arch/sparc/kernel/time_64.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* time.c: UltraSparc timer and TOD clock support.
   3  *
   4  * Copyright (C) 1997, 2008 David S. Miller (davem@davemloft.net)
   5  * Copyright (C) 1998 Eddie C. Dost   (ecd@skynet.be)
   6  *
   7  * Based largely on code which is:
   8  *
   9  * Copyright (C) 1996 Thomas K. Dyas (tdyas@eden.rutgers.edu)
  10  */
  11
  12 #include <linux/errno.h>
  13 #include <linux/export.h>
  14 #include <linux/sched.h>
  15 #include <linux/kernel.h>
  16 #include <linux/param.h>
  17 #include <linux/string.h>
  18 #include <linux/mm.h>
  19 #include <linux/interrupt.h>
  20 #include <linux/time.h>
  21 #include <linux/timex.h>
  22 #include <linux/init.h>
  23 #include <linux/ioport.h>
  24 #include <linux/mc146818rtc.h>
  25 #include <linux/delay.h>
  26 #include <linux/profile.h>
  27 #include <linux/bcd.h>
  28 #include <linux/jiffies.h>
  29 #include <linux/cpufreq.h>
  30 #include <linux/percpu.h>
  31 #include <linux/rtc/m48t59.h>
  32 #include <linux/kernel_stat.h>
  33 #include <linux/clockchips.h>
  34 #include <linux/clocksource.h>
  35 #include <linux/platform_device.h>
  36 #include <linux/sched/clock.h>
  37 #include <linux/ftrace.h>
  38
  39 #include <asm/oplib.h>
  40 #include <asm/timer.h>
  41 #include <asm/irq.h>
  42 #include <asm/io.h>
  43 #include <asm/prom.h>
  44 #include <asm/starfire.h>
  45 #include <asm/smp.h>
  46 #include <asm/sections.h>
  47 #include <asm/cpudata.h>
  48 #include <linux/uaccess.h>
  49 #include <asm/irq_regs.h>
  50 #include <asm/cacheflush.h>
  51
  52 #include "entry.h"
  53 #include "kernel.h"
  54
  55 DEFINE_SPINLOCK(rtc_lock);
  56
  57 #ifdef CONFIG_SMP
  58 unsigned long profile_pc(struct pt_regs *regs)
  59 {
  60         unsigned long pc = instruction_pointer(regs);
  61
  62         if (in_lock_functions(pc))
  63                 return regs->u_regs[UREG_RETPC];
  64         return pc;
  65 }
  66 EXPORT_SYMBOL(profile_pc);
  67 #endif
  68
  69 static void tick_disable_protection(void)
  70 {
  71         /* Set things up so user can access tick register for profiling
  72          * purposes.  Also workaround BB_ERRATA_1 by doing a dummy
  73          * read back of %tick after writing it.
  74          */
  75         __asm__ __volatile__(
  76         "       ba,pt   %%xcc, 1f\n"
  77         "        nop\n"
  78         "       .align  64\n"
  79         "1:     rd      %%tick, %%g2\n"
  80         "       add     %%g2, 6, %%g2\n"
  81         "       andn    %%g2, %0, %%g2\n"
  82         "       wrpr    %%g2, 0, %%tick\n"
  83         "       rdpr    %%tick, %%g0"
  84         : /* no outputs */
  85         : "r" (TICK_PRIV_BIT)
  86         : "g2");
  87 }
  88
  89 static void tick_disable_irq(void)
  90 {
  91         __asm__ __volatile__(
  92         "       ba,pt   %%xcc, 1f\n"
  93         "        nop\n"
  94         "       .align  64\n"
  95         "1:     wr      %0, 0x0, %%tick_cmpr\n"
  96         "       rd      %%tick_cmpr, %%g0"
  97         : /* no outputs */
  98         : "r" (TICKCMP_IRQ_BIT));
  99 }
 100
 101 static void tick_init_tick(void)
 102 {
 103         tick_disable_protection();
 104         tick_disable_irq();
 105 }
 106
 107 static unsigned long long tick_get_tick(void)
 108 {
 109         unsigned long ret;
 110
 111         __asm__ __volatile__("rd        %%tick, %0\n\t"
 112                              "mov       %0, %0"
 113                              : "=r" (ret));
 114
 115         return ret & ~TICK_PRIV_BIT;
 116 }
 117
 118 static int tick_add_compare(unsigned long adj)
 119 {
 120         unsigned long orig_tick, new_tick, new_compare;
 121
 122         __asm__ __volatile__("rd        %%tick, %0"
 123                              : "=r" (orig_tick));
 124
 125         orig_tick &= ~TICKCMP_IRQ_BIT;
 126
 127         /* Workaround for Spitfire Errata (#54 I think??), I discovered
 128          * this via Sun BugID 4008234, mentioned in Solaris-2.5.1 patch
 129          * number 103640.
 130          *
 131          * On Blackbird writes to %tick_cmpr can fail, the
 132          * workaround seems to be to execute the wr instruction
 133          * at the start of an I-cache line, and perform a dummy
 134          * read back from %tick_cmpr right after writing to it. -DaveM
 135          */
 136         __asm__ __volatile__("ba,pt     %%xcc, 1f\n\t"
 137                              " add      %1, %2, %0\n\t"
 138                              ".align    64\n"
 139                              "1:\n\t"
 140                              "wr        %0, 0, %%tick_cmpr\n\t"
 141                              "rd        %%tick_cmpr, %%g0\n\t"
 142                              : "=r" (new_compare)
 143                              : "r" (orig_tick), "r" (adj));
 144
 145         __asm__ __volatile__("rd        %%tick, %0"
 146                              : "=r" (new_tick));
 147         new_tick &= ~TICKCMP_IRQ_BIT;
 148
 149         return ((long)(new_tick - (orig_tick+adj))) > 0L;
 150 }
 151
 152 static unsigned long tick_add_tick(unsigned long adj)
 153 {
 154         unsigned long new_tick;
 155
 156         /* Also need to handle Blackbird bug here too. */
 157         __asm__ __volatile__("rd        %%tick, %0\n\t"
 158                              "add       %0, %1, %0\n\t"
 159                              "wrpr      %0, 0, %%tick\n\t"
 160                              : "=&r" (new_tick)
 161                              : "r" (adj));
 162
 163         return new_tick;
 164 }
 165
 166 /* Searches for cpu clock frequency with given cpuid in OpenBoot tree */
 167 static unsigned long cpuid_to_freq(phandle node, int cpuid)
 168 {
 169         bool is_cpu_node = false;
 170         unsigned long freq = 0;
 171         char type[128];
 172
 173         if (!node)
 174                 return freq;
 175
 176         if (prom_getproperty(node, "device_type", type, sizeof(type)) != -1)
 177                 is_cpu_node = (strcmp(type, "cpu") == 0);
 178
 179         /* try upa-portid then cpuid to get cpuid, see prom_64.c */
 180         if (is_cpu_node && (prom_getint(node, "upa-portid") == cpuid ||
 181                             prom_getint(node, "cpuid") == cpuid))
 182                 freq = prom_getintdefault(node, "clock-frequency", 0);
 183         if (!freq)
 184                 freq = cpuid_to_freq(prom_getchild(node), cpuid);
 185         if (!freq)
 186                 freq = cpuid_to_freq(prom_getsibling(node), cpuid);
 187
 188         return freq;
 189 }
 190
 191 static unsigned long tick_get_frequency(void)
 192 {
 193         return cpuid_to_freq(prom_root_node, hard_smp_processor_id());
 194 }
 195
 196 static struct sparc64_tick_ops tick_operations __cacheline_aligned = {
 197         .name           =       "tick",
 198         .init_tick      =       tick_init_tick,
 199         .disable_irq    =       tick_disable_irq,
 200         .get_tick       =       tick_get_tick,
 201         .add_tick       =       tick_add_tick,
 202         .add_compare    =       tick_add_compare,
 203         .get_frequency  =       tick_get_frequency,
 204         .softint_mask   =       1UL << 0,
 205 };
 206
 207 struct sparc64_tick_ops *tick_ops __read_mostly = &tick_operations;
 208 EXPORT_SYMBOL(tick_ops);
 209
 210 static void stick_disable_irq(void)
 211 {
 212         __asm__ __volatile__(
 213         "wr     %0, 0x0, %%asr25"
 214         : /* no outputs */
 215         : "r" (TICKCMP_IRQ_BIT));
 216 }
 217
 218 static void stick_init_tick(void)
 219 {
 220         /* Writes to the %tick and %stick register are not
 221          * allowed on sun4v.  The Hypervisor controls that
 222          * bit, per-strand.
 223          */
 224         if (tlb_type != hypervisor) {
 225                 tick_disable_protection();
 226                 tick_disable_irq();
 227
 228                 /* Let the user get at STICK too. */
 229                 __asm__ __volatile__(
 230                 "       rd      %%asr24, %%g2\n"
 231                 "       andn    %%g2, %0, %%g2\n"
 232                 "       wr      %%g2, 0, %%asr24"
 233                 : /* no outputs */
 234                 : "r" (TICK_PRIV_BIT)
 235                 : "g1", "g2");
 236         }
 237
 238         stick_disable_irq();
 239 }
 240
 241 static unsigned long long stick_get_tick(void)
 242 {
 243         unsigned long ret;
 244
 245         __asm__ __volatile__("rd        %%asr24, %0"
 246                              : "=r" (ret));
 247
 248         return ret & ~TICK_PRIV_BIT;
 249 }
 250
 251 static unsigned long stick_add_tick(unsigned long adj)
 252 {
 253         unsigned long new_tick;
 254
 255         __asm__ __volatile__("rd        %%asr24, %0\n\t"
 256                              "add       %0, %1, %0\n\t"
 257                              "wr        %0, 0, %%asr24\n\t"
 258                              : "=&r" (new_tick)
 259                              : "r" (adj));
 260
 261         return new_tick;
 262 }
 263
 264 static int stick_add_compare(unsigned long adj)
 265 {
 266         unsigned long orig_tick, new_tick;
 267
 268         __asm__ __volatile__("rd        %%asr24, %0"
 269                              : "=r" (orig_tick));
 270         orig_tick &= ~TICKCMP_IRQ_BIT;
 271
 272         __asm__ __volatile__("wr        %0, 0, %%asr25"
 273                              : /* no outputs */
 274                              : "r" (orig_tick + adj));
 275
 276         __asm__ __volatile__("rd        %%asr24, %0"
 277                              : "=r" (new_tick));
 278         new_tick &= ~TICKCMP_IRQ_BIT;
 279
 280         return ((long)(new_tick - (orig_tick+adj))) > 0L;
 281 }
 282
 283 static unsigned long stick_get_frequency(void)
 284 {
 285         return prom_getintdefault(prom_root_node, "stick-frequency", 0);
 286 }
 287
 288 static struct sparc64_tick_ops stick_operations __read_mostly = {
 289         .name           =       "stick",
 290         .init_tick      =       stick_init_tick,
 291         .disable_irq    =       stick_disable_irq,
 292         .get_tick       =       stick_get_tick,
 293         .add_tick       =       stick_add_tick,
 294         .add_compare    =       stick_add_compare,
 295         .get_frequency  =       stick_get_frequency,
 296         .softint_mask   =       1UL << 16,
 297 };
 298
 299 /* On Hummingbird the STICK/STICK_CMPR register is implemented
 300  * in I/O space.  There are two 64-bit registers each, the
 301  * first holds the low 32-bits of the value and the second holds
 302  * the high 32-bits.
 303  *
 304  * Since STICK is constantly updating, we have to access it carefully.
 305  *
 306  * The sequence we use to read is:
 307  * 1) read high
 308  * 2) read low
 309  * 3) read high again, if it rolled re-read both low and high again.
 310  *
 311  * Writing STICK safely is also tricky:
 312  * 1) write low to zero
 313  * 2) write high
 314  * 3) write low
 315  */
 316 static unsigned long __hbird_read_stick(void)
 317 {
 318         unsigned long ret, tmp1, tmp2, tmp3;
 319         unsigned long addr = HBIRD_STICK_ADDR+8;
 320
 321         __asm__ __volatile__("ldxa      [%1] %5, %2\n"
 322                              "1:\n\t"
 323                              "sub       %1, 0x8, %1\n\t"
 324                              "ldxa      [%1] %5, %3\n\t"
 325                              "add       %1, 0x8, %1\n\t"
 326                              "ldxa      [%1] %5, %4\n\t"
 327                              "cmp       %4, %2\n\t"
 328                              "bne,a,pn  %%xcc, 1b\n\t"
 329                              " mov      %4, %2\n\t"
 330                              "sllx      %4, 32, %4\n\t"
 331                              "or        %3, %4, %0\n\t"
 332                              : "=&r" (ret), "=&r" (addr),
 333                                "=&r" (tmp1), "=&r" (tmp2), "=&r" (tmp3)
 334                              : "i" (ASI_PHYS_BYPASS_EC_E), "1" (addr));
 335
 336         return ret;
 337 }
 338
 339 static void __hbird_write_stick(unsigned long val)
 340 {
 341         unsigned long low = (val & 0xffffffffUL);
 342         unsigned long high = (val >> 32UL);
 343         unsigned long addr = HBIRD_STICK_ADDR;
 344
 345         __asm__ __volatile__("stxa      %%g0, [%0] %4\n\t"
 346                              "add       %0, 0x8, %0\n\t"
 347                              "stxa      %3, [%0] %4\n\t"
 348                              "sub       %0, 0x8, %0\n\t"
 349                              "stxa      %2, [%0] %4"
 350                              : "=&r" (addr)
 351                              : "0" (addr), "r" (low), "r" (high),
 352                                "i" (ASI_PHYS_BYPASS_EC_E));
 353 }
 354
 355 static void __hbird_write_compare(unsigned long val)
 356 {
 357         unsigned long low = (val & 0xffffffffUL);
 358         unsigned long high = (val >> 32UL);
 359         unsigned long addr = HBIRD_STICKCMP_ADDR + 0x8UL;
 360
 361         __asm__ __volatile__("stxa      %3, [%0] %4\n\t"
 362                              "sub       %0, 0x8, %0\n\t"
 363                              "stxa      %2, [%0] %4"
 364                              : "=&r" (addr)
 365                              : "0" (addr), "r" (low), "r" (high),
 366                                "i" (ASI_PHYS_BYPASS_EC_E));
 367 }
 368
 369 static void hbtick_disable_irq(void)
 370 {
 371         __hbird_write_compare(TICKCMP_IRQ_BIT);
 372 }
 373
 374 static void hbtick_init_tick(void)
 375 {
 376         tick_disable_protection();
 377
 378         /* XXX This seems to be necessary to 'jumpstart' Hummingbird
 379          * XXX into actually sending STICK interrupts.  I think because
 380          * XXX of how we store %tick_cmpr in head.S this somehow resets the
 381          * XXX {TICK + STICK} interrupt mux.  -DaveM
 382          */
 383         __hbird_write_stick(__hbird_read_stick());
 384
 385         hbtick_disable_irq();
 386 }
 387
 388 static unsigned long long hbtick_get_tick(void)
 389 {
 390         return __hbird_read_stick() & ~TICK_PRIV_BIT;
 391 }
 392
 393 static unsigned long hbtick_add_tick(unsigned long adj)
 394 {
 395         unsigned long val;
 396
 397         val = __hbird_read_stick() + adj;
 398         __hbird_write_stick(val);
 399
 400         return val;
 401 }
 402
 403 static int hbtick_add_compare(unsigned long adj)
 404 {
 405         unsigned long val = __hbird_read_stick();
 406         unsigned long val2;
 407
 408         val &= ~TICKCMP_IRQ_BIT;
 409         val += adj;
 410         __hbird_write_compare(val);
 411
 412         val2 = __hbird_read_stick() & ~TICKCMP_IRQ_BIT;
 413
 414         return ((long)(val2 - val)) > 0L;
 415 }
 416
 417 static unsigned long hbtick_get_frequency(void)
 418 {
 419         return prom_getintdefault(prom_root_node, "stick-frequency", 0);
 420 }
 421
 422 static struct sparc64_tick_ops hbtick_operations __read_mostly = {
 423         .name           =       "hbtick",
 424         .init_tick      =       hbtick_init_tick,
 425         .disable_irq    =       hbtick_disable_irq,
 426         .get_tick       =       hbtick_get_tick,
 427         .add_tick       =       hbtick_add_tick,
 428         .add_compare    =       hbtick_add_compare,
 429         .get_frequency  =       hbtick_get_frequency,
 430         .softint_mask   =       1UL << 0,
 431 };
 432
 433 unsigned long cmos_regs;
 434 EXPORT_SYMBOL(cmos_regs);
 435
 436 static struct resource rtc_cmos_resource;
 437
 438 static struct platform_device rtc_cmos_device = {
 439         .name           = "rtc_cmos",
 440         .id             = -1,
 441         .resource       = &rtc_cmos_resource,
 442         .num_resources  = 1,
 443 };
 444
 445 static int rtc_probe(struct platform_device *op)
 446 {
 447         struct resource *r;
 448
 449         printk(KERN_INFO "%pOF: RTC regs at 0x%llx\n",
 450                op->dev.of_node, op->resource[0].start);
 451
 452         /* The CMOS RTC driver only accepts IORESOURCE_IO, so cons
 453          * up a fake resource so that the probe works for all cases.
 454          * When the RTC is behind an ISA bus it will have IORESOURCE_IO
 455          * already, whereas when it's behind EBUS is will be IORESOURCE_MEM.
 456          */
 457
 458         r = &rtc_cmos_resource;
 459         r->flags = IORESOURCE_IO;
 460         r->name = op->resource[0].name;
 461         r->start = op->resource[0].start;
 462         r->end = op->resource[0].end;
 463
 464         cmos_regs = op->resource[0].start;
 465         return platform_device_register(&rtc_cmos_device);
 466 }
 467
 468 static const struct of_device_id rtc_match[] = {
 469         {
 470                 .name = "rtc",
 471                 .compatible = "m5819",
 472         },
 473         {
 474                 .name = "rtc",
 475                 .compatible = "isa-m5819p",
 476         },
 477         {
 478                 .name = "rtc",
 479                 .compatible = "isa-m5823p",
 480         },
 481         {
 482                 .name = "rtc",
 483                 .compatible = "ds1287",
 484         },
 485         {},
 486 };
 487
 488 static struct platform_driver rtc_driver = {
 489         .probe          = rtc_probe,
 490         .driver = {
 491                 .name = "rtc",
 492                 .of_match_table = rtc_match,
 493         },
 494 };
 495
 496 static struct platform_device rtc_bq4802_device = {
 497         .name           = "rtc-bq4802",
 498         .id             = -1,
 499         .num_resources  = 1,
 500 };
 501
 502 static int bq4802_probe(struct platform_device *op)
 503 {
 504
 505         printk(KERN_INFO "%pOF: BQ4802 regs at 0x%llx\n",
 506                op->dev.of_node, op->resource[0].start);
 507
 508         rtc_bq4802_device.resource = &op->resource[0];
 509         return platform_device_register(&rtc_bq4802_device);
 510 }
 511
 512 static const struct of_device_id bq4802_match[] = {
 513         {
 514                 .name = "rtc",
 515                 .compatible = "bq4802",
 516         },
 517         {},
 518 };
 519
 520 static struct platform_driver bq4802_driver = {
 521         .probe          = bq4802_probe,
 522         .driver = {
 523                 .name = "bq4802",
 524                 .of_match_table = bq4802_match,
 525         },
 526 };
 527
 528 static unsigned char mostek_read_byte(struct device *dev, u32 ofs)
 529 {
 530         struct platform_device *pdev = to_platform_device(dev);
 531         void __iomem *regs = (void __iomem *) pdev->resource[0].start;
 532
 533         return readb(regs + ofs);
 534 }
 535
 536 static void mostek_write_byte(struct device *dev, u32 ofs, u8 val)
 537 {
 538         struct platform_device *pdev = to_platform_device(dev);
 539         void __iomem *regs = (void __iomem *) pdev->resource[0].start;
 540
 541         writeb(val, regs + ofs);
 542 }
 543
 544 static struct m48t59_plat_data m48t59_data = {
 545         .read_byte      = mostek_read_byte,
 546         .write_byte     = mostek_write_byte,
 547 };
 548
 549 static struct platform_device m48t59_rtc = {
 550         .name           = "rtc-m48t59",
 551         .id             = 0,
 552         .num_resources  = 1,
 553         .dev    = {
 554                 .platform_data = &m48t59_data,
 555         },
 556 };
 557
 558 static int mostek_probe(struct platform_device *op)
 559 {
 560         struct device_node *dp = op->dev.of_node;
 561
 562         /* On an Enterprise system there can be multiple mostek clocks.
 563          * We should only match the one that is on the central FHC bus.
 564          */
 565         if (of_node_name_eq(dp->parent, "fhc") &&
 566             !of_node_name_eq(dp->parent->parent, "central"))
 567                 return -ENODEV;
 568
 569         printk(KERN_INFO "%pOF: Mostek regs at 0x%llx\n",
 570                dp, op->resource[0].start);
 571
 572         m48t59_rtc.resource = &op->resource[0];
 573         return platform_device_register(&m48t59_rtc);
 574 }
 575
 576 static const struct of_device_id mostek_match[] = {
 577         {
 578                 .name = "eeprom",
 579         },
 580         {},
 581 };
 582
 583 static struct platform_driver mostek_driver = {
 584         .probe          = mostek_probe,
 585         .driver = {
 586                 .name = "mostek",
 587                 .of_match_table = mostek_match,
 588         },
 589 };
 590
 591 static struct platform_device rtc_sun4v_device = {
 592         .name           = "rtc-sun4v",
 593         .id             = -1,
 594 };
 595
 596 static struct platform_device rtc_starfire_device = {
 597         .name           = "rtc-starfire",
 598         .id             = -1,
 599 };
 600
 601 static int __init clock_init(void)
 602 {
 603         if (this_is_starfire)
 604                 return platform_device_register(&rtc_starfire_device);
 605
 606         if (tlb_type == hypervisor)
 607                 return platform_device_register(&rtc_sun4v_device);
 608
 609         (void) platform_driver_register(&rtc_driver);
 610         (void) platform_driver_register(&mostek_driver);
 611         (void) platform_driver_register(&bq4802_driver);
 612
 613         return 0;
 614 }
 615
 616 /* Must be after subsys_initcall() so that busses are probed.  Must
 617  * be before device_initcall() because things like the RTC driver
 618  * need to see the clock registers.
 619  */
 620 fs_initcall(clock_init);
 621
 622 /* Return true if this is Hummingbird, aka Ultra-IIe */
 623 static bool is_hummingbird(void)
 624 {
 625         unsigned long ver, manuf, impl;
 626
 627         __asm__ __volatile__ ("rdpr %%ver, %0"
 628                               : "=&r" (ver));
 629         manuf = ((ver >> 48) & 0xffff);
 630         impl = ((ver >> 32) & 0xffff);
 631
 632         return (manuf == 0x17 && impl == 0x13);
 633 }
 634
 635 struct freq_table {
 636         unsigned long clock_tick_ref;
 637         unsigned int ref_freq;
 638 };
 639 static DEFINE_PER_CPU(struct freq_table, sparc64_freq_table) = { 0, 0 };
 640
 641 unsigned long sparc64_get_clock_tick(unsigned int cpu)
 642 {
 643         struct freq_table *ft = &per_cpu(sparc64_freq_table, cpu);
 644
 645         if (ft->clock_tick_ref)
 646                 return ft->clock_tick_ref;
 647         return cpu_data(cpu).clock_tick;
 648 }
 649 EXPORT_SYMBOL(sparc64_get_clock_tick);
 650
 651 #ifdef CONFIG_CPU_FREQ
 652
 653 static int sparc64_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
 654                                     void *data)
 655 {
 656         struct cpufreq_freqs *freq = data;
 657         unsigned int cpu;
 658         struct freq_table *ft;
 659
 660         for_each_cpu(cpu, freq->policy->cpus) {
 661                 ft = &per_cpu(sparc64_freq_table, cpu);
 662
 663                 if (!ft->ref_freq) {
 664                         ft->ref_freq = freq->old;
 665                         ft->clock_tick_ref = cpu_data(cpu).clock_tick;
 666                 }
 667
 668                 if ((val == CPUFREQ_PRECHANGE  && freq->old < freq->new) ||
 669                     (val == CPUFREQ_POSTCHANGE && freq->old > freq->new)) {
 670                         cpu_data(cpu).clock_tick =
 671                                 cpufreq_scale(ft->clock_tick_ref, ft->ref_freq,
 672                                               freq->new);
 673                 }
 674         }
 675
 676         return 0;
 677 }
 678
 679 static struct notifier_block sparc64_cpufreq_notifier_block = {
 680         .notifier_call  = sparc64_cpufreq_notifier
 681 };
 682
 683 static int __init register_sparc64_cpufreq_notifier(void)
 684 {
 685
 686         cpufreq_register_notifier(&sparc64_cpufreq_notifier_block,
 687                                   CPUFREQ_TRANSITION_NOTIFIER);
 688         return 0;
 689 }
 690
 691 core_initcall(register_sparc64_cpufreq_notifier);
 692
 693 #endif /* CONFIG_CPU_FREQ */
 694
 695 static int sparc64_next_event(unsigned long delta,
 696                               struct clock_event_device *evt)
 697 {
 698         return tick_operations.add_compare(delta) ? -ETIME : 0;
 699 }
 700
 701 static int sparc64_timer_shutdown(struct clock_event_device *evt)
 702 {
 703         tick_operations.disable_irq();
 704         return 0;
 705 }
 706
 707 static struct clock_event_device sparc64_clockevent = {
 708         .features               = CLOCK_EVT_FEAT_ONESHOT,
 709         .set_state_shutdown     = sparc64_timer_shutdown,
 710         .set_next_event         = sparc64_next_event,
 711         .rating                 = 100,
 712         .shift                  = 30,
 713         .irq                    = -1,
 714 };
 715 static DEFINE_PER_CPU(struct clock_event_device, sparc64_events);
 716
 717 void __irq_entry timer_interrupt(int irq, struct pt_regs *regs)
 718 {
 719         struct pt_regs *old_regs = set_irq_regs(regs);
 720         unsigned long tick_mask = tick_operations.softint_mask;
 721         int cpu = smp_processor_id();
 722         struct clock_event_device *evt = &per_cpu(sparc64_events, cpu);
 723
 724         clear_softint(tick_mask);
 725
 726         irq_enter();
 727
 728         local_cpu_data().irq0_irqs++;
 729         kstat_incr_irq_this_cpu(0);
 730
 731         if (unlikely(!evt->event_handler)) {
 732                 printk(KERN_WARNING
 733                        "Spurious SPARC64 timer interrupt on cpu %d\n", cpu);
 734         } else
 735                 evt->event_handler(evt);
 736
 737         irq_exit();
 738
 739         set_irq_regs(old_regs);
 740 }
 741
 742 void setup_sparc64_timer(void)
 743 {
 744         struct clock_event_device *sevt;
 745         unsigned long pstate;
 746
 747         /* Guarantee that the following sequences execute
 748          * uninterrupted.
 749          */
 750         __asm__ __volatile__("rdpr      %%pstate, %0\n\t"
 751                              "wrpr      %0, %1, %%pstate"
 752                              : "=r" (pstate)
 753                              : "i" (PSTATE_IE));
 754
 755         tick_operations.init_tick();
 756
 757         /* Restore PSTATE_IE. */
 758         __asm__ __volatile__("wrpr      %0, 0x0, %%pstate"
 759                              : /* no outputs */
 760                              : "r" (pstate));
 761
 762         sevt = this_cpu_ptr(&sparc64_events);
 763
 764         memcpy(sevt, &sparc64_clockevent, sizeof(*sevt));
 765         sevt->cpumask = cpumask_of(smp_processor_id());
 766
 767         clockevents_register_device(sevt);
 768 }
 769
 770 #define SPARC64_NSEC_PER_CYC_SHIFT      10UL
 771
 772 static struct clocksource clocksource_tick = {
 773         .rating         = 100,
 774         .mask           = CLOCKSOURCE_MASK(64),
 775         .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
 776 };
 777
 778 static unsigned long tb_ticks_per_usec __read_mostly;
 779
 780 void __delay(unsigned long loops)
 781 {
 782         unsigned long bclock = get_tick();
 783
 784         while ((get_tick() - bclock) < loops)
 785                 ;
 786 }
 787 EXPORT_SYMBOL(__delay);
 788
 789 void udelay(unsigned long usecs)
 790 {
 791         __delay(tb_ticks_per_usec * usecs);
 792 }
 793 EXPORT_SYMBOL(udelay);
 794
 795 static u64 clocksource_tick_read(struct clocksource *cs)
 796 {
 797         return get_tick();
 798 }
 799
 800 static void __init get_tick_patch(void)
 801 {
 802         unsigned int *addr, *instr, i;
 803         struct get_tick_patch *p;
 804
 805         if (tlb_type == spitfire && is_hummingbird())
 806                 return;
 807
 808         for (p = &__get_tick_patch; p < &__get_tick_patch_end; p++) {
 809                 instr = (tlb_type == spitfire) ? p->tick : p->stick;
 810                 addr = (unsigned int *)(unsigned long)p->addr;
 811                 for (i = 0; i < GET_TICK_NINSTR; i++) {
 812                         addr[i] = instr[i];
 813                         /* ensure that address is modified before flush */
 814                         wmb();
 815                         flushi(&addr[i]);
 816                 }
 817         }
 818 }
 819
 820 static void __init init_tick_ops(struct sparc64_tick_ops *ops)
 821 {
 822         unsigned long freq, quotient, tick;
 823
 824         freq = ops->get_frequency();
 825         quotient = clocksource_hz2mult(freq, SPARC64_NSEC_PER_CYC_SHIFT);
 826         tick = ops->get_tick();
 827
 828         ops->offset = (tick * quotient) >> SPARC64_NSEC_PER_CYC_SHIFT;
 829         ops->ticks_per_nsec_quotient = quotient;
 830         ops->frequency = freq;
 831         tick_operations = *ops;
 832         get_tick_patch();
 833 }
 834
 835 void __init time_init_early(void)
 836 {
 837         if (tlb_type == spitfire) {
 838                 if (is_hummingbird()) {
 839                         init_tick_ops(&hbtick_operations);
 840                         clocksource_tick.archdata.vclock_mode = VCLOCK_NONE;
 841                 } else {
 842                         init_tick_ops(&tick_operations);
 843                         clocksource_tick.archdata.vclock_mode = VCLOCK_TICK;
 844                 }
 845         } else {
 846                 init_tick_ops(&stick_operations);
 847                 clocksource_tick.archdata.vclock_mode = VCLOCK_STICK;
 848         }
 849 }
 850
 851 void __init time_init(void)
 852 {
 853         unsigned long freq;
 854
 855         freq = tick_operations.frequency;
 856         tb_ticks_per_usec = freq / USEC_PER_SEC;
 857
 858         clocksource_tick.name = tick_operations.name;
 859         clocksource_tick.read = clocksource_tick_read;
 860
 861         clocksource_register_hz(&clocksource_tick, freq);
 862         printk("clocksource: mult[%x] shift[%d]\n",
 863                clocksource_tick.mult, clocksource_tick.shift);
 864
 865         sparc64_clockevent.name = tick_operations.name;
 866         clockevents_calc_mult_shift(&sparc64_clockevent, freq, 4);
 867
 868         sparc64_clockevent.max_delta_ns =
 869                 clockevent_delta2ns(0x7fffffffffffffffUL, &sparc64_clockevent);
 870         sparc64_clockevent.max_delta_ticks = 0x7fffffffffffffffUL;
 871         sparc64_clockevent.min_delta_ns =
 872                 clockevent_delta2ns(0xF, &sparc64_clockevent);
 873         sparc64_clockevent.min_delta_ticks = 0xF;
 874
 875         printk("clockevent: mult[%x] shift[%d]\n",
 876                sparc64_clockevent.mult, sparc64_clockevent.shift);
 877
 878         setup_sparc64_timer();
 879 }
 880
 881 unsigned long long sched_clock(void)
 882 {
 883         unsigned long quotient = tick_operations.ticks_per_nsec_quotient;
 884         unsigned long offset = tick_operations.offset;
 885
 886         /* Use barrier so the compiler emits the loads first and overlaps load
 887          * latency with reading tick, because reading %tick/%stick is a
 888          * post-sync instruction that will flush and restart subsequent
 889          * instructions after it commits.
 890          */
 891         barrier();
 892
 893         return ((get_tick() * quotient) >> SPARC64_NSEC_PER_CYC_SHIFT) - offset;
 894 }
 895
 896 int read_current_timer(unsigned long *timer_val)
 897 {
 898         *timer_val = get_tick();
 899         return 0;
 900 }