Re: [PATCH 07/43] drm/xe: Add xe_device backpointer to xe_mmio

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

On 04.09.2024 02:21, Matt Roper wrote:
> Once MMIO operations stop being (incorrectly) tied to a GT, we'll still
> need a device backpointer for feature checks, message logging, and
> tracepoints.
> 
> Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
> ---
>  drivers/gpu/drm/xe/xe_device_types.h | 3 +++
>  drivers/gpu/drm/xe/xe_mmio.c         | 3 +++
>  drivers/gpu/drm/xe/xe_pci.c          | 2 ++
>  3 files changed, 8 insertions(+)
> 
> diff --git a/drivers/gpu/drm/xe/xe_device_types.h b/drivers/gpu/drm/xe/xe_device_types.h
> index 75490753feda..19c21e55e153 100644
> --- a/drivers/gpu/drm/xe/xe_device_types.h
> +++ b/drivers/gpu/drm/xe/xe_device_types.h
> @@ -115,6 +115,9 @@ struct xe_mem_region {
>   * subregions of the overall IO space).
>   */
>  struct xe_mmio {
> +	/** @xe: Backpointer to Xe device, used for tracing */
> +	struct xe_device *xe;

since all MMIO register regions are still more/less tile-based, then
maybe it would be better to have backpointer to the xe_tile, where this
MMIO region belongs, rather than xe_device?

we can always use tile->xe if needed

> +
>  	/** @regs: Map used to access registers. */
>  	void __iomem *regs;
>  
> diff --git a/drivers/gpu/drm/xe/xe_mmio.c b/drivers/gpu/drm/xe/xe_mmio.c
> index 4c7215ed3954..dd2076b9003e 100644
> --- a/drivers/gpu/drm/xe/xe_mmio.c
> +++ b/drivers/gpu/drm/xe/xe_mmio.c
> @@ -98,6 +98,7 @@ static void mmio_multi_tile_setup(struct xe_device *xe, size_t tile_mmio_size)
>  	for_each_tile(tile, xe, id) {
>  		tile->mmio.regs_length = SZ_4M;
>  		tile->mmio.regs = regs;
> +		tile->mmio.xe = xe;
>  		regs += tile_mmio_size;
>  	}
>  }
> @@ -134,6 +135,7 @@ static void mmio_extension_setup(struct xe_device *xe, size_t tile_mmio_size,
>  	for_each_tile(tile, xe, id) {
>  		tile->mmio_ext.regs_length = tile_mmio_ext_size;
>  		tile->mmio_ext.regs = regs;
> +		tile->mmio_ext.xe = xe;
>  		regs += tile_mmio_ext_size;
>  	}
>  }
> @@ -180,6 +182,7 @@ int xe_mmio_init(struct xe_device *xe)
>  	/* Setup first tile; other tiles (if present) will be setup later. */
>  	root_tile->mmio.regs_length = SZ_4M;
>  	root_tile->mmio.regs = xe->mmio.regs;
> +	root_tile->mmio.xe = xe;
>  
>  	return devm_add_action_or_reset(xe->drm.dev, mmio_fini, xe);
>  }
> diff --git a/drivers/gpu/drm/xe/xe_pci.c b/drivers/gpu/drm/xe/xe_pci.c
> index 5b09a1cbd821..e222539022d5 100644
> --- a/drivers/gpu/drm/xe/xe_pci.c
> +++ b/drivers/gpu/drm/xe/xe_pci.c
> @@ -714,6 +714,7 @@ static int xe_info_init(struct xe_device *xe,
>  		gt->info.engine_mask = graphics_desc->hw_engine_mask;
>  		gt->mmio.regs = tile->mmio.regs;
>  		gt->mmio.regs_length = tile->mmio.regs_length;
> +		gt->mmio.xe = xe;
>  		if (MEDIA_VER(xe) < 13 && media_desc)
>  			gt->info.engine_mask |= media_desc->hw_engine_mask;
>  
> @@ -736,6 +737,7 @@ static int xe_info_init(struct xe_device *xe,
>  		gt->mmio.regs_length = tile->mmio.regs_length;
>  		gt->mmio.adj_offset = MEDIA_GT_GSI_OFFSET;
>  		gt->mmio.adj_limit = MEDIA_GT_GSI_LENGTH;
> +		gt->mmio.xe = xe;
>  
>  		/*
>  		 * FIXME: At the moment multi-tile and standalone media are