Initial import

1 files changed, 739 insertions, 0 deletions

diff --git a/arch/mips/lib/memcpy.S b/arch/mips/lib/memcpy.S
new file mode 100644
index 000000000..9245e1705
--- /dev/null
+++ b/arch/mips/lib/memcpy.S
@@ -0,0 +1,739 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Unified implementation of memcpy, memmove and the __copy_user backend.
+ *
+ * Copyright (C) 1998, 99, 2000, 01, 2002 Ralf Baechle (ralf@gnu.org)
+ * Copyright (C) 1999, 2000, 01, 2002 Silicon Graphics, Inc.
+ * Copyright (C) 2002 Broadcom, Inc.
+ *   memcpy/copy_user author: Mark Vandevoorde
+ * Copyright (C) 2007  Maciej W. Rozycki
+ * Copyright (C) 2014 Imagination Technologies Ltd.
+ *
+ * Mnemonic names for arguments to memcpy/__copy_user
+ */
+
+/*
+ * Hack to resolve longstanding prefetch issue
+ *
+ * Prefetching may be fatal on some systems if we're prefetching beyond the
+ * end of memory on some systems.  It's also a seriously bad idea on non
+ * dma-coherent systems.
+ */
+#ifdef CONFIG_DMA_NONCOHERENT
+#undef CONFIG_CPU_HAS_PREFETCH
+#endif
+#ifdef CONFIG_MIPS_MALTA
+#undef CONFIG_CPU_HAS_PREFETCH
+#endif
+
+#include <asm/asm.h>
+#include <asm/asm-offsets.h>
+#include <asm/regdef.h>
+
+#define dst a0
+#define src a1
+#define len a2
+
+/*
+ * Spec
+ *
+ * memcpy copies len bytes from src to dst and sets v0 to dst.
+ * It assumes that
+ *   - src and dst don't overlap
+ *   - src is readable
+ *   - dst is writable
+ * memcpy uses the standard calling convention
+ *
+ * __copy_user copies up to len bytes from src to dst and sets a2 (len) to
+ * the number of uncopied bytes due to an exception caused by a read or write.
+ * __copy_user assumes that src and dst don't overlap, and that the call is
+ * implementing one of the following:
+ *   copy_to_user
+ *     - src is readable  (no exceptions when reading src)
+ *   copy_from_user
+ *     - dst is writable  (no exceptions when writing dst)
+ * __copy_user uses a non-standard calling convention; see
+ * include/asm-mips/uaccess.h
+ *
+ * When an exception happens on a load, the handler must
+ # ensure that all of the destination buffer is overwritten to prevent
+ * leaking information to user mode programs.
+ */
+
+/*
+ * Implementation
+ */
+
+/*
+ * The exception handler for loads requires that:
+ *  1- AT contain the address of the byte just past the end of the source
+ *     of the copy,
+ *  2- src_entry <= src < AT, and
+ *  3- (dst - src) == (dst_entry - src_entry),
+ * The _entry suffix denotes values when __copy_user was called.
+ *
+ * (1) is set up up by uaccess.h and maintained by not writing AT in copy_user
+ * (2) is met by incrementing src by the number of bytes copied
+ * (3) is met by not doing loads between a pair of increments of dst and src
+ *
+ * The exception handlers for stores adjust len (if necessary) and return.
+ * These handlers do not need to overwrite any data.
+ *
+ * For __rmemcpy and memmove an exception is always a kernel bug, therefore
+ * they're not protected.
+ */
+
+/* Instruction type */
+#define LD_INSN 1
+#define ST_INSN 2
+/* Pretech type */
+#define SRC_PREFETCH 1
+#define DST_PREFETCH 2
+#define LEGACY_MODE 1
+#define EVA_MODE    2
+#define USEROP   1
+#define KERNELOP 2
+
+/*
+ * Wrapper to add an entry in the exception table
+ * in case the insn causes a memory exception.
+ * Arguments:
+ * insn    : Load/store instruction
+ * type    : Instruction type
+ * reg     : Register
+ * addr    : Address
+ * handler : Exception handler
+ */
+
+#define EXC(insn, type, reg, addr, handler)			\
+	.if \mode == LEGACY_MODE;				\
+9:		insn reg, addr;					\
+		.section __ex_table,"a";			\
+		PTR	9b, handler;				\
+		.previous;					\
+	/* This is assembled in EVA mode */			\
+	.else;							\
+		/* If loading from user or storing to user */	\
+		.if ((\from == USEROP) && (type == LD_INSN)) || \
+		    ((\to == USEROP) && (type == ST_INSN));	\
+9:			__BUILD_EVA_INSN(insn##e, reg, addr);	\
+			.section __ex_table,"a";		\
+			PTR	9b, handler;			\
+			.previous;				\
+		.else;						\
+			/*					\
+			 *  Still in EVA, but no need for	\
+			 * exception handler or EVA insn	\
+			 */					\
+			insn reg, addr;				\
+		.endif;						\
+	.endif
+
+/*
+ * Only on the 64-bit kernel we can made use of 64-bit registers.
+ */
+#ifdef CONFIG_64BIT
+#define USE_DOUBLE
+#endif
+
+#ifdef USE_DOUBLE
+
+#define LOADK ld /* No exception */
+#define LOAD(reg, addr, handler)	EXC(ld, LD_INSN, reg, addr, handler)
+#define LOADL(reg, addr, handler)	EXC(ldl, LD_INSN, reg, addr, handler)
+#define LOADR(reg, addr, handler)	EXC(ldr, LD_INSN, reg, addr, handler)
+#define STOREL(reg, addr, handler)	EXC(sdl, ST_INSN, reg, addr, handler)
+#define STORER(reg, addr, handler)	EXC(sdr, ST_INSN, reg, addr, handler)
+#define STORE(reg, addr, handler)	EXC(sd, ST_INSN, reg, addr, handler)
+#define ADD    daddu
+#define SUB    dsubu
+#define SRL    dsrl
+#define SRA    dsra
+#define SLL    dsll
+#define SLLV   dsllv
+#define SRLV   dsrlv
+#define NBYTES 8
+#define LOG_NBYTES 3
+
+/*
+ * As we are sharing code base with the mips32 tree (which use the o32 ABI
+ * register definitions). We need to redefine the register definitions from
+ * the n64 ABI register naming to the o32 ABI register naming.
+ */
+#undef t0
+#undef t1
+#undef t2
+#undef t3
+#define t0	$8
+#define t1	$9
+#define t2	$10
+#define t3	$11
+#define t4	$12
+#define t5	$13
+#define t6	$14
+#define t7	$15
+
+#else
+
+#define LOADK lw /* No exception */
+#define LOAD(reg, addr, handler)	EXC(lw, LD_INSN, reg, addr, handler)
+#define LOADL(reg, addr, handler)	EXC(lwl, LD_INSN, reg, addr, handler)
+#define LOADR(reg, addr, handler)	EXC(lwr, LD_INSN, reg, addr, handler)
+#define STOREL(reg, addr, handler)	EXC(swl, ST_INSN, reg, addr, handler)
+#define STORER(reg, addr, handler)	EXC(swr, ST_INSN, reg, addr, handler)
+#define STORE(reg, addr, handler)	EXC(sw, ST_INSN, reg, addr, handler)
+#define ADD    addu
+#define SUB    subu
+#define SRL    srl
+#define SLL    sll
+#define SRA    sra
+#define SLLV   sllv
+#define SRLV   srlv
+#define NBYTES 4
+#define LOG_NBYTES 2
+
+#endif /* USE_DOUBLE */
+
+#define LOADB(reg, addr, handler)	EXC(lb, LD_INSN, reg, addr, handler)
+#define STOREB(reg, addr, handler)	EXC(sb, ST_INSN, reg, addr, handler)
+
+#define _PREF(hint, addr, type)						\
+	.if \mode == LEGACY_MODE;					\
+		PREF(hint, addr);					\
+	.else;								\
+		.if ((\from == USEROP) && (type == SRC_PREFETCH)) ||	\
+		    ((\to == USEROP) && (type == DST_PREFETCH));	\
+			/*						\
+			 * PREFE has only 9 bits for the offset		\
+			 * compared to PREF which has 16, so it may	\
+			 * need to use the $at register but this	\
+			 * register should remain intact because it's	\
+			 * used later on. Therefore use $v1.		\
+			 */						\
+			.set at=v1;					\
+			PREFE(hint, addr);				\
+			.set noat;					\
+		.else;							\
+			PREF(hint, addr);				\
+		.endif;							\
+	.endif
+
+#define PREFS(hint, addr) _PREF(hint, addr, SRC_PREFETCH)
+#define PREFD(hint, addr) _PREF(hint, addr, DST_PREFETCH)
+
+#ifdef CONFIG_CPU_LITTLE_ENDIAN
+#define LDFIRST LOADR
+#define LDREST	LOADL
+#define STFIRST STORER
+#define STREST	STOREL
+#define SHIFT_DISCARD SLLV
+#else
+#define LDFIRST LOADL
+#define LDREST	LOADR
+#define STFIRST STOREL
+#define STREST	STORER
+#define SHIFT_DISCARD SRLV
+#endif
+
+#define FIRST(unit) ((unit)*NBYTES)
+#define REST(unit)  (FIRST(unit)+NBYTES-1)
+#define UNIT(unit)  FIRST(unit)
+
+#define ADDRMASK (NBYTES-1)
+
+	.text
+	.set	noreorder
+#ifndef CONFIG_CPU_DADDI_WORKAROUNDS
+	.set	noat
+#else
+	.set	at=v1
+#endif
+
+	.align	5
+
+	/*
+	 * Macro to build the __copy_user common code
+	 * Arguements:
+	 * mode : LEGACY_MODE or EVA_MODE
+	 * from : Source operand. USEROP or KERNELOP
+	 * to   : Destination operand. USEROP or KERNELOP
+	 */
+	.macro __BUILD_COPY_USER mode, from, to
+
+	/* initialize __memcpy if this the first time we execute this macro */
+	.ifnotdef __memcpy
+	.set __memcpy, 1
+	.hidden __memcpy /* make sure it does not leak */
+	.endif
+
+	/*
+	 * Note: dst & src may be unaligned, len may be 0
+	 * Temps
+	 */
+#define rem t8
+
+	R10KCBARRIER(0(ra))
+	/*
+	 * The "issue break"s below are very approximate.
+	 * Issue delays for dcache fills will perturb the schedule, as will
+	 * load queue full replay traps, etc.
+	 *
+	 * If len < NBYTES use byte operations.
+	 */
+	PREFS(	0, 0(src) )
+	PREFD(	1, 0(dst) )
+	sltu	t2, len, NBYTES
+	and	t1, dst, ADDRMASK
+	PREFS(	0, 1*32(src) )
+	PREFD(	1, 1*32(dst) )
+	bnez	t2, .Lcopy_bytes_checklen\@
+	 and	t0, src, ADDRMASK
+	PREFS(	0, 2*32(src) )
+	PREFD(	1, 2*32(dst) )
+#ifndef CONFIG_CPU_MIPSR6
+	bnez	t1, .Ldst_unaligned\@
+	 nop
+	bnez	t0, .Lsrc_unaligned_dst_aligned\@
+#else
+	or	t0, t0, t1
+	bnez	t0, .Lcopy_unaligned_bytes\@
+#endif
+	/*
+	 * use delay slot for fall-through
+	 * src and dst are aligned; need to compute rem
+	 */
+.Lboth_aligned\@:
+	 SRL	t0, len, LOG_NBYTES+3	 # +3 for 8 units/iter
+	beqz	t0, .Lcleanup_both_aligned\@ # len < 8*NBYTES
+	 and	rem, len, (8*NBYTES-1)	 # rem = len % (8*NBYTES)
+	PREFS(	0, 3*32(src) )
+	PREFD(	1, 3*32(dst) )
+	.align	4
+1:
+	R10KCBARRIER(0(ra))
+	LOAD(t0, UNIT(0)(src), .Ll_exc\@)
+	LOAD(t1, UNIT(1)(src), .Ll_exc_copy\@)
+	LOAD(t2, UNIT(2)(src), .Ll_exc_copy\@)
+	LOAD(t3, UNIT(3)(src), .Ll_exc_copy\@)
+	SUB	len, len, 8*NBYTES
+	LOAD(t4, UNIT(4)(src), .Ll_exc_copy\@)
+	LOAD(t7, UNIT(5)(src), .Ll_exc_copy\@)
+	STORE(t0, UNIT(0)(dst),	.Ls_exc_p8u\@)
+	STORE(t1, UNIT(1)(dst),	.Ls_exc_p7u\@)
+	LOAD(t0, UNIT(6)(src), .Ll_exc_copy\@)
+	LOAD(t1, UNIT(7)(src), .Ll_exc_copy\@)
+	ADD	src, src, 8*NBYTES
+	ADD	dst, dst, 8*NBYTES
+	STORE(t2, UNIT(-6)(dst), .Ls_exc_p6u\@)
+	STORE(t3, UNIT(-5)(dst), .Ls_exc_p5u\@)
+	STORE(t4, UNIT(-4)(dst), .Ls_exc_p4u\@)
+	STORE(t7, UNIT(-3)(dst), .Ls_exc_p3u\@)
+	STORE(t0, UNIT(-2)(dst), .Ls_exc_p2u\@)
+	STORE(t1, UNIT(-1)(dst), .Ls_exc_p1u\@)
+	PREFS(	0, 8*32(src) )
+	PREFD(	1, 8*32(dst) )
+	bne	len, rem, 1b
+	 nop
+
+	/*
+	 * len == rem == the number of bytes left to copy < 8*NBYTES
+	 */
+.Lcleanup_both_aligned\@:
+	beqz	len, .Ldone\@
+	 sltu	t0, len, 4*NBYTES
+	bnez	t0, .Lless_than_4units\@
+	 and	rem, len, (NBYTES-1)	# rem = len % NBYTES
+	/*
+	 * len >= 4*NBYTES
+	 */
+	LOAD( t0, UNIT(0)(src),	.Ll_exc\@)
+	LOAD( t1, UNIT(1)(src),	.Ll_exc_copy\@)
+	LOAD( t2, UNIT(2)(src),	.Ll_exc_copy\@)
+	LOAD( t3, UNIT(3)(src),	.Ll_exc_copy\@)
+	SUB	len, len, 4*NBYTES
+	ADD	src, src, 4*NBYTES
+	R10KCBARRIER(0(ra))
+	STORE(t0, UNIT(0)(dst),	.Ls_exc_p4u\@)
+	STORE(t1, UNIT(1)(dst),	.Ls_exc_p3u\@)
+	STORE(t2, UNIT(2)(dst),	.Ls_exc_p2u\@)
+	STORE(t3, UNIT(3)(dst),	.Ls_exc_p1u\@)
+	.set	reorder				/* DADDI_WAR */
+	ADD	dst, dst, 4*NBYTES
+	beqz	len, .Ldone\@
+	.set	noreorder
+.Lless_than_4units\@:
+	/*
+	 * rem = len % NBYTES
+	 */
+	beq	rem, len, .Lcopy_bytes\@
+	 nop
+1:
+	R10KCBARRIER(0(ra))
+	LOAD(t0, 0(src), .Ll_exc\@)
+	ADD	src, src, NBYTES
+	SUB	len, len, NBYTES
+	STORE(t0, 0(dst), .Ls_exc_p1u\@)
+	.set	reorder				/* DADDI_WAR */
+	ADD	dst, dst, NBYTES
+	bne	rem, len, 1b
+	.set	noreorder
+
+#ifndef CONFIG_CPU_MIPSR6
+	/*
+	 * src and dst are aligned, need to copy rem bytes (rem < NBYTES)
+	 * A loop would do only a byte at a time with possible branch
+	 * mispredicts.	 Can't do an explicit LOAD dst,mask,or,STORE
+	 * because can't assume read-access to dst.  Instead, use
+	 * STREST dst, which doesn't require read access to dst.
+	 *
+	 * This code should perform better than a simple loop on modern,
+	 * wide-issue mips processors because the code has fewer branches and
+	 * more instruction-level parallelism.
+	 */
+#define bits t2
+	beqz	len, .Ldone\@
+	 ADD	t1, dst, len	# t1 is just past last byte of dst
+	li	bits, 8*NBYTES
+	SLL	rem, len, 3	# rem = number of bits to keep
+	LOAD(t0, 0(src), .Ll_exc\@)
+	SUB	bits, bits, rem # bits = number of bits to discard
+	SHIFT_DISCARD t0, t0, bits
+	STREST(t0, -1(t1), .Ls_exc\@)
+	jr	ra
+	 move	len, zero
+.Ldst_unaligned\@:
+	/*
+	 * dst is unaligned
+	 * t0 = src & ADDRMASK
+	 * t1 = dst & ADDRMASK; T1 > 0
+	 * len >= NBYTES
+	 *
+	 * Copy enough bytes to align dst
+	 * Set match = (src and dst have same alignment)
+	 */
+#define match rem
+	LDFIRST(t3, FIRST(0)(src), .Ll_exc\@)
+	ADD	t2, zero, NBYTES
+	LDREST(t3, REST(0)(src), .Ll_exc_copy\@)
+	SUB	t2, t2, t1	# t2 = number of bytes copied
+	xor	match, t0, t1
+	R10KCBARRIER(0(ra))
+	STFIRST(t3, FIRST(0)(dst), .Ls_exc\@)
+	beq	len, t2, .Ldone\@
+	 SUB	len, len, t2
+	ADD	dst, dst, t2
+	beqz	match, .Lboth_aligned\@
+	 ADD	src, src, t2
+
+.Lsrc_unaligned_dst_aligned\@:
+	SRL	t0, len, LOG_NBYTES+2	 # +2 for 4 units/iter
+	PREFS(	0, 3*32(src) )
+	beqz	t0, .Lcleanup_src_unaligned\@
+	 and	rem, len, (4*NBYTES-1)	 # rem = len % 4*NBYTES
+	PREFD(	1, 3*32(dst) )
+1:
+/*
+ * Avoid consecutive LD*'s to the same register since some mips
+ * implementations can't issue them in the same cycle.
+ * It's OK to load FIRST(N+1) before REST(N) because the two addresses
+ * are to the same unit (unless src is aligned, but it's not).
+ */
+	R10KCBARRIER(0(ra))
+	LDFIRST(t0, FIRST(0)(src), .Ll_exc\@)
+	LDFIRST(t1, FIRST(1)(src), .Ll_exc_copy\@)
+	SUB	len, len, 4*NBYTES
+	LDREST(t0, REST(0)(src), .Ll_exc_copy\@)
+	LDREST(t1, REST(1)(src), .Ll_exc_copy\@)
+	LDFIRST(t2, FIRST(2)(src), .Ll_exc_copy\@)
+	LDFIRST(t3, FIRST(3)(src), .Ll_exc_copy\@)
+	LDREST(t2, REST(2)(src), .Ll_exc_copy\@)
+	LDREST(t3, REST(3)(src), .Ll_exc_copy\@)
+	PREFS(	0, 9*32(src) )		# 0 is PREF_LOAD  (not streamed)
+	ADD	src, src, 4*NBYTES
+#ifdef CONFIG_CPU_SB1
+	nop				# improves slotting
+#endif
+	STORE(t0, UNIT(0)(dst),	.Ls_exc_p4u\@)
+	STORE(t1, UNIT(1)(dst),	.Ls_exc_p3u\@)
+	STORE(t2, UNIT(2)(dst),	.Ls_exc_p2u\@)
+	STORE(t3, UNIT(3)(dst),	.Ls_exc_p1u\@)
+	PREFD(	1, 9*32(dst) )		# 1 is PREF_STORE (not streamed)
+	.set	reorder				/* DADDI_WAR */
+	ADD	dst, dst, 4*NBYTES
+	bne	len, rem, 1b
+	.set	noreorder
+
+.Lcleanup_src_unaligned\@:
+	beqz	len, .Ldone\@
+	 and	rem, len, NBYTES-1  # rem = len % NBYTES
+	beq	rem, len, .Lcopy_bytes\@
+	 nop
+1:
+	R10KCBARRIER(0(ra))
+	LDFIRST(t0, FIRST(0)(src), .Ll_exc\@)
+	LDREST(t0, REST(0)(src), .Ll_exc_copy\@)
+	ADD	src, src, NBYTES
+	SUB	len, len, NBYTES
+	STORE(t0, 0(dst), .Ls_exc_p1u\@)
+	.set	reorder				/* DADDI_WAR */
+	ADD	dst, dst, NBYTES
+	bne	len, rem, 1b
+	.set	noreorder
+
+#endif /* !CONFIG_CPU_MIPSR6 */
+.Lcopy_bytes_checklen\@:
+	beqz	len, .Ldone\@
+	 nop
+.Lcopy_bytes\@:
+	/* 0 < len < NBYTES  */
+	R10KCBARRIER(0(ra))
+#define COPY_BYTE(N)			\
+	LOADB(t0, N(src), .Ll_exc\@);	\
+	SUB	len, len, 1;		\
+	beqz	len, .Ldone\@;		\
+	STOREB(t0, N(dst), .Ls_exc_p1\@)
+
+	COPY_BYTE(0)
+	COPY_BYTE(1)
+#ifdef USE_DOUBLE
+	COPY_BYTE(2)
+	COPY_BYTE(3)
+	COPY_BYTE(4)
+	COPY_BYTE(5)
+#endif
+	LOADB(t0, NBYTES-2(src), .Ll_exc\@)
+	SUB	len, len, 1
+	jr	ra
+	STOREB(t0, NBYTES-2(dst), .Ls_exc_p1\@)
+.Ldone\@:
+	jr	ra
+	 nop
+
+#ifdef CONFIG_CPU_MIPSR6
+.Lcopy_unaligned_bytes\@:
+1:
+	COPY_BYTE(0)
+	COPY_BYTE(1)
+	COPY_BYTE(2)
+	COPY_BYTE(3)
+	COPY_BYTE(4)
+	COPY_BYTE(5)
+	COPY_BYTE(6)
+	COPY_BYTE(7)
+	ADD	src, src, 8
+	b	1b
+	 ADD	dst, dst, 8
+#endif /* CONFIG_CPU_MIPSR6 */
+	.if __memcpy == 1
+	END(memcpy)
+	.set __memcpy, 0
+	.hidden __memcpy
+	.endif
+
+.Ll_exc_copy\@:
+	/*
+	 * Copy bytes from src until faulting load address (or until a
+	 * lb faults)
+	 *
+	 * When reached by a faulting LDFIRST/LDREST, THREAD_BUADDR($28)
+	 * may be more than a byte beyond the last address.
+	 * Hence, the lb below may get an exception.
+	 *
+	 * Assumes src < THREAD_BUADDR($28)
+	 */
+	LOADK	t0, TI_TASK($28)
+	 nop
+	LOADK	t0, THREAD_BUADDR(t0)
+1:
+	LOADB(t1, 0(src), .Ll_exc\@)
+	ADD	src, src, 1
+	sb	t1, 0(dst)	# can't fault -- we're copy_from_user
+	.set	reorder				/* DADDI_WAR */
+	ADD	dst, dst, 1
+	bne	src, t0, 1b
+	.set	noreorder
+.Ll_exc\@:
+	LOADK	t0, TI_TASK($28)
+	 nop
+	LOADK	t0, THREAD_BUADDR(t0)	# t0 is just past last good address
+	 nop
+	SUB	len, AT, t0		# len number of uncopied bytes
+	bnez	t6, .Ldone\@	/* Skip the zeroing part if inatomic */
+	/*
+	 * Here's where we rely on src and dst being incremented in tandem,
+	 *   See (3) above.
+	 * dst += (fault addr - src) to put dst at first byte to clear
+	 */
+	ADD	dst, t0			# compute start address in a1
+	SUB	dst, src
+	/*
+	 * Clear len bytes starting at dst.  Can't call __bzero because it
+	 * might modify len.  An inefficient loop for these rare times...
+	 */
+	.set	reorder				/* DADDI_WAR */
+	SUB	src, len, 1
+	beqz	len, .Ldone\@
+	.set	noreorder
+1:	sb	zero, 0(dst)
+	ADD	dst, dst, 1
+#ifndef CONFIG_CPU_DADDI_WORKAROUNDS
+	bnez	src, 1b
+	 SUB	src, src, 1
+#else
+	.set	push
+	.set	noat
+	li	v1, 1
+	bnez	src, 1b
+	 SUB	src, src, v1
+	.set	pop
+#endif
+	jr	ra
+	 nop
+
+
+#define SEXC(n)							\
+	.set	reorder;			/* DADDI_WAR */ \
+.Ls_exc_p ## n ## u\@:						\
+	ADD	len, len, n*NBYTES;				\
+	jr	ra;						\
+	.set	noreorder
+
+SEXC(8)
+SEXC(7)
+SEXC(6)
+SEXC(5)
+SEXC(4)
+SEXC(3)
+SEXC(2)
+SEXC(1)
+
+.Ls_exc_p1\@:
+	.set	reorder				/* DADDI_WAR */
+	ADD	len, len, 1
+	jr	ra
+	.set	noreorder
+.Ls_exc\@:
+	jr	ra
+	 nop
+	.endm
+
+	.align	5
+LEAF(memmove)
+	ADD	t0, a0, a2
+	ADD	t1, a1, a2
+	sltu	t0, a1, t0			# dst + len <= src -> memcpy
+	sltu	t1, a0, t1			# dst >= src + len -> memcpy
+	and	t0, t1
+	beqz	t0, .L__memcpy
+	 move	v0, a0				/* return value */
+	beqz	a2, .Lr_out
+	END(memmove)
+
+	/* fall through to __rmemcpy */
+LEAF(__rmemcpy)					/* a0=dst a1=src a2=len */
+	 sltu	t0, a1, a0
+	beqz	t0, .Lr_end_bytes_up		# src >= dst
+	 nop
+	ADD	a0, a2				# dst = dst + len
+	ADD	a1, a2				# src = src + len
+
+.Lr_end_bytes:
+	R10KCBARRIER(0(ra))
+	lb	t0, -1(a1)
+	SUB	a2, a2, 0x1
+	sb	t0, -1(a0)
+	SUB	a1, a1, 0x1
+	.set	reorder				/* DADDI_WAR */
+	SUB	a0, a0, 0x1
+	bnez	a2, .Lr_end_bytes
+	.set	noreorder
+
+.Lr_out:
+	jr	ra
+	 move	a2, zero
+
+.Lr_end_bytes_up:
+	R10KCBARRIER(0(ra))
+	lb	t0, (a1)
+	SUB	a2, a2, 0x1
+	sb	t0, (a0)
+	ADD	a1, a1, 0x1
+	.set	reorder				/* DADDI_WAR */
+	ADD	a0, a0, 0x1
+	bnez	a2, .Lr_end_bytes_up
+	.set	noreorder
+
+	jr	ra
+	 move	a2, zero
+	END(__rmemcpy)
+
+/*
+ * t6 is used as a flag to note inatomic mode.
+ */
+LEAF(__copy_user_inatomic)
+	b	__copy_user_common
+	li	t6, 1
+	END(__copy_user_inatomic)
+
+/*
+ * A combined memcpy/__copy_user
+ * __copy_user sets len to 0 for success; else to an upper bound of
+ * the number of uncopied bytes.
+ * memcpy sets v0 to dst.
+ */
+	.align	5
+LEAF(memcpy)					/* a0=dst a1=src a2=len */
+	move	v0, dst				/* return value */
+.L__memcpy:
+FEXPORT(__copy_user)
+	li	t6, 0	/* not inatomic */
+__copy_user_common:
+	/* Legacy Mode, user <-> user */
+	__BUILD_COPY_USER LEGACY_MODE USEROP USEROP
+
+#ifdef CONFIG_EVA
+
+/*
+ * For EVA we need distinct symbols for reading and writing to user space.
+ * This is because we need to use specific EVA instructions to perform the
+ * virtual <-> physical translation when a virtual address is actually in user
+ * space
+ */
+
+LEAF(__copy_user_inatomic_eva)
+	b       __copy_from_user_common
+	li	t6, 1
+	END(__copy_user_inatomic_eva)
+
+/*
+ * __copy_from_user (EVA)
+ */
+
+LEAF(__copy_from_user_eva)
+	li	t6, 0	/* not inatomic */
+__copy_from_user_common:
+	__BUILD_COPY_USER EVA_MODE USEROP KERNELOP
+END(__copy_from_user_eva)
+
+
+
+/*
+ * __copy_to_user (EVA)
+ */
+
+LEAF(__copy_to_user_eva)
+__BUILD_COPY_USER EVA_MODE KERNELOP USEROP
+END(__copy_to_user_eva)
+
+/*
+ * __copy_in_user (EVA)
+ */
+
+LEAF(__copy_in_user_eva)
+__BUILD_COPY_USER EVA_MODE USEROP USEROP
+END(__copy_in_user_eva)
+
+#endif