[tip:locking/core] clocksource/arm_arch_timer: Use static_branch_enable_cpuslocked()

[tip-bot for Marc Zyngier]

Commit-ID:  450f9689f294c331c56ec37d68302ccc19c7caa2
Gitweb: http://git.kernel.org/tip/450f9689f294c331c56ec37d68302ccc19c7caa2
Author: Marc Zyngier 
AuthorDate: Tue, 1 Aug 2017 09:02:57 +0100
Committer:  Ingo Molnar 
CommitDate: Thu, 10 Aug 2017 12:29:00 +0200

clocksource/arm_arch_timer: Use static_branch_enable_cpuslocked()

Use the new static_branch_enable_cpuslocked() function to switch
the workaround static key on the CPU hotplug path.

Signed-off-by: Marc Zyngier 
Signed-off-by: Peter Zijlstra (Intel) 
Cc: Leo Yan 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-arm-ker...@lists.infradead.org
Link: http://lkml.kernel.org/r/20170801080257.5056-5-marc.zyng...@arm.com
Signed-off-by: Ingo Molnar 
---
 drivers/clocksource/arm_arch_timer.c | 6 +-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/clocksource/arm_arch_timer.c 
b/drivers/clocksource/arm_arch_timer.c
index aae87c4..c62e716 100644
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -455,7 +455,11 @@ void arch_timer_enable_workaround(const struct 
arch_timer_erratum_workaround *wa
per_cpu(timer_unstable_counter_workaround, i) = wa;
}
 
-   static_branch_enable(_timer_read_ool_enabled);
+   /*
+* Use the locked version, as we're called from the CPU
+* hotplug framework. Otherwise, we end-up in deadlock-land.
+*/
+   static_branch_enable_cpuslocked(_timer_read_ool_enabled);
 
/*
 * Don't use the vdso fastpath if errata require using the

[tip:locking/core] clocksource/arm_arch_timer: Use static_branch_enable_cpuslocked()

[tip-bot for Marc Zyngier]

Commit-ID:  450f9689f294c331c56ec37d68302ccc19c7caa2
Gitweb: http://git.kernel.org/tip/450f9689f294c331c56ec37d68302ccc19c7caa2
Author: Marc Zyngier 
AuthorDate: Tue, 1 Aug 2017 09:02:57 +0100
Committer:  Ingo Molnar 
CommitDate: Thu, 10 Aug 2017 12:29:00 +0200

clocksource/arm_arch_timer: Use static_branch_enable_cpuslocked()

Use the new static_branch_enable_cpuslocked() function to switch
the workaround static key on the CPU hotplug path.

Signed-off-by: Marc Zyngier 
Signed-off-by: Peter Zijlstra (Intel) 
Cc: Leo Yan 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-arm-ker...@lists.infradead.org
Link: http://lkml.kernel.org/r/20170801080257.5056-5-marc.zyng...@arm.com
Signed-off-by: Ingo Molnar 
---
 drivers/clocksource/arm_arch_timer.c | 6 +-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/clocksource/arm_arch_timer.c 
b/drivers/clocksource/arm_arch_timer.c
index aae87c4..c62e716 100644
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -455,7 +455,11 @@ void arch_timer_enable_workaround(const struct 
arch_timer_erratum_workaround *wa
per_cpu(timer_unstable_counter_workaround, i) = wa;
}
 
-   static_branch_enable(_timer_read_ool_enabled);
+   /*
+* Use the locked version, as we're called from the CPU
+* hotplug framework. Otherwise, we end-up in deadlock-land.
+*/
+   static_branch_enable_cpuslocked(_timer_read_ool_enabled);
 
/*
 * Don't use the vdso fastpath if errata require using the