arch/arc/kernel/setup.c

   1 /*
   2  * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  */
   8
   9 #include <linux/seq_file.h>
  10 #include <linux/fs.h>
  11 #include <linux/delay.h>
  12 #include <linux/root_dev.h>
  13 #include <linux/clk.h>
  14 #include <linux/clk-provider.h>
  15 #include <linux/clocksource.h>
  16 #include <linux/console.h>
  17 #include <linux/module.h>
  18 #include <linux/cpu.h>
  19 #include <linux/of_fdt.h>
  20 #include <linux/of.h>
  21 #include <linux/cache.h>
  22 #include <asm/sections.h>
  23 #include <asm/arcregs.h>
  24 #include <asm/tlb.h>
  25 #include <asm/setup.h>
  26 #include <asm/page.h>
  27 #include <asm/irq.h>
  28 #include <asm/unwind.h>
  29 #include <asm/mach_desc.h>
  30 #include <asm/smp.h>
  31
  32 #define FIX_PTR(x)  __asm__ __volatile__(";" : "+r"(x))
  33
  34 unsigned int intr_to_DE_cnt;
  35
  36 /* Part of U-boot ABI: see head.S */
  37 int __initdata uboot_tag;
  38 char __initdata *uboot_arg;
  39
  40 const struct machine_desc *machine_desc;
  41
  42 struct task_struct *_current_task[NR_CPUS];     /* For stack switching */
  43
  44 struct cpuinfo_arc cpuinfo_arc700[NR_CPUS];
  45
  46 static const struct id_to_str arc_cpu_rel[] = {
  47 #ifdef CONFIG_ISA_ARCOMPACT
  48         { 0x34, "R4.10"},
  49         { 0x35, "R4.11"},
  50 #else
  51         { 0x51, "R2.0" },
  52         { 0x52, "R2.1" },
  53         { 0x53, "R3.0" },
  54         { 0x54, "R4.0" },
  55 #endif
  56         { 0x00, NULL   }
  57 };
  58
  59 static const struct id_to_str arc_cpu_nm[] = {
  60 #ifdef CONFIG_ISA_ARCOMPACT
  61         { 0x20, "ARC 600"   },
  62         { 0x30, "ARC 770"   },  /* 750 identified seperately */
  63 #else
  64         { 0x40, "ARC EM"  },
  65         { 0x50, "ARC HS38"  },
  66         { 0x54, "ARC HS48"  },
  67 #endif
  68         { 0x00, "Unknown"   }
  69 };
  70
  71 static void read_decode_ccm_bcr(struct cpuinfo_arc *cpu)
  72 {
  73         if (is_isa_arcompact()) {
  74                 struct bcr_iccm_arcompact iccm;
  75                 struct bcr_dccm_arcompact dccm;
  76
  77                 READ_BCR(ARC_REG_ICCM_BUILD, iccm);
  78                 if (iccm.ver) {
  79                         cpu->iccm.sz = 4096 << iccm.sz; /* 8K to 512K */
  80                         cpu->iccm.base_addr = iccm.base << 16;
  81                 }
  82
  83                 READ_BCR(ARC_REG_DCCM_BUILD, dccm);
  84                 if (dccm.ver) {
  85                         unsigned long base;
  86                         cpu->dccm.sz = 2048 << dccm.sz; /* 2K to 256K */
  87
  88                         base = read_aux_reg(ARC_REG_DCCM_BASE_BUILD);
  89                         cpu->dccm.base_addr = base & ~0xF;
  90                 }
  91         } else {
  92                 struct bcr_iccm_arcv2 iccm;
  93                 struct bcr_dccm_arcv2 dccm;
  94                 unsigned long region;
  95
  96                 READ_BCR(ARC_REG_ICCM_BUILD, iccm);
  97                 if (iccm.ver) {
  98                         cpu->iccm.sz = 256 << iccm.sz00;        /* 512B to 16M */
  99                         if (iccm.sz00 == 0xF && iccm.sz01 > 0)
 100                                 cpu->iccm.sz <<= iccm.sz01;
 101
 102                         region = read_aux_reg(ARC_REG_AUX_ICCM);
 103                         cpu->iccm.base_addr = region & 0xF0000000;
 104                 }
 105
 106                 READ_BCR(ARC_REG_DCCM_BUILD, dccm);
 107                 if (dccm.ver) {
 108                         cpu->dccm.sz = 256 << dccm.sz0;
 109                         if (dccm.sz0 == 0xF && dccm.sz1 > 0)
 110                                 cpu->dccm.sz <<= dccm.sz1;
 111
 112                         region = read_aux_reg(ARC_REG_AUX_DCCM);
 113                         cpu->dccm.base_addr = region & 0xF0000000;
 114                 }
 115         }
 116 }
 117
 118 static void read_arc_build_cfg_regs(void)
 119 {
 120         struct bcr_timer timer;
 121         struct bcr_generic bcr;
 122         struct cpuinfo_arc *cpu = &cpuinfo_arc700[smp_processor_id()];
 123         const struct id_to_str *tbl;
 124         struct bcr_isa_arcv2 isa;
 125
 126         FIX_PTR(cpu);
 127
 128         READ_BCR(AUX_IDENTITY, cpu->core);
 129
 130         for (tbl = &arc_cpu_rel[0]; tbl->id != 0; tbl++) {
 131                 if (cpu->core.family == tbl->id) {
 132                         cpu->details = tbl->str;
 133                         break;
 134                 }
 135         }
 136
 137         for (tbl = &arc_cpu_nm[0]; tbl->id != 0; tbl++) {
 138                 if ((cpu->core.family & 0xF4) == tbl->id)
 139                         break;
 140         }
 141         cpu->name = tbl->str;
 142
 143         READ_BCR(ARC_REG_TIMERS_BCR, timer);
 144         cpu->extn.timer0 = timer.t0;
 145         cpu->extn.timer1 = timer.t1;
 146         cpu->extn.rtc = timer.rtc;
 147
 148         cpu->vec_base = read_aux_reg(AUX_INTR_VEC_BASE);
 149
 150         READ_BCR(ARC_REG_MUL_BCR, cpu->extn_mpy);
 151
 152         cpu->extn.norm = read_aux_reg(ARC_REG_NORM_BCR) > 1 ? 1 : 0; /* 2,3 */
 153         cpu->extn.barrel = read_aux_reg(ARC_REG_BARREL_BCR) > 1 ? 1 : 0; /* 2,3 */
 154         cpu->extn.swap = read_aux_reg(ARC_REG_SWAP_BCR) ? 1 : 0;        /* 1,3 */
 155         cpu->extn.crc = read_aux_reg(ARC_REG_CRC_BCR) ? 1 : 0;
 156         cpu->extn.minmax = read_aux_reg(ARC_REG_MIXMAX_BCR) > 1 ? 1 : 0; /* 2 */
 157         cpu->extn.swape = (cpu->core.family >= 0x34) ? 1 :
 158                                 IS_ENABLED(CONFIG_ARC_HAS_SWAPE);
 159
 160         READ_BCR(ARC_REG_XY_MEM_BCR, cpu->extn_xymem);
 161
 162         /* Read CCM BCRs for boot reporting even if not enabled in Kconfig */
 163         read_decode_ccm_bcr(cpu);
 164
 165         read_decode_mmu_bcr();
 166         read_decode_cache_bcr();
 167
 168         if (is_isa_arcompact()) {
 169                 struct bcr_fp_arcompact sp, dp;
 170                 struct bcr_bpu_arcompact bpu;
 171
 172                 READ_BCR(ARC_REG_FP_BCR, sp);
 173                 READ_BCR(ARC_REG_DPFP_BCR, dp);
 174                 cpu->extn.fpu_sp = sp.ver ? 1 : 0;
 175                 cpu->extn.fpu_dp = dp.ver ? 1 : 0;
 176
 177                 READ_BCR(ARC_REG_BPU_BCR, bpu);
 178                 cpu->bpu.ver = bpu.ver;
 179                 cpu->bpu.full = bpu.fam ? 1 : 0;
 180                 if (bpu.ent) {
 181                         cpu->bpu.num_cache = 256 << (bpu.ent - 1);
 182                         cpu->bpu.num_pred = 256 << (bpu.ent - 1);
 183                 }
 184         } else {
 185                 struct bcr_fp_arcv2 spdp;
 186                 struct bcr_bpu_arcv2 bpu;
 187
 188                 READ_BCR(ARC_REG_FP_V2_BCR, spdp);
 189                 cpu->extn.fpu_sp = spdp.sp ? 1 : 0;
 190                 cpu->extn.fpu_dp = spdp.dp ? 1 : 0;
 191
 192                 READ_BCR(ARC_REG_BPU_BCR, bpu);
 193                 cpu->bpu.ver = bpu.ver;
 194                 cpu->bpu.full = bpu.ft;
 195                 cpu->bpu.num_cache = 256 << bpu.bce;
 196                 cpu->bpu.num_pred = 2048 << bpu.pte;
 197
 198                 if (cpu->core.family >= 0x54) {
 199                         unsigned int exec_ctrl;
 200
 201                         READ_BCR(AUX_EXEC_CTRL, exec_ctrl);
 202                         cpu->extn.dual_iss_exist = 1;
 203                         cpu->extn.dual_iss_enb = exec_ctrl & 1;
 204                 }
 205         }
 206
 207         READ_BCR(ARC_REG_AP_BCR, bcr);
 208         cpu->extn.ap = bcr.ver ? 1 : 0;
 209
 210         READ_BCR(ARC_REG_SMART_BCR, bcr);
 211         cpu->extn.smart = bcr.ver ? 1 : 0;
 212
 213         READ_BCR(ARC_REG_RTT_BCR, bcr);
 214         cpu->extn.rtt = bcr.ver ? 1 : 0;
 215
 216         cpu->extn.debug = cpu->extn.ap | cpu->extn.smart | cpu->extn.rtt;
 217
 218         READ_BCR(ARC_REG_ISA_CFG_BCR, isa);
 219
 220         /* some hacks for lack of feature BCR info in old ARC700 cores */
 221         if (is_isa_arcompact()) {
 222                 if (!isa.ver)   /* ISA BCR absent, use Kconfig info */
 223                         cpu->isa.atomic = IS_ENABLED(CONFIG_ARC_HAS_LLSC);
 224                 else {
 225                         /* ARC700_BUILD only has 2 bits of isa info */
 226                         struct bcr_generic bcr = *(struct bcr_generic *)&isa;
 227                         cpu->isa.atomic = bcr.info & 1;
 228                 }
 229
 230                 cpu->isa.be = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN);
 231
 232                  /* there's no direct way to distinguish 750 vs. 770 */
 233                 if (unlikely(cpu->core.family < 0x34 || cpu->mmu.ver < 3))
 234                         cpu->name = "ARC750";
 235         } else {
 236                 cpu->isa = isa;
 237         }
 238 }
 239
 240 static char *arc_cpu_mumbojumbo(int cpu_id, char *buf, int len)
 241 {
 242         struct cpuinfo_arc *cpu = &cpuinfo_arc700[cpu_id];
 243         struct bcr_identity *core = &cpu->core;
 244         int i, n = 0;
 245
 246         FIX_PTR(cpu);
 247
 248         n += scnprintf(buf + n, len - n,
 249                        "\nIDENTITY\t: ARCVER [%#02x] ARCNUM [%#02x] CHIPID [%#4x]\n",
 250                        core->family, core->cpu_id, core->chip_id);
 251
 252         n += scnprintf(buf + n, len - n, "processor [%d]\t: %s %s (%s ISA) %s%s%s\n",
 253                        cpu_id, cpu->name, cpu->details,
 254                        is_isa_arcompact() ? "ARCompact" : "ARCv2",
 255                        IS_AVAIL1(cpu->isa.be, "[Big-Endian]"),
 256                        IS_AVAIL3(cpu->extn.dual_iss_exist, cpu->extn.dual_iss_enb, " Dual-Issue"));
 257
 258         n += scnprintf(buf + n, len - n, "Timers\t\t: %s%s%s%s%s%s\nISA Extn\t: ",
 259                        IS_AVAIL1(cpu->extn.timer0, "Timer0 "),
 260                        IS_AVAIL1(cpu->extn.timer1, "Timer1 "),
 261                        IS_AVAIL2(cpu->extn.rtc, "RTC [UP 64-bit] ", CONFIG_ARC_TIMERS_64BIT),
 262                        IS_AVAIL2(cpu->extn.gfrc, "GFRC [SMP 64-bit] ", CONFIG_ARC_TIMERS_64BIT));
 263
 264         n += i = scnprintf(buf + n, len - n, "%s%s%s%s%s",
 265                            IS_AVAIL2(cpu->isa.atomic, "atomic ", CONFIG_ARC_HAS_LLSC),
 266                            IS_AVAIL2(cpu->isa.ldd, "ll64 ", CONFIG_ARC_HAS_LL64),
 267                            IS_AVAIL1(cpu->isa.unalign, "unalign (not used)"));
 268
 269         if (i)
 270                 n += scnprintf(buf + n, len - n, "\n\t\t: ");
 271
 272         if (cpu->extn_mpy.ver) {
 273                 if (cpu->extn_mpy.ver <= 0x2) { /* ARCompact */
 274                         n += scnprintf(buf + n, len - n, "mpy ");
 275                 } else {
 276                         int opt = 2;    /* stock MPY/MPYH */
 277
 278                         if (cpu->extn_mpy.dsp)  /* OPT 7-9 */
 279                                 opt = cpu->extn_mpy.dsp + 6;
 280
 281                         n += scnprintf(buf + n, len - n, "mpy[opt %d] ", opt);
 282                 }
 283         }
 284
 285         n += scnprintf(buf + n, len - n, "%s%s%s%s%s%s%s%s\n",
 286                        IS_AVAIL1(cpu->isa.div_rem, "div_rem "),
 287                        IS_AVAIL1(cpu->extn.norm, "norm "),
 288                        IS_AVAIL1(cpu->extn.barrel, "barrel-shift "),
 289                        IS_AVAIL1(cpu->extn.swap, "swap "),
 290                        IS_AVAIL1(cpu->extn.minmax, "minmax "),
 291                        IS_AVAIL1(cpu->extn.crc, "crc "),
 292                        IS_AVAIL2(cpu->extn.swape, "swape", CONFIG_ARC_HAS_SWAPE));
 293
 294         if (cpu->bpu.ver)
 295                 n += scnprintf(buf + n, len - n,
 296                               "BPU\t\t: %s%s match, cache:%d, Predict Table:%d\n",
 297                               IS_AVAIL1(cpu->bpu.full, "full"),
 298                               IS_AVAIL1(!cpu->bpu.full, "partial"),
 299                               cpu->bpu.num_cache, cpu->bpu.num_pred);
 300
 301         return buf;
 302 }
 303
 304 static char *arc_extn_mumbojumbo(int cpu_id, char *buf, int len)
 305 {
 306         int n = 0;
 307         struct cpuinfo_arc *cpu = &cpuinfo_arc700[cpu_id];
 308
 309         FIX_PTR(cpu);
 310
 311         n += scnprintf(buf + n, len - n, "Vector Table\t: %#x\n", cpu->vec_base);
 312
 313         if (cpu->extn.fpu_sp || cpu->extn.fpu_dp)
 314                 n += scnprintf(buf + n, len - n, "FPU\t\t: %s%s\n",
 315                                IS_AVAIL1(cpu->extn.fpu_sp, "SP "),
 316                                IS_AVAIL1(cpu->extn.fpu_dp, "DP "));
 317
 318         if (cpu->extn.debug)
 319                 n += scnprintf(buf + n, len - n, "DEBUG\t\t: %s%s%s\n",
 320                                IS_AVAIL1(cpu->extn.ap, "ActionPoint "),
 321                                IS_AVAIL1(cpu->extn.smart, "smaRT "),
 322                                IS_AVAIL1(cpu->extn.rtt, "RTT "));
 323
 324         if (cpu->dccm.sz || cpu->iccm.sz)
 325                 n += scnprintf(buf + n, len - n, "Extn [CCM]\t: DCCM @ %x, %d KB / ICCM: @ %x, %d KB\n",
 326                                cpu->dccm.base_addr, TO_KB(cpu->dccm.sz),
 327                                cpu->iccm.base_addr, TO_KB(cpu->iccm.sz));
 328
 329         n += scnprintf(buf + n, len - n, "OS ABI [v%d]\t: %s\n",
 330                         EF_ARC_OSABI_CURRENT >> 8,
 331                         EF_ARC_OSABI_CURRENT == EF_ARC_OSABI_V3 ?
 332                         "no-legacy-syscalls" : "64-bit data any register aligned");
 333
 334         return buf;
 335 }
 336
 337 static void arc_chk_core_config(void)
 338 {
 339         struct cpuinfo_arc *cpu = &cpuinfo_arc700[smp_processor_id()];
 340         int saved = 0, present = 0;
 341         char *opt_nm = NULL;;
 342
 343         if (!cpu->extn.timer0)
 344                 panic("Timer0 is not present!\n");
 345
 346         if (!cpu->extn.timer1)
 347                 panic("Timer1 is not present!\n");
 348
 349 #ifdef CONFIG_ARC_HAS_DCCM
 350         /*
 351          * DCCM can be arbit placed in hardware.
 352          * Make sure it's placement/sz matches what Linux is built with
 353          */
 354         if ((unsigned int)__arc_dccm_base != cpu->dccm.base_addr)
 355                 panic("Linux built with incorrect DCCM Base address\n");
 356
 357         if (CONFIG_ARC_DCCM_SZ != cpu->dccm.sz)
 358                 panic("Linux built with incorrect DCCM Size\n");
 359 #endif
 360
 361 #ifdef CONFIG_ARC_HAS_ICCM
 362         if (CONFIG_ARC_ICCM_SZ != cpu->iccm.sz)
 363                 panic("Linux built with incorrect ICCM Size\n");
 364 #endif
 365
 366         /*
 367          * FP hardware/software config sanity
 368          * -If hardware present, kernel needs to save/restore FPU state
 369          * -If not, it will crash trying to save/restore the non-existant regs
 370          */
 371
 372         if (is_isa_arcompact()) {
 373                 opt_nm = "CONFIG_ARC_FPU_SAVE_RESTORE";
 374                 saved = IS_ENABLED(CONFIG_ARC_FPU_SAVE_RESTORE);
 375
 376                 /* only DPDP checked since SP has no arch visible regs */
 377                 present = cpu->extn.fpu_dp;
 378         } else {
 379                 opt_nm = "CONFIG_ARC_HAS_ACCL_REGS";
 380                 saved = IS_ENABLED(CONFIG_ARC_HAS_ACCL_REGS);
 381
 382                 /* Accumulator Low:High pair (r58:59) present if DSP MPY or FPU */
 383                 present = cpu->extn_mpy.dsp | cpu->extn.fpu_sp | cpu->extn.fpu_dp;
 384         }
 385
 386         if (present && !saved)
 387                 pr_warn("Enable %s for working apps\n", opt_nm);
 388         else if (!present && saved)
 389                 panic("Disable %s, hardware NOT present\n", opt_nm);
 390 }
 391
 392 /*
 393  * Initialize and setup the processor core
 394  * This is called by all the CPUs thus should not do special case stuff
 395  *    such as only for boot CPU etc
 396  */
 397
 398 void setup_processor(void)
 399 {
 400         char str[512];
 401         int cpu_id = smp_processor_id();
 402
 403         read_arc_build_cfg_regs();
 404         arc_init_IRQ();
 405
 406         pr_info("%s", arc_cpu_mumbojumbo(cpu_id, str, sizeof(str)));
 407
 408         arc_mmu_init();
 409         arc_cache_init();
 410
 411         pr_info("%s", arc_extn_mumbojumbo(cpu_id, str, sizeof(str)));
 412         pr_info("%s", arc_platform_smp_cpuinfo());
 413
 414         arc_chk_core_config();
 415 }
 416
 417 static inline int is_kernel(unsigned long addr)
 418 {
 419         if (addr >= (unsigned long)_stext && addr <= (unsigned long)_end)
 420                 return 1;
 421         return 0;
 422 }
 423
 424 void __init setup_arch(char **cmdline_p)
 425 {
 426 #ifdef CONFIG_ARC_UBOOT_SUPPORT
 427         /* make sure that uboot passed pointer to cmdline/dtb is valid */
 428         if (uboot_tag && is_kernel((unsigned long)uboot_arg))
 429                 panic("Invalid uboot arg\n");
 430
 431         /* See if u-boot passed an external Device Tree blob */
 432         machine_desc = setup_machine_fdt(uboot_arg);    /* uboot_tag == 2 */
 433         if (!machine_desc)
 434 #endif
 435         {
 436                 /* No, so try the embedded one */
 437                 machine_desc = setup_machine_fdt(__dtb_start);
 438                 if (!machine_desc)
 439                         panic("Embedded DT invalid\n");
 440
 441                 /*
 442                  * If we are here, it is established that @uboot_arg didn't
 443                  * point to DT blob. Instead if u-boot says it is cmdline,
 444                  * append to embedded DT cmdline.
 445                  * setup_machine_fdt() would have populated @boot_command_line
 446                  */
 447                 if (uboot_tag == 1) {
 448                         /* Ensure a whitespace between the 2 cmdlines */
 449                         strlcat(boot_command_line, " ", COMMAND_LINE_SIZE);
 450                         strlcat(boot_command_line, uboot_arg,
 451                                 COMMAND_LINE_SIZE);
 452                 }
 453         }
 454
 455         /* Save unparsed command line copy for /proc/cmdline */
 456         *cmdline_p = boot_command_line;
 457
 458         /* To force early parsing of things like mem=xxx */
 459         parse_early_param();
 460
 461         /* Platform/board specific: e.g. early console registration */
 462         if (machine_desc->init_early)
 463                 machine_desc->init_early();
 464
 465         smp_init_cpus();
 466
 467         setup_processor();
 468         setup_arch_memory();
 469
 470         /* copy flat DT out of .init and then unflatten it */
 471         unflatten_and_copy_device_tree();
 472
 473         /* Can be issue if someone passes cmd line arg "ro"
 474          * But that is unlikely so keeping it as it is
 475          */
 476         root_mountflags &= ~MS_RDONLY;
 477
 478 #if defined(CONFIG_VT) && defined(CONFIG_DUMMY_CONSOLE)
 479         conswitchp = &dummy_con;
 480 #endif
 481
 482         arc_unwind_init();
 483 }
 484
 485 /*
 486  * Called from start_kernel() - boot CPU only
 487  */
 488 void __init time_init(void)
 489 {
 490         of_clk_init(NULL);
 491         timer_probe();
 492 }
 493
 494 static int __init customize_machine(void)
 495 {
 496         if (machine_desc->init_machine)
 497                 machine_desc->init_machine();
 498
 499         return 0;
 500 }
 501 arch_initcall(customize_machine);
 502
 503 static int __init init_late_machine(void)
 504 {
 505         if (machine_desc->init_late)
 506                 machine_desc->init_late();
 507
 508         return 0;
 509 }
 510 late_initcall(init_late_machine);
 511 /*
 512  *  Get CPU information for use by the procfs.
 513  */
 514
 515 #define cpu_to_ptr(c)   ((void *)(0xFFFF0000 | (unsigned int)(c)))
 516 #define ptr_to_cpu(p)   (~0xFFFF0000UL & (unsigned int)(p))
 517
 518 static int show_cpuinfo(struct seq_file *m, void *v)
 519 {
 520         char *str;
 521         int cpu_id = ptr_to_cpu(v);
 522         struct device *cpu_dev = get_cpu_device(cpu_id);
 523         struct clk *cpu_clk;
 524         unsigned long freq = 0;
 525
 526         if (!cpu_online(cpu_id)) {
 527                 seq_printf(m, "processor [%d]\t: Offline\n", cpu_id);
 528                 goto done;
 529         }
 530
 531         str = (char *)__get_free_page(GFP_KERNEL);
 532         if (!str)
 533                 goto done;
 534
 535         seq_printf(m, arc_cpu_mumbojumbo(cpu_id, str, PAGE_SIZE));
 536
 537         cpu_clk = clk_get(cpu_dev, NULL);
 538         if (IS_ERR(cpu_clk)) {
 539                 seq_printf(m, "CPU speed \t: Cannot get clock for processor [%d]\n",
 540                            cpu_id);
 541         } else {
 542                 freq = clk_get_rate(cpu_clk);
 543         }
 544         if (freq)
 545                 seq_printf(m, "CPU speed\t: %lu.%02lu Mhz\n",
 546                            freq / 1000000, (freq / 10000) % 100);
 547
 548         seq_printf(m, "Bogo MIPS\t: %lu.%02lu\n",
 549                    loops_per_jiffy / (500000 / HZ),
 550                    (loops_per_jiffy / (5000 / HZ)) % 100);
 551
 552         seq_printf(m, arc_mmu_mumbojumbo(cpu_id, str, PAGE_SIZE));
 553         seq_printf(m, arc_cache_mumbojumbo(cpu_id, str, PAGE_SIZE));
 554         seq_printf(m, arc_extn_mumbojumbo(cpu_id, str, PAGE_SIZE));
 555         seq_printf(m, arc_platform_smp_cpuinfo());
 556
 557         free_page((unsigned long)str);
 558 done:
 559         seq_printf(m, "\n");
 560
 561         return 0;
 562 }
 563
 564 static void *c_start(struct seq_file *m, loff_t *pos)
 565 {
 566         /*
 567          * Callback returns cpu-id to iterator for show routine, NULL to stop.
 568          * However since NULL is also a valid cpu-id (0), we use a round-about
 569          * way to pass it w/o having to kmalloc/free a 2 byte string.
 570          * Encode cpu-id as 0xFFcccc, which is decoded by show routine.
 571          */
 572         return *pos < nr_cpu_ids ? cpu_to_ptr(*pos) : NULL;
 573 }
 574
 575 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
 576 {
 577         ++*pos;
 578         return c_start(m, pos);
 579 }
 580
 581 static void c_stop(struct seq_file *m, void *v)
 582 {
 583 }
 584
 585 const struct seq_operations cpuinfo_op = {
 586         .start  = c_start,
 587         .next   = c_next,
 588         .stop   = c_stop,
 589         .show   = show_cpuinfo
 590 };
 591
 592 static DEFINE_PER_CPU(struct cpu, cpu_topology);
 593
 594 static int __init topology_init(void)
 595 {
 596         int cpu;
 597
 598         for_each_present_cpu(cpu)
 599             register_cpu(&per_cpu(cpu_topology, cpu), cpu);
 600
 601         return 0;
 602 }
 603
 604 subsys_initcall(topology_init);