On Fri, 1 Jul 2011 16:13:41 +0200
Fabien Chouteau <chout...@adacore.com> wrote:
> +uint64_t cpu_ppc_get_tb(ppc_tb_t *tb_env, uint64_t vmclk, int64_t tb_offset)
> {
> /* TB time in tb periods */
> return muldiv64(vmclk, tb_env->tb_freq, get_ticks_per_sec()) + tb_offset;
> @@ -678,18 +661,23 @@ static void __cpu_ppc_store_decr (CPUState *env,
> uint64_t *nextp,
> decr, value);
> now = qemu_get_clock_ns(vm_clock);
> next = now + muldiv64(value, get_ticks_per_sec(), tb_env->decr_freq);
> - if (is_excp)
> + if (is_excp) {
> next += *nextp - now;
> - if (next == now)
> + }
> + if (next == now) {
> next++;
> + }
> *nextp = next;
> /* Adjust timer */
> qemu_mod_timer(timer, next);
> /* If we set a negative value and the decrementer was positive,
> - * raise an exception.
> + * raise an exception (not for booke).
> */
> - if ((value & 0x80000000) && !(decr & 0x80000000))
> + if (! (env->insns_flags & PPC_BOOKE)
> + && (value & 0x80000000)
> + && !(decr & 0x80000000)) {
> (*raise_excp)(env);
> + }
> }
>
Also, load_decr should go from this:
if (diff >= 0)
decr = muldiv64(diff, tb_env->decr_freq, get_ticks_per_sec());
else
decr = -muldiv64(-diff, tb_env->decr_freq, get_ticks_per_sec());
to something like this:
if (diff >= 0) {
decr = muldiv64(diff, tb_env->decr_freq, get_ticks_per_sec());
} else if (env->insns_flags & PPC_BOOKE) {
decr = 0;
} else {
decr = -muldiv64(-diff, tb_env->decr_freq, get_ticks_per_sec());
}
> +/* Return the location of the bit of time base at which the FIT will raise an
> + interrupt */
> +static uint8_t booke_get_fit_target(CPUState *env)
> +{
> + uint8_t fp = (env->spr[SPR_BOOKE_TCR] & TCR_FP_MASK) >> TCR_FP_SHIFT;
> +
> + /* Only for e500 */
> + if (env->insns_flags2 & PPC2_E500) {
> + uint32_t fpext = (env->spr[SPR_BOOKE_TCR] & TCR_E500_FPEXT_MASK)
> + >> TCR_E500_FPEXT_SHIFT;
> + fp |= fpext << 2;
> + } else {
> + fp = env->fit_period[fp];
> + }
> +
> + return fp;
> +}
> +
> +/* Return the location of the bit of time base at which the WDT will raise an
> + interrupt */
> +static uint8_t booke_get_wdt_target(CPUState *env)
> +{
> + uint8_t wp = (env->spr[SPR_BOOKE_TCR] & TCR_WP_MASK) >> TCR_WP_SHIFT;
> +
> + /* Only for e500 */
> + if (env->insns_flags2 & PPC2_E500) {
> + uint32_t wpext = (env->spr[SPR_BOOKE_TCR] & TCR_E500_WPEXT_MASK)
> + >> TCR_E500_WPEXT_SHIFT;
> + wp |= wpext << 2;
> + } else {
> + wp = env->wdt_period[wp];
> + }
> +
> + return wp;
> +}
e500 fp/wp is expressed as bits from the MSB side of TB, so we need to
subtract from 63 to get something sane -- and document that fit/wdt_period
is from the LSB side.
> +static void booke_update_fixed_timer(CPUState *env,
> + uint8_t target_bit,
> + uint64_t *next,
> + struct QEMUTimer *timer)
> +{
> + ppc_tb_t *tb_env = env->tb_env;
> + uint64_t lapse;
> + uint64_t tb;
> + uint64_t period = 1 << (target_bit + 1);
> + uint64_t now;
> +
> + now = qemu_get_clock_ns(vm_clock);
> + tb = cpu_ppc_get_tb(tb_env, now, tb_env->tb_offset);
> +
> + if (tb <= (1 << target_bit)) {
> + lapse = (1 << target_bit) - tb;
> + } else {
> + lapse = period - ((tb - (1 << target_bit)) % period);
We know period is a power of two, so just do "& (period - 1)".
That should let you get rid of the special case for
"tb <= (1 << target_bit)" as well.
-Scott
