This came to light when implementing native 64-bit atomics for ARCv2.
The atomic64 self-test code uses CONFIG_ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
to check whether atomic64_dec_if_positive() is available. It seems it
was needed when not every arch defined it. However as of current code
the Kconfig option seems needless
- for CONFIG_GENERIC_ATOMIC64 it is auto-enabled in lib/Kconfig and a
generic definition of API is present lib/atomic64.c
- arches with native 64-bit atomics select it in arch/*/Kconfig and
define the API in their headers
So I see no point in keeping the Kconfig option
Compile tested for:
- blackfin (CONFIG_GENERIC_ATOMIC64)
- x86 (!CONFIG_GENERIC_ATOMIC64)
- ia64
Link: http://lkml.kernel.org/r/1473703083-8625-3-git-send-email-vgupta@synopsys.com
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Zhaoxiu Zeng <zhaoxiu.zeng@gmail.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Ming Lin <ming.l@ssi.samsung.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
select GENERIC_IRQ_SHOW
select ARCH_WANT_IPC_PARSE_VERSION
select ARCH_HAVE_NMI_SAFE_CMPXCHG
- select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
select AUDIT_ARCH
select GENERIC_CLOCKEVENTS
select GENERIC_SMP_IDLE_THREAD
bool
default y
select ARCH_CLOCKSOURCE_DATA
- select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
select ARCH_HAS_DEVMEM_IS_ALLOWED
select ARCH_HAS_ELF_RANDOMIZE
select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
select ARCH_CLOCKSOURCE_DATA
select ARCH_HAS_DEVMEM_IS_ALLOWED
select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
- select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
select ARCH_HAS_ELF_RANDOMIZE
select ARCH_HAS_GCOV_PROFILE_ALL
select ARCH_HAS_GIGANTIC_PAGE
select HAVE_ARCH_TRANSPARENT_HUGEPAGE if CPU_SUPPORTS_HUGEPAGES && 64BIT
select RTC_LIB if !MACH_LOONGSON64
select GENERIC_ATOMIC64 if !64BIT
- select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
select HAVE_DMA_CONTIGUOUS
select HAVE_DMA_API_DEBUG
select GENERIC_IRQ_PROBE
select BUILDTIME_EXTABLE_SORT
select HAVE_PERF_EVENTS
select GENERIC_ATOMIC64 if !64BIT
- select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
select BROKEN_RODATA
select GENERIC_IRQ_PROBE
select GENERIC_PCI_IOMAP
select HAVE_DEBUG_KMEMLEAK
select ARCH_HAS_SG_CHAIN
select GENERIC_ATOMIC64 if PPC32
- select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
select HAVE_PERF_EVENTS
select HAVE_PERF_REGS
select HAVE_PERF_USER_STACK_DUMP
config S390
def_bool y
- select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
select ARCH_HAS_DEVMEM_IS_ALLOWED
select ARCH_HAS_ELF_RANDOMIZE
select ARCH_HAS_GCOV_PROFILE_ALL
select HAVE_ARCH_TRACEHOOK
select HAVE_EXIT_THREAD
select SYSCTL_EXCEPTION_TRACE
- select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
select RTC_CLASS
select RTC_DRV_M48T59
select RTC_SYSTOHC
config TILE
def_bool y
- select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
select ARCH_HAS_DEVMEM_IS_ALLOWED
select ARCH_HAVE_NMI_SAFE_CMPXCHG
select ARCH_WANT_FRAME_POINTERS
select ARCH_CLOCKSOURCE_DATA
select ARCH_DISCARD_MEMBLOCK
select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
- select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
select ARCH_HAS_DEVMEM_IS_ALLOWED
select ARCH_HAS_ELF_RANDOMIZE
select ARCH_HAS_FAST_MULTIPLIER
config GENERIC_ATOMIC64
bool
-config ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
- def_bool y if GENERIC_ATOMIC64
-
config LRU_CACHE
tristate
r += one;
BUG_ON(v.counter != r);
-#ifdef CONFIG_ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
INIT(onestwos);
BUG_ON(atomic64_dec_if_positive(&v) != (onestwos - 1));
r -= one;
INIT(-one);
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 select the above Kconfig symbol
-#endif
INIT(onestwos);
BUG_ON(!atomic64_inc_not_zero(&v));
projects / kernel.git / commitdiff