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hw/ppc: Introduce functions for conversion between timebase and nanoseconds

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These calculations are repeated several times, and they will become
a little more complicated with subsequent changes.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
(cherry picked from commit 7798f5c576)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
This commit is contained in:
Nicholas Piggin 2023-08-08 14:19:46 +10:00 committed by Michael Tokarev
parent 6bb4a8a47a
commit ded5edee00
1 changed files with 18 additions and 10 deletions
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28
hw/ppc/ppc.c
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@ -482,10 +482,20 @@ void ppce500_set_mpic_proxy(bool enabled)
/*****************************************************************************/
/* PowerPC time base and decrementer emulation */
static uint64_t ns_to_tb(uint32_t freq, int64_t clock)
{
return muldiv64(clock, freq, NANOSECONDS_PER_SECOND);
}
static int64_t tb_to_ns(uint32_t freq, uint64_t tb)
{
return muldiv64(tb, NANOSECONDS_PER_SECOND, freq);
}
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, NANOSECONDS_PER_SECOND) + tb_offset;
return ns_to_tb(tb_env->tb_freq, vmclk) + tb_offset;
}
uint64_t cpu_ppc_load_tbl (CPUPPCState *env)
@ -526,8 +536,7 @@ uint32_t cpu_ppc_load_tbu (CPUPPCState *env)
static inline void cpu_ppc_store_tb(ppc_tb_t *tb_env, uint64_t vmclk,
int64_t *tb_offsetp, uint64_t value)
{
*tb_offsetp = value -
muldiv64(vmclk, tb_env->tb_freq, NANOSECONDS_PER_SECOND);
*tb_offsetp = value - ns_to_tb(tb_env->tb_freq, vmclk);
trace_ppc_tb_store(value, *tb_offsetp);
}
@ -690,11 +699,11 @@ static inline int64_t _cpu_ppc_load_decr(CPUPPCState *env, uint64_t next)
diff = next - qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
if (diff >= 0) {
decr = muldiv64(diff, tb_env->decr_freq, NANOSECONDS_PER_SECOND);
decr = ns_to_tb(tb_env->decr_freq, diff);
} else if (tb_env->flags & PPC_TIMER_BOOKE) {
decr = 0;
} else {
decr = -muldiv64(-diff, tb_env->decr_freq, NANOSECONDS_PER_SECOND);
decr = -ns_to_tb(tb_env->decr_freq, -diff);
}
trace_ppc_decr_load(decr);
@ -834,7 +843,7 @@ static void __cpu_ppc_store_decr(PowerPCCPU *cpu, uint64_t *nextp,
/* Calculate the next timer event */
now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
next = now + muldiv64(value, NANOSECONDS_PER_SECOND, tb_env->decr_freq);
next = now + tb_to_ns(tb_env->decr_freq, value);
*nextp = next;
/* Adjust timer */
@ -1125,7 +1134,7 @@ static void cpu_4xx_fit_cb (void *opaque)
/* Cannot occur, but makes gcc happy */
return;
}
next = now + muldiv64(next, NANOSECONDS_PER_SECOND, tb_env->tb_freq);
next = now + tb_to_ns(tb_env->tb_freq, next);
if (next == now)
next++;
timer_mod(ppc40x_timer->fit_timer, next);
@ -1153,8 +1162,7 @@ static void start_stop_pit (CPUPPCState *env, ppc_tb_t *tb_env, int is_excp)
} else {
trace_ppc4xx_pit_start(ppc40x_timer->pit_reload);
now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
next = now + muldiv64(ppc40x_timer->pit_reload,
NANOSECONDS_PER_SECOND, tb_env->decr_freq);
next = now + tb_to_ns(tb_env->decr_freq, ppc40x_timer->pit_reload);
if (is_excp)
next += tb_env->decr_next - now;
if (next == now)
@ -1213,7 +1221,7 @@ static void cpu_4xx_wdt_cb (void *opaque)
/* Cannot occur, but makes gcc happy */
return;
}
next = now + muldiv64(next, NANOSECONDS_PER_SECOND, tb_env->decr_freq);
next = now + tb_to_ns(tb_env->decr_freq, next);
if (next == now)
next++;
trace_ppc4xx_wdt(env->spr[SPR_40x_TCR], env->spr[SPR_40x_TSR]);