cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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time.c (3044B)

      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
     13#include <linux/clocksource.h>
     14#include <linux/clockchips.h>
     15#include <linux/interrupt.h>
     16#include <linux/irq.h>
     17#include <linux/i8253.h>
     18#include <linux/time.h>
     19#include <linux/export.h>
     20
     21#include <asm/vsyscall.h>
     22#include <asm/x86_init.h>
     23#include <asm/i8259.h>
     24#include <asm/timer.h>
     25#include <asm/hpet.h>
     26#include <asm/time.h>
     27
     28unsigned long profile_pc(struct pt_regs *regs)
     29{
     30	unsigned long pc = instruction_pointer(regs);
     31
     32	if (!user_mode(regs) && in_lock_functions(pc)) {
     33#ifdef CONFIG_FRAME_POINTER
     34		return *(unsigned long *)(regs->bp + sizeof(long));
     35#else
     36		unsigned long *sp = (unsigned long *)regs->sp;
     37		/*
     38		 * Return address is either directly at stack pointer
     39		 * or above a saved flags. Eflags has bits 22-31 zero,
     40		 * kernel addresses don't.
     41		 */
     42		if (sp[0] >> 22)
     43			return sp[0];
     44		if (sp[1] >> 22)
     45			return sp[1];
     46#endif
     47	}
     48	return pc;
     49}
     50EXPORT_SYMBOL(profile_pc);
     51
     52/*
     53 * Default timer interrupt handler for PIT/HPET
     54 */
     55static irqreturn_t timer_interrupt(int irq, void *dev_id)
     56{
     57	global_clock_event->event_handler(global_clock_event);
     58	return IRQ_HANDLED;
     59}
     60
     61static void __init setup_default_timer_irq(void)
     62{
     63	unsigned long flags = IRQF_NOBALANCING | IRQF_IRQPOLL | IRQF_TIMER;
     64
     65	/*
     66	 * Unconditionally register the legacy timer interrupt; even
     67	 * without legacy PIC/PIT we need this for the HPET0 in legacy
     68	 * replacement mode.
     69	 */
     70	if (request_irq(0, timer_interrupt, flags, "timer", NULL))
     71		pr_info("Failed to register legacy timer interrupt\n");
     72}
     73
     74/* Default timer init function */
     75void __init hpet_time_init(void)
     76{
     77	if (!hpet_enable()) {
     78		if (!pit_timer_init())
     79			return;
     80	}
     81
     82	setup_default_timer_irq();
     83}
     84
     85static __init void x86_late_time_init(void)
     86{
     87	/*
     88	 * Before PIT/HPET init, select the interrupt mode. This is required
     89	 * to make the decision whether PIT should be initialized correct.
     90	 */
     91	x86_init.irqs.intr_mode_select();
     92
     93	/* Setup the legacy timers */
     94	x86_init.timers.timer_init();
     95
     96	/*
     97	 * After PIT/HPET timers init, set up the final interrupt mode for
     98	 * delivering IRQs.
     99	 */
    100	x86_init.irqs.intr_mode_init();
    101	tsc_init();
    102
    103	if (static_cpu_has(X86_FEATURE_WAITPKG))
    104		use_tpause_delay();
    105}
    106
    107/*
    108 * Initialize TSC and delay the periodic timer init to
    109 * late x86_late_time_init() so ioremap works.
    110 */
    111void __init time_init(void)
    112{
    113	late_time_init = x86_late_time_init;
    114}
    115
    116/*
    117 * Sanity check the vdso related archdata content.
    118 */
    119void clocksource_arch_init(struct clocksource *cs)
    120{
    121	if (cs->vdso_clock_mode == VDSO_CLOCKMODE_NONE)
    122		return;
    123
    124	if (cs->mask != CLOCKSOURCE_MASK(64)) {
    125		pr_warn("clocksource %s registered with invalid mask %016llx for VDSO. Disabling VDSO support.\n",
    126			cs->name, cs->mask);
    127		cs->vdso_clock_mode = VDSO_CLOCKMODE_NONE;
    128	}
    129}