Re: [PATCH v2 3/3] hw/openrisc/pic_cpu: Use qdev gpio rather than qemu_allocate_irqs()

[Peter Maydell]

On Tue, 12 May 2020 at 08:48, Philippe Mathieu-Daudé <address@hidden> wrote:
>
> Coverity points out (CID 1421934) that we are leaking the
> memory returned by qemu_allocate_irqs(). We can avoid this
> leak by switching to using qdev_init_gpio_in(); the base
> class finalize will free the irqs that this allocates under
> the hood.

>  hw/openrisc/pic_cpu.c | 5 ++---
>  1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/hw/openrisc/pic_cpu.c b/hw/openrisc/pic_cpu.c
> index 36f9350830..4b0c92f842 100644
> --- a/hw/openrisc/pic_cpu.c
> +++ b/hw/openrisc/pic_cpu.c
> @@ -52,10 +52,9 @@ static void openrisc_pic_cpu_handler(void *opaque, int 
> irq, int level)
>  void cpu_openrisc_pic_init(OpenRISCCPU *cpu)
>  {
>      int i;
> -    qemu_irq *qi;
> -    qi = qemu_allocate_irqs(openrisc_pic_cpu_handler, cpu, NR_IRQS);
> +    qdev_init_gpio_in(DEVICE(cpu), openrisc_pic_cpu_handler, NR_IRQS);
>
>      for (i = 0; i < NR_IRQS; i++) {
> -        cpu->env.irq[i] = qi[i];
> +        cpu->env.irq[i] = qdev_get_gpio_in(DEVICE(cpu), i);
>      }
>  }

This isn't wrong as such, but it's a bit weird, because it's code
outside of a device adding GPIO lines to that device, and the
handler function openrisc_pic_cpu_handler() is basically doing
nothing but reaching into the internals of the CPU device and
changing it.

Ideally:
 * all this code should be in target/openrisc/cpu.c, the same
   way the arm CPU creates its own inbound IRQs with qdev_init_gpio_in()
 * cpu->env.irq[] should go away, and hw/openrisc/openrisc_sim.c
   should be calling qdev_get_gpio_in() to get each IRQ line
   it needs, rather than directly grabbing cpu->env.irq and then
   indexing into it

But this change is an OK first step and we can build the other
cleanup on top of it, so
Reviewed-by: Peter Maydell <address@hidden>

thanks
-- PMM