Re: [PATCH v8 5/7] drm/xe/eustall: Add EU stall sampling support for Xe2

["Dixit, Ashutosh" <ashutosh.dixit@intel.com>]

On Wed, 15 Jan 2025 12:02:11 -0800, Harish Chegondi wrote:
> diff --git a/drivers/gpu/drm/xe/xe_eu_stall.c b/drivers/gpu/drm/xe/xe_eu_stall.c
> index 437782f8433c..d72f80a9dfe4 100644
> --- a/drivers/gpu/drm/xe/xe_eu_stall.c
> +++ b/drivers/gpu/drm/xe/xe_eu_stall.c
> @@ -73,6 +73,42 @@ struct xe_eu_stall_data_pvc {
>	__u64 unused[6];
>  } __packed;
>
> +/**
> + * struct xe_eu_stall_data_xe2 - EU stall data format for LNL, BMG
> + *
> + * Bits		Field
> + * 0  to 28	IP (addr)
> + * 29 to 36	Tdr count
> + * 37 to 44	other count
> + * 45 to 52	control count
> + * 53 to 60	pipestall count
> + * 61 to 68	send count
> + * 69 to 76	dist_acc count
> + * 77 to 84	sbid count
> + * 85 to 92	sync count
> + * 93 to 100	inst_fetch count
> + * 101 to 108	Active count
> + * 109 to 111	Exid
> + * 112		EndFlag (is always 1)
> + */
> +struct xe_eu_stall_data_xe2 {
> +	__u64 ip_addr:29;
> +	__u64 tdr_count:8;
> +	__u64 other_count:8;
> +	__u64 control_count:8;
> +	__u64 pipestall_count:8;
> +	__u64 send_count:8;
> +	__u64 dist_acc_count:8;
> +	__u64 sbid_count:8;
> +	__u64 sync_count:8;
> +	__u64 inst_fetch_count:8;
> +	__u64 active_count:8;
> +	__u64 ex_id:3;
> +	__u64 end_flag:1;
> +	__u64 unused_bits:15;
> +	__u64 unused[6];
> +} __packed;

Same question about whether or not to retain this struct. Retain it if we
want to document this information otherwise drop it and just keep sizeof.

> +
>  static u64 per_xecore_buf_size = SZ_512K;
>
>  static unsigned long
> @@ -83,6 +119,8 @@ xe_eu_stall_data_record_size(struct xe_device *xe)
>
>	if (platform == XE_PVC)
>		record_size = sizeof(struct xe_eu_stall_data_pvc);
> +	else if ((platform == XE_LUNARLAKE) || (platform == XE_BATTLEMAGE))

'else if (GRAPHICS_VER(xe) >= 20)' so that we don't have to keep adding
each individual platform.

> +		record_size = sizeof(struct xe_eu_stall_data_xe2);
>
>	return record_size;
>  }
> @@ -311,10 +349,16 @@ eu_stall_data_buf_check(struct xe_eu_stall_data_stream *stream)
>  static void
>  clear_dropped_eviction_line_bit(struct xe_gt *gt, u16 group, u16 instance)
>  {
> +	struct xe_device *xe = gt_to_xe(gt);
>	u32 write_ptr_reg;
>
> -	/* On PVC, the overflow bit has to be cleared by writing 1 to it. */
> -	write_ptr_reg = _MASKED_BIT_ENABLE(XEHPC_EUSTALL_REPORT_OVERFLOW_DROP);
> +	/* On PVC, the overflow bit has to be cleared by writing 1 to it.
> +	 * On other GPUs, the bit has to be cleared by writing 0 to it.
> +	 */
> +	if (GRAPHICS_VER(xe) >= 20)
> +		write_ptr_reg = _MASKED_BIT_DISABLE(XEHPC_EUSTALL_REPORT_OVERFLOW_DROP);
> +	else
> +		write_ptr_reg = _MASKED_BIT_ENABLE(XEHPC_EUSTALL_REPORT_OVERFLOW_DROP);
>
>	xe_gt_mcr_unicast_write(gt, XEHPC_EUSTALL_REPORT, write_ptr_reg, group, instance);
>  }
> @@ -882,7 +926,9 @@ static const struct file_operations fops_eu_stall = {
>
>  static inline bool has_eu_stall_sampling_support(struct xe_device *xe)
>  {
> -	return ((xe->info.platform == XE_PVC) ? true : false);
> +	return ((xe->info.platform == XE_PVC ||
> +		 xe->info.platform == XE_LUNARLAKE ||
> +		 xe->info.platform == XE_BATTLEMAGE) ? true : false);

Same here, use (GRAPHICS_VER(xe) >= 20).

>  }
>
>  /**
> --
> 2.47.1
>