[Intel-gfx] [PATCH] drm/i915/stolen: Deduce base of reserved portion as top-size on vlv

Ville Syrjälä ville.syrjala at linux.intel.com
Mon Mar 12 15:46:35 UTC 2018


On Mon, Mar 12, 2018 at 03:29:13PM +0000, Chris Wilson wrote:
> On Valleyview, the HW deduces the base of the reserved portion of stolen
> memory as being (top - size) and the address field within
> GEN6_STOLEN_RESERVED is set to 0. Add yet another GEN6_STOLEN_RESERVED
> reader to cope with the subtly different path required for vlv.
> 
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> Cc: Imre Deak <imre.deak at intel.com>
> ---
> I left the suggestion to modify chv as we already have a custom function
> for Braswell and so far it appears to be happy. If it ain't broke...
> -Chris
> ---
>  drivers/gpu/drm/i915/i915_gem_stolen.c | 91 +++++++++++++++++++++++++++-------
>  1 file changed, 74 insertions(+), 17 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_gem_stolen.c b/drivers/gpu/drm/i915/i915_gem_stolen.c
> index b04e2551bae6..5c361a7c3b83 100644
> --- a/drivers/gpu/drm/i915/i915_gem_stolen.c
> +++ b/drivers/gpu/drm/i915/i915_gem_stolen.c
> @@ -174,13 +174,17 @@ void i915_gem_cleanup_stolen(struct drm_device *dev)
>  }
>  
>  static void g4x_get_stolen_reserved(struct drm_i915_private *dev_priv,
> -				    resource_size_t *base, resource_size_t *size)
> +				    resource_size_t *base,
> +				    resource_size_t *size)
>  {
> -	uint32_t reg_val = I915_READ(IS_GM45(dev_priv) ?
> -				     CTG_STOLEN_RESERVED :
> -				     ELK_STOLEN_RESERVED);
> +	u32 reg_val = I915_READ(IS_GM45(dev_priv) ?
> +				CTG_STOLEN_RESERVED :
> +				ELK_STOLEN_RESERVED);
>  	resource_size_t stolen_top = dev_priv->dsm.end + 1;
>  
> +	DRM_DEBUG_DRIVER("%s_STOLEN_RESERVED = %x\n",
> +			 IS_GM45(dev_priv) ? "CTG" : "ELK", reg_val);
> +
>  	if ((reg_val & G4X_STOLEN_RESERVED_ENABLE) == 0) {
>  		*base = 0;
>  		*size = 0;
> @@ -208,9 +212,12 @@ static void g4x_get_stolen_reserved(struct drm_i915_private *dev_priv,
>  }
>  
>  static void gen6_get_stolen_reserved(struct drm_i915_private *dev_priv,
> -				     resource_size_t *base, resource_size_t *size)
> +				     resource_size_t *base,
> +				     resource_size_t *size)
>  {
> -	uint32_t reg_val = I915_READ(GEN6_STOLEN_RESERVED);
> +	u32 reg_val = I915_READ(GEN6_STOLEN_RESERVED);
> +
> +	DRM_DEBUG_DRIVER("GEN6_STOLEN_RESERVED = %x\n", reg_val);
>  
>  	if ((reg_val & GEN6_STOLEN_RESERVED_ENABLE) == 0) {
>  		*base = 0;
> @@ -239,10 +246,46 @@ static void gen6_get_stolen_reserved(struct drm_i915_private *dev_priv,
>  	}
>  }
>  
> +static void vlv_get_stolen_reserved(struct drm_i915_private *dev_priv,
> +				    resource_size_t *base,
> +				    resource_size_t *size)
> +{
> +	u32 reg_val = I915_READ(GEN6_STOLEN_RESERVED);
> +
> +	DRM_DEBUG_DRIVER("GEN6_STOLEN_RESERVED = %x\n", reg_val);
> +
> +	if ((reg_val & GEN6_STOLEN_RESERVED_ENABLE) == 0) {
> +		*base = 0;
> +		*size = 0;
> +		return;
> +	}
> +
> +	switch (reg_val & GEN7_STOLEN_RESERVED_SIZE_MASK) {
> +	case GEN7_STOLEN_RESERVED_1M:
> +		*size = 1024 * 1024;
> +		break;
> +	case GEN7_STOLEN_RESERVED_256K:
> +		*size = 256 * 1024;
> +		break;

I believe 1MiB is the only legal size on VLV. So we might want to leave
out the 256KiB case here.

Either way
Reviewed-by: Ville Syrjälä <ville.syrjala at linux.intel.com>

> +	default:
> +		*size = 1024 * 1024;
> +		MISSING_CASE(reg_val & GEN7_STOLEN_RESERVED_SIZE_MASK);
> +	}
> +
> +	/*
> +	 * On vlv, the ADDR_MASK portion is left as 0 and HW deduces the
> +	 * reserved location as (top - size).
> +	 */
> +	*base = dev_priv->dsm.end + 1 - *size;
> +}
> +
>  static void gen7_get_stolen_reserved(struct drm_i915_private *dev_priv,
> -				     resource_size_t *base, resource_size_t *size)
> +				     resource_size_t *base,
> +				     resource_size_t *size)
>  {
> -	uint32_t reg_val = I915_READ(GEN6_STOLEN_RESERVED);
> +	u32 reg_val = I915_READ(GEN6_STOLEN_RESERVED);
> +
> +	DRM_DEBUG_DRIVER("GEN6_STOLEN_RESERVED = %x\n", reg_val);
>  
>  	if ((reg_val & GEN6_STOLEN_RESERVED_ENABLE) == 0) {
>  		*base = 0;
> @@ -266,9 +309,12 @@ static void gen7_get_stolen_reserved(struct drm_i915_private *dev_priv,
>  }
>  
>  static void chv_get_stolen_reserved(struct drm_i915_private *dev_priv,
> -				    resource_size_t *base, resource_size_t *size)
> +				    resource_size_t *base,
> +				    resource_size_t *size)
>  {
> -	uint32_t reg_val = I915_READ(GEN6_STOLEN_RESERVED);
> +	u32 reg_val = I915_READ(GEN6_STOLEN_RESERVED);
> +
> +	DRM_DEBUG_DRIVER("GEN6_STOLEN_RESERVED = %x\n", reg_val);
>  
>  	if ((reg_val & GEN6_STOLEN_RESERVED_ENABLE) == 0) {
>  		*base = 0;
> @@ -298,11 +344,14 @@ static void chv_get_stolen_reserved(struct drm_i915_private *dev_priv,
>  }
>  
>  static void bdw_get_stolen_reserved(struct drm_i915_private *dev_priv,
> -				    resource_size_t *base, resource_size_t *size)
> +				    resource_size_t *base,
> +				    resource_size_t *size)
>  {
> -	uint32_t reg_val = I915_READ(GEN6_STOLEN_RESERVED);
> +	u32 reg_val = I915_READ(GEN6_STOLEN_RESERVED);
>  	resource_size_t stolen_top;
>  
> +	DRM_DEBUG_DRIVER("GEN6_STOLEN_RESERVED = %x\n", reg_val);
> +
>  	if ((reg_val & GEN6_STOLEN_RESERVED_ENABLE) == 0) {
>  		*base = 0;
>  		*size = 0;
> @@ -373,8 +422,12 @@ int i915_gem_init_stolen(struct drm_i915_private *dev_priv)
>  					 &reserved_base, &reserved_size);
>  		break;
>  	case 7:
> -		gen7_get_stolen_reserved(dev_priv,
> -					 &reserved_base, &reserved_size);
> +		if (IS_VALLEYVIEW(dev_priv))
> +			vlv_get_stolen_reserved(dev_priv,
> +						&reserved_base, &reserved_size);
> +		else
> +			gen7_get_stolen_reserved(dev_priv,
> +						 &reserved_base, &reserved_size);
>  		break;
>  	default:
>  		if (IS_LP(dev_priv))
> @@ -386,9 +439,13 @@ int i915_gem_init_stolen(struct drm_i915_private *dev_priv)
>  		break;
>  	}
>  
> -	/* It is possible for the reserved base to be zero, but the register
> -	 * field for size doesn't have a zero option. */
> -	if (reserved_base == 0) {
> +	/*
> +	 * Our expectation is that the reserved space is at the top of the
> +	 * stolen region and *never* at the bottom.
> +	 */
> +	if (reserved_size && !reserved_base) {
> +		DRM_ERROR("inconsistent reservation %pa + %pa; ignoring\n",
> +			  &reserved_base, &reserved_size);
>  		reserved_size = 0;
>  		reserved_base = stolen_top;
>  	}
> -- 
> 2.16.2

-- 
Ville Syrjälä
Intel OTC


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