Re: [Qemu-arm] [PATCH v5 13/13] target/arm: Send interrupts on PMU counter overflow

[Peter Maydell]

On 22 June 2018 at 21:32, Aaron Lindsay <address@hidden> wrote:
> Setup a QEMUTimer to get a callback when we expect counters to next
> overflow and trigger an interrupt at that time.
>
> Signed-off-by: Aaron Lindsay <address@hidden>
> ---
>  target/arm/cpu.c    |  11 +++++
>  target/arm/cpu.h    |   7 +++
>  target/arm/helper.c | 132 
> ++++++++++++++++++++++++++++++++++++++++++++++++----
>  3 files changed, 141 insertions(+), 9 deletions(-)
>
> diff --git a/target/arm/cpu.c b/target/arm/cpu.c
> index 2f5b16a..7b3c137 100644
> --- a/target/arm/cpu.c
> +++ b/target/arm/cpu.c
> @@ -743,6 +743,12 @@ static void arm_cpu_finalizefn(Object *obj)
>          QLIST_REMOVE(hook, node);
>          g_free(hook);
>      }
> +#ifndef CONFIG_USER_ONLY
> +    if (arm_feature(&cpu->env, ARM_FEATURE_PMU)) {
> +        timer_deinit(cpu->pmu_timer);
> +        timer_free(cpu->pmu_timer);
> +    }
> +#endif
>  }
>
>  static void arm_cpu_realizefn(DeviceState *dev, Error **errp)
> @@ -937,6 +943,11 @@ static void arm_cpu_realizefn(DeviceState *dev, Error 
> **errp)
>              arm_register_pre_el_change_hook(cpu, &pmu_pre_el_change, 0);
>              arm_register_el_change_hook(cpu, &pmu_post_el_change, 0);
>          }
> +
> +#ifndef CONFIG_USER_ONLY
> +        cpu->pmu_timer = timer_new(QEMU_CLOCK_VIRTUAL, 1, arm_pmu_timer_cb,
> +                cpu);

This is a confusing way to write timer_new_ns().

> +#endif

>  #define SUPPORTED_EVENT_SENTINEL UINT16_MAX
>  static const pm_event pm_events[] = {
>      { .number = 0x000, /* SW_INCR */
>        .supported = event_always_supported,
> -      .get_count = swinc_get_count
> +      .get_count = swinc_get_count,
> +      .ns_per_count = swinc_ns_per

If you always put trailing commas on the end of the last line in
a struct initializer, then you don't need to modify the preceding
line in later patches which add a new line to the initializer.

The meat of the patch is beyond me at this time of the
afternoon :-)

thanks
-- PMM