linux/arch/powerpc/kernel/setup_64.c
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   1/*
   2 * 
   3 * Common boot and setup code.
   4 *
   5 * Copyright (C) 2001 PPC64 Team, IBM Corp
   6 *
   7 *      This program is free software; you can redistribute it and/or
   8 *      modify it under the terms of the GNU General Public License
   9 *      as published by the Free Software Foundation; either version
  10 *      2 of the License, or (at your option) any later version.
  11 */
  12
  13#define DEBUG
  14
  15#include <linux/export.h>
  16#include <linux/string.h>
  17#include <linux/sched.h>
  18#include <linux/init.h>
  19#include <linux/kernel.h>
  20#include <linux/reboot.h>
  21#include <linux/delay.h>
  22#include <linux/initrd.h>
  23#include <linux/seq_file.h>
  24#include <linux/ioport.h>
  25#include <linux/console.h>
  26#include <linux/utsname.h>
  27#include <linux/tty.h>
  28#include <linux/root_dev.h>
  29#include <linux/notifier.h>
  30#include <linux/cpu.h>
  31#include <linux/unistd.h>
  32#include <linux/serial.h>
  33#include <linux/serial_8250.h>
  34#include <linux/bootmem.h>
  35#include <linux/pci.h>
  36#include <linux/lockdep.h>
  37#include <linux/memblock.h>
  38#include <linux/hugetlb.h>
  39#include <linux/memory.h>
  40#include <linux/nmi.h>
  41
  42#include <asm/io.h>
  43#include <asm/kdump.h>
  44#include <asm/prom.h>
  45#include <asm/processor.h>
  46#include <asm/pgtable.h>
  47#include <asm/smp.h>
  48#include <asm/elf.h>
  49#include <asm/machdep.h>
  50#include <asm/paca.h>
  51#include <asm/time.h>
  52#include <asm/cputable.h>
  53#include <asm/sections.h>
  54#include <asm/btext.h>
  55#include <asm/nvram.h>
  56#include <asm/setup.h>
  57#include <asm/rtas.h>
  58#include <asm/iommu.h>
  59#include <asm/serial.h>
  60#include <asm/cache.h>
  61#include <asm/page.h>
  62#include <asm/mmu.h>
  63#include <asm/firmware.h>
  64#include <asm/xmon.h>
  65#include <asm/udbg.h>
  66#include <asm/kexec.h>
  67#include <asm/mmu_context.h>
  68#include <asm/code-patching.h>
  69#include <asm/kvm_ppc.h>
  70#include <asm/hugetlb.h>
  71#include <asm/epapr_hcalls.h>
  72
  73#ifdef DEBUG
  74#define DBG(fmt...) udbg_printf(fmt)
  75#else
  76#define DBG(fmt...)
  77#endif
  78
  79int spinning_secondaries;
  80u64 ppc64_pft_size;
  81
  82/* Pick defaults since we might want to patch instructions
  83 * before we've read this from the device tree.
  84 */
  85struct ppc64_caches ppc64_caches = {
  86        .dline_size = 0x40,
  87        .log_dline_size = 6,
  88        .iline_size = 0x40,
  89        .log_iline_size = 6
  90};
  91EXPORT_SYMBOL_GPL(ppc64_caches);
  92
  93/*
  94 * These are used in binfmt_elf.c to put aux entries on the stack
  95 * for each elf executable being started.
  96 */
  97int dcache_bsize;
  98int icache_bsize;
  99int ucache_bsize;
 100
 101#if defined(CONFIG_PPC_BOOK3E) && defined(CONFIG_SMP)
 102static void setup_tlb_core_data(void)
 103{
 104        int cpu;
 105
 106        BUILD_BUG_ON(offsetof(struct tlb_core_data, lock) != 0);
 107
 108        for_each_possible_cpu(cpu) {
 109                int first = cpu_first_thread_sibling(cpu);
 110
 111                paca[cpu].tcd_ptr = &paca[first].tcd;
 112
 113                /*
 114                 * If we have threads, we need either tlbsrx.
 115                 * or e6500 tablewalk mode, or else TLB handlers
 116                 * will be racy and could produce duplicate entries.
 117                 */
 118                if (smt_enabled_at_boot >= 2 &&
 119                    !mmu_has_feature(MMU_FTR_USE_TLBRSRV) &&
 120                    book3e_htw_mode != PPC_HTW_E6500) {
 121                        /* Should we panic instead? */
 122                        WARN_ONCE("%s: unsupported MMU configuration -- expect problems\n",
 123                                  __func__);
 124                }
 125        }
 126}
 127#else
 128static void setup_tlb_core_data(void)
 129{
 130}
 131#endif
 132
 133#ifdef CONFIG_SMP
 134
 135static char *smt_enabled_cmdline;
 136
 137/* Look for ibm,smt-enabled OF option */
 138static void check_smt_enabled(void)
 139{
 140        struct device_node *dn;
 141        const char *smt_option;
 142
 143        /* Default to enabling all threads */
 144        smt_enabled_at_boot = threads_per_core;
 145
 146        /* Allow the command line to overrule the OF option */
 147        if (smt_enabled_cmdline) {
 148                if (!strcmp(smt_enabled_cmdline, "on"))
 149                        smt_enabled_at_boot = threads_per_core;
 150                else if (!strcmp(smt_enabled_cmdline, "off"))
 151                        smt_enabled_at_boot = 0;
 152                else {
 153                        int smt;
 154                        int rc;
 155
 156                        rc = kstrtoint(smt_enabled_cmdline, 10, &smt);
 157                        if (!rc)
 158                                smt_enabled_at_boot =
 159                                        min(threads_per_core, smt);
 160                }
 161        } else {
 162                dn = of_find_node_by_path("/options");
 163                if (dn) {
 164                        smt_option = of_get_property(dn, "ibm,smt-enabled",
 165                                                     NULL);
 166
 167                        if (smt_option) {
 168                                if (!strcmp(smt_option, "on"))
 169                                        smt_enabled_at_boot = threads_per_core;
 170                                else if (!strcmp(smt_option, "off"))
 171                                        smt_enabled_at_boot = 0;
 172                        }
 173
 174                        of_node_put(dn);
 175                }
 176        }
 177}
 178
 179/* Look for smt-enabled= cmdline option */
 180static int __init early_smt_enabled(char *p)
 181{
 182        smt_enabled_cmdline = p;
 183        return 0;
 184}
 185early_param("smt-enabled", early_smt_enabled);
 186
 187#else
 188#define check_smt_enabled()
 189#endif /* CONFIG_SMP */
 190
 191/** Fix up paca fields required for the boot cpu */
 192static void fixup_boot_paca(void)
 193{
 194        /* The boot cpu is started */
 195        get_paca()->cpu_start = 1;
 196        /* Allow percpu accesses to work until we setup percpu data */
 197        get_paca()->data_offset = 0;
 198}
 199
 200static void cpu_ready_for_interrupts(void)
 201{
 202        /* Set IR and DR in PACA MSR */
 203        get_paca()->kernel_msr = MSR_KERNEL;
 204
 205        /*
 206         * Enable AIL if supported, and we are in hypervisor mode. If we are
 207         * not in hypervisor mode, we enable relocation-on interrupts later
 208         * in pSeries_setup_arch() using the H_SET_MODE hcall.
 209         */
 210        if (cpu_has_feature(CPU_FTR_HVMODE) &&
 211            cpu_has_feature(CPU_FTR_ARCH_207S)) {
 212                unsigned long lpcr = mfspr(SPRN_LPCR);
 213                mtspr(SPRN_LPCR, lpcr | LPCR_AIL_3);
 214        }
 215}
 216
 217/*
 218 * Early initialization entry point. This is called by head.S
 219 * with MMU translation disabled. We rely on the "feature" of
 220 * the CPU that ignores the top 2 bits of the address in real
 221 * mode so we can access kernel globals normally provided we
 222 * only toy with things in the RMO region. From here, we do
 223 * some early parsing of the device-tree to setup out MEMBLOCK
 224 * data structures, and allocate & initialize the hash table
 225 * and segment tables so we can start running with translation
 226 * enabled.
 227 *
 228 * It is this function which will call the probe() callback of
 229 * the various platform types and copy the matching one to the
 230 * global ppc_md structure. Your platform can eventually do
 231 * some very early initializations from the probe() routine, but
 232 * this is not recommended, be very careful as, for example, the
 233 * device-tree is not accessible via normal means at this point.
 234 */
 235
 236void __init early_setup(unsigned long dt_ptr)
 237{
 238        static __initdata struct paca_struct boot_paca;
 239
 240        /* -------- printk is _NOT_ safe to use here ! ------- */
 241
 242        /* Identify CPU type */
 243        identify_cpu(0, mfspr(SPRN_PVR));
 244
 245        /* Assume we're on cpu 0 for now. Don't write to the paca yet! */
 246        initialise_paca(&boot_paca, 0);
 247        setup_paca(&boot_paca);
 248        fixup_boot_paca();
 249
 250        /* Initialize lockdep early or else spinlocks will blow */
 251        lockdep_init();
 252
 253        /* -------- printk is now safe to use ------- */
 254
 255        /* Enable early debugging if any specified (see udbg.h) */
 256        udbg_early_init();
 257
 258        DBG(" -> early_setup(), dt_ptr: 0x%lx\n", dt_ptr);
 259
 260        /*
 261         * Do early initialization using the flattened device
 262         * tree, such as retrieving the physical memory map or
 263         * calculating/retrieving the hash table size.
 264         */
 265        early_init_devtree(__va(dt_ptr));
 266
 267        epapr_paravirt_early_init();
 268
 269        /* Now we know the logical id of our boot cpu, setup the paca. */
 270        setup_paca(&paca[boot_cpuid]);
 271        fixup_boot_paca();
 272
 273        /* Probe the machine type */
 274        probe_machine();
 275
 276        setup_kdump_trampoline();
 277
 278        DBG("Found, Initializing memory management...\n");
 279
 280        /* Initialize the hash table or TLB handling */
 281        early_init_mmu();
 282
 283        /*
 284         * At this point, we can let interrupts switch to virtual mode
 285         * (the MMU has been setup), so adjust the MSR in the PACA to
 286         * have IR and DR set and enable AIL if it exists
 287         */
 288        cpu_ready_for_interrupts();
 289
 290        /* Reserve large chunks of memory for use by CMA for KVM */
 291        kvm_cma_reserve();
 292
 293        /*
 294         * Reserve any gigantic pages requested on the command line.
 295         * memblock needs to have been initialized by the time this is
 296         * called since this will reserve memory.
 297         */
 298        reserve_hugetlb_gpages();
 299
 300        DBG(" <- early_setup()\n");
 301
 302#ifdef CONFIG_PPC_EARLY_DEBUG_BOOTX
 303        /*
 304         * This needs to be done *last* (after the above DBG() even)
 305         *
 306         * Right after we return from this function, we turn on the MMU
 307         * which means the real-mode access trick that btext does will
 308         * no longer work, it needs to switch to using a real MMU
 309         * mapping. This call will ensure that it does
 310         */
 311        btext_map();
 312#endif /* CONFIG_PPC_EARLY_DEBUG_BOOTX */
 313}
 314
 315#ifdef CONFIG_SMP
 316void early_setup_secondary(void)
 317{
 318        /* Mark interrupts enabled in PACA */
 319        get_paca()->soft_enabled = 0;
 320
 321        /* Initialize the hash table or TLB handling */
 322        early_init_mmu_secondary();
 323
 324        /*
 325         * At this point, we can let interrupts switch to virtual mode
 326         * (the MMU has been setup), so adjust the MSR in the PACA to
 327         * have IR and DR set.
 328         */
 329        cpu_ready_for_interrupts();
 330}
 331
 332#endif /* CONFIG_SMP */
 333
 334#if defined(CONFIG_SMP) || defined(CONFIG_KEXEC)
 335void smp_release_cpus(void)
 336{
 337        unsigned long *ptr;
 338        int i;
 339
 340        DBG(" -> smp_release_cpus()\n");
 341
 342        /* All secondary cpus are spinning on a common spinloop, release them
 343         * all now so they can start to spin on their individual paca
 344         * spinloops. For non SMP kernels, the secondary cpus never get out
 345         * of the common spinloop.
 346         */
 347
 348        ptr  = (unsigned long *)((unsigned long)&__secondary_hold_spinloop
 349                        - PHYSICAL_START);
 350        *ptr = ppc_function_entry(generic_secondary_smp_init);
 351
 352        /* And wait a bit for them to catch up */
 353        for (i = 0; i < 100000; i++) {
 354                mb();
 355                HMT_low();
 356                if (spinning_secondaries == 0)
 357                        break;
 358                udelay(1);
 359        }
 360        DBG("spinning_secondaries = %d\n", spinning_secondaries);
 361
 362        DBG(" <- smp_release_cpus()\n");
 363}
 364#endif /* CONFIG_SMP || CONFIG_KEXEC */
 365
 366/*
 367 * Initialize some remaining members of the ppc64_caches and systemcfg
 368 * structures
 369 * (at least until we get rid of them completely). This is mostly some
 370 * cache informations about the CPU that will be used by cache flush
 371 * routines and/or provided to userland
 372 */
 373static void __init initialize_cache_info(void)
 374{
 375        struct device_node *np;
 376        unsigned long num_cpus = 0;
 377
 378        DBG(" -> initialize_cache_info()\n");
 379
 380        for_each_node_by_type(np, "cpu") {
 381                num_cpus += 1;
 382
 383                /*
 384                 * We're assuming *all* of the CPUs have the same
 385                 * d-cache and i-cache sizes... -Peter
 386                 */
 387                if (num_cpus == 1) {
 388                        const __be32 *sizep, *lsizep;
 389                        u32 size, lsize;
 390
 391                        size = 0;
 392                        lsize = cur_cpu_spec->dcache_bsize;
 393                        sizep = of_get_property(np, "d-cache-size", NULL);
 394                        if (sizep != NULL)
 395                                size = be32_to_cpu(*sizep);
 396                        lsizep = of_get_property(np, "d-cache-block-size",
 397                                                 NULL);
 398                        /* fallback if block size missing */
 399                        if (lsizep == NULL)
 400                                lsizep = of_get_property(np,
 401                                                         "d-cache-line-size",
 402                                                         NULL);
 403                        if (lsizep != NULL)
 404                                lsize = be32_to_cpu(*lsizep);
 405                        if (sizep == NULL || lsizep == NULL)
 406                                DBG("Argh, can't find dcache properties ! "
 407                                    "sizep: %p, lsizep: %p\n", sizep, lsizep);
 408
 409                        ppc64_caches.dsize = size;
 410                        ppc64_caches.dline_size = lsize;
 411                        ppc64_caches.log_dline_size = __ilog2(lsize);
 412                        ppc64_caches.dlines_per_page = PAGE_SIZE / lsize;
 413
 414                        size = 0;
 415                        lsize = cur_cpu_spec->icache_bsize;
 416                        sizep = of_get_property(np, "i-cache-size", NULL);
 417                        if (sizep != NULL)
 418                                size = be32_to_cpu(*sizep);
 419                        lsizep = of_get_property(np, "i-cache-block-size",
 420                                                 NULL);
 421                        if (lsizep == NULL)
 422                                lsizep = of_get_property(np,
 423                                                         "i-cache-line-size",
 424                                                         NULL);
 425                        if (lsizep != NULL)
 426                                lsize = be32_to_cpu(*lsizep);
 427                        if (sizep == NULL || lsizep == NULL)
 428                                DBG("Argh, can't find icache properties ! "
 429                                    "sizep: %p, lsizep: %p\n", sizep, lsizep);
 430
 431                        ppc64_caches.isize = size;
 432                        ppc64_caches.iline_size = lsize;
 433                        ppc64_caches.log_iline_size = __ilog2(lsize);
 434                        ppc64_caches.ilines_per_page = PAGE_SIZE / lsize;
 435                }
 436        }
 437
 438        DBG(" <- initialize_cache_info()\n");
 439}
 440
 441
 442/*
 443 * Do some initial setup of the system.  The parameters are those which 
 444 * were passed in from the bootloader.
 445 */
 446void __init setup_system(void)
 447{
 448        DBG(" -> setup_system()\n");
 449
 450        /* Apply the CPUs-specific and firmware specific fixups to kernel
 451         * text (nop out sections not relevant to this CPU or this firmware)
 452         */
 453        do_feature_fixups(cur_cpu_spec->cpu_features,
 454                          &__start___ftr_fixup, &__stop___ftr_fixup);
 455        do_feature_fixups(cur_cpu_spec->mmu_features,
 456                          &__start___mmu_ftr_fixup, &__stop___mmu_ftr_fixup);
 457        do_feature_fixups(powerpc_firmware_features,
 458                          &__start___fw_ftr_fixup, &__stop___fw_ftr_fixup);
 459        do_lwsync_fixups(cur_cpu_spec->cpu_features,
 460                         &__start___lwsync_fixup, &__stop___lwsync_fixup);
 461        do_final_fixups();
 462
 463        /*
 464         * Unflatten the device-tree passed by prom_init or kexec
 465         */
 466        unflatten_device_tree();
 467
 468        /*
 469         * Fill the ppc64_caches & systemcfg structures with informations
 470         * retrieved from the device-tree.
 471         */
 472        initialize_cache_info();
 473
 474#ifdef CONFIG_PPC_RTAS
 475        /*
 476         * Initialize RTAS if available
 477         */
 478        rtas_initialize();
 479#endif /* CONFIG_PPC_RTAS */
 480
 481        /*
 482         * Check if we have an initrd provided via the device-tree
 483         */
 484        check_for_initrd();
 485
 486        /*
 487         * Do some platform specific early initializations, that includes
 488         * setting up the hash table pointers. It also sets up some interrupt-mapping
 489         * related options that will be used by finish_device_tree()
 490         */
 491        if (ppc_md.init_early)
 492                ppc_md.init_early();
 493
 494        /*
 495         * We can discover serial ports now since the above did setup the
 496         * hash table management for us, thus ioremap works. We do that early
 497         * so that further code can be debugged
 498         */
 499        find_legacy_serial_ports();
 500
 501        /*
 502         * Register early console
 503         */
 504        register_early_udbg_console();
 505
 506        /*
 507         * Initialize xmon
 508         */
 509        xmon_setup();
 510
 511        smp_setup_cpu_maps();
 512        check_smt_enabled();
 513        setup_tlb_core_data();
 514
 515        /*
 516         * Freescale Book3e parts spin in a loop provided by firmware,
 517         * so smp_release_cpus() does nothing for them
 518         */
 519#if defined(CONFIG_SMP) && !defined(CONFIG_PPC_FSL_BOOK3E)
 520        /* Release secondary cpus out of their spinloops at 0x60 now that
 521         * we can map physical -> logical CPU ids
 522         */
 523        smp_release_cpus();
 524#endif
 525
 526        pr_info("Starting Linux PPC64 %s\n", init_utsname()->version);
 527
 528        pr_info("-----------------------------------------------------\n");
 529        pr_info("ppc64_pft_size    = 0x%llx\n", ppc64_pft_size);
 530        pr_info("phys_mem_size     = 0x%llx\n", memblock_phys_mem_size());
 531
 532        if (ppc64_caches.dline_size != 0x80)
 533                pr_info("dcache_line_size  = 0x%x\n", ppc64_caches.dline_size);
 534        if (ppc64_caches.iline_size != 0x80)
 535                pr_info("icache_line_size  = 0x%x\n", ppc64_caches.iline_size);
 536
 537        pr_info("cpu_features      = 0x%016lx\n", cur_cpu_spec->cpu_features);
 538        pr_info("  possible        = 0x%016lx\n", CPU_FTRS_POSSIBLE);
 539        pr_info("  always          = 0x%016lx\n", CPU_FTRS_ALWAYS);
 540        pr_info("cpu_user_features = 0x%08x 0x%08x\n", cur_cpu_spec->cpu_user_features,
 541                cur_cpu_spec->cpu_user_features2);
 542        pr_info("mmu_features      = 0x%08x\n", cur_cpu_spec->mmu_features);
 543        pr_info("firmware_features = 0x%016lx\n", powerpc_firmware_features);
 544
 545#ifdef CONFIG_PPC_STD_MMU_64
 546        if (htab_address)
 547                pr_info("htab_address      = 0x%p\n", htab_address);
 548
 549        pr_info("htab_hash_mask    = 0x%lx\n", htab_hash_mask);
 550#endif
 551
 552        if (PHYSICAL_START > 0)
 553                pr_info("physical_start    = 0x%llx\n",
 554                       (unsigned long long)PHYSICAL_START);
 555        pr_info("-----------------------------------------------------\n");
 556
 557        DBG(" <- setup_system()\n");
 558}
 559
 560/* This returns the limit below which memory accesses to the linear
 561 * mapping are guarnateed not to cause a TLB or SLB miss. This is
 562 * used to allocate interrupt or emergency stacks for which our
 563 * exception entry path doesn't deal with being interrupted.
 564 */
 565static u64 safe_stack_limit(void)
 566{
 567#ifdef CONFIG_PPC_BOOK3E
 568        /* Freescale BookE bolts the entire linear mapping */
 569        if (mmu_has_feature(MMU_FTR_TYPE_FSL_E))
 570                return linear_map_top;
 571        /* Other BookE, we assume the first GB is bolted */
 572        return 1ul << 30;
 573#else
 574        /* BookS, the first segment is bolted */
 575        if (mmu_has_feature(MMU_FTR_1T_SEGMENT))
 576                return 1UL << SID_SHIFT_1T;
 577        return 1UL << SID_SHIFT;
 578#endif
 579}
 580
 581static void __init irqstack_early_init(void)
 582{
 583        u64 limit = safe_stack_limit();
 584        unsigned int i;
 585
 586        /*
 587         * Interrupt stacks must be in the first segment since we
 588         * cannot afford to take SLB misses on them.
 589         */
 590        for_each_possible_cpu(i) {
 591                softirq_ctx[i] = (struct thread_info *)
 592                        __va(memblock_alloc_base(THREAD_SIZE,
 593                                            THREAD_SIZE, limit));
 594                hardirq_ctx[i] = (struct thread_info *)
 595                        __va(memblock_alloc_base(THREAD_SIZE,
 596                                            THREAD_SIZE, limit));
 597        }
 598}
 599
 600#ifdef CONFIG_PPC_BOOK3E
 601static void __init exc_lvl_early_init(void)
 602{
 603        unsigned int i;
 604        unsigned long sp;
 605
 606        for_each_possible_cpu(i) {
 607                sp = memblock_alloc(THREAD_SIZE, THREAD_SIZE);
 608                critirq_ctx[i] = (struct thread_info *)__va(sp);
 609                paca[i].crit_kstack = __va(sp + THREAD_SIZE);
 610
 611                sp = memblock_alloc(THREAD_SIZE, THREAD_SIZE);
 612                dbgirq_ctx[i] = (struct thread_info *)__va(sp);
 613                paca[i].dbg_kstack = __va(sp + THREAD_SIZE);
 614
 615                sp = memblock_alloc(THREAD_SIZE, THREAD_SIZE);
 616                mcheckirq_ctx[i] = (struct thread_info *)__va(sp);
 617                paca[i].mc_kstack = __va(sp + THREAD_SIZE);
 618        }
 619
 620        if (cpu_has_feature(CPU_FTR_DEBUG_LVL_EXC))
 621                patch_exception(0x040, exc_debug_debug_book3e);
 622}
 623#else
 624#define exc_lvl_early_init()
 625#endif
 626
 627/*
 628 * Stack space used when we detect a bad kernel stack pointer, and
 629 * early in SMP boots before relocation is enabled. Exclusive emergency
 630 * stack for machine checks.
 631 */
 632static void __init emergency_stack_init(void)
 633{
 634        u64 limit;
 635        unsigned int i;
 636
 637        /*
 638         * Emergency stacks must be under 256MB, we cannot afford to take
 639         * SLB misses on them. The ABI also requires them to be 128-byte
 640         * aligned.
 641         *
 642         * Since we use these as temporary stacks during secondary CPU
 643         * bringup, we need to get at them in real mode. This means they
 644         * must also be within the RMO region.
 645         */
 646        limit = min(safe_stack_limit(), ppc64_rma_size);
 647
 648        for_each_possible_cpu(i) {
 649                unsigned long sp;
 650                sp  = memblock_alloc_base(THREAD_SIZE, THREAD_SIZE, limit);
 651                sp += THREAD_SIZE;
 652                paca[i].emergency_sp = __va(sp);
 653
 654#ifdef CONFIG_PPC_BOOK3S_64
 655                /* emergency stack for machine check exception handling. */
 656                sp  = memblock_alloc_base(THREAD_SIZE, THREAD_SIZE, limit);
 657                sp += THREAD_SIZE;
 658                paca[i].mc_emergency_sp = __va(sp);
 659#endif
 660        }
 661}
 662
 663/*
 664 * Called into from start_kernel this initializes memblock, which is used
 665 * to manage page allocation until mem_init is called.
 666 */
 667void __init setup_arch(char **cmdline_p)
 668{
 669        *cmdline_p = boot_command_line;
 670
 671        /*
 672         * Set cache line size based on type of cpu as a default.
 673         * Systems with OF can look in the properties on the cpu node(s)
 674         * for a possibly more accurate value.
 675         */
 676        dcache_bsize = ppc64_caches.dline_size;
 677        icache_bsize = ppc64_caches.iline_size;
 678
 679        if (ppc_md.panic)
 680                setup_panic();
 681
 682        init_mm.start_code = (unsigned long)_stext;
 683        init_mm.end_code = (unsigned long) _etext;
 684        init_mm.end_data = (unsigned long) _edata;
 685        init_mm.brk = klimit;
 686#ifdef CONFIG_PPC_64K_PAGES
 687        init_mm.context.pte_frag = NULL;
 688#endif
 689        irqstack_early_init();
 690        exc_lvl_early_init();
 691        emergency_stack_init();
 692
 693        initmem_init();
 694
 695#ifdef CONFIG_DUMMY_CONSOLE
 696        conswitchp = &dummy_con;
 697#endif
 698
 699        if (ppc_md.setup_arch)
 700                ppc_md.setup_arch();
 701
 702        paging_init();
 703
 704        /* Initialize the MMU context management stuff */
 705        mmu_context_init();
 706
 707        /* Interrupt code needs to be 64K-aligned */
 708        if ((unsigned long)_stext & 0xffff)
 709                panic("Kernelbase not 64K-aligned (0x%lx)!\n",
 710                      (unsigned long)_stext);
 711}
 712
 713#ifdef CONFIG_SMP
 714#define PCPU_DYN_SIZE           ()
 715
 716static void * __init pcpu_fc_alloc(unsigned int cpu, size_t size, size_t align)
 717{
 718        return __alloc_bootmem_node(NODE_DATA(cpu_to_node(cpu)), size, align,
 719                                    __pa(MAX_DMA_ADDRESS));
 720}
 721
 722static void __init pcpu_fc_free(void *ptr, size_t size)
 723{
 724        free_bootmem(__pa(ptr), size);
 725}
 726
 727static int pcpu_cpu_distance(unsigned int from, unsigned int to)
 728{
 729        if (cpu_to_node(from) == cpu_to_node(to))
 730                return LOCAL_DISTANCE;
 731        else
 732                return REMOTE_DISTANCE;
 733}
 734
 735unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
 736EXPORT_SYMBOL(__per_cpu_offset);
 737
 738void __init setup_per_cpu_areas(void)
 739{
 740        const size_t dyn_size = PERCPU_MODULE_RESERVE + PERCPU_DYNAMIC_RESERVE;
 741        size_t atom_size;
 742        unsigned long delta;
 743        unsigned int cpu;
 744        int rc;
 745
 746        /*
 747         * Linear mapping is one of 4K, 1M and 16M.  For 4K, no need
 748         * to group units.  For larger mappings, use 1M atom which
 749         * should be large enough to contain a number of units.
 750         */
 751        if (mmu_linear_psize == MMU_PAGE_4K)
 752                atom_size = PAGE_SIZE;
 753        else
 754                atom_size = 1 << 20;
 755
 756        rc = pcpu_embed_first_chunk(0, dyn_size, atom_size, pcpu_cpu_distance,
 757                                    pcpu_fc_alloc, pcpu_fc_free);
 758        if (rc < 0)
 759                panic("cannot initialize percpu area (err=%d)", rc);
 760
 761        delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start;
 762        for_each_possible_cpu(cpu) {
 763                __per_cpu_offset[cpu] = delta + pcpu_unit_offsets[cpu];
 764                paca[cpu].data_offset = __per_cpu_offset[cpu];
 765        }
 766}
 767#endif
 768
 769#ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
 770unsigned long memory_block_size_bytes(void)
 771{
 772        if (ppc_md.memory_block_size)
 773                return ppc_md.memory_block_size();
 774
 775        return MIN_MEMORY_BLOCK_SIZE;
 776}
 777#endif
 778
 779#if defined(CONFIG_PPC_INDIRECT_PIO) || defined(CONFIG_PPC_INDIRECT_MMIO)
 780struct ppc_pci_io ppc_pci_io;
 781EXPORT_SYMBOL(ppc_pci_io);
 782#endif
 783
 784#ifdef CONFIG_HARDLOCKUP_DETECTOR
 785u64 hw_nmi_get_sample_period(int watchdog_thresh)
 786{
 787        return ppc_proc_freq * watchdog_thresh;
 788}
 789
 790/*
 791 * The hardlockup detector breaks PMU event based branches and is likely
 792 * to get false positives in KVM guests, so disable it by default.
 793 */
 794static int __init disable_hardlockup_detector(void)
 795{
 796        hardlockup_detector_disable();
 797
 798        return 0;
 799}
 800early_initcall(disable_hardlockup_detector);
 801#endif
 802