[PATCH] ARM: fix modular build of xor_blocks() with NEON enabled

[Ard Biesheuvel]

Commit 0195659 introduced a NEON accelerated version of the xor_blocks()
function, but it needs the changes in this patch to allow it to be built
as a module rather than statically into the kernel.

This patch creates a separate module xor-neon.ko which exports the NEON
inner xor_blocks() functions depended upon by the regular xor.ko if it
is built with CONFIG_KERNEL_MODE_NEON=y

Reported-by: Josh Boyer <jwboyer at fedoraproject.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel at linaro.org>
---
 arch/arm/lib/Makefile   | 4 +++-
 arch/arm/lib/xor-neon.c | 4 ++++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/arch/arm/lib/Makefile b/arch/arm/lib/Makefile
index aaf3a87..6bc2bd3 100644
--- a/arch/arm/lib/Makefile
+++ b/arch/arm/lib/Makefile
@@ -49,5 +49,7 @@ $(obj)/csumpartialcopyuser.o:	$(obj)/csumpartialcopygeneric.S
 ifeq ($(CONFIG_KERNEL_MODE_NEON),y)
   NEON_FLAGS			:= -mfloat-abi=softfp -mfpu=neon
   CFLAGS_xor-neon.o		+= $(NEON_FLAGS)
-  lib-$(CONFIG_XOR_BLOCKS)	+= xor-neon.o
+  xor-neon-$(CONFIG_XOR_BLOCKS)	:= xor-neon.o
+  lib-y				+= $(xor-neon-y)
+  obj-m				+= $(xor-neon-m)
 endif
diff --git a/arch/arm/lib/xor-neon.c b/arch/arm/lib/xor-neon.c
index f485e5a..2c40aea 100644
--- a/arch/arm/lib/xor-neon.c
+++ b/arch/arm/lib/xor-neon.c
@@ -9,6 +9,9 @@
  */
 
 #include <linux/raid/xor.h>
+#include <linux/module.h>
+
+MODULE_LICENSE("GPL");
 
 #ifndef __ARM_NEON__
 #error You should compile this file with '-mfloat-abi=softfp -mfpu=neon'
@@ -40,3 +43,4 @@ struct xor_block_template const xor_block_neon_inner = {
 	.do_4	= xor_8regs_4,
 	.do_5	= xor_8regs_5,
 };
+EXPORT_SYMBOL(xor_block_neon_inner);
-- 
1.8.1.2