Re: [Intel-gfx] [PATCH v4 08/18] drm/i915/xehp: Changes to ss/eu definitions

["Souza, Jose" <jose.souza@intel.com>]

On Thu, 2021-07-29 at 09:59 -0700, Matt Roper wrote:
> From: Matthew Auld <matthew.auld@intel.com>
> 
> Xe_HP no longer has "slices" in the same way that old platforms did.
> There are new concepts (gslices, cslices, mslices) that apply in various
> contexts, but for the purposes of fusing slices no longer exist and we
> just have one large pool of dual-subslices (DSS) to work with.
> Furthermore, the meaning of the DSS fuse is inverted compared to past
> platforms --- it now specifies which DSS are enabled rather than which
> ones are disabled.

Reviewed-by: José Roberto de Souza <jose.souza@intel.com>

> 
> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
> Cc: Lucas De Marchi <lucas.demarchi@intel.com>
> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
> Signed-off-by: Matthew Auld <matthew.auld@intel.com>
> Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
> Signed-off-by: Radhakrishna Sripada <radhakrishna.sripada@intel.com>
> Signed-off-by: Stuart Summers <stuart.summers@intel.com>
> Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
> Signed-off-by: Prasad Nallani <prasad.nallani@intel.com>
> ---
>  drivers/gpu/drm/i915/gt/intel_sseu.c | 24 ++++++++++++++++++++----
>  drivers/gpu/drm/i915/i915_getparam.c |  6 ++++--
>  drivers/gpu/drm/i915/i915_reg.h      |  3 +++
>  3 files changed, 27 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/gt/intel_sseu.c b/drivers/gpu/drm/i915/gt/intel_sseu.c
> index bbed8e8625e1..5d1b7d06c96b 100644
> --- a/drivers/gpu/drm/i915/gt/intel_sseu.c
> +++ b/drivers/gpu/drm/i915/gt/intel_sseu.c
> @@ -139,17 +139,33 @@ static void gen12_sseu_info_init(struct intel_gt *gt)
>  	 * Gen12 has Dual-Subslices, which behave similarly to 2 gen11 SS.
>  	 * Instead of splitting these, provide userspace with an array
>  	 * of DSS to more closely represent the hardware resource.
> +	 *
> +	 * In addition, the concept of slice has been removed in Xe_HP.
> +	 * To be compatible with prior generations, assume a single slice
> +	 * across the entire device. Then calculate out the DSS for each
> +	 * workload type within that software slice.
>  	 */
>  	intel_sseu_set_info(sseu, 1, 6, 16);
>  
> -	s_en = intel_uncore_read(uncore, GEN11_GT_SLICE_ENABLE) &
> -		GEN11_GT_S_ENA_MASK;
> +	/*
> +	 * As mentioned above, Xe_HP does not have the concept of a slice.
> +	 * Enable one for software backwards compatibility.
> +	 */
> +	if (GRAPHICS_VER_FULL(gt->i915) >= IP_VER(12, 50))
> +		s_en = 0x1;
> +	else
> +		s_en = intel_uncore_read(uncore, GEN11_GT_SLICE_ENABLE) &
> +		       GEN11_GT_S_ENA_MASK;
>  
>  	dss_en = intel_uncore_read(uncore, GEN12_GT_DSS_ENABLE);
>  
>  	/* one bit per pair of EUs */
> -	eu_en_fuse = ~(intel_uncore_read(uncore, GEN11_EU_DISABLE) &
> -		       GEN11_EU_DIS_MASK);
> +	if (GRAPHICS_VER_FULL(gt->i915) >= IP_VER(12, 50))
> +		eu_en_fuse = intel_uncore_read(uncore, XEHP_EU_ENABLE) & XEHP_EU_ENA_MASK;
> +	else
> +		eu_en_fuse = ~(intel_uncore_read(uncore, GEN11_EU_DISABLE) &
> +			       GEN11_EU_DIS_MASK);
> +
>  	for (eu = 0; eu < sseu->max_eus_per_subslice / 2; eu++)
>  		if (eu_en_fuse & BIT(eu))
>  			eu_en |= BIT(eu * 2) | BIT(eu * 2 + 1);
> diff --git a/drivers/gpu/drm/i915/i915_getparam.c b/drivers/gpu/drm/i915/i915_getparam.c
> index 24e18219eb50..e289397d9178 100644
> --- a/drivers/gpu/drm/i915/i915_getparam.c
> +++ b/drivers/gpu/drm/i915/i915_getparam.c
> @@ -15,7 +15,7 @@ int i915_getparam_ioctl(struct drm_device *dev, void *data,
>  	struct pci_dev *pdev = to_pci_dev(dev->dev);
>  	const struct sseu_dev_info *sseu = &i915->gt.info.sseu;
>  	drm_i915_getparam_t *param = data;
> -	int value;
> +	int value = 0;
>  
>  	switch (param->param) {
>  	case I915_PARAM_IRQ_ACTIVE:
> @@ -150,7 +150,9 @@ int i915_getparam_ioctl(struct drm_device *dev, void *data,
>  			return -ENODEV;
>  		break;
>  	case I915_PARAM_SUBSLICE_MASK:
> -		value = sseu->subslice_mask[0];
> +		/* Only copy bits from the first slice */
> +		memcpy(&value, sseu->subslice_mask,
> +		       min(sseu->ss_stride, (u8)sizeof(value)));
>  		if (!value)
>  			return -ENODEV;
>  		break;
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index 62af453c8c54..99858bc593f0 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -3225,6 +3225,9 @@ static inline bool i915_mmio_reg_valid(i915_reg_t reg)
>  
>  #define GEN12_GT_DSS_ENABLE _MMIO(0x913C)
>  
> +#define XEHP_EU_ENABLE			_MMIO(0x9134)
> +#define XEHP_EU_ENA_MASK		0xFF
> +
>  #define GEN6_BSD_SLEEP_PSMI_CONTROL	_MMIO(0x12050)
>  #define   GEN6_BSD_SLEEP_MSG_DISABLE	(1 << 0)
>  #define   GEN6_BSD_SLEEP_FLUSH_DISABLE	(1 << 2)