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-rw-r--r--arch/s390/include/asm/spinlock.h98
-rw-r--r--arch/s390/include/asm/spinlock_types.h6
-rw-r--r--arch/s390/lib/spinlock.c55
3 files changed, 82 insertions, 77 deletions
diff --git a/arch/s390/include/asm/spinlock.h b/arch/s390/include/asm/spinlock.h
index 83e5d216105e..b60212a02d08 100644
--- a/arch/s390/include/asm/spinlock.h
+++ b/arch/s390/include/asm/spinlock.h
@@ -14,15 +14,16 @@
extern int spin_retry;
static inline int
-_raw_compare_and_swap(volatile unsigned int *lock,
- unsigned int old, unsigned int new)
+_raw_compare_and_swap(unsigned int *lock, unsigned int old, unsigned int new)
{
+ unsigned int old_expected = old;
+
asm volatile(
" cs %0,%3,%1"
: "=d" (old), "=Q" (*lock)
: "0" (old), "d" (new), "Q" (*lock)
: "cc", "memory" );
- return old;
+ return old == old_expected;
}
/*
@@ -34,57 +35,66 @@ _raw_compare_and_swap(volatile unsigned int *lock,
* (the type definitions are in asm/spinlock_types.h)
*/
-#define arch_spin_is_locked(x) ((x)->owner_cpu != 0)
-#define arch_spin_unlock_wait(lock) \
- do { while (arch_spin_is_locked(lock)) \
- arch_spin_relax(lock); } while (0)
-
-extern void arch_spin_lock_wait(arch_spinlock_t *);
-extern void arch_spin_lock_wait_flags(arch_spinlock_t *, unsigned long flags);
-extern int arch_spin_trylock_retry(arch_spinlock_t *);
-extern void arch_spin_relax(arch_spinlock_t *lock);
+void arch_spin_lock_wait(arch_spinlock_t *);
+int arch_spin_trylock_retry(arch_spinlock_t *);
+void arch_spin_relax(arch_spinlock_t *);
+void arch_spin_lock_wait_flags(arch_spinlock_t *, unsigned long flags);
static inline int arch_spin_value_unlocked(arch_spinlock_t lock)
{
- return lock.owner_cpu == 0;
+ return lock.lock == 0;
}
-static inline void arch_spin_lock(arch_spinlock_t *lp)
+static inline int arch_spin_is_locked(arch_spinlock_t *lp)
+{
+ return ACCESS_ONCE(lp->lock) != 0;
+}
+
+static inline int arch_spin_trylock_once(arch_spinlock_t *lp)
{
- int old;
+ unsigned int new = ~smp_processor_id();
- old = _raw_compare_and_swap(&lp->owner_cpu, 0, ~smp_processor_id());
- if (likely(old == 0))
- return;
- arch_spin_lock_wait(lp);
+ return _raw_compare_and_swap(&lp->lock, 0, new);
}
-static inline void arch_spin_lock_flags(arch_spinlock_t *lp,
- unsigned long flags)
+static inline int arch_spin_tryrelease_once(arch_spinlock_t *lp)
{
- int old;
+ unsigned int old = ~smp_processor_id();
- old = _raw_compare_and_swap(&lp->owner_cpu, 0, ~smp_processor_id());
- if (likely(old == 0))
- return;
- arch_spin_lock_wait_flags(lp, flags);
+ return _raw_compare_and_swap(&lp->lock, old, 0);
}
-static inline int arch_spin_trylock(arch_spinlock_t *lp)
+static inline void arch_spin_lock(arch_spinlock_t *lp)
{
- int old;
+ if (unlikely(!arch_spin_trylock_once(lp)))
+ arch_spin_lock_wait(lp);
+}
- old = _raw_compare_and_swap(&lp->owner_cpu, 0, ~smp_processor_id());
- if (likely(old == 0))
- return 1;
- return arch_spin_trylock_retry(lp);
+static inline void arch_spin_lock_flags(arch_spinlock_t *lp,
+ unsigned long flags)
+{
+ if (unlikely(!arch_spin_trylock_once(lp)))
+ arch_spin_lock_wait_flags(lp, flags);
+}
+
+static inline int arch_spin_trylock(arch_spinlock_t *lp)
+{
+ if (unlikely(!arch_spin_trylock_once(lp)))
+ return arch_spin_trylock_retry(lp);
+ return 1;
}
static inline void arch_spin_unlock(arch_spinlock_t *lp)
{
- _raw_compare_and_swap(&lp->owner_cpu, lp->owner_cpu, 0);
+ arch_spin_tryrelease_once(lp);
}
-
+
+static inline void arch_spin_unlock_wait(arch_spinlock_t *lock)
+{
+ while (arch_spin_is_locked(lock))
+ arch_spin_relax(lock);
+}
+
/*
* Read-write spinlocks, allowing multiple readers
* but only one writer.
@@ -119,7 +129,7 @@ static inline void arch_read_lock(arch_rwlock_t *rw)
{
unsigned int old;
old = rw->lock & 0x7fffffffU;
- if (_raw_compare_and_swap(&rw->lock, old, old + 1) != old)
+ if (!_raw_compare_and_swap(&rw->lock, old, old + 1))
_raw_read_lock_wait(rw);
}
@@ -127,30 +137,28 @@ static inline void arch_read_lock_flags(arch_rwlock_t *rw, unsigned long flags)
{
unsigned int old;
old = rw->lock & 0x7fffffffU;
- if (_raw_compare_and_swap(&rw->lock, old, old + 1) != old)
+ if (!_raw_compare_and_swap(&rw->lock, old, old + 1))
_raw_read_lock_wait_flags(rw, flags);
}
static inline void arch_read_unlock(arch_rwlock_t *rw)
{
- unsigned int old, cmp;
+ unsigned int old;
- old = rw->lock;
do {
- cmp = old;
- old = _raw_compare_and_swap(&rw->lock, old, old - 1);
- } while (cmp != old);
+ old = ACCESS_ONCE(rw->lock);
+ } while (!_raw_compare_and_swap(&rw->lock, old, old - 1));
}
static inline void arch_write_lock(arch_rwlock_t *rw)
{
- if (unlikely(_raw_compare_and_swap(&rw->lock, 0, 0x80000000) != 0))
+ if (unlikely(!_raw_compare_and_swap(&rw->lock, 0, 0x80000000)))
_raw_write_lock_wait(rw);
}
static inline void arch_write_lock_flags(arch_rwlock_t *rw, unsigned long flags)
{
- if (unlikely(_raw_compare_and_swap(&rw->lock, 0, 0x80000000) != 0))
+ if (unlikely(!_raw_compare_and_swap(&rw->lock, 0, 0x80000000)))
_raw_write_lock_wait_flags(rw, flags);
}
@@ -163,14 +171,14 @@ static inline int arch_read_trylock(arch_rwlock_t *rw)
{
unsigned int old;
old = rw->lock & 0x7fffffffU;
- if (likely(_raw_compare_and_swap(&rw->lock, old, old + 1) == old))
+ if (likely(_raw_compare_and_swap(&rw->lock, old, old + 1)))
return 1;
return _raw_read_trylock_retry(rw);
}
static inline int arch_write_trylock(arch_rwlock_t *rw)
{
- if (likely(_raw_compare_and_swap(&rw->lock, 0, 0x80000000) == 0))
+ if (likely(_raw_compare_and_swap(&rw->lock, 0, 0x80000000)))
return 1;
return _raw_write_trylock_retry(rw);
}
diff --git a/arch/s390/include/asm/spinlock_types.h b/arch/s390/include/asm/spinlock_types.h
index 9c76656a0af0..b2cd6ff7c2c5 100644
--- a/arch/s390/include/asm/spinlock_types.h
+++ b/arch/s390/include/asm/spinlock_types.h
@@ -6,13 +6,13 @@
#endif
typedef struct {
- volatile unsigned int owner_cpu;
+ unsigned int lock;
} __attribute__ ((aligned (4))) arch_spinlock_t;
-#define __ARCH_SPIN_LOCK_UNLOCKED { 0 }
+#define __ARCH_SPIN_LOCK_UNLOCKED { .lock = 0, }
typedef struct {
- volatile unsigned int lock;
+ unsigned int lock;
} arch_rwlock_t;
#define __ARCH_RW_LOCK_UNLOCKED { 0 }
diff --git a/arch/s390/lib/spinlock.c b/arch/s390/lib/spinlock.c
index f709983f41f8..4a3b33b2dbb9 100644
--- a/arch/s390/lib/spinlock.c
+++ b/arch/s390/lib/spinlock.c
@@ -31,22 +31,21 @@ void arch_spin_lock_wait(arch_spinlock_t *lp)
unsigned int owner;
while (1) {
- owner = lp->owner_cpu;
+ owner = lp->lock;
if (!owner || smp_vcpu_scheduled(~owner)) {
for (count = spin_retry; count > 0; count--) {
if (arch_spin_is_locked(lp))
continue;
- if (_raw_compare_and_swap(&lp->owner_cpu, 0,
- cpu) == 0)
+ if (_raw_compare_and_swap(&lp->lock, 0, cpu))
return;
}
if (MACHINE_IS_LPAR)
continue;
}
- owner = lp->owner_cpu;
+ owner = lp->lock;
if (owner)
smp_yield_cpu(~owner);
- if (_raw_compare_and_swap(&lp->owner_cpu, 0, cpu) == 0)
+ if (_raw_compare_and_swap(&lp->lock, 0, cpu))
return;
}
}
@@ -60,57 +59,55 @@ void arch_spin_lock_wait_flags(arch_spinlock_t *lp, unsigned long flags)
local_irq_restore(flags);
while (1) {
- owner = lp->owner_cpu;
+ owner = lp->lock;
if (!owner || smp_vcpu_scheduled(~owner)) {
for (count = spin_retry; count > 0; count--) {
if (arch_spin_is_locked(lp))
continue;
local_irq_disable();
- if (_raw_compare_and_swap(&lp->owner_cpu, 0,
- cpu) == 0)
+ if (_raw_compare_and_swap(&lp->lock, 0, cpu))
return;
local_irq_restore(flags);
}
if (MACHINE_IS_LPAR)
continue;
}
- owner = lp->owner_cpu;
+ owner = lp->lock;
if (owner)
smp_yield_cpu(~owner);
local_irq_disable();
- if (_raw_compare_and_swap(&lp->owner_cpu, 0, cpu) == 0)
+ if (_raw_compare_and_swap(&lp->lock, 0, cpu))
return;
local_irq_restore(flags);
}
}
EXPORT_SYMBOL(arch_spin_lock_wait_flags);
+void arch_spin_relax(arch_spinlock_t *lp)
+{
+ unsigned int cpu = lp->lock;
+ if (cpu != 0) {
+ if (MACHINE_IS_VM || MACHINE_IS_KVM ||
+ !smp_vcpu_scheduled(~cpu))
+ smp_yield_cpu(~cpu);
+ }
+}
+EXPORT_SYMBOL(arch_spin_relax);
+
int arch_spin_trylock_retry(arch_spinlock_t *lp)
{
- unsigned int cpu = ~smp_processor_id();
int count;
for (count = spin_retry; count > 0; count--) {
if (arch_spin_is_locked(lp))
continue;
- if (_raw_compare_and_swap(&lp->owner_cpu, 0, cpu) == 0)
+ if (arch_spin_trylock_once(lp))
return 1;
}
return 0;
}
EXPORT_SYMBOL(arch_spin_trylock_retry);
-void arch_spin_relax(arch_spinlock_t *lock)
-{
- unsigned int cpu = lock->owner_cpu;
- if (cpu != 0) {
- if (MACHINE_IS_VM || MACHINE_IS_KVM ||
- !smp_vcpu_scheduled(~cpu))
- smp_yield_cpu(~cpu);
- }
-}
-EXPORT_SYMBOL(arch_spin_relax);
-
void _raw_read_lock_wait(arch_rwlock_t *rw)
{
unsigned int old;
@@ -124,7 +121,7 @@ void _raw_read_lock_wait(arch_rwlock_t *rw)
if (!arch_read_can_lock(rw))
continue;
old = rw->lock & 0x7fffffffU;
- if (_raw_compare_and_swap(&rw->lock, old, old + 1) == old)
+ if (_raw_compare_and_swap(&rw->lock, old, old + 1))
return;
}
}
@@ -145,7 +142,7 @@ void _raw_read_lock_wait_flags(arch_rwlock_t *rw, unsigned long flags)
continue;
old = rw->lock & 0x7fffffffU;
local_irq_disable();
- if (_raw_compare_and_swap(&rw->lock, old, old + 1) == old)
+ if (_raw_compare_and_swap(&rw->lock, old, old + 1))
return;
}
}
@@ -160,7 +157,7 @@ int _raw_read_trylock_retry(arch_rwlock_t *rw)
if (!arch_read_can_lock(rw))
continue;
old = rw->lock & 0x7fffffffU;
- if (_raw_compare_and_swap(&rw->lock, old, old + 1) == old)
+ if (_raw_compare_and_swap(&rw->lock, old, old + 1))
return 1;
}
return 0;
@@ -178,7 +175,7 @@ void _raw_write_lock_wait(arch_rwlock_t *rw)
}
if (!arch_write_can_lock(rw))
continue;
- if (_raw_compare_and_swap(&rw->lock, 0, 0x80000000) == 0)
+ if (_raw_compare_and_swap(&rw->lock, 0, 0x80000000))
return;
}
}
@@ -197,7 +194,7 @@ void _raw_write_lock_wait_flags(arch_rwlock_t *rw, unsigned long flags)
if (!arch_write_can_lock(rw))
continue;
local_irq_disable();
- if (_raw_compare_and_swap(&rw->lock, 0, 0x80000000) == 0)
+ if (_raw_compare_and_swap(&rw->lock, 0, 0x80000000))
return;
}
}
@@ -210,7 +207,7 @@ int _raw_write_trylock_retry(arch_rwlock_t *rw)
while (count-- > 0) {
if (!arch_write_can_lock(rw))
continue;
- if (_raw_compare_and_swap(&rw->lock, 0, 0x80000000) == 0)
+ if (_raw_compare_and_swap(&rw->lock, 0, 0x80000000))
return 1;
}
return 0;
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-20 00:22:04 +0000