From 774400a3ba23b63f4de39e67ce6c4e48935809dc Mon Sep 17 00:00:00 2001 From: Thomas Petazzoni Date: Mon, 18 Aug 2008 12:33:21 +0200 Subject: [PATCH] x86: move cmpxchg fallbacks to a generic place arch/x86/kernel/cpu/intel.c defines a few fallback functions (cmpxchg_*()) that are used when the CPU doesn't support cmpxchg and/or cmpxchg64 natively. However, while defined in an Intel-specific file, these functions are also used for CPUs from other vendors when they don't support cmpxchg and/or cmpxchg64. This breaks the compilation when support for Intel CPUs is disabled. This patch moves these functions to a new arch/x86/kernel/cpu/cmpxchg.c file, unconditionally compiled when X86_32 is enabled. Signed-off-by: Thomas Petazzoni Cc: michael@free-electrons.com Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/Makefile | 2 +- arch/x86/kernel/cpu/cmpxchg.c | 72 +++++++++++++++++++++++++++++++++++ arch/x86/kernel/cpu/intel.c | 64 ------------------------------- 3 files changed, 73 insertions(+), 65 deletions(-) create mode 100644 arch/x86/kernel/cpu/cmpxchg.c diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile index ee76eaad3001..25b4c063fbf6 100644 --- a/arch/x86/kernel/cpu/Makefile +++ b/arch/x86/kernel/cpu/Makefile @@ -5,7 +5,7 @@ obj-y := intel_cacheinfo.o addon_cpuid_features.o obj-y += proc.o feature_names.o -obj-$(CONFIG_X86_32) += common.o bugs.o +obj-$(CONFIG_X86_32) += common.o bugs.o cmpxchg.o obj-$(CONFIG_X86_64) += common_64.o bugs_64.o obj-$(CONFIG_X86_32) += amd.o obj-$(CONFIG_X86_64) += amd_64.o diff --git a/arch/x86/kernel/cpu/cmpxchg.c b/arch/x86/kernel/cpu/cmpxchg.c new file mode 100644 index 000000000000..2056ccf572cc --- /dev/null +++ b/arch/x86/kernel/cpu/cmpxchg.c @@ -0,0 +1,72 @@ +/* + * cmpxchg*() fallbacks for CPU not supporting these instructions + */ + +#include +#include +#include + +#ifndef CONFIG_X86_CMPXCHG +unsigned long cmpxchg_386_u8(volatile void *ptr, u8 old, u8 new) +{ + u8 prev; + unsigned long flags; + + /* Poor man's cmpxchg for 386. Unsuitable for SMP */ + local_irq_save(flags); + prev = *(u8 *)ptr; + if (prev == old) + *(u8 *)ptr = new; + local_irq_restore(flags); + return prev; +} +EXPORT_SYMBOL(cmpxchg_386_u8); + +unsigned long cmpxchg_386_u16(volatile void *ptr, u16 old, u16 new) +{ + u16 prev; + unsigned long flags; + + /* Poor man's cmpxchg for 386. Unsuitable for SMP */ + local_irq_save(flags); + prev = *(u16 *)ptr; + if (prev == old) + *(u16 *)ptr = new; + local_irq_restore(flags); + return prev; +} +EXPORT_SYMBOL(cmpxchg_386_u16); + +unsigned long cmpxchg_386_u32(volatile void *ptr, u32 old, u32 new) +{ + u32 prev; + unsigned long flags; + + /* Poor man's cmpxchg for 386. Unsuitable for SMP */ + local_irq_save(flags); + prev = *(u32 *)ptr; + if (prev == old) + *(u32 *)ptr = new; + local_irq_restore(flags); + return prev; +} +EXPORT_SYMBOL(cmpxchg_386_u32); +#endif + +#ifndef CONFIG_X86_CMPXCHG64 +unsigned long long cmpxchg_486_u64(volatile void *ptr, u64 old, u64 new) +{ + u64 prev; + unsigned long flags; + + /* Poor man's cmpxchg8b for 386 and 486. Unsuitable for SMP */ + local_irq_save(flags); + prev = *(u64 *)ptr; + if (prev == old) + *(u64 *)ptr = new; + local_irq_restore(flags); + return prev; +} +EXPORT_SYMBOL(cmpxchg_486_u64); +#endif + diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c index 5c8959b8a42e..77618c717d76 100644 --- a/arch/x86/kernel/cpu/intel.c +++ b/arch/x86/kernel/cpu/intel.c @@ -307,69 +307,5 @@ static struct cpu_dev intel_cpu_dev __cpuinitdata = { cpu_vendor_dev_register(X86_VENDOR_INTEL, &intel_cpu_dev); -#ifndef CONFIG_X86_CMPXCHG -unsigned long cmpxchg_386_u8(volatile void *ptr, u8 old, u8 new) -{ - u8 prev; - unsigned long flags; - - /* Poor man's cmpxchg for 386. Unsuitable for SMP */ - local_irq_save(flags); - prev = *(u8 *)ptr; - if (prev == old) - *(u8 *)ptr = new; - local_irq_restore(flags); - return prev; -} -EXPORT_SYMBOL(cmpxchg_386_u8); - -unsigned long cmpxchg_386_u16(volatile void *ptr, u16 old, u16 new) -{ - u16 prev; - unsigned long flags; - - /* Poor man's cmpxchg for 386. Unsuitable for SMP */ - local_irq_save(flags); - prev = *(u16 *)ptr; - if (prev == old) - *(u16 *)ptr = new; - local_irq_restore(flags); - return prev; -} -EXPORT_SYMBOL(cmpxchg_386_u16); - -unsigned long cmpxchg_386_u32(volatile void *ptr, u32 old, u32 new) -{ - u32 prev; - unsigned long flags; - - /* Poor man's cmpxchg for 386. Unsuitable for SMP */ - local_irq_save(flags); - prev = *(u32 *)ptr; - if (prev == old) - *(u32 *)ptr = new; - local_irq_restore(flags); - return prev; -} -EXPORT_SYMBOL(cmpxchg_386_u32); -#endif - -#ifndef CONFIG_X86_CMPXCHG64 -unsigned long long cmpxchg_486_u64(volatile void *ptr, u64 old, u64 new) -{ - u64 prev; - unsigned long flags; - - /* Poor man's cmpxchg8b for 386 and 486. Unsuitable for SMP */ - local_irq_save(flags); - prev = *(u64 *)ptr; - if (prev == old) - *(u64 *)ptr = new; - local_irq_restore(flags); - return prev; -} -EXPORT_SYMBOL(cmpxchg_486_u64); -#endif - /* arch_initcall(intel_cpu_init); */ -- GitLab