Re: [PATCH v3 2/2] iommu/arm-smmu-v3: Adopt arm_smmu_event in handlers

[Nicolin Chen <nicolinc@nvidia.com>]

On Sat, Sep 28, 2024 at 12:51:43AM +0000, Pranjal Shrivastava wrote:
>  /* IRQ and event handlers */
> -static int arm_smmu_handle_evt(struct arm_smmu_device *smmu, u64 *evt)
> +static int arm_smmu_handle_evt(struct arm_smmu_device *smmu, struct arm_smmu_event *event)

Looks like we could stuff an smmu pointer in the event:

struct arm_smmu_event {
+	struct arm_smmu_device *smmu;
	struct arm_smmu_master		*master;
	const char			*master_name;

Then both this arm_smmu_handle_evt and arm_smmu_dump_event can be
slightly cleaner.

> 
>         mutex_lock(&smmu->streams_mutex);
> -       master = arm_smmu_find_master(smmu, sid);
> -       if (!master) {
> +       event->master = arm_smmu_find_master(smmu, event->sid);
> +       if (!event->master) {
>                 ret = -EINVAL;
> +               event->master_name = "(unassigned sid)";
>                 goto out_unlock;
>         }

The PATCH-1 already did arm_smmu_find_master() to event->master in
arm_smmu_get_evt_info()?

Maybe we still need a wider mutex to lock arm_smmu_get_evt_info and
arm_smmu_handle_evt.

Thanks
Nicolin