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
  27 #ifdef CONFIG_SUPERH32
  28 /*
  29  * Handle trivial transitions between cached and uncached
  30  * segments, making use of the 1:1 mapping relationship in
  31  * 512MB lowmem.
  32  *
  33  * This is the offset of the uncached section from its cached alias.
  34  * Default value only valid in 29 bit mode, in 32bit mode will be
  35  * overridden in pmb_init.
  36  */
  37 unsigned long cached_to_uncached = P2SEG - P1SEG;
  38 #endif
  39
  40 #ifdef CONFIG_MMU
  41 static void set_pte_phys(unsigned long addr, unsigned long phys, pgprot_t prot)
  42 {
  43         pgd_t *pgd;
  44         pud_t *pud;
  45         pmd_t *pmd;
  46         pte_t *pte;
  47
  48         pgd = pgd_offset_k(addr);
  49         if (pgd_none(*pgd)) {
  50                 pgd_ERROR(*pgd);
  51                 return;
  52         }
  53
  54         pud = pud_alloc(NULL, pgd, addr);
  55         if (unlikely(!pud)) {
  56                 pud_ERROR(*pud);
  57                 return;
  58         }
  59
  60         pmd = pmd_alloc(NULL, pud, addr);
  61         if (unlikely(!pmd)) {
  62                 pmd_ERROR(*pmd);
  63                 return;
  64         }
  65
  66         pte = pte_offset_kernel(pmd, addr);
  67         if (!pte_none(*pte)) {
  68                 pte_ERROR(*pte);
  69                 return;
  70         }
  71
  72         set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, prot));
  73         flush_tlb_one(get_asid(), addr);
  74 }
  75
  76 /*
  77  * As a performance optimization, other platforms preserve the fixmap mapping
  78  * across a context switch, we don't presently do this, but this could be done
  79  * in a similar fashion as to the wired TLB interface that sh64 uses (by way
  80  * of the memory mapped UTLB configuration) -- this unfortunately forces us to
  81  * give up a TLB entry for each mapping we want to preserve. While this may be
  82  * viable for a small number of fixmaps, it's not particularly useful for
  83  * everything and needs to be carefully evaluated. (ie, we may want this for
  84  * the vsyscall page).
  85  *
  86  * XXX: Perhaps add a _PAGE_WIRED flag or something similar that we can pass
  87  * in at __set_fixmap() time to determine the appropriate behavior to follow.
  88  *
  89  *                                       -- PFM.
  90  */
  91 void __set_fixmap(enum fixed_addresses idx, unsigned long phys, pgprot_t prot)
  92 {
  93         unsigned long address = __fix_to_virt(idx);
  94
  95         if (idx >= __end_of_fixed_addresses) {
  96                 BUG();
  97                 return;
  98         }
  99
 100         set_pte_phys(address, phys, prot);
 101 }
 102
 103 void __init page_table_range_init(unsigned long start, unsigned long end,
 104                                          pgd_t *pgd_base)
 105 {
 106         pgd_t *pgd;
 107         pud_t *pud;
 108         pmd_t *pmd;
 109         int pgd_idx;
 110         unsigned long vaddr;
 111
 112         vaddr = start & PMD_MASK;
 113         end = (end + PMD_SIZE - 1) & PMD_MASK;
 114         pgd_idx = pgd_index(vaddr);
 115         pgd = pgd_base + pgd_idx;
 116
 117         for ( ; (pgd_idx < PTRS_PER_PGD) && (vaddr != end); pgd++, pgd_idx++) {
 118                 BUG_ON(pgd_none(*pgd));
 119                 pud = pud_offset(pgd, 0);
 120                 BUG_ON(pud_none(*pud));
 121                 pmd = pmd_offset(pud, 0);
 122
 123                 if (!pmd_present(*pmd)) {
 124                         pte_t *pte_table;
 125                         pte_table = (pte_t *)alloc_bootmem_low_pages(PAGE_SIZE);
 126                         pmd_populate_kernel(&init_mm, pmd, pte_table);
 127                 }
 128
 129                 vaddr += PMD_SIZE;
 130         }
 131 }
 132 #endif  /* CONFIG_MMU */
 133
 134 /*
 135  * paging_init() sets up the page tables
 136  */
 137 void __init paging_init(void)
 138 {
 139         unsigned long max_zone_pfns[MAX_NR_ZONES];
 140         int nid;
 141
 142         /* We don't need to map the kernel through the TLB, as
 143          * it is permanatly mapped using P1. So clear the
 144          * entire pgd. */
 145         memset(swapper_pg_dir, 0, sizeof(swapper_pg_dir));
 146
 147         /* Set an initial value for the MMU.TTB so we don't have to
 148          * check for a null value. */
 149         set_TTB(swapper_pg_dir);
 150
 151         /* Populate the relevant portions of swapper_pg_dir so that
 152          * we can use the fixmap entries without calling kmalloc.
 153          * pte's will be filled in by __set_fixmap(). */
 154         page_table_range_init(FIXADDR_START, FIXADDR_TOP, swapper_pg_dir);
 155
 156         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
 157
 158         for_each_online_node(nid) {
 159                 pg_data_t *pgdat = NODE_DATA(nid);
 160                 unsigned long low, start_pfn;
 161
 162                 start_pfn = pgdat->bdata->node_min_pfn;
 163                 low = pgdat->bdata->node_low_pfn;
 164
 165                 if (max_zone_pfns[ZONE_NORMAL] < low)
 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
 172         free_area_init_nodes(max_zone_pfns);
 173
 174 #ifdef CONFIG_SUPERH32
 175         /* Set up the uncached fixmap */
 176         set_fixmap_nocache(FIX_UNCACHED, __pa(&__uncached_start));
 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 #if THREAD_SHIFT < PAGE_SHIFT
 269 static struct kmem_cache *thread_info_cache;
 270
 271 struct thread_info *alloc_thread_info(struct task_struct *tsk)
 272 {
 273         struct thread_info *ti;
 274
 275         ti = kmem_cache_alloc(thread_info_cache, GFP_KERNEL);
 276         if (unlikely(ti == NULL))
 277                 return NULL;
 278 #ifdef CONFIG_DEBUG_STACK_USAGE
 279         memset(ti, 0, THREAD_SIZE);
 280 #endif
 281         return ti;
 282 }
 283
 284 void free_thread_info(struct thread_info *ti)
 285 {
 286         kmem_cache_free(thread_info_cache, ti);
 287 }
 288
 289 void thread_info_cache_init(void)
 290 {
 291         thread_info_cache = kmem_cache_create("thread_info", THREAD_SIZE,
 292                                               THREAD_SIZE, 0, NULL);
 293         BUG_ON(thread_info_cache == NULL);
 294 }
 295 #endif /* THREAD_SHIFT < PAGE_SHIFT */
 296
 297 #ifdef CONFIG_MEMORY_HOTPLUG
 298 int arch_add_memory(int nid, u64 start, u64 size)
 299 {
 300         pg_data_t *pgdat;
 301         unsigned long start_pfn = start >> PAGE_SHIFT;
 302         unsigned long nr_pages = size >> PAGE_SHIFT;
 303         int ret;
 304
 305         pgdat = NODE_DATA(nid);
 306
 307         /* We only have ZONE_NORMAL, so this is easy.. */
 308         ret = __add_pages(pgdat->node_zones + ZONE_NORMAL, start_pfn, nr_pages);
 309         if (unlikely(ret))
 310                 printk("%s: Failed, __add_pages() == %d\n", __func__, ret);
 311
 312         return ret;
 313 }
 314 EXPORT_SYMBOL_GPL(arch_add_memory);
 315
 316 #ifdef CONFIG_NUMA
 317 int memory_add_physaddr_to_nid(u64 addr)
 318 {
 319         /* Node 0 for now.. */
 320         return 0;
 321 }
 322 EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
 323 #endif
 324
 325 #ifdef CONFIG_MEMORY_HOTREMOVE
 326 int remove_memory(u64 start, u64 size)
 327 {
 328         unsigned long start_pfn = start >> PAGE_SHIFT;
 329         unsigned long end_pfn = start_pfn + (size >> PAGE_SHIFT);
 330         int ret;
 331
 332         ret = offline_pages(start_pfn, end_pfn, 120 * HZ);
 333         if (unlikely(ret))
 334                 printk("%s: Failed, offline_pages() == %d\n", __func__, ret);
 335
 336         return ret;
 337 }
 338 EXPORT_SYMBOL_GPL(remove_memory);
 339 #endif
 340
 341 #endif /* CONFIG_MEMORY_HOTPLUG */