/*
* linux/kernel/timer.c
*
* Kernel internal timers, kernel timekeeping, basic process system calls
*
* Copyright (C) 1991, 1992 Linus Torvalds
*
* 1997-01-28 Modified by Finn Arne Gangstad to make timers scale better.
*
* 1997-09-10 Updated NTP code according to technical memorandum Jan '96
* "A Kernel Model for Precision Timekeeping" by Dave Mills
* 1998-12-24 Fixed a xtime SMP race (we need the xtime_lock rw spinlock to
* serialize accesses to xtime/lost_ticks).
* Copyright (C) 1998 Andrea Arcangeli
* 1999-03-10 Improved NTP compatibility by Ulrich Windl
* 2002-05-31 Move sys_sysinfo here and make its locking sane, Robert Love
* 2000-10-05 Implemented scalable SMP per-CPU timer handling.
* Copyright (C) 2000, 2001, 2002 Ingo Molnar
* Designed by David S. Miller, Alexey Kuznetsov and Ingo Molnar
*/
#include <linux/kernel_stat.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/percpu.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/notifier.h>
#include <linux/thread_info.h>
#include <linux/time.h>
#include <linux/jiffies.h>
#include <linux/posix-timers.h>
#include <linux/cpu.h>
#include <linux/syscalls.h>
#include <asm/uaccess.h>
#include <asm/unistd.h>
#include <asm/div64.h>
#include <asm/timex.h>
#include <asm/io.h>
#ifdef CONFIG_TIME_INTERPOLATION
static void time_interpolator_update(long delta_nsec);
#else
#define time_interpolator_update(x)
#endif
/*
* per-CPU timer vector definitions:
*/
#define TVN_BITS (CONFIG_BASE_SMALL ? 4 : 6)
#define TVR_BITS (CONFIG_BASE_SMALL ? 6 : 8)
#define TVN_SIZE (1 << TVN_BITS)
#define TVR_SIZE (1 << TVR_BITS)
#define TVN_MASK (TVN_SIZE - 1)
#define TVR_MASK (TVR_SIZE - 1)
struct timer_base_s {
spinlock_t lock;
struct timer_list *running_timer;
};
typedef struct tvec_s {
struct list_head vec[TVN_SIZE];
} tvec_t;
typedef struct tvec_root_s {
struct list_head vec[TVR_SIZE];
} tvec_root_t;
struct tvec_t_base_s {
struct timer_base_s t_base;
unsigned long timer_jiffies;
tvec_root_t tv1;
tvec_t tv2;
tvec_t tv3;
tvec_t tv4;
tvec_t tv5;
} ____cacheline_aligned_in_smp;
typedef struct tvec_t_base_s tvec_base_t;
static DEFINE_PER_CPU(tvec_base_t, tvec_bases);
static inline void set_running_timer(tvec_base_t *base,
struct timer_list *timer)
{
#ifdef CONFIG_SMP
base->t_base.running_timer = timer;
#endif
}
static void check_timer_failed(struct timer_list *timer)
{
static int whine_count;
if (whine_count < 16) {
whine_count++;
printk("Uninitialised timer!\n");
printk("This is just a warning. Your computer is OK\n");
printk("function=0x%p, data=0x%lx\n",
timer->function, timer->data);
dump_stack();
}
/*
* Now fix it up
*/
timer->magic = TIMER_MAGIC;
}
static inline void check_timer(struct timer_list *timer)
{
if (timer->magic != TIMER_MAGIC)
check_timer_failed(timer);
}
static void internal_add_timer(tvec_base_t *base, struct timer_list *timer)
{
unsigned long expires = timer->expires;
unsigned long idx = expires - base->timer_jiffies;
struct list_head *vec;
if (idx < TVR_SIZE) {
int i = expires & TVR_MASK;
vec = base->tv1.vec + i;
} else if (idx < 1 << (TVR_BITS + TVN_BITS)) {
int i = (expires >> TVR_BITS) & TVN_MASK;
vec = base->tv2.vec + i;
} else if (idx < 1 << (TVR_BITS + 2 * TVN_BITS)) {
int i = (expires >> (TVR_BITS + TVN_BITS)) & TVN_MASK;
vec = base->tv3.vec + i;
} else if (idx < 1 << (TVR_BITS + 3 * TVN_BITS)) {
int i = (expires >> (TVR_BITS + 2 * TVN_BITS)) & TVN_MASK;
vec = base->tv4.vec + i;
} else if ((signed long) idx < 0)
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