[PATCH v2 2/2] atomic64: No need for CONFIG_ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
From: Vineet Gupta <hidden>
Date: 2016-09-12 17:48:13
Also in:
linux-arch, linux-arm-kernel, linux-mips, linuxppc-dev, lkml, sparclinux
Subsystem:
alpha port, arm port, arm64 port (aarch64 architecture), library code, linux for powerpc (32-bit and 64-bit), mips, parisc architecture, s390 architecture, sparc + ultrasparc (sparc/sparc64), the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Richard Henderson, Matt Turner, Magnus Lindholm, Russell King, Catalin Marinas, Will Deacon, Andrew Morton, Madhavan Srinivasan, Michael Ellerman, Thomas Bogendoerfer, "James E.J. Bottomley", Helge Deller, Heiko Carstens, Vasily Gorbik, Alexander Gordeev, "David S. Miller", Andreas Larsson, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
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 Cc: Richard Henderson <redacted> Cc: Ivan Kokshaysky <redacted> Cc: Matt Turner <mattst88@gmail.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <redacted> Cc: Ralf Baechle <redacted> Cc: "James E.J. Bottomley" <redacted> Cc: Helge Deller <deller@gmx.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <redacted> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Martin Schwidefsky <redacted> Cc: Heiko Carstens <redacted> Cc: "David S. Miller" <davem@davemloft.net> Cc: Chris Metcalf <redacted> Cc: Thomas Gleixner <redacted> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: x86@kernel.org Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Vineet Gupta <redacted> Cc: Zhaoxiu Zeng <redacted> Cc: Linus Walleij <redacted> Cc: Matthew Wilcox <redacted> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <redacted> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Ming Lin <redacted> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Borislav Petkov <redacted> Cc: Andi Kleen <redacted> Cc: Boqun Feng <redacted> Cc: linux-alpha@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-mips@linux-mips.org Cc: linux-parisc@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: sparclinux@vger.kernel.org Cc: linux-snps-arc@lists.infradead.org Cc: linux-arch@vger.kernel.org Signed-off-by: Vineet Gupta <redacted> --- arch/alpha/Kconfig | 1 - arch/arm/Kconfig | 1 - arch/arm64/Kconfig | 1 - arch/mips/Kconfig | 1 - arch/parisc/Kconfig | 1 - arch/powerpc/Kconfig | 1 - arch/s390/Kconfig | 2 +- arch/sparc/Kconfig | 1 - arch/tile/Kconfig | 2 +- arch/x86/Kconfig | 2 +- lib/Kconfig | 3 --- lib/atomic64_test.c | 4 ---- 12 files changed, 3 insertions(+), 17 deletions(-)
diff --git a/arch/alpha/Kconfig b/arch/alpha/Kconfig
index 7f312d80b43b..0e49d39ea74a 100644
--- a/arch/alpha/Kconfig
+++ b/arch/alpha/Kconfig@@ -15,7 +15,6 @@ config ALPHA 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
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index a9c4e48bb7ec..2a50957c7bfb 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig@@ -1,7 +1,6 @@ config ARM bool default y - 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
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index bc3f00f586f1..3df2ca7efbcc 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig@@ -6,7 +6,6 @@ config ARM64 select ACPI_MCFG if ACPI 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_KCOV
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 26388562e300..5bbea197c220 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig@@ -30,7 +30,6 @@ config MIPS 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
diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig
index af12c2db9bb8..8a96bdcc3807 100644
--- a/arch/parisc/Kconfig
+++ b/arch/parisc/Kconfig@@ -14,7 +14,6 @@ config PARISC 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
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 927d2ab2ce08..18d1b42cf545 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig@@ -113,7 +113,6 @@ config PPC 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
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index c109f073d454..af52b07efde2 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig@@ -67,7 +67,7 @@ config DEBUG_RODATA config S390 def_bool y - select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE + select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS select ARCH_HAS_DEVMEM_IS_ALLOWED select ARCH_HAS_ELF_RANDOMIZE select ARCH_HAS_GCOV_PROFILE_ALL
diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index 59b09600dd32..bfedbe0cb7b2 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig@@ -22,7 +22,6 @@ config SPARC 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
diff --git a/arch/tile/Kconfig b/arch/tile/Kconfig
index 78da75b670bc..12eda5440c93 100644
--- a/arch/tile/Kconfig
+++ b/arch/tile/Kconfig@@ -3,7 +3,7 @@ config TILE def_bool y - select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE + select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS select ARCH_HAS_DEVMEM_IS_ALLOWED select ARCH_HAVE_NMI_SAFE_CMPXCHG select ARCH_WANT_FRAME_POINTERS
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 2a1f0ce7c59a..0cf609998550 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig@@ -23,7 +23,7 @@ config X86 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_DEBUG_STRICT_USER_COPY_CHECKS select ARCH_HAS_DEVMEM_IS_ALLOWED select ARCH_HAS_ELF_RANDOMIZE select ARCH_HAS_FAST_MULTIPLIER
diff --git a/lib/Kconfig b/lib/Kconfig
index d79909dc01ec..0e74df3c5441 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig@@ -457,9 +457,6 @@ config NLATTR config GENERIC_ATOMIC64 bool -config ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE - def_bool y if GENERIC_ATOMIC64 - config LRU_CACHE tristate
diff --git a/lib/atomic64_test.c b/lib/atomic64_test.c
index dbb369145dda..46042901130f 100644
--- a/lib/atomic64_test.c
+++ b/lib/atomic64_test.c@@ -213,7 +213,6 @@ static __init void test_atomic64(void) 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;
@@ -226,9 +225,6 @@ static __init void test_atomic64(void) 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));
--
2.7.4