On Mon, 15 Dec 2025 11:54:56 +0000
Lukas Zapolskas <[email protected]> wrote:

> Receiving an MMU fault currently disables the AS, so each of the groups
> is marked with the appropriate faults. Since no further submissions
> can occur on a fatal fault for that group, the fault information
> does not have to be cleared until the group is terminated.
> 
> Signed-off-by: Lukas Zapolskas <[email protected]>
> ---
>  drivers/gpu/drm/panthor/panthor_mmu.c   |  8 ++++++++
>  drivers/gpu/drm/panthor/panthor_mmu.h   |  2 ++
>  drivers/gpu/drm/panthor/panthor_sched.c | 13 +++++++++++++
>  3 files changed, 23 insertions(+)
> 
> diff --git a/drivers/gpu/drm/panthor/panthor_mmu.c 
> b/drivers/gpu/drm/panthor/panthor_mmu.c
> index 10a7418eecda..9e78b0509f1a 100644
> --- a/drivers/gpu/drm/panthor/panthor_mmu.c
> +++ b/drivers/gpu/drm/panthor/panthor_mmu.c
> @@ -2895,3 +2895,11 @@ void panthor_mmu_pt_cache_fini(void)
>  {
>       kmem_cache_destroy(pt_cache);
>  }
> +
> +struct panthor_vm_fault *panthor_vm_get_fault(struct panthor_vm *vm)

const struct panthor_vm_fault *
panthor_vm_get_fault(struct panthor_vm *vm)

or

struct panthor_vm_fault
panthor_vm_get_fault(struct panthor_vm *vm)

or

void
panthor_vm_get_fault(struct panthor_vm *vm,
                     struct panthor_vm_fault *fault)

but you shouldn't let the caller with a writable pointer to vm->fault.

> +{
> +     if (!vm)
> +             return NULL;

I don't see a valid case where panthor_vm_get_fault() would be called
with a NULL pointer.

> +
> +     return &vm->fault;
> +}
> diff --git a/drivers/gpu/drm/panthor/panthor_mmu.h 
> b/drivers/gpu/drm/panthor/panthor_mmu.h
> index 023fdc79c231..d69b4000a39e 100644
> --- a/drivers/gpu/drm/panthor/panthor_mmu.h
> +++ b/drivers/gpu/drm/panthor/panthor_mmu.h
> @@ -123,4 +123,6 @@ void panthor_mmu_pt_cache_fini(void);
>  void panthor_mmu_debugfs_init(struct drm_minor *minor);
>  #endif
>  
> +struct panthor_vm_fault *panthor_vm_get_fault(struct panthor_vm *vm);
> +
>  #endif
> diff --git a/drivers/gpu/drm/panthor/panthor_sched.c 
> b/drivers/gpu/drm/panthor/panthor_sched.c
> index a77399e95620..9ea0d2b27114 100644
> --- a/drivers/gpu/drm/panthor/panthor_sched.c
> +++ b/drivers/gpu/drm/panthor/panthor_sched.c
> @@ -722,6 +722,11 @@ struct panthor_group {
>        * panthor_group::groups::waiting list.
>        */
>       struct list_head wait_node;
> +
> +     /**
> +      * @fatal: VM-level fault that caused a fatal error on the group.
> +      */
> +     struct panthor_vm_fault fatal;
>  };
>  
>  struct panthor_job_profiling_data {
> @@ -1575,6 +1580,14 @@ cs_slot_process_fatal_event_locked(struct 
> panthor_device *ptdev,
>                        group->task_info.pid, group->task_info.comm);
>  
>               group->fatal_queues |= BIT(cs_id);
> +
> +             if (panthor_vm_has_unhandled_faults(group->vm)) {
> +                     struct panthor_vm_fault *fault;
> +
> +                     fault = panthor_vm_get_fault(group->vm);
> +                     if (fault)
> +                             group->fatal = *fault;
> +             }
>       }
>  
>       if (CS_EXCEPTION_TYPE(fatal) == DRM_PANTHOR_EXCEPTION_CS_UNRECOVERABLE) 
> {

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