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/percpu.h>
  16 #include <linux/io.h>
  17 #include <asm/mmu_context.h>
  18 #include <asm/tlb.h>
  19 #include <asm/cacheflush.h>
  20 #include <asm/cache.h>
  21
  22 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
  23 pgd_t swapper_pg_dir[PTRS_PER_PGD];
  24
  25 void (*copy_page)(void *from, void *to);
  26 void (*clear_page)(void *to);
  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                 struct page *page, *end;
  39                 unsigned long flags;
  40
  41                 pgdat_resize_lock(pgdat, &flags);
  42                 page = pgdat->node_mem_map;
  43                 end = page + pgdat->node_spanned_pages;
  44
  45                 do {
  46                         total++;
  47                         if (PageReserved(page))
  48                                 reserved++;
  49                         else if (PageSwapCache(page))
  50                                 cached++;
  51                         else if (PageSlab(page))
  52                                 slab++;
  53                         else if (!page_count(page))
  54                                 free++;
  55                         else
  56                                 shared += page_count(page) - 1;
  57                         page++;
  58                 } while (page < end);
  59
  60                 pgdat_resize_unlock(pgdat, &flags);
  61         }
  62
  63         printk("Free swap:       %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
  64         printk("%d pages of RAM\n", total);
  65         printk("%d free pages\n", free);
  66         printk("%d reserved pages\n", reserved);
  67         printk("%d slab pages\n", slab);
  68         printk("%d pages shared\n", shared);
  69         printk("%d pages swap cached\n", cached);
  70 }
  71
  72 #ifdef CONFIG_MMU
  73 static void set_pte_phys(unsigned long addr, unsigned long phys, pgprot_t prot)
  74 {
  75         pgd_t *pgd;
  76         pud_t *pud;
  77         pmd_t *pmd;
  78         pte_t *pte;
  79
  80         pgd = pgd_offset_k(addr);
  81         if (pgd_none(*pgd)) {
  82                 pgd_ERROR(*pgd);
  83                 return;
  84         }
  85
  86         pud = pud_alloc(NULL, pgd, addr);
  87         if (unlikely(!pud)) {
  88                 pud_ERROR(*pud);
  89                 return;
  90         }
  91
  92         pmd = pmd_alloc(NULL, pud, addr);
  93         if (unlikely(!pmd)) {
  94                 pmd_ERROR(*pmd);
  95                 return;
  96         }
  97
  98         pte = pte_offset_kernel(pmd, addr);
  99         if (!pte_none(*pte)) {
 100                 pte_ERROR(*pte);
 101                 return;
 102         }
 103
 104         set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, prot));
 105
 106         flush_tlb_one(get_asid(), addr);
 107 }
 108
 109 /*
 110  * As a performance optimization, other platforms preserve the fixmap mapping
 111  * across a context switch, we don't presently do this, but this could be done
 112  * in a similar fashion as to the wired TLB interface that sh64 uses (by way
 113  * of the memorry mapped UTLB configuration) -- this unfortunately forces us to
 114  * give up a TLB entry for each mapping we want to preserve. While this may be
 115  * viable for a small number of fixmaps, it's not particularly useful for
 116  * everything and needs to be carefully evaluated. (ie, we may want this for
 117  * the vsyscall page).
 118  *
 119  * XXX: Perhaps add a _PAGE_WIRED flag or something similar that we can pass
 120  * in at __set_fixmap() time to determine the appropriate behavior to follow.
 121  *
 122  *                                       -- PFM.
 123  */
 124 void __set_fixmap(enum fixed_addresses idx, unsigned long phys, pgprot_t prot)
 125 {
 126         unsigned long address = __fix_to_virt(idx);
 127
 128         if (idx >= __end_of_fixed_addresses) {
 129                 BUG();
 130                 return;
 131         }
 132
 133         set_pte_phys(address, phys, prot);
 134 }
 135 #endif  /* CONFIG_MMU */
 136
 137 /* References to section boundaries */
 138
 139 extern char _text, _etext, _edata, __bss_start, _end;
 140 extern char __init_begin, __init_end;
 141
 142 /*
 143  * paging_init() sets up the page tables
 144  */
 145 void __init paging_init(void)
 146 {
 147         int nid;
 148
 149         /* We don't need to map the kernel through the TLB, as
 150          * it is permanatly mapped using P1. So clear the
 151          * entire pgd. */
 152         memset(swapper_pg_dir, 0, sizeof(swapper_pg_dir));
 153
 154         /* Set an initial value for the MMU.TTB so we don't have to
 155          * check for a null value. */
 156         set_TTB(swapper_pg_dir);
 157
 158         for_each_online_node(nid) {
 159                 pg_data_t *pgdat = NODE_DATA(nid);
 160                 unsigned long max_zone_pfns[MAX_NR_ZONES];
 161                 unsigned long low, start_pfn;
 162
 163                 memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
 164
 165                 start_pfn = pgdat->bdata->node_boot_start >> PAGE_SHIFT;
 166                 low = pgdat->bdata->node_low_pfn;
 167
 168                 max_zone_pfns[ZONE_NORMAL] = low;
 169                 add_active_range(nid, start_pfn, low);
 170
 171                 printk("Node %u: start_pfn = 0x%lx, low = 0x%lx\n",
 172                        nid, start_pfn, low);
 173
 174                 free_area_init_nodes(max_zone_pfns);
 175
 176                 printk("Node %u: mem_map starts at %p\n",
 177                        pgdat->node_id, pgdat->node_mem_map);
 178         }
 179 }
 180
 181 static struct kcore_list kcore_mem, kcore_vmalloc;
 182
 183 void __init mem_init(void)
 184 {
 185         int codesize, reservedpages, datasize, initsize;
 186         int nid;
 187
 188         reservedpages = 0;
 189
 190         for_each_online_node(nid) {
 191                 pg_data_t *pgdat = NODE_DATA(nid);
 192                 unsigned long node_pages = 0;
 193                 void *node_high_memory;
 194                 int i;
 195
 196                 num_physpages += pgdat->node_present_pages;
 197
 198                 if (pgdat->node_spanned_pages)
 199                         node_pages = free_all_bootmem_node(pgdat);
 200
 201                 totalram_pages += node_pages;
 202
 203                 for (i = 0; i < node_pages; i++)
 204                         if (PageReserved(pgdat->node_mem_map + i))
 205                                 reservedpages++;
 206
 207                 node_high_memory = (void *)((pgdat->node_start_pfn +
 208                                              pgdat->node_spanned_pages) <<
 209                                                 PAGE_SHIFT);
 210                 if (node_high_memory > high_memory)
 211                         high_memory = node_high_memory;
 212         }
 213
 214         /* clear the zero-page */
 215         memset(empty_zero_page, 0, PAGE_SIZE);
 216         __flush_wback_region(empty_zero_page, PAGE_SIZE);
 217
 218         /*
 219          * Setup wrappers for copy/clear_page(), these will get overridden
 220          * later in the boot process if a better method is available.
 221          */
 222 #ifdef CONFIG_MMU
 223         copy_page = copy_page_slow;
 224         clear_page = clear_page_slow;
 225 #else
 226         copy_page = copy_page_nommu;
 227         clear_page = clear_page_nommu;
 228 #endif
 229
 230         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
 231         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 232         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 233
 234         kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT);
 235         kclist_add(&kcore_vmalloc, (void *)VMALLOC_START,
 236                    VMALLOC_END - VMALLOC_START);
 237
 238         printk(KERN_INFO "Memory: %luk/%luk available (%dk kernel code, "
 239                "%dk reserved, %dk data, %dk init)\n",
 240                 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
 241                 totalram_pages << (PAGE_SHIFT-10),
 242                 codesize >> 10,
 243                 reservedpages << (PAGE_SHIFT-10),
 244                 datasize >> 10,
 245                 initsize >> 10);
 246
 247         p3_cache_init();
 248
 249         /* Initialize the vDSO */
 250         vsyscall_init();
 251 }
 252
 253 void free_initmem(void)
 254 {
 255         unsigned long addr;
 256
 257         addr = (unsigned long)(&__init_begin);
 258         for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
 259                 ClearPageReserved(virt_to_page(addr));
 260                 init_page_count(virt_to_page(addr));
 261                 free_page(addr);
 262                 totalram_pages++;
 263         }
 264         printk ("Freeing unused kernel memory: %dk freed\n", (&__init_end - &__init_begin) >> 10);
 265 }
 266
 267 #ifdef CONFIG_BLK_DEV_INITRD
 268 void free_initrd_mem(unsigned long start, unsigned long end)
 269 {
 270         unsigned long p;
 271         for (p = start; p < end; p += PAGE_SIZE) {
 272                 ClearPageReserved(virt_to_page(p));
 273                 init_page_count(virt_to_page(p));
 274                 free_page(p);
 275                 totalram_pages++;
 276         }
 277         printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
 278 }
 279 #endif