[PATCH v6 11/11] lib: Add genxml annotated batch buffer decode

[Jan Maslak <jan.maslak@intel.com>]

When IGT_BB_ANNOTATE=1 is set, intel_bb_dump() writes a companion
<filename>.annotated file alongside the raw hex dump.  The annotated file
identifies each command and prints its field names and values, decoded via
the genxml *_decode.h headers.

The opt-in environment variable avoids file I/O overhead in normal test runs.
A disclaimer in the file header notes that the decode is best-effort and may
lag hardware on newer platforms.

Signed-off-by: Jan Maslak <jan.maslak@intel.com>
Reviewed-by: Zbigniew Kempczyński <zbigniew.kempczynski@intel.com>
---
 lib/intel_batchbuffer.c | 32 +++++++++++++++++++++++++++++++-
 1 file changed, 31 insertions(+), 1 deletion(-)

diff --git a/lib/intel_batchbuffer.c b/lib/intel_batchbuffer.c
index 912b936e0c..1dacfdc6c7 100644
--- a/lib/intel_batchbuffer.c
+++ b/lib/intel_batchbuffer.c
@@ -42,6 +42,7 @@
 #include "intel_batchbuffer.h"
 #include "intel_bufops.h"
 #include "intel_chipset.h"
+#include "intel/genxml/igt_genxml_decode.h"
 #include "intel_pat.h"
 #include "media_fill.h"
 #include "media_spin.h"
@@ -1611,7 +1612,9 @@ void intel_bb_print(struct intel_bb *ibb)
  * @filename: name to which write bb
  * @in_hex: dump bb in hex form
  *
- * Dump batch bo to file.
+ * Dump batch bo to file.  When IGT_BB_ANNOTATE=1 is set, also writes
+ * a companion annotated file (filename + ".annotated") with
+ * genxml-decoded field names and values.
  */
 void intel_bb_dump(struct intel_bb *ibb, const char *filename, bool in_hex)
 {
@@ -1641,6 +1644,33 @@ void intel_bb_dump(struct intel_bb *ibb, const char *filename, bool in_hex)
 	}
 	fclose(out);
 
+	/* Write a companion annotated decode alongside the raw dump,
+	 * but only when explicitly requested via IGT_BB_ANNOTATE=1.
+	 */
+	if (getenv("IGT_BB_ANNOTATE")) {
+		char *ann_filename;
+		unsigned batch_dwords;
+
+		igt_assert(asprintf(&ann_filename, "%s.annotated", filename) > 0);
+		batch_dwords = intel_bb_offset(ibb) / sizeof(uint32_t);
+
+		out = fopen(ann_filename, "w");
+		if (out) {
+			fprintf(out,
+				"# Batch buffer annotated decode\n"
+				"# Decoded using IGT's genxml definitions.\n"
+				"# This is a best-effort annotation and may be inaccurate,\n"
+				"# especially on newer platforms where the XML definitions\n"
+				"# may not yet reflect the latest hardware changes.\n"
+				"\n");
+			igt_genxml_decode_batch(out, ibb->devid,
+						(const uint32_t *)ptr,
+						batch_dwords);
+			fclose(out);
+		}
+		free(ann_filename);
+	}
+
 	if (ptr != ibb->batch)
 		munmap(ptr, ibb->size);
 }
-- 
2.43.0