[PATCH 1/2] drm/xe/guc: Add helpers for GuC KLVs

[Michal Wajdeczko <michal.wajdeczko@intel.com>]

Many of the GuC actions use KLVs to pass additional parameters or
configuration data. Add few helper functions for better reporting
any information related to KLVs.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
---
 drivers/gpu/drm/xe/Makefile             |   1 +
 drivers/gpu/drm/xe/xe_guc_klv_helpers.c | 133 ++++++++++++++++++++++++
 drivers/gpu/drm/xe/xe_guc_klv_helpers.h |  51 +++++++++
 3 files changed, 185 insertions(+)
 create mode 100644 drivers/gpu/drm/xe/xe_guc_klv_helpers.c
 create mode 100644 drivers/gpu/drm/xe/xe_guc_klv_helpers.h

diff --git a/drivers/gpu/drm/xe/Makefile b/drivers/gpu/drm/xe/Makefile
index e5b1715f721e..ec0d1fb49b1e 100644
--- a/drivers/gpu/drm/xe/Makefile
+++ b/drivers/gpu/drm/xe/Makefile
@@ -98,6 +98,7 @@ xe-y += xe_bb.o \
 	xe_guc_debugfs.o \
 	xe_guc_hwconfig.o \
 	xe_guc_id_mgr.o \
+	xe_guc_klv_helpers.o \
 	xe_guc_log.o \
 	xe_guc_pc.o \
 	xe_guc_submit.o \
diff --git a/drivers/gpu/drm/xe/xe_guc_klv_helpers.c b/drivers/gpu/drm/xe/xe_guc_klv_helpers.c
new file mode 100644
index 000000000000..c39fda08afcb
--- /dev/null
+++ b/drivers/gpu/drm/xe/xe_guc_klv_helpers.c
@@ -0,0 +1,133 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2024 Intel Corporation
+ */
+
+#include <linux/bitfield.h>
+#include <drm/drm_print.h>
+
+#include "abi/guc_klvs_abi.h"
+#include "xe_guc_klv_helpers.h"
+
+#define make_u64(hi, lo) ((u64)((u64)(u32)(hi) << 32 | (u32)(lo)))
+
+/**
+ * xe_guc_klv_key_to_string - Convert KLV key into friendly name.
+ * @key: the `GuC KLV`_ key
+ *
+ * Return: name of the KLV key.
+ */
+const char *xe_guc_klv_key_to_string(u16 key)
+{
+	switch (key) {
+	/* VGT POLICY keys */
+	case GUC_KLV_VGT_POLICY_SCHED_IF_IDLE_KEY:
+		return "sched_if_idle";
+	case GUC_KLV_VGT_POLICY_ADVERSE_SAMPLE_PERIOD_KEY:
+		return "sample_period";
+	case GUC_KLV_VGT_POLICY_RESET_AFTER_VF_SWITCH_KEY:
+		return "reset_engine";
+	/* VF CFG keys */
+	case GUC_KLV_VF_CFG_GGTT_START_KEY:
+		return "ggtt_start";
+	case GUC_KLV_VF_CFG_GGTT_SIZE_KEY:
+		return "ggtt_size";
+	case GUC_KLV_VF_CFG_LMEM_SIZE_KEY:
+		return "lmem_size";
+	case GUC_KLV_VF_CFG_NUM_CONTEXTS_KEY:
+		return "num_contexts";
+	case GUC_KLV_VF_CFG_TILE_MASK_KEY:
+		return "tile_mask";
+	case GUC_KLV_VF_CFG_NUM_DOORBELLS_KEY:
+		return "num_doorbells";
+	case GUC_KLV_VF_CFG_EXEC_QUANTUM_KEY:
+		return "exec_quantum";
+	case GUC_KLV_VF_CFG_PREEMPT_TIMEOUT_KEY:
+		return "preempt_timeout";
+	case GUC_KLV_VF_CFG_BEGIN_DOORBELL_ID_KEY:
+		return "begin_db_id";
+	case GUC_KLV_VF_CFG_BEGIN_CONTEXT_ID_KEY:
+		return "begin_ctx_id";
+	}
+	return "(unknown)";
+}
+
+/**
+ * xe_guc_klv_print - Print content of the buffer with `GuC KLV`_.
+ * @klvs: the buffer with KLVs
+ * @num_dwords: number of dwords (u32) available in the buffer
+ * @p: the &drm_printer
+ *
+ * The buffer may contain more than one KLV.
+ */
+void xe_guc_klv_print(const u32 *klvs, u32 num_dwords, struct drm_printer *p)
+{
+	while (num_dwords >= GUC_KLV_LEN_MIN) {
+		u32 key = FIELD_GET(GUC_KLV_0_KEY, klvs[0]);
+		u32 len = FIELD_GET(GUC_KLV_0_LEN, klvs[0]);
+
+		klvs += GUC_KLV_LEN_MIN;
+		num_dwords -= GUC_KLV_LEN_MIN;
+
+		if (num_dwords < len) {
+			drm_printf(p, "{ key %#06x : truncated %zu of %zu bytes %*ph } # %s\n",
+				   key, num_dwords * sizeof(u32), len * sizeof(u32),
+				   (int)(num_dwords * sizeof(u32)), klvs,
+				   xe_guc_klv_key_to_string(key));
+			return;
+		}
+
+		switch (len) {
+		case 0:
+			drm_printf(p, "{ key %#06x : no value } # %s\n",
+				   key, xe_guc_klv_key_to_string(key));
+			break;
+		case 1:
+			drm_printf(p, "{ key %#06x : 32b value %u } # %s\n",
+				   key, klvs[0], xe_guc_klv_key_to_string(key));
+			break;
+		case 2:
+			drm_printf(p, "{ key %#06x : 64b value %#llx } # %s\n",
+				   key, make_u64(klvs[1], klvs[0]),
+				   xe_guc_klv_key_to_string(key));
+			break;
+		default:
+			drm_printf(p, "{ key %#06x : %zu bytes %*ph } # %s\n",
+				   key, len * sizeof(u32), (int)(len * sizeof(u32)),
+				   klvs, xe_guc_klv_key_to_string(key));
+			break;
+		}
+
+		klvs += len;
+		num_dwords -= len;
+	}
+
+	/* we don't expect any leftovers, fix if KLV header is ever changed */
+	BUILD_BUG_ON(GUC_KLV_LEN_MIN > 1);
+}
+
+/**
+ * xe_guc_klv_count - Count KLVs present in the buffer.
+ * @klvs: the buffer with KLVs
+ * @num_dwords: number of dwords (u32) in the buffer
+ *
+ * Return: number of recognized KLVs or
+ *          a negative error code if KLV buffer is truncated.
+ */
+int xe_guc_klv_count(const u32 *klvs, u32 num_dwords)
+{
+	int num_klvs = 0;
+
+	while (num_dwords >= GUC_KLV_LEN_MIN) {
+		u32 len = FIELD_GET(GUC_KLV_0_LEN, klvs[0]);
+
+		if (num_dwords < len + GUC_KLV_LEN_MIN)
+			return -ENODATA;
+
+		klvs += GUC_KLV_LEN_MIN + len;
+		num_dwords -= GUC_KLV_LEN_MIN + len;
+		num_klvs++;
+	}
+
+	return num_dwords ? -ENODATA : num_klvs;
+}
diff --git a/drivers/gpu/drm/xe/xe_guc_klv_helpers.h b/drivers/gpu/drm/xe/xe_guc_klv_helpers.h
new file mode 100644
index 000000000000..b835e0ebe6db
--- /dev/null
+++ b/drivers/gpu/drm/xe/xe_guc_klv_helpers.h
@@ -0,0 +1,51 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright © 2024 Intel Corporation
+ */
+
+#ifndef _XE_GUC_KLV_HELPERS_H_
+#define _XE_GUC_KLV_HELPERS_H_
+
+#include <linux/types.h>
+
+struct drm_printer;
+
+const char *xe_guc_klv_key_to_string(u16 key);
+
+void xe_guc_klv_print(const u32 *klvs, u32 num_dwords, struct drm_printer *p);
+int xe_guc_klv_count(const u32 *klvs, u32 num_dwords);
+
+/**
+ * PREP_GUC_KLV - Prepare KLV header value based on provided key and len.
+ * @key: KLV key
+ * @len: KLV length
+ *
+ * Return: value of the KLV header (u32).
+ */
+#define PREP_GUC_KLV(key, len) \
+	(FIELD_PREP(GUC_KLV_0_KEY, (key)) | \
+	 FIELD_PREP(GUC_KLV_0_LEN, (len)))
+
+/**
+ * PREP_GUC_KLV_CONST - Prepare KLV header value based on const key and len.
+ * @key: const KLV key
+ * @len: const KLV length
+ *
+ * Return: value of the KLV header (u32).
+ */
+#define PREP_GUC_KLV_CONST(key, len) \
+	(FIELD_PREP_CONST(GUC_KLV_0_KEY, (key)) | \
+	 FIELD_PREP_CONST(GUC_KLV_0_LEN, (len)))
+
+/**
+ * PREP_GUC_KLV_TAG - Prepare KLV header value based on unique KLV definition tag.
+ * @TAG: unique tag of the KLV definition
+ *
+ * Combine separate KEY and LEN definitions of the KLV identified by the TAG.
+ *
+ * Return: value of the KLV header (u32).
+ */
+#define PREP_GUC_KLV_TAG(TAG) \
+	PREP_GUC_KLV_CONST(GUC_KLV_##TAG##_KEY, GUC_KLV_##TAG##_LEN)
+
+#endif
-- 
2.43.0