drm/i915/guc: write wopcm related register once during uc init

The wopcm registers are write-once, so any write after the first one
will just be ignored. The registers survive a GPU reset but not
always a suspend/resume cycle, so to keep things simple keep the
writes in the intel_uc_init_hw function instead of moving it earlier
to make sure we attempt them every time we try to load GuC.

Cc: Jeff McGee <jeff.mcgee@intel.com>
Cc: Anusha Srivatsa <anusha.srivatsa@intel.com>
Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1491524332-23860-1-git-send-email-daniele.ceraolospurio@intel.com

drivers/gpu/drm/i915/intel_guc_loader.c

@@ -285,10 +285,6 @@ static int guc_ucode_xfer(struct drm_i915_private *dev_priv)
 
 	intel_uncore_forcewake_get(dev_priv, FORCEWAKE_ALL);
 
-	/* init WOPCM */
-	I915_WRITE(GUC_WOPCM_SIZE, intel_guc_wopcm_size(dev_priv));
-	I915_WRITE(DMA_GUC_WOPCM_OFFSET, GUC_WOPCM_OFFSET_VALUE);
-
 	/* Enable MIA caching. GuC clock gating is disabled. */
 	I915_WRITE(GUC_SHIM_CONTROL, GUC_SHIM_CONTROL_VALUE);
 

drivers/gpu/drm/i915/intel_huc.c

@@ -106,11 +106,6 @@ static int huc_ucode_xfer(struct drm_i915_private *dev_priv)
 
 	intel_uncore_forcewake_get(dev_priv, FORCEWAKE_ALL);
 
-	/* init WOPCM */
-	I915_WRITE(GUC_WOPCM_SIZE, intel_guc_wopcm_size(dev_priv));
-	I915_WRITE(DMA_GUC_WOPCM_OFFSET, GUC_WOPCM_OFFSET_VALUE |
-			HUC_LOADING_AGENT_GUC);
-
 	/* Set the source address for the uCode */
 	offset = guc_ggtt_offset(vma) + huc_fw->header_offset;
 	I915_WRITE(DMA_ADDR_0_LOW, lower_32_bits(offset));

drivers/gpu/drm/i915/intel_uc.c

@@ -274,6 +274,11 @@ int intel_uc_init_hw(struct drm_i915_private *dev_priv)
 			goto err_guc;
 	}
 
+	/* init WOPCM */
+	I915_WRITE(GUC_WOPCM_SIZE, intel_guc_wopcm_size(dev_priv));
+	I915_WRITE(DMA_GUC_WOPCM_OFFSET,
+		   GUC_WOPCM_OFFSET_VALUE | HUC_LOADING_AGENT_GUC);
+
 	/* WaEnableuKernelHeaderValidFix:skl */
 	/* WaEnableGuCBootHashCheckNotSet:skl,bxt,kbl */
 	if (IS_GEN9(dev_priv))