[PATCH 4/4] drm/i915/wopcm: Don't fail on WOPCM partitioning failure

[Chris Wilson]

From: Michal Wajdeczko <michal.wajdeczko at intel.com>

We don't have to immediately fail on WOPCM partitioning, we can wait
until we will start programming WOPCM registers. This should give us
more options if we decide to restore fallback in case of GuC failures.

v3: 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>
Reviewed-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/gt/uc/intel_uc.c |  5 +++++
 drivers/gpu/drm/i915/i915_gem.c       |  6 +-----
 drivers/gpu/drm/i915/intel_wopcm.c    | 28 +++++++++++++--------------
 drivers/gpu/drm/i915/intel_wopcm.h    |  2 +-
 4 files changed, 21 insertions(+), 20 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/uc/intel_uc.c b/drivers/gpu/drm/i915/gt/uc/intel_uc.c
index 1d21c2646831..6051fd0c4554 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_uc.c
+++ b/drivers/gpu/drm/i915/gt/uc/intel_uc.c
@@ -380,6 +380,11 @@ static int uc_init_wopcm(struct intel_uc *uc)
 	u32 mask;
 	int err;
 
+	if (unlikely(!base || !size)) {
+		i915_probe_error(gt->i915, "Unsuccessful WOPCM partitioning\n");
+		return -E2BIG;
+	}
+
 	GEM_BUG_ON(!intel_uc_supports_guc(uc));
 	GEM_BUG_ON(!(base & GUC_WOPCM_OFFSET_MASK));
 	GEM_BUG_ON(base & ~GUC_WOPCM_OFFSET_MASK);
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index dbd00b11ab75..f3bb4d3ed470 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1441,10 +1441,7 @@ int i915_gem_init(struct drm_i915_private *dev_priv)
 		return ret;
 
 	intel_uc_fetch_firmwares(&dev_priv->gt.uc);
-
-	ret = intel_wopcm_init(&dev_priv->wopcm);
-	if (ret)
-		goto err_uc_fw;
+	intel_wopcm_init(&dev_priv->wopcm);
 
 	/* This is just a security blanket to placate dragons.
 	 * On some systems, we very sporadically observe that the first TLBs
@@ -1568,7 +1565,6 @@ int i915_gem_init(struct drm_i915_private *dev_priv)
 	intel_uncore_forcewake_put(&dev_priv->uncore, FORCEWAKE_ALL);
 	mutex_unlock(&dev_priv->drm.struct_mutex);
 
-err_uc_fw:
 	intel_uc_cleanup_firmwares(&dev_priv->gt.uc);
 
 	if (ret != -EIO) {
diff --git a/drivers/gpu/drm/i915/intel_wopcm.c b/drivers/gpu/drm/i915/intel_wopcm.c
index 291881937d97..4c22143ee84f 100644
--- a/drivers/gpu/drm/i915/intel_wopcm.c
+++ b/drivers/gpu/drm/i915/intel_wopcm.c
@@ -156,12 +156,10 @@ static inline int check_hw_restriction(struct drm_i915_private *i915,
  * This function will partition WOPCM space based on GuC and HuC firmware sizes
  * and will allocate max remaining for use by GuC. This function will also
  * enforce platform dependent hardware restrictions on GuC WOPCM offset and
- * size. It will fail the WOPCM init if any of these checks were failed, so that
- * the following GuC firmware uploading would be aborted.
- *
- * Return: 0 on success, non-zero error code on failure.
+ * size. It will fail the WOPCM init if any of these checks fail, so that the
+ * following WOPCM registers setup and GuC firmware uploading would be aborted.
  */
-int intel_wopcm_init(struct intel_wopcm *wopcm)
+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);
@@ -173,23 +171,25 @@ int intel_wopcm_init(struct intel_wopcm *wopcm)
 	int err;
 
 	if (!USES_GUC(i915))
-		return 0;
+		return;
 
 	GEM_BUG_ON(!wopcm->size);
+	GEM_BUG_ON(wopcm->guc.base);
+	GEM_BUG_ON(wopcm->guc.size);
 
 	if (i915_inject_probe_failure(i915))
-		return -E2BIG;
+		return;
 
 	if (guc_fw_size >= wopcm->size) {
 		DRM_ERROR("GuC FW (%uKiB) is too big to fit in WOPCM.",
 			  guc_fw_size / 1024);
-		return -E2BIG;
+		return;
 	}
 
 	if (huc_fw_size >= wopcm->size) {
 		DRM_ERROR("HuC FW (%uKiB) is too big to fit in WOPCM.",
 			  huc_fw_size / 1024);
-		return -E2BIG;
+		return;
 	}
 
 	guc_wopcm_base = ALIGN(huc_fw_size + WOPCM_RESERVED_SIZE,
@@ -197,7 +197,7 @@ int intel_wopcm_init(struct intel_wopcm *wopcm)
 	if ((guc_wopcm_base + ctx_rsvd) >= wopcm->size) {
 		DRM_ERROR("GuC WOPCM base (%uKiB) is too big.\n",
 			  guc_wopcm_base / 1024);
-		return -E2BIG;
+		return;
 	}
 
 	guc_wopcm_size = wopcm->size - guc_wopcm_base - ctx_rsvd;
@@ -211,16 +211,16 @@ int intel_wopcm_init(struct intel_wopcm *wopcm)
 		DRM_ERROR("Need %uKiB WOPCM for GuC, %uKiB available.\n",
 			  (guc_fw_size + guc_wopcm_rsvd) / 1024,
 			  guc_wopcm_size / 1024);
-		return -E2BIG;
+		return;
 	}
 
 	err = check_hw_restriction(i915, guc_wopcm_base, guc_wopcm_size,
 				   huc_fw_size);
 	if (err)
-		return err;
+		return;
 
 	wopcm->guc.base = guc_wopcm_base;
 	wopcm->guc.size = guc_wopcm_size;
-
-	return 0;
+	GEM_BUG_ON(!wopcm->guc.base);
+	GEM_BUG_ON(!wopcm->guc.size);
 }
diff --git a/drivers/gpu/drm/i915/intel_wopcm.h b/drivers/gpu/drm/i915/intel_wopcm.h
index f9b603205bb1..17d6aa86008a 100644
--- a/drivers/gpu/drm/i915/intel_wopcm.h
+++ b/drivers/gpu/drm/i915/intel_wopcm.h
@@ -55,6 +55,6 @@ static inline u32 intel_wopcm_guc_size(struct intel_wopcm *wopcm)
 }
 
 void intel_wopcm_init_early(struct intel_wopcm *wopcm);
-int intel_wopcm_init(struct intel_wopcm *wopcm);
+void intel_wopcm_init(struct intel_wopcm *wopcm);
 
 #endif
-- 
2.23.0.rc0