[PATCH 11/26] arm: move the XOR code to lib/raid/

Christoph Hellwig
2026-03-24T06:25:07Z

Move the optimized XOR into lib/raid and include it it in the main
xor.ko instead of building a separate module for it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
arch/arm/include/asm/xor.h | 190 +-----------------
arch/arm/lib/Makefile | 5 -
lib/raid/xor/Makefile | 8 +
lib/raid/xor/arm/xor-neon-glue.c | 58 ++++++
{arch/arm/lib => lib/raid/xor/arm}/xor-neon.c | 10 +-
lib/raid/xor/arm/xor.c | 136 +++++++++++++
6 files changed, 205 insertions(+), 202 deletions(-)
create mode 100644 lib/raid/xor/arm/xor-neon-glue.c
rename {arch/arm/lib => lib/raid/xor/arm}/xor-neon.c (74%)
create mode 100644 lib/raid/xor/arm/xor.c

diff --git a/arch/arm/include/asm/xor.h b/arch/arm/include/asm/xor.h
index b2dcd49186e2..989c55872ef6 100644
--- a/arch/arm/include/asm/xor.h
+++ b/arch/arm/include/asm/xor.h
@@ -1,198 +1,12 @@
/* SPDX-License-Identifier: GPL-2.0-only */
/*
- * arch/arm/include/asm/xor.h
- *
* Copyright (C) 2001 Russell King
*/
#include <asm-generic/xor.h>
-#include <asm/hwcap.h>
#include <asm/neon.h>

-#define __XOR(a1, a2) a1 ^= a2
-
-#define GET_BLOCK_2(dst) \
- __asm__("ldmia %0, {%1, %2}" \
- : "=r" (dst), "=r" (a1), "=r" (a2) \
- : "0" (dst))
-
-#define GET_BLOCK_4(dst) \
- __asm__("ldmia %0, {%1, %2, %3, %4}" \
- : "=r" (dst), "=r" (a1), "=r" (a2), "=r" (a3), "=r" (a4) \
- : "0" (dst))
-
-#define XOR_BLOCK_2(src) \
- __asm__("ldmia %0!, {%1, %2}" \
- : "=r" (src), "=r" (b1), "=r" (b2) \
- : "0" (src)); \
- __XOR(a1, b1); __XOR(a2, b2);
-
-#define XOR_BLOCK_4(src) \
- __asm__("ldmia %0!, {%1, %2, %3, %4}" \
- : "=r" (src), "=r" (b1), "=r" (b2), "=r" (b3), "=r" (b4) \
- : "0" (src)); \
- __XOR(a1, b1); __XOR(a2, b2); __XOR(a3, b3); __XOR(a4, b4)
-
-#define PUT_BLOCK_2(dst) \
- __asm__ __volatile__("stmia %0!, {%2, %3}" \
- : "=r" (dst) \
- : "0" (dst), "r" (a1), "r" (a2))
-
-#define PUT_BLOCK_4(dst) \
- __asm__ __volatile__("stmia %0!, {%2, %3, %4, %5}" \
- : "=r" (dst) \
- : "0" (dst), "r" (a1), "r" (a2), "r" (a3), "r" (a4))
-
-static void
-xor_arm4regs_2(unsigned long bytes, unsigned long * __restrict p1,
- const unsigned long * __restrict p2)
-{
- unsigned int lines = bytes / sizeof(unsigned long) / 4;
- register unsigned int a1 __asm__("r4");
- register unsigned int a2 __asm__("r5");
- register unsigned int a3 __asm__("r6");
- register unsigned int a4 __asm__("r10");
- register unsigned int b1 __asm__("r8");
- register unsigned int b2 __asm__("r9");
- register unsigned int b3 __asm__("ip");
- register unsigned int b4 __asm__("lr");
-
- do {
- GET_BLOCK_4(p1);
- XOR_BLOCK_4(p2);
- PUT_BLOCK_4(p1);
- } while (--lines);
-}
-
-static void
-xor_arm4regs_3(unsigned long bytes, unsigned long * __restrict p1,
- const unsigned long * __restrict p2,
- const unsigned long * __restrict p3)
-{
- unsigned int lines = bytes / sizeof(unsigned long) / 4;
- register unsigned int a1 __asm__("r4");
- register unsigned int a2 __asm__("r5");
- register unsigned int a3 __asm__("r6");
- register unsigned int a4 __asm__("r10");
- register unsigned int b1 __asm__("r8");
- register unsigned int b2 __asm__("r9");
- register unsigned int b3 __asm__("ip");
- register unsigned int b4 __asm__("lr");
-
- do {
- GET_BLOCK_4(p1);
- XOR_BLOCK_4(p2);
- XOR_BLOCK_4(p3);
- PUT_BLOCK_4(p1);
- } while (--lines);
-}
-
-static void
-xor_arm4regs_4(unsigned long bytes, unsigned long * __restrict p1,
- const unsigned long * __restrict p2,
- const unsigned long * __restrict p3,
- const unsigned long * __restrict p4)
-{
- unsigned int lines = bytes / sizeof(unsigned long) / 2;
- register unsigned int a1 __asm__("r8");
- register unsigned int a2 __asm__("r9");
- register unsigned int b1 __asm__("ip");
- register unsigned int b2 __asm__("lr");
-
- do {
- GET_BLOCK_2(p1);
- XOR_BLOCK_2(p2);
- XOR_BLOCK_2(p3);
- XOR_BLOCK_2(p4);
- PUT_BLOCK_2(p1);
- } while (--lines);
-}
-
-static void
-xor_arm4regs_5(unsigned long bytes, unsigned long * __restrict p1,
- const unsigned long * __restrict p2,
- const unsigned long * __restrict p3,
- const unsigned long * __restrict p4,
- const unsigned long * __restrict p5)
-{
- unsigned int lines = bytes / sizeof(unsigned long) / 2;
- register unsigned int a1 __asm__("r8");
- register unsigned int a2 __asm__("r9");
- register unsigned int b1 __asm__("ip");
- register unsigned int b2 __asm__("lr");
-
- do {
- GET_BLOCK_2(p1);
- XOR_BLOCK_2(p2);
- XOR_BLOCK_2(p3);
- XOR_BLOCK_2(p4);
- XOR_BLOCK_2(p5);
- PUT_BLOCK_2(p1);
- } while (--lines);
-}
-
-static struct xor_block_template xor_block_arm4regs = {
- .name = "arm4regs",
- .do_2 = xor_arm4regs_2,
- .do_3 = xor_arm4regs_3,
- .do_4 = xor_arm4regs_4,
- .do_5 = xor_arm4regs_5,
-};
-
-#ifdef CONFIG_KERNEL_MODE_NEON
-
-extern struct xor_block_template const xor_block_neon_inner;
-
-static void
-xor_neon_2(unsigned long bytes, unsigned long * __restrict p1,
- const unsigned long * __restrict p2)
-{
- kernel_neon_begin();
- xor_block_neon_inner.do_2(bytes, p1, p2);
- kernel_neon_end();
-}
-
-static void
-xor_neon_3(unsigned long bytes, unsigned long * __restrict p1,
- const unsigned long * __restrict p2,
- const unsigned long * __restrict p3)
-{
- kernel_neon_begin();
- xor_block_neon_inner.do_3(bytes, p1, p2, p3);
- kernel_neon_end();
-}
-
-static void
-xor_neon_4(unsigned long bytes, unsigned long * __restrict p1,
- const unsigned long * __restrict p2,
- const unsigned long * __restrict p3,
- const unsigned long * __restrict p4)
-{
- kernel_neon_begin();
- xor_block_neon_inner.do_4(bytes, p1, p2, p3, p4);
- kernel_neon_end();
-}
-
-static void
-xor_neon_5(unsigned long bytes, unsigned long * __restrict p1,
- const unsigned long * __restrict p2,
- const unsigned long * __restrict p3,
- const unsigned long * __restrict p4,
- const unsigned long * __restrict p5)
-{
- kernel_neon_begin();
- xor_block_neon_inner.do_5(bytes, p1, p2, p3, p4, p5);
- kernel_neon_end();
-}
-
-static struct xor_block_template xor_block_neon = {
- .name = "neon",
- .do_2 = xor_neon_2,
- .do_3 = xor_neon_3,
- .do_4 = xor_neon_4,
- .do_5 = xor_neon_5
-};
-
-#endif /* CONFIG_KERNEL_MODE_NEON */
+extern struct xor_block_template xor_block_arm4regs;
+extern struct xor_block_template xor_block_neon;

#define arch_xor_init arch_xor_init
static __always_inline void __init arch_xor_init(void)
diff --git a/arch/arm/lib/Makefile b/arch/arm/lib/Makefile
index 0ca5aae1bcc3..9295055cdfc9 100644
--- a/arch/arm/lib/Makefile
+++ b/arch/arm/lib/Makefile
@@ -39,9 +39,4 @@ endif
$(obj)/csumpartialcopy.o: $(obj)/csumpartialcopygeneric.S
$(obj)/csumpartialcopyuser.o: $(obj)/csumpartialcopygeneric.S

-ifeq ($(CONFIG_KERNEL_MODE_NEON),y)
- CFLAGS_xor-neon.o += $(CC_FLAGS_FPU)
- obj-$(CONFIG_XOR_BLOCKS) += xor-neon.o
-endif
-
obj-$(CONFIG_FUNCTION_ERROR_INJECTION) += error-inject.o
diff --git a/lib/raid/xor/Makefile b/lib/raid/xor/Makefile
index 6d03c27c37c7..fb760edae54b 100644
--- a/lib/raid/xor/Makefile
+++ b/lib/raid/xor/Makefile
@@ -9,3 +9,11 @@ xor-y += xor-8regs-prefetch.o
xor-y += xor-32regs-prefetch.o

xor-$(CONFIG_ALPHA) += alpha/xor.o
+xor-$(CONFIG_ARM) += arm/xor.o
+ifeq ($(CONFIG_ARM),y)
+xor-$(CONFIG_KERNEL_MODE_NEON) += arm/xor-neon.o arm/xor-neon-glue.o
+endif
+
+
+CFLAGS_arm/xor-neon.o += $(CC_FLAGS_FPU)
+CFLAGS_REMOVE_arm/xor-neon.o += $(CC_FLAGS_NO_FPU)
diff --git a/lib/raid/xor/arm/xor-neon-glue.c b/lib/raid/xor/arm/xor-neon-glue.c
new file mode 100644
index 000000000000..c7b162b383a2
--- /dev/null
+++ b/lib/raid/xor/arm/xor-neon-glue.c
@@ -0,0 +1,58 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2001 Russell King
+ */
+#include <linux/raid/xor_impl.h>
+#include <asm/xor.h>
+
+extern struct xor_block_template const xor_block_neon_inner;
+
+static void
+xor_neon_2(unsigned long bytes, unsigned long * __restrict p1,
+ const unsigned long * __restrict p2)
+{
+ kernel_neon_begin();
+ xor_block_neon_inner.do_2(bytes, p1, p2);
+ kernel_neon_end();
+}
+
+static void
+xor_neon_3(unsigned long bytes, unsigned long * __restrict p1,
+ const unsigned long * __restrict p2,
+ const unsigned long * __restrict p3)
+{
+ kernel_neon_begin();
+ xor_block_neon_inner.do_3(bytes, p1, p2, p3);
+ kernel_neon_end();
+}
+
+static void
+xor_neon_4(unsigned long bytes, unsigned long * __restrict p1,
+ const unsigned long * __restrict p2,
+ const unsigned long * __restrict p3,
+ const unsigned long * __restrict p4)
+{
+ kernel_neon_begin();
+ xor_block_neon_inner.do_4(bytes, p1, p2, p3, p4);
+ kernel_neon_end();
+}
+
+static void
+xor_neon_5(unsigned long bytes, unsigned long * __restrict p1,
+ const unsigned long * __restrict p2,
+ const unsigned long * __restrict p3,
+ const unsigned long * __restrict p4,
+ const unsigned long * __restrict p5)
+{
+ kernel_neon_begin();
+ xor_block_neon_inner.do_5(bytes, p1, p2, p3, p4, p5);
+ kernel_neon_end();
+}
+
+struct xor_block_template xor_block_neon = {
+ .name = "neon",
+ .do_2 = xor_neon_2,
+ .do_3 = xor_neon_3,
+ .do_4 = xor_neon_4,
+ .do_5 = xor_neon_5
+};
diff --git a/arch/arm/lib/xor-neon.c b/lib/raid/xor/arm/xor-neon.c
similarity index 74%
rename from arch/arm/lib/xor-neon.c
rename to lib/raid/xor/arm/xor-neon.c
index b5be50567991..c9d4378b0f0e 100644
--- a/arch/arm/lib/xor-neon.c
+++ b/lib/raid/xor/arm/xor-neon.c
@@ -1,16 +1,9 @@
// SPDX-License-Identifier: GPL-2.0-only
/*
- * linux/arch/arm/lib/xor-neon.c
- *
* Copyright (C) 2013 Linaro Ltd <ard.biesheuvel@linaro.org>
*/

-#include <linux/raid/xor.h>
#include <linux/raid/xor_impl.h>
-#include <linux/module.h>
-
-MODULE_DESCRIPTION("NEON accelerated XOR implementation");
-MODULE_LICENSE("GPL");

#ifndef __ARM_NEON__
#error You should compile this file with '-march=armv7-a -mfloat-abi=softfp -mfpu=neon'
@@ -27,7 +20,7 @@ MODULE_LICENSE("GPL");
#endif

#define NO_TEMPLATE
-#include "../../../lib/raid/xor/xor-8regs.c"
+#include "../xor-8regs.c"

struct xor_block_template const xor_block_neon_inner = {
.name = "__inner_neon__",
@@ -36,4 +29,3 @@ 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);
diff --git a/lib/raid/xor/arm/xor.c b/lib/raid/xor/arm/xor.c
new file mode 100644
index 000000000000..2263341dbbcd
--- /dev/null
+++ b/lib/raid/xor/arm/xor.c
@@ -0,0 +1,136 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2001 Russell King
+ */
+#include <linux/raid/xor_impl.h>
+#include <asm/xor.h>
+
+#define __XOR(a1, a2) a1 ^= a2
+
+#define GET_BLOCK_2(dst) \
+ __asm__("ldmia %0, {%1, %2}" \
+ : "=r" (dst), "=r" (a1), "=r" (a2) \
+ : "0" (dst))
+
+#define GET_BLOCK_4(dst) \
+ __asm__("ldmia %0, {%1, %2, %3, %4}" \
+ : "=r" (dst), "=r" (a1), "=r" (a2), "=r" (a3), "=r" (a4) \
+ : "0" (dst))
+
+#define XOR_BLOCK_2(src) \
+ __asm__("ldmia %0!, {%1, %2}" \
+ : "=r" (src), "=r" (b1), "=r" (b2) \
+ : "0" (src)); \
+ __XOR(a1, b1); __XOR(a2, b2);
+
+#define XOR_BLOCK_4(src) \
+ __asm__("ldmia %0!, {%1, %2, %3, %4}" \
+ : "=r" (src), "=r" (b1), "=r" (b2), "=r" (b3), "=r" (b4) \
+ : "0" (src)); \
+ __XOR(a1, b1); __XOR(a2, b2); __XOR(a3, b3); __XOR(a4, b4)
+
+#define PUT_BLOCK_2(dst) \
+ __asm__ __volatile__("stmia %0!, {%2, %3}" \
+ : "=r" (dst) \
+ : "0" (dst), "r" (a1), "r" (a2))
+
+#define PUT_BLOCK_4(dst) \
+ __asm__ __volatile__("stmia %0!, {%2, %3, %4, %5}" \
+ : "=r" (dst) \
+ : "0" (dst), "r" (a1), "r" (a2), "r" (a3), "r" (a4))
+
+static void
+xor_arm4regs_2(unsigned long bytes, unsigned long * __restrict p1,
+ const unsigned long * __restrict p2)
+{
+ unsigned int lines = bytes / sizeof(unsigned long) / 4;
+ register unsigned int a1 __asm__("r4");
+ register unsigned int a2 __asm__("r5");
+ register unsigned int a3 __asm__("r6");
+ register unsigned int a4 __asm__("r10");
+ register unsigned int b1 __asm__("r8");
+ register unsigned int b2 __asm__("r9");
+ register unsigned int b3 __asm__("ip");
+ register unsigned int b4 __asm__("lr");
+
+ do {
+ GET_BLOCK_4(p1);
+ XOR_BLOCK_4(p2);
+ PUT_BLOCK_4(p1);
+ } while (--lines);
+}
+
+static void
+xor_arm4regs_3(unsigned long bytes, unsigned long * __restrict p1,
+ const unsigned long * __restrict p2,
+ const unsigned long * __restrict p3)
+{
+ unsigned int lines = bytes / sizeof(unsigned long) / 4;
+ register unsigned int a1 __asm__("r4");
+ register unsigned int a2 __asm__("r5");
+ register unsigned int a3 __asm__("r6");
+ register unsigned int a4 __asm__("r10");
+ register unsigned int b1 __asm__("r8");
+ register unsigned int b2 __asm__("r9");
+ register unsigned int b3 __asm__("ip");
+ register unsigned int b4 __asm__("lr");
+
+ do {
+ GET_BLOCK_4(p1);
+ XOR_BLOCK_4(p2);
+ XOR_BLOCK_4(p3);
+ PUT_BLOCK_4(p1);
+ } while (--lines);
+}
+
+static void
+xor_arm4regs_4(unsigned long bytes, unsigned long * __restrict p1,
+ const unsigned long * __restrict p2,
+ const unsigned long * __restrict p3,
+ const unsigned long * __restrict p4)
+{
+ unsigned int lines = bytes / sizeof(unsigned long) / 2;
+ register unsigned int a1 __asm__("r8");
+ register unsigned int a2 __asm__("r9");
+ register unsigned int b1 __asm__("ip");
+ register unsigned int b2 __asm__("lr");
+
+ do {
+ GET_BLOCK_2(p1);
+ XOR_BLOCK_2(p2);
+ XOR_BLOCK_2(p3);
+ XOR_BLOCK_2(p4);
+ PUT_BLOCK_2(p1);
+ } while (--lines);
+}
+
+static void
+xor_arm4regs_5(unsigned long bytes, unsigned long * __restrict p1,
+ const unsigned long * __restrict p2,
+ const unsigned long * __restrict p3,
+ const unsigned long * __restrict p4,
+ const unsigned long * __restrict p5)
+{
+ unsigned int lines = bytes / sizeof(unsigned long) / 2;
+ register unsigned int a1 __asm__("r8");
+ register unsigned int a2 __asm__("r9");
+ register unsigned int b1 __asm__("ip");
+ register unsigned int b2 __asm__("lr");
+
+ do {
+ GET_BLOCK_2(p1);
+ XOR_BLOCK_2(p2);
+ XOR_BLOCK_2(p3);
+ XOR_BLOCK_2(p4);
+ XOR_BLOCK_2(p5);
+ PUT_BLOCK_2(p1);
+ } while (--lines);
+}
+
+struct xor_block_template xor_block_arm4regs = {
+ .name = "arm4regs",
+ .do_2 = xor_arm4regs_2,
+ .do_3 = xor_arm4regs_3,
+ .do_4 = xor_arm4regs_4,
+ .do_5 = xor_arm4regs_5,
+};
--
2.47.3