path: root/arch/metag/lib/usercopy.c

/*
 * User address space access functions.
 * The non-inlined parts of asm-metag/uaccess.h are here.
 *
 * Copyright (C) 2006, Imagination Technologies.
 * Copyright (C) 2000, Axis Communications AB.
 *
 * Written by Hans-Peter Nilsson.
 * Pieces used from memcpy, originally by Kenny Ranerup long time ago.
 * Modified for Meta by Will Newton.
 */

#include <linux/export.h>
#include <linux/uaccess.h>
#include <asm/cache.h>			/* def of L1_CACHE_BYTES */

#define USE_RAPF
#define RAPF_MIN_BUF_SIZE	(3*L1_CACHE_BYTES)


/* The "double write" in this code is because the Meta will not fault
 * immediately unless the memory pipe is forced to by e.g. a data stall or
 * another memory op. The second write should be discarded by the write
 * combiner so should have virtually no cost.
 */

#define __asm_copy_user_cont(to, from, ret, COPY, FIXUP, TENTRY) \
	asm volatile (						 \
		COPY						 \
		"1:\n"						 \
		"	.section .fixup,\"ax\"\n"		 \
		FIXUP						 \
		"	MOVT    D1Ar1,#HI(1b)\n"		 \
		"	JUMP    D1Ar1,#LO(1b)\n"		 \
		"	.previous\n"				 \
		"	.section __ex_table,\"a\"\n"		 \
		TENTRY						 \
		"	.previous\n"				 \
		: "=r" (to), "=r" (from), "=r" (ret)		 \
		: "0" (to), "1" (from), "2" (ret)		 \
		: "D1Ar1", "memory")


#define __asm_copy_to_user_1(to, from, ret)	\
	__asm_copy_user_cont(to, from, ret,	\
		"	GETB D1Ar1,[%1++]\n"	\
		"	SETB [%0],D1Ar1\n"	\
		"2:	SETB [%0++],D1Ar1\n",	\
		"3:	ADD  %2,%2,#1\n",	\
		"	.long 2b,3b\n")

#define __asm_copy_to_user_2x_cont(to, from, ret, COPY, FIXUP, TENTRY) \
	__asm_copy_user_cont(to, from, ret,		\
		"	GETW D1Ar1,[%1++]\n"		\
		"	SETW [%0],D1Ar1\n"		\
		"2:	SETW [%0++],D1Ar1\n" COPY,	\
		"3:	ADD  %2,%2,#2\n" FIXUP,		\
		"	.long 2b,3b\n" TENTRY)

#define __asm_copy_to_user_2(to, from, ret) \
	__asm_copy_to_user_2x_cont(to, from, ret, "", "", "")

#define __asm_copy_to_user_3(to, from, ret) \
	__asm_copy_to_user_2x_cont(to, from, ret,	\
		"	GETB D1Ar1,[%1++]\n"		\
		"	SETB [%0],D1Ar1\n"		\
		"4:	SETB [%0++],D1Ar1\n",		\
		"5:	ADD  %2,%2,#1\n",		\
		"	.long 4b,5b\n")

#define __asm_copy_to_user_4x_cont(to, from, ret, COPY, FIXUP, TENTRY) \
	__asm_copy_user_cont(to, from, ret,		\
		"	GETD D1Ar1,[%1++]\n"		\
		"	SETD [%0],D1Ar1\n"		\
		"2:	SETD [%0++],D1Ar1\n" COPY,	\
		"3:	ADD  %2,%2,#4\n" FIXUP,		\
		"	.long 2b,3b\n" TENTRY)

#define __asm_copy_to_user_4(to, from, ret) \
	__asm_copy_to_user_4x_cont(to, from, ret, "", "", "")

#define __asm_copy_to_user_5(to, from, ret) \
	__asm_copy_to_user_4x_cont(to, from, ret,	\
		"	GETB D1Ar1,[%1++]\n"		\
		"	SETB [%0],D1Ar1\n"		\
		"4:	SETB [%0++],D1Ar1\n",		\
		"5:	ADD  %2,%2,#1\n",		\
		"	.long 4b,5b\n")

#define __asm_copy_to_user_6x_cont(to, from, ret, COPY, FIXUP, TENTRY) \
	__asm_copy_to_user_4x_cont(to, from, ret,	\
		"	GETW D1Ar1,[%1++]\n"		\
		"	SETW [%0],D1Ar1\n"		\
		"4:	SETW [%0++],D1Ar1\n" COPY,	\
		"5:	ADD  %2,%2,#2\n" FIXUP,		\
		"	.long 4b,5b\n" TENTRY)

#define __asm_copy_to_user_6(to, from, ret) \
	__asm_copy_to_user_6x_cont(to, from, ret, "", "", "")

#define __asm_copy_to_user_7(to, from, ret) \
	__asm_copy_to_user_6x_cont(to, from, ret,	\
		"	GETB D1Ar1,[%1++]\n"		\
		"	SETB [%0],D1Ar1\n"		\
		"6:	SETB [%0++],D1Ar1\n",		\
		"7:	ADD  %2,%2,#1\n",		\
		"	.long 6b,7b\n")

#define __asm_copy_to_user_8x_cont(to, from, ret, COPY, FIXUP, TENTRY) \
	__asm_copy_to_user_4x_cont(to, from, ret,	\
		"	GETD D1Ar1,[%1++]\n"		\
		"	SETD [%0],D1Ar1\n"		\
		"4:	SETD [%0++],D1Ar1\n" COPY,	\
		"5:	ADD  %2,%2,#4\n"  FIXUP,	\
		"	.long 4b,5b\n" TENTRY)

#define __asm_copy_to_user_8(to, from, ret) \
	__asm_copy_to_user_8x_cont(to, from, ret, "", "", "")

#define __asm_copy_to_user_9(to, from, ret) \
	__asm_copy_to_user_8x_cont(to, from, ret,	\
		"	GETB D1Ar1,[%1++]\n"		\
		"	SETB [%0],D1Ar1\n"		\
		"6:	SETB [%0++],D1Ar1\n",		\
		"7:	ADD  %2,%2,#1\n",		\
		"	.long 6b,7b\n")

#define __asm_copy_to_user_10x_cont(to, from, ret, COPY, FIXUP, TENTRY) \
	__asm_copy_to_user_8x_cont(to, from, ret,	\
		"	GETW D1Ar1,[%1++]\n"		\
		"	SETW [%0],D1Ar1\n"		\
		"6:	SETW [%0++],D1Ar1\n" COPY,	\
		"7:	ADD  %2,%2,#2\n" FIXUP,		\
		"	.long 6b,7b\n" TENTRY)

#define __asm_copy_to_user_10(to, from, ret) \
	__asm_copy_to_user_10x_cont(to, from, ret, "", "", "")

#define __asm_copy_to_user_11(to, from, ret) \
	__asm_copy_to_user_10x_cont(to, from, ret,	\
		"	GETB D1Ar1,[%1++]\n"		\
		"	SETB [%0],D1Ar1\n"		\
		"8:	SETB [%0++],D1Ar1\n",		\
		"9:	ADD  %2,%2,#1\n",		\
		"	.long 8b,9b\n")

#define __asm_copy_to_user_12x_cont(to, from, ret, COPY, FIXUP, TENTRY) \
	__asm_copy_to_user_8x_cont(to, from, ret,	\
		"	GETD D1Ar1,[%1++]\n"		\
		"	SETD [%0],D1Ar1\n"		\
		"6:	SETD [%0++],D1Ar1\n" COPY,	\
		"7:	ADD  %2,%2,#4\n" FIXUP,		\
		"	.long 6b,7b\n" TENTRY)
#define __asm_copy_to_user_12(to, from, ret) \
	__asm_copy_to_user_12x_cont(to, from, ret, "", "", "")

#define __asm_copy_to_user_13(to, from, ret) \
	__asm_copy_to_user_12x_cont(to, from, ret,	\
		"	GETB D1Ar1,[%1++]\n"		\
		"	SETB [%0],D1Ar1\n"		\
		"8:	SETB [%0++],D1Ar1\n",		\
		"9:	ADD  %2,%2,#1\n",		\
		"	.long 8b,9b\n")

#define __asm_copy_to_user_14x_cont(to, from, ret, COPY, FIXUP, TENTRY) \
	__asm_copy_to_user_12x_cont(to, from, ret,	\
		"	GETW D1Ar1,[%1++]\n"		\
		"	SETW [%0],D1Ar1\n"		\
		"8:	SETW [%0++],D1Ar1\n" COPY,	\
		"9:	ADD  %2,%2,#2\n" FIXUP,		\
		"	.long 8b,9b\n" TENTRY)

#define __asm_copy_to_user_14(to, from, ret) \
	__asm_copy_to_user_14x_cont(to, from, ret, "", "", "")

#define __asm_copy_to_user_15(to, from, ret) \
	__asm_copy_to_user_14x_cont(to, from, ret,	\
		"	GETB D1Ar1,[%1++]\n"		\
		"	SETB [%0],D1Ar1\n"		\
		"10:	SETB [%0++],D1Ar1\n",		\
		"11:	ADD  %2,%2,#1\n",		\
		"	.long 10b,11b\n")

#define __asm_copy_to_user_16x_cont(to, from, ret, COPY, FIXUP, TENTRY) \
	__asm_copy_to_user_12x_cont(to, from, ret,	\
		"	GETD D1Ar1,[%1++]\n"		\
		"	SETD [%0],D1Ar1\n"		\
		"8:	SETD [%0++],D1Ar1\n" COPY,	\
		"9:	ADD  %2,%2,#4\n" FIXUP,		\
		"	.long 8b,9b\n" TENTRY)

#define __asm_copy_to_user_16(to, from, ret) \
		__asm_copy_to_user_16x_cont(to, from, ret, "", "", "")

#define __asm_copy_to_user_8x64(to, from, ret) \
	asm volatile (					\
		"	GETL D0Ar2,D1Ar1,[%1++]\n"	\
		"	SETL [%0],D0Ar2,D1Ar1\n"	\
		"2:	SETL [%0++],D0Ar2,D1Ar1\n"	\
		"1:\n"					\
		"	.section .fixup,\"ax\"\n"	\
		"3:	ADD  %2,%2,#8\n"		\
		"	MOVT    D0Ar2,#HI(1b)\n"	\
		"	JUMP    D0Ar2,#LO(1b)\n"	\
		"	.previous\n"			\
		"	.section __ex_table,\"a\"\n"	\
		"	.long 2b,3b\n"			\
		"	.previous\n"			\
		: "=r" (to), "=r" (from), "=r" (ret)	\
		: "0" (to), "1" (from), "2" (ret)	\
		: "D1Ar1", "D0Ar2", "memory")

/*
 *	optimized copying loop using RAPF when 64 bit aligned
 *
 *	n		will be automatically decremented inside the loop
 *	ret		will be left intact. if error occurs we will rewind