[PATCH 4/6] drm/amdgpu: Avoid use KIQ in VM fault ISR for SRIOV support

[Christian König]

Am 30.11.2016 um 08:02 schrieb Xiangliang Yu:
> Schedule a workqueue for VM fault handler on GMC V8.0 for SRIOV
> support.
>
> Signed-off-by: shaoyunl <Shaoyun.Liu at amd.com>
> Signed-off-by: Xiangliang Yu <Xiangliang.Yu at amd.com>

NAK, it is vital to print the information from the registers and reset 
them ASAP even under SRIOV.

My last status was that the registers in question shouldn't be subject 
to KIQ and accessed directly.

Christian.

> ---
>   drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c | 40 ++++++++++++++++++++++++++++++++++-
>   1 file changed, 39 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c
> index 0daac3a..e4a628c 100644
> --- a/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c
> @@ -1219,7 +1219,7 @@ static int gmc_v8_0_vm_fault_interrupt_state(struct amdgpu_device *adev,
>   	return 0;
>   }
>   
> -static int gmc_v8_0_process_interrupt(struct amdgpu_device *adev,
> +static int gmc_v8_0_process_vm_fault(struct amdgpu_device *adev,
>   				      struct amdgpu_irq_src *source,
>   				      struct amdgpu_iv_entry *entry)
>   {
> @@ -1250,6 +1250,44 @@ static int gmc_v8_0_process_interrupt(struct amdgpu_device *adev,
>   	return 0;
>   }
>   
> +struct gmc_vm_fault_work {
> +	struct work_struct	base;
> +	struct amdgpu_device	*adev;
> +	struct amdgpu_irq_src	*source;
> +	struct amdgpu_iv_entry	*entry;
> +};
> +
> +static void gmc_v8_0_vm_fault_sched(struct work_struct *work)
> +{
> +	struct gmc_vm_fault_work *vm_work =
> +		container_of(work, struct gmc_vm_fault_work, base);
> +	struct amdgpu_device *adev = vm_work->adev;
> +	struct amdgpu_irq_src *source = vm_work->source;
> +	struct amdgpu_iv_entry *entry = vm_work->entry;
> +
> +	gmc_v8_0_process_vm_fault(adev, source, entry);
> +	kfree(vm_work);
> +}
> +
> +static int gmc_v8_0_process_interrupt(struct amdgpu_device *adev,
> +				      struct amdgpu_irq_src *source,
> +				      struct amdgpu_iv_entry *entry)
> +{
> +	struct gmc_vm_fault_work *work = NULL;
> +
> +	if (amdgpu_sriov_vf(adev)) {
> +		work = kmalloc(sizeof(struct gmc_vm_fault_work), GFP_ATOMIC);
> +		if (!work)
> +			return -ENOMEM;
> +		INIT_WORK(&work->base, gmc_v8_0_vm_fault_sched);
> +		work->adev = adev;
> +		work->source = source;
> +		work->entry = entry;
> +		return schedule_work(&work->base);
> +	}
> +	return gmc_v8_0_process_vm_fault(adev, source, entry);
> +}
> +
>   static void fiji_update_mc_medium_grain_clock_gating(struct amdgpu_device *adev,
>   						     bool enable)
>   {