Commit c6dbd3e5 authored by Peter Zijlstra's avatar Peter Zijlstra
Browse files

x86/mmx_32: Remove X86_USE_3DNOW 



This code puts an exception table entry on the PREFETCH instruction to
overwrite it with a JMP.d8 when it triggers an exception. Except of
course, our code is no longer writable, also SMP.

Instead of fixing this broken mess, simply take it out.

Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: default avatarBorislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/YZKQzUmeNuwyvZpk@hirez.programming.kicks-ass.net
parent bff8c384

arch/x86/Kconfig

+1 −1
Original line number Diff line number Diff line
@@ -1957,7 +1957,7 @@ config EFI 


config EFI_STUB

	bool "EFI stub support"

	depends on EFI && !X86_USE_3DNOW

	depends on EFI

	depends on $(cc-option,-mabi=ms) || X86_32

	select RELOCATABLE

	help

arch/x86/Kconfig.cpu

+0 −4
Original line number Diff line number Diff line
@@ -342,10 +342,6 @@ config X86_USE_PPRO_CHECKSUM 
	def_bool y

	depends on MWINCHIP3D || MWINCHIPC6 || MCYRIXIII || MK7 || MK6 || MPENTIUM4 || MPENTIUMM || MPENTIUMIII || MPENTIUMII || M686 || MK8 || MVIAC3_2 || MVIAC7 || MEFFICEON || MGEODE_LX || MCORE2 || MATOM



config X86_USE_3DNOW

	def_bool y

	depends on (MCYRIXIII || MK7 || MGEODE_LX) && !UML



#

# P6_NOPs are a relatively minor optimization that require a family >=

# 6 processor, except that it is broken on certain VIA chips.

arch/x86/include/asm/mmx.h

+0 −15
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0 */

#ifndef _ASM_X86_MMX_H

#define _ASM_X86_MMX_H



/*

 *	MMX 3Dnow! helper operations

 */



#include <linux/types.h>



extern void *_mmx_memcpy(void *to, const void *from, size_t size);

extern void mmx_clear_page(void *page);

extern void mmx_copy_page(void *to, void *from);



#endif /* _ASM_X86_MMX_H */

arch/x86/include/asm/page_32.h

+0 −14
Original line number Diff line number Diff line
@@ -19,19 +19,6 @@ extern unsigned long __phys_addr(unsigned long); 
#define pfn_valid(pfn)		((pfn) < max_mapnr)

#endif /* CONFIG_FLATMEM */



#ifdef CONFIG_X86_USE_3DNOW

#include <asm/mmx.h>



static inline void clear_page(void *page)

{

	mmx_clear_page(page);

}



static inline void copy_page(void *to, void *from)

{

	mmx_copy_page(to, from);

}

#else  /* !CONFIG_X86_USE_3DNOW */

#include <linux/string.h>



static inline void clear_page(void *page)
@@ -43,7 +30,6 @@ static inline void copy_page(void *to, void *from) 
{

	memcpy(to, from, PAGE_SIZE);

}

#endif	/* CONFIG_X86_USE_3DNOW */

#endif	/* !__ASSEMBLY__ */



#endif /* _ASM_X86_PAGE_32_H */

arch/x86/include/asm/required-features.h

+0 −4
Original line number Diff line number Diff line
@@ -35,11 +35,7 @@ 
# define NEED_CMOV	0

#endif



#ifdef CONFIG_X86_USE_3DNOW

# define NEED_3DNOW	(1<<(X86_FEATURE_3DNOW & 31))

#else

# define NEED_3DNOW	0

#endif



#if defined(CONFIG_X86_P6_NOP) || defined(CONFIG_X86_64)

# define NEED_NOPL	(1<<(X86_FEATURE_NOPL & 31))