linux-kernel - [PATCH 4/4] watchdog: use suspend/resume interface in fixup_ht

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Date:	Sat,  1 Aug 2015 14:49:25 +0200
From:	Ulrich Obergfell <uobergfe@...hat.com>
To:	linux-kernel@...r.kernel.org
Cc:	akpm@...ux-foundation.org, dzickus@...hat.com, atomlin@...hat.com,
	uobergfe@...hat.com, jolsa@...nel.org, mhocko@...e.cz,
	eranian@...gle.com, cmetcalf@...hip.com, fweisbec@...il.com
Subject: [PATCH 4/4] watchdog: use suspend/resume interface in fixup_ht_bug()

Remove watchdog_nmi_disable_all() and watchdog_nmi_enable_all()
since these functions are no longer needed. If a subsystem has a
need to deactivate the watchdog temporarily, it should utilize the
watchdog_suspend() and watchdog_resume() functions.

Signed-off-by: Ulrich Obergfell <uobergfe@...hat.com>
---
 arch/x86/kernel/cpu/perf_event_intel.c |  9 +++++---
 include/linux/watchdog.h               |  8 -------
 kernel/watchdog.c                      | 38 ----------------------------------
 3 files changed, 6 insertions(+), 49 deletions(-)

diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c
index b9826a9..d4e1b0c 100644
--- a/arch/x86/kernel/cpu/perf_event_intel.c
+++ b/arch/x86/kernel/cpu/perf_event_intel.c
@@ -12,7 +12,7 @@
 #include <linux/init.h>
 #include <linux/slab.h>
 #include <linux/export.h>
-#include <linux/watchdog.h>
+#include <linux/nmi.h>
 
 #include <asm/cpufeature.h>
 #include <asm/hardirq.h>
@@ -3368,7 +3368,10 @@ static __init int fixup_ht_bug(void)
 		return 0;
 	}
 
-	watchdog_nmi_disable_all();
+	if (watchdog_suspend() != 0) {
+		pr_info("failed to disable PMU erratum BJ122, BV98, HSD29 workaround\n");
+		return 0;
+	}
 
 	x86_pmu.flags &= ~(PMU_FL_EXCL_CNTRS | PMU_FL_EXCL_ENABLED);
 
@@ -3376,7 +3379,7 @@ static __init int fixup_ht_bug(void)
 	x86_pmu.commit_scheduling = NULL;
 	x86_pmu.stop_scheduling = NULL;
 
-	watchdog_nmi_enable_all();
+	watchdog_resume();
 
 	get_online_cpus();
 
diff --git a/include/linux/watchdog.h b/include/linux/watchdog.h
index f47fead..d74a0e9 100644
--- a/include/linux/watchdog.h
+++ b/include/linux/watchdog.h
@@ -140,12 +140,4 @@ 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 3618e93..bf751ef 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -614,47 +614,9 @@ static void watchdog_nmi_disable(unsigned int cpu)
 		cpu0_err = 0;
 	}
 }
-
-void watchdog_nmi_enable_all(void)
-{
-	int cpu;
-
-	mutex_lock(&watchdog_proc_mutex);
-
-	if (!(watchdog_enabled & NMI_WATCHDOG_ENABLED))
-		goto unlock;
-
-	get_online_cpus();
-	for_each_watchdog_cpu(cpu)
-		watchdog_nmi_enable(cpu);
-	put_online_cpus();
-
-unlock:
-	mutex_unlock(&watchdog_proc_mutex);
-}
-
-void watchdog_nmi_disable_all(void)
-{
-	int cpu;
-
-	mutex_lock(&watchdog_proc_mutex);
-
-	if (!watchdog_running)
-		goto unlock;
-
-	get_online_cpus();
-	for_each_watchdog_cpu(cpu)
-		watchdog_nmi_disable(cpu);
-	put_online_cpus();
-
-unlock:
-	mutex_unlock(&watchdog_proc_mutex);
-}
 #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 = {
-- 
1.7.11.7

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