Re: [Qemu-devel] [PATCH] fix disabling interrupts in sun4u

[Artyom Tarasenko]

On Thu, Jul 28, 2011 at 2:10 PM, Tsuneo Saito <address@hidden> wrote:
> 2011/7/28 <address@hidden>:
>>
>> At Thu, 28 Jul 2011 13:51:08 +0200,
>> Artyom Tarasenko wrote:
>> > On Thu, Jul 28, 2011 at 12:31 PM,  <address@hidden> wrote:
>> > > Hi,
>> > >
>> > > At Mon, 25 Jul 2011 19:22:38 +0200,
>> > > Artyom Tarasenko wrote:
>> > >
>> > >> clear interrupt request if the interrupt priority < CPU pil
>> > >> clear hardware interrupt request if interrupts are disabled
>> > >
>> > > Not directly related to the fix, but I'd like to note a problem
>> > > of hw/sun4u.c interrupt code:
>> > >
>> > > The interrupt code probably mixes hardware interrupts and
>> > > software interrupts.
>> > > %pil is for software interrupts (interrupt_level_n traps).
>> > > %pil can not mask hardware interrupts (interrupt_vector traps);
>> > > the CPU raises interrupt_vector traps even on %pil=15.
>> > > But in cpu_check_irqs() and cpu_set_irq(), hardware interrupts
>> > > seem to be masked by %pil.
>> >
>> > The interrupt_vector traps are currently not implemented, are they?
>> > So it's hard to tell whether they are masked.
>>
>> Yes, interrupt_vector is not implemented yet.
>
> Ah, I intended to write:
>  No, interrupt_vector is not implemented yet.
> I'm very sorry for my engrish :-(

Not having English as my native language, I even haven't noticed
something wrong here.

Despite what they say the International language is not English, but
broken English.  :)

>> I failed to explain the problem.
>> The problem is that cpu_set_irqs() should raise interrupt_vector
>> traps but it raises interrupt_level_n traps actually.
>>
>> sun4uv_init() calls qemu_allocate_irqs() with cpu_set_irq as
>> the 1st argument.  The allocated irqs (the irq variable) are
>> passed to pci_apb_init().  APB should generate interrupt_vector
>> traps (hardware interrupts), not the interrupt_vector_n traps.
>> The interrupts from APB would be reported by cpu_set_irq(),
>> but cpu_set_irq() seems to generate interrupt_vector_n traps.
>>
>> > >> Signed-off-by: Artyom Tarasenko <address@hidden>
>> > >> ---
>> > >>  hw/sun4u.c |    6 ++++--
>> > >>  1 files changed, 4 insertions(+), 2 deletions(-)
>> > >>
>> > >> diff --git a/hw/sun4u.c b/hw/sun4u.c
>> > >> index d7dcaf0..7f95aeb 100644
>> > >> --- a/hw/sun4u.c
>> > >> +++ b/hw/sun4u.c
>> > >> @@ -255,7 +255,7 @@ void cpu_check_irqs(CPUState *env)
>> > >>          pil |= 1 << 14;
>> > >>      }
>> > >>
>> > >> -    if (!pil) {
>> > >> +    if (pil < (2 << env->psrpil)){
>> > >>          if (env->interrupt_request & CPU_INTERRUPT_HARD) {
>> > >>              CPUIRQ_DPRINTF("Reset CPU IRQ (current interrupt %x)\n",
>> > >>                             env->interrupt_index);
>> > >> @@ -287,10 +287,12 @@ void cpu_check_irqs(CPUState *env)
>> > >>                  break;
>> > >>              }
>> > >>          }
>> > >> -    } else {
>> > >> +    } else if (env->interrupt_request & CPU_INTERRUPT_HARD) {
>> > >>          CPUIRQ_DPRINTF("Interrupts disabled, pil=%08x pil_in=%08x 
>> > >> softint=%08x "
>> > >>                         "current interrupt %x\n",
>> > >>                         pil, env->pil_in, env->softint, 
>> > >> env->interrupt_index);
>> > >> +        env->interrupt_index = 0;
>> > >> +        cpu_reset_interrupt(env, CPU_INTERRUPT_HARD);
>> > >>      }
>> > >>  }
>> > >>
>> > >> --
>> > >> 1.7.3.4
>> > >
>> > >
>> > > ----
>> > > Tsuneo Saito <address@hidden>
>> > >
>> >
>> >
>> >
>> > --
>> > Regards,
>> > Artyom Tarasenko
>> >
>> > solaris/sparc under qemu blog: http://tyom.blogspot.com/
>>
>> ----
>> Tsuneo Saito <address@hidden>
>



-- 
Regards,
Artyom Tarasenko

solaris/sparc under qemu blog: http://tyom.blogspot.com/