diff options
| -rw-r--r-- | arch/s390/include/asm/sigp.h | 40 | ||||
| -rw-r--r-- | arch/s390/include/asm/smp.h | 24 | ||||
| -rw-r--r-- | arch/s390/lib/spinlock.c | 53 |
3 files changed, 80 insertions, 37 deletions
diff --git a/arch/s390/include/asm/sigp.h b/arch/s390/include/asm/sigp.h index 8aa46ce4229..e3bffd4e2d6 100644 --- a/arch/s390/include/asm/sigp.h +++ b/arch/s390/include/asm/sigp.h @@ -25,29 +25,28 @@ static inline int cpu_logical_map(int cpu) } enum { - sigp_unassigned=0x0, - sigp_sense, - sigp_external_call, - sigp_emergency_signal, - sigp_start, - sigp_stop, - sigp_restart, - sigp_unassigned1, - sigp_unassigned2, - sigp_stop_and_store_status, - sigp_unassigned3, - sigp_initial_cpu_reset, - sigp_cpu_reset, - sigp_set_prefix, - sigp_store_status_at_address, - sigp_store_extended_status_at_address + sigp_sense = 1, + sigp_external_call = 2, + sigp_emergency_signal = 3, + sigp_start = 4, + sigp_stop = 5, + sigp_restart = 6, + sigp_stop_and_store_status = 9, + sigp_initial_cpu_reset = 11, + sigp_cpu_reset = 12, + sigp_set_prefix = 13, + sigp_store_status_at_address = 14, + sigp_store_extended_status_at_address = 15, + sigp_set_architecture = 18, + sigp_conditional_emergency_signal = 19, + sigp_sense_running = 21, }; enum { - sigp_order_code_accepted=0, - sigp_status_stored, - sigp_busy, - sigp_not_operational + sigp_order_code_accepted = 0, + sigp_status_stored = 1, + sigp_busy = 2, + sigp_not_operational = 3, }; /* @@ -57,7 +56,6 @@ enum { ec_schedule = 0, ec_call_function, ec_call_function_single, - ec_bit_last }; /* diff --git a/arch/s390/include/asm/smp.h b/arch/s390/include/asm/smp.h index c2d0e638f89..edc03cb9cd7 100644 --- a/arch/s390/include/asm/smp.h +++ b/arch/s390/include/asm/smp.h @@ -36,6 +36,28 @@ extern void smp_switch_to_cpu(void (*)(void *), void *, unsigned long sp, int from, int to); extern void smp_restart_cpu(void); +/* + * returns 1 if (virtual) cpu is scheduled + * returns 0 otherwise + */ +static inline int smp_vcpu_scheduled(int cpu) +{ + u32 status; + + switch (sigp_ps(&status, 0, cpu, sigp_sense_running)) { + case sigp_status_stored: + /* Check for running status */ + if (status & 0x400) + return 0; + break; + case sigp_not_operational: + return 0; + default: + break; + } + return 1; +} + #else /* CONFIG_SMP */ static inline void smp_switch_to_ipl_cpu(void (*func)(void *), void *data) @@ -43,6 +65,8 @@ static inline void smp_switch_to_ipl_cpu(void (*func)(void *), void *data) func(data); } +#define smp_vcpu_scheduled (1) + #endif /* CONFIG_SMP */ #ifdef CONFIG_HOTPLUG_CPU diff --git a/arch/s390/lib/spinlock.c b/arch/s390/lib/spinlock.c index cff327f109a..91754ffb920 100644 --- a/arch/s390/lib/spinlock.c +++ b/arch/s390/lib/spinlock.c @@ -43,16 +43,24 @@ void arch_spin_lock_wait(arch_spinlock_t *lp) { int count = spin_retry; unsigned int cpu = ~smp_processor_id(); + unsigned int owner; while (1) { - if (count-- <= 0) { - unsigned int owner = lp->owner_cpu; - if (owner != 0) - _raw_yield_cpu(~owner); - count = spin_retry; + owner = lp->owner_cpu; + 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) + return; + } + if (MACHINE_IS_LPAR) + continue; } - if (arch_spin_is_locked(lp)) - continue; + owner = lp->owner_cpu; + if (owner) + _raw_yield_cpu(~owner); if (_raw_compare_and_swap(&lp->owner_cpu, 0, cpu) == 0) return; } @@ -63,17 +71,27 @@ void arch_spin_lock_wait_flags(arch_spinlock_t *lp, unsigned long flags) { int count = spin_retry; unsigned int cpu = ~smp_processor_id(); + unsigned int owner; local_irq_restore(flags); while (1) { - if (count-- <= 0) { - unsigned int owner = lp->owner_cpu; - if (owner != 0) - _raw_yield_cpu(~owner); - count = spin_retry; + owner = lp->owner_cpu; + 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) + return; + local_irq_restore(flags); + } + if (MACHINE_IS_LPAR) + continue; } - if (arch_spin_is_locked(lp)) - continue; + owner = lp->owner_cpu; + if (owner) + _raw_yield_cpu(~owner); local_irq_disable(); if (_raw_compare_and_swap(&lp->owner_cpu, 0, cpu) == 0) return; @@ -100,8 +118,11 @@ EXPORT_SYMBOL(arch_spin_trylock_retry); void arch_spin_relax(arch_spinlock_t *lock) { unsigned int cpu = lock->owner_cpu; - if (cpu != 0) - _raw_yield_cpu(~cpu); + if (cpu != 0) { + if (MACHINE_IS_VM || MACHINE_IS_KVM || + !smp_vcpu_scheduled(~cpu)) + _raw_yield_cpu(~cpu); + } } EXPORT_SYMBOL(arch_spin_relax); |