linux/arch/sparc/mm/init.c
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   1/*  $Id: init.c,v 1.103 2001/11/19 19:03:08 davem Exp $
   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
  26#include <asm/system.h>
  27#include <asm/vac-ops.h>
  28#include <asm/page.h>
  29#include <asm/pgtable.h>
  30#include <asm/vaddrs.h>
  31#include <asm/pgalloc.h>        /* bug in asm-generic/tlb.h: check_pgt_cache */
  32#include <asm/tlb.h>
  33#include <asm/prom.h>
  34
  35DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
  36
  37unsigned long *sparc_valid_addr_bitmap;
  38
  39unsigned long phys_base;
  40unsigned long pfn_base;
  41
  42unsigned long page_kernel;
  43
  44struct sparc_phys_banks sp_banks[SPARC_PHYS_BANKS+1];
  45unsigned long sparc_unmapped_base;
  46
  47struct pgtable_cache_struct pgt_quicklists;
  48
  49/* References to section boundaries */
  50extern char __init_begin, __init_end, _start, _end, etext , edata;
  51
  52/* Initial ramdisk setup */
  53extern unsigned int sparc_ramdisk_image;
  54extern unsigned int sparc_ramdisk_size;
  55
  56unsigned long highstart_pfn, highend_pfn;
  57
  58pte_t *kmap_pte;
  59pgprot_t kmap_prot;
  60
  61#define kmap_get_fixmap_pte(vaddr) \
  62        pte_offset_kernel(pmd_offset(pgd_offset_k(vaddr), (vaddr)), (vaddr))
  63
  64void __init kmap_init(void)
  65{
  66        /* cache the first kmap pte */
  67        kmap_pte = kmap_get_fixmap_pte(__fix_to_virt(FIX_KMAP_BEGIN));
  68        kmap_prot = __pgprot(SRMMU_ET_PTE | SRMMU_PRIV | SRMMU_CACHE);
  69}
  70
  71void show_mem(void)
  72{
  73        printk("Mem-info:\n");
  74        show_free_areas();
  75        printk("Free swap:       %6ldkB\n",
  76               nr_swap_pages << (PAGE_SHIFT-10));
  77        printk("%ld pages of RAM\n", totalram_pages);
  78        printk("%ld free pages\n", nr_free_pages());
  79#if 0 /* undefined pgtable_cache_size, pgd_cache_size */
  80        printk("%ld pages in page table cache\n",pgtable_cache_size);
  81#ifndef CONFIG_SMP
  82        if (sparc_cpu_model == sun4m || sparc_cpu_model == sun4d)
  83                printk("%ld entries in page dir cache\n",pgd_cache_size);
  84#endif  
  85#endif
  86}
  87
  88void __init sparc_context_init(int numctx)
  89{
  90        int ctx;
  91
  92        ctx_list_pool = __alloc_bootmem(numctx * sizeof(struct ctx_list), SMP_CACHE_BYTES, 0UL);
  93
  94        for(ctx = 0; ctx < numctx; ctx++) {
  95                struct ctx_list *clist;
  96
  97                clist = (ctx_list_pool + ctx);
  98                clist->ctx_number = ctx;
  99                clist->ctx_mm = NULL;
 100        }
 101        ctx_free.next = ctx_free.prev = &ctx_free;
 102        ctx_used.next = ctx_used.prev = &ctx_used;
 103        for(ctx = 0; ctx < numctx; ctx++)
 104                add_to_free_ctxlist(ctx_list_pool + ctx);
 105}
 106
 107extern unsigned long cmdline_memory_size;
 108unsigned long last_valid_pfn;
 109
 110unsigned long calc_highpages(void)
 111{
 112        int i;
 113        int nr = 0;
 114
 115        for (i = 0; sp_banks[i].num_bytes != 0; i++) {
 116                unsigned long start_pfn = sp_banks[i].base_addr >> PAGE_SHIFT;
 117                unsigned long end_pfn = (sp_banks[i].base_addr + sp_banks[i].num_bytes) >> PAGE_SHIFT;
 118
 119                if (end_pfn <= max_low_pfn)
 120                        continue;
 121
 122                if (start_pfn < max_low_pfn)
 123                        start_pfn = max_low_pfn;
 124
 125                nr += end_pfn - start_pfn;
 126        }
 127
 128        return nr;
 129}
 130
 131unsigned long calc_max_low_pfn(void)
 132{
 133        int i;
 134        unsigned long tmp = pfn_base + (SRMMU_MAXMEM >> PAGE_SHIFT);
 135        unsigned long curr_pfn, last_pfn;
 136
 137        last_pfn = (sp_banks[0].base_addr + sp_banks[0].num_bytes) >> PAGE_SHIFT;
 138        for (i = 1; sp_banks[i].num_bytes != 0; i++) {
 139                curr_pfn = sp_banks[i].base_addr >> PAGE_SHIFT;
 140
 141                if (curr_pfn >= tmp) {
 142                        if (last_pfn < tmp)
 143                                tmp = last_pfn;
 144                        break;
 145                }
 146
 147                last_pfn = (sp_banks[i].base_addr + sp_banks[i].num_bytes) >> PAGE_SHIFT;
 148        }
 149
 150        return tmp;
 151}
 152
 153unsigned long __init bootmem_init(unsigned long *pages_avail)
 154{
 155        unsigned long bootmap_size, start_pfn;
 156        unsigned long end_of_phys_memory = 0UL;
 157        unsigned long bootmap_pfn, bytes_avail, size;
 158        int i;
 159
 160        bytes_avail = 0UL;
 161        for (i = 0; sp_banks[i].num_bytes != 0; i++) {
 162                end_of_phys_memory = sp_banks[i].base_addr +
 163                        sp_banks[i].num_bytes;
 164                bytes_avail += sp_banks[i].num_bytes;
 165                if (cmdline_memory_size) {
 166                        if (bytes_avail > cmdline_memory_size) {
 167                                unsigned long slack = bytes_avail - cmdline_memory_size;
 168
 169                                bytes_avail -= slack;
 170                                end_of_phys_memory -= slack;
 171
 172                                sp_banks[i].num_bytes -= slack;
 173                                if (sp_banks[i].num_bytes == 0) {
 174                                        sp_banks[i].base_addr = 0xdeadbeef;
 175                                } else {
 176                                        sp_banks[i+1].num_bytes = 0;
 177                                        sp_banks[i+1].base_addr = 0xdeadbeef;
 178                                }
 179                                break;
 180                        }
 181                }
 182        }
 183
 184        /* Start with page aligned address of last symbol in kernel
 185         * image.  
 186         */
 187        start_pfn  = (unsigned long)__pa(PAGE_ALIGN((unsigned long) &_end));
 188
 189        /* Now shift down to get the real physical page frame number. */
 190        start_pfn >>= PAGE_SHIFT;
 191
 192        bootmap_pfn = start_pfn;
 193
 194        max_pfn = end_of_phys_memory >> PAGE_SHIFT;
 195
 196        max_low_pfn = max_pfn;
 197        highstart_pfn = highend_pfn = max_pfn;
 198
 199        if (max_low_pfn > pfn_base + (SRMMU_MAXMEM >> PAGE_SHIFT)) {
 200                highstart_pfn = pfn_base + (SRMMU_MAXMEM >> PAGE_SHIFT);
 201                max_low_pfn = calc_max_low_pfn();
 202                printk(KERN_NOTICE "%ldMB HIGHMEM available.\n",
 203                    calc_highpages() >> (20 - PAGE_SHIFT));
 204        }
 205
 206#ifdef CONFIG_BLK_DEV_INITRD
 207        /* Now have to check initial ramdisk, so that bootmap does not overwrite it */
 208        if (sparc_ramdisk_image) {
 209                if (sparc_ramdisk_image >= (unsigned long)&_end - 2 * PAGE_SIZE)
 210                        sparc_ramdisk_image -= KERNBASE;
 211                initrd_start = sparc_ramdisk_image + phys_base;
 212                initrd_end = initrd_start + sparc_ramdisk_size;
 213                if (initrd_end > end_of_phys_memory) {
 214                        printk(KERN_CRIT "initrd extends beyond end of memory "
 215                                         "(0x%016lx > 0x%016lx)\ndisabling initrd\n",
 216                               initrd_end, end_of_phys_memory);
 217                        initrd_start = 0;
 218                }
 219                if (initrd_start) {
 220                        if (initrd_start >= (start_pfn << PAGE_SHIFT) &&
 221                            initrd_start < (start_pfn << PAGE_SHIFT) + 2 * PAGE_SIZE)
 222                                bootmap_pfn = PAGE_ALIGN (initrd_end) >> PAGE_SHIFT;
 223                }
 224        }
 225#endif  
 226        /* Initialize the boot-time allocator. */
 227        bootmap_size = init_bootmem_node(NODE_DATA(0), bootmap_pfn, pfn_base,
 228                                         max_low_pfn);
 229
 230        /* Now register the available physical memory with the
 231         * allocator.
 232         */
 233        *pages_avail = 0;
 234        for (i = 0; sp_banks[i].num_bytes != 0; i++) {
 235                unsigned long curr_pfn, last_pfn;
 236
 237                curr_pfn = sp_banks[i].base_addr >> PAGE_SHIFT;
 238                if (curr_pfn >= max_low_pfn)
 239                        break;
 240
 241                last_pfn = (sp_banks[i].base_addr + sp_banks[i].num_bytes) >> PAGE_SHIFT;
 242                if (last_pfn > max_low_pfn)
 243                        last_pfn = max_low_pfn;
 244
 245                /*
 246                 * .. finally, did all the rounding and playing
 247                 * around just make the area go away?
 248                 */
 249                if (last_pfn <= curr_pfn)
 250                        continue;
 251
 252                size = (last_pfn - curr_pfn) << PAGE_SHIFT;
 253                *pages_avail += last_pfn - curr_pfn;
 254
 255                free_bootmem(sp_banks[i].base_addr, size);
 256        }
 257
 258#ifdef CONFIG_BLK_DEV_INITRD
 259        if (initrd_start) {
 260                /* Reserve the initrd image area. */
 261                size = initrd_end - initrd_start;
 262                reserve_bootmem(initrd_start, size);
 263                *pages_avail -= PAGE_ALIGN(size) >> PAGE_SHIFT;
 264
 265                initrd_start = (initrd_start - phys_base) + PAGE_OFFSET;
 266                initrd_end = (initrd_end - phys_base) + PAGE_OFFSET;            
 267        }
 268#endif
 269        /* Reserve the kernel text/data/bss. */
 270        size = (start_pfn << PAGE_SHIFT) - phys_base;
 271        reserve_bootmem(phys_base, size);
 272        *pages_avail -= PAGE_ALIGN(size) >> PAGE_SHIFT;
 273
 274        /* Reserve the bootmem map.   We do not account for it
 275         * in pages_avail because we will release that memory
 276         * in free_all_bootmem.
 277         */
 278        size = bootmap_size;
 279        reserve_bootmem((bootmap_pfn << PAGE_SHIFT), size);
 280        *pages_avail -= PAGE_ALIGN(size) >> PAGE_SHIFT;
 281
 282        return max_pfn;
 283}
 284
 285/*
 286 * check_pgt_cache
 287 *
 288 * This is called at the end of unmapping of VMA (zap_page_range),
 289 * to rescan the page cache for architecture specific things,
 290 * presumably something like sun4/sun4c PMEGs. Most architectures
 291 * define check_pgt_cache empty.
 292 *
 293 * We simply copy the 2.4 implementation for now.
 294 */
 295int pgt_cache_water[2] = { 25, 50 };
 296
 297void check_pgt_cache(void)
 298{
 299        do_check_pgt_cache(pgt_cache_water[0], pgt_cache_water[1]);
 300}
 301
 302/*
 303 * paging_init() sets up the page tables: We call the MMU specific
 304 * init routine based upon the Sun model type on the Sparc.
 305 *
 306 */
 307extern void sun4c_paging_init(void);
 308extern void srmmu_paging_init(void);
 309extern void device_scan(void);
 310
 311pgprot_t PAGE_SHARED __read_mostly;
 312EXPORT_SYMBOL(PAGE_SHARED);
 313
 314void __init paging_init(void)
 315{
 316        switch(sparc_cpu_model) {
 317        case sun4c:
 318        case sun4e:
 319        case sun4:
 320                sun4c_paging_init();
 321                sparc_unmapped_base = 0xe0000000;
 322                BTFIXUPSET_SETHI(sparc_unmapped_base, 0xe0000000);
 323                break;
 324        case sun4m:
 325        case sun4d:
 326                srmmu_paging_init();
 327                sparc_unmapped_base = 0x50000000;
 328                BTFIXUPSET_SETHI(sparc_unmapped_base, 0x50000000);
 329                break;
 330        default:
 331                prom_printf("paging_init: Cannot init paging on this Sparc\n");
 332                prom_printf("paging_init: sparc_cpu_model = %d\n", sparc_cpu_model);
 333                prom_printf("paging_init: Halting...\n");
 334                prom_halt();
 335        };
 336
 337        /* Initialize the protection map with non-constant, MMU dependent values. */
 338        protection_map[0] = PAGE_NONE;
 339        protection_map[1] = PAGE_READONLY;
 340        protection_map[2] = PAGE_COPY;
 341        protection_map[3] = PAGE_COPY;
 342        protection_map[4] = PAGE_READONLY;
 343        protection_map[5] = PAGE_READONLY;
 344        protection_map[6] = PAGE_COPY;
 345        protection_map[7] = PAGE_COPY;
 346        protection_map[8] = PAGE_NONE;
 347        protection_map[9] = PAGE_READONLY;
 348        protection_map[10] = PAGE_SHARED;
 349        protection_map[11] = PAGE_SHARED;
 350        protection_map[12] = PAGE_READONLY;
 351        protection_map[13] = PAGE_READONLY;
 352        protection_map[14] = PAGE_SHARED;
 353        protection_map[15] = PAGE_SHARED;
 354        btfixup();
 355        prom_build_devicetree();
 356        device_scan();
 357}
 358
 359struct cache_palias *sparc_aliases;
 360
 361static void __init taint_real_pages(void)
 362{
 363        int i;
 364
 365        for (i = 0; sp_banks[i].num_bytes; i++) {
 366                unsigned long start, end;
 367
 368                start = sp_banks[i].base_addr;
 369                end = start + sp_banks[i].num_bytes;
 370
 371                while (start < end) {
 372                        set_bit(start >> 20, sparc_valid_addr_bitmap);
 373                        start += PAGE_SIZE;
 374                }
 375        }
 376}
 377
 378void map_high_region(unsigned long start_pfn, unsigned long end_pfn)
 379{
 380        unsigned long tmp;
 381
 382#ifdef CONFIG_DEBUG_HIGHMEM
 383        printk("mapping high region %08lx - %08lx\n", start_pfn, end_pfn);
 384#endif
 385
 386        for (tmp = start_pfn; tmp < end_pfn; tmp++) {
 387                struct page *page = pfn_to_page(tmp);
 388
 389                ClearPageReserved(page);
 390                init_page_count(page);
 391                __free_page(page);
 392                totalhigh_pages++;
 393        }
 394}
 395
 396void __init mem_init(void)
 397{
 398        int codepages = 0;
 399        int datapages = 0;
 400        int initpages = 0; 
 401        int reservedpages = 0;
 402        int i;
 403
 404        if (PKMAP_BASE+LAST_PKMAP*PAGE_SIZE >= FIXADDR_START) {
 405                prom_printf("BUG: fixmap and pkmap areas overlap\n");
 406                prom_printf("pkbase: 0x%lx pkend: 0x%lx fixstart 0x%lx\n",
 407                       PKMAP_BASE,
 408                       (unsigned long)PKMAP_BASE+LAST_PKMAP*PAGE_SIZE,
 409                       FIXADDR_START);
 410                prom_printf("Please mail sparclinux@vger.kernel.org.\n");
 411                prom_halt();
 412        }
 413
 414
 415        /* Saves us work later. */
 416        memset((void *)&empty_zero_page, 0, PAGE_SIZE);
 417
 418        i = last_valid_pfn >> ((20 - PAGE_SHIFT) + 5);
 419        i += 1;
 420        sparc_valid_addr_bitmap = (unsigned long *)
 421                __alloc_bootmem(i << 2, SMP_CACHE_BYTES, 0UL);
 422
 423        if (sparc_valid_addr_bitmap == NULL) {
 424                prom_printf("mem_init: Cannot alloc valid_addr_bitmap.\n");
 425                prom_halt();
 426        }
 427        memset(sparc_valid_addr_bitmap, 0, i << 2);
 428
 429        taint_real_pages();
 430
 431        max_mapnr = last_valid_pfn - pfn_base;
 432        high_memory = __va(max_low_pfn << PAGE_SHIFT);
 433
 434        totalram_pages = free_all_bootmem();
 435
 436        for (i = 0; sp_banks[i].num_bytes != 0; i++) {
 437                unsigned long start_pfn = sp_banks[i].base_addr >> PAGE_SHIFT;
 438                unsigned long end_pfn = (sp_banks[i].base_addr + sp_banks[i].num_bytes) >> PAGE_SHIFT;
 439
 440                num_physpages += sp_banks[i].num_bytes >> PAGE_SHIFT;
 441
 442                if (end_pfn <= highstart_pfn)
 443                        continue;
 444
 445                if (start_pfn < highstart_pfn)
 446                        start_pfn = highstart_pfn;
 447
 448                map_high_region(start_pfn, end_pfn);
 449        }
 450        
 451        totalram_pages += totalhigh_pages;
 452
 453        codepages = (((unsigned long) &etext) - ((unsigned long)&_start));
 454        codepages = PAGE_ALIGN(codepages) >> PAGE_SHIFT;
 455        datapages = (((unsigned long) &edata) - ((unsigned long)&etext));
 456        datapages = PAGE_ALIGN(datapages) >> PAGE_SHIFT;
 457        initpages = (((unsigned long) &__init_end) - ((unsigned long) &__init_begin));
 458        initpages = PAGE_ALIGN(initpages) >> PAGE_SHIFT;
 459
 460        /* Ignore memory holes for the purpose of counting reserved pages */
 461        for (i=0; i < max_low_pfn; i++)
 462                if (test_bit(i >> (20 - PAGE_SHIFT), sparc_valid_addr_bitmap)
 463                    && PageReserved(pfn_to_page(i)))
 464                        reservedpages++;
 465
 466        printk(KERN_INFO "Memory: %luk/%luk available (%dk kernel code, %dk reserved, %dk data, %dk init, %ldk highmem)\n",
 467               (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
 468               num_physpages << (PAGE_SHIFT - 10),
 469               codepages << (PAGE_SHIFT-10),
 470               reservedpages << (PAGE_SHIFT - 10),
 471               datapages << (PAGE_SHIFT-10), 
 472               initpages << (PAGE_SHIFT-10),
 473               totalhigh_pages << (PAGE_SHIFT-10));
 474}
 475
 476void free_initmem (void)
 477{
 478        unsigned long addr;
 479
 480        addr = (unsigned long)(&__init_begin);
 481        for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
 482                struct page *p;
 483
 484                p = virt_to_page(addr);
 485
 486                ClearPageReserved(p);
 487                init_page_count(p);
 488                __free_page(p);
 489                totalram_pages++;
 490                num_physpages++;
 491        }
 492        printk (KERN_INFO "Freeing unused kernel memory: %dk freed\n", (&__init_end - &__init_begin) >> 10);
 493}
 494
 495#ifdef CONFIG_BLK_DEV_INITRD
 496void free_initrd_mem(unsigned long start, unsigned long end)
 497{
 498        if (start < end)
 499                printk (KERN_INFO "Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
 500        for (; start < end; start += PAGE_SIZE) {
 501                struct page *p = virt_to_page(start);
 502
 503                ClearPageReserved(p);
 504                init_page_count(p);
 505                __free_page(p);
 506                num_physpages++;
 507        }
 508}
 509#endif
 510
 511void sparc_flush_page_to_ram(struct page *page)
 512{
 513        unsigned long vaddr = (unsigned long)page_address(page);
 514
 515        if (vaddr)
 516                __flush_page_to_ram(vaddr);
 517}
 518