time.c 3.0 KB

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  1. // SPDX-License-Identifier: GPL-2.0
  2. /*
  3. * Copyright (c) 1991,1992,1995 Linus Torvalds
  4. * Copyright (c) 1994 Alan Modra
  5. * Copyright (c) 1995 Markus Kuhn
  6. * Copyright (c) 1996 Ingo Molnar
  7. * Copyright (c) 1998 Andrea Arcangeli
  8. * Copyright (c) 2002,2006 Vojtech Pavlik
  9. * Copyright (c) 2003 Andi Kleen
  10. *
  11. */
  12. #include <linux/clocksource.h>
  13. #include <linux/clockchips.h>
  14. #include <linux/interrupt.h>
  15. #include <linux/irq.h>
  16. #include <linux/i8253.h>
  17. #include <linux/time.h>
  18. #include <linux/export.h>
  19. #include <asm/vsyscall.h>
  20. #include <asm/x86_init.h>
  21. #include <asm/i8259.h>
  22. #include <asm/timer.h>
  23. #include <asm/hpet.h>
  24. #include <asm/time.h>
  25. unsigned long profile_pc(struct pt_regs *regs)
  26. {
  27. unsigned long pc = instruction_pointer(regs);
  28. if (!user_mode(regs) && in_lock_functions(pc)) {
  29. #ifdef CONFIG_FRAME_POINTER
  30. return *(unsigned long *)(regs->bp + sizeof(long));
  31. #else
  32. unsigned long *sp = (unsigned long *)regs->sp;
  33. /*
  34. * Return address is either directly at stack pointer
  35. * or above a saved flags. Eflags has bits 22-31 zero,
  36. * kernel addresses don't.
  37. */
  38. if (sp[0] >> 22)
  39. return sp[0];
  40. if (sp[1] >> 22)
  41. return sp[1];
  42. #endif
  43. }
  44. return pc;
  45. }
  46. EXPORT_SYMBOL(profile_pc);
  47. /*
  48. * Default timer interrupt handler for PIT/HPET
  49. */
  50. static irqreturn_t timer_interrupt(int irq, void *dev_id)
  51. {
  52. global_clock_event->event_handler(global_clock_event);
  53. return IRQ_HANDLED;
  54. }
  55. static void __init setup_default_timer_irq(void)
  56. {
  57. unsigned long flags = IRQF_NOBALANCING | IRQF_IRQPOLL | IRQF_TIMER;
  58. /*
  59. * Unconditionally register the legacy timer interrupt; even
  60. * without legacy PIC/PIT we need this for the HPET0 in legacy
  61. * replacement mode.
  62. */
  63. if (request_irq(0, timer_interrupt, flags, "timer", NULL))
  64. pr_info("Failed to register legacy timer interrupt\n");
  65. }
  66. /* Default timer init function */
  67. void __init hpet_time_init(void)
  68. {
  69. if (!hpet_enable()) {
  70. if (!pit_timer_init())
  71. return;
  72. }
  73. setup_default_timer_irq();
  74. }
  75. static __init void x86_late_time_init(void)
  76. {
  77. /*
  78. * Before PIT/HPET init, select the interrupt mode. This is required
  79. * to make the decision whether PIT should be initialized correct.
  80. */
  81. x86_init.irqs.intr_mode_select();
  82. /* Setup the legacy timers */
  83. x86_init.timers.timer_init();
  84. /*
  85. * After PIT/HPET timers init, set up the final interrupt mode for
  86. * delivering IRQs.
  87. */
  88. x86_init.irqs.intr_mode_init();
  89. tsc_init();
  90. if (static_cpu_has(X86_FEATURE_WAITPKG))
  91. use_tpause_delay();
  92. }
  93. /*
  94. * Initialize TSC and delay the periodic timer init to
  95. * late x86_late_time_init() so ioremap works.
  96. */
  97. void __init time_init(void)
  98. {
  99. late_time_init = x86_late_time_init;
  100. }
  101. /*
  102. * Sanity check the vdso related archdata content.
  103. */
  104. void clocksource_arch_init(struct clocksource *cs)
  105. {
  106. if (cs->vdso_clock_mode == VDSO_CLOCKMODE_NONE)
  107. return;
  108. if (cs->mask != CLOCKSOURCE_MASK(64)) {
  109. pr_warn("clocksource %s registered with invalid mask %016llx for VDSO. Disabling VDSO support.\n",
  110. cs->name, cs->mask);
  111. cs->vdso_clock_mode = VDSO_CLOCKMODE_NONE;
  112. }
  113. }