/*
 * Common time prototypes and such for all ppc machines.
 *
 * Written by Cort Dougan (cort@cs.nmt.edu) to merge
 * Paul Mackerras' version and mine for PReP and Pmac.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */

#ifndef __POWERPC_TIME_H
#define __POWERPC_TIME_H

#ifdef __KERNEL__
#include <linux/types.h>
#include <linux/percpu.h>

#include <asm/processor.h>
#include <asm/cpu_has_feature.h>

/* time.c */
extern unsigned long tb_ticks_per_jiffy;
extern unsigned long tb_ticks_per_usec;
extern unsigned long tb_ticks_per_sec;
extern struct clock_event_device decrementer_clockevent;

struct rtc_time;
extern void to_tm(int tim, struct rtc_time * tm);
extern void tick_broadcast_ipi_handler(void);

extern void generic_calibrate_decr(void);
extern void hdec_interrupt(struct pt_regs *regs);

/* Some sane defaults: 125 MHz timebase, 1GHz processor */
extern unsigned long ppc_proc_freq;
#define DEFAULT_PROC_FREQ       (DEFAULT_TB_FREQ * 8)
extern unsigned long ppc_tb_freq;
#define DEFAULT_TB_FREQ         125000000UL

struct div_result {
        u64 result_high;
        u64 result_low;
};

/* Accessor functions for the timebase (RTC on 601) registers. */
/* If one day CONFIG_POWER is added just define __USE_RTC as 1 */
#ifdef CONFIG_6xx
#define __USE_RTC()     (cpu_has_feature(CPU_FTR_USE_RTC))
#else
#define __USE_RTC()     0
#endif

#ifdef CONFIG_PPC64

/* For compatibility, get_tbl() is defined as get_tb() on ppc64 */
#define get_tbl         get_tb

#else

static inline unsigned long get_tbl(void)
{
#if defined(CONFIG_403GCX)
        unsigned long tbl;
        asm volatile("mfspr %0, 0x3dd" : "=r" (tbl));
        return tbl;
#else
        return mftbl();
#endif
}

static inline unsigned int get_tbu(void)
{
#ifdef CONFIG_403GCX
        unsigned int tbu;
        asm volatile("mfspr %0, 0x3dc" : "=r" (tbu));
        return tbu;
#else
        return mftbu();
#endif
}
#endif /* !CONFIG_PPC64 */

static inline unsigned int get_rtcl(void)
{
        unsigned int rtcl;

        asm volatile("mfrtcl %0" : "=r" (rtcl));
        return rtcl;
}

static inline u64 get_rtc(void)
{
        unsigned int hi, lo, hi2;

        do {
                asm volatile("mfrtcu %0; mfrtcl %1; mfrtcu %2"
                             : "=r" (hi), "=r" (lo), "=r" (hi2));
        } while (hi2 != hi);
        return (u64)hi * 1000000000 + lo;
}

static inline u64 get_vtb(void)
{
#ifdef CONFIG_PPC_BOOK3S_64
        if (cpu_has_feature(CPU_FTR_ARCH_207S))
                return mfspr(SPRN_VTB);
#endif
        return 0;
}

#ifdef CONFIG_PPC64
static inline u64 get_tb(void)
{
        return mftb();
}
#else /* CONFIG_PPC64 */
static inline u64 get_tb(void)
{
        unsigned int tbhi, tblo, tbhi2;

        do {
                tbhi = get_tbu();
                tblo = get_tbl();
                tbhi2 = get_tbu();
        } while (tbhi != tbhi2);

        return ((u64)tbhi << 32) | tblo;
}
#endif /* !CONFIG_PPC64 */

static inline u64 get_tb_or_rtc(void)
{
        return __USE_RTC() ? get_rtc() : get_tb();
}

static inline void set_tb(unsigned int upper, unsigned int lower)
{
        mtspr(SPRN_TBWL, 0);
        mtspr(SPRN_TBWU, upper);
        mtspr(SPRN_TBWL, lower);
}

/* Accessor functions for the decrementer register.
 * The 4xx doesn't even have a decrementer.  I tried to use the
 * generic timer interrupt code, which seems OK, with the 4xx PIT
 * in auto-reload mode.  The problem is PIT stops counting when it
 * hits zero.  If it would wrap, we could use it just like a decrementer.
 */
static inline u64 get_dec(void)
{
#if defined(CONFIG_40x)
        return (mfspr(SPRN_PIT));
#else
        return (mfspr(SPRN_DEC));
#endif
}

/*
 * Note: Book E and 4xx processors differ from other PowerPC processors
 * in when the decrementer generates its interrupt: on the 1 to 0
 * transition for Book E/4xx, but on the 0 to -1 transition for others.
 */
static inline void set_dec(u64 val)
{
#if defined(CONFIG_40x)
        mtspr(SPRN_PIT, (u32) val);
#else
#ifndef CONFIG_BOOKE
        --val;
#endif
        mtspr(SPRN_DEC, val);
#endif /* not 40x */
}

static inline unsigned long tb_ticks_since(unsigned long tstamp)
{
        if (__USE_RTC()) {
                int delta = get_rtcl() - (unsigned int) tstamp;
                return delta < 0 ? delta + 1000000000 : delta;
        }
        return get_tbl() - tstamp;
}

#define mulhwu(x,y) \
({unsigned z; asm ("mulhwu %0,%1,%2" : "=r" (z) : "r" (x), "r" (y)); z;})

#ifdef CONFIG_PPC64
#define mulhdu(x,y) \
({unsigned long z; asm ("mulhdu %0,%1,%2" : "=r" (z) : "r" (x), "r" (y)); z;})
#else
extern u64 mulhdu(u64, u64);
#endif

extern void div128_by_32(u64 dividend_high, u64 dividend_low,
                         unsigned divisor, struct div_result *dr);

/* Used to store Processor Utilization register (purr) values */

struct cpu_usage {
        u64 current_tb;  /* Holds the current purr register values */
};

DECLARE_PER_CPU(struct cpu_usage, cpu_usage_array);

extern void secondary_cpu_time_init(void);
extern void __init time_init(void);

DECLARE_PER_CPU(u64, decrementers_next_tb);

/* Convert timebase ticks to nanoseconds */
unsigned long long tb_to_ns(unsigned long long tb_ticks);

#endif /* __KERNEL__ */
#endif /* __POWERPC_TIME_H */