[PATCH 3/8] drm/amdkfd: Avoid calling amd_iommu_unbind_pasid() when suspending

[Oded Gabbay]

On Thu, Oct 26, 2017 at 1:41 AM, Felix Kuehling <Felix.Kuehling at amd.com> wrote:
> From: Yong Zhao <yong.zhao at amd.com>
>
> When kfd suspending on APU, we do not need to call
> amd_iommu_unbind_pasid(), because pasid will be unbound automatically
> when power goes off.
>
> On the other hand, calling amd_iommu_unbind_pasid() will trigger
> kfd_process_iommu_unbind_callback() if the process is not terminating.
> By design, kfd_process_iommu_unbind_callback() should only be called
> for process terminating. So we would rather not to call
> amd_iommu_unbind_pasid() when suspending.
>
> Signed-off-by: Yong Zhao <yong.zhao at amd.com>
> Signed-off-by: Felix Kuehling <Felix.Kuehling at amd.com>
> ---
>  drivers/gpu/drm/amd/amdkfd/kfd_process.c | 14 +++++---------
>  1 file changed, 5 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_process.c b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
> index f871855..5d93a5c 100644
> --- a/drivers/gpu/drm/amd/amdkfd/kfd_process.c
> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
> @@ -428,29 +428,25 @@ int kfd_bind_processes_to_device(struct kfd_dev *dev)
>  }
>
>  /*
> - * Temporarily unbind currently bound processes from the device and
> - * mark them as PDD_BOUND_SUSPENDED. These processes will be restored
> - * to PDD_BOUND state in kfd_bind_processes_to_device.
> + * Mark currently bound processes as PDD_BOUND_SUSPENDED. These
> + * processes will be restored to PDD_BOUND state in
> + * kfd_bind_processes_to_device.
>   */
>  void kfd_unbind_processes_from_device(struct kfd_dev *dev)
>  {
>         struct kfd_process_device *pdd;
>         struct kfd_process *p;
> -       unsigned int temp, temp_bound, temp_pasid;
> +       unsigned int temp;
>
>         int idx = srcu_read_lock(&kfd_processes_srcu);
>
>         hash_for_each_rcu(kfd_processes_table, temp, p, kfd_processes) {
>                 mutex_lock(&p->mutex);
>                 pdd = kfd_get_process_device_data(dev, p);
> -               temp_bound = pdd->bound;
> -               temp_pasid = p->pasid;
> +
>                 if (pdd->bound == PDD_BOUND)
>                         pdd->bound = PDD_BOUND_SUSPENDED;
>                 mutex_unlock(&p->mutex);
> -
> -               if (temp_bound == PDD_BOUND)
> -                       amd_iommu_unbind_pasid(dev->pdev, temp_pasid);
>         }
>
>         srcu_read_unlock(&kfd_processes_srcu, idx);
> --
> 2.7.4
>
This patch is:
Reviewed-by: Oded Gabbay <oded.gabbay at gmail.com>