[Intel-gfx] [PATCH 3/8] drm/i915/guc: Extend the GEN9 WOPCM HW restrictions to early CNL

[Daniele Ceraolo Spurio]

On 23/03/18 05:34, Michał Winiarski wrote:
> We imposed additional restrictions to GEN9 WOPCM partitioning. However,
> we ignored early steppings of CNL, to which those restrictions also
> apply. Let's also tweak the logic a bit by having separate helpers for
> returning extra size needed for the restriction to be satisfied, and
> handle the results in the caller.
> 
> References: 6b0478fb722a ("drm/i915: Implement dynamic GuC WOPCM offset and size calculation")
> Signed-off-by: Michał Winiarski <michal.winiarski at intel.com>
> Cc: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Jackie Li <yaodong.li at intel.com>
> Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
> Cc: Michal Wajdeczko <michal.wajdeczko at intel.com>
> ---
>   drivers/gpu/drm/i915/intel_wopcm.c | 63 ++++++++++++++++++++++----------------
>   1 file changed, 37 insertions(+), 26 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_wopcm.c b/drivers/gpu/drm/i915/intel_wopcm.c
> index 42876f8890e7..50854a6b9493 100644
> --- a/drivers/gpu/drm/i915/intel_wopcm.c
> +++ b/drivers/gpu/drm/i915/intel_wopcm.c
> @@ -84,58 +84,69 @@ static inline u32 context_reserved_size(struct drm_i915_private *i915)
>   		return 0;
>   }
>   
> -static inline int gen9_check_dword_gap(u32 guc_wopcm_base, u32 guc_wopcm_size)
> +static u32
> +gen9_size_for_dword_gap_restriction(u32 guc_wopcm_base, u32 guc_wopcm_size)
>   {
> -	u32 offset;
> +	s32 additional_size;
>   
>   	/*
>   	 * GuC WOPCM size shall be at least a dword larger than the offset from
>   	 * WOPCM base (GuC WOPCM offset from WOPCM base + GEN9_GUC_WOPCM_OFFSET)
>   	 * due to hardware limitation on Gen9.
>   	 */
> -	offset = guc_wopcm_base + GEN9_GUC_WOPCM_OFFSET;
> -	if (offset > guc_wopcm_size ||
> -	    (guc_wopcm_size - offset) < sizeof(u32)) {
> -		DRM_ERROR("GuC WOPCM size %uKiB is too small. %uKiB needed.\n",
> -			  guc_wopcm_size / 1024,
> -			  (u32)(offset + sizeof(u32)) / 1024);
> -		return -E2BIG;
> -	}
> +	additional_size = guc_wopcm_base + GEN9_GUC_WOPCM_OFFSET +

GUC_FW_RESERVED is 256k for CNL (Bspec: 1184) so we need a 
GEN10_GUC_WOPCM_OFFSET.

Daniele

> +			  sizeof(u32) - guc_wopcm_size;
>   
> -	return 0;
> +	if (additional_size <= 0)
> +		return 0;
> +
> +	return additional_size;
>   }
>   
> -static inline int gen9_check_huc_fw_fits(u32 guc_wopcm_size, u32 huc_fw_size)
> +static u32
> +gen9_size_for_huc_restriction(u32 guc_wopcm_size, u32 huc_fw_size)
>   {
> +	s32 additional_size;
> +
>   	/*
>   	 * On Gen9 & CNL A0, hardware requires the total available GuC WOPCM
>   	 * size to be larger than or equal to HuC firmware size. Otherwise,
>   	 * firmware uploading would fail.
>   	 */
> -	if (huc_fw_size > guc_wopcm_size - GUC_WOPCM_RESERVED) {
> -		DRM_ERROR("HuC FW (%uKiB) won't fit in GuC WOPCM (%uKiB).\n",
> -			  huc_fw_size / 1024,
> -			  (guc_wopcm_size - GUC_WOPCM_RESERVED) / 1024);
> -		return -E2BIG;
> -	}
> +	additional_size = huc_fw_size - (guc_wopcm_size - GUC_WOPCM_RESERVED);
>   
> -	return 0;
> +	if (additional_size <= 0)
> +		return 0;
> +
> +	return additional_size;
>   }
>   
>   static inline int check_hw_restriction(struct drm_i915_private *i915,
>   				       u32 guc_wopcm_base, u32 guc_wopcm_size,
>   				       u32 huc_fw_size)
>   {
> -	int err = 0;
> +	u32 size;
> +
> +	if (IS_GEN9(i915) || IS_CNL_REVID(i915, CNL_REVID_A0, CNL_REVID_A0)) {
> +		size = gen9_size_for_dword_gap_restriction(guc_wopcm_base,
> +							   guc_wopcm_size);
> +		if (size)
> +			goto err;
> +
> +		size = gen9_size_for_huc_restriction(guc_wopcm_size,
> +						     huc_fw_size);
> +		if (size)
> +			goto err;
> +	}
>   
> -	if (IS_GEN9(i915))
> -		err = gen9_check_dword_gap(guc_wopcm_base, guc_wopcm_size);
> +	return 0;
>   
> -	if (!err &&
> -	    (IS_GEN9(i915) || IS_CNL_REVID(i915, CNL_REVID_A0, CNL_REVID_A0)))
> -		err = gen9_check_huc_fw_fits(guc_wopcm_size, huc_fw_size);
> +err:
> +	DRM_ERROR("GuC WOPCM size %uKiB is too small. %uKiB more needed.\n",
> +		  guc_wopcm_size / 1024,
> +		  size / 1024);
>   
> -	return err;
> +	return -E2BIG;
>   }
>   
>   /**
>