nds32: Library functions

This patch add support for various library functions.

Signed-off-by: Vincent Chen <vincentc@andestech.com>
Signed-off-by: Greentime Hu <greentime@andestech.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>

9 files changed, 355 insertions, 0 deletions

diff --git a/arch/nds32/lib/Makefile b/arch/nds32/lib/Makefile
new file mode 100644
index 0000000000000..0f9840103f032
--- /dev/null
+++ b/arch/nds32/lib/Makefile
@@ -0,0 +1,3 @@
+lib-y		:= copy_page.o memcpy.o memmove.o   \
+		   memset.o memzero.o \
+		   copy_from_user.o copy_to_user.o clear_user.o
diff --git a/arch/nds32/lib/clear_user.S b/arch/nds32/lib/clear_user.S
new file mode 100644
index 0000000000000..805dfcd25bf86
--- /dev/null
+++ b/arch/nds32/lib/clear_user.S
@@ -0,0 +1,42 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2005-2017 Andes Technology Corporation
+
+#include <linux/linkage.h>
+#include <asm/assembler.h>
+#include <asm/errno.h>
+
+/* Prototype: int __arch_clear_user(void *addr, size_t sz)
+ * Purpose  : clear some user memory
+ * Params   : addr - user memory address to clear
+ *          : sz   - number of bytes to clear
+ * Returns  : number of bytes NOT cleared
+ */
+	.text
+	.align	5
+ENTRY(__arch_clear_user)
+	add	$r5, $r0, $r1
+	beqz	$r1, clear_exit
+	xor	$p1, $p1, $p1		! Use $p1=0 to clear mem
+	srli	$p0, $r1, #2		! $p0 = number of word to clear
+	andi	$r1, $r1, #3		! Bytes less than a word to copy
+	beqz	$p0, byte_clear		! Only less than a word to clear
+word_clear:
+USER(	smw.bim,$p1, [$r0], $p1)	! Clear the word
+	addi	$p0, $p0, #-1		! Decrease word count
+	bnez	$p0, word_clear		! Continue looping to clear all words
+	beqz	$r1, clear_exit		! No left bytes to copy
+byte_clear:
+USER(	sbi.bi,	$p1, [$r0], #1)		! Clear the byte
+	addi	$r1, $r1, #-1		! Decrease byte count
+	bnez	$r1, byte_clear		! Continue looping to clear all left bytes
+clear_exit:
+	move	$r0, $r1		! Set return value
+	ret
+
+	.section .fixup,"ax"
+	.align	0
+9001:
+	sub	$r0, $r5, $r0		! Bytes left to copy
+	ret
+	.previous
+ENDPROC(__arch_clear_user)
diff --git a/arch/nds32/lib/copy_from_user.S b/arch/nds32/lib/copy_from_user.S
new file mode 100644
index 0000000000000..ad1857b20067a
--- /dev/null
+++ b/arch/nds32/lib/copy_from_user.S
@@ -0,0 +1,45 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2005-2017 Andes Technology Corporation
+
+#include <linux/linkage.h>
+#include <asm/assembler.h>
+#include <asm/errno.h>
+
+.macro 	lbi1 dst, addr, adj
+USER( lbi.bi, \dst, [\addr], \adj)
+.endm
+
+.macro 	sbi1 src, addr, adj
+sbi.bi	\src, [\addr], \adj
+.endm
+
+.macro	lmw1 start_reg, addr, end_reg
+USER( lmw.bim, \start_reg, [\addr], \end_reg)
+.endm
+
+.macro	smw1 start_reg, addr, end_reg
+smw.bim \start_reg, [\addr], \end_reg
+.endm
+
+
+/* Prototype: int __arch_copy_from_user(void *to, const char *from, size_t n)
+ * Purpose  : copy a block from user memory to kernel memory
+ * Params   : to   - kernel memory
+ *          : from - user memory
+ *          : n    - number of bytes to copy
+ * Returns  : Number of bytes NOT copied.
+ */
+
+.text
+ENTRY(__arch_copy_from_user)
+	add	$r5, $r0, $r2
+#include "copy_template.S"
+	move	$r0, $r2
+	ret
+.section .fixup,"ax"
+.align  2
+9001:
+	sub	$r0, $r5, $r0
+	ret
+.previous
+ENDPROC(__arch_copy_from_user)
diff --git a/arch/nds32/lib/copy_template.S b/arch/nds32/lib/copy_template.S
new file mode 100644
index 0000000000000..3a9a2de468c22
--- /dev/null
+++ b/arch/nds32/lib/copy_template.S
@@ -0,0 +1,69 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2005-2017 Andes Technology Corporation
+
+
+	beq	$r1, $r0, quit_memcpy
+	beqz	$r2, quit_memcpy
+	srli    $r3, $r2, #5	! check if len < cache-line size 32
+	beqz	$r3, word_copy_entry
+	andi	$r4, $r0, #0x3	! check byte-align
+	beqz	$r4, unalign_word_copy_entry
+
+	addi	$r4, $r4,#-4
+	abs	$r4, $r4	! check how many un-align byte to copy
+	sub	$r2, $r2, $r4	! update $R2
+
+unalign_byte_copy:
+	lbi1	$r3, $r1, #1
+	addi	$r4, $r4, #-1
+	sbi1	$r3, $r0, #1
+	bnez	$r4, unalign_byte_copy
+	beqz	$r2, quit_memcpy
+
+unalign_word_copy_entry:
+	andi	$r3, $r0, 0x1f	! check cache-line unaligncount
+	beqz	$r3, cache_copy
+
+	addi	$r3, $r3, #-32
+	abs	$r3, $r3
+	sub	$r2, $r2, $r3	! update $R2
+
+unalign_word_copy:
+	lmw1	$r4, $r1, $r4
+	addi	$r3, $r3, #-4
+	smw1	$r4, $r0, $r4
+	bnez	$r3, unalign_word_copy
+	beqz	$r2, quit_memcpy
+
+	addi	$r3, $r2, #-32	! to check $r2< cache_line , than go to word_copy
+	bltz	$r3, word_copy_entry
+cache_copy:
+	srli	$r3, $r2, #5
+	beqz	$r3, word_copy_entry
+3:
+	lmw1	$r17, $r1, $r24
+	addi	$r3, $r3, #-1
+	smw1	$r17, $r0, $r24
+	bnez	$r3, 3b
+
+word_copy_entry:
+	andi	$r2, $r2, #31
+
+	beqz	$r2, quit_memcpy
+5:
+	srli	$r3, $r2, #2
+	beqz	$r3, byte_copy
+word_copy:
+	lmw1	$r4, $r1, $r4
+	addi	$r3, $r3, #-1
+	smw1	$r4, $r0, $r4
+	bnez	$r3, word_copy
+	andi	$r2, $r2, #3
+	beqz	$r2, quit_memcpy
+byte_copy:
+	lbi1	$r3, $r1, #1
+	addi	$r2, $r2, #-1
+
+	sbi1	$r3, $r0, #1
+	bnez	$r2, byte_copy
+quit_memcpy:
diff --git a/arch/nds32/lib/copy_to_user.S b/arch/nds32/lib/copy_to_user.S
new file mode 100644
index 0000000000000..3230044dcfb87
--- /dev/null
+++ b/arch/nds32/lib/copy_to_user.S
@@ -0,0 +1,45 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2005-2017 Andes Technology Corporation
+
+#include <linux/linkage.h>
+#include <asm/assembler.h>
+#include <asm/errno.h>
+
+.macro 	lbi1 dst, addr, adj
+lbi.bi	\dst, [\addr], \adj
+.endm
+
+.macro 	sbi1 src, addr, adj
+USER( sbi.bi, \src, [\addr], \adj)
+.endm
+
+.macro	lmw1 start_reg, addr, end_reg
+lmw.bim \start_reg, [\addr], \end_reg
+.endm
+
+.macro	smw1 start_reg, addr, end_reg
+USER( smw.bim, \start_reg, [\addr], \end_reg)
+.endm
+
+
+/* Prototype: int __arch_copy_to_user(void *to, const char *from, size_t n)
+ * Purpose  : copy a block to user memory from kernel memory
+ * Params   : to   - user memory
+ *          : from - kernel memory
+ *          : n    - number of bytes to copy
+ * Returns  : Number of bytes NOT copied.
+ */
+
+.text
+ENTRY(__arch_copy_to_user)
+	add	$r5, $r0, $r2
+#include "copy_template.S"
+	move	$r0, $r2
+	ret
+.section .fixup,"ax"
+.align  2
+9001:
+	sub	$r0, $r5, $r0
+	ret
+.previous
+ENDPROC(__arch_copy_to_user)
diff --git a/arch/nds32/lib/memcpy.S b/arch/nds32/lib/memcpy.S
new file mode 100644
index 0000000000000..a2345ea721e46
--- /dev/null
+++ b/arch/nds32/lib/memcpy.S
@@ -0,0 +1,30 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2005-2017 Andes Technology Corporation
+
+#include <linux/linkage.h>
+
+
+.macro 	lbi1 dst, addr, adj
+lbi.bi	\dst, [\addr], \adj
+.endm
+
+.macro 	sbi1 src, addr, adj
+sbi.bi	\src, [\addr], \adj
+.endm
+
+.macro	lmw1 start_reg, addr, end_reg
+lmw.bim \start_reg, [\addr], \end_reg
+.endm
+
+.macro	smw1 start_reg, addr, end_reg
+smw.bim \start_reg, [\addr], \end_reg
+.endm
+
+.text
+ENTRY(memcpy)
+	move	$r5, $r0
+#include "copy_template.S"
+	move	$r0, $r5
+	ret
+
+ENDPROC(memcpy)
diff --git a/arch/nds32/lib/memmove.S b/arch/nds32/lib/memmove.S
new file mode 100644
index 0000000000000..c823aada22714
--- /dev/null
+++ b/arch/nds32/lib/memmove.S
@@ -0,0 +1,70 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2005-2017 Andes Technology Corporation
+
+#include <linux/linkage.h>
+
+/*
+  void *memmove(void *dst, const void *src, int n);
+
+  dst: $r0
+  src: $r1
+  n  : $r2
+  ret: $r0 - pointer to the memory area dst.
+*/
+	.text
+
+ENTRY(memmove)
+	move	$r5, $r0		! Set return value = det
+	beq	$r0, $r1, exit_memcpy	! Exit when det = src
+	beqz	$r2, exit_memcpy	! Exit when n = 0
+	pushm	$t0, $t1		! Save reg
+	srli	$p1, $r2, #2		! $p1 is how many words to copy
+
+	! Avoid data lost when memory overlap
+	! Copy data reversely when src < dst
+	slt	$p0, $r0, $r1		! check if $r0 < $r1
+	beqz	$p0, do_reverse		! branch if dst > src
+
+	! No reverse, dst < src
+	andi	$r2, $r2, #3		! How many bytes are less than a word
+	li	$t0, #1			! Determining copy direction in byte_cpy
+	beqz	$p1, byte_cpy		! When n is less than a word
+
+word_cpy:
+	lmw.bim	$p0, [$r1], $p0		! Read a word from src
+	addi	$p1, $p1, #-1		! How many words left to copy
+	smw.bim	$p0, [$r0], $p0		! Copy the word to det
+	bnez	$p1, word_cpy		! If remained words > 0
+	beqz	$r2, end_memcpy		! No left bytes to copy
+	b	byte_cpy
+
+do_reverse:
+	add	$r0, $r0, $r2		! Start with the end of $r0
+	add	$r1, $r1, $r2		! Start with the end of $r1
+	andi	$r2, $r2, #3		! How many bytes are less than a word
+	li	$t0, #-1		! Determining copy direction in byte_cpy
+	beqz	$p1, reverse_byte_cpy	! When n is less than a word
+
+reverse_word_cpy:
+	lmw.adm	$p0, [$r1], $p0		! Read a word from src
+	addi	$p1, $p1, #-1		! How many words left to copy
+	smw.adm	$p0, [$r0], $p0		! Copy the word to det
+	bnez	$p1, reverse_word_cpy	! If remained words > 0
+	beqz	$r2, end_memcpy		! No left bytes to copy
+
+reverse_byte_cpy:
+	addi	$r0, $r0, #-1
+	addi	$r1, $r1, #-1
+byte_cpy:				! Less than 4 bytes to copy now
+	lb.bi	$p0, [$r1], $t0		! Read a byte from src
+	addi	$r2, $r2, #-1		! How many bytes left to copy
+	sb.bi	$p0, [$r0], $t0		! copy the byte to det
+	bnez	$r2, byte_cpy		! If remained bytes > 0
+
+end_memcpy:
+	popm	$t0, $t1
+exit_memcpy:
+	move	$r0, $r5
+	ret
+
+ENDPROC(memmove)
diff --git a/arch/nds32/lib/memset.S b/arch/nds32/lib/memset.S
new file mode 100644
index 0000000000000..193cb6ce21a94
--- /dev/null
+++ b/arch/nds32/lib/memset.S
@@ -0,0 +1,33 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2005-2017 Andes Technology Corporation
+
+#include <linux/linkage.h>
+
+	.text
+ENTRY(memset)
+	move	$r5, $r0		! Return value
+	beqz	$r2, end_memset		! Exit when len = 0
+	srli	$p1, $r2, 2		! $p1 is how many words to copy
+	andi	$r2, $r2, 3		! How many bytes are less than a word
+	beqz	$p1, byte_set		! When n is less than a word
+
+	! set $r1 from ??????ab to abababab
+	andi	$r1, $r1, #0x00ff	! $r1 = 000000ab
+	slli	$p0, $r1, #8		! $p0 = 0000ab00
+	or	$r1, $r1, $p0		! $r1 = 0000abab
+	slli	$p0, $r1, #16		! $p0 = abab0000
+	or	$r1, $r1, $p0		! $r1 = abababab
+word_set:
+	addi	$p1, $p1, #-1		! How many words left to copy
+	smw.bim	$r1, [$r0], $r1		! Copy the word to det
+	bnez	$p1, word_set		! Still words to set, continue looping
+	beqz	$r2, end_memset		! No left byte to set
+byte_set:				! Less than 4 bytes left to set
+	addi	$r2, $r2, #-1		! Decrease len by 1
+	sbi.bi	$r1, [$r0], #1		! Set data of the next byte to $r1
+	bnez	$r2, byte_set		! Still bytes left to set
+end_memset:
+	move	$r0, $r5
+	ret
+
+ENDPROC(memset)
diff --git a/arch/nds32/lib/memzero.S b/arch/nds32/lib/memzero.S
new file mode 100644
index 0000000000000..f055972c93432
--- /dev/null
+++ b/arch/nds32/lib/memzero.S
@@ -0,0 +1,18 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2005-2017 Andes Technology Corporation
+
+#include <linux/linkage.h>
+
+	.text
+ENTRY(memzero)
+	beqz	$r1, 1f
+	push	$lp
+	move    $r2, $r1
+	move    $r1, #0
+	push	$r0
+	bal     memset
+	pop	$r0
+	pop	$lp
+1:
+        ret
+ENDPROC(memzero)