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hw/openrisc: Initialize timer time at startup

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The last_clk time was initialized at zero, this means when we calculate
the first delta we will calculate 0 vs current time which could cause
unnecessary hops.

This patch moves timer initialization to the cpu reset.  There are two
resets registered here:

 1. Per cpu timer mask (ttmr) reset.
 2. Global cpu timer (last_clk and ttcr) reset, attached to the first
    cpu only.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Stafford Horne <shorne@gmail.com>
This commit is contained in:
Stafford Horne 2022-06-15 08:40:16 +09:00
parent 40fef82c4e
commit 557e37071d
1 changed files with 21 additions and 1 deletions
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22
hw/openrisc/cputimer.c
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@ -22,6 +22,7 @@
#include "cpu.h"
#include "migration/vmstate.h"
#include "qemu/timer.h"
#include "sysemu/reset.h"
#define TIMER_PERIOD 50 /* 50 ns period for 20 MHz timer */
@ -122,6 +123,24 @@ static void openrisc_timer_cb(void *opaque)
qemu_cpu_kick(CPU(cpu));
}
/* Reset the per CPU counter state. */
static void openrisc_count_reset(void *opaque)
{
OpenRISCCPU *cpu = opaque;
if (cpu->env.is_counting) {
cpu_openrisc_count_stop(cpu);
}
cpu->env.ttmr = 0x00000000;
}
/* Reset the global timer state. */
static void openrisc_timer_reset(void *opaque)
{
or1k_timer->ttcr = 0x00000000;
or1k_timer->last_clk = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
}
static const VMStateDescription vmstate_or1k_timer = {
.name = "or1k_timer",
.version_id = 1,
@ -136,10 +155,11 @@ static const VMStateDescription vmstate_or1k_timer = {
void cpu_openrisc_clock_init(OpenRISCCPU *cpu)
{
cpu->env.timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, &openrisc_timer_cb, cpu);
cpu->env.ttmr = 0x00000000;
qemu_register_reset(openrisc_count_reset, cpu);
if (or1k_timer == NULL) {
or1k_timer = g_new0(OR1KTimerState, 1);
qemu_register_reset(openrisc_timer_reset, cpu);
vmstate_register(NULL, 0, &vmstate_or1k_timer, or1k_timer);
}
}