Commit d55c5a93 authored by H. Peter Anvin's avatar H. Peter Anvin
Browse files

x86, 386 removal: Remove CONFIG_CMPXCHG 



All 486+ CPUs support CMPXCHG, so remove the fallback 386 support
code.

Signed-off-by: default avatarH. Peter Anvin <hpa@linux.intel.com>
Link: http://lkml.kernel.org/r/1354132230-21854-3-git-send-email-hpa@linux.intel.com
parent eb068e78

arch/x86/Kconfig.cpu

+0 −3
Original line number Diff line number Diff line
@@ -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

arch/x86/include/asm/cmpxchg_32.h

+0 −55
Original line number Diff line number Diff line
@@ -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

arch/x86/include/asm/percpu.h

+0 −3
Original line number Diff line number Diff line
@@ -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)		\

({									\

arch/x86/lib/Makefile

+0 −1
Original line number Diff line number Diff line
@@ -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

arch/x86/lib/cmpxchg.c

deleted100644 → 0
+0 −54
Original line number Diff line number Diff line 
/*

 * cmpxchg*() fallbacks for CPU not supporting these instructions

 */



#include <linux/kernel.h>

#include <linux/smp.h>

#include <linux/module.h>



#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