linux/arch/x86/platform/uv/uv_time.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * SGI RTC clock/timer routines.
 *
 *  (C) Copyright 2020 Hewlett Packard Enterprise Development LP
 *  Copyright (c) 2009-2013 Silicon Graphics, Inc.  All Rights Reserved.
 *  Copyright (c) Dimitri Sivanich
 */
#include <linux/clockchips.h>
#include <linux/slab.h>

#include <asm/uv/uv_mmrs.h>
#include <asm/uv/uv_hub.h>
#include <asm/uv/bios.h>
#include <asm/uv/uv.h>
#include <asm/apic.h>
#include <asm/cpu.h>

#define RTC_NAME …

static u64 uv_read_rtc(struct clocksource *cs);
static int uv_rtc_next_event(unsigned long, struct clock_event_device *);
static int uv_rtc_shutdown(struct clock_event_device *evt);

static struct clocksource clocksource_uv = …;

static struct clock_event_device clock_event_device_uv = …;

static DEFINE_PER_CPU(struct clock_event_device, cpu_ced);

/* There is one of these allocated per node */
struct uv_rtc_timer_head { … };

/*
 * Access to uv_rtc_timer_head via blade id.
 */
static struct uv_rtc_timer_head		**blade_info __read_mostly;

static int				uv_rtc_evt_enable;

/*
 * Hardware interface routines
 */

/* Send IPIs to another node */
static void uv_rtc_send_IPI(int cpu)
{ … }

/* Check for an RTC interrupt pending */
static int uv_intr_pending(int pnode)
{ … }

/* Setup interrupt and return non-zero if early expiration occurred. */
static int uv_setup_intr(int cpu, u64 expires)
{ … }

/*
 * Per-cpu timer tracking routines
 */

static __init void uv_rtc_deallocate_timers(void)
{ … }

/* Allocate per-node list of cpu timer expiration times. */
static __init int uv_rtc_allocate_timers(void)
{ … }

/* Find and set the next expiring timer.  */
static void uv_rtc_find_next_timer(struct uv_rtc_timer_head *head, int pnode)
{ … }

/*
 * Set expiration time for current cpu.
 *
 * Returns 1 if we missed the expiration time.
 */
static int uv_rtc_set_timer(int cpu, u64 expires)
{ … }

/*
 * Unset expiration time for current cpu.
 *
 * Returns 1 if this timer was pending.
 */
static int uv_rtc_unset_timer(int cpu, int force)
{ … }


/*
 * Kernel interface routines.
 */

/*
 * Read the RTC.
 *
 * Starting with HUB rev 2.0, the UV RTC register is replicated across all
 * cachelines of its own page.  This allows faster simultaneous reads
 * from a given socket.
 */
static u64 uv_read_rtc(struct clocksource *cs)
{ … }

/*
 * Program the next event, relative to now
 */
static int uv_rtc_next_event(unsigned long delta,
			     struct clock_event_device *ced)
{ … }

/*
 * Shutdown the RTC timer
 */
static int uv_rtc_shutdown(struct clock_event_device *evt)
{ … }

static void uv_rtc_interrupt(void)
{ … }

static int __init uv_enable_evt_rtc(char *str)
{ … }
__setup(…);

static __init void uv_rtc_register_clockevents(struct work_struct *dummy)
{ … }

static __init int uv_rtc_setup_clock(void)
{ … }
arch_initcall(uv_rtc_setup_clock);