ARM: hw_breakpoint: Debug powerdown support for self-hosted debug

[firefly-linux-kernel-4.4.55.git] / arch / arm / kernel / hw_breakpoint.c

diff --git a/arch/arm/kernel/hw_breakpoint.c b/arch/arm/kernel/hw_breakpoint.c
index 201d4406fe0d0c4feb60c4702b44475d2bba6e67..5eae53e7a2e1619c5d128b20b5337e727fc43864 100644 (file)
--- a/arch/arm/kernel/hw_breakpoint.c
+++ b/arch/arm/kernel/hw_breakpoint.c
@@ -28,6 +28,7 @@
 #include <linux/perf_event.h>
 #include <linux/hw_breakpoint.h>
 #include <linux/smp.h>
+#include <linux/cpu_pm.h>
 
 #include <asm/cacheflush.h>
 #include <asm/cputype.h>
@@ -1032,6 +1033,30 @@ static struct notifier_block __cpuinitdata dbg_reset_nb = {
        .notifier_call = dbg_reset_notify,
 };
 
+#ifdef CONFIG_CPU_PM
+static int dbg_cpu_pm_notify(struct notifier_block *self, unsigned long action,
+                            void *v)
+{
+       if (action == CPU_PM_EXIT)
+               reset_ctrl_regs(NULL);
+
+       return NOTIFY_OK;
+}
+
+static struct notifier_block __cpuinitdata dbg_cpu_pm_nb = {
+       .notifier_call = dbg_cpu_pm_notify,
+};
+
+static void __init pm_init(void)
+{
+       cpu_pm_register_notifier(&dbg_cpu_pm_nb);
+}
+#else
+static inline void pm_init(void)
+{
+}
+#endif
+
 static int __init arch_hw_breakpoint_init(void)
 {
        debug_arch = get_debug_arch();
@@ -1081,8 +1106,9 @@ static int __init arch_hw_breakpoint_init(void)
        hook_ifault_code(FAULT_CODE_DEBUG, hw_breakpoint_pending, SIGTRAP,
                        TRAP_HWBKPT, "breakpoint debug exception");
 
-       /* Register hotplug notifier. */
+       /* Register hotplug and PM notifiers. */
        register_cpu_notifier(&dbg_reset_nb);
+       pm_init();
        return 0;
 }
 arch_initcall(arch_hw_breakpoint_init);