From d55c5a93db2d5fa95f233ab153f594365d95b777 Mon Sep 17 00:00:00 2001 From: "H. Peter Anvin" Date: Wed, 28 Nov 2012 11:50:24 -0800 Subject: [PATCH] x86, 386 removal: Remove CONFIG_CMPXCHG All 486+ CPUs support CMPXCHG, so remove the fallback 386 support code. Signed-off-by: H. Peter Anvin Link: http://lkml.kernel.org/r/1354132230-21854-3-git-send-email-hpa@linux.intel.com --- arch/x86/Kconfig.cpu | 3 --- arch/x86/include/asm/cmpxchg_32.h | 55 --------------------------------------- arch/x86/include/asm/percpu.h | 3 --- arch/x86/lib/Makefile | 1 - arch/x86/lib/cmpxchg.c | 54 -------------------------------------- arch/x86/xen/Kconfig | 2 +- 6 files changed, 1 insertion(+), 117 deletions(-) delete mode 100644 arch/x86/lib/cmpxchg.c diff --git a/arch/x86/Kconfig.cpu b/arch/x86/Kconfig.cpu index 36a07eb..1290a69 100644 --- a/arch/x86/Kconfig.cpu +++ b/arch/x86/Kconfig.cpu @@ -297,9 +297,6 @@ config X86_INTERNODE_CACHE_SHIFT default "12" if X86_VSMP default X86_L1_CACHE_SHIFT -config X86_CMPXCHG - def_bool y - config X86_L1_CACHE_SHIFT int default "7" if MPENTIUM4 || MPSC diff --git a/arch/x86/include/asm/cmpxchg_32.h b/arch/x86/include/asm/cmpxchg_32.h index 53f4b21..f8bf2ee 100644 --- a/arch/x86/include/asm/cmpxchg_32.h +++ b/arch/x86/include/asm/cmpxchg_32.h @@ -34,9 +34,7 @@ static inline void set_64bit(volatile u64 *ptr, u64 value) : "memory"); } -#ifdef CONFIG_X86_CMPXCHG #define __HAVE_ARCH_CMPXCHG 1 -#endif #ifdef CONFIG_X86_CMPXCHG64 #define cmpxchg64(ptr, o, n) \ @@ -73,59 +71,6 @@ static inline u64 __cmpxchg64_local(volatile u64 *ptr, u64 old, u64 new) return prev; } -#ifndef CONFIG_X86_CMPXCHG -/* - * Building a kernel capable running on 80386. It may be necessary to - * simulate the cmpxchg on the 80386 CPU. For that purpose we define - * a function for each of the sizes we support. - */ - -extern unsigned long cmpxchg_386_u8(volatile void *, u8, u8); -extern unsigned long cmpxchg_386_u16(volatile void *, u16, u16); -extern unsigned long cmpxchg_386_u32(volatile void *, u32, u32); - -static inline unsigned long cmpxchg_386(volatile void *ptr, unsigned long old, - unsigned long new, int size) -{ - switch (size) { - case 1: - return cmpxchg_386_u8(ptr, old, new); - case 2: - return cmpxchg_386_u16(ptr, old, new); - case 4: - return cmpxchg_386_u32(ptr, old, new); - } - return old; -} - -#define cmpxchg(ptr, o, n) \ -({ \ - __typeof__(*(ptr)) __ret; \ - if (likely(boot_cpu_data.x86 > 3)) \ - __ret = (__typeof__(*(ptr)))__cmpxchg((ptr), \ - (unsigned long)(o), (unsigned long)(n), \ - sizeof(*(ptr))); \ - else \ - __ret = (__typeof__(*(ptr)))cmpxchg_386((ptr), \ - (unsigned long)(o), (unsigned long)(n), \ - sizeof(*(ptr))); \ - __ret; \ -}) -#define cmpxchg_local(ptr, o, n) \ -({ \ - __typeof__(*(ptr)) __ret; \ - if (likely(boot_cpu_data.x86 > 3)) \ - __ret = (__typeof__(*(ptr)))__cmpxchg_local((ptr), \ - (unsigned long)(o), (unsigned long)(n), \ - sizeof(*(ptr))); \ - else \ - __ret = (__typeof__(*(ptr)))cmpxchg_386((ptr), \ - (unsigned long)(o), (unsigned long)(n), \ - sizeof(*(ptr))); \ - __ret; \ -}) -#endif - #ifndef CONFIG_X86_CMPXCHG64 /* * Building a kernel capable running on 80386 and 80486. It may be necessary diff --git a/arch/x86/include/asm/percpu.h b/arch/x86/include/asm/percpu.h index 1104afa..0da5200 100644 --- a/arch/x86/include/asm/percpu.h +++ b/arch/x86/include/asm/percpu.h @@ -406,7 +406,6 @@ do { \ #define this_cpu_xchg_2(pcp, nval) percpu_xchg_op(pcp, nval) #define this_cpu_xchg_4(pcp, nval) percpu_xchg_op(pcp, nval) -#ifndef CONFIG_M386 #define __this_cpu_add_return_1(pcp, val) percpu_add_return_op(pcp, val) #define __this_cpu_add_return_2(pcp, val) percpu_add_return_op(pcp, val) #define __this_cpu_add_return_4(pcp, val) percpu_add_return_op(pcp, val) @@ -421,8 +420,6 @@ do { \ #define this_cpu_cmpxchg_2(pcp, oval, nval) percpu_cmpxchg_op(pcp, oval, nval) #define this_cpu_cmpxchg_4(pcp, oval, nval) percpu_cmpxchg_op(pcp, oval, nval) -#endif /* !CONFIG_M386 */ - #ifdef CONFIG_X86_CMPXCHG64 #define percpu_cmpxchg8b_double(pcp1, pcp2, o1, o2, n1, n2) \ ({ \ diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile index b00f678..96b2c66 100644 --- a/arch/x86/lib/Makefile +++ b/arch/x86/lib/Makefile @@ -32,7 +32,6 @@ ifeq ($(CONFIG_X86_32),y) lib-y += checksum_32.o lib-y += strstr_32.o lib-y += string_32.o - lib-y += cmpxchg.o ifneq ($(CONFIG_X86_CMPXCHG64),y) lib-y += cmpxchg8b_emu.o atomic64_386_32.o endif diff --git a/arch/x86/lib/cmpxchg.c b/arch/x86/lib/cmpxchg.c deleted file mode 100644 index 5d619f6d..0000000 --- a/arch/x86/lib/cmpxchg.c +++ /dev/null @@ -1,54 +0,0 @@ -/* - * 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 diff --git a/arch/x86/xen/Kconfig b/arch/x86/xen/Kconfig index fdce49c..9a6775c 100644 --- a/arch/x86/xen/Kconfig +++ b/arch/x86/xen/Kconfig @@ -7,7 +7,7 @@ config XEN select PARAVIRT select PARAVIRT_CLOCK depends on X86_64 || (X86_32 && X86_PAE && !X86_VISWS) - depends on X86_CMPXCHG && X86_TSC + depends on X86_TSC help This is the Linux Xen port. Enabling this will allow the kernel to boot in a paravirtualized environment under the -- 2.7.4