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Message-Id: <1292482744-12953-2-git-send-email-ying.huang@intel.com>
Date: Thu, 16 Dec 2010 14:59:02 +0800
From: Huang Ying <ying.huang@...el.com>
To: Andrew Morton <akpm@...ux-foundation.org>
Cc: linux-kernel@...r.kernel.org, Andi Kleen <andi@...stfloor.org>,
ying.huang@...el.com, Peter Zijlstra <peterz@...radead.org>,
Linus Torvalds <torvalds@...ux-foundation.org>,
Ingo Molnar <mingo@...e.hu>,
Richard Henderson <rth@...ddle.net>,
Russell King <linux@....linux.org.uk>,
Mikael Starvik <starvik@...s.com>,
David Howells <dhowells@...hat.com>,
Yoshinori Sato <ysato@...rs.sourceforge.jp>,
Tony Luck <tony.luck@...el.com>,
Hirokazu Takata <takata@...ux-m32r.org>,
Geert Uytterhoeven <geert@...ux-m68k.org>,
Michal Simek <monstr@...str.eu>,
Ralf Baechle <ralf@...ux-mips.org>,
Kyle McMartin <kyle@...artin.ca>,
Martin Schwidefsky <schwidefsky@...ibm.com>,
Chen Liqin <liqin.chen@...plusct.com>,
"David S. Miller" <davem@...emloft.net>,
Ingo Molnar <mingo@...hat.com>, Chris Zankel <chris@...kel.net>
Subject: [PATCH -mm -v8 1/3] Add Kconfig option ARCH_HAVE_NMI_SAFE_CMPXCHG
cmpxchg() is widely used by lockless code, including NMI-safe lockless
code. But on some architectures, the cmpxchg() implementation is not
NMI-safe, on these architectures the lockless code may need to a
spin_trylock_irqsave() based implementation.
This patch adds a Kconfig option: ARCH_HAVE_NMI_SAFE_CMPXCHG, so that
NMI-safe lockless code can depend on it or provide different
implementation according to it.
On many architectures, cmpxchg is only NMI-safe for several specific
operand sizes. So, ARCH_HAVE_NMI_SAFE_CMPXCHG define in this patch
only guarantees cmpxchg is NMI-safe for sizeof(unsigned long).
Signed-off-by: Huang Ying <ying.huang@...el.com>
Acked-by: Mike Frysinger <vapier@...too.org>
Acked-by: Paul Mundt <lethal@...ux-sh.org>
Acked-by: Hans-Christian Egtvedt <hans-christian.egtvedt@...el.com>
Acked-by: Benjamin Herrenschmidt <benh@...nel.crashing.org>
Acked-by: Chris Metcalf <cmetcalf@...era.com>
CC: Richard Henderson <rth@...ddle.net>
CC: Russell King <linux@....linux.org.uk>
CC: Mikael Starvik <starvik@...s.com>
CC: David Howells <dhowells@...hat.com>
CC: Yoshinori Sato <ysato@...rs.sourceforge.jp>
CC: Tony Luck <tony.luck@...el.com>
CC: Hirokazu Takata <takata@...ux-m32r.org>
CC: Geert Uytterhoeven <geert@...ux-m68k.org>
CC: Michal Simek <monstr@...str.eu>
CC: Ralf Baechle <ralf@...ux-mips.org>
CC: Kyle McMartin <kyle@...artin.ca>
CC: Martin Schwidefsky <schwidefsky@...ibm.com>
CC: Chen Liqin <liqin.chen@...plusct.com>
CC: "David S. Miller" <davem@...emloft.net>
CC: Ingo Molnar <mingo@...hat.com>
CC: Chris Zankel <chris@...kel.net>
---
arch/Kconfig | 3 +++
arch/alpha/Kconfig | 1 +
arch/avr32/Kconfig | 1 +
arch/frv/Kconfig | 1 +
arch/ia64/Kconfig | 1 +
arch/m68k/Kconfig | 1 +
arch/parisc/Kconfig | 1 +
arch/powerpc/Kconfig | 1 +
arch/s390/Kconfig | 1 +
arch/sh/Kconfig | 1 +
arch/sparc/Kconfig | 1 +
arch/tile/Kconfig | 1 +
arch/x86/Kconfig | 1 +
13 files changed, 15 insertions(+), 0 deletions(-)
diff --git a/arch/Kconfig b/arch/Kconfig
index f78c2be..8dea68d 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -178,4 +178,7 @@ config HAVE_ARCH_JUMP_LABEL
config HAVE_ARCH_MUTEX_CPU_RELAX
bool
+config ARCH_HAVE_NMI_SAFE_CMPXCHG
+ bool
+
source "kernel/gcov/Kconfig"
diff --git a/arch/alpha/Kconfig b/arch/alpha/Kconfig
index 943fe69..4252a77 100644
--- a/arch/alpha/Kconfig
+++ b/arch/alpha/Kconfig
@@ -7,6 +7,7 @@ config ALPHA
select HAVE_SYSCALL_WRAPPERS
select HAVE_IRQ_WORK
select HAVE_PERF_EVENTS
+ select ARCH_HAVE_NMI_SAFE_CMPXCHG
select HAVE_DMA_ATTRS
help
The Alpha is a 64-bit general-purpose processor designed and
diff --git a/arch/avr32/Kconfig b/arch/avr32/Kconfig
index 313b130..1fc9bf8 100644
--- a/arch/avr32/Kconfig
+++ b/arch/avr32/Kconfig
@@ -6,6 +6,7 @@ config AVR32
select HAVE_CLK
select HAVE_OPROFILE
select HAVE_KPROBES
+ select ARCH_HAVE_NMI_SAFE_CMPXCHG
help
AVR32 is a high-performance 32-bit RISC microprocessor core,
designed for cost-sensitive embedded applications, with particular
diff --git a/arch/frv/Kconfig b/arch/frv/Kconfig
index 77deacd..01b5adb 100644
--- a/arch/frv/Kconfig
+++ b/arch/frv/Kconfig
@@ -5,6 +5,7 @@ config FRV
select HAVE_ARCH_TRACEHOOK
select HAVE_IRQ_WORK
select HAVE_PERF_EVENTS
+ select ARCH_HAVE_NMI_SAFE_CMPXCHG
config ZONE_DMA
bool
diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index e0f5b6d..2cacfa7 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -22,6 +22,7 @@ config IA64
select HAVE_KVM
select HAVE_ARCH_TRACEHOOK
select HAVE_DMA_API_DEBUG
+ select ARCH_HAVE_NMI_SAFE_CMPXCHG
default y
help
The Itanium Processor Family is Intel's 64-bit successor to
diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig
index bc9271b..8259bd1 100644
--- a/arch/m68k/Kconfig
+++ b/arch/m68k/Kconfig
@@ -4,6 +4,7 @@ config M68K
select HAVE_AOUT
select HAVE_IDE
select GENERIC_ATOMIC64
+ select ARCH_HAVE_NMI_SAFE_CMPXCHG if RMW_INSNS
config MMU
bool
diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig
index ca59250..79a3560 100644
--- a/arch/parisc/Kconfig
+++ b/arch/parisc/Kconfig
@@ -11,6 +11,7 @@ config PARISC
select BUG
select HAVE_IRQ_WORK
select HAVE_PERF_EVENTS
+ select ARCH_HAVE_NMI_SAFE_CMPXCHG
select GENERIC_ATOMIC64 if !64BIT
select GENERIC_HARDIRQS_NO__DO_IRQ
help
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 9d44ad3..56a57ea 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -145,6 +145,7 @@ config PPC
select GENERIC_ATOMIC64 if PPC32
select HAVE_IRQ_WORK
select HAVE_PERF_EVENTS
+ select ARCH_HAVE_NMI_SAFE_CMPXCHG
select HAVE_REGS_AND_STACK_ACCESS_API
select HAVE_HW_BREAKPOINT if PERF_EVENTS && PPC_BOOK3S_64
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index c05d081..d3ff45d 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -82,6 +82,7 @@ config S390
select INIT_ALL_POSSIBLE
select HAVE_IRQ_WORK
select HAVE_PERF_EVENTS
+ select ARCH_HAVE_NMI_SAFE_CMPXCHG
select HAVE_KERNEL_GZIP
select HAVE_KERNEL_BZIP2
select HAVE_KERNEL_LZMA
diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
index 84d8c87..a48f6fb 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig
@@ -11,6 +11,7 @@ config SUPERH
select HAVE_DMA_ATTRS
select HAVE_IRQ_WORK
select HAVE_PERF_EVENTS
+ select ARCH_HAVE_NMI_SAFE_CMPXCHG if (GUSA_RB || CPU_SH4A)
select PERF_USE_VMALLOC
select HAVE_KERNEL_GZIP
select HAVE_KERNEL_BZIP2
diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index af40adf..8b70990 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -22,6 +22,7 @@ config SPARC
select RTC_CLASS
select RTC_DRV_M48T59
select HAVE_IRQ_WORK
+ select ARCH_HAVE_NMI_SAFE_CMPXCHG
select HAVE_DMA_ATTRS
select HAVE_DMA_API_DEBUG
select HAVE_ARCH_JUMP_LABEL
diff --git a/arch/tile/Kconfig b/arch/tile/Kconfig
index e11b5fc..b8ebec6 100644
--- a/arch/tile/Kconfig
+++ b/arch/tile/Kconfig
@@ -104,6 +104,7 @@ config TILE
select GENERIC_FIND_NEXT_BIT
select USE_GENERIC_SMP_HELPERS
select CC_OPTIMIZE_FOR_SIZE
+ select ARCH_HAVE_NMI_SAFE_CMPXCHG
# FIXME: investigate whether we need/want these options.
# select HAVE_IOREMAP_PROT
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index fe0bdb4..1b01117 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -23,6 +23,7 @@ config X86
select HAVE_OPROFILE
select HAVE_PERF_EVENTS
select HAVE_IRQ_WORK
+ select ARCH_HAVE_NMI_SAFE_CMPXCHG if !M386
select HAVE_IOREMAP_PROT
select HAVE_KPROBES
select HAVE_MEMBLOCK
--
1.7.2.3
--
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