Re: [PATCH v8 22/33] drm/xe: Add CTB_H2G_BUFFER_OFFSET define

[Michal Wajdeczko <michal.wajdeczko@intel.com>]

On 10/7/2025 3:04 PM, Matthew Brost wrote:
> Rather than open coding the H2G buffer offset as 'CTB_DESC_SIZE * 2' add
> CTB_H2G_BUFFER_OFFSET define.
> 
> Signed-off-by: Matthew Brost <matthew.brost@intel.com>
> ---
>  drivers/gpu/drm/xe/xe_guc_ct.c | 11 ++++++-----
>  1 file changed, 6 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_guc_ct.c b/drivers/gpu/drm/xe/xe_guc_ct.c
> index fd2385635962..503cf5cb5d33 100644
> --- a/drivers/gpu/drm/xe/xe_guc_ct.c
> +++ b/drivers/gpu/drm/xe/xe_guc_ct.c
> @@ -167,6 +167,7 @@ ct_to_xe(struct xe_guc_ct *ct)
>   */
>  
>  #define CTB_DESC_SIZE		ALIGN(sizeof(struct guc_ct_buffer_desc), SZ_2K)
> +#define CTB_H2G_BUFFER_OFFSET	(CTB_DESC_SIZE * 2)
>  #define CTB_H2G_BUFFER_SIZE	(SZ_4K)
>  #define CTB_G2H_BUFFER_SIZE	(SZ_128K)

maybe one day for completeness we should add remaining OFFSET macros

>  #define G2H_ROOM_BUFFER_SIZE	(CTB_G2H_BUFFER_SIZE / 2)
> @@ -190,7 +191,7 @@ long xe_guc_ct_queue_proc_time_jiffies(struct xe_guc_ct *ct)
>  
>  static size_t guc_ct_size(void)
>  {
> -	return 2 * CTB_DESC_SIZE + CTB_H2G_BUFFER_SIZE +
> +	return CTB_H2G_BUFFER_OFFSET + CTB_H2G_BUFFER_SIZE +
>  		CTB_G2H_BUFFER_SIZE;

and convert this helper function to macro too

>  }
>  
> @@ -331,7 +332,7 @@ static void guc_ct_ctb_h2g_init(struct xe_device *xe, struct guc_ctb *h2g,
>  	h2g->desc = *map;
>  	xe_map_memset(xe, &h2g->desc, 0, 0, sizeof(struct guc_ct_buffer_desc));
>  
> -	h2g->cmds = IOSYS_MAP_INIT_OFFSET(map, CTB_DESC_SIZE * 2);
> +	h2g->cmds = IOSYS_MAP_INIT_OFFSET(map, CTB_H2G_BUFFER_OFFSET);
>  }
>  
>  static void guc_ct_ctb_g2h_init(struct xe_device *xe, struct guc_ctb *g2h,
> @@ -349,7 +350,7 @@ static void guc_ct_ctb_g2h_init(struct xe_device *xe, struct guc_ctb *g2h,
>  	g2h->desc = IOSYS_MAP_INIT_OFFSET(map, CTB_DESC_SIZE);
>  	xe_map_memset(xe, &g2h->desc, 0, 0, sizeof(struct guc_ct_buffer_desc));
>  
> -	g2h->cmds = IOSYS_MAP_INIT_OFFSET(map, CTB_DESC_SIZE * 2 +
> +	g2h->cmds = IOSYS_MAP_INIT_OFFSET(map, CTB_H2G_BUFFER_OFFSET +
>  					    CTB_H2G_BUFFER_SIZE);
>  }
>  
> @@ -360,7 +361,7 @@ static int guc_ct_ctb_h2g_register(struct xe_guc_ct *ct)
>  	int err;
>  
>  	desc_addr = xe_bo_ggtt_addr(ct->bo);
> -	ctb_addr = xe_bo_ggtt_addr(ct->bo) + CTB_DESC_SIZE * 2;
> +	ctb_addr = xe_bo_ggtt_addr(ct->bo) + CTB_H2G_BUFFER_OFFSET;
>  	size = ct->ctbs.h2g.info.size * sizeof(u32);
>  
>  	err = xe_guc_self_cfg64(guc,
> @@ -387,7 +388,7 @@ static int guc_ct_ctb_g2h_register(struct xe_guc_ct *ct)
>  	int err;
>  
>  	desc_addr = xe_bo_ggtt_addr(ct->bo) + CTB_DESC_SIZE;
> -	ctb_addr = xe_bo_ggtt_addr(ct->bo) + CTB_DESC_SIZE * 2 +
> +	ctb_addr = xe_bo_ggtt_addr(ct->bo) + CTB_H2G_BUFFER_OFFSET +
>  		CTB_H2G_BUFFER_SIZE;
>  	size = ct->ctbs.g2h.info.size * sizeof(u32);
>  

but still looks good, so

Reviewed-by: Michal Wajdeczko <michal.wajdeczko@intel.com>