diff options
| -rw-r--r-- | sys/arch/sparc64/include/mplock.h | 12 | ||||
| -rw-r--r-- | sys/arch/sparc64/sparc64/lock_machdep.c | 105 |
2 files changed, 46 insertions, 71 deletions
diff --git a/sys/arch/sparc64/include/mplock.h b/sys/arch/sparc64/include/mplock.h index aa133e36686..7b7d9cc7a59 100644 --- a/sys/arch/sparc64/include/mplock.h +++ b/sys/arch/sparc64/include/mplock.h @@ -1,4 +1,4 @@ -/* $OpenBSD: mplock.h,v 1.2 2007/11/27 23:29:57 kettenis Exp $ */ +/* $OpenBSD: mplock.h,v 1.3 2014/03/14 01:20:44 dlg Exp $ */ /* * Copyright (c) 2004 Niklas Hallqvist. All rights reserved. @@ -27,9 +27,15 @@ #ifndef _MACHINE_MPLOCK_H_ #define _MACHINE_MPLOCK_H_ +struct __mp_lock_cpu { + volatile u_int mplc_ticket; + volatile u_int mplc_depth; +}; + struct __mp_lock { - volatile struct cpu_info *mpl_cpu; - volatile long mpl_count; + struct __mp_lock_cpu mpl_cpus[MAXCPUS]; + volatile u_int mpl_ticket; + volatile u_int mpl_users; }; #ifndef _LOCORE diff --git a/sys/arch/sparc64/sparc64/lock_machdep.c b/sys/arch/sparc64/sparc64/lock_machdep.c index 3958e8cbb74..c653ae03faa 100644 --- a/sys/arch/sparc64/sparc64/lock_machdep.c +++ b/sys/arch/sparc64/sparc64/lock_machdep.c @@ -1,4 +1,4 @@ -/* $OpenBSD: lock_machdep.c,v 1.5 2014/01/30 00:51:13 dlg Exp $ */ +/* $OpenBSD: lock_machdep.c,v 1.6 2014/03/14 01:20:44 dlg Exp $ */ /* * Copyright (c) 2007 Artur Grabowski <art@openbsd.org> @@ -27,10 +27,11 @@ #include <ddb/db_output.h> void -__mp_lock_init(struct __mp_lock *lock) +__mp_lock_init(struct __mp_lock *mpl) { - lock->mpl_cpu = NULL; - lock->mpl_count = 0; + memset(mpl->mpl_cpus, 0, sizeof(mpl->mpl_cpus)); + mpl->mpl_users = 0; + mpl->mpl_ticket = 1; } #if defined(MP_LOCKDEBUG) @@ -76,15 +77,15 @@ __mp_lock_spin_hook(void) #define SPINLOCK_SPIN_HOOK __mp_lock_spin_hook() static __inline void -__mp_lock_spin(struct __mp_lock *mpl) +__mp_lock_spin(struct __mp_lock *mpl, u_int me) { #ifndef MP_LOCKDEBUG - while (mpl->mpl_count != 0) + while (mpl->mpl_ticket != me) SPINLOCK_SPIN_HOOK; #else int ticks = __mp_lock_spinout; - while (mpl->mpl_count != 0 && --ticks > 0) + while (mpl->mpl_ticket != me && --ticks > 0) SPINLOCK_SPIN_HOOK; if (ticks == 0) { @@ -97,55 +98,28 @@ __mp_lock_spin(struct __mp_lock *mpl) void __mp_lock(struct __mp_lock *mpl) { - /* - * Please notice that mpl_count gets incremented twice for the - * first lock. This is on purpose. The way we release the lock - * in mp_unlock is to decrement the mpl_count and then check if - * the lock should be released. Since mpl_count is what we're - * spinning on, decrementing it in mpl_unlock to 0 means that - * we can't clear mpl_cpu, because we're no longer holding the - * lock. In theory mpl_cpu doesn't need to be cleared, but it's - * safer to clear it and besides, setting mpl_count to 2 on the - * first lock makes most of this code much simpler. - */ - - while (1) { - u_int64_t s; - - s = intr_disable(); - if (atomic_cas_ulong(&mpl->mpl_count, 0, 1) == 0) { - sparc_membar(LoadLoad | LoadStore); - mpl->mpl_cpu = curcpu(); - } - - if (mpl->mpl_cpu == curcpu()) { - mpl->mpl_count++; - intr_restore(s); - break; - } - intr_restore(s); - - __mp_lock_spin(mpl); - } + struct __mp_lock_cpu *cpu = &mpl->mpl_cpus[cpu_number()]; + u_int64_t s; + + s = intr_disable(); + if (cpu->mplc_depth++ == 0) + cpu->mplc_ticket = atomic_inc_int_nv(&mpl->mpl_users); + intr_restore(s); + + __mp_lock_spin(mpl, cpu->mplc_ticket); + sparc_membar(LoadLoad | LoadStore); } void __mp_unlock(struct __mp_lock *mpl) { + struct __mp_lock_cpu *cpu = &mpl->mpl_cpus[cpu_number()]; u_int64_t s; -#ifdef MP_LOCKDEBUG - if (mpl->mpl_cpu != curcpu()) { - db_printf("__mp_unlock(%p): not held lock\n", mpl); - Debugger(); - } -#endif - s = intr_disable(); - if (--mpl->mpl_count == 1) { - mpl->mpl_cpu = NULL; + if (--cpu->mplc_depth == 0) { + mpl->mpl_ticket++; sparc_membar(StoreStore | LoadStore); - mpl->mpl_count = 0; } intr_restore(s); } @@ -153,20 +127,15 @@ __mp_unlock(struct __mp_lock *mpl) int __mp_release_all(struct __mp_lock *mpl) { - int rv = mpl->mpl_count - 1; + struct __mp_lock_cpu *cpu = &mpl->mpl_cpus[cpu_number()]; u_int64_t s; - -#ifdef MP_LOCKDEBUG - if (mpl->mpl_cpu != curcpu()) { - db_printf("__mp_release_all(%p): not held lock\n", mpl); - Debugger(); - } -#endif + int rv; s = intr_disable(); - mpl->mpl_cpu = NULL; + rv = cpu->mplc_depth; + cpu->mplc_depth = 0; + mpl->mpl_ticket++; sparc_membar(StoreStore | LoadStore); - mpl->mpl_count = 0; intr_restore(s); return (rv); @@ -175,18 +144,16 @@ __mp_release_all(struct __mp_lock *mpl) int __mp_release_all_but_one(struct __mp_lock *mpl) { - int rv = mpl->mpl_count - 2; - -#ifdef MP_LOCKDEBUG - if (mpl->mpl_cpu != curcpu()) { - db_printf("__mp_release_all_but_one(%p): not held lock\n", mpl); - Debugger(); - } -#endif + struct __mp_lock_cpu *cpu = &mpl->mpl_cpus[cpu_number()]; + u_int64_t s; + int rv; - mpl->mpl_count = 2; + s = intr_disable(); + rv = cpu->mplc_depth; + cpu->mplc_depth = 1; + intr_restore(s); - return (rv); + return (rv - 1); } void @@ -199,5 +166,7 @@ __mp_acquire_count(struct __mp_lock *mpl, int count) int __mp_lock_held(struct __mp_lock *mpl) { - return mpl->mpl_cpu == curcpu(); + struct __mp_lock_cpu *cpu = &mpl->mpl_cpus[cpu_number()]; + + return (cpu->mplc_ticket == mpl->mpl_ticket && cpu->mplc_depth > 0); } |