unicore32 additional architecture files: low-level lib: uaccess

This patch implements low-level uaccess libraries.

Signed-off-by: Guan Xuetao <gxt@mprc.pku.edu.cn>
Acked-by: Arnd Bergmann <arnd@arndb.de>

arch/unicore32/lib/copy_to_user.S

@@ -0,0 +1,96 @@
+/*
+ * linux/arch/unicore32/lib/copy_to_user.S
+ *
+ * Code specific to PKUnity SoC and UniCore ISA
+ *
+ * Copyright (C) 2001-2010 GUAN Xue-tao
+ *
+ * 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/linkage.h>
+#include <asm/assembler.h>
+
+/*
+ * Prototype:
+ *
+ *	size_t __copy_to_user(void *to, const void *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
+ *
+ * Return value:
+ *
+ *	Number of bytes NOT copied.
+ */
+
+	.macro ldr1w ptr reg abort
+	ldw.w \reg, [\ptr]+, #4
+	.endm
+
+	.macro ldr4w ptr reg1 reg2 reg3 reg4 abort
+	ldm.w	(\reg1, \reg2, \reg3, \reg4), [\ptr]+
+	.endm
+
+	.macro ldr8w ptr reg1 reg2 reg3 reg4 reg5 reg6 reg7 reg8 abort
+	ldm.w (\reg1, \reg2, \reg3, \reg4, \reg5, \reg6, \reg7, \reg8), [\ptr]+
+	.endm
+
+	.macro ldr1b ptr reg cond=al abort
+	notcond	\cond, .+8
+	ldb.w \reg, [\ptr]+, #1
+	.endm
+
+	.macro str1w ptr reg abort
+	strusr	\reg, \ptr, 4, abort=\abort
+	.endm
+
+	.macro str8w ptr reg1 reg2 reg3 reg4 reg5 reg6 reg7 reg8 abort
+100:	stm.w (\reg1, \reg2, \reg3, \reg4, \reg5, \reg6, \reg7, \reg8), [\ptr]+
+
+	.pushsection __ex_table, "a"
+	.long 100b, \abort
+	.popsection
+	.endm
+
+	.macro str1b ptr reg cond=al abort
+	strusr	\reg, \ptr, 1, \cond, abort=\abort
+	.endm
+
+	.macro enter
+	mov	r3, #0
+	stm.w	(r0, r2, r3), [sp-]
+	.endm
+
+	.macro exit
+	add	sp, sp, #8
+	ldm.w	(r0), [sp]+
+	mov	pc, lr
+	.endm
+
+	.text
+
+WEAK(__copy_to_user)
+
+#include "copy_template.S"
+
+ENDPROC(__copy_to_user)
+
+	.pushsection .fixup,"ax"
+	.align 0
+	copy_abort_preamble
+	ldm.w	(r1, r2, r3), [sp]+
+	sub	r0, r0, r1
+	rsub	r0, r0, r2
+	copy_abort_end
+	.popsection
+