (PageReserved(page))
  46                                 reserved++;
  47                         else if (PageSwapCache(page))
  48                                 cached++;
  49                         else if (PageSlab(page))
  50                                 slab++;
  51                         else if (!page_count(page))
  52                                 free++;
  53                         else
  54                                 shared += page_count(page) - 1;
  55                 }
  56                 pgdat_resize_unlock(pgdat, &flags);
  57         }
  58
  59         printk("Free swap:       %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
  60         printk("%d pages of RAM\n", total);
  61         printk("%d free pages\n", free);
  62         printk("%d reserved pages\n", reserved);
  63         printk("%d slab pages\n", slab);
  64         printk("%d pages shared\n", shared);
  65         printk("%d pages swap cached\n", cached);
  66         printk(KERN_INFO "Total of %ld pages in page table cache\n",
  67                quicklist_total_size());
  68 }
  69
  70 #ifdef CONFIG_MMU
  71 static void set_pte_phys(unsigned long addr, unsigned long phys, pgprot_t prot)
  72 {
  73         pgd_t *pgd;
  74         pud_t *pud;
  75         pmd_t *pmd;
  76         pte_t *pte;
  77
  78         pgd = pgd_offset_k(addr);
  79         if (pgd_none(*pgd)) {
  80                 pgd_ERROR(*pgd);
  81                 return;
  82         }
  83
  84         pud = pud_alloc(NULL, pgd, addr);
  85         if (unlikely(!pud)) {
  86                 pud_ERROR(*pud);
  87                 return;
  88         }
  89
  90         pmd = pmd_alloc(NULL, pud, addr);
  91         if (unlikely(!pmd)) {
  92                 pmd_ERROR(*pmd);
  93                 return;
  94         }
  95
  96         pte = pte_offset_kernel(pmd, addr);
  97         if (!pte_none(*pte)) {
  98                 pte_ERROR(*pte);
  99                 return;
 100         }
 101
 102         set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, prot));
 103
 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 /* References to section boundaries */
 136
 137 extern char _text, _etext, _edata, __bss_start, _end;
 138 extern char __init_begin, __init_end;
 139
 140 /*
 141  * paging_init() sets up the page tables
 142  */
 143 void __init paging_init(void)
 144 {
 145         int nid;
 146
 147         /* We don't need to map the kernel through the TLB, as
 148          * it is permanatly mapped using P1. So clear the
 149          * entire pgd. */
 150         memset(swapper_pg_dir, 0, sizeof(swapper_pg_dir));
 151
 152         /* Set an initial value for the MMU.TTB so we don't have to
 153          * check for a null value. */
 154         set_TTB(swapper_pg_dir);
 155
 156         for_each_online_node(nid) {
 157                 pg_data_t *pgdat = NODE_DATA(nid);
 158                 unsigned long max_zone_pfns[MAX_NR_ZONES];
 159                 unsigned long low, start_pfn;
 160
 161                 memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
 162
 163                 start_pfn = pgdat->bdata->node_boot_start >> PAGE_SHIFT;
 164                 low = pgdat->bdata->node_low_pfn;
 165
 166                 max_zone_pfns[ZONE_NORMAL] = low;
 167
 168                 printk("Node %u: start_pfn = 0x%lx, low = 0x%lx\n",
 169                        nid, start_pfn, low);
 170
 171                 free_area_init_nodes(max_zone_pfns);
 172         }
 173 }
 174
 175 static struct kcore_list kcore_mem, kcore_vmalloc;
 176
 177 void __init mem_init(void)
 178 {
 179         int codesize, datasize, initsize;
 180         int nid;
 181
 182         for_each_online_node(nid) {
 183                 pg_data_t *pgdat = NODE_DATA(nid);
 184                 unsigned long node_pages = 0;
 185                 void *node_high_memory;
 186
 187                 num_physpages += pgdat->node_present_pages;
 188
 189                 if (pgdat->node_spanned_pages)
 190                         node_pages = free_all_bootmem_node(pgdat);
 191
 192                 totalram_pages += node_pages;
 193
 194                 node_high_memory = (void *)((pgdat->node_start_pfn +
 195                                              pgdat->node_spanned_pages) <<
 196                                                 PAGE_SHIFT);
 197                 if (node_high_memory > high_memory)
 198                         high_memory = node_high_memory;
 199         }
 200
 201         /* clear the zero-page */
 202         memset(empty_zero_page, 0, PAGE_SIZE);
 203         __flush_wback_region(empty_zero_page, PAGE_SIZE);
 204
 205         /*
 206          * Setup wrappers for copy/clear_page(), these will get overridden
 207          * later in the boot process if a better method is available.
 208          */
 209 #ifdef CONFIG_MMU
 210         copy_page = copy_page_slow;
 211         clear_page = clear_page_slow;
 212 #else
 213         copy_page = copy_page_nommu;
 214         clear_page = clear_page_nommu;
 215 #endif
 216
 217         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
 218         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 219         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 220
 221         kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT);
 222         kclist_add(&kcore_vmalloc, (void *)VMALLOC_START,
 223                    VMALLOC_END - VMALLOC_START);
 224
 225         printk(KERN_INFO "Memory: %luk/%luk available (%dk kernel code, "
 226                "%dk data, %dk init)\n",
 227                 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
 228                 totalram_pages << (PAGE_SHIFT-10),
 229                 codesize >> 10,
 230                 datasize >> 10,
 231                 initsize >> 10);
 232
 233         p3_cache_init();
 234
 235         /* Initialize the vDSO */
 236         vsyscall_init();
 237 }
 238
 239 void free_initmem(void)
 240 {
 241         unsigned long addr;
 242
 243         addr = (unsigned long)(&__init_begin);
 244         for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
 245                 ClearPageReserved(virt_to_page(addr));
 246                 init_page_count(virt_to_page(addr));
 247                 free_page(addr);
 248                 totalram_pages++;
 249         }
 250         printk ("Freeing unused kernel memory: %dk freed\n", (&__init_end - &__init_begin) >> 10);
 251 }
 252
 253 #ifdef CONFIG_BLK_DEV_INITRD
 254 void free_initrd_mem(unsigned long start, unsigned long end)
 255 {
 256         unsigned long p;
 257         for (p = start; p < end; p += PAGE_SIZE) {
 258                 ClearPageReserved(virt_to_page(p));
 259                 init_page_count(virt_to_page(p));
 260                 free_page(p);
 261                 totalram_pages++;
 262         }
 263         printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
 264 }
 265 #endif