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Commit 19d402c1 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branches 'x86-build-for-linus', 'x86-cleanups-for-linus' and... 

Merge branches 'x86-build-for-linus', 'x86-cleanups-for-linus' and 'x86-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 build/cleanup/debug updates from Ingo Molnar:
 "Robustify the build process with a quirk to avoid GCC reordering
  related bugs.

  Two code cleanups.

  Simplify entry_64.S CFI annotations, by Jan Beulich"

* 'x86-build-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, build: Change code16gcc.h from a C header to an assembly header

* 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86: Simplify __HAVE_ARCH_CMPXCHG tests
  x86/tsc: Get rid of custom DIV_ROUND() macro

* 'x86-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/debug: Drop several unnecessary CFI annotations
parents 98959948 a9cfccee b08ee5f7 3bab13b0

arch/x86/Makefile

+3 −6
Original line number Diff line number Diff line
@@ -15,12 +15,9 @@ endif 
# that way we can complain to the user if the CPU is insufficient.

#

# The -m16 option is supported by GCC >= 4.9 and clang >= 3.5. For

# older versions of GCC, we need to play evil and unreliable tricks to

# attempt to ensure that our asm(".code16gcc") is first in the asm

# output.

CODE16GCC_CFLAGS := -m32 -include $(srctree)/arch/x86/boot/code16gcc.h \

		    $(call cc-option, -fno-toplevel-reorder,\

		      $(call cc-option, -fno-unit-at-a-time))

# older versions of GCC, include an *assembly* header to make sure that

# gcc doesn't play any games behind our back.

CODE16GCC_CFLAGS := -m32 -Wa,$(srctree)/arch/x86/boot/code16gcc.h

M16_CFLAGS	 := $(call cc-option, -m16, $(CODE16GCC_CFLAGS))



REALMODE_CFLAGS	:= $(M16_CFLAGS) -g -Os -D__KERNEL__ \

arch/x86/boot/code16gcc.h

+10 −14
Original line number Diff line number Diff line 
/*

 * code16gcc.h

 *

 * This file is -include'd when compiling 16-bit C code.

 * Note: this asm() needs to be emitted before gcc emits any code.

 * Depending on gcc version, this requires -fno-unit-at-a-time or

 * -fno-toplevel-reorder.

 *

 * Hopefully gcc will eventually have a real -m16 option so we can

 * drop this hack long term.

 */

#

# code16gcc.h

#

# This file is added to the assembler via -Wa when compiling 16-bit C code.

# This is done this way instead via asm() to make sure gcc does not reorder

# things around us.

#

# gcc 4.9+ has a real -m16 option so we can drop this hack long term.

#



#ifndef __ASSEMBLY__

asm(".code16gcc");

#endif
 
	.code16gcc

arch/x86/include/asm/cmpxchg.h

+2 −2
Original line number Diff line number Diff line
@@ -4,6 +4,8 @@ 
#include <linux/compiler.h>

#include <asm/alternative.h> /* Provides LOCK_PREFIX */



#define __HAVE_ARCH_CMPXCHG 1



/*

 * Non-existant functions to indicate usage errors at link time

 * (or compile-time if the compiler implements __compiletime_error().
@@ -143,7 +145,6 @@ extern void __add_wrong_size(void) 
# include <asm/cmpxchg_64.h>

#endif



#ifdef __HAVE_ARCH_CMPXCHG

#define cmpxchg(ptr, old, new)						\

	__cmpxchg(ptr, old, new, sizeof(*(ptr)))
@@ -152,7 +153,6 @@ extern void __add_wrong_size(void) 


#define cmpxchg_local(ptr, old, new)					\

	__cmpxchg_local(ptr, old, new, sizeof(*(ptr)))

#endif



/*

 * xadd() adds "inc" to "*ptr" and atomically returns the previous

arch/x86/include/asm/cmpxchg_32.h

+0 −2
Original line number Diff line number Diff line
@@ -34,8 +34,6 @@ static inline void set_64bit(volatile u64 *ptr, u64 value) 
		     : "memory");

}



#define __HAVE_ARCH_CMPXCHG 1



#ifdef CONFIG_X86_CMPXCHG64

#define cmpxchg64(ptr, o, n)						\

	((__typeof__(*(ptr)))__cmpxchg64((ptr), (unsigned long long)(o), \

arch/x86/include/asm/cmpxchg_64.h

+0 −2
Original line number Diff line number Diff line
@@ -6,8 +6,6 @@ static inline void set_64bit(volatile u64 *ptr, u64 val) 
	*ptr = val;

}



#define __HAVE_ARCH_CMPXCHG 1



#define cmpxchg64(ptr, o, n)						\

({									\

	BUILD_BUG_ON(sizeof(*(ptr)) != 8);				\