diff mbox series

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

Message ID 20200722035016.469075-9-bauerman@linux.ibm.com
State New
Headers show
Series Generalize start-powered-off property from ARM | expand

Commit Message

Thiago Jung Bauermann July 22, 2020, 3:50 a.m. UTC 
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.

Comments

Philippe Mathieu-Daudé July 22, 2020, 7:22 a.m. UTC | #1 
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);
>
Thiago Jung Bauermann July 23, 2020, 12:48 a.m. UTC | #2 
Philippe Mathieu-Daudé <philmd@redhat.com> writes:

> 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().

That's a good idea. I made those patches for v3.

>> -    } 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?

I didn't know that not registering a reset function would cause
cpu_reset() to be caused.

>> +    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.

Great. Thanks for confirming!

> I'd use directly:
>
>        object_property_set_bool(OBJECT(cpu), "start-powered-off", !!id,
>                                 &error_abort);

I used a slight variation of your suggestion, with `id != 0` instead of
`!!id` because I think it makes the code easier to read.

--
Thiago Jung Bauermann
IBM Linux Technology Center
diff mbox series

Patch

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);
-    } 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);
+    if (id != 0) {
+        object_property_set_bool(OBJECT(cpu), "start-powered-off", true,
                                  &error_abort);
     }
     *cpu_irqs = qemu_allocate_irqs(cpu_set_irq, cpu, MAX_PILS);