[PATCH] s390x/spinlock: Provide vcpu_is_preempted globally

From: Christian Borntraeger
Date: Thu Sep 29 2016 - 07:54:11 EST


this implements the s390 backend for commit
"kernel/sched: introduce vcpu preempted check interface"
by simply reusing the existing cpu_is_preempted function.

Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
---
Martin, Heiko,

this patch is a minimal change by not touching all existing users of
cpu_is_preempted in spinlock.c. If you want it differently, let me
know.


arch/s390/include/asm/spinlock.h | 7 +++++++
arch/s390/lib/spinlock.c | 3 ++-
2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/arch/s390/include/asm/spinlock.h b/arch/s390/include/asm/spinlock.h
index 63ebf37..6e82986 100644
--- a/arch/s390/include/asm/spinlock.h
+++ b/arch/s390/include/asm/spinlock.h
@@ -21,6 +21,13 @@ _raw_compare_and_swap(unsigned int *lock, unsigned int old, unsigned int new)
return __sync_bool_compare_and_swap(lock, old, new);
}

+int arch_vcpu_is_preempted(int cpu);
+#define vcpu_is_preempted cpu_is_preempted
+static inline bool cpu_is_preempted(int cpu)
+{
+ return arch_vcpu_is_preempted(cpu);
+}
+
/*
* Simple spin lock operations. There are two variants, one clears IRQ's
* on the local processor, one does not.
diff --git a/arch/s390/lib/spinlock.c b/arch/s390/lib/spinlock.c
index e5f50a7..9f473c8 100644
--- a/arch/s390/lib/spinlock.c
+++ b/arch/s390/lib/spinlock.c
@@ -37,7 +37,7 @@ static inline void _raw_compare_and_delay(unsigned int *lock, unsigned int old)
asm(".insn rsy,0xeb0000000022,%0,0,%1" : : "d" (old), "Q" (*lock));
}

-static inline int cpu_is_preempted(int cpu)
+int arch_vcpu_is_preempted(int cpu)
{
if (test_cpu_flag_of(CIF_ENABLED_WAIT, cpu))
return 0;
@@ -45,6 +45,7 @@ static inline int cpu_is_preempted(int cpu)
return 0;
return 1;
}
+EXPORT_SYMBOL(arch_vcpu_is_preempted);

void arch_spin_lock_wait(arch_spinlock_t *lp)
{
--
2.5.5