[PATCH 11/25] arm: move the XOR code to lib/raid/

Christoph Hellwig hch at lst.de
Thu Feb 26 07:10:23 PST 2026


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 at 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 at 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




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