diff --git a/arch/Kconfig b/arch/Kconfig index 1feb169274fe613cc5f0360c797668bf84497c4b..af2cc6eabcc781c4e8f7ee2067de75844ed5874d 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -286,9 +286,6 @@ config HAVE_PERF_USER_STACK_DUMP config HAVE_ARCH_JUMP_LABEL bool -config HAVE_ARCH_MUTEX_CPU_RELAX - bool - config HAVE_RCU_TABLE_FREE bool diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index dcc6ac2d802637ab6e5fb9c004eaa69ba5e01479..7143793859fadf0cbc66c1b2119c5cbaee6368c8 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -93,6 +93,7 @@ config S390 select ARCH_INLINE_WRITE_UNLOCK_IRQ select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE select ARCH_SAVE_PAGE_KEYS if HIBERNATION + select ARCH_USE_CMPXCHG_LOCKREF select ARCH_WANT_IPC_PARSE_VERSION select BUILDTIME_EXTABLE_SORT select CLONE_BACKWARDS2 @@ -102,7 +103,6 @@ config S390 select GENERIC_TIME_VSYSCALL_OLD select HAVE_ALIGNED_STRUCT_PAGE if SLUB select HAVE_ARCH_JUMP_LABEL if !MARCH_G5 - select HAVE_ARCH_MUTEX_CPU_RELAX select HAVE_ARCH_SECCOMP_FILTER select HAVE_ARCH_TRACEHOOK select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT diff --git a/arch/s390/include/asm/mutex.h b/arch/s390/include/asm/mutex.h index 688271f5f2e452b9951599550f33ed0ddcfe0a7c..458c1f7fbc1808d48982aa0c5fe89bfe3df2098c 100644 --- a/arch/s390/include/asm/mutex.h +++ b/arch/s390/include/asm/mutex.h @@ -7,5 +7,3 @@ */ #include - -#define arch_mutex_cpu_relax() barrier() diff --git a/arch/s390/include/asm/processor.h b/arch/s390/include/asm/processor.h index 0eb37505cab11c71f083ed508f02c98a72127e95..ca7821f07260301f26c2ff9314432b193ad8bebf 100644 --- a/arch/s390/include/asm/processor.h +++ b/arch/s390/include/asm/processor.h @@ -198,6 +198,8 @@ static inline void cpu_relax(void) barrier(); } +#define arch_mutex_cpu_relax() barrier() + static inline void psw_set_key(unsigned int key) { asm volatile("spka 0(%0)" : : "d" (key)); diff --git a/arch/s390/include/asm/spinlock.h b/arch/s390/include/asm/spinlock.h index 701fe8c59e1f0e9efc302e711eef5bcfe3db479a..83e5d216105e86a2df2ab1367bcfc3fd1590542a 100644 --- a/arch/s390/include/asm/spinlock.h +++ b/arch/s390/include/asm/spinlock.h @@ -44,6 +44,11 @@ extern void arch_spin_lock_wait_flags(arch_spinlock_t *, unsigned long flags); extern int arch_spin_trylock_retry(arch_spinlock_t *); extern void arch_spin_relax(arch_spinlock_t *lock); +static inline int arch_spin_value_unlocked(arch_spinlock_t lock) +{ + return lock.owner_cpu == 0; +} + static inline void arch_spin_lock(arch_spinlock_t *lp) { int old; diff --git a/include/linux/mutex.h b/include/linux/mutex.h index ccd4260834c57da2ea30fc5b20714ef15afe076f..bab49da8a0f0b1bd2e01d516fdd0e39a07162326 100644 --- a/include/linux/mutex.h +++ b/include/linux/mutex.h @@ -15,8 +15,8 @@ #include #include #include - #include +#include /* * Simple, straightforward mutexes with strict semantics: @@ -175,8 +175,8 @@ extern void mutex_unlock(struct mutex *lock); extern int atomic_dec_and_mutex_lock(atomic_t *cnt, struct mutex *lock); -#ifndef CONFIG_HAVE_ARCH_MUTEX_CPU_RELAX -#define arch_mutex_cpu_relax() cpu_relax() +#ifndef arch_mutex_cpu_relax +# define arch_mutex_cpu_relax() cpu_relax() #endif #endif diff --git a/lib/lockref.c b/lib/lockref.c index e294ae445c9ab4b7e97dd1a46efc7dc7d6a1848d..6f9d434c1521eab9ca0b2821d10936af55f2b703 100644 --- a/lib/lockref.c +++ b/lib/lockref.c @@ -11,6 +11,14 @@ # define cmpxchg64_relaxed cmpxchg64 #endif +/* + * Allow architectures to override the default cpu_relax() within CMPXCHG_LOOP. + * This is useful for architectures with an expensive cpu_relax(). + */ +#ifndef arch_mutex_cpu_relax +# define arch_mutex_cpu_relax() cpu_relax() +#endif + /* * Note that the "cmpxchg()" reloads the "old" value for the * failure case. @@ -28,7 +36,7 @@ if (likely(old.lock_count == prev.lock_count)) { \ SUCCESS; \ } \ - cpu_relax(); \ + arch_mutex_cpu_relax(); \ } \ } while (0)