csky: Add C based string functions

Try to access RAM with the largest bit width possible, but without
doing unaligned accesses.

A further improvement could be to use multiple read and writes as the
assembly version was trying to do.

Tested on a BeagleV Starlight with a SiFive U74 core, where the
improvement is noticeable.

Signed-off-by: Matteo Croce <mcroce@microsoft.com>
Co-developed-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>

3 files changed, 0 insertions, 355 deletions

diff --git a/arch/csky/abiv1/Makefile b/arch/csky/abiv1/Makefile
index 601ce3b2fb85..a4b2ade0fc67 100644
--- a/arch/csky/abiv1/Makefile
+++ b/arch/csky/abiv1/Makefile
@@ -4,5 +4,3 @@ obj-y					+= bswapdi.o
 obj-y					+= bswapsi.o
 obj-y					+= cacheflush.o
 obj-y					+= mmap.o
-obj-y					+= memcpy.o
-obj-y					+= strksyms.o
diff --git a/arch/csky/abiv1/memcpy.S b/arch/csky/abiv1/memcpy.S
deleted file mode 100644
index 5078eb5169fa..000000000000
--- a/arch/csky/abiv1/memcpy.S
+++ /dev/null
@@ -1,347 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
-
-#include <linux/linkage.h>
-
-.macro	GET_FRONT_BITS rx y
-#ifdef	__cskyLE__
-	lsri	\rx, \y
-#else
-	lsli	\rx, \y
-#endif
-.endm
-
-.macro	GET_AFTER_BITS rx y
-#ifdef	__cskyLE__
-	lsli	\rx, \y
-#else
-	lsri	\rx, \y
-#endif
-.endm
-
-/* void *memcpy(void *dest, const void *src, size_t n); */
-ENTRY(memcpy)
-	mov	r7, r2
-	cmplti	r4, 4
-	bt	.L_copy_by_byte
-	mov	r6, r2
-	andi	r6, 3
-	cmpnei	r6, 0
-	jbt	.L_dest_not_aligned
-	mov	r6, r3
-	andi	r6, 3
-	cmpnei	r6, 0
-	jbt	.L_dest_aligned_but_src_not_aligned
-.L0:
-	cmplti	r4, 16
-	jbt	.L_aligned_and_len_less_16bytes
-	subi	sp, 8
-	stw	r8, (sp, 0)
-.L_aligned_and_len_larger_16bytes:
-	ldw	r1, (r3, 0)
-	ldw	r5, (r3, 4)
-	ldw	r8, (r3, 8)
-	stw	r1, (r7, 0)
-	ldw	r1, (r3, 12)
-	stw	r5, (r7, 4)
-	stw	r8, (r7, 8)
-	stw	r1, (r7, 12)
-	subi	r4, 16
-	addi	r3, 16
-	addi	r7, 16
-	cmplti	r4, 16
-	jbf	.L_aligned_and_len_larger_16bytes
-	ldw	r8, (sp, 0)
-	addi	sp, 8
-	cmpnei	r4, 0
-	jbf	.L_return
-
-.L_aligned_and_len_less_16bytes:
-	cmplti	r4, 4
-	bt	.L_copy_by_byte
-.L1:
-	ldw	r1, (r3, 0)
-	stw	r1, (r7, 0)
-	subi	r4, 4
-	addi	r3, 4
-	addi	r7, 4
-	cmplti	r4, 4
-	jbf	.L1
-	br	.L_copy_by_byte
-
-.L_return:
-	rts
-
-.L_copy_by_byte:                      /* len less than 4 bytes */
-	cmpnei	r4, 0
-	jbf	.L_return
-.L4:
-	ldb	r1, (r3, 0)
-	stb	r1, (r7, 0)
-	addi	r3, 1
-	addi	r7, 1
-	decne	r4
-	jbt	.L4
-	rts
-
-/*
- * If dest is not aligned, just copying some bytes makes the dest align.
- * Afther that, we judge whether the src is aligned.
- */
-.L_dest_not_aligned:
-	mov	r5, r3
-	rsub	r5, r5, r7
-	abs	r5, r5
-	cmplt	r5, r4
-	bt	.L_copy_by_byte
-	mov	r5, r7
-	sub	r5, r3
-	cmphs	r5, r4
-	bf	.L_copy_by_byte
-	mov	r5, r6
-.L5:
-	ldb	r1, (r3, 0)              /* makes the dest align. */
-	stb	r1, (r7, 0)
-	addi	r5, 1
-	subi	r4, 1
-	addi	r3, 1
-	addi	r7, 1
-	cmpnei	r5, 4
-	jbt	.L5
-	cmplti	r4, 4
-	jbt	.L_copy_by_byte
-	mov	r6, r3                   /* judge whether the src is aligned. */
-	andi	r6, 3
-	cmpnei	r6, 0
-	jbf	.L0
-
-/* Judge the number of misaligned, 1, 2, 3? */
-.L_dest_aligned_but_src_not_aligned:
-	mov	r5, r3
-	rsub	r5, r5, r7
-	abs	r5, r5
-	cmplt	r5, r4
-	bt	.L_copy_by_byte
-	bclri	r3, 0
-	bclri	r3, 1
-	ldw	r1, (r3, 0)
-	addi	r3, 4
-	cmpnei	r6, 2
-	bf	.L_dest_aligned_but_src_not_aligned_2bytes
-	cmpnei	r6, 3
-	bf	.L_dest_aligned_but_src_not_aligned_3bytes
-
-.L_dest_aligned_but_src_not_aligned_1byte:
-	mov	r5, r7
-	sub	r5, r3
-	cmphs	r5, r4
-	bf	.L_copy_by_byte
-	cmplti	r4, 16
-	bf	.L11
-.L10:                                     /* If the len is less than 16 bytes */
-	GET_FRONT_BITS r1 8
-	mov	r5, r1
-	ldw	r6, (r3, 0)
-	mov	r1, r6
-	GET_AFTER_BITS r6 24
-	or	r5, r6
-	stw	r5, (r7, 0)
-	subi	r4, 4
-	addi	r3, 4
-	addi	r7, 4
-	cmplti	r4, 4
-	bf	.L10
-	subi	r3, 3
-	br	.L_copy_by_byte
-.L11:
-	subi	sp, 16
-	stw	r8, (sp, 0)
-	stw	r9, (sp, 4)
-	stw	r10, (sp, 8)
-	stw	r11, (sp, 12)
-.L12:
-	ldw	r5, (r3, 0)
-	ldw	r11, (r3, 4)
-	ldw	r8, (r3, 8)
-	ldw	r9, (r3, 12)
-
-	GET_FRONT_BITS r1 8               /* little or big endian? */
-	mov	r10, r5
-	GET_AFTER_BITS r5 24
-	or	r5, r1
-
-	GET_FRONT_BITS r10 8
-	mov	r1, r11
-	GET_AFTER_BITS r11 24
-	or	r11, r10
-
-	GET_FRONT_BITS r1 8
-	mov	r10, r8
-	GET_AFTER_BITS r8 24
-	or	r8, r1
-
-	GET_FRONT_BITS r10 8
-	mov	r1, r9
-	GET_AFTER_BITS r9 24
-	or	r9, r10
-
-	stw	r5, (r7, 0)
-	stw	r11, (r7, 4)
-	stw	r8, (r7, 8)
-	stw	r9, (r7, 12)
-	subi	r4, 16
-	addi	r3, 16
-	addi	r7, 16
-	cmplti	r4, 16
-	jbf	.L12
-	ldw	r8, (sp, 0)
-	ldw	r9, (sp, 4)
-	ldw	r10, (sp, 8)
-	ldw	r11, (sp, 12)
-	addi	sp , 16
-	cmplti	r4, 4
-	bf	.L10
-	subi	r3, 3
-	br	.L_copy_by_byte
-
-.L_dest_aligned_but_src_not_aligned_2bytes:
-	cmplti	r4, 16
-	bf	.L21
-.L20:
-	GET_FRONT_BITS r1 16
-	mov	r5, r1
-	ldw	r6, (r3, 0)
-	mov	r1, r6
-	GET_AFTER_BITS r6 16
-	or	r5, r6
-	stw	r5, (r7, 0)
-	subi	r4, 4
-	addi	r3, 4
-	addi	r7, 4
-	cmplti	r4, 4
-	bf	.L20
-	subi	r3, 2
-	br	.L_copy_by_byte
-	rts
-
-.L21:	/* n > 16 */
-	subi 	sp, 16
-	stw	r8, (sp, 0)
-	stw	r9, (sp, 4)
-	stw	r10, (sp, 8)
-	stw	r11, (sp, 12)
-
-.L22:
-	ldw	r5, (r3, 0)
-	ldw	r11, (r3, 4)
-	ldw	r8, (r3, 8)
-	ldw	r9, (r3, 12)
-
-	GET_FRONT_BITS r1 16
-	mov	r10, r5
-	GET_AFTER_BITS r5 16
-	or	r5, r1
-
-	GET_FRONT_BITS r10 16
-	mov	r1, r11
-	GET_AFTER_BITS r11 16
-	or	r11, r10
-
-	GET_FRONT_BITS r1 16
-	mov	r10, r8
-	GET_AFTER_BITS r8 16
-	or	r8, r1
-
-	GET_FRONT_BITS r10 16
-	mov	r1, r9
-	GET_AFTER_BITS r9 16
-	or	r9, r10
-
-	stw	r5, (r7, 0)
-	stw	r11, (r7, 4)
-	stw	r8, (r7, 8)
-	stw	r9, (r7, 12)
-	subi	r4, 16
-	addi	r3, 16
-	addi	r7, 16
-	cmplti	r4, 16
-	jbf	.L22
-	ldw	r8, (sp, 0)
-	ldw	r9, (sp, 4)
-	ldw	r10, (sp, 8)
-	ldw	r11, (sp, 12)
-	addi	sp, 16
-	cmplti	r4, 4
-	bf	.L20
-	subi	r3, 2
-	br	.L_copy_by_byte
-
-
-.L_dest_aligned_but_src_not_aligned_3bytes:
-	cmplti	r4, 16
-	bf	.L31
-.L30:
-	GET_FRONT_BITS r1 24
-	mov	r5, r1
-	ldw	r6, (r3, 0)
-	mov	r1, r6
-	GET_AFTER_BITS r6 8
-	or	r5, r6
-	stw	r5, (r7, 0)
-	subi	r4, 4
-	addi	r3, 4
-	addi	r7, 4
-	cmplti	r4, 4
-	bf	.L30
-	subi	r3, 1
-	br	.L_copy_by_byte
-.L31:
-	subi	sp, 16
-	stw	r8, (sp, 0)
-	stw	r9, (sp, 4)
-	stw	r10, (sp, 8)
-	stw	r11, (sp, 12)
-.L32:
-	ldw	r5, (r3, 0)
-	ldw	r11, (r3, 4)
-	ldw	r8, (r3, 8)
-	ldw	r9, (r3, 12)
-
-	GET_FRONT_BITS r1 24
-	mov	r10, r5
-	GET_AFTER_BITS r5 8
-	or	r5, r1
-
-	GET_FRONT_BITS r10 24
-	mov	r1, r11
-	GET_AFTER_BITS r11 8
-	or	r11, r10
-
-	GET_FRONT_BITS r1 24
-	mov	r10, r8
-	GET_AFTER_BITS r8 8
-	or	r8, r1
-
-	GET_FRONT_BITS r10 24
-	mov	r1, r9
-	GET_AFTER_BITS r9 8
-	or	r9, r10
-
-	stw	r5, (r7, 0)
-	stw	r11, (r7, 4)
-	stw	r8, (r7, 8)
-	stw	r9, (r7, 12)
-	subi	r4, 16
-	addi	r3, 16
-	addi	r7, 16
-	cmplti	r4, 16
-	jbf	.L32
-	ldw	r8, (sp, 0)
-	ldw	r9, (sp, 4)
-	ldw	r10, (sp, 8)
-	ldw	r11, (sp, 12)
-	addi	sp, 16
-	cmplti	r4, 4
-	bf	.L30
-	subi	r3, 1
-	br	.L_copy_by_byte
diff --git a/arch/csky/abiv1/strksyms.c b/arch/csky/abiv1/strksyms.c
deleted file mode 100644
index c7ccbb27e8d7..000000000000
--- a/arch/csky/abiv1/strksyms.c
+++ /dev/null
@@ -1,6 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
-
-#include <linux/module.h>
-
-EXPORT_SYMBOL(memcpy);