diff options
Diffstat (limited to 'arch/s390/lib/spinlock.c')
| -rw-r--r-- | arch/s390/lib/spinlock.c | 52 |
1 files changed, 45 insertions, 7 deletions
diff --git a/arch/s390/lib/spinlock.c b/arch/s390/lib/spinlock.c index 034a35a3e9c..d6c9991f779 100644 --- a/arch/s390/lib/spinlock.c +++ b/arch/s390/lib/spinlock.c @@ -12,7 +12,15 @@ #include <linux/smp.h> #include <asm/io.h> -int spin_retry = 1000; +int spin_retry = -1; + +static int __init spin_retry_init(void) +{ + if (spin_retry < 0) + spin_retry = MACHINE_HAS_CAD ? 10 : 1000; + return 0; +} +early_initcall(spin_retry_init); /** * spin_retry= parameter @@ -24,6 +32,11 @@ static int __init spin_retry_setup(char *str) } __setup("spin_retry=", spin_retry_setup); +static inline void _raw_compare_and_delay(unsigned int *lock, unsigned int old) +{ + asm(".insn rsy,0xeb0000000022,%0,0,%1" : : "d" (old), "Q" (*lock)); +} + void arch_spin_lock_wait(arch_spinlock_t *lp) { unsigned int cpu = SPINLOCK_LOCKVAL; @@ -46,6 +59,8 @@ void arch_spin_lock_wait(arch_spinlock_t *lp) /* Loop for a while on the lock value. */ count = spin_retry; do { + if (MACHINE_HAS_CAD) + _raw_compare_and_delay(&lp->lock, owner); owner = ACCESS_ONCE(lp->lock); } while (owner && count-- > 0); if (!owner) @@ -84,6 +99,8 @@ void arch_spin_lock_wait_flags(arch_spinlock_t *lp, unsigned long flags) /* Loop for a while on the lock value. */ count = spin_retry; do { + if (MACHINE_HAS_CAD) + _raw_compare_and_delay(&lp->lock, owner); owner = ACCESS_ONCE(lp->lock); } while (owner && count-- > 0); if (!owner) @@ -100,11 +117,19 @@ EXPORT_SYMBOL(arch_spin_lock_wait_flags); int arch_spin_trylock_retry(arch_spinlock_t *lp) { + unsigned int cpu = SPINLOCK_LOCKVAL; + unsigned int owner; int count; - for (count = spin_retry; count > 0; count--) - if (arch_spin_trylock_once(lp)) - return 1; + for (count = spin_retry; count > 0; count--) { + owner = ACCESS_ONCE(lp->lock); + /* Try to get the lock if it is free. */ + if (!owner) { + if (_raw_compare_and_swap(&lp->lock, 0, cpu)) + return 1; + } else if (MACHINE_HAS_CAD) + _raw_compare_and_delay(&lp->lock, owner); + } return 0; } EXPORT_SYMBOL(arch_spin_trylock_retry); @@ -126,8 +151,11 @@ void _raw_read_lock_wait(arch_rwlock_t *rw) } old = ACCESS_ONCE(rw->lock); owner = ACCESS_ONCE(rw->owner); - if ((int) old < 0) + if ((int) old < 0) { + if (MACHINE_HAS_CAD) + _raw_compare_and_delay(&rw->lock, old); continue; + } if (_raw_compare_and_swap(&rw->lock, old, old + 1)) return; } @@ -141,8 +169,11 @@ int _raw_read_trylock_retry(arch_rwlock_t *rw) while (count-- > 0) { old = ACCESS_ONCE(rw->lock); - if ((int) old < 0) + if ((int) old < 0) { + if (MACHINE_HAS_CAD) + _raw_compare_and_delay(&rw->lock, old); continue; + } if (_raw_compare_and_swap(&rw->lock, old, old + 1)) return 1; } @@ -173,6 +204,8 @@ void _raw_write_lock_wait(arch_rwlock_t *rw, unsigned int prev) } if ((old & 0x7fffffff) == 0 && (int) prev >= 0) break; + if (MACHINE_HAS_CAD) + _raw_compare_and_delay(&rw->lock, old); } } EXPORT_SYMBOL(_raw_write_lock_wait); @@ -201,6 +234,8 @@ void _raw_write_lock_wait(arch_rwlock_t *rw) smp_rmb(); if ((old & 0x7fffffff) == 0 && (int) prev >= 0) break; + if (MACHINE_HAS_CAD) + _raw_compare_and_delay(&rw->lock, old); } } EXPORT_SYMBOL(_raw_write_lock_wait); @@ -214,8 +249,11 @@ int _raw_write_trylock_retry(arch_rwlock_t *rw) while (count-- > 0) { old = ACCESS_ONCE(rw->lock); - if (old) + if (old) { + if (MACHINE_HAS_CAD) + _raw_compare_and_delay(&rw->lock, old); continue; + } if (_raw_compare_and_swap(&rw->lock, 0, 0x80000000)) return 1; } |