fd: make RD dump output path configurable through FD_RD_DUMP_PATH

Allow adjusting the location of RD dumps and trigger file through the
FD_RD_DUMP_PATH environment variable. When not present, the existing
defaults will be used.

Signed-off-by: Zan Dobersek <zdobersek@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/40532>

docs/drivers/freedreno.rst

@@ -407,9 +407,10 @@ capture from inside Mesa. Different ``FD_RD_DUMP`` options are available:
   of that many subsequent submits. Writing -1 will enable dumping of submits
   until disabled. Writing 0 (or any other value) will disable dumps.
 
-Output dump files and trigger file (when enabled) are hard-coded to be placed
-under ``/tmp``, or ``/data/local/tmp`` under Android. `FD_RD_DUMP_TESTNAME` can
-be used to specify a more descriptive prefix for the output or trigger files.
+Output dump files and trigger file (when enabled) are placed under ``/tmp`` or
+``/data/local/tmp`` under Android by default, but that location can be adjusted
+through ``FD_RD_DUMP_PATH``. ``FD_RD_DUMP_TESTNAME`` can be used to specify a
+more descriptive prefix for the output or trigger files.
 
 Dumping can be limited to specific ranges of frames or submits. For example,
 ``FD_RD_DUMP_SUBMITS=120-140,160,165`` will dump command streams only for the

src/freedreno/common/freedreno_rd_output.c

@@ -20,12 +20,6 @@
 #include "util/u_atomic.h"
 #include "util/u_debug.h"
 
-#if DETECT_OS_ANDROID
-static const char *fd_rd_output_base_path = "/data/local/tmp";
-#else
-static const char *fd_rd_output_base_path = "/tmp";
-#endif
-
 static const struct debug_control fd_rd_dump_options[] = {
    { "enable", FD_RD_DUMP_ENABLE },
    { "combine", FD_RD_DUMP_COMBINE },
@@ -52,6 +46,18 @@ fd_rd_dump_env_init_once(void)
     */
    if (fd_rd_dump_env.flags & ~FD_RD_DUMP_ENABLE)
       fd_rd_dump_env.flags |= FD_RD_DUMP_ENABLE;
+
+   const char *output_path_value = os_get_option("FD_RD_DUMP_PATH");
+   if (!output_path_value) {
+      output_path_value =
+#if DETECT_OS_ANDROID
+         "/data/local/tmp";
+#else
+         "/tmp";
+#endif
+   }
+   snprintf(fd_rd_dump_env.output_path, sizeof(fd_rd_dump_env.output_path),
+      "%s", output_path_value);
 }
 
 void
@@ -172,14 +178,14 @@ fd_rd_output_init(struct fd_rd_output *output, const char* output_name)
 
       char file_path[PATH_MAX];
       snprintf(file_path, sizeof(file_path), "%s/%s_combined.rd.gz",
-               fd_rd_output_base_path, output->name);
+               fd_rd_dump_env.output_path, output->name);
       output->file = gzopen(file_path, "w");
    }
 
    if (FD_RD_DUMP(TRIGGER)) {
       char file_path[PATH_MAX];
       snprintf(file_path, sizeof(file_path), "%s/%s_trigger",
-               fd_rd_output_base_path, output->name);
+               fd_rd_dump_env.output_path, output->name);
       output->trigger_fd = open(file_path, O_RDWR | O_CREAT | O_TRUNC, 0600);
    }
 
@@ -205,7 +211,7 @@ fd_rd_output_fini(struct fd_rd_output *output)
        */
       char file_path[PATH_MAX];
       snprintf(file_path, sizeof(file_path), "%s/%s_trigger",
-               fd_rd_output_base_path, output->name);
+               fd_rd_dump_env.output_path, output->name);
       unlink(file_path);
    }
 
@@ -302,10 +308,10 @@ fd_rd_output_begin(struct fd_rd_output *output, uint32_t frame, uint32_t submit)
    char file_path[PATH_MAX];
    if (frame != UINT_MAX) {
       snprintf(file_path, sizeof(file_path), "%s/%s_frame%.5d_submit%.5d.rd",
-               fd_rd_output_base_path, output->name, frame, submit);
+               fd_rd_dump_env.output_path, output->name, frame, submit);
    } else {
       snprintf(file_path, sizeof(file_path), "%s/%s_submit%.5d.rd",
-               fd_rd_output_base_path, output->name, submit);
+               fd_rd_dump_env.output_path, output->name, submit);
    }
    output->file = gzopen(file_path, "w");
    return true;

src/freedreno/common/freedreno_rd_output.h

@@ -26,6 +26,7 @@ enum fd_rd_dump_flags {
 
 struct fd_rd_dump_env {
    uint32_t flags;
+   char output_path[PATH_MAX];
 };
 
 extern struct fd_rd_dump_env fd_rd_dump_env;