[Intel-gfx] [PATCH v2 01/16] drm/i915/guc: Add support for data reporting in GuC responses

[Michal Wajdeczko]

GuC may return additional data in the command status response.
Format and meaning of this data is action specific.
We will use this non-negative data as a new success return value.
Currently used actions don't return data that way yet.

v2: fix prohibited space after '~' (Michel)
    update commit message (Daniele)

Signed-off-by: Michal Wajdeczko <michal.wajdeczko at intel.com>
Cc: Oscar Mateo <oscar.mateo at intel.com>
Cc: Michel Thierry <michel.thierry at intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
---
 drivers/gpu/drm/i915/intel_guc_ct.c   | 14 +++++++-------
 drivers/gpu/drm/i915/intel_guc_fwif.h |  6 ++++++
 drivers/gpu/drm/i915/intel_uc.c       |  5 ++++-
 3 files changed, 17 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_guc_ct.c b/drivers/gpu/drm/i915/intel_guc_ct.c
index c4cbec1..1249868 100644
--- a/drivers/gpu/drm/i915/intel_guc_ct.c
+++ b/drivers/gpu/drm/i915/intel_guc_ct.c
@@ -387,9 +387,9 @@ static int ctch_send(struct intel_guc *guc,
 	err = wait_for_response(desc, fence, status);
 	if (unlikely(err))
 		return err;
-	if (*status != INTEL_GUC_STATUS_SUCCESS)
+	if (INTEL_GUC_RECV_TO_STATUS(*status) != INTEL_GUC_STATUS_SUCCESS)
 		return -EIO;
-	return 0;
+	return INTEL_GUC_RECV_TO_DATA(*status);
 }
 
 /*
@@ -399,18 +399,18 @@ static int intel_guc_send_ct(struct intel_guc *guc, const u32 *action, u32 len)
 {
 	struct intel_guc_ct_channel *ctch = &guc->ct.host_channel;
 	u32 status = ~0; /* undefined */
-	int err;
+	int ret;
 
 	mutex_lock(&guc->send_mutex);
 
-	err = ctch_send(guc, ctch, action, len, &status);
-	if (unlikely(err)) {
+	ret = ctch_send(guc, ctch, action, len, &status);
+	if (unlikely(ret < 0)) {
 		DRM_ERROR("CT: send action %#X failed; err=%d status=%#X\n",
-			  action[0], err, status);
+			  action[0], ret, status);
 	}
 
 	mutex_unlock(&guc->send_mutex);
-	return err;
+	return ret;
 }
 
 /**
diff --git a/drivers/gpu/drm/i915/intel_guc_fwif.h b/drivers/gpu/drm/i915/intel_guc_fwif.h
index 5fa2860..367aa65 100644
--- a/drivers/gpu/drm/i915/intel_guc_fwif.h
+++ b/drivers/gpu/drm/i915/intel_guc_fwif.h
@@ -567,10 +567,16 @@ enum intel_guc_action {
  * command in SS0. The response is distinguishable from a command
  * by the fact that all the MASK bits are set. The remaining bits
  * give more detail.
+ * Bits [16:27] are reserved for optional data reporting.
  */
 #define	INTEL_GUC_RECV_MASK	((u32)0xF0000000)
 #define	INTEL_GUC_RECV_IS_RESPONSE(x)	((u32)(x) >= INTEL_GUC_RECV_MASK)
 #define	INTEL_GUC_RECV_STATUS(x)	(INTEL_GUC_RECV_MASK | (x))
+#define INTEL_GUC_RECV_DATA_SHIFT	16
+#define INTEL_GUC_RECV_DATA_MASK	(0xFFF << INTEL_GUC_RECV_DATA_SHIFT)
+#define INTEL_GUC_RECV_TO_STATUS(x)	((x) & ~INTEL_GUC_RECV_DATA_MASK)
+#define INTEL_GUC_RECV_TO_DATA(x)	(((x) & INTEL_GUC_RECV_DATA_MASK) >> \
+					 INTEL_GUC_RECV_DATA_SHIFT)
 
 /* GUC will return status back to SOFT_SCRATCH_O_REG */
 enum intel_guc_status {
diff --git a/drivers/gpu/drm/i915/intel_uc.c b/drivers/gpu/drm/i915/intel_uc.c
index 27e072c..3aa0f44 100644
--- a/drivers/gpu/drm/i915/intel_uc.c
+++ b/drivers/gpu/drm/i915/intel_uc.c
@@ -502,7 +502,7 @@ int intel_guc_send_mmio(struct intel_guc *guc, const u32 *action, u32 len)
 					   INTEL_GUC_RECV_MASK,
 					   INTEL_GUC_RECV_MASK,
 					   10, 10, &status);
-	if (status != INTEL_GUC_STATUS_SUCCESS) {
+	if (INTEL_GUC_RECV_TO_STATUS(status) != INTEL_GUC_STATUS_SUCCESS) {
 		/*
 		 * Either the GuC explicitly returned an error (which
 		 * we convert to -EIO here) or no response at all was
@@ -514,6 +514,9 @@ int intel_guc_send_mmio(struct intel_guc *guc, const u32 *action, u32 len)
 		DRM_WARN("INTEL_GUC_SEND: Action 0x%X failed;"
 			 " ret=%d status=0x%08X response=0x%08X\n",
 			 action[0], ret, status, I915_READ(SOFT_SCRATCH(15)));
+	} else {
+		/* Use data encoded by Guc in status dword as return value */
+		ret = INTEL_GUC_RECV_TO_DATA(status);
 	}
 
 	intel_uncore_forcewake_put(dev_priv, guc->send_regs.fw_domains);
-- 
2.7.4