mips_timer.c
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#include "hw.h"
#include "mips.h"
#include "qemu-timer.h"
#define TIMER_FREQ 100 * 1000 * 1000
void cpu_mips_irqctrl_init (void)
{
}
/* XXX: do not use a global */
uint32_t cpu_mips_get_random (CPUState *env)
{
static uint32_t seed = 0;
uint32_t idx;
seed = seed * 314159 + 1;
idx = (seed >> 16) % (env->tlb->nb_tlb - env->CP0_Wired) + env->CP0_Wired;
return idx;
}
/* MIPS R4K timer */
uint32_t cpu_mips_get_count (CPUState *env)
{
if (env->CP0_Cause & (1 << CP0Ca_DC))
return env->CP0_Count;
else
return env->CP0_Count +
(uint32_t)muldiv64(qemu_get_clock(vm_clock),
TIMER_FREQ, ticks_per_sec);
}
static void cpu_mips_timer_update(CPUState *env)
{
uint64_t now, next;
uint32_t wait;
now = qemu_get_clock(vm_clock);
wait = env->CP0_Compare - env->CP0_Count -
(uint32_t)muldiv64(now, TIMER_FREQ, ticks_per_sec);
next = now + muldiv64(wait, ticks_per_sec, TIMER_FREQ);
qemu_mod_timer(env->timer, next);
}
void cpu_mips_store_count (CPUState *env, uint32_t count)
{
if (env->CP0_Cause & (1 << CP0Ca_DC))
env->CP0_Count = count;
else {
/* Store new count register */
env->CP0_Count =
count - (uint32_t)muldiv64(qemu_get_clock(vm_clock),
TIMER_FREQ, ticks_per_sec);
/* Update timer timer */
cpu_mips_timer_update(env);
}
}
void cpu_mips_store_compare (CPUState *env, uint32_t value)
{
env->CP0_Compare = value;
if (!(env->CP0_Cause & (1 << CP0Ca_DC)))
cpu_mips_timer_update(env);
if (env->insn_flags & ISA_MIPS32R2)
env->CP0_Cause &= ~(1 << CP0Ca_TI);
qemu_irq_lower(env->irq[(env->CP0_IntCtl >> CP0IntCtl_IPTI) & 0x7]);
}
void cpu_mips_start_count(CPUState *env)
{
cpu_mips_store_count(env, env->CP0_Count);
}
void cpu_mips_stop_count(CPUState *env)
{
/* Store the current value */
env->CP0_Count += (uint32_t)muldiv64(qemu_get_clock(vm_clock),
TIMER_FREQ, ticks_per_sec);
}
static void mips_timer_cb (void *opaque)
{
CPUState *env;
env = opaque;
#if 0
if (logfile) {
fprintf(logfile, "%s\n", __func__);
}
#endif
if (env->CP0_Cause & (1 << CP0Ca_DC))
return;
cpu_mips_timer_update(env);
if (env->insn_flags & ISA_MIPS32R2)
env->CP0_Cause |= 1 << CP0Ca_TI;
qemu_irq_raise(env->irq[(env->CP0_IntCtl >> CP0IntCtl_IPTI) & 0x7]);
}
void cpu_mips_clock_init (CPUState *env)
{
env->timer = qemu_new_timer(vm_clock, &mips_timer_cb, env);
env->CP0_Compare = 0;
cpu_mips_store_count(env, 1);
}