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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ip27-timer.c (4157B)

      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * Copyright (C) 1999, 2000, 05, 06 Ralf Baechle (ralf@linux-mips.org)
      4 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
      5 */
      6#include <linux/bcd.h>
      7#include <linux/clockchips.h>
      8#include <linux/init.h>
      9#include <linux/kernel.h>
     10#include <linux/sched.h>
     11#include <linux/sched_clock.h>
     12#include <linux/interrupt.h>
     13#include <linux/kernel_stat.h>
     14#include <linux/param.h>
     15#include <linux/smp.h>
     16#include <linux/time.h>
     17#include <linux/timex.h>
     18#include <linux/mm.h>
     19#include <linux/platform_device.h>
     20
     21#include <asm/time.h>
     22#include <asm/sgialib.h>
     23#include <asm/sn/klconfig.h>
     24#include <asm/sn/arch.h>
     25#include <asm/sn/addrs.h>
     26#include <asm/sn/agent.h>
     27
     28#include "ip27-common.h"
     29
     30static int rt_next_event(unsigned long delta, struct clock_event_device *evt)
     31{
     32	unsigned int cpu = smp_processor_id();
     33	int slice = cputoslice(cpu);
     34	unsigned long cnt;
     35
     36	cnt = LOCAL_HUB_L(PI_RT_COUNT);
     37	cnt += delta;
     38	LOCAL_HUB_S(PI_RT_COMPARE_A + PI_COUNT_OFFSET * slice, cnt);
     39
     40	return LOCAL_HUB_L(PI_RT_COUNT) >= cnt ? -ETIME : 0;
     41}
     42
     43static DEFINE_PER_CPU(struct clock_event_device, hub_rt_clockevent);
     44static DEFINE_PER_CPU(char [11], hub_rt_name);
     45
     46static irqreturn_t hub_rt_counter_handler(int irq, void *dev_id)
     47{
     48	unsigned int cpu = smp_processor_id();
     49	struct clock_event_device *cd = &per_cpu(hub_rt_clockevent, cpu);
     50	int slice = cputoslice(cpu);
     51
     52	/*
     53	 * Ack
     54	 */
     55	LOCAL_HUB_S(PI_RT_PEND_A + PI_COUNT_OFFSET * slice, 0);
     56	cd->event_handler(cd);
     57
     58	return IRQ_HANDLED;
     59}
     60
     61struct irqaction hub_rt_irqaction = {
     62	.handler	= hub_rt_counter_handler,
     63	.percpu_dev_id	= &hub_rt_clockevent,
     64	.flags		= IRQF_PERCPU | IRQF_TIMER,
     65	.name		= "hub-rt",
     66};
     67
     68/*
     69 * This is a hack; we really need to figure these values out dynamically
     70 *
     71 * Since 800 ns works very well with various HUB frequencies, such as
     72 * 360, 380, 390 and 400 MHZ, we use 800 ns rtc cycle time.
     73 *
     74 * Ralf: which clock rate is used to feed the counter?
     75 */
     76#define NSEC_PER_CYCLE		800
     77#define CYCLES_PER_SEC		(NSEC_PER_SEC / NSEC_PER_CYCLE)
     78
     79void hub_rt_clock_event_init(void)
     80{
     81	unsigned int cpu = smp_processor_id();
     82	struct clock_event_device *cd = &per_cpu(hub_rt_clockevent, cpu);
     83	unsigned char *name = per_cpu(hub_rt_name, cpu);
     84
     85	sprintf(name, "hub-rt %d", cpu);
     86	cd->name		= name;
     87	cd->features		= CLOCK_EVT_FEAT_ONESHOT;
     88	clockevent_set_clock(cd, CYCLES_PER_SEC);
     89	cd->max_delta_ns	= clockevent_delta2ns(0xfffffffffffff, cd);
     90	cd->max_delta_ticks	= 0xfffffffffffff;
     91	cd->min_delta_ns	= clockevent_delta2ns(0x300, cd);
     92	cd->min_delta_ticks	= 0x300;
     93	cd->rating		= 200;
     94	cd->irq			= IP27_RT_TIMER_IRQ;
     95	cd->cpumask		= cpumask_of(cpu);
     96	cd->set_next_event	= rt_next_event;
     97	clockevents_register_device(cd);
     98
     99	enable_percpu_irq(IP27_RT_TIMER_IRQ, IRQ_TYPE_NONE);
    100}
    101
    102static void __init hub_rt_clock_event_global_init(void)
    103{
    104	irq_set_handler(IP27_RT_TIMER_IRQ, handle_percpu_devid_irq);
    105	irq_set_percpu_devid(IP27_RT_TIMER_IRQ);
    106	setup_percpu_irq(IP27_RT_TIMER_IRQ, &hub_rt_irqaction);
    107}
    108
    109static u64 hub_rt_read(struct clocksource *cs)
    110{
    111	return REMOTE_HUB_L(cputonasid(0), PI_RT_COUNT);
    112}
    113
    114struct clocksource hub_rt_clocksource = {
    115	.name	= "HUB-RT",
    116	.rating = 200,
    117	.read	= hub_rt_read,
    118	.mask	= CLOCKSOURCE_MASK(52),
    119	.flags	= CLOCK_SOURCE_IS_CONTINUOUS,
    120};
    121
    122static u64 notrace hub_rt_read_sched_clock(void)
    123{
    124	return REMOTE_HUB_L(cputonasid(0), PI_RT_COUNT);
    125}
    126
    127static void __init hub_rt_clocksource_init(void)
    128{
    129	struct clocksource *cs = &hub_rt_clocksource;
    130
    131	clocksource_register_hz(cs, CYCLES_PER_SEC);
    132
    133	sched_clock_register(hub_rt_read_sched_clock, 52, CYCLES_PER_SEC);
    134}
    135
    136void __init plat_time_init(void)
    137{
    138	hub_rt_clocksource_init();
    139	hub_rt_clock_event_global_init();
    140	hub_rt_clock_event_init();
    141}
    142
    143void hub_rtc_init(nasid_t nasid)
    144{
    145
    146	/*
    147	 * We only need to initialize the current node.
    148	 * If this is not the current node then it is a cpuless
    149	 * node and timeouts will not happen there.
    150	 */
    151	if (get_nasid() == nasid) {
    152		LOCAL_HUB_S(PI_RT_EN_A, 1);
    153		LOCAL_HUB_S(PI_RT_EN_B, 1);
    154		LOCAL_HUB_S(PI_PROF_EN_A, 0);
    155		LOCAL_HUB_S(PI_PROF_EN_B, 0);
    156		LOCAL_HUB_S(PI_RT_COUNT, 0);
    157		LOCAL_HUB_S(PI_RT_PEND_A, 0);
    158		LOCAL_HUB_S(PI_RT_PEND_B, 0);
    159	}
    160}