[PATCH 10/19] Add Kconfig option ARCH_HAVE_NMI_SAFE_CMPXCHG

From: Len Brown
Date: Tue Aug 02 2011 - 18:52:31 EST

Next message: Len Brown: "[PATCH 13/19] ACPI, APEI, GHES,printk support for recoverable error via NMI"
Previous message: Len Brown: "[PATCH 15/19] HWPoison: add memory_failure_queue()"
In reply to: Len Brown: "[PATCH 15/19] HWPoison: add memory_failure_queue()"
Next in thread: Ralf Baechle: "Re: [PATCH 10/19] Add Kconfig option ARCH_HAVE_NMI_SAFE_CMPXCHG"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

From: Huang Ying <ying.huang@xxxxxxxxx>

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 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@xxxxxxxxx>
Acked-by: Mike Frysinger <vapier@xxxxxxxxxx>
Acked-by: Paul Mundt <lethal@xxxxxxxxxxxx>
Acked-by: Hans-Christian Egtvedt <hans-christian.egtvedt@xxxxxxxxx>
Acked-by: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Acked-by: Chris Metcalf <cmetcalf@xxxxxxxxxx>
CC: Richard Henderson <rth@xxxxxxxxxxx>
CC: Mikael Starvik <starvik@xxxxxxxx>
CC: David Howells <dhowells@xxxxxxxxxx>
CC: Yoshinori Sato <ysato@xxxxxxxxxxxxxxxxxxxx>
CC: Tony Luck <tony.luck@xxxxxxxxx>
CC: Hirokazu Takata <takata@xxxxxxxxxxxxxx>
CC: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
CC: Michal Simek <monstr@xxxxxxxxx>
CC: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
CC: Kyle McMartin <kyle@xxxxxxxxxxx>
CC: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
CC: Chen Liqin <liqin.chen@xxxxxxxxxxxxx>
CC: "David S. Miller" <davem@xxxxxxxxxxxxx>
CC: Ingo Molnar <mingo@xxxxxxxxxx>
CC: Chris Zankel <chris@xxxxxxxxxx>
Signed-off-by: Len Brown <len.brown@xxxxxxxxx>
---
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 26b0e23..4b0669c 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -178,4 +178,7 @@ config HAVE_ARCH_MUTEX_CPU_RELAX
config HAVE_RCU_TABLE_FREE
bool

+config ARCH_HAVE_NMI_SAFE_CMPXCHG
+ bool
+
source "kernel/gcov/Kconfig"
diff --git a/arch/alpha/Kconfig b/arch/alpha/Kconfig
index 60219bf..23f8d8c 100644
--- a/arch/alpha/Kconfig
+++ b/arch/alpha/Kconfig
@@ -13,6 +13,7 @@ config ALPHA
select AUTO_IRQ_AFFINITY if SMP
select GENERIC_IRQ_SHOW
select ARCH_WANT_OPTIONAL_GPIOLIB
+ select ARCH_HAVE_NMI_SAFE_CMPXCHG
help
The Alpha is a 64-bit general-purpose processor designed and
marketed by the Digital Equipment Corporation of blessed memory,
diff --git a/arch/avr32/Kconfig b/arch/avr32/Kconfig
index e9d689b..197e96f 100644
--- a/arch/avr32/Kconfig
+++ b/arch/avr32/Kconfig
@@ -10,6 +10,7 @@ config AVR32
select GENERIC_IRQ_PROBE
select HARDIRQS_SW_RESEND
select GENERIC_IRQ_SHOW
+ 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 cb884e4..bad27a6 100644
--- a/arch/frv/Kconfig
+++ b/arch/frv/Kconfig
@@ -7,6 +7,7 @@ config FRV
select HAVE_PERF_EVENTS
select HAVE_GENERIC_HARDIRQS
select GENERIC_IRQ_SHOW
+ select ARCH_HAVE_NMI_SAFE_CMPXCHG

config ZONE_DMA
bool
diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index 38280ef..b1227dd 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -27,6 +27,7 @@ config IA64
select GENERIC_PENDING_IRQ if SMP
select IRQ_PER_CPU
select GENERIC_IRQ_SHOW
+ 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 d66e34c..effe8f0 100644
--- a/arch/m68k/Kconfig
+++ b/arch/m68k/Kconfig
@@ -6,6 +6,7 @@ config M68K
select GENERIC_ATOMIC64 if MMU
select HAVE_GENERIC_HARDIRQS if !MMU
select GENERIC_IRQ_SHOW if !MMU
+ select ARCH_HAVE_NMI_SAFE_CMPXCHG if RMW_INSNS

config RWSEM_GENERIC_SPINLOCK
bool
diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig
index 65adc86..e077b0b 100644
--- a/arch/parisc/Kconfig
+++ b/arch/parisc/Kconfig
@@ -15,6 +15,7 @@ config PARISC
select HAVE_GENERIC_HARDIRQS
select GENERIC_IRQ_PROBE
select IRQ_PER_CPU
+ select ARCH_HAVE_NMI_SAFE_CMPXCHG

help
The PA-RISC microprocessor is designed by Hewlett-Packard and used
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 2729c66..e55f754 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -134,6 +134,7 @@ config PPC
select GENERIC_IRQ_SHOW_LEVEL
select HAVE_RCU_TABLE_FREE if SMP
select HAVE_SYSCALL_TRACEPOINTS
+ select ARCH_HAVE_NMI_SAFE_CMPXCHG

config EARLY_PRINTK
bool
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index c03fef7..0f98bbd 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -81,6 +81,7 @@ 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 bbdeb48..66405eb 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 253986b..a63cddf 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -53,6 +53,7 @@ config SPARC64
select HAVE_PERF_EVENTS
select PERF_USE_VMALLOC
select IRQ_PREFLOW_FASTEOI
+ select ARCH_HAVE_NMI_SAFE_CMPXCHG

config ARCH_DEFCONFIG
string
diff --git a/arch/tile/Kconfig b/arch/tile/Kconfig
index 0249b8b..b30f71a 100644
--- a/arch/tile/Kconfig
+++ b/arch/tile/Kconfig
@@ -12,6 +12,7 @@ config TILE
select GENERIC_PENDING_IRQ if SMP
select GENERIC_IRQ_SHOW
select SYS_HYPERVISOR
+ select ARCH_HAVE_NMI_SAFE_CMPXCHG if !M386

# FIXME: investigate whether we need/want these options.
# select HAVE_IOREMAP_PROT
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index da34972..a680a60 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -70,6 +70,7 @@ config X86
select IRQ_FORCED_THREADING
select USE_GENERIC_SMP_HELPERS if SMP
select HAVE_BPF_JIT if (X86_64 && NET)
+ select ARCH_HAVE_NMI_SAFE_CMPXCHG

config INSTRUCTION_DECODER
def_bool (KPROBES || PERF_EVENTS)
--
1.7.6.396.ge0613

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

Next message: Len Brown: "[PATCH 13/19] ACPI, APEI, GHES,printk support for recoverable error via NMI"
Previous message: Len Brown: "[PATCH 15/19] HWPoison: add memory_failure_queue()"
In reply to: Len Brown: "[PATCH 15/19] HWPoison: add memory_failure_queue()"
Next in thread: Ralf Baechle: "Re: [PATCH 10/19] Add Kconfig option ARCH_HAVE_NMI_SAFE_CMPXCHG"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]