diff options
Diffstat (limited to 'arch/s390/lib/spinlock.c')
-rw-r--r-- | arch/s390/lib/spinlock.c | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/arch/s390/lib/spinlock.c b/arch/s390/lib/spinlock.c new file mode 100644 index 000000000000..888b5596c195 --- /dev/null +++ b/arch/s390/lib/spinlock.c @@ -0,0 +1,133 @@ +/* + * arch/s390/lib/spinlock.c + * Out of line spinlock code. + * + * S390 version + * Copyright (C) 2004 IBM Deutschland Entwicklung GmbH, IBM Corporation + * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com) + */ + +#include <linux/types.h> +#include <linux/module.h> +#include <linux/spinlock.h> +#include <linux/init.h> +#include <asm/io.h> + +atomic_t spin_retry_counter; +int spin_retry = 1000; + +/** + * spin_retry= parameter + */ +static int __init spin_retry_setup(char *str) +{ + spin_retry = simple_strtoul(str, &str, 0); + return 1; +} +__setup("spin_retry=", spin_retry_setup); + +static inline void +_diag44(void) +{ +#ifdef __s390x__ + if (MACHINE_HAS_DIAG44) +#endif + asm volatile("diag 0,0,0x44"); +} + +void +_raw_spin_lock_wait(spinlock_t *lp, unsigned int pc) +{ + int count = spin_retry; + + while (1) { + if (count-- <= 0) { + _diag44(); + count = spin_retry; + } + atomic_inc(&spin_retry_counter); + if (_raw_compare_and_swap(&lp->lock, 0, pc) == 0) + return; + } +} +EXPORT_SYMBOL(_raw_spin_lock_wait); + +int +_raw_spin_trylock_retry(spinlock_t *lp, unsigned int pc) +{ + int count = spin_retry; + + while (count-- > 0) { + atomic_inc(&spin_retry_counter); + if (_raw_compare_and_swap(&lp->lock, 0, pc) == 0) + return 1; + } + return 0; +} +EXPORT_SYMBOL(_raw_spin_trylock_retry); + +void +_raw_read_lock_wait(rwlock_t *rw) +{ + unsigned int old; + int count = spin_retry; + + while (1) { + if (count-- <= 0) { + _diag44(); + count = spin_retry; + } + atomic_inc(&spin_retry_counter); + old = rw->lock & 0x7fffffffU; + if (_raw_compare_and_swap(&rw->lock, old, old + 1) == old) + return; + } +} +EXPORT_SYMBOL(_raw_read_lock_wait); + +int +_raw_read_trylock_retry(rwlock_t *rw) +{ + unsigned int old; + int count = spin_retry; + + while (count-- > 0) { + atomic_inc(&spin_retry_counter); + old = rw->lock & 0x7fffffffU; + if (_raw_compare_and_swap(&rw->lock, old, old + 1) == old) + return 1; + } + return 0; +} +EXPORT_SYMBOL(_raw_read_trylock_retry); + +void +_raw_write_lock_wait(rwlock_t *rw) +{ + int count = spin_retry; + + while (1) { + if (count-- <= 0) { + _diag44(); + count = spin_retry; + } + atomic_inc(&spin_retry_counter); + if (_raw_compare_and_swap(&rw->lock, 0, 0x80000000) == 0) + return; + } +} +EXPORT_SYMBOL(_raw_write_lock_wait); + +int +_raw_write_trylock_retry(rwlock_t *rw) +{ + int count = spin_retry; + + while (count-- > 0) { + atomic_inc(&spin_retry_counter); + if (_raw_compare_and_swap(&rw->lock, 0, 0x80000000) == 0) + return 1; + } + return 0; +} +EXPORT_SYMBOL(_raw_write_trylock_retry); |