mutex: replace CONFIG_HAVE_ARCH_MUTEX_CPU_RELAX with simple ifdef

Linus suggested to replace

 #ifndef CONFIG_HAVE_ARCH_MUTEX_CPU_RELAX
 #define arch_mutex_cpu_relax() cpu_relax()
 #endif

with just a simple

  #ifndef arch_mutex_cpu_relax
  # define arch_mutex_cpu_relax() cpu_relax()
  #endif

to get rid of CONFIG_HAVE_CPU_RELAX_SIMPLE. So architectures can
simply define arch_mutex_cpu_relax if they want an architecture
specific function instead of having to add a select statement in
their Kconfig in addition.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>

4 files changed, 2 insertions, 6 deletions

diff --git a/arch/Kconfig b/arch/Kconfig
index 1feb169274fe..af2cc6eabcc7 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 dcc6ac2d8026..d3fa84070b82 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -102,7 +102,6 @@ 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 688271f5f2e4..458c1f7fbc18 100644
--- a/arch/s390/include/asm/mutex.h
+++ b/arch/s390/include/asm/mutex.h
@@ -7,5 +7,3 @@
  */
 
 #include <asm-generic/mutex-dec.h>
-
-#define arch_mutex_cpu_relax()  barrier()
diff --git a/arch/s390/include/asm/processor.h b/arch/s390/include/asm/processor.h
index 0eb37505cab1..ca7821f07260 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));