Re: [RFC PATCH 1/2] target/alpha: Expose TMR and SMP IRQ lines via QDev

[Peter Maydell]

On Tue, 20 Feb 2024 at 19:28, Philippe Mathieu-Daudé <philmd@linaro.org> wrote:
>
> In order to remove calls to cpu_interrupt() from hw/ code,
> expose the TMR and SMP interrupts via QDev as named GPIOs.
>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> ---
>  target/alpha/cpu.c | 30 ++++++++++++++++++++++++++++++
>  1 file changed, 30 insertions(+)
>
> diff --git a/target/alpha/cpu.c b/target/alpha/cpu.c
> index bf70173a25..619cd54593 100644
> --- a/target/alpha/cpu.c
> +++ b/target/alpha/cpu.c
> @@ -25,6 +25,31 @@
>  #include "cpu.h"
>  #include "exec/exec-all.h"
>
> +#ifndef CONFIG_USER_ONLY
> +static void alpha_cpu_tmr_irq(void *opaque, int irq, int level)
> +{
> +    DeviceState *dev = opaque;
> +    CPUState *cs = CPU(dev);
> +
> +    if (level) {
> +        cs->interrupt_request |= CPU_INTERRUPT_TIMER;
> +    } else {
> +        cs->interrupt_request &= ~CPU_INTERRUPT_TIMER;
> +    }

These should call cpu_interrupt(), because otherwise you
lose the logic that does a cpu-kick if one CPU triggers
an interrupt on another. (Also you lose the handling for
non-TCG accelerators, not that that's an issue for Alpha.)
Compare arm_cpu_set_irq().

thanks
-- PMM