[tip:perf/core] watchdog: Add watchdog enable/ disable all functions

[tip-bot for Stephane Eranian <tipbot@zytor.com>]

Commit-ID:  b3738d29323344da3017a91010530cf3a58590fc
Gitweb:     http://git.kernel.org/tip/b3738d29323344da3017a91010530cf3a58590fc
Author:     Stephane Eranian <eranian@google.com>
AuthorDate: Mon, 17 Nov 2014 20:07:03 +0100
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Thu, 2 Apr 2015 17:33:15 +0200

watchdog: Add watchdog enable/disable all functions

This patch adds two new functions to enable/disable
the watchdog across all CPUs.

This will be used by the HT PMU bug workaround code to
disable/enable the NMI watchdog across quirk enablement.

Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: bp@alien8.de
Cc: jolsa@redhat.com
Cc: kan.liang@intel.com
Cc: maria.n.dimakopoulou@gmail.com
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/1416251225-17721-12-git-send-email-eranian@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 include/linux/watchdog.h |  8 ++++++++
 kernel/watchdog.c        | 28 ++++++++++++++++++++++++++++
 2 files changed, 36 insertions(+)

diff --git a/include/linux/watchdog.h b/include/linux/watchdog.h
index 395b70e..a746bf5 100644
--- a/include/linux/watchdog.h
+++ b/include/linux/watchdog.h
@@ -137,4 +137,12 @@ extern int watchdog_init_timeout(struct watchdog_device *wdd,
 extern int watchdog_register_device(struct watchdog_device *);
 extern void watchdog_unregister_device(struct watchdog_device *);
 
+#ifdef CONFIG_HARDLOCKUP_DETECTOR
+void watchdog_nmi_disable_all(void);
+void watchdog_nmi_enable_all(void);
+#else
+static inline void watchdog_nmi_disable_all(void) {}
+static inline void watchdog_nmi_enable_all(void) {}
+#endif
+
 #endif  /* ifndef _LINUX_WATCHDOG_H */
diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 3174bf8..9a056f5 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -567,9 +567,37 @@ static void watchdog_nmi_disable(unsigned int cpu)
 		cpu0_err = 0;
 	}
 }
+
+void watchdog_nmi_enable_all(void)
+{
+	int cpu;
+
+	if (!watchdog_user_enabled)
+		return;
+
+	get_online_cpus();
+	for_each_online_cpu(cpu)
+		watchdog_nmi_enable(cpu);
+	put_online_cpus();
+}
+
+void watchdog_nmi_disable_all(void)
+{
+	int cpu;
+
+	if (!watchdog_running)
+		return;
+
+	get_online_cpus();
+	for_each_online_cpu(cpu)
+		watchdog_nmi_disable(cpu);
+	put_online_cpus();
+}
 #else
 static int watchdog_nmi_enable(unsigned int cpu) { return 0; }
 static void watchdog_nmi_disable(unsigned int cpu) { return; }
+void watchdog_nmi_enable_all(void) {}
+void watchdog_nmi_disable_all(void) {}
 #endif /* CONFIG_HARDLOCKUP_DETECTOR */
 
 static struct smp_hotplug_thread watchdog_threads = {