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Commit 84f3fb7a authored by Greg Ungerer's avatar Greg Ungerer
Browse files

m68k: handle presence of 64bit mul/div instructions cleanly 



The traditional 68000 processors and the newer reduced instruction set
ColdFire processors do not support the 32*32->64 multiply or the 64/32->32
divide instructions. This is not a difference based on the presence of
a hardware MMU or not.

Create a new config symbol to mark that a CPU type doesn't support the
longer multiply/divide instructions. Use this then as a basis for using
the fast 64bit based divide (in div64.h) and for linking in the extra
libgcc functions that may be required (mulsi3, divsi3, etc).

Signed-off-by: default avatarGreg Ungerer <gerg@uclinux.org>
Acked-by: default avatarGeert Uytterhoeven <geert@linux-m68k.org>
parent 7f73bafc

arch/m68k/Kconfig

+3 −0
Original line number Diff line number Diff line
@@ -63,6 +63,9 @@ config ZONE_DMA 
config CPU_HAS_NO_BITFIELDS

	bool



config CPU_HAS_NO_MULDIV64

	bool



config HZ

	int

	default 1000 if CLEOPATRA

arch/m68k/Kconfig.cpu

+2 −0
Original line number Diff line number Diff line
@@ -3,6 +3,7 @@ comment "Processor Type" 
config M68000

	bool

	select CPU_HAS_NO_BITFIELDS

	select CPU_HAS_NO_MULDIV64

	select GENERIC_CSUM

	help

	  The Freescale (was Motorola) 68000 CPU is the first generation of
@@ -24,6 +25,7 @@ config COLDFIRE 
	select GENERIC_GPIO

	select ARCH_REQUIRE_GPIOLIB

	select CPU_HAS_NO_BITFIELDS

	select CPU_HAS_NO_MULDIV64

	select GENERIC_CSUM

	help

	  The Freescale ColdFire family of processors is a modern derivitive

arch/m68k/include/asm/div64.h

+4 −4
Original line number Diff line number Diff line 
#ifndef _M68K_DIV64_H

#define _M68K_DIV64_H



#ifdef CONFIG_MMU

#ifdef CONFIG_CPU_HAS_NO_MULDIV64

#include <asm-generic/div64.h>

#else



#include <linux/types.h>
@@ -27,8 +29,6 @@ 
	__rem;							\

})



#else

#include <asm-generic/div64.h>

#endif /* CONFIG_MMU */

#endif /* CONFIG_CPU_HAS_NO_MULDIV64 */



#endif /* _M68K_DIV64_H */

arch/m68k/kernel/m68k_ksyms.c

+1 −1
Original line number Diff line number Diff line
@@ -14,7 +14,7 @@ EXPORT_SYMBOL(__ashrdi3); 
EXPORT_SYMBOL(__lshrdi3);

EXPORT_SYMBOL(__muldi3);



#if defined(CONFIG_M68000) || defined(CONFIG_COLDFIRE)

#if defined(CONFIG_CPU_HAS_NO_MULDIV64)

/*

 * Simpler 68k and ColdFire parts also need a few other gcc functions.

 */

arch/m68k/lib/Makefile

+3 −5
Original line number Diff line number Diff line
@@ -6,11 +6,9 @@ 
lib-y	:= ashldi3.o ashrdi3.o lshrdi3.o muldi3.o \

	   memcpy.o memset.o memmove.o



ifdef CONFIG_MMU

lib-y	+= string.o uaccess.o

else

lib-y	+= mulsi3.o divsi3.o udivsi3.o modsi3.o umodsi3.o

endif

lib-$(CONFIG_MMU) += string.o uaccess.o

lib-$(CONFIG_CPU_HAS_NO_MULDIV64) += mulsi3.o divsi3.o udivsi3.o

lib-$(CONFIG_CPU_HAS_NO_MULDIV64) += modsi3.o umodsi3.o



ifndef CONFIG_GENERIC_CSUM

lib-y	+= checksum.o