[Intel-gfx] [PATCH 3/5] drm/i915/wopcm: Try to use already locked WOPCM layout

[Daniele Ceraolo Spurio]

On 8/15/19 10:12 AM, Michal Wajdeczko wrote:
> If WOPCM layout is already locked in HW we shouldn't continue
> with our own partitioning as it could be likely different and
> we will be unable to enforce it and fail. Instead we should try
> to reuse what is already programmed, maybe there will be a fit.
> 
> This should enable us to reload driver with slightly different
> HuC firmware (or even without HuC) without need to reboot.
> 
> v2: reordered/rebased
> 
> Signed-off-by: Michal Wajdeczko <michal.wajdeczko at intel.com>
> Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
> Cc: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Michal Winiarski <michal.winiarski at intel.com>

Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>

Daniele

> ---
>   drivers/gpu/drm/i915/intel_wopcm.c | 29 +++++++++++++++++++++++++++--
>   1 file changed, 27 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_wopcm.c b/drivers/gpu/drm/i915/intel_wopcm.c
> index 3ac05055bb08..ea02efb653a7 100644
> --- a/drivers/gpu/drm/i915/intel_wopcm.c
> +++ b/drivers/gpu/drm/i915/intel_wopcm.c
> @@ -212,6 +212,21 @@ static inline bool __check_layout(struct drm_i915_private *i915, u32 wopcm_size,
>   				     huc_fw_size);
>   }
>   
> +static bool __wopcm_regs_locked(struct intel_uncore *uncore,
> +				u32 *guc_wopcm_base, u32 *guc_wopcm_size)
> +{
> +	u32 reg_base = intel_uncore_read(uncore, DMA_GUC_WOPCM_OFFSET);
> +	u32 reg_size = intel_uncore_read(uncore, GUC_WOPCM_SIZE);
> +
> +	if (!(reg_size & GUC_WOPCM_SIZE_LOCKED) ||
> +	    !(reg_base & GUC_WOPCM_OFFSET_VALID))
> +		return false;
> +
> +	*guc_wopcm_base = reg_base & GUC_WOPCM_OFFSET_MASK;
> +	*guc_wopcm_size = reg_size & GUC_WOPCM_SIZE_MASK;
> +	return true;
> +}
> +
>   /**
>    * intel_wopcm_init() - Initialize the WOPCM structure.
>    * @wopcm: pointer to intel_wopcm.
> @@ -225,8 +240,9 @@ static inline bool __check_layout(struct drm_i915_private *i915, u32 wopcm_size,
>   void intel_wopcm_init(struct intel_wopcm *wopcm)
>   {
>   	struct drm_i915_private *i915 = wopcm_to_i915(wopcm);
> -	u32 guc_fw_size = intel_uc_fw_get_upload_size(&i915->gt.uc.guc.fw);
> -	u32 huc_fw_size = intel_uc_fw_get_upload_size(&i915->gt.uc.huc.fw);
> +	struct intel_gt *gt = &i915->gt;
> +	u32 guc_fw_size = intel_uc_fw_get_upload_size(&gt->uc.guc.fw);
> +	u32 huc_fw_size = intel_uc_fw_get_upload_size(&gt->uc.huc.fw);
>   	u32 ctx_rsvd = context_reserved_size(i915);
>   	u32 guc_wopcm_base;
>   	u32 guc_wopcm_size;
> @@ -244,6 +260,14 @@ void intel_wopcm_init(struct intel_wopcm *wopcm)
>   	if (i915_inject_probe_failure(i915))
>   		return;
>   
> +	if (__wopcm_regs_locked(gt->uncore, &guc_wopcm_base, &guc_wopcm_size)) {
> +		DRM_DEV_DEBUG_DRIVER(i915->drm.dev,
> +				     "GuC WOPCM is already locked [%uK, %uK)\n",
> +				     guc_wopcm_base / SZ_1K,
> +				     guc_wopcm_size / SZ_1K);
> +		goto check;
> +	}
> +
>   	guc_wopcm_base = ALIGN(huc_fw_size + WOPCM_RESERVED_SIZE,
>   			       GUC_WOPCM_OFFSET_ALIGNMENT);
>   	guc_wopcm_base = max(wopcm->size - ctx_rsvd, guc_wopcm_base);
> @@ -254,6 +278,7 @@ void intel_wopcm_init(struct intel_wopcm *wopcm)
>   			     "Calculated GuC WOPCM Region: [%uKiB, %uKiB)\n",
>   			     guc_wopcm_base / SZ_1K, guc_wopcm_size / SZ_1K);
>   
> +check:
>   	if (__check_layout(i915, wopcm->size, guc_wopcm_base, guc_wopcm_size,
>   			   guc_fw_size, huc_fw_size)) {
>   		wopcm->guc.base = guc_wopcm_base;
>