Commit e4df2d5e authored by Matteo Croce's avatar Matteo Croce Committed by Guo Ren
Browse files

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: default avatarMatteo Croce <mcroce@microsoft.com>
Co-developed-by: default avatarGuo Ren <guoren@linux.alibaba.com>
Signed-off-by: default avatarGuo Ren <guoren@linux.alibaba.com>
parent cfb24463

arch/csky/Kconfig

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Original line number Diff line number Diff line
@@ -320,6 +320,14 @@ config HOTPLUG_CPU 
	  controlled through /sys/devices/system/cpu/cpu1/hotplug/target.



	  Say N if you want to disable CPU hotplug.



config HAVE_EFFICIENT_UNALIGNED_STRING_OPS

	bool "Enable EFFICIENT_UNALIGNED_STRING_OPS for abiv2"

	depends on CPU_CK807 || CPU_CK810 || CPU_CK860

	help

	  Say Y here to enable EFFICIENT_UNALIGNED_STRING_OPS. Some CPU models could

	  deal with unaligned access by hardware.



endmenu



source "arch/csky/Kconfig.platforms"

arch/csky/abiv1/Makefile

+0 −2
Original line number Diff line number Diff line
@@ -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

arch/csky/abiv1/memcpy.S

deleted100644 → 0
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Original line number Diff line number Diff line 
/* 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

arch/csky/abiv1/strksyms.c

deleted100644 → 0
+0 −6
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.



#include <linux/module.h>



EXPORT_SYMBOL(memcpy);

arch/csky/abiv2/Makefile

+2 −0
Original line number Diff line number Diff line
@@ -2,9 +2,11 @@ 
obj-y				+= cacheflush.o

obj-$(CONFIG_CPU_HAS_FPU)	+= fpu.o

obj-y				+= memcmp.o

ifeq ($(CONFIG_HAVE_EFFICIENT_UNALIGNED_STRING_OPS), y)

obj-y				+= memcpy.o

obj-y				+= memmove.o

obj-y				+= memset.o

endif

obj-y				+= strcmp.o

obj-y				+= strcpy.o

obj-y				+= strlen.o