x86/paravirt: add spin_lock_flags lock op
It is useful for a pv_lock_ops backend to know whether interrupts are
enabled or not in the context a spin_lock is being called. This
allows it to enable interrupts while spinning, which could be
particularly helpful when spinning becomes blocking.
The default implementation just calls the normal spin_lock op,
ignoring the flags.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/paravirt-spinlocks.c b/arch/x86/kernel/paravirt-spinlocks.c
index 38d7f7f..206359a 100644
--- a/arch/x86/kernel/paravirt-spinlocks.c
+++ b/arch/x86/kernel/paravirt-spinlocks.c
@@ -7,12 +7,18 @@
#include <asm/paravirt.h>
+static void default_spin_lock_flags(struct raw_spinlock *lock, unsigned long flags)
+{
+ __raw_spin_lock(lock);
+}
+
struct pv_lock_ops pv_lock_ops = {
#ifdef CONFIG_SMP
.spin_is_locked = __ticket_spin_is_locked,
.spin_is_contended = __ticket_spin_is_contended,
.spin_lock = __ticket_spin_lock,
+ .spin_lock_flags = default_spin_lock_flags,
.spin_trylock = __ticket_spin_trylock,
.spin_unlock = __ticket_spin_unlock,
#endif
diff --git a/include/asm-x86/paravirt.h b/include/asm-x86/paravirt.h
index db9b064..8e9b126 100644
--- a/include/asm-x86/paravirt.h
+++ b/include/asm-x86/paravirt.h
@@ -333,6 +333,7 @@
int (*spin_is_locked)(struct raw_spinlock *lock);
int (*spin_is_contended)(struct raw_spinlock *lock);
void (*spin_lock)(struct raw_spinlock *lock);
+ void (*spin_lock_flags)(struct raw_spinlock *lock, unsigned long flags);
int (*spin_trylock)(struct raw_spinlock *lock);
void (*spin_unlock)(struct raw_spinlock *lock);
};
@@ -1414,6 +1415,12 @@
PVOP_VCALL1(pv_lock_ops.spin_lock, lock);
}
+static __always_inline void __raw_spin_lock_flags(struct raw_spinlock *lock,
+ unsigned long flags)
+{
+ PVOP_VCALL2(pv_lock_ops.spin_lock_flags, lock, flags);
+}
+
static __always_inline int __raw_spin_trylock(struct raw_spinlock *lock)
{
return PVOP_CALL1(int, pv_lock_ops.spin_trylock, lock);
diff --git a/include/asm-x86/spinlock.h b/include/asm-x86/spinlock.h
index e39c790..b755ea8 100644
--- a/include/asm-x86/spinlock.h
+++ b/include/asm-x86/spinlock.h
@@ -182,8 +182,6 @@
}
#endif
-#define __raw_spin_lock_flags(lock, flags) __raw_spin_lock(lock)
-
#ifdef CONFIG_PARAVIRT
/*
* Define virtualization-friendly old-style lock byte lock, for use in
@@ -272,6 +270,13 @@
{
__ticket_spin_unlock(lock);
}
+
+static __always_inline void __raw_spin_lock_flags(raw_spinlock_t *lock,
+ unsigned long flags)
+{
+ __raw_spin_lock(lock);
+}
+
#endif /* CONFIG_PARAVIRT */
static inline void __raw_spin_unlock_wait(raw_spinlock_t *lock)
