1 files changed, 147 insertions, 0 deletions
diff --git a/arch/loongarch/lib/memmove.S b/arch/loongarch/lib/memmove.S
new file mode 100644
index 000000000000..82dae062fec8
--- /dev/null
+++ b/arch/loongarch/lib/memmove.S
@@ -0,0 +1,147 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+
+#include <linux/export.h>
+#include <asm/alternative-asm.h>
+#include <asm/asm.h>
+#include <asm/asmmacro.h>
+#include <asm/cpu.h>
+#include <asm/regdef.h>
+
+.section .noinstr.text, "ax"
+
+SYM_FUNC_START(memmove)
+	blt	a0, a1, __memcpy	/* dst < src, memcpy */
+	blt	a1, a0, __rmemcpy	/* src < dst, rmemcpy */
+	jr	ra			/* dst == src, return */
+SYM_FUNC_END(memmove)
+SYM_FUNC_ALIAS(__memmove, memmove)
+
+EXPORT_SYMBOL(memmove)
+EXPORT_SYMBOL(__memmove)
+
+_ASM_NOKPROBE(memmove)
+_ASM_NOKPROBE(__memmove)
+
+SYM_FUNC_START(__rmemcpy)
+	/*
+	 * Some CPUs support hardware unaligned access
+	 */
+	ALTERNATIVE	"b __rmemcpy_generic", \
+			"b __rmemcpy_fast", CPU_FEATURE_UAL
+SYM_FUNC_END(__rmemcpy)
+_ASM_NOKPROBE(__rmemcpy)
+
+/*
+ * void *__rmemcpy_generic(void *dst, const void *src, size_t n)
+ *
+ * a0: dst
+ * a1: src
+ * a2: n
+ */
+SYM_FUNC_START(__rmemcpy_generic)
+	move	a3, a0
+	beqz	a2, 2f
+
+	add.d	a0, a0, a2
+	add.d	a1, a1, a2
+
+1:	ld.b	t0, a1, -1
+	st.b	t0, a0, -1
+	addi.d	a0, a0, -1
+	addi.d	a1, a1, -1
+	addi.d	a2, a2, -1
+	bgt	a2, zero, 1b
+
+2:	move	a0, a3
+	jr	ra
+SYM_FUNC_END(__rmemcpy_generic)
+_ASM_NOKPROBE(__rmemcpy_generic)
+
+/*
+ * void *__rmemcpy_fast(void *dst, const void *src, size_t n)
+ *
+ * a0: dst
+ * a1: src
+ * a2: n
+ */
+SYM_FUNC_START(__rmemcpy_fast)
+	sltui	t0, a2, 9
+	bnez	t0, __memcpy_small
+
+	add.d	a3, a1, a2
+	add.d	a2, a0, a2
+	ld.d	a6, a1, 0
+	ld.d	a7, a3, -8
+
+	/* align up destination address */
+	andi	t1, a2, 7
+	sub.d	a3, a3, t1
+	sub.d	a5, a2, t1
+
+	addi.d	a4, a1, 64
+	bgeu	a4, a3, .Llt64
+
+	/* copy 64 bytes at a time */
+.Lloop64:
+	ld.d	t0, a3, -8
+	ld.d	t1, a3, -16
+	ld.d	t2, a3, -24
+	ld.d	t3, a3, -32
+	ld.d	t4, a3, -40
+	ld.d	t5, a3, -48
+	ld.d	t6, a3, -56
+	ld.d	t7, a3, -64
+	addi.d	a3, a3, -64
+	st.d	t0, a5, -8
+	st.d	t1, a5, -16
+	st.d	t2, a5, -24
+	st.d	t3, a5, -32
+	st.d	t4, a5, -40
+	st.d	t5, a5, -48
+	st.d	t6, a5, -56
+	st.d	t7, a5, -64
+	addi.d	a5, a5, -64
+	bltu	a4, a3, .Lloop64
+
+	/* copy the remaining bytes */
+.Llt64:
+	addi.d	a4, a1, 32
+	bgeu	a4, a3, .Llt32
+	ld.d	t0, a3, -8
+	ld.d	t1, a3, -16
+	ld.d	t2, a3, -24
+	ld.d	t3, a3, -32
+	addi.d	a3, a3, -32
+	st.d	t0, a5, -8
+	st.d	t1, a5, -16
+	st.d	t2, a5, -24
+	st.d	t3, a5, -32
+	addi.d	a5, a5, -32
+
+.Llt32:
+	addi.d	a4, a1, 16
+	bgeu	a4, a3, .Llt16
+	ld.d	t0, a3, -8
+	ld.d	t1, a3, -16
+	addi.d	a3, a3, -16
+	st.d	t0, a5, -8
+	st.d	t1, a5, -16
+	addi.d	a5, a5, -16
+
+.Llt16:
+	addi.d	a4, a1, 8
+	bgeu	a4, a3, .Llt8
+	ld.d	t0, a3, -8
+	st.d	t0, a5, -8
+
+.Llt8:
+	st.d	a6, a0, 0
+	st.d	a7, a2, -8
+
+	/* return */
+	jr	ra
+SYM_FUNC_END(__rmemcpy_fast)
+_ASM_NOKPROBE(__rmemcpy_fast)