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target/mips/cpu: Allow the CPU to use dynamic frequencies

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Use the Clock API and let the CPU object have an input clock.

If no clock is connected, keep using the default frequency of
200 MHz used since the introduction of the 'r4k' machine in
commit 6af0bf9c7c.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20201012095804.3335117-12-f4bug@amsat.org>
This commit is contained in:
Philippe Mathieu-Daudé 2020-10-12 11:57:54 +02:00
parent d0bec217ee
commit a0713e85bf
2 changed files with 13 additions and 2 deletions
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11
target/mips/cpu.c
View file

@ -27,6 +27,7 @@
#include "sysemu/kvm.h"
#include "exec/exec-all.h"
#include "hw/qdev-properties.h"
#include "hw/qdev-clock.h"
static void mips_cpu_set_pc(CPUState *cs, vaddr value)
{
@ -144,8 +145,9 @@ static void mips_cp0_period_set(MIPSCPU *cpu)
{
CPUMIPSState *env = &cpu->env;
env->cp0_count_ns = muldiv64(NANOSECONDS_PER_SECOND, cpu->cp0_count_rate,
CPU_FREQ_HZ_DEFAULT);
env->cp0_count_ns = cpu->cp0_count_rate
* clock_get_ns(MIPS_CPU(cpu)->clock);
assert(env->cp0_count_ns);
}
static void mips_cpu_realizefn(DeviceState *dev, Error **errp)
@ -155,6 +157,10 @@ static void mips_cpu_realizefn(DeviceState *dev, Error **errp)
MIPSCPUClass *mcc = MIPS_CPU_GET_CLASS(dev);
Error *local_err = NULL;
if (!clock_get(cpu->clock)) {
/* Initialize the frequency in case the clock remains unconnected. */
clock_set_hz(cpu->clock, CPU_FREQ_HZ_DEFAULT);
}
mips_cp0_period_set(cpu);
cpu_exec_realizefn(cs, &local_err);
@ -178,6 +184,7 @@ static void mips_cpu_initfn(Object *obj)
MIPSCPUClass *mcc = MIPS_CPU_GET_CLASS(obj);
cpu_set_cpustate_pointers(cpu);
cpu->clock = qdev_init_clock_in(DEVICE(obj), "clk-in", NULL, cpu);
env->cpu_model = mcc->cpu_def;
}

4
target/mips/cpu.h
View file

@ -4,6 +4,7 @@
#include "cpu-qom.h"
#include "exec/cpu-defs.h"
#include "fpu/softfloat-types.h"
#include "hw/clock.h"
#include "mips-defs.h"
#define TCG_GUEST_DEFAULT_MO (0)
@ -1151,6 +1152,8 @@ struct CPUMIPSState {
/**
* MIPSCPU:
* @env: #CPUMIPSState
* @clock: this CPU input clock (may be connected
* to an output clock from another device).
* @cp0_count_rate: rate at which the coprocessor 0 counter increments
*
* A MIPS CPU.
@ -1160,6 +1163,7 @@ struct MIPSCPU {
CPUState parent_obj;
/*< public >*/
Clock *clock;
CPUNegativeOffsetState neg;
CPUMIPSState env;
/*