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 #ifdef CONFIG_MMU
  29 static void set_pte_phys(unsigned long addr, unsigned long phys, pgprot_t prot)
  30 {
  31         pgd_t *pgd;
  32         pud_t *pud;
  33         pmd_t *pmd;
  34         pte_t *pte;
  35
  36         pgd = pgd_offset_k(addr);
  37         if (pgd_none(*pgd)) {
  38                 pgd_ERROR(*pgd);
  39                 return;
  40         }
  41
  42         pud = pud_alloc(NULL, pgd, addr);
  43         if (unlikely(!pud)) {
  44                 pud_ERROR(*pud);
  45                 return;
  46         }
  47
  48         pmd = pmd_alloc(NULL, pud, addr);
  49         if (unlikely(!pmd)) {
  50                 pmd_ERROR(*pmd);
  51                 return;
  52         }
  53
  54         pte = pte_offset_kernel(pmd, addr);
  55         if (!pte_none(*pte)) {
  56                 pte_ERROR(*pte);
  57                 return;
  58         }
  59
  60         set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, prot));
  61
  62         if (cached_to_uncached)
  63                 flush_tlb_one(get_asid(), addr);
  64 }
  65
  66 /*
  67  * As a performance optimization, other platforms preserve the fixmap mapping
  68  * across a context switch, we don't presently do this, but this could be done
  69  * in a similar fashion as to the wired TLB interface that sh64 uses (by way
  70  * of the memory mapped UTLB configuration) -- this unfortunately forces us to
  71  * give up a TLB entry for each mapping we want to preserve. While this may be
  72  * viable for a small number of fixmaps, it's not particularly useful for
  73  * everything and needs to be carefully evaluated. (ie, we may want this for
  74  * the vsyscall page).
  75  *
  76  * XXX: Perhaps add a _PAGE_WIRED flag or something similar that we can pass
  77  * in at __set_fixmap() time to determine the appropriate behavior to follow.
  78  *
  79  *                                       -- PFM.
  80  */
  81 void __set_fixmap(enum fixed_addresses idx, unsigned long phys, pgprot_t prot)
  82 {
  83         unsigned long address = __fix_to_virt(idx);
  84
  85         if (idx >= __end_of_fixed_addresses) {
  86                 BUG();
  87                 return;
  88         }
  89
  90         set_pte_phys(address, phys, prot);
  91 }
  92
  93 void __init page_table_range_init(unsigned long start, unsigned long end,
  94                                          pgd_t *pgd_base)
  95 {
  96         pgd_t *pgd;
  97         pud_t *pud;
  98         pmd_t *pmd;
  99         int pgd_idx;
 100         unsigned long vaddr;
 101
 102         vaddr = start & PMD_MASK;
 103         end = (end + PMD_SIZE - 1) & PMD_MASK;
 104         pgd_idx = pgd_index(vaddr);
 105         pgd = pgd_base + pgd_idx;
 106
 107         for ( ; (pgd_idx < PTRS_PER_PGD) && (vaddr != end); pgd++, pgd_idx++) {
 108                 BUG_ON(pgd_none(*pgd));
 109                 pud = pud_offset(pgd, 0);
 110                 BUG_ON(pud_none(*pud));
 111                 pmd = pmd_offset(pud, 0);
 112
 113                 if (!pmd_present(*pmd)) {
 114                         pte_t *pte_table;
 115                         pte_table = (pte_t *)alloc_bootmem_low_pages(PAGE_SIZE);
 116                         memset(pte_table, 0, PAGE_SIZE);
 117                         pmd_populate_kernel(&init_mm, pmd, pte_table);
 118                 }
 119
 120                 vaddr += PMD_SIZE;
 121         }
 122 }
 123 #endif  /* CONFIG_MMU */
 124
 125 /*
 126  * paging_init() sets up the page tables
 127  */
 128 void __init paging_init(void)
 129 {
 130         unsigned long max_zone_pfns[MAX_NR_ZONES];
 131         int nid;
 132
 133         /* We don't need to map the kernel through the TLB, as
 134          * it is permanatly mapped using P1. So clear the
 135          * entire pgd. */
 136         memset(swapper_pg_dir, 0, sizeof(swapper_pg_dir));
 137
 138         /* Set an initial value for the MMU.TTB so we don't have to
 139          * check for a null value. */
 140         set_TTB(swapper_pg_dir);
 141
 142         /* Populate the relevant portions of swapper_pg_dir so that
 143          * we can use the fixmap entries without calling kmalloc.
 144          * pte's will be filled in by __set_fixmap(). */
 145         page_table_range_init(FIXADDR_START, FIXADDR_TOP, swapper_pg_dir);
 146
 147         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
 148
 149         for_each_online_node(nid) {
 150                 pg_data_t *pgdat = NODE_DATA(nid);
 151                 unsigned long low, start_pfn;
 152
 153                 start_pfn = pgdat->bdata->node_min_pfn;
 154                 low = pgdat->bdata->node_low_pfn;
 155
 156                 if (max_zone_pfns[ZONE_NORMAL] < low)
 157                         max_zone_pfns[ZONE_NORMAL] = low;
 158
 159                 printk("Node %u: start_pfn = 0x%lx, low = 0x%lx\n",
 160                        nid, start_pfn, low);
 161         }
 162
 163         free_area_init_nodes(max_zone_pfns);
 164
 165 #ifdef CONFIG_SUPERH32
 166         /* Set up the uncached fixmap */
 167         set_fixmap_nocache(FIX_UNCACHED, __pa(&__uncached_start));
 168
 169 #ifdef CONFIG_29BIT
 170         /*
 171          * Handle trivial transitions between cached and uncached
 172          * segments, making use of the 1:1 mapping relationship in
 173          * 512MB lowmem.
 174          */
 175         cached_to_uncached = P2SEG - P1SEG;
 176 #endif
 177 #endif
 178 }
 179
 180 static struct kcore_list kcore_mem, kcore_vmalloc;
 181 int after_bootmem = 0;
 182
 183 void __init mem_init(void)
 184 {
 185         int codesize, datasize, initsize;
 186         int nid;
 187
 188         num_physpages = 0;
 189         high_memory = NULL;
 190
 191         for_each_online_node(nid) {
 192                 pg_data_t *pgdat = NODE_DATA(nid);
 193                 unsigned long node_pages = 0;
 194                 void *node_high_memory;
 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                 node_high_memory = (void *)__va((pgdat->node_start_pfn +
 204                                                  pgdat->node_spanned_pages) <<
 205                                                  PAGE_SHIFT);
 206                 if (node_high_memory > high_memory)
 207                         high_memory = node_high_memory;
 208         }
 209
 210         /* clear the zero-page */
 211         memset(empty_zero_page, 0, PAGE_SIZE);
 212         __flush_wback_region(empty_zero_page, PAGE_SIZE);
 213
 214         after_bootmem = 1;
 215
 216         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
 217         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 218         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 219
 220         kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT);
 221         kclist_add(&kcore_vmalloc, (void *)VMALLOC_START,
 222                    VMALLOC_END - VMALLOC_START);
 223
 224         printk(KERN_INFO "Memory: %luk/%luk available (%dk kernel code, "
 225                "%dk data, %dk init)\n",
 226                 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
 227                 num_physpages << (PAGE_SHIFT-10),
 228                 codesize >> 10,
 229                 datasize >> 10,
 230                 initsize >> 10);
 231
 232         p3_cache_init();
 233
 234         /* Initialize the vDSO */
 235         vsyscall_init();
 236 }
 237
 238 void free_initmem(void)
 239 {
 240         unsigned long addr;
 241
 242         addr = (unsigned long)(&__init_begin);
 243         for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
 244                 ClearPageReserved(virt_to_page(addr));
 245                 init_page_count(virt_to_page(addr));
 246                 free_page(addr);
 247                 totalram_pages++;
 248         }
 249         printk("Freeing unused kernel memory: %ldk freed\n",
 250                ((unsigned long)&__init_end -
 251                 (unsigned long)&__init_begin) >> 10);
 252 }
 253
 254 #ifdef CONFIG_BLK_DEV_INITRD
 255 void free_initrd_mem(unsigned long start, unsigned long end)
 256 {
 257         unsigned long p;
 258         for (p = start; p < end; p += PAGE_SIZE) {
 259                 ClearPageReserved(virt_to_page(p));
 260                 init_page_count(virt_to_page(p));
 261                 free_page(p);
 262                 totalram_pages++;
 263         }
 264         printk("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
 265 }
 266 #endif
 267
 268 #ifdef CONFIG_MEMORY_HOTPLUG
 269 int arch_add_memory(int nid, u64 start, u64 size)
 270 {
 271         pg_data_t *pgdat;
 272         unsigned long start_pfn = start >> PAGE_SHIFT;
 273         unsigned long nr_pages = size >> PAGE_SHIFT;
 274         int ret;
 275
 276         pgdat = NODE_DATA(nid);
 277
 278         /* We only have ZONE_NORMAL, so this is easy.. */
 279         ret = __add_pages(pgdat->node_zones + ZONE_NORMAL, start_pfn, nr_pages);
 280         if (unlikely(ret))
 281                 printk("%s: Failed, __add_pages() == %d\n", __func__, ret);
 282
 283         return ret;
 284 }
 285 EXPORT_SYMBOL_GPL(arch_add_memory);
 286
 287 #ifdef CONFIG_NUMA
 288 int memory_add_physaddr_to_nid(u64 addr)
 289 {
 290         /* Node 0 for now.. */
 291         return 0;
 292 }
 293 EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
 294 #endif
 295 #endif