arm64: crypto: add NEON accelerated XOR implementation

This is a NEON acceleration method that can improve
performance by approximately 20%. I got the following
data from the centos 7.5 on Huawei's HISI1616 chip:

[ 93.837726] xor: measuring software checksum speed
[ 93.874039]   8regs  : 7123.200 MB/sec
[ 93.914038]   32regs : 7180.300 MB/sec
[ 93.954043]   arm64_neon: 9856.000 MB/sec
[ 93.954047] xor: using function: arm64_neon (9856.000 MB/sec)

I believe this code can bring some optimization for
all arm64 platform. thanks for Ard Biesheuvel's suggestions.
Signed-off-by: NJackie Liu <liuyun01@kylinos.cn>
Reviewed-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

arch/arm64/include/asm/Kbuild

@@ -27,4 +27,3 @@ generic-y += trace_clock.h
 generic-y += unaligned.h
 generic-y += user.h
 generic-y += vga.h
-generic-y += xor.h

arch/arm64/include/asm/xor.h

+/*
+ * arch/arm64/include/asm/xor.h
+ *
+ * Authors: Jackie Liu <liuyun01@kylinos.cn>
+ * Copyright (C) 2018,Tianjin KYLIN Information Technology Co., Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/hardirq.h>
+#include <asm-generic/xor.h>
+#include <asm/hwcap.h>
+#include <asm/neon.h>
+
+#ifdef CONFIG_KERNEL_MODE_NEON
+
+extern struct xor_block_template const xor_block_inner_neon;
+
+static void
+xor_neon_2(unsigned long bytes, unsigned long *p1, unsigned long *p2)
+{
+	kernel_neon_begin();
+	xor_block_inner_neon.do_2(bytes, p1, p2);
+	kernel_neon_end();
+}
+
+static void
+xor_neon_3(unsigned long bytes, unsigned long *p1, unsigned long *p2,
+		unsigned long *p3)
+{
+	kernel_neon_begin();
+	xor_block_inner_neon.do_3(bytes, p1, p2, p3);
+	kernel_neon_end();
+}
+
+static void
+xor_neon_4(unsigned long bytes, unsigned long *p1, unsigned long *p2,
+		unsigned long *p3, unsigned long *p4)
+{
+	kernel_neon_begin();
+	xor_block_inner_neon.do_4(bytes, p1, p2, p3, p4);
+	kernel_neon_end();
+}
+
+static void
+xor_neon_5(unsigned long bytes, unsigned long *p1, unsigned long *p2,
+		unsigned long *p3, unsigned long *p4, unsigned long *p5)
+{
+	kernel_neon_begin();
+	xor_block_inner_neon.do_5(bytes, p1, p2, p3, p4, p5);
+	kernel_neon_end();
+}
+
+static struct xor_block_template xor_block_arm64 = {
+	.name   = "arm64_neon",
+	.do_2   = xor_neon_2,
+	.do_3   = xor_neon_3,
+	.do_4   = xor_neon_4,
+	.do_5	= xor_neon_5
+};
+#undef XOR_TRY_TEMPLATES
+#define XOR_TRY_TEMPLATES           \
+	do {        \
+		xor_speed(&xor_block_8regs);    \
+		xor_speed(&xor_block_32regs);    \
+		if (cpu_has_neon()) { \
+			xor_speed(&xor_block_arm64);\
+		} \
+	} while (0)
+
+#endif /* ! CONFIG_KERNEL_MODE_NEON */

arch/arm64/lib/Makefile

@@ -5,6 +5,12 @@ lib-y		:= clear_user.o delay.o copy_from_user.o		\
 		   memcmp.o strcmp.o strncmp.o strlen.o strnlen.o	\
 		   strchr.o strrchr.o tishift.o
 
+ifeq ($(CONFIG_KERNEL_MODE_NEON), y)
+obj-$(CONFIG_XOR_BLOCKS)	+= xor-neon.o
+CFLAGS_REMOVE_xor-neon.o	+= -mgeneral-regs-only
+CFLAGS_xor-neon.o		+= -ffreestanding
+endif
+
 # Tell the compiler to treat all general purpose registers (with the
 # exception of the IP registers, which are already handled by the caller
 # in case of a PLT) as callee-saved, which allows for efficient runtime

arch/arm64/lib/xor-neon.c

+/*
+ * arch/arm64/lib/xor-neon.c
+ *
+ * Authors: Jackie Liu <liuyun01@kylinos.cn>
+ * Copyright (C) 2018,Tianjin KYLIN Information Technology Co., Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/raid/xor.h>
+#include <linux/module.h>
+#include <asm/neon-intrinsics.h>
+
+void xor_arm64_neon_2(unsigned long bytes, unsigned long *p1,
+	unsigned long *p2)
+{
+	uint64_t *dp1 = (uint64_t *)p1;
+	uint64_t *dp2 = (uint64_t *)p2;
+
+	register uint64x2_t v0, v1, v2, v3;
+	long lines = bytes / (sizeof(uint64x2_t) * 4);
+
+	do {
+		/* p1 ^= p2 */
+		v0 = veorq_u64(vld1q_u64(dp1 +  0), vld1q_u64(dp2 +  0));
+		v1 = veorq_u64(vld1q_u64(dp1 +  2), vld1q_u64(dp2 +  2));
+		v2 = veorq_u64(vld1q_u64(dp1 +  4), vld1q_u64(dp2 +  4));
+		v3 = veorq_u64(vld1q_u64(dp1 +  6), vld1q_u64(dp2 +  6));
+
+		/* store */
+		vst1q_u64(dp1 +  0, v0);
+		vst1q_u64(dp1 +  2, v1);
+		vst1q_u64(dp1 +  4, v2);
+		vst1q_u64(dp1 +  6, v3);
+
+		dp1 += 8;
+		dp2 += 8;
+	} while (--lines > 0);
+}
+
+void xor_arm64_neon_3(unsigned long bytes, unsigned long *p1,
+	unsigned long *p2, unsigned long *p3)
+{
+	uint64_t *dp1 = (uint64_t *)p1;
+	uint64_t *dp2 = (uint64_t *)p2;
+	uint64_t *dp3 = (uint64_t *)p3;
+
+	register uint64x2_t v0, v1, v2, v3;
+	long lines = bytes / (sizeof(uint64x2_t) * 4);
+
+	do {
+		/* p1 ^= p2 */
+		v0 = veorq_u64(vld1q_u64(dp1 +  0), vld1q_u64(dp2 +  0));
+		v1 = veorq_u64(vld1q_u64(dp1 +  2), vld1q_u64(dp2 +  2));
+		v2 = veorq_u64(vld1q_u64(dp1 +  4), vld1q_u64(dp2 +  4));
+		v3 = veorq_u64(vld1q_u64(dp1 +  6), vld1q_u64(dp2 +  6));
+
+		/* p1 ^= p3 */
+		v0 = veorq_u64(v0, vld1q_u64(dp3 +  0));
+		v1 = veorq_u64(v1, vld1q_u64(dp3 +  2));
+		v2 = veorq_u64(v2, vld1q_u64(dp3 +  4));
+		v3 = veorq_u64(v3, vld1q_u64(dp3 +  6));
+
+		/* store */
+		vst1q_u64(dp1 +  0, v0);
+		vst1q_u64(dp1 +  2, v1);
+		vst1q_u64(dp1 +  4, v2);
+		vst1q_u64(dp1 +  6, v3);
+
+		dp1 += 8;
+		dp2 += 8;
+		dp3 += 8;
+	} while (--lines > 0);
+}
+
+void xor_arm64_neon_4(unsigned long bytes, unsigned long *p1,
+	unsigned long *p2, unsigned long *p3, unsigned long *p4)
+{
+	uint64_t *dp1 = (uint64_t *)p1;
+	uint64_t *dp2 = (uint64_t *)p2;
+	uint64_t *dp3 = (uint64_t *)p3;
+	uint64_t *dp4 = (uint64_t *)p4;
+
+	register uint64x2_t v0, v1, v2, v3;
+	long lines = bytes / (sizeof(uint64x2_t) * 4);
+
+	do {
+		/* p1 ^= p2 */
+		v0 = veorq_u64(vld1q_u64(dp1 +  0), vld1q_u64(dp2 +  0));
+		v1 = veorq_u64(vld1q_u64(dp1 +  2), vld1q_u64(dp2 +  2));
+		v2 = veorq_u64(vld1q_u64(dp1 +  4), vld1q_u64(dp2 +  4));
+		v3 = veorq_u64(vld1q_u64(dp1 +  6), vld1q_u64(dp2 +  6));
+
+		/* p1 ^= p3 */
+		v0 = veorq_u64(v0, vld1q_u64(dp3 +  0));
+		v1 = veorq_u64(v1, vld1q_u64(dp3 +  2));
+		v2 = veorq_u64(v2, vld1q_u64(dp3 +  4));
+		v3 = veorq_u64(v3, vld1q_u64(dp3 +  6));
+
+		/* p1 ^= p4 */
+		v0 = veorq_u64(v0, vld1q_u64(dp4 +  0));
+		v1 = veorq_u64(v1, vld1q_u64(dp4 +  2));
+		v2 = veorq_u64(v2, vld1q_u64(dp4 +  4));
+		v3 = veorq_u64(v3, vld1q_u64(dp4 +  6));
+
+		/* store */
+		vst1q_u64(dp1 +  0, v0);
+		vst1q_u64(dp1 +  2, v1);
+		vst1q_u64(dp1 +  4, v2);
+		vst1q_u64(dp1 +  6, v3);
+
+		dp1 += 8;
+		dp2 += 8;
+		dp3 += 8;
+		dp4 += 8;
+	} while (--lines > 0);
+}
+
+void xor_arm64_neon_5(unsigned long bytes, unsigned long *p1,
+	unsigned long *p2, unsigned long *p3,
+	unsigned long *p4, unsigned long *p5)
+{
+	uint64_t *dp1 = (uint64_t *)p1;
+	uint64_t *dp2 = (uint64_t *)p2;
+	uint64_t *dp3 = (uint64_t *)p3;
+	uint64_t *dp4 = (uint64_t *)p4;
+	uint64_t *dp5 = (uint64_t *)p5;
+
+	register uint64x2_t v0, v1, v2, v3;
+	long lines = bytes / (sizeof(uint64x2_t) * 4);
+
+	do {
+		/* p1 ^= p2 */
+		v0 = veorq_u64(vld1q_u64(dp1 +  0), vld1q_u64(dp2 +  0));
+		v1 = veorq_u64(vld1q_u64(dp1 +  2), vld1q_u64(dp2 +  2));
+		v2 = veorq_u64(vld1q_u64(dp1 +  4), vld1q_u64(dp2 +  4));
+		v3 = veorq_u64(vld1q_u64(dp1 +  6), vld1q_u64(dp2 +  6));
+
+		/* p1 ^= p3 */
+		v0 = veorq_u64(v0, vld1q_u64(dp3 +  0));
+		v1 = veorq_u64(v1, vld1q_u64(dp3 +  2));
+		v2 = veorq_u64(v2, vld1q_u64(dp3 +  4));
+		v3 = veorq_u64(v3, vld1q_u64(dp3 +  6));
+
+		/* p1 ^= p4 */
+		v0 = veorq_u64(v0, vld1q_u64(dp4 +  0));
+		v1 = veorq_u64(v1, vld1q_u64(dp4 +  2));
+		v2 = veorq_u64(v2, vld1q_u64(dp4 +  4));
+		v3 = veorq_u64(v3, vld1q_u64(dp4 +  6));
+
+		/* p1 ^= p5 */
+		v0 = veorq_u64(v0, vld1q_u64(dp5 +  0));
+		v1 = veorq_u64(v1, vld1q_u64(dp5 +  2));
+		v2 = veorq_u64(v2, vld1q_u64(dp5 +  4));
+		v3 = veorq_u64(v3, vld1q_u64(dp5 +  6));
+
+		/* store */
+		vst1q_u64(dp1 +  0, v0);
+		vst1q_u64(dp1 +  2, v1);
+		vst1q_u64(dp1 +  4, v2);
+		vst1q_u64(dp1 +  6, v3);
+
+		dp1 += 8;
+		dp2 += 8;
+		dp3 += 8;
+		dp4 += 8;
+		dp5 += 8;
+	} while (--lines > 0);
+}
+
+struct xor_block_template const xor_block_inner_neon = {
+	.name	= "__inner_neon__",
+	.do_2	= xor_arm64_neon_2,
+	.do_3	= xor_arm64_neon_3,
+	.do_4	= xor_arm64_neon_4,
+	.do_5	= xor_arm64_neon_5,
+};
+EXPORT_SYMBOL(xor_block_inner_neon);
+
+MODULE_AUTHOR("Jackie Liu <liuyun01@kylinos.cn>");
+MODULE_DESCRIPTION("ARMv8 XOR Extensions");
+MODULE_LICENSE("GPL");