Commit cb601185 authored by Will Deacon's avatar Will Deacon Committed by Russell King
Browse files

ARM: 7927/1: dcache: select DCACHE_WORD_ACCESS for big-endian CPUs 



With commit 11ec50ca ("word-at-a-time: provide generic big-endian
zero_bytemask implementation"), the asm-generic word-at-a-time code now
provides a zero_bytemask implementation, allowing us to make use of
DCACHE_WORD_ACCESS on big-endian CPUs, providing our
load_unaligned_zeropad function is endianness-clean.

This patch reworks the load_unaligned_zeropad fixup code to work for
both big- and little-endian CPUs, then removes the !CPU_BIG_ENDIAN check
when selecting DCACHE_WORD_ACCESS.

Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 5d497509

arch/arm/Kconfig

+1 −1
Original line number Diff line number Diff line
@@ -12,7 +12,7 @@ config ARM 
	select BUILDTIME_EXTABLE_SORT if MMU

	select CLONE_BACKWARDS

	select CPU_PM if (SUSPEND || CPU_IDLE)

	select DCACHE_WORD_ACCESS if (CPU_V6 || CPU_V6K || CPU_V7) && !CPU_BIG_ENDIAN && MMU

	select DCACHE_WORD_ACCESS if (CPU_V6 || CPU_V6K || CPU_V7) && MMU

	select GENERIC_ATOMIC64 if (CPU_V7M || CPU_V6 || !CPU_32v6K || !AEABI)

	select GENERIC_CLOCKEVENTS_BROADCAST if SMP

	select GENERIC_IDLE_POLL_SETUP

arch/arm/include/asm/word-at-a-time.h

+10 −8
Original line number Diff line number Diff line
@@ -48,10 +48,14 @@ static inline unsigned long find_zero(unsigned long mask) 
	return ret;

}



#ifdef CONFIG_DCACHE_WORD_ACCESS



#define zero_bytemask(mask) (mask)



#else	/* __ARMEB__ */

#include <asm-generic/word-at-a-time.h>

#endif



#ifdef CONFIG_DCACHE_WORD_ACCESS



/*

 * Load an unaligned word from kernel space.

 *
@@ -73,7 +77,11 @@ static inline unsigned long load_unaligned_zeropad(const void *addr) 
	"	bic	%2, %2, #0x3\n"

	"	ldr	%0, [%2]\n"

	"	lsl	%1, %1, #0x3\n"

#ifndef __ARMEB__

	"	lsr	%0, %0, %1\n"

#else

	"	lsl	%0, %0, %1\n"

#endif

	"	b	2b\n"

	"	.popsection\n"

	"	.pushsection __ex_table,\"a\"\n"
@@ -86,11 +94,5 @@ static inline unsigned long load_unaligned_zeropad(const void *addr) 
	return ret;

}





#endif	/* DCACHE_WORD_ACCESS */



#else	/* __ARMEB__ */

#include <asm-generic/word-at-a-time.h>

#endif



#endif /* __ASM_ARM_WORD_AT_A_TIME_H */

CRA Git | Maintained and supported by SUSTech CRA and CCSE