atomic64_test: simplify the #ifdef for atomic64_dec_if_positive() test

Introduce CONFIG_ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE and use this instead
of the multitude of #if defined() checks in atomic64_test.c

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/arm/Kconfig

@@ -11,6 +11,7 @@ config ARM
 	select RTC_LIB
 	select SYS_SUPPORTS_APM_EMULATION
 	select GENERIC_ATOMIC64 if (CPU_V6 || !CPU_32v6K || !AEABI)
+	select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
 	select HAVE_OPROFILE if (HAVE_PERF_EVENTS)
 	select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL
 	select HAVE_ARCH_KGDB

arch/mips/Kconfig

@@ -20,6 +20,7 @@ config MIPS
 	select ARCH_BINFMT_ELF_RANDOMIZE_PIE
 	select RTC_LIB if !MACH_LOONGSON
 	select GENERIC_ATOMIC64 if !64BIT
+	select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
 	select HAVE_DMA_ATTRS
 	select HAVE_DMA_API_DEBUG
 	select HAVE_GENERIC_HARDIRQS

arch/powerpc/Kconfig

@@ -115,6 +115,7 @@ config PPC
 	select HAVE_OPROFILE
 	select HAVE_SYSCALL_WRAPPERS if PPC64
 	select GENERIC_ATOMIC64 if PPC32
+	select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
 	select HAVE_IRQ_WORK
 	select HAVE_PERF_EVENTS
 	select HAVE_REGS_AND_STACK_ACCESS_API

arch/s390/Kconfig

@@ -85,6 +85,7 @@ config S390
 	select HAVE_ARCH_MUTEX_CPU_RELAX
 	select HAVE_ARCH_JUMP_LABEL if !MARCH_G5
 	select ARCH_SAVE_PAGE_KEYS if HIBERNATION
+	select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
 	select HAVE_MEMBLOCK
 	select HAVE_MEMBLOCK_NODE_MAP
 	select HAVE_CMPXCHG_LOCAL

arch/x86/Kconfig

@@ -70,6 +70,7 @@ config X86
 	select HAVE_ARCH_JUMP_LABEL
 	select HAVE_TEXT_POKE_SMP
 	select HAVE_GENERIC_HARDIRQS
+	select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
 	select SPARSE_IRQ
 	select GENERIC_FIND_FIRST_BIT
 	select GENERIC_IRQ_PROBE

lib/Kconfig

@@ -340,6 +340,9 @@ config NLATTR
 config GENERIC_ATOMIC64
        bool
 
+config ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
+	def_bool y if GENERIC_ATOMIC64
+
 config LRU_CACHE
 	tristate
 

lib/atomic64_test.c

@@ -114,8 +114,7 @@ static __init int test_atomic64(void)
 	r += one;
 	BUG_ON(v.counter != r);
 
-#if defined(CONFIG_X86) || defined(CONFIG_MIPS) || defined(CONFIG_PPC) || \
-    defined(CONFIG_S390) || defined(_ASM_GENERIC_ATOMIC64_H) || defined(CONFIG_ARM)
+#ifdef CONFIG_ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
 	INIT(onestwos);
 	BUG_ON(atomic64_dec_if_positive(&v) != (onestwos - 1));
 	r -= one;
@@ -129,7 +128,7 @@ static __init int test_atomic64(void)
 	BUG_ON(atomic64_dec_if_positive(&v) != (-one - one));
 	BUG_ON(v.counter != r);
 #else
-#warning Please implement atomic64_dec_if_positive for your architecture, and add it to the IF above
+#warning Please implement atomic64_dec_if_positive for your architecture and select the above Kconfig symbol
 #endif
 
 	INIT(onestwos);