pan/decode: Rotate trace files

Reviewed-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Tested-by: Marge Bot <https://gitlab.freedesktop.org/mesa/mesa/merge_requests/3525>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/merge_requests/3525>

src/gallium/drivers/panfrost/pan_context.c

@@ -52,6 +52,7 @@
 #include "pan_blending.h"
 #include "pan_blend_shaders.h"
 #include "pan_util.h"
+#include "pandecode/decode.h"
 
 struct midgard_tiler_descriptor
 panfrost_emit_midg_tiler(struct panfrost_batch *batch, unsigned vertex_count)
@@ -1327,6 +1328,9 @@ panfrost_flush(
 
                 util_dynarray_fini(&fences);
         }
+
+        if (pan_debug & PAN_DBG_TRACE)
+                pandecode_next_frame();
 }
 
 #define DEFINE_CASE(c) case PIPE_PRIM_##c: return MALI_##c;

src/panfrost/pandecode/common.c

@@ -116,20 +116,28 @@ pointer_as_memory_reference(uint64_t ptr)
 
 }
 
+static int pandecode_dump_frame_count = 0;
+
 static void
 pandecode_dump_file_open(void)
 {
         if (pandecode_dump_stream)
                 return;
 
-        const char *dump_file = debug_get_option("PANDECODE_DUMP_FILE", "pandecode.dump");
+        char buffer[1024];
 
-        printf("pandecode: dump command stream to file %s\n", dump_file);
+        /* This does a getenv every frame, so it is possible to use
-        pandecode_dump_stream = fopen(dump_file, "w");
+         * setenv to change the base at runtime.
+         */
+        const char *dump_file_base = debug_get_option("PANDECODE_DUMP_FILE", "pandecode.dump");
+        snprintf(buffer, sizeof(buffer), "%s.%04d", dump_file_base, pandecode_dump_frame_count);
+
+        printf("pandecode: dump command stream to file %s\n", buffer);
+        pandecode_dump_stream = fopen(buffer, "w");
 
         if (!pandecode_dump_stream)
                 fprintf(stderr,"pandecode: failed to open command stream log file %s\n",
-                        dump_file);
+                        buffer);
 }
 
 static void
@@ -148,6 +156,14 @@ pandecode_initialize(void)
         pandecode_dump_file_open();
 }
 
+void
+pandecode_next_frame(void)
+{
+        pandecode_dump_file_close();
+        pandecode_dump_frame_count++;
+        pandecode_dump_file_open();
+}
+
 void
 pandecode_close(void)
 {

src/panfrost/pandecode/public.h

@@ -44,6 +44,8 @@
 
 void pandecode_initialize(void);
 
+void pandecode_next_frame(void);
+
 void pandecode_close(void);
 
 void