[PATCH 2/2] drm/amdkfd: Decode bit fields in 'cik_ih_ring_entry' directly

[Christian König]

NAK, don't use bitfields to decode hardware values. They aren't portable.

Regards,
Christian.

Am 27.09.2016 um 14:47 schrieb Edward O'Callaghan:
> Signed-off-by: Edward O'Callaghan <funfunctor at folklore1984.net>
> ---
>   drivers/gpu/drm/amd/amdkfd/cik_event_interrupt.c | 15 +++++----------
>   drivers/gpu/drm/amd/amdkfd/cik_int.h             | 20 ++++++++++++++++----
>   2 files changed, 21 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdkfd/cik_event_interrupt.c b/drivers/gpu/drm/amd/amdkfd/cik_event_interrupt.c
> index 211fc48..1c47b9e 100644
> --- a/drivers/gpu/drm/amd/amdkfd/cik_event_interrupt.c
> +++ b/drivers/gpu/drm/amd/amdkfd/cik_event_interrupt.c
> @@ -27,14 +27,12 @@
>   static bool cik_event_interrupt_isr(struct kfd_dev *dev,
>   					const uint32_t *ih_ring_entry)
>   {
> -	unsigned int pasid;
>   	const struct cik_ih_ring_entry *ihre =
>   			(const struct cik_ih_ring_entry *)ih_ring_entry;
>   
> -	pasid = (ihre->ring_id & 0xffff0000) >> 16;
>   
>   	/* Do not process in ISR, just request it to be forwarded to WQ. */
> -	return (pasid != 0) &&
> +	return (ihre->pasid != 0) &&
>   		(ihre->source_id == CIK_INTSRC_CP_END_OF_PIPE ||
>   		ihre->source_id == CIK_INTSRC_SQ_INTERRUPT_MSG ||
>   		ihre->source_id == CIK_INTSRC_CP_BAD_OPCODE);
> @@ -43,21 +41,18 @@ static bool cik_event_interrupt_isr(struct kfd_dev *dev,
>   static void cik_event_interrupt_wq(struct kfd_dev *dev,
>   					const uint32_t *ih_ring_entry)
>   {
> -	unsigned int pasid;
>   	const struct cik_ih_ring_entry *ihre =
>   			(const struct cik_ih_ring_entry *)ih_ring_entry;
>   
> -	pasid = (ihre->ring_id & 0xffff0000) >> 16;
> -
> -	if (pasid == 0)
> +	if (ihre->pasid == 0)
>   		return;
>   
>   	if (ihre->source_id == CIK_INTSRC_CP_END_OF_PIPE)
> -		kfd_signal_event_interrupt(pasid, 0, 0);
> +		kfd_signal_event_interrupt(ihre->pasid, 0, 0);
>   	else if (ihre->source_id == CIK_INTSRC_SQ_INTERRUPT_MSG)
> -		kfd_signal_event_interrupt(pasid, ihre->data & 0xFF, 8);
> +		kfd_signal_event_interrupt(ihre->pasid, ihre->data & 0xFF, 8);
>   	else if (ihre->source_id == CIK_INTSRC_CP_BAD_OPCODE)
> -		kfd_signal_hw_exception_event(pasid);
> +		kfd_signal_hw_exception_event(ihre->pasid);
>   }
>   
>   const struct kfd_event_interrupt_class event_interrupt_class_cik = {
> diff --git a/drivers/gpu/drm/amd/amdkfd/cik_int.h b/drivers/gpu/drm/amd/amdkfd/cik_int.h
> index 79a16d2..27d1ede 100644
> --- a/drivers/gpu/drm/amd/amdkfd/cik_int.h
> +++ b/drivers/gpu/drm/amd/amdkfd/cik_int.h
> @@ -26,10 +26,22 @@
>   #include <linux/types.h>
>   
>   struct cik_ih_ring_entry {
> -	uint32_t source_id;
> -	uint32_t data;
> -	uint32_t ring_id;
> -	uint32_t reserved;
> +	uint32_t source_id:8;
> +	uint32_t reserved1:8;
> +	uint32_t reserved2:16;
> +
> +	uint32_t data:28;
> +	uint32_t reserved3:4;
> +
> +	/* pipeid, meid and unused3 are officially called RINGID,
> +	 * but for our purposes, they always decode into pipe and ME. */
> +	uint32_t pipeid:2;
> +	uint32_t meid:2;
> +	uint32_t reserved4:4;
> +	uint32_t vmid:8;
> +	uint32_t pasid:16;
> +
> +	uint32_t reserved5;
>   };
>   
>   #define CIK_INTSRC_DEQUEUE_COMPLETE	0xC6