Re: [PATCH 1/2] drm/xe: Pack fault type and level into a u8

[Francois Dugast <francois.dugast@intel.com>]

On Thu, Feb 12, 2026 at 12:42:26PM -0800, Matthew Brost wrote:
> Pack the fault type and level fields into a single u8 to save space in
> struct xe_pagefault. This also makes future extensions easier.
> 
> Signed-off-by: Matthew Brost <matthew.brost@intel.com>

Both page fault level and type reported by GuC fit in their new masks
according to bspec, might be worth adding a reference to it in the
commit message: 59654.

Reviewed-by: Francois Dugast <francois.dugast@intel.com>

> ---
>  drivers/gpu/drm/xe/xe_guc_pagefault.c   |  9 ++++++---
>  drivers/gpu/drm/xe/xe_pagefault.c       | 12 +++++++-----
>  drivers/gpu/drm/xe/xe_pagefault_types.h | 14 +++++++-------
>  3 files changed, 20 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_guc_pagefault.c b/drivers/gpu/drm/xe/xe_guc_pagefault.c
> index 719a18187a31..1166b0a5fa21 100644
> --- a/drivers/gpu/drm/xe/xe_guc_pagefault.c
> +++ b/drivers/gpu/drm/xe/xe_guc_pagefault.c
> @@ -76,11 +76,14 @@ int xe_guc_pagefault_handler(struct xe_guc *guc, u32 *msg, u32 len)
>  		 PFD_VIRTUAL_ADDR_LO_SHIFT);
>  	pf.consumer.asid = FIELD_GET(PFD_ASID, msg[1]);
>  	pf.consumer.access_type = FIELD_GET(PFD_ACCESS_TYPE, msg[2]);
> -	pf.consumer.fault_type = FIELD_GET(PFD_FAULT_TYPE, msg[2]);
>  	if (FIELD_GET(XE2_PFD_TRVA_FAULT, msg[0]))
> -		pf.consumer.fault_level = XE_PAGEFAULT_LEVEL_NACK;
> +		pf.consumer.fault_type_level = XE_PAGEFAULT_TYPE_LEVEL_NACK;
>  	else
> -		pf.consumer.fault_level = FIELD_GET(PFD_FAULT_LEVEL, msg[0]);
> +		pf.consumer.fault_type_level =
> +			FIELD_PREP(XE_PAGEFAULT_LEVEL_MASK,
> +				   FIELD_GET(PFD_FAULT_LEVEL, msg[0])) |
> +			FIELD_PREP(XE_PAGEFAULT_TYPE_MASK,
> +				   FIELD_GET(PFD_FAULT_TYPE, msg[2]));
>  	pf.consumer.engine_class = FIELD_GET(PFD_ENG_CLASS, msg[0]);
>  	pf.consumer.engine_instance = FIELD_GET(PFD_ENG_INSTANCE, msg[0]);
>  
> diff --git a/drivers/gpu/drm/xe/xe_pagefault.c b/drivers/gpu/drm/xe/xe_pagefault.c
> index 6bee53d6ffc3..72f589fd2b64 100644
> --- a/drivers/gpu/drm/xe/xe_pagefault.c
> +++ b/drivers/gpu/drm/xe/xe_pagefault.c
> @@ -164,7 +164,7 @@ static int xe_pagefault_service(struct xe_pagefault *pf)
>  	bool atomic;
>  
>  	/* Producer flagged this fault to be nacked */
> -	if (pf->consumer.fault_level == XE_PAGEFAULT_LEVEL_NACK)
> +	if (pf->consumer.fault_type_level == XE_PAGEFAULT_TYPE_LEVEL_NACK)
>  		return -EFAULT;
>  
>  	vm = xe_pagefault_asid_to_vm(xe, pf->consumer.asid);
> @@ -225,17 +225,19 @@ static void xe_pagefault_print(struct xe_pagefault *pf)
>  {
>  	xe_gt_info(pf->gt, "\n\tASID: %d\n"
>  		   "\tFaulted Address: 0x%08x%08x\n"
> -		   "\tFaultType: %d\n"
> +		   "\tFaultType: %lu\n"
>  		   "\tAccessType: %d\n"
> -		   "\tFaultLevel: %d\n"
> +		   "\tFaultLevel: %lu\n"
>  		   "\tEngineClass: %d %s\n"
>  		   "\tEngineInstance: %d\n",
>  		   pf->consumer.asid,
>  		   upper_32_bits(pf->consumer.page_addr),
>  		   lower_32_bits(pf->consumer.page_addr),
> -		   pf->consumer.fault_type,
> +		   FIELD_GET(XE_PAGEFAULT_TYPE_MASK,
> +			     pf->consumer.fault_type_level),
>  		   pf->consumer.access_type,
> -		   pf->consumer.fault_level,
> +		   FIELD_GET(XE_PAGEFAULT_LEVEL_MASK,
> +			     pf->consumer.fault_type_level),
>  		   pf->consumer.engine_class,
>  		   xe_hw_engine_class_to_str(pf->consumer.engine_class),
>  		   pf->consumer.engine_instance);
> diff --git a/drivers/gpu/drm/xe/xe_pagefault_types.h b/drivers/gpu/drm/xe/xe_pagefault_types.h
> index d3b516407d60..0e378f41ede6 100644
> --- a/drivers/gpu/drm/xe/xe_pagefault_types.h
> +++ b/drivers/gpu/drm/xe/xe_pagefault_types.h
> @@ -73,19 +73,19 @@ struct xe_pagefault {
>  		 */
>  		u8 access_type;
>  		/**
> -		 * @consumer.fault_type: fault type, u8 rather than enum to
> -		 * keep size compact
> +		 * @consumer.fault_type_level: fault type and level, u8 rather
> +		 * than enum to keep size compact
>  		 */
> -		u8 fault_type;
> -#define XE_PAGEFAULT_LEVEL_NACK		0xff	/* Producer indicates nack fault */
> -		/** @consumer.fault_level: fault level */
> -		u8 fault_level;
> +		u8 fault_type_level;
> +#define XE_PAGEFAULT_TYPE_LEVEL_NACK		0xff	/* Producer indicates nack fault */
> +#define XE_PAGEFAULT_LEVEL_MASK			GENMASK(3, 0)
> +#define XE_PAGEFAULT_TYPE_MASK			GENMASK(7, 4)
>  		/** @consumer.engine_class: engine class */
>  		u8 engine_class;
>  		/** @consumer.engine_instance: engine instance */
>  		u8 engine_instance;
>  		/** consumer.reserved: reserved bits for future expansion */
> -		u8 reserved[7];
> +		u64 reserved;
>  	} consumer;
>  	/**
>  	 * @producer: State for the producer (i.e., HW/FW interface). Populated
> -- 
> 2.34.1
>