From df013ffb8119c89f062ab05b7f544704315db47b Mon Sep 17 00:00:00 2001 From: Huang Ying Date: Wed, 13 Jul 2011 13:14:22 +0800 Subject: [PATCH] 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 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 Acked-by: Mike Frysinger Acked-by: Paul Mundt Acked-by: Hans-Christian Egtvedt Acked-by: Benjamin Herrenschmidt Acked-by: Chris Metcalf Acked-by: Richard Henderson CC: Mikael Starvik Acked-by: David Howells CC: Yoshinori Sato CC: Tony Luck CC: Hirokazu Takata CC: Geert Uytterhoeven CC: Michal Simek Acked-by: Ralf Baechle CC: Kyle McMartin CC: Martin Schwidefsky CC: Chen Liqin CC: "David S. Miller" CC: Ingo Molnar CC: Chris Zankel Signed-off-by: Len Brown --- 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(+) diff --git a/arch/Kconfig b/arch/Kconfig index 26b0e2397a57..4b0669cbb3b0 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 60219bf94198..23f8d8c32886 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 e9d689b7c833..197e96f70405 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 cb884e489425..bad27a6ff407 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 38280ef4a2af..b1227ddc672a 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 d66e34c718d0..effe8f0fa31e 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 65adc86a230e..e077b0bf56ca 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 2729c6663d8a..e55f754dd50d 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 c03fef7a9c22..0f98bbddade5 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 bbdeb48bbf8e..66405eb21766 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 253986bd6bb6..a63cddfb3a15 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 0249b8b4db54..b30f71ac0d06 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 da349723d411..a680a60898de 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) -- GitLab