linux/arch/sparc/mm/init.c
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   1/*
   2 *  linux/arch/sparc/mm/init.c
   3 *
   4 *  Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
   5 *  Copyright (C) 1995 Eddie C. Dost (ecd@skynet.be)
   6 *  Copyright (C) 1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
   7 *  Copyright (C) 2000 Anton Blanchard (anton@samba.org)
   8 */
   9
  10#include <linux/module.h>
  11#include <linux/signal.h>
  12#include <linux/sched.h>
  13#include <linux/kernel.h>
  14#include <linux/errno.h>
  15#include <linux/string.h>
  16#include <linux/types.h>
  17#include <linux/ptrace.h>
  18#include <linux/mman.h>
  19#include <linux/mm.h>
  20#include <linux/swap.h>
  21#include <linux/initrd.h>
  22#include <linux/init.h>
  23#include <linux/highmem.h>
  24#include <linux/bootmem.h>
  25#include <linux/pagemap.h>
  26
  27#include <asm/system.h>
  28#include <asm/vac-ops.h>
  29#include <asm/page.h>
  30#include <asm/pgtable.h>
  31#include <asm/vaddrs.h>
  32#include <asm/pgalloc.h>        /* bug in asm-generic/tlb.h: check_pgt_cache */
  33#include <asm/tlb.h>
  34#include <asm/prom.h>
  35
  36DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
  37
  38unsigned long *sparc_valid_addr_bitmap;
  39
  40unsigned long phys_base;
  41unsigned long pfn_base;
  42
  43unsigned long page_kernel;
  44
  45struct sparc_phys_banks sp_banks[SPARC_PHYS_BANKS+1];
  46unsigned long sparc_unmapped_base;
  47
  48struct pgtable_cache_struct pgt_quicklists;
  49
  50/* References to section boundaries */
  51extern char __init_begin, __init_end, _start, _end, etext , edata;
  52
  53/* Initial ramdisk setup */
  54extern unsigned int sparc_ramdisk_image;
  55extern unsigned int sparc_ramdisk_size;
  56
  57unsigned long highstart_pfn, highend_pfn;
  58
  59pte_t *kmap_pte;
  60pgprot_t kmap_prot;
  61
  62#define kmap_get_fixmap_pte(vaddr) \
  63        pte_offset_kernel(pmd_offset(pgd_offset_k(vaddr), (vaddr)), (vaddr))
  64
  65void __init kmap_init(void)
  66{
  67        /* cache the first kmap pte */
  68        kmap_pte = kmap_get_fixmap_pte(__fix_to_virt(FIX_KMAP_BEGIN));
  69        kmap_prot = __pgprot(SRMMU_ET_PTE | SRMMU_PRIV | SRMMU_CACHE);
  70}
  71
  72void show_mem(void)
  73{
  74        printk("Mem-info:\n");
  75        show_free_areas();
  76        printk("Free swap:       %6ldkB\n",
  77               nr_swap_pages << (PAGE_SHIFT-10));
  78        printk("%ld pages of RAM\n", totalram_pages);
  79        printk("%ld free pages\n", nr_free_pages());
  80#if 0 /* undefined pgtable_cache_size, pgd_cache_size */
  81        printk("%ld pages in page table cache\n",pgtable_cache_size);
  82#ifndef CONFIG_SMP
  83        if (sparc_cpu_model == sun4m || sparc_cpu_model == sun4d)
  84                printk("%ld entries in page dir cache\n",pgd_cache_size);
  85#endif  
  86#endif
  87}
  88
  89void __init sparc_context_init(int numctx)
  90{
  91        int ctx;
  92
  93        ctx_list_pool = __alloc_bootmem(numctx * sizeof(struct ctx_list), SMP_CACHE_BYTES, 0UL);
  94
  95        for(ctx = 0; ctx < numctx; ctx++) {
  96                struct ctx_list *clist;
  97
  98                clist = (ctx_list_pool + ctx);
  99                clist->ctx_number = ctx;
 100                clist->ctx_mm = NULL;
 101        }
 102        ctx_free.next = ctx_free.prev = &ctx_free;
 103        ctx_used.next = ctx_used.prev = &ctx_used;
 104        for(ctx = 0; ctx < numctx; ctx++)
 105                add_to_free_ctxlist(ctx_list_pool + ctx);
 106}
 107
 108extern unsigned long cmdline_memory_size;
 109unsigned long last_valid_pfn;
 110
 111unsigned long calc_highpages(void)
 112{
 113        int i;
 114        int nr = 0;
 115
 116        for (i = 0; sp_banks[i].num_bytes != 0; i++) {
 117                unsigned long start_pfn = sp_banks[i].base_addr >> PAGE_SHIFT;
 118                unsigned long end_pfn = (sp_banks[i].base_addr + sp_banks[i].num_bytes) >> PAGE_SHIFT;
 119
 120                if (end_pfn <= max_low_pfn)
 121                        continue;
 122
 123                if (start_pfn < max_low_pfn)
 124                        start_pfn = max_low_pfn;
 125
 126                nr += end_pfn - start_pfn;
 127        }
 128
 129        return nr;
 130}
 131
 132static unsigned long calc_max_low_pfn(void)
 133{
 134        int i;
 135        unsigned long tmp = pfn_base + (SRMMU_MAXMEM >> PAGE_SHIFT);
 136        unsigned long curr_pfn, last_pfn;
 137
 138        last_pfn = (sp_banks[0].base_addr + sp_banks[0].num_bytes) >> PAGE_SHIFT;
 139        for (i = 1; sp_banks[i].num_bytes != 0; i++) {
 140                curr_pfn = sp_banks[i].base_addr >> PAGE_SHIFT;
 141
 142                if (curr_pfn >= tmp) {
 143                        if (last_pfn < tmp)
 144                                tmp = last_pfn;
 145                        break;
 146                }
 147
 148                last_pfn = (sp_banks[i].base_addr + sp_banks[i].num_bytes) >> PAGE_SHIFT;
 149        }
 150
 151        return tmp;
 152}
 153
 154unsigned long __init bootmem_init(unsigned long *pages_avail)
 155{
 156        unsigned long bootmap_size, start_pfn;
 157        unsigned long end_of_phys_memory = 0UL;
 158        unsigned long bootmap_pfn, bytes_avail, size;
 159        int i;
 160
 161        bytes_avail = 0UL;
 162        for (i = 0; sp_banks[i].num_bytes != 0; i++) {
 163                end_of_phys_memory = sp_banks[i].base_addr +
 164                        sp_banks[i].num_bytes;
 165                bytes_avail += sp_banks[i].num_bytes;
 166                if (cmdline_memory_size) {
 167                        if (bytes_avail > cmdline_memory_size) {
 168                                unsigned long slack = bytes_avail - cmdline_memory_size;
 169
 170                                bytes_avail -= slack;
 171                                end_of_phys_memory -= slack;
 172
 173                                sp_banks[i].num_bytes -= slack;
 174                                if (sp_banks[i].num_bytes == 0) {
 175                                        sp_banks[i].base_addr = 0xdeadbeef;
 176                                } else {
 177                                        sp_banks[i+1].num_bytes = 0;
 178                                        sp_banks[i+1].base_addr = 0xdeadbeef;
 179                                }
 180                                break;
 181                        }
 182                }
 183        }
 184
 185        /* Start with page aligned address of last symbol in kernel
 186         * image.  
 187         */
 188        start_pfn  = (unsigned long)__pa(PAGE_ALIGN((unsigned long) &_end));
 189
 190        /* Now shift down to get the real physical page frame number. */
 191        start_pfn >>= PAGE_SHIFT;
 192
 193        bootmap_pfn = start_pfn;
 194
 195        max_pfn = end_of_phys_memory >> PAGE_SHIFT;
 196
 197        max_low_pfn = max_pfn;
 198        highstart_pfn = highend_pfn = max_pfn;
 199
 200        if (max_low_pfn > pfn_base + (SRMMU_MAXMEM >> PAGE_SHIFT)) {
 201                highstart_pfn = pfn_base + (SRMMU_MAXMEM >> PAGE_SHIFT);
 202                max_low_pfn = calc_max_low_pfn();
 203                printk(KERN_NOTICE "%ldMB HIGHMEM available.\n",
 204                    calc_highpages() >> (20 - PAGE_SHIFT));
 205        }
 206
 207#ifdef CONFIG_BLK_DEV_INITRD
 208        /* Now have to check initial ramdisk, so that bootmap does not overwrite it */
 209        if (sparc_ramdisk_image) {
 210                if (sparc_ramdisk_image >= (unsigned long)&_end - 2 * PAGE_SIZE)
 211                        sparc_ramdisk_image -= KERNBASE;
 212                initrd_start = sparc_ramdisk_image + phys_base;
 213                initrd_end = initrd_start + sparc_ramdisk_size;
 214                if (initrd_end > end_of_phys_memory) {
 215                        printk(KERN_CRIT "initrd extends beyond end of memory "
 216                                         "(0x%016lx > 0x%016lx)\ndisabling initrd\n",
 217                               initrd_end, end_of_phys_memory);
 218                        initrd_start = 0;
 219                }
 220                if (initrd_start) {
 221                        if (initrd_start >= (start_pfn << PAGE_SHIFT) &&
 222                            initrd_start < (start_pfn << PAGE_SHIFT) + 2 * PAGE_SIZE)
 223                                bootmap_pfn = PAGE_ALIGN (initrd_end) >> PAGE_SHIFT;
 224                }
 225        }
 226#endif  
 227        /* Initialize the boot-time allocator. */
 228        bootmap_size = init_bootmem_node(NODE_DATA(0), bootmap_pfn, pfn_base,
 229                                         max_low_pfn);
 230
 231        /* Now register the available physical memory with the
 232         * allocator.
 233         */
 234        *pages_avail = 0;
 235        for (i = 0; sp_banks[i].num_bytes != 0; i++) {
 236                unsigned long curr_pfn, last_pfn;
 237
 238                curr_pfn = sp_banks[i].base_addr >> PAGE_SHIFT;
 239                if (curr_pfn >= max_low_pfn)
 240                        break;
 241
 242                last_pfn = (sp_banks[i].base_addr + sp_banks[i].num_bytes) >> PAGE_SHIFT;
 243                if (last_pfn > max_low_pfn)
 244                        last_pfn = max_low_pfn;
 245
 246                /*
 247                 * .. finally, did all the rounding and playing
 248                 * around just make the area go away?
 249                 */
 250                if (last_pfn <= curr_pfn)
 251                        continue;
 252
 253                size = (last_pfn - curr_pfn) << PAGE_SHIFT;
 254                *pages_avail += last_pfn - curr_pfn;
 255
 256                free_bootmem(sp_banks[i].base_addr, size);
 257        }
 258
 259#ifdef CONFIG_BLK_DEV_INITRD
 260        if (initrd_start) {
 261                /* Reserve the initrd image area. */
 262                size = initrd_end - initrd_start;
 263                reserve_bootmem(initrd_start, size, BOOTMEM_DEFAULT);
 264                *pages_avail -= PAGE_ALIGN(size) >> PAGE_SHIFT;
 265
 266                initrd_start = (initrd_start - phys_base) + PAGE_OFFSET;
 267                initrd_end = (initrd_end - phys_base) + PAGE_OFFSET;            
 268        }
 269#endif
 270        /* Reserve the kernel text/data/bss. */
 271        size = (start_pfn << PAGE_SHIFT) - phys_base;
 272        reserve_bootmem(phys_base, size, BOOTMEM_DEFAULT);
 273        *pages_avail -= PAGE_ALIGN(size) >> PAGE_SHIFT;
 274
 275        /* Reserve the bootmem map.   We do not account for it
 276         * in pages_avail because we will release that memory
 277         * in free_all_bootmem.
 278         */
 279        size = bootmap_size;
 280        reserve_bootmem((bootmap_pfn << PAGE_SHIFT), size, BOOTMEM_DEFAULT);
 281        *pages_avail -= PAGE_ALIGN(size) >> PAGE_SHIFT;
 282
 283        return max_pfn;
 284}
 285
 286/*
 287 * check_pgt_cache
 288 *
 289 * This is called at the end of unmapping of VMA (zap_page_range),
 290 * to rescan the page cache for architecture specific things,
 291 * presumably something like sun4/sun4c PMEGs. Most architectures
 292 * define check_pgt_cache empty.
 293 *
 294 * We simply copy the 2.4 implementation for now.
 295 */
 296static int pgt_cache_water[2] = { 25, 50 };
 297
 298void check_pgt_cache(void)
 299{
 300        do_check_pgt_cache(pgt_cache_water[0], pgt_cache_water[1]);
 301}
 302
 303/*
 304 * paging_init() sets up the page tables: We call the MMU specific
 305 * init routine based upon the Sun model type on the Sparc.
 306 *
 307 */
 308extern void sun4c_paging_init(void);
 309extern void srmmu_paging_init(void);
 310extern void device_scan(void);
 311
 312pgprot_t PAGE_SHARED __read_mostly;
 313EXPORT_SYMBOL(PAGE_SHARED);
 314
 315void __init paging_init(void)
 316{
 317        switch(sparc_cpu_model) {
 318        case sun4c:
 319        case sun4e:
 320        case sun4:
 321                sun4c_paging_init();
 322                sparc_unmapped_base = 0xe0000000;
 323                BTFIXUPSET_SETHI(sparc_unmapped_base, 0xe0000000);
 324                break;
 325        case sun4m:
 326        case sun4d:
 327                srmmu_paging_init();
 328                sparc_unmapped_base = 0x50000000;
 329                BTFIXUPSET_SETHI(sparc_unmapped_base, 0x50000000);
 330                break;
 331        default:
 332                prom_printf("paging_init: Cannot init paging on this Sparc\n");
 333                prom_printf("paging_init: sparc_cpu_model = %d\n", sparc_cpu_model);
 334                prom_printf("paging_init: Halting...\n");
 335                prom_halt();
 336        };
 337
 338        /* Initialize the protection map with non-constant, MMU dependent values. */
 339        protection_map[0] = PAGE_NONE;
 340        protection_map[1] = PAGE_READONLY;
 341        protection_map[2] = PAGE_COPY;
 342        protection_map[3] = PAGE_COPY;
 343        protection_map[4] = PAGE_READONLY;
 344        protection_map[5] = PAGE_READONLY;
 345        protection_map[6] = PAGE_COPY;
 346        protection_map[7] = PAGE_COPY;
 347        protection_map[8] = PAGE_NONE;
 348        protection_map[9] = PAGE_READONLY;
 349        protection_map[10] = PAGE_SHARED;
 350        protection_map[11] = PAGE_SHARED;
 351        protection_map[12] = PAGE_READONLY;
 352        protection_map[13] = PAGE_READONLY;
 353        protection_map[14] = PAGE_SHARED;
 354        protection_map[15] = PAGE_SHARED;
 355        btfixup();
 356        prom_build_devicetree();
 357        device_scan();
 358}
 359
 360static void __init taint_real_pages(void)
 361{
 362        int i;
 363
 364        for (i = 0; sp_banks[i].num_bytes; i++) {
 365                unsigned long start, end;
 366
 367                start = sp_banks[i].base_addr;
 368                end = start + sp_banks[i].num_bytes;
 369
 370                while (start < end) {
 371                        set_bit(start >> 20, sparc_valid_addr_bitmap);
 372                        start += PAGE_SIZE;
 373                }
 374        }
 375}
 376
 377static void map_high_region(unsigned long start_pfn, unsigned long end_pfn)
 378{
 379        unsigned long tmp;
 380
 381#ifdef CONFIG_DEBUG_HIGHMEM
 382        printk("mapping high region %08lx - %08lx\n", start_pfn, end_pfn);
 383#endif
 384
 385        for (tmp = start_pfn; tmp < end_pfn; tmp++) {
 386                struct page *page = pfn_to_page(tmp);
 387
 388                ClearPageReserved(page);
 389                init_page_count(page);
 390                __free_page(page);
 391                totalhigh_pages++;
 392        }
 393}
 394
 395void __init mem_init(void)
 396{
 397        int codepages = 0;
 398        int datapages = 0;
 399        int initpages = 0; 
 400        int reservedpages = 0;
 401        int i;
 402
 403        if (PKMAP_BASE+LAST_PKMAP*PAGE_SIZE >= FIXADDR_START) {
 404                prom_printf("BUG: fixmap and pkmap areas overlap\n");
 405                prom_printf("pkbase: 0x%lx pkend: 0x%lx fixstart 0x%lx\n",
 406                       PKMAP_BASE,
 407                       (unsigned long)PKMAP_BASE+LAST_PKMAP*PAGE_SIZE,
 408                       FIXADDR_START);
 409                prom_printf("Please mail sparclinux@vger.kernel.org.\n");
 410                prom_halt();
 411        }
 412
 413
 414        /* Saves us work later. */
 415        memset((void *)&empty_zero_page, 0, PAGE_SIZE);
 416
 417        i = last_valid_pfn >> ((20 - PAGE_SHIFT) + 5);
 418        i += 1;
 419        sparc_valid_addr_bitmap = (unsigned long *)
 420                __alloc_bootmem(i << 2, SMP_CACHE_BYTES, 0UL);
 421
 422        if (sparc_valid_addr_bitmap == NULL) {
 423                prom_printf("mem_init: Cannot alloc valid_addr_bitmap.\n");
 424                prom_halt();
 425        }
 426        memset(sparc_valid_addr_bitmap, 0, i << 2);
 427
 428        taint_real_pages();
 429
 430        max_mapnr = last_valid_pfn - pfn_base;
 431        high_memory = __va(max_low_pfn << PAGE_SHIFT);
 432
 433        totalram_pages = free_all_bootmem();
 434
 435        for (i = 0; sp_banks[i].num_bytes != 0; i++) {
 436                unsigned long start_pfn = sp_banks[i].base_addr >> PAGE_SHIFT;
 437                unsigned long end_pfn = (sp_banks[i].base_addr + sp_banks[i].num_bytes) >> PAGE_SHIFT;
 438
 439                num_physpages += sp_banks[i].num_bytes >> PAGE_SHIFT;
 440
 441                if (end_pfn <= highstart_pfn)
 442                        continue;
 443
 444                if (start_pfn < highstart_pfn)
 445                        start_pfn = highstart_pfn;
 446
 447                map_high_region(start_pfn, end_pfn);
 448        }
 449        
 450        totalram_pages += totalhigh_pages;
 451
 452        codepages = (((unsigned long) &etext) - ((unsigned long)&_start));
 453        codepages = PAGE_ALIGN(codepages) >> PAGE_SHIFT;
 454        datapages = (((unsigned long) &edata) - ((unsigned long)&etext));
 455        datapages = PAGE_ALIGN(datapages) >> PAGE_SHIFT;
 456        initpages = (((unsigned long) &__init_end) - ((unsigned long) &__init_begin));
 457        initpages = PAGE_ALIGN(initpages) >> PAGE_SHIFT;
 458
 459        /* Ignore memory holes for the purpose of counting reserved pages */
 460        for (i=0; i < max_low_pfn; i++)
 461                if (test_bit(i >> (20 - PAGE_SHIFT), sparc_valid_addr_bitmap)
 462                    && PageReserved(pfn_to_page(i)))
 463                        reservedpages++;
 464
 465        printk(KERN_INFO "Memory: %luk/%luk available (%dk kernel code, %dk reserved, %dk data, %dk init, %ldk highmem)\n",
 466               (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
 467               num_physpages << (PAGE_SHIFT - 10),
 468               codepages << (PAGE_SHIFT-10),
 469               reservedpages << (PAGE_SHIFT - 10),
 470               datapages << (PAGE_SHIFT-10), 
 471               initpages << (PAGE_SHIFT-10),
 472               totalhigh_pages << (PAGE_SHIFT-10));
 473}
 474
 475void free_initmem (void)
 476{
 477        unsigned long addr;
 478
 479        addr = (unsigned long)(&__init_begin);
 480        for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
 481                struct page *p;
 482
 483                p = virt_to_page(addr);
 484
 485                ClearPageReserved(p);
 486                init_page_count(p);
 487                __free_page(p);
 488                totalram_pages++;
 489                num_physpages++;
 490        }
 491        printk (KERN_INFO "Freeing unused kernel memory: %dk freed\n", (&__init_end - &__init_begin) >> 10);
 492}
 493
 494#ifdef CONFIG_BLK_DEV_INITRD
 495void free_initrd_mem(unsigned long start, unsigned long end)
 496{
 497        if (start < end)
 498                printk (KERN_INFO "Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
 499        for (; start < end; start += PAGE_SIZE) {
 500                struct page *p = virt_to_page(start);
 501
 502                ClearPageReserved(p);
 503                init_page_count(p);
 504                __free_page(p);
 505                num_physpages++;
 506        }
 507}
 508#endif
 509
 510void sparc_flush_page_to_ram(struct page *page)
 511{
 512        unsigned long vaddr = (unsigned long)page_address(page);
 513
 514        if (vaddr)
 515                __flush_page_to_ram(vaddr);
 516}
 517