arch/metag/mm/init.c

   1 /*
   2  *  Copyright (C) 2005,2006,2007,2008,2009,2010 Imagination Technologies
   3  *
   4  */
   5
   6 #include <linux/export.h>
   7 #include <linux/mm.h>
   8 #include <linux/swap.h>
   9 #include <linux/init.h>
  10 #include <linux/bootmem.h>
  11 #include <linux/pagemap.h>
  12 #include <linux/percpu.h>
  13 #include <linux/memblock.h>
  14 #include <linux/initrd.h>
  15
  16 #include <asm/setup.h>
  17 #include <asm/page.h>
  18 #include <asm/pgalloc.h>
  19 #include <asm/mmu.h>
  20 #include <asm/mmu_context.h>
  21 #include <asm/sections.h>
  22 #include <asm/tlb.h>
  23 #include <asm/user_gateway.h>
  24 #include <asm/mmzone.h>
  25 #include <asm/fixmap.h>
  26
  27 unsigned long pfn_base;
  28 EXPORT_SYMBOL(pfn_base);
  29
  30 pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_data;
  31
  32 unsigned long empty_zero_page;
  33 EXPORT_SYMBOL(empty_zero_page);
  34
  35 extern char __user_gateway_start;
  36 extern char __user_gateway_end;
  37
  38 void *gateway_page;
  39
  40 /*
  41  * Insert the gateway page into a set of page tables, creating the
  42  * page tables if necessary.
  43  */
  44 static void insert_gateway_page(pgd_t *pgd, unsigned long address)
  45 {
  46         pud_t *pud;
  47         pmd_t *pmd;
  48         pte_t *pte;
  49
  50         BUG_ON(!pgd_present(*pgd));
  51
  52         pud = pud_offset(pgd, address);
  53         BUG_ON(!pud_present(*pud));
  54
  55         pmd = pmd_offset(pud, address);
  56         if (!pmd_present(*pmd)) {
  57                 pte = alloc_bootmem_pages(PAGE_SIZE);
  58                 set_pmd(pmd, __pmd(_PAGE_TABLE | __pa(pte)));
  59         }
  60
  61         pte = pte_offset_kernel(pmd, address);
  62         set_pte(pte, pfn_pte(__pa(gateway_page) >> PAGE_SHIFT, PAGE_READONLY));
  63 }
  64
  65 /* Alloc and map a page in a known location accessible to userspace. */
  66 static void __init user_gateway_init(void)
  67 {
  68         unsigned long address = USER_GATEWAY_PAGE;
  69         int offset = pgd_index(address);
  70         pgd_t *pgd;
  71
  72         gateway_page = alloc_bootmem_pages(PAGE_SIZE);
  73
  74         pgd = swapper_pg_dir + offset;
  75         insert_gateway_page(pgd, address);
  76
  77 #ifdef CONFIG_METAG_META12
  78         /*
  79          * Insert the gateway page into our current page tables even
  80          * though we've already inserted it into our reference page
  81          * table (swapper_pg_dir). This is because with a META1 mmu we
  82          * copy just the user address range and not the gateway page
  83          * entry on context switch, see switch_mmu().
  84          */
  85         pgd = (pgd_t *)mmu_get_base() + offset;
  86         insert_gateway_page(pgd, address);
  87 #endif /* CONFIG_METAG_META12 */
  88
  89         BUG_ON((&__user_gateway_end - &__user_gateway_start) > PAGE_SIZE);
  90
  91         gateway_page += (address & ~PAGE_MASK);
  92
  93         memcpy(gateway_page, &__user_gateway_start,
  94                &__user_gateway_end - &__user_gateway_start);
  95
  96         /*
  97          * We don't need to flush the TLB here, there should be no mapping
  98          * present at boot for this address and only valid mappings are in
  99          * the TLB (apart from on Meta 1.x, but those cached invalid
 100          * mappings should be impossible to hit here).
 101          *
 102          * We don't flush the code cache here even though we have written
 103          * code through the data cache and they may not be coherent. At
 104          * this point we assume there is no stale data in the code cache
 105          * for this address so there is no need to flush.
 106          */
 107 }
 108
 109 static void __init allocate_pgdat(unsigned int nid)
 110 {
 111         unsigned long start_pfn, end_pfn;
 112 #ifdef CONFIG_NEED_MULTIPLE_NODES
 113         unsigned long phys;
 114 #endif
 115
 116         get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
 117
 118 #ifdef CONFIG_NEED_MULTIPLE_NODES
 119         phys = __memblock_alloc_base(sizeof(struct pglist_data),
 120                                 SMP_CACHE_BYTES, end_pfn << PAGE_SHIFT);
 121         /* Retry with all of system memory */
 122         if (!phys)
 123                 phys = __memblock_alloc_base(sizeof(struct pglist_data),
 124                                              SMP_CACHE_BYTES,
 125                                              memblock_end_of_DRAM());
 126         if (!phys)
 127                 panic("Can't allocate pgdat for node %d\n", nid);
 128
 129         NODE_DATA(nid) = __va(phys);
 130         memset(NODE_DATA(nid), 0, sizeof(struct pglist_data));
 131
 132         NODE_DATA(nid)->bdata = &bootmem_node_data[nid];
 133 #endif
 134
 135         NODE_DATA(nid)->node_start_pfn = start_pfn;
 136         NODE_DATA(nid)->node_spanned_pages = end_pfn - start_pfn;
 137 }
 138
 139 static void __init bootmem_init_one_node(unsigned int nid)
 140 {
 141         unsigned long total_pages, paddr;
 142         unsigned long end_pfn;
 143         struct pglist_data *p;
 144
 145         p = NODE_DATA(nid);
 146
 147         /* Nothing to do.. */
 148         if (!p->node_spanned_pages)
 149                 return;
 150
 151         end_pfn = pgdat_end_pfn(p);
 152 #ifdef CONFIG_HIGHMEM
 153         if (end_pfn > max_low_pfn)
 154                 end_pfn = max_low_pfn;
 155 #endif
 156
 157         total_pages = bootmem_bootmap_pages(end_pfn - p->node_start_pfn);
 158
 159         paddr = memblock_alloc(total_pages << PAGE_SHIFT, PAGE_SIZE);
 160         if (!paddr)
 161                 panic("Can't allocate bootmap for nid[%d]\n", nid);
 162
 163         init_bootmem_node(p, paddr >> PAGE_SHIFT, p->node_start_pfn, end_pfn);
 164
 165         free_bootmem_with_active_regions(nid, end_pfn);
 166
 167         /*
 168          * XXX Handle initial reservations for the system memory node
 169          * only for the moment, we'll refactor this later for handling
 170          * reservations in other nodes.
 171          */
 172         if (nid == 0) {
 173                 struct memblock_region *reg;
 174
 175                 /* Reserve the sections we're already using. */
 176                 for_each_memblock(reserved, reg) {
 177                         unsigned long size = reg->size;
 178
 179 #ifdef CONFIG_HIGHMEM
 180                         /* ...but not highmem */
 181                         if (PFN_DOWN(reg->base) >= highstart_pfn)
 182                                 continue;
 183
 184                         if (PFN_UP(reg->base + size) > highstart_pfn)
 185                                 size = (highstart_pfn - PFN_DOWN(reg->base))
 186                                        << PAGE_SHIFT;
 187 #endif
 188
 189                         reserve_bootmem(reg->base, size, BOOTMEM_DEFAULT);
 190                 }
 191         }
 192
 193         sparse_memory_present_with_active_regions(nid);
 194 }
 195
 196 static void __init do_init_bootmem(void)
 197 {
 198         struct memblock_region *reg;
 199         int i;
 200
 201         /* Add active regions with valid PFNs. */
 202         for_each_memblock(memory, reg) {
 203                 unsigned long start_pfn, end_pfn;
 204                 start_pfn = memblock_region_memory_base_pfn(reg);
 205                 end_pfn = memblock_region_memory_end_pfn(reg);
 206                 memblock_set_node(PFN_PHYS(start_pfn),
 207                                   PFN_PHYS(end_pfn - start_pfn),
 208                                   &memblock.memory, 0);
 209         }
 210
 211         /* All of system RAM sits in node 0 for the non-NUMA case */
 212         allocate_pgdat(0);
 213         node_set_online(0);
 214
 215         soc_mem_setup();
 216
 217         for_each_online_node(i)
 218                 bootmem_init_one_node(i);
 219
 220         sparse_init();
 221 }
 222
 223 extern char _heap_start[];
 224
 225 static void __init init_and_reserve_mem(void)
 226 {
 227         unsigned long start_pfn, heap_start;
 228         u64 base = min_low_pfn << PAGE_SHIFT;
 229         u64 size = (max_low_pfn << PAGE_SHIFT) - base;
 230
 231         heap_start = (unsigned long) &_heap_start;
 232
 233         memblock_add(base, size);
 234
 235         /*
 236          * Partially used pages are not usable - thus
 237          * we are rounding upwards:
 238          */
 239         start_pfn = PFN_UP(__pa(heap_start));
 240
 241         /*
 242          * Reserve the kernel text.
 243          */
 244         memblock_reserve(base, (PFN_PHYS(start_pfn) + PAGE_SIZE - 1) - base);
 245
 246 #ifdef CONFIG_HIGHMEM
 247         /*
 248          * Add & reserve highmem, so page structures are initialised.
 249          */
 250         base = highstart_pfn << PAGE_SHIFT;
 251         size = (highend_pfn << PAGE_SHIFT) - base;
 252         if (size) {
 253                 memblock_add(base, size);
 254                 memblock_reserve(base, size);
 255         }
 256 #endif
 257 }
 258
 259 #ifdef CONFIG_HIGHMEM
 260 /*
 261  * Ensure we have allocated page tables in swapper_pg_dir for the
 262  * fixed mappings range from 'start' to 'end'.
 263  */
 264 static void __init allocate_pgtables(unsigned long start, unsigned long end)
 265 {
 266         pgd_t *pgd;
 267         pmd_t *pmd;
 268         pte_t *pte;
 269         int i, j;
 270         unsigned long vaddr;
 271
 272         vaddr = start;
 273         i = pgd_index(vaddr);
 274         j = pmd_index(vaddr);
 275         pgd = swapper_pg_dir + i;
 276
 277         for ( ; (i < PTRS_PER_PGD) && (vaddr != end); pgd++, i++) {
 278                 pmd = (pmd_t *)pgd;
 279                 for (; (j < PTRS_PER_PMD) && (vaddr != end); pmd++, j++) {
 280                         vaddr += PMD_SIZE;
 281
 282                         if (!pmd_none(*pmd))
 283                                 continue;
 284
 285                         pte = (pte_t *)alloc_bootmem_low_pages(PAGE_SIZE);
 286                         pmd_populate_kernel(&init_mm, pmd, pte);
 287                 }
 288                 j = 0;
 289         }
 290 }
 291
 292 static void __init fixedrange_init(void)
 293 {
 294         unsigned long vaddr, end;
 295         pgd_t *pgd;
 296         pud_t *pud;
 297         pmd_t *pmd;
 298         pte_t *pte;
 299
 300         /*
 301          * Fixed mappings:
 302          */
 303         vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
 304         end = (FIXADDR_TOP + PMD_SIZE - 1) & PMD_MASK;
 305         allocate_pgtables(vaddr, end);
 306
 307         /*
 308          * Permanent kmaps:
 309          */
 310         vaddr = PKMAP_BASE;
 311         allocate_pgtables(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP);
 312
 313         pgd = swapper_pg_dir + pgd_index(vaddr);
 314         pud = pud_offset(pgd, vaddr);
 315         pmd = pmd_offset(pud, vaddr);
 316         pte = pte_offset_kernel(pmd, vaddr);
 317         pkmap_page_table = pte;
 318 }
 319 #endif /* CONFIG_HIGHMEM */
 320
 321 /*
 322  * paging_init() continues the virtual memory environment setup which
 323  * was begun by the code in arch/metag/kernel/setup.c.
 324  */
 325 void __init paging_init(unsigned long mem_end)
 326 {
 327         unsigned long max_zone_pfns[MAX_NR_ZONES];
 328         int nid;
 329
 330         init_and_reserve_mem();
 331
 332         memblock_allow_resize();
 333
 334         memblock_dump_all();
 335
 336         nodes_clear(node_online_map);
 337
 338         init_new_context(&init_task, &init_mm);
 339
 340         memset(swapper_pg_dir, 0, sizeof(swapper_pg_dir));
 341
 342         do_init_bootmem();
 343         mmu_init(mem_end);
 344
 345 #ifdef CONFIG_HIGHMEM
 346         fixedrange_init();
 347         kmap_init();
 348 #endif
 349
 350         /* Initialize the zero page to a bootmem page, already zeroed. */
 351         empty_zero_page = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
 352
 353         user_gateway_init();
 354
 355         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
 356
 357         for_each_online_node(nid) {
 358                 pg_data_t *pgdat = NODE_DATA(nid);
 359                 unsigned long low, start_pfn;
 360
 361                 start_pfn = pgdat->bdata->node_min_pfn;
 362                 low = pgdat->bdata->node_low_pfn;
 363
 364                 if (max_zone_pfns[ZONE_NORMAL] < low)
 365                         max_zone_pfns[ZONE_NORMAL] = low;
 366
 367 #ifdef CONFIG_HIGHMEM
 368                 max_zone_pfns[ZONE_HIGHMEM] = highend_pfn;
 369 #endif
 370                 pr_info("Node %u: start_pfn = 0x%lx, low = 0x%lx\n",
 371                         nid, start_pfn, low);
 372         }
 373
 374         free_area_init_nodes(max_zone_pfns);
 375 }
 376
 377 void __init mem_init(void)
 378 {
 379 #ifdef CONFIG_HIGHMEM
 380         unsigned long tmp;
 381
 382         /*
 383          * Explicitly reset zone->managed_pages because highmem pages are
 384          * freed before calling free_all_bootmem();
 385          */
 386         reset_all_zones_managed_pages();
 387         for (tmp = highstart_pfn; tmp < highend_pfn; tmp++)
 388                 free_highmem_page(pfn_to_page(tmp));
 389 #endif /* CONFIG_HIGHMEM */
 390
 391         free_all_bootmem();
 392         mem_init_print_info(NULL);
 393 }
 394
 395 void free_initmem(void)
 396 {
 397         free_initmem_default(POISON_FREE_INITMEM);
 398 }
 399
 400 #ifdef CONFIG_BLK_DEV_INITRD
 401 void free_initrd_mem(unsigned long start, unsigned long end)
 402 {
 403         free_reserved_area((void *)start, (void *)end, POISON_FREE_INITMEM,
 404                            "initrd");
 405 }
 406 #endif