#undef __ATOMIC_OPS
#undef __ATOMIC_OP
-static inline void __atomic_add_const(int val, int *ptr)
-{
- asm volatile(
- " asi %[ptr],%[val]\n"
- : [ptr] "+Q" (*ptr) : [val] "i" (val) : "cc");
+#define __ATOMIC_CONST_OP(op_name, op_type, op_string, op_barrier) \
+static inline void op_name(op_type val, op_type *ptr) \
+{ \
+ asm volatile( \
+ op_string " %[ptr],%[val]\n" \
+ op_barrier \
+ : [ptr] "+Q" (*ptr) : [val] "i" (val) : "cc", "memory");\
}
-static inline void __atomic64_add_const(long val, long *ptr)
-{
- asm volatile(
- " agsi %[ptr],%[val]\n"
- : [ptr] "+Q" (*ptr) : [val] "i" (val) : "cc");
-}
+#define __ATOMIC_CONST_OPS(op_name, op_type, op_string) \
+ __ATOMIC_CONST_OP(op_name, op_type, op_string, "\n") \
+ __ATOMIC_CONST_OP(op_name##_barrier, op_type, op_string, "bcr 14,0\n")
+
+__ATOMIC_CONST_OPS(__atomic_add_const, int, "asi")
+__ATOMIC_CONST_OPS(__atomic64_add_const, long, "agsi")
+
+#undef __ATOMIC_CONST_OPS
+#undef __ATOMIC_CONST_OP
#else /* CONFIG_HAVE_MARCH_Z196_FEATURES */
#undef __ATOMIC64_OPS
+#define __atomic_add_const(val, ptr) __atomic_add(val, ptr)
+#define __atomic_add_const_barrier(val, ptr) __atomic_add(val, ptr)
+#define __atomic64_add_const(val, ptr) __atomic64_add(val, ptr)
+#define __atomic64_add_const_barrier(val, ptr) __atomic64_add(val, ptr)
+
#endif /* CONFIG_HAVE_MARCH_Z196_FEATURES */
static inline int __atomic_cmpxchg(int *ptr, int old, int new)
* (the type definitions are in asm/spinlock_types.h)
*/
-void arch_lock_relax(int cpu);
void arch_spin_relax(arch_spinlock_t *lock);
void arch_spin_lock_wait(arch_spinlock_t *);
* read_can_lock - would read_trylock() succeed?
* @lock: the rwlock in question.
*/
-#define arch_read_can_lock(x) ((int)(x)->lock >= 0)
+#define arch_read_can_lock(x) (((x)->cnts & 0xffff0000) == 0)
/**
* write_can_lock - would write_trylock() succeed?
* @lock: the rwlock in question.
*/
-#define arch_write_can_lock(x) ((x)->lock == 0)
-
-extern int _raw_read_trylock_retry(arch_rwlock_t *lp);
-extern int _raw_write_trylock_retry(arch_rwlock_t *lp);
+#define arch_write_can_lock(x) ((x)->cnts == 0)
#define arch_read_lock_flags(lock, flags) arch_read_lock(lock)
#define arch_write_lock_flags(lock, flags) arch_write_lock(lock)
+#define arch_read_relax(rw) barrier()
+#define arch_write_relax(rw) barrier()
-static inline int arch_read_trylock_once(arch_rwlock_t *rw)
-{
- int old = ACCESS_ONCE(rw->lock);
- return likely(old >= 0 &&
- __atomic_cmpxchg_bool(&rw->lock, old, old + 1));
-}
-
-static inline int arch_write_trylock_once(arch_rwlock_t *rw)
-{
- int old = ACCESS_ONCE(rw->lock);
- return likely(old == 0 &&
- __atomic_cmpxchg_bool(&rw->lock, 0, 0x80000000));
-}
-
-#ifdef CONFIG_HAVE_MARCH_Z196_FEATURES
-
-#define __RAW_OP_OR "lao"
-#define __RAW_OP_AND "lan"
-#define __RAW_OP_ADD "laa"
-
-#define __RAW_LOCK(ptr, op_val, op_string) \
-({ \
- int old_val; \
- \
- typecheck(int *, ptr); \
- asm volatile( \
- op_string " %0,%2,%1\n" \
- "bcr 14,0\n" \
- : "=d" (old_val), "+Q" (*ptr) \
- : "d" (op_val) \
- : "cc", "memory"); \
- old_val; \
-})
-
-#define __RAW_UNLOCK(ptr, op_val, op_string) \
-({ \
- int old_val; \
- \
- typecheck(int *, ptr); \
- asm volatile( \
- op_string " %0,%2,%1\n" \
- : "=d" (old_val), "+Q" (*ptr) \
- : "d" (op_val) \
- : "cc", "memory"); \
- old_val; \
-})
-
-extern void _raw_read_lock_wait(arch_rwlock_t *lp);
-extern void _raw_write_lock_wait(arch_rwlock_t *lp, int prev);
+void arch_read_lock_wait(arch_rwlock_t *lp);
+void arch_write_lock_wait(arch_rwlock_t *lp);
static inline void arch_read_lock(arch_rwlock_t *rw)
{
int old;
- old = __RAW_LOCK(&rw->lock, 1, __RAW_OP_ADD);
- if (old < 0)
- _raw_read_lock_wait(rw);
+ old = __atomic_add(1, &rw->cnts);
+ if (old & 0xffff0000)
+ arch_read_lock_wait(rw);
}
static inline void arch_read_unlock(arch_rwlock_t *rw)
{
- __RAW_UNLOCK(&rw->lock, -1, __RAW_OP_ADD);
+ __atomic_add_const_barrier(-1, &rw->cnts);
}
static inline void arch_write_lock(arch_rwlock_t *rw)
{
- int old;
-
- old = __RAW_LOCK(&rw->lock, 0x80000000, __RAW_OP_OR);
- if (old != 0)
- _raw_write_lock_wait(rw, old);
- rw->owner = SPINLOCK_LOCKVAL;
+ if (!__atomic_cmpxchg_bool(&rw->cnts, 0, 0x30000))
+ arch_write_lock_wait(rw);
}
static inline void arch_write_unlock(arch_rwlock_t *rw)
{
- rw->owner = 0;
- __RAW_UNLOCK(&rw->lock, 0x7fffffff, __RAW_OP_AND);
+ __atomic_add_barrier(-0x30000, &rw->cnts);
}
-#else /* CONFIG_HAVE_MARCH_Z196_FEATURES */
-
-extern void _raw_read_lock_wait(arch_rwlock_t *lp);
-extern void _raw_write_lock_wait(arch_rwlock_t *lp);
-static inline void arch_read_lock(arch_rwlock_t *rw)
-{
- if (!arch_read_trylock_once(rw))
- _raw_read_lock_wait(rw);
-}
-
-static inline void arch_read_unlock(arch_rwlock_t *rw)
+static inline int arch_read_trylock(arch_rwlock_t *rw)
{
int old;
- do {
- old = ACCESS_ONCE(rw->lock);
- } while (!__atomic_cmpxchg_bool(&rw->lock, old, old - 1));
-}
-
-static inline void arch_write_lock(arch_rwlock_t *rw)
-{
- if (!arch_write_trylock_once(rw))
- _raw_write_lock_wait(rw);
- rw->owner = SPINLOCK_LOCKVAL;
-}
-
-static inline void arch_write_unlock(arch_rwlock_t *rw)
-{
- typecheck(int, rw->lock);
-
- rw->owner = 0;
- asm volatile(
- "st %1,%0\n"
- : "+Q" (rw->lock)
- : "d" (0)
- : "cc", "memory");
-}
-
-#endif /* CONFIG_HAVE_MARCH_Z196_FEATURES */
-
-static inline int arch_read_trylock(arch_rwlock_t *rw)
-{
- if (!arch_read_trylock_once(rw))
- return _raw_read_trylock_retry(rw);
- return 1;
+ old = READ_ONCE(rw->cnts);
+ return (!(old & 0xffff0000) &&
+ __atomic_cmpxchg_bool(&rw->cnts, old, old + 1));
}
static inline int arch_write_trylock(arch_rwlock_t *rw)
{
- if (!arch_write_trylock_once(rw) && !_raw_write_trylock_retry(rw))
- return 0;
- rw->owner = SPINLOCK_LOCKVAL;
- return 1;
-}
-
-static inline void arch_read_relax(arch_rwlock_t *rw)
-{
- arch_lock_relax(rw->owner);
-}
+ int old;
-static inline void arch_write_relax(arch_rwlock_t *rw)
-{
- arch_lock_relax(rw->owner);
+ old = READ_ONCE(rw->cnts);
+ return !old && __atomic_cmpxchg_bool(&rw->cnts, 0, 0x30000);
}
#endif /* __ASM_SPINLOCK_H */
#define __ARCH_SPIN_LOCK_UNLOCKED { .lock = 0, }
typedef struct {
- int lock;
- int owner;
+ int cnts;
+ arch_spinlock_t wait;
} arch_rwlock_t;
#define __ARCH_RW_LOCK_UNLOCKED { 0 }
}
EXPORT_SYMBOL(arch_spin_trylock_retry);
-void _raw_read_lock_wait(arch_rwlock_t *rw)
+void arch_read_lock_wait(arch_rwlock_t *rw)
{
- int count = spin_retry;
- int owner, old;
-
-#ifdef CONFIG_HAVE_MARCH_Z196_FEATURES
- __RAW_LOCK(&rw->lock, -1, __RAW_OP_ADD);
-#endif
- owner = 0;
- while (1) {
- if (count-- <= 0) {
- if (owner && arch_vcpu_is_preempted(owner - 1))
- smp_yield_cpu(owner - 1);
- count = spin_retry;
- }
- old = ACCESS_ONCE(rw->lock);
- owner = ACCESS_ONCE(rw->owner);
- if (old < 0)
- continue;
- if (__atomic_cmpxchg_bool(&rw->lock, old, old + 1))
- return;
+ if (unlikely(in_interrupt())) {
+ while (READ_ONCE(rw->cnts) & 0x10000)
+ barrier();
+ return;
}
-}
-EXPORT_SYMBOL(_raw_read_lock_wait);
-
-int _raw_read_trylock_retry(arch_rwlock_t *rw)
-{
- int count = spin_retry;
- int old;
- while (count-- > 0) {
- old = ACCESS_ONCE(rw->lock);
- if (old < 0)
- continue;
- if (__atomic_cmpxchg_bool(&rw->lock, old, old + 1))
- return 1;
- }
- return 0;
+ /* Remove this reader again to allow recursive read locking */
+ __atomic_add_const(-1, &rw->cnts);
+ /* Put the reader into the wait queue */
+ arch_spin_lock(&rw->wait);
+ /* Now add this reader to the count value again */
+ __atomic_add_const(1, &rw->cnts);
+ /* Loop until the writer is done */
+ while (READ_ONCE(rw->cnts) & 0x10000)
+ barrier();
+ arch_spin_unlock(&rw->wait);
}
-EXPORT_SYMBOL(_raw_read_trylock_retry);
+EXPORT_SYMBOL(arch_read_lock_wait);
-#ifdef CONFIG_HAVE_MARCH_Z196_FEATURES
-
-void _raw_write_lock_wait(arch_rwlock_t *rw, int prev)
+void arch_write_lock_wait(arch_rwlock_t *rw)
{
- int count = spin_retry;
- int owner, old;
-
- owner = 0;
- while (1) {
- if (count-- <= 0) {
- if (owner && arch_vcpu_is_preempted(owner - 1))
- smp_yield_cpu(owner - 1);
- count = spin_retry;
- }
- old = ACCESS_ONCE(rw->lock);
- owner = ACCESS_ONCE(rw->owner);
- smp_mb();
- if (old >= 0) {
- prev = __RAW_LOCK(&rw->lock, 0x80000000, __RAW_OP_OR);
- old = prev;
- }
- if ((old & 0x7fffffff) == 0 && prev >= 0)
- break;
- }
-}
-EXPORT_SYMBOL(_raw_write_lock_wait);
+ int old;
-#else /* CONFIG_HAVE_MARCH_Z196_FEATURES */
+ /* Add this CPU to the write waiters */
+ __atomic_add(0x20000, &rw->cnts);
-void _raw_write_lock_wait(arch_rwlock_t *rw)
-{
- int count = spin_retry;
- int owner, old, prev;
+ /* Put the writer into the wait queue */
+ arch_spin_lock(&rw->wait);
- prev = 0x80000000;
- owner = 0;
while (1) {
- if (count-- <= 0) {
- if (owner && arch_vcpu_is_preempted(owner - 1))
- smp_yield_cpu(owner - 1);
- count = spin_retry;
- }
- old = ACCESS_ONCE(rw->lock);
- owner = ACCESS_ONCE(rw->owner);
- if (old >= 0 &&
- __atomic_cmpxchg_bool(&rw->lock, old, old | 0x80000000))
- prev = old;
- else
- smp_mb();
- if ((old & 0x7fffffff) == 0 && prev >= 0)
+ old = READ_ONCE(rw->cnts);
+ if ((old & 0x1ffff) == 0 &&
+ __atomic_cmpxchg_bool(&rw->cnts, old, old | 0x10000))
+ /* Got the lock */
break;
+ barrier();
}
-}
-EXPORT_SYMBOL(_raw_write_lock_wait);
-
-#endif /* CONFIG_HAVE_MARCH_Z196_FEATURES */
-
-int _raw_write_trylock_retry(arch_rwlock_t *rw)
-{
- int count = spin_retry;
- int old;
-
- while (count-- > 0) {
- old = ACCESS_ONCE(rw->lock);
- if (old)
- continue;
- if (__atomic_cmpxchg_bool(&rw->lock, 0, 0x80000000))
- return 1;
- }
- return 0;
-}
-EXPORT_SYMBOL(_raw_write_trylock_retry);
-void arch_lock_relax(int cpu)
-{
- if (!cpu)
- return;
- if (MACHINE_IS_LPAR && !arch_vcpu_is_preempted(cpu - 1))
- return;
- smp_yield_cpu(cpu - 1);
+ arch_spin_unlock(&rw->wait);
}
-EXPORT_SYMBOL(arch_lock_relax);
+EXPORT_SYMBOL(arch_write_lock_wait);
void arch_spin_relax(arch_spinlock_t *lp)
{
projects / mirror_ubuntu-bionic-kernel.git / commitdiff