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.
That is patch version 5. Thanks for Ard Biesheuvel's
suggestions.
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
Signed-off-by: Jackie Liu <liuyun01@xxxxxxxxxx>
---
arch/arm64/include/asm/Kbuild | 1 -
arch/arm64/include/asm/xor.h | 73 +++++++++++++++++
arch/arm64/lib/Makefile | 6 ++
arch/arm64/lib/xor-neon.c | 184 ++++++++++++++++++++++++++++++++++++++++++
4 files changed, 263 insertions(+), 1 deletion(-)
create mode 100644 arch/arm64/include/asm/xor.h
create mode 100644 arch/arm64/lib/xor-neon.c
diff --git a/arch/arm64/include/asm/Kbuild b/arch/arm64/include/asm/Kbuild
index 6cd5d77..1877f29 100644
--- a/arch/arm64/include/asm/Kbuild
+++ b/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
diff --git a/arch/arm64/include/asm/xor.h b/arch/arm64/include/asm/xor.h
new file mode 100644
index 0000000..856386a
--- /dev/null
+++ b/arch/arm64/include/asm/xor.h
@@ -0,0 +1,73 @@
+/*
+ * arch/arm64/include/asm/xor.h
+ *
+ * Authors: Jackie Liu <liuyun01@xxxxxxxxxx>
+ * 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 */
diff --git a/arch/arm64/lib/Makefile b/arch/arm64/lib/Makefile
index 69ff988..5540a16 100644
--- a/arch/arm64/lib/Makefile
+++ b/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
diff --git a/arch/arm64/lib/xor-neon.c b/arch/arm64/lib/xor-neon.c
new file mode 100644
index 0000000..131c60c2
--- /dev/null
+++ b/arch/arm64/lib/xor-neon.c
@@ -0,0 +1,184 @@
+/*
+ * arch/arm64/lib/xor-neon.c
+ *
+ * Authors: Jackie Liu <liuyun01@xxxxxxxxxx>
+ * 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@xxxxxxxxxx>");
+MODULE_DESCRIPTION("ARMv8 XOR Extensions");
+MODULE_LICENSE("GPL");
--
2.7.4
