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authorWill Deacon <will.deacon@arm.com>2012-07-06 15:45:39 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2012-07-09 17:41:11 +0100
commit8c56cc8be5b38e3684eba96dc9b3f7ca7e495755 (patch)
treeeccb882c8c5f1cc81fc226c769fc9ec99a45145b /arch/arm/Kconfig
parent4295b898f5a5c7e62ae68e7a4ecc4b414622ffe6 (diff)
ARM: 7449/1: use generic strnlen_user and strncpy_from_user functions
This patch implements the word-at-a-time interface for ARM using the same algorithm as x86. We use the fls macro from ARMv5 onwards, where we have a clz instruction available which saves us a mov instruction when targetting Thumb-2. For older CPUs, we use the magic 0x0ff0001 constant. Big-endian configurations make use of the implementation from asm-generic. With this implemented, we can replace our byte-at-a-time strnlen_user and strncpy_from_user functions with the optimised generic versions. Reviewed-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/Kconfig')
-rw-r--r--arch/arm/Kconfig2
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 8c9d264f210..574561a66d7 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -46,6 +46,8 @@ config ARM
select GENERIC_SMP_IDLE_THREAD
select KTIME_SCALAR
select GENERIC_CLOCKEVENTS_BROADCAST if SMP
+ select GENERIC_STRNCPY_FROM_USER
+ select GENERIC_STRNLEN_USER
help
The ARM series is a line of low-power-consumption RISC chip designs
licensed by ARM Ltd and targeted at embedded applications and