Re: [PATCH v5 1/2] drm/xe/query: Define and use a constant for the number of masks

[Lucas De Marchi <lucas.demarchi@intel.com>]

On Mon, Mar 25, 2024 at 11:14:38AM +0000, Francois Dugast wrote:
>Replace a magic value by a constant with an explicit name to make clear
>what it stands for: the number of masks returned by the topology query.
>
>Suggested-by: Zhanjun Dong <zhanjun.dong@intel.com>
>Signed-off-by: Francois Dugast <francois.dugast@intel.com>
>---
> drivers/gpu/drm/xe/xe_query.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
>diff --git a/drivers/gpu/drm/xe/xe_query.c b/drivers/gpu/drm/xe/xe_query.c
>index df407d73e5f5..109a96212310 100644
>--- a/drivers/gpu/drm/xe/xe_query.c
>+++ b/drivers/gpu/drm/xe/xe_query.c
>@@ -23,6 +23,8 @@
> #include "xe_mmio.h"
> #include "xe_ttm_vram_mgr.h"
>
>+#define TOPO_NUMBER_OF_MASKS   (3)
>+
> static const u16 xe_to_user_engine_class[] = {
> 	[XE_ENGINE_CLASS_RENDER] = DRM_XE_ENGINE_CLASS_RENDER,
> 	[XE_ENGINE_CLASS_COPY] = DRM_XE_ENGINE_CLASS_COPY,
>@@ -454,7 +456,8 @@ static int query_hwconfig(struct xe_device *xe,
> static size_t calc_topo_query_size(struct xe_device *xe)
> {
> 	return xe->info.gt_count *
>-		(3 * sizeof(struct drm_xe_query_topology_mask) +
>+		(TOPO_NUMBER_OF_MASKS
>+		 * sizeof(struct drm_xe_query_topology_mask) +

actually no.... the number here should match the entries below

> 		 sizeof_field(struct xe_gt, fuse_topo.g_dss_mask) +
> 		 sizeof_field(struct xe_gt, fuse_topo.c_dss_mask) +
> 		 sizeof_field(struct xe_gt, fuse_topo.eu_mask_per_dss));

what do we gain moving it elsewhere? I think it should match the number
of types and hence maybe use same "namespace", but that also leads me to
another odd thing:  why is drm_xe_query_topology_mask.type handled like
a mask rather than an index?

+Matt Roper who implemented this originally afaics in commit
eaa6ccf582f5e3252aedea81559fcbf71ed9ccde.

Lucaas De Marchi


>-- 
>2.34.1
>