Re: [RFC PATCH v2 8/9] sparc/sun4m: Use one cpu_reset() function for main and secondary CPUs

[Philippe Mathieu-Daudé]

On 7/22/20 5:50 AM, Thiago Jung Bauermann wrote:
> If we rely on cpu_common_reset() setting CPUState::halted according to the
> start-powered-off property, both reset functions become equivalent and we
> can use only one.
> 
> Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
> ---
>  hw/sparc/sun4m.c | 21 ++++-----------------
>  1 file changed, 4 insertions(+), 17 deletions(-)
> 
> NB: I was only able to test that this patch builds. I wasn't able to
> run it.
> 
> diff --git a/hw/sparc/sun4m.c b/hw/sparc/sun4m.c
> index 7b3042a801..deb5e9f027 100644
> --- a/hw/sparc/sun4m.c
> +++ b/hw/sparc/sun4m.c
> @@ -218,16 +218,7 @@ static void dummy_cpu_set_irq(void *opaque, int irq, int 
> level)
>  {
>  }
>  
> -static void main_cpu_reset(void *opaque)
> -{
> -    SPARCCPU *cpu = opaque;
> -    CPUState *cs = CPU(cpu);
> -
> -    cpu_reset(cs);
> -    cs->halted = 0;
> -}
> -
> -static void secondary_cpu_reset(void *opaque)
> +static void sun4m_cpu_reset(void *opaque)
>  {
>      SPARCCPU *cpu = opaque;
>      CPUState *cs = CPU(cpu);
> @@ -818,7 +809,6 @@ static const TypeInfo ram_info = {
>  static void cpu_devinit(const char *cpu_type, unsigned int id,
>                          uint64_t prom_addr, qemu_irq **cpu_irqs)
>  {
> -    CPUState *cs;
>      SPARCCPU *cpu;
>      CPUSPARCState *env;
>  
> @@ -826,12 +816,9 @@ static void cpu_devinit(const char *cpu_type, unsigned 
> int id,
>      env = &cpu->env;
>  
>      cpu_sparc_set_id(env, id);
> -    if (id == 0) {
> -        qemu_register_reset(main_cpu_reset, cpu);

IMO it is easier to review this patch in 2, first drop main_cpu_reset
as it is pointless (we rely on cpu_common_reset), then set the
"start-powered-off" property and drop secondary_cpu_reset().

> -    } else {
> -        qemu_register_reset(secondary_cpu_reset, cpu);
> -        cs = CPU(cpu);
> -        object_property_set_bool(OBJECT(cs), "start-powered-off", true,
> +    qemu_register_reset(sun4m_cpu_reset, cpu);

Why do you still keep it?

> +    if (id != 0) {
> +        object_property_set_bool(OBJECT(cpu), "start-powered-off", true,
>                                   &error_abort);

At this point the CPU is realized, so this is correct.

I'd use directly:

       object_property_set_bool(OBJECT(cpu), "start-powered-off", !!id,
                                &error_abort);

>      }
>      *cpu_irqs = qemu_allocate_irqs(cpu_set_irq, cpu, MAX_PILS);
>