locking/atomic: delete !ARCH_ATOMIC remnants

Now that all architectures implement ARCH_ATOMIC, we can make it
mandatory, removing the Kconfig symbol and logic for !ARCH_ATOMIC.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210525140232.53872-33-mark.rutland@arm.com

arch/Kconfig

@@ -11,9 +11,6 @@ source "arch/$(SRCARCH)/Kconfig"
 
 menu "General architecture-dependent options"
 
-config ARCH_ATOMIC
-	bool
-
 config CRASH_CORE
 	bool
 

arch/alpha/Kconfig

@@ -2,7 +2,6 @@
 config ALPHA
 	bool
 	default y
-	select ARCH_ATOMIC
 	select ARCH_32BIT_USTAT_F_TINODE
 	select ARCH_MIGHT_HAVE_PC_PARPORT
 	select ARCH_MIGHT_HAVE_PC_SERIO

arch/arc/Kconfig

@@ -6,7 +6,6 @@
 config ARC
 	def_bool y
 	select ARC_TIMERS
-	select ARCH_ATOMIC
 	select ARCH_HAS_CACHE_LINE_SIZE
 	select ARCH_HAS_DEBUG_VM_PGTABLE
 	select ARCH_HAS_DMA_PREP_COHERENT

arch/arm/Kconfig

@@ -3,7 +3,6 @@ config ARM
 	bool
 	default y
 	select ARCH_32BIT_OFF_T
-	select ARCH_ATOMIC
 	select ARCH_HAS_BINFMT_FLAT
 	select ARCH_HAS_DEBUG_VIRTUAL if MMU
 	select ARCH_HAS_DMA_WRITE_COMBINE if !ARM_DMA_MEM_BUFFERABLE

arch/arm64/Kconfig

@@ -9,7 +9,6 @@ config ARM64
 	select ACPI_MCFG if (ACPI && PCI)
 	select ACPI_SPCR_TABLE if ACPI
 	select ACPI_PPTT if ACPI
-	select ARCH_ATOMIC
 	select ARCH_HAS_DEBUG_WX
 	select ARCH_BINFMT_ELF_STATE
 	select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION

arch/csky/Kconfig

@@ -2,7 +2,6 @@
 config CSKY
 	def_bool y
 	select ARCH_32BIT_OFF_T
-	select ARCH_ATOMIC
 	select ARCH_HAS_DMA_PREP_COHERENT
 	select ARCH_HAS_GCOV_PROFILE_ALL
 	select ARCH_HAS_SYNC_DMA_FOR_CPU

arch/h8300/Kconfig

@@ -2,7 +2,6 @@
 config H8300
         def_bool y
 	select ARCH_32BIT_OFF_T
-	select ARCH_ATOMIC
 	select ARCH_HAS_BINFMT_FLAT
 	select BINFMT_FLAT_ARGVP_ENVP_ON_STACK
 	select BINFMT_FLAT_OLD_ALWAYS_RAM

arch/hexagon/Kconfig

@@ -5,7 +5,6 @@ comment "Linux Kernel Configuration for Hexagon"
 config HEXAGON
 	def_bool y
 	select ARCH_32BIT_OFF_T
-	select ARCH_ATOMIC
 	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
 	select ARCH_NO_PREEMPT
 	# Other pending projects/to-do items.

arch/ia64/Kconfig

@@ -8,7 +8,6 @@ menu "Processor type and features"
 
 config IA64
 	bool
-	select ARCH_ATOMIC
 	select ARCH_HAS_DMA_MARK_CLEAN
 	select ARCH_MIGHT_HAVE_PC_PARPORT
 	select ARCH_MIGHT_HAVE_PC_SERIO

arch/m68k/Kconfig

@@ -3,7 +3,6 @@ config M68K
 	bool
 	default y
 	select ARCH_32BIT_OFF_T
-	select ARCH_ATOMIC
 	select ARCH_HAS_BINFMT_FLAT
 	select ARCH_HAS_DMA_PREP_COHERENT if HAS_DMA && MMU && !COLDFIRE
 	select ARCH_HAS_SYNC_DMA_FOR_DEVICE if HAS_DMA

arch/microblaze/Kconfig

@@ -2,7 +2,6 @@
 config MICROBLAZE
 	def_bool y
 	select ARCH_32BIT_OFF_T
-	select ARCH_ATOMIC
 	select ARCH_NO_SWAP
 	select ARCH_HAS_DMA_PREP_COHERENT
 	select ARCH_HAS_GCOV_PROFILE_ALL

arch/mips/Kconfig

@@ -3,7 +3,6 @@ config MIPS
 	bool
 	default y
 	select ARCH_32BIT_OFF_T if !64BIT
-	select ARCH_ATOMIC
 	select ARCH_BINFMT_ELF_STATE if MIPS_FP_SUPPORT
 	select ARCH_HAS_DEBUG_VIRTUAL if !64BIT
 	select ARCH_HAS_FORTIFY_SOURCE

arch/nds32/Kconfig

@@ -7,7 +7,6 @@
 config NDS32
 	def_bool y
 	select ARCH_32BIT_OFF_T
-	select ARCH_ATOMIC
 	select ARCH_HAS_DMA_PREP_COHERENT
 	select ARCH_HAS_SYNC_DMA_FOR_CPU
 	select ARCH_HAS_SYNC_DMA_FOR_DEVICE

arch/nios2/Kconfig

@@ -2,7 +2,6 @@
 config NIOS2
 	def_bool y
 	select ARCH_32BIT_OFF_T
-	select ARCH_ATOMIC
 	select ARCH_HAS_DMA_PREP_COHERENT
 	select ARCH_HAS_SYNC_DMA_FOR_CPU
 	select ARCH_HAS_SYNC_DMA_FOR_DEVICE

arch/openrisc/Kconfig

@@ -7,7 +7,6 @@
 config OPENRISC
 	def_bool y
 	select ARCH_32BIT_OFF_T
-	select ARCH_ATOMIC
 	select ARCH_HAS_DMA_SET_UNCACHED
 	select ARCH_HAS_DMA_CLEAR_UNCACHED
 	select ARCH_HAS_SYNC_DMA_FOR_DEVICE

arch/parisc/Kconfig

@@ -2,7 +2,6 @@
 config PARISC
 	def_bool y
 	select ARCH_32BIT_OFF_T if !64BIT
-	select ARCH_ATOMIC
 	select ARCH_MIGHT_HAVE_PC_PARPORT
 	select HAVE_IDE
 	select HAVE_FUNCTION_TRACER

arch/powerpc/Kconfig

@@ -118,7 +118,6 @@ config PPC
 	# Please keep this list sorted alphabetically.
 	#
 	select ARCH_32BIT_OFF_T if PPC32
-	select ARCH_ATOMIC
 	select ARCH_ENABLE_MEMORY_HOTPLUG
 	select ARCH_ENABLE_MEMORY_HOTREMOVE
 	select ARCH_HAS_COPY_MC			if PPC64

arch/riscv/Kconfig

@@ -12,7 +12,6 @@ config 32BIT
 
 config RISCV
 	def_bool y
-	select ARCH_ATOMIC
 	select ARCH_CLOCKSOURCE_INIT
 	select ARCH_SUPPORTS_ATOMIC_RMW
 	select ARCH_SUPPORTS_DEBUG_PAGEALLOC if MMU

arch/s390/Kconfig

@@ -58,7 +58,6 @@ config S390
 	# Note: keep this list sorted alphabetically
 	#
 	imply IMA_SECURE_AND_OR_TRUSTED_BOOT
-	select ARCH_ATOMIC
 	select ARCH_32BIT_USTAT_F_TINODE
 	select ARCH_BINFMT_ELF_STATE
 	select ARCH_ENABLE_MEMORY_HOTPLUG if SPARSEMEM

arch/sh/Kconfig

@@ -2,7 +2,6 @@
 config SUPERH
 	def_bool y
 	select ARCH_32BIT_OFF_T
-	select ARCH_ATOMIC
 	select ARCH_ENABLE_MEMORY_HOTPLUG if SPARSEMEM && MMU
 	select ARCH_ENABLE_MEMORY_HOTREMOVE if SPARSEMEM && MMU
 	select ARCH_HAVE_CUSTOM_GPIO_H

arch/sparc/Kconfig

@@ -13,7 +13,6 @@ config 64BIT
 config SPARC
 	bool
 	default y
-	select ARCH_ATOMIC
 	select ARCH_MIGHT_HAVE_PC_PARPORT if SPARC64 && PCI
 	select ARCH_MIGHT_HAVE_PC_SERIO
 	select DMA_OPS

arch/um/Kconfig

@@ -5,7 +5,6 @@ menu "UML-specific options"
 config UML
 	bool
 	default y
-	select ARCH_ATOMIC
 	select ARCH_EPHEMERAL_INODES
 	select ARCH_HAS_KCOV
 	select ARCH_NO_PREEMPT

arch/x86/Kconfig

@@ -58,7 +58,6 @@ config X86
 	#
 	select ACPI_LEGACY_TABLES_LOOKUP	if ACPI
 	select ACPI_SYSTEM_POWER_STATES_SUPPORT	if ACPI
-	select ARCH_ATOMIC
 	select ARCH_32BIT_OFF_T			if X86_32
 	select ARCH_CLOCKSOURCE_INIT
 	select ARCH_ENABLE_HUGEPAGE_MIGRATION if X86_64 && HUGETLB_PAGE && MIGRATION

arch/xtensa/Kconfig

@@ -2,7 +2,6 @@
 config XTENSA
 	def_bool y
 	select ARCH_32BIT_OFF_T
-	select ARCH_ATOMIC
 	select ARCH_HAS_BINFMT_FLAT if !MMU
 	select ARCH_HAS_DMA_PREP_COHERENT if MMU
 	select ARCH_HAS_SYNC_DMA_FOR_CPU if MMU

include/asm-generic/atomic.h

@@ -12,14 +12,6 @@
 #include <asm/cmpxchg.h>
 #include <asm/barrier.h>
 
-#ifdef CONFIG_ARCH_ATOMIC
-#define __ga_cmpxchg	arch_cmpxchg
-#define __ga_xchg	arch_xchg
-#else
-#define __ga_cmpxchg	cmpxchg
-#define __ga_xchg	xchg
-#endif
-
 #ifdef CONFIG_SMP
 
 /* we can build all atomic primitives from cmpxchg */
@@ -30,7 +22,7 @@ static inline void generic_atomic_##op(int i, atomic_t *v)		\
 	int c, old;							\
 									\
 	c = v->counter;							\
-	while ((old = __ga_cmpxchg(&v->counter, c, c c_op i)) != c)	\
+	while ((old = arch_cmpxchg(&v->counter, c, c c_op i)) != c)	\
 		c = old;						\
 }
 
@@ -40,7 +32,7 @@ static inline int generic_atomic_##op##_return(int i, atomic_t *v)	\
 	int c, old;							\
 									\
 	c = v->counter;							\
-	while ((old = __ga_cmpxchg(&v->counter, c, c c_op i)) != c)	\
+	while ((old = arch_cmpxchg(&v->counter, c, c c_op i)) != c)	\
 		c = old;						\
 									\
 	return c c_op i;						\
@@ -52,7 +44,7 @@ static inline int generic_atomic_fetch_##op(int i, atomic_t *v)		\
 	int c, old;							\
 									\
 	c = v->counter;							\
-	while ((old = __ga_cmpxchg(&v->counter, c, c c_op i)) != c)	\
+	while ((old = arch_cmpxchg(&v->counter, c, c c_op i)) != c)	\
 		c = old;						\
 									\
 	return c;							\
@@ -120,11 +112,6 @@ ATOMIC_OP(xor, ^)
 #undef ATOMIC_OP_RETURN
 #undef ATOMIC_OP
 
-#undef __ga_cmpxchg
-#undef __ga_xchg
-
-#ifdef CONFIG_ARCH_ATOMIC
-
 #define arch_atomic_add_return			generic_atomic_add_return
 #define arch_atomic_sub_return			generic_atomic_sub_return
 
@@ -146,29 +133,4 @@ ATOMIC_OP(xor, ^)
 #define arch_atomic_xchg(ptr, v)		(arch_xchg(&(ptr)->counter, (v)))
 #define arch_atomic_cmpxchg(v, old, new)	(arch_cmpxchg(&((v)->counter), (old), (new)))
 
-#else /* CONFIG_ARCH_ATOMIC */
-
-#define atomic_add_return		generic_atomic_add_return
-#define atomic_sub_return		generic_atomic_sub_return
-
-#define atomic_fetch_add		generic_atomic_fetch_add
-#define atomic_fetch_sub		generic_atomic_fetch_sub
-#define atomic_fetch_and		generic_atomic_fetch_and
-#define atomic_fetch_or			generic_atomic_fetch_or
-#define atomic_fetch_xor		generic_atomic_fetch_xor
-
-#define atomic_add			generic_atomic_add
-#define atomic_sub			generic_atomic_sub
-#define atomic_and			generic_atomic_and
-#define atomic_or			generic_atomic_or
-#define atomic_xor			generic_atomic_xor
-
-#define atomic_read(v)			READ_ONCE((v)->counter)
-#define atomic_set(v, i)		WRITE_ONCE(((v)->counter), (i))
-
-#define atomic_xchg(ptr, v)		(xchg(&(ptr)->counter, (v)))
-#define atomic_cmpxchg(v, old, new)	(cmpxchg(&((v)->counter), (old), (new)))
-
-#endif /* CONFIG_ARCH_ATOMIC */
-
 #endif /* __ASM_GENERIC_ATOMIC_H */

include/asm-generic/atomic64.h

@@ -49,8 +49,6 @@ extern s64 generic_atomic64_cmpxchg(atomic64_t *v, s64 o, s64 n);
 extern s64 generic_atomic64_xchg(atomic64_t *v, s64 new);
 extern s64 generic_atomic64_fetch_add_unless(atomic64_t *v, s64 a, s64 u);
 
-#ifdef CONFIG_ARCH_ATOMIC
-
 #define arch_atomic64_read		generic_atomic64_read
 #define arch_atomic64_set		generic_atomic64_set
 #define arch_atomic64_set_release	generic_atomic64_set
@@ -74,31 +72,4 @@ extern s64 generic_atomic64_fetch_add_unless(atomic64_t *v, s64 a, s64 u);
 #define arch_atomic64_xchg		generic_atomic64_xchg
 #define arch_atomic64_fetch_add_unless	generic_atomic64_fetch_add_unless
 
-#else /* CONFIG_ARCH_ATOMIC */
-
-#define atomic64_read			generic_atomic64_read
-#define atomic64_set			generic_atomic64_set
-#define atomic64_set_release		generic_atomic64_set
-
-#define atomic64_add			generic_atomic64_add
-#define atomic64_add_return		generic_atomic64_add_return
-#define atomic64_fetch_add		generic_atomic64_fetch_add
-#define atomic64_sub			generic_atomic64_sub
-#define atomic64_sub_return		generic_atomic64_sub_return
-#define atomic64_fetch_sub		generic_atomic64_fetch_sub
-
-#define atomic64_and			generic_atomic64_and
-#define atomic64_fetch_and		generic_atomic64_fetch_and
-#define atomic64_or			generic_atomic64_or
-#define atomic64_fetch_or		generic_atomic64_fetch_or
-#define atomic64_xor			generic_atomic64_xor
-#define atomic64_fetch_xor		generic_atomic64_fetch_xor
-
-#define atomic64_dec_if_positive	generic_atomic64_dec_if_positive
-#define atomic64_cmpxchg		generic_atomic64_cmpxchg
-#define atomic64_xchg			generic_atomic64_xchg
-#define atomic64_fetch_add_unless	generic_atomic64_fetch_add_unless
-
-#endif /* CONFIG_ARCH_ATOMIC */
-
 #endif  /*  _ASM_GENERIC_ATOMIC64_H  */

include/asm-generic/cmpxchg.h

@@ -97,8 +97,6 @@ unsigned long __generic_xchg(unsigned long x, volatile void *ptr, int size)
 	__generic_cmpxchg64_local((ptr), (o), (n))
 
 
-#ifdef CONFIG_ARCH_ATOMIC
-
 #ifndef arch_xchg
 #define arch_xchg		generic_xchg
 #endif
@@ -114,23 +112,4 @@ unsigned long __generic_xchg(unsigned long x, volatile void *ptr, int size)
 #define arch_cmpxchg		arch_cmpxchg_local
 #define arch_cmpxchg64		arch_cmpxchg64_local
 
-#else /* CONFIG_ARCH_ATOMIC */
-
-#ifndef xchg
-#define xchg			generic_xchg
-#endif
-
-#ifndef cmpxchg_local
-#define cmpxchg_local		generic_cmpxchg_local
-#endif
-
-#ifndef cmpxchg64_local
-#define cmpxchg64_local		generic_cmpxchg64_local
-#endif
-
-#define cmpxchg			cmpxchg_local
-#define cmpxchg64		cmpxchg64_local
-
-#endif /* CONFIG_ARCH_ATOMIC */
-
 #endif /* __ASM_GENERIC_CMPXCHG_H */

include/linux/atomic.h

@@ -77,12 +77,8 @@
 	__ret;								\
 })
 
-#ifdef CONFIG_ARCH_ATOMIC
 #include <linux/atomic-arch-fallback.h>
 #include <asm-generic/atomic-instrumented.h>
-#else
-#include <linux/atomic-fallback.h>
-#endif
 
 #include <asm-generic/atomic-long.h>
 

scripts/atomic/check-atomics.sh

@@ -17,7 +17,6 @@ cat <<EOF |
 asm-generic/atomic-instrumented.h
 asm-generic/atomic-long.h
 linux/atomic-arch-fallback.h
-linux/atomic-fallback.h
 EOF
 while read header; do
 	OLDSUM="$(tail -n 1 ${LINUXDIR}/include/${header})"

scripts/atomic/gen-atomics.sh

@@ -11,7 +11,6 @@ cat <<EOF |
 gen-atomic-instrumented.sh      asm-generic/atomic-instrumented.h
 gen-atomic-long.sh              asm-generic/atomic-long.h
 gen-atomic-fallback.sh          linux/atomic-arch-fallback.h		arch_
-gen-atomic-fallback.sh          linux/atomic-fallback.h
 EOF
 while read script header args; do
 	/bin/sh ${ATOMICDIR}/${script} ${ATOMICTBL} ${args} > ${LINUXDIR}/include/${header}