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         local_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         pte_t *pte;
 110         int i, j, k;
 111         unsigned long vaddr;
 112
 113         vaddr = start;
 114         i = __pgd_offset(vaddr);
 115         j = __pud_offset(vaddr);
 116         k = __pmd_offset(vaddr);
 117         pgd = pgd_base + i;
 118
 119         for ( ; (i < PTRS_PER_PGD) && (vaddr != end); pgd++, i++) {
 120                 pud = (pud_t *)pgd;
 121                 for ( ; (j < PTRS_PER_PUD) && (vaddr != end); pud++, j++) {
 122                         pmd = (pmd_t *)pud;
 123                         for (; (k < PTRS_PER_PMD) && (vaddr != end); pmd++, k++) {
 124                                 if (pmd_none(*pmd)) {
 125                                         pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
 126                                         pmd_populate_kernel(&init_mm, pmd, pte);
 127                                         BUG_ON(pte != pte_offset_kernel(pmd, 0));
 128                                 }
 129                                 vaddr += PMD_SIZE;
 130                         }
 131                         k = 0;
 132                 }
 133                 j = 0;
 134         }
 135 }
 136 #endif  /* CONFIG_MMU */
 137
 138 /*
 139  * paging_init() sets up the page tables
 140  */
 141 void __init paging_init(void)
 142 {
 143         unsigned long max_zone_pfns[MAX_NR_ZONES];
 144         unsigned long vaddr, end;
 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         /*
 157          * Populate the relevant portions of swapper_pg_dir so that
 158          * we can use the fixmap entries without calling kmalloc.
 159          * pte's will be filled in by __set_fixmap().
 160          */
 161         vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
 162         end = (FIXADDR_TOP + PMD_SIZE - 1) & PMD_MASK;
 163         page_table_range_init(vaddr, end, swapper_pg_dir);
 164
 165         kmap_coherent_init();
 166
 167         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
 168
 169         for_each_online_node(nid) {
 170                 pg_data_t *pgdat = NODE_DATA(nid);
 171                 unsigned long low, start_pfn;
 172
 173                 start_pfn = pgdat->bdata->node_min_pfn;
 174                 low = pgdat->bdata->node_low_pfn;
 175
 176                 if (max_zone_pfns[ZONE_NORMAL] < low)
 177                         max_zone_pfns[ZONE_NORMAL] = low;
 178
 179                 printk("Node %u: start_pfn = 0x%lx, low = 0x%lx\n",
 180                        nid, start_pfn, low);
 181         }
 182
 183         free_area_init_nodes(max_zone_pfns);
 184
 185         /* Set up the uncached fixmap */
 186         set_fixmap_nocache(FIX_UNCACHED, __pa(&__uncached_start));
 187 }
 188
 189 void __init mem_init(void)
 190 {
 191         int codesize, datasize, initsize;
 192         int nid;
 193
 194         num_physpages = 0;
 195         high_memory = NULL;
 196
 197         for_each_online_node(nid) {
 198                 pg_data_t *pgdat = NODE_DATA(nid);
 199                 unsigned long node_pages = 0;
 200                 void *node_high_memory;
 201
 202                 num_physpages += pgdat->node_present_pages;
 203
 204                 if (pgdat->node_spanned_pages)
 205                         node_pages = free_all_bootmem_node(pgdat);
 206
 207                 totalram_pages += node_pages;
 208
 209                 node_high_memory = (void *)__va((pgdat->node_start_pfn +
 210                                                  pgdat->node_spanned_pages) <<
 211                                                  PAGE_SHIFT);
 212                 if (node_high_memory > high_memory)
 213                         high_memory = node_high_memory;
 214         }
 215
 216         /* Set this up early, so we can take care of the zero page */
 217         cpu_cache_init();
 218
 219         /* clear the zero-page */
 220         memset(empty_zero_page, 0, PAGE_SIZE);
 221         __flush_wback_region(empty_zero_page, PAGE_SIZE);
 222
 223         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
 224         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 225         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 226
 227         printk(KERN_INFO "Memory: %luk/%luk available (%dk kernel code, "
 228                "%dk data, %dk init)\n",
 229                 nr_free_pages() << (PAGE_SHIFT-10),
 230                 num_physpages << (PAGE_SHIFT-10),
 231                 codesize >> 10,
 232                 datasize >> 10,
 233                 initsize >> 10);
 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: %ldk freed\n",
 251                ((unsigned long)&__init_end -
 252                 (unsigned long)&__init_begin) >> 10);
 253 }
 254
 255 #ifdef CONFIG_BLK_DEV_INITRD
 256 void free_initrd_mem(unsigned long start, unsigned long end)
 257 {
 258         unsigned long p;
 259         for (p = start; p < end; p += PAGE_SIZE) {
 260                 ClearPageReserved(virt_to_page(p));
 261                 init_page_count(virt_to_page(p));
 262                 free_page(p);
 263                 totalram_pages++;
 264         }
 265         printk("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
 266 }
 267 #endif
 268
 269 #if THREAD_SHIFT < PAGE_SHIFT
 270 static struct kmem_cache *thread_info_cache;
 271
 272 struct thread_info *alloc_thread_info(struct task_struct *tsk)
 273 {
 274         struct thread_info *ti;
 275
 276         ti = kmem_cache_alloc(thread_info_cache, GFP_KERNEL);
 277         if (unlikely(ti == NULL))
 278                 return NULL;
 279 #ifdef CONFIG_DEBUG_STACK_USAGE
 280         memset(ti, 0, THREAD_SIZE);
 281 #endif
 282         return ti;
 283 }
 284
 285 void free_thread_info(struct thread_info *ti)
 286 {
 287         kmem_cache_free(thread_info_cache, ti);
 288 }
 289
 290 void thread_info_cache_init(void)
 291 {
 292         thread_info_cache = kmem_cache_create("thread_info", THREAD_SIZE,
 293                                               THREAD_SIZE, 0, NULL);
 294         BUG_ON(thread_info_cache == NULL);
 295 }
 296 #endif /* THREAD_SHIFT < PAGE_SHIFT */
 297
 298 #ifdef CONFIG_MEMORY_HOTPLUG
 299 int arch_add_memory(int nid, u64 start, u64 size)
 300 {
 301         pg_data_t *pgdat;
 302         unsigned long start_pfn = start >> PAGE_SHIFT;
 303         unsigned long nr_pages = size >> PAGE_SHIFT;
 304         int ret;
 305
 306         pgdat = NODE_DATA(nid);
 307
 308         /* We only have ZONE_NORMAL, so this is easy.. */
 309         ret = __add_pages(nid, pgdat->node_zones + ZONE_NORMAL,
 310                                 start_pfn, nr_pages);
 311         if (unlikely(ret))
 312                 printk("%s: Failed, __add_pages() == %d\n", __func__, ret);
 313
 314         return ret;
 315 }
 316 EXPORT_SYMBOL_GPL(arch_add_memory);
 317
 318 #ifdef CONFIG_NUMA
 319 int memory_add_physaddr_to_nid(u64 addr)
 320 {
 321         /* Node 0 for now.. */
 322         return 0;
 323 }
 324 EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
 325 #endif
 326 #endif /* CONFIG_MEMORY_HOTPLUG */