scripts/gdb: initial clk support: lx-clk-summary

Add an lx-clk-summary command which prints a subset of
/sys/kernel/debug/clk/clk_summary.

This can be used to examine hangs caused by clk not being enabled.

Link: http://lkml.kernel.org/r/Message-ID:
Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Kieran Bingham <kbingham@kernel.org>
Cc: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

scripts/gdb/linux/clk.py

+# SPDX-License-Identifier: GPL-2.0
+#
+# Copyright (c) NXP 2019
+
+import gdb
+import sys
+
+from linux import utils, lists
+
+clk_core_type = utils.CachedType("struct clk_core")
+
+
+def clk_core_for_each_child(hlist_head):
+    return lists.hlist_for_each_entry(hlist_head,
+            clk_core_type.get_type().pointer(), "child_node")
+
+
+class LxClkSummary(gdb.Command):
+    """Print Linux kernel log buffer."""
+
+    def __init__(self):
+        super(LxClkSummary, self).__init__("lx-clk-summary", gdb.COMMAND_DATA)
+
+    def show_subtree(self, clk, level):
+        gdb.write("%*s%-*s %7d %8d %8d\n" % (
+                level * 3 + 1, "",
+                30 - level * 3,
+                clk['name'].string(),
+                clk['enable_count'],
+                clk['prepare_count'],
+                clk['protect_count']))
+
+        for child in clk_core_for_each_child(clk['children']):
+            self.show_subtree(child, level + 1)
+
+    def invoke(self, arg, from_tty):
+        gdb.write("                                 enable  prepare  protect\n")
+        gdb.write("   clock                          count    count    count\n")
+        gdb.write("---------------------------------------------------------\n")
+        for clk in clk_core_for_each_child(gdb.parse_and_eval("clk_root_list")):
+            self.show_subtree(clk, 0)
+        for clk in clk_core_for_each_child(gdb.parse_and_eval("clk_orphan_list")):
+            self.show_subtree(clk, 0)
+
+
+LxClkSummary()

scripts/gdb/vmlinux-gdb.py

@@ -34,3 +34,4 @@ else:
     import linux.proc
     import linux.constants
     import linux.timerlist
+    import linux.clk