scripts/gdb: add lx-genpd-summary command

This is like /sys/kernel/debug/pm/pm_genpd_summary except it's
accessible through a debugger.

This can be useful if the target crashes or hangs because power domains
were not properly enabled.

Link: http://lkml.kernel.org/r/f9ee627[e-mail]
Signed-off-by: Leonard Crestez <[e-mail]>
Reviewed-by: Stephen Boyd <[e-mail]>
Cc: Kieran Bingham <[e-mail]>
Cc: Jan Kiszka <[e-mail]>
Cc: "Rafael J. Wysocki" <[e-mail]>
Cc: Greg Kroah-Hartman <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

scripts/gdb/linux/genpd.py

···
+# SPDX-License-Identifier: GPL-2.0
+#
+# Copyright (c) NXP 2019
+
+import gdb
+import sys
+
+from linux.utils import CachedType
+from linux.lists import list_for_each_entry
+
+generic_pm_domain_type = CachedType('struct generic_pm_domain')
+pm_domain_data_type = CachedType('struct pm_domain_data')
+device_link_type = CachedType('struct device_link')
+
+
+def kobject_get_path(kobj):
+    path = kobj['name'].string()
+    parent = kobj['parent']
+    if parent:
+        path = kobject_get_path(parent) + '/' + path
+    return path
+
+
+def rtpm_status_str(dev):
+    if dev['power']['runtime_error']:
+        return 'error'
+    if dev['power']['disable_depth']:
+        return 'unsupported'
+    _RPM_STATUS_LOOKUP = [
+        "active",
+        "resuming",
+        "suspended",
+        "suspending"
+    ]
+    return _RPM_STATUS_LOOKUP[dev['power']['runtime_status']]
+
+
+class LxGenPDSummary(gdb.Command):
+    '''Print genpd summary
+
+Output is similar to /sys/kernel/debug/pm_genpd/pm_genpd_summary'''
+
+    def __init__(self):
+        super(LxGenPDSummary, self).__init__('lx-genpd-summary', gdb.COMMAND_DATA)
+
+    def summary_one(self, genpd):
+        if genpd['status'] == 0:
+            status_string = 'on'
+        else:
+            status_string = 'off-{}'.format(genpd['state_idx'])
+
+        slave_names = []
+        for link in list_for_each_entry(
+                genpd['master_links'],
+                device_link_type.get_type().pointer(),
+                'master_node'):
+            slave_names.apend(link['slave']['name'])
+
+        gdb.write('%-30s  %-15s %s\n' % (
+                genpd['name'].string(),
+                status_string,
+                ', '.join(slave_names)))
+
+        # Print devices in domain
+        for pm_data in list_for_each_entry(genpd['dev_list'],
+                        pm_domain_data_type.get_type().pointer(),
+                        'list_node'):
+            dev = pm_data['dev']
+            kobj_path = kobject_get_path(dev['kobj'])
+            gdb.write('    %-50s  %s\n' % (kobj_path, rtpm_status_str(dev)))
+
+    def invoke(self, arg, from_tty):
+        gdb.write('domain                          status          slaves\n');
+        gdb.write('    /device                                             runtime status\n');
+        gdb.write('----------------------------------------------------------------------\n');
+        for genpd in list_for_each_entry(
+                gdb.parse_and_eval('&gpd_list'),
+                generic_pm_domain_type.get_type().pointer(),
+                'gpd_list_node'):
+            self.summary_one(genpd)
+
+
+LxGenPDSummary()

scripts/gdb/vmlinux-gdb.py

···
     import linux.constants
     import linux.timerlist
     import linux.clk
+    import linux.genpd