ARM: Bring back ARMv3 IO and user access code

This partially reverts 357c9c1f07d4546bc3fbc0fd1044d96b114d14ed
(ARM: Remove support for ARMv3 ARM610 and ARM710 CPUs).

Although we only support StrongARM on the RiscPC, we need to keep the
ARMv3 user access code for this platform because the bus does not
understand half-word load/stores.

Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 20 insertions, 3 deletions

diff --git a/arch/arm/lib/Makefile b/arch/arm/lib/Makefile
index 2473fd1fd51c..af72969820b4 100644
--- a/arch/arm/lib/Makefile
+++ b/arch/arm/lib/Makefile
@@ -16,13 +16,30 @@ lib-y		:= backtrace.o changebit.o csumipv6.o csumpartial.o   \
 		   call_with_stack.o
 
 mmu-y	:= clear_user.o copy_page.o getuser.o putuser.o
-mmu-y	+= copy_from_user.o copy_to_user.o
+
+# the code in uaccess.S is not preemption safe and
+# probably faster on ARMv3 only
+ifeq ($(CONFIG_PREEMPT),y)
+  mmu-y	+= copy_from_user.o copy_to_user.o
+else
+ifneq ($(CONFIG_CPU_32v3),y)
+  mmu-y	+= copy_from_user.o copy_to_user.o
+else
+  mmu-y	+= uaccess.o
+endif
+endif
 
 # using lib_ here won't override already available weak symbols
 obj-$(CONFIG_UACCESS_WITH_MEMCPY) += uaccess_with_memcpy.o
 
-lib-$(CONFIG_MMU)		+= $(mmu-y)
-lib-y				+= io-readsw-armv4.o io-writesw-armv4.o
+lib-$(CONFIG_MMU) += $(mmu-y)
+
+ifeq ($(CONFIG_CPU_32v3),y)
+  lib-y	+= io-readsw-armv3.o io-writesw-armv3.o
+else
+  lib-y	+= io-readsw-armv4.o io-writesw-armv4.o
+endif
+
 lib-$(CONFIG_ARCH_RPC)		+= ecard.o io-acorn.o floppydma.o
 lib-$(CONFIG_ARCH_SHARK)	+= io-shark.o