[Intel-xe] [PATCH 5/9] drm/xe: Use vfunc to initialize PAT

Matt Roper matthew.d.roper at intel.com
Mon Sep 25 23:08:21 UTC 2023


On Mon, Sep 25, 2023 at 03:10:45PM -0700, Lucas De Marchi wrote:
> Split the PAT initialization between SW-only and HW. The _early() only
> sets up the ops and data structure that are used later to program the
> tables. This allows the PAT to be easily extended to other platforms.
> 
> Signed-off-by: Lucas De Marchi <lucas.demarchi at intel.com>
> ---
>  drivers/gpu/drm/xe/xe_device.c       |  3 ++
>  drivers/gpu/drm/xe/xe_device_types.h | 13 ++++++
>  drivers/gpu/drm/xe/xe_pat.c          | 59 +++++++++++++++++++++-------
>  drivers/gpu/drm/xe/xe_pat.h          | 11 ++++++
>  4 files changed, 72 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_device.c b/drivers/gpu/drm/xe/xe_device.c
> index 687dc3d79a66..046b7a087451 100644
> --- a/drivers/gpu/drm/xe/xe_device.c
> +++ b/drivers/gpu/drm/xe/xe_device.c
> @@ -26,6 +26,7 @@
>  #include "xe_irq.h"
>  #include "xe_mmio.h"
>  #include "xe_module.h"
> +#include "xe_pat.h"
>  #include "xe_pcode.h"
>  #include "xe_pm.h"
>  #include "xe_query.h"
> @@ -276,6 +277,8 @@ int xe_device_probe(struct xe_device *xe)
>  	int err;
>  	u8 id;
>  
> +	xe_pat_init_early(xe);
> +
>  	xe->info.mem_region_mask = 1;
>  	err = xe_display_init_nommio(xe);
>  	if (err)
> diff --git a/drivers/gpu/drm/xe/xe_device_types.h b/drivers/gpu/drm/xe/xe_device_types.h
> index 32ab0fea04ee..98835ee058f5 100644
> --- a/drivers/gpu/drm/xe/xe_device_types.h
> +++ b/drivers/gpu/drm/xe/xe_device_types.h
> @@ -25,6 +25,7 @@
>  #endif
>  
>  struct xe_ggtt;
> +struct xe_pat_ops;
>  
>  #define XE_BO_INVALID_OFFSET	LONG_MAX
>  
> @@ -331,6 +332,18 @@ struct xe_device {
>  		atomic_t ref;
>  	} mem_access;
>  
> +	/**
> +	 * @pat: Encapsulate PAT related stuff
> +	 */
> +	struct {
> +		/** Internal operations to abstract platforms */
> +		const struct xe_pat_ops *ops;

We can start with this for now, but down the road we may want to move
this into xe_gt instead of keeping it in the xe_device.  Moving it to
xe_gt would let us just have a single 'program' vfunc, but would also
make it easier to provide per-GT functionality for other things like
coherency decisions.  Even though the coherency is marked in the
device-wide table and is theoretically equivalent for each GT, we've
already seen workarounds like Wa_22016122933 that alter the true
coherency behavior and require that we select actual PAT indices in a
different manner on each GT.

Reviewed-by: Matt Roper <matthew.d.roper at intel.com>


Matt

> +		/** PAT table to program in the HW */
> +		const u32 *table;
> +		/** Number of PAT entries */
> +		int n_entries;
> +	} pat;
> +
>  	/** @d3cold: Encapsulate d3cold related stuff */
>  	struct {
>  		/** capable: Indicates if root port is d3cold capable */
> diff --git a/drivers/gpu/drm/xe/xe_pat.c b/drivers/gpu/drm/xe/xe_pat.c
> index 71e0e047fff3..86386633e206 100644
> --- a/drivers/gpu/drm/xe/xe_pat.c
> +++ b/drivers/gpu/drm/xe/xe_pat.c
> @@ -32,6 +32,11 @@
>  #define TGL_PAT_WC				REG_FIELD_PREP(TGL_MEM_TYPE_MASK, 1)
>  #define TGL_PAT_UC				REG_FIELD_PREP(TGL_MEM_TYPE_MASK, 0)
>  
> +struct xe_pat_ops {
> +	void (*program_graphics)(struct xe_gt *gt, const u32 table[], int n_entries);
> +	void (*program_media)(struct xe_gt *gt, const u32 table[], int n_entries);
> +};
> +
>  static const u32 tgl_pat_table[] = {
>  	[0] = TGL_PAT_WB,
>  	[1] = TGL_PAT_WC,
> @@ -80,24 +85,37 @@ static void program_pat_mcr(struct xe_gt *gt, const u32 table[], int n_entries)
>  	}
>  }
>  
> -void xe_pat_init(struct xe_gt *gt)
> -{
> -	struct xe_device *xe = gt_to_xe(gt);
> +static const struct xe_pat_ops tgl_pat_ops = {
> +	.program_graphics = program_pat,
> +};
> +
> +static const struct xe_pat_ops pvc_pat_ops = {
> +	.program_graphics = program_pat_mcr,
> +};
> +
> +/*
> + * SAMedia register offsets are adjusted by the write methods and they target
> + * registers that are not MCR, while for normal GT they are MCR
> + */
> +static const struct xe_pat_ops mtl_pat_ops = {
> +	.program_graphics = program_pat,
> +	.program_media = program_pat_mcr,
> +};
>  
> +void xe_pat_init_early(struct xe_device *xe)
> +{
>  	if (xe->info.platform == XE_METEORLAKE) {
> -		/*
> -		 * SAMedia register offsets are adjusted by the write methods
> -		 * and they target registers that are not MCR, while for normal
> -		 * GT they are MCR
> -		 */
> -		if (xe_gt_is_media_type(gt))
> -			program_pat(gt, mtl_pat_table, ARRAY_SIZE(mtl_pat_table));
> -		else
> -			program_pat_mcr(gt, mtl_pat_table, ARRAY_SIZE(mtl_pat_table));
> +		xe->pat.ops = &mtl_pat_ops;
> +		xe->pat.table = mtl_pat_table;
> +		xe->pat.n_entries = ARRAY_SIZE(mtl_pat_table);
>  	} else if (xe->info.platform == XE_PVC || xe->info.platform == XE_DG2) {
> -		program_pat_mcr(gt, pvc_pat_table, ARRAY_SIZE(pvc_pat_table));
> +		xe->pat.ops = &pvc_pat_ops;
> +		xe->pat.table = pvc_pat_table;
> +		xe->pat.n_entries = ARRAY_SIZE(pvc_pat_table);
>  	} else if (GRAPHICS_VERx100(xe) <= 1210) {
> -		program_pat(gt, tgl_pat_table, ARRAY_SIZE(tgl_pat_table));
> +		xe->pat.ops = &tgl_pat_ops;
> +		xe->pat.table = tgl_pat_table;
> +		xe->pat.n_entries = ARRAY_SIZE(tgl_pat_table);
>  	} else {
>  		/*
>  		 * Going forward we expect to need new PAT settings for most
> @@ -111,3 +129,16 @@ void xe_pat_init(struct xe_gt *gt)
>  			GRAPHICS_VER(xe), GRAPHICS_VERx100(xe) % 100);
>  	}
>  }
> +
> +void xe_pat_init(struct xe_gt *gt)
> +{
> +	struct xe_device *xe = gt_to_xe(gt);
> +
> +	if (!xe->pat.ops)
> +		return;
> +
> +	if (xe_gt_is_media_type(gt))
> +		xe->pat.ops->program_media(gt, xe->pat.table, xe->pat.n_entries);
> +	else
> +		xe->pat.ops->program_graphics(gt, xe->pat.table, xe->pat.n_entries);
> +}
> diff --git a/drivers/gpu/drm/xe/xe_pat.h b/drivers/gpu/drm/xe/xe_pat.h
> index 659de4008131..744318cab69b 100644
> --- a/drivers/gpu/drm/xe/xe_pat.h
> +++ b/drivers/gpu/drm/xe/xe_pat.h
> @@ -7,7 +7,18 @@
>  #define _XE_PAT_H_
>  
>  struct xe_gt;
> +struct xe_device;
>  
> +/**
> + * xe_pat_init_early - SW initialization, setting up data based on device
> + * @xe: xe device
> + */
> +void xe_pat_init_early(struct xe_device *xe);
> +
> +/**
> + * xe_pat_init_early - Program HW PAT table
> + * @gt: GT structure
> + */
>  void xe_pat_init(struct xe_gt *gt);
>  
>  #endif
> -- 
> 2.40.1
> 

-- 
Matt Roper
Graphics Software Engineer
Linux GPU Platform Enablement
Intel Corporation


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