1 files changed, 417 insertions, 0 deletions
diff --git a/arch/sh/lib/checksum.S b/arch/sh/lib/checksum.S
new file mode 100644
index 000000000..356c8ec92
--- /dev/null
+++ b/arch/sh/lib/checksum.S
@@ -0,0 +1,417 @@
+/* $Id: checksum.S,v 1.10 2001/07/06 13:11:32 gniibe Exp $
+ *
+ * INET		An implementation of the TCP/IP protocol suite for the LINUX
+ *		operating system.  INET is implemented using the  BSD Socket
+ *		interface as the means of communication with the user level.
+ *
+ *		IP/TCP/UDP checksumming routines
+ *
+ * Authors:	Jorge Cwik, <jorge@laser.satlink.net>
+ *		Arnt Gulbrandsen, <agulbra@nvg.unit.no>
+ *		Tom May, <ftom@netcom.com>
+ *              Pentium Pro/II routines:
+ *              Alexander Kjeldaas <astor@guardian.no>
+ *              Finn Arne Gangstad <finnag@guardian.no>
+ *		Lots of code moved from tcp.c and ip.c; see those files
+ *		for more names.
+ *
+ * Changes:     Ingo Molnar, converted csum_partial_copy() to 2.1 exception
+ *			     handling.
+ *		Andi Kleen,  add zeroing on error
+ *                   converted to pure assembler
+ *
+ * SuperH version:  Copyright (C) 1999  Niibe Yutaka
+ *
+ *		This program is free software; you can redistribute it and/or
+ *		modify it under the terms of the GNU General Public License
+ *		as published by the Free Software Foundation; either version
+ *		2 of the License, or (at your option) any later version.
+ */
+
+#include <asm/errno.h>
+#include <linux/linkage.h>
+
+/*
+ * computes a partial checksum, e.g. for TCP/UDP fragments
+ */
+
+/*	
+ * asmlinkage __wsum csum_partial(const void *buf, int len, __wsum sum);
+ */
+
+.text
+ENTRY(csum_partial)
+	  /*
+	   * Experiments with Ethernet and SLIP connections show that buff
+	   * is aligned on either a 2-byte or 4-byte boundary.  We get at
+	   * least a twofold speedup on 486 and Pentium if it is 4-byte aligned.
+	   * Fortunately, it is easy to convert 2-byte alignment to 4-byte
+	   * alignment for the unrolled loop.
+	   */
+	mov	r4, r0
+	tst	#3, r0		! Check alignment.
+	bt/s	2f		! Jump if alignment is ok.
+	 mov	r4, r7		! Keep a copy to check for alignment
+	!
+	tst	#1, r0		! Check alignment.
+	bt	21f		! Jump if alignment is boundary of 2bytes.
+
+	! buf is odd
+	tst	r5, r5
+	add	#-1, r5
+	bt	9f
+	mov.b	@r4+, r0
+	extu.b	r0, r0
+	addc	r0, r6		! t=0 from previous tst
+	mov	r6, r0
+	shll8	r6
+	shlr16	r0
+	shlr8	r0
+	or	r0, r6
+	mov	r4, r0
+	tst	#2, r0
+	bt	2f
+21:
+	! buf is 2 byte aligned (len could be 0)
+	add	#-2, r5		! Alignment uses up two bytes.
+	cmp/pz	r5		!
+	bt/s	1f		! Jump if we had at least two bytes.
+	 clrt
+	bra	6f
+	 add	#2, r5		! r5 was < 2.  Deal with it.
+1:
+	mov.w	@r4+, r0
+	extu.w	r0, r0
+	addc	r0, r6
+	bf	2f
+	add	#1, r6
+2:
+	! buf is 4 byte aligned (len could be 0)
+	mov	r5, r1
+	mov	#-5, r0
+	shld	r0, r1
+	tst	r1, r1
+	bt/s	4f		! if it's =0, go to 4f
+	 clrt
+	.align	2
+3:
+	mov.l	@r4+, r0
+	mov.l	@r4+, r2
+	mov.l	@r4+, r3
+	addc	r0, r6
+	mov.l	@r4+, r0
+	addc	r2, r6
+	mov.l	@r4+, r2
+	addc	r3, r6
+	mov.l	@r4+, r3
+	addc	r0, r6
+	mov.l	@r4+, r0
+	addc	r2, r6
+	mov.l	@r4+, r2
+	addc	r3, r6
+	addc	r0, r6
+	addc	r2, r6
+	movt	r0
+	dt	r1
+	bf/s	3b
+	 cmp/eq	#1, r0
+	! here, we know r1==0
+	addc	r1, r6			! add carry to r6
+4:
+	mov	r5, r0
+	and	#0x1c, r0
+	tst	r0, r0
+	bt	6f
+	! 4 bytes or more remaining
+	mov	r0, r1
+	shlr2	r1
+	mov	#0, r2
+5:
+	addc	r2, r6
+	mov.l	@r4+, r2
+	movt	r0
+	dt	r1
+	bf/s	5b
+	 cmp/eq	#1, r0
+	addc	r2, r6
+	addc	r1, r6		! r1==0 here, so it means add carry-bit
+6:
+	! 3 bytes or less remaining
+	mov	#3, r0
+	and	r0, r5
+	tst	r5, r5
+	bt	9f		! if it's =0 go to 9f
+	mov	#2, r1
+	cmp/hs  r1, r5
+	bf	7f
+	mov.w	@r4+, r0
+	extu.w	r0, r0
+	cmp/eq	r1, r5
+	bt/s	8f
+	 clrt
+	shll16	r0
+	addc	r0, r6
+7:
+	mov.b	@r4+, r0
+	extu.b	r0, r0
+#ifndef	__LITTLE_ENDIAN__
+	shll8	r0
+#endif
+8:
+	addc	r0, r6
+	mov	#0, r0
+	addc	r0, r6
+9:
+	! Check if the buffer was misaligned, if so realign sum
+	mov	r7, r0
+	tst	#1, r0
+	bt	10f
+	mov	r6, r0
+	shll8	r6
+	shlr16	r0
+	shlr8	r0
+	or	r0, r6
+10:
+	rts
+	 mov	r6, r0
+
+/*
+unsigned int csum_partial_copy_generic (const char *src, char *dst, int len, 
+					int sum, int *src_err_ptr, int *dst_err_ptr)
+ */ 
+
+/*
+ * Copy from ds while checksumming, otherwise like csum_partial
+ *
+ * The macros SRC and DST specify the type of access for the instruction.
+ * thus we can call a custom exception handler for all access types.
+ *
+ * FIXME: could someone double-check whether I haven't mixed up some SRC and
+ *	  DST definitions? It's damn hard to trigger all cases.  I hope I got
+ *	  them all but there's no guarantee.
+ */
+
+#define SRC(...)			\
+	9999: __VA_ARGS__ ;		\
+	.section __ex_table, "a";	\
+	.long 9999b, 6001f	;	\
+	.previous
+
+#define DST(...)			\
+	9999: __VA_ARGS__ ;		\
+	.section __ex_table, "a";	\
+	.long 9999b, 6002f	;	\
+	.previous
+
+!
+! r4:	const char *SRC
+! r5:	char *DST
+! r6:	int LEN
+! r7:	int SUM
+!
+! on stack:
+! int *SRC_ERR_PTR
+! int *DST_ERR_PTR
+!
+ENTRY(csum_partial_copy_generic)
+	mov.l	r5,@-r15
+	mov.l	r6,@-r15
+
+	mov	#3,r0		! Check src and dest are equally aligned
+	mov	r4,r1
+	and	r0,r1
+	and	r5,r0
+	cmp/eq	r1,r0
+	bf	3f		! Different alignments, use slow version
+	tst	#1,r0		! Check dest word aligned
+	bf	3f		! If not, do it the slow way
+
+	mov	#2,r0
+	tst	r0,r5		! Check dest alignment. 
+	bt	2f		! Jump if alignment is ok.
+	add	#-2,r6		! Alignment uses up two bytes.
+	cmp/pz	r6		! Jump if we had at least two bytes.
+	bt/s	1f
+	 clrt
+	add	#2,r6		! r6 was < 2.	Deal with it.
+	bra	4f
+	 mov	r6,r2
+
+3:	! Handle different src and dest alignments.
+	! This is not common, so simple byte by byte copy will do.
+	mov	r6,r2
+	shlr	r6
+	tst	r6,r6
+	bt	4f
+	clrt
+	.align	2
+5:
+SRC(	mov.b	@r4+,r1 	)
+SRC(	mov.b	@r4+,r0		)
+	extu.b	r1,r1
+DST(	mov.b	r1,@r5		)
+DST(	mov.b	r0,@(1,r5)	)
+	extu.b	r0,r0
+	add	#2,r5
+
+#ifdef	__LITTLE_ENDIAN__
+	shll8	r0
+#else
+	shll8	r1
+#endif
+	or	r1,r0
+
+	addc	r0,r7
+	movt	r0
+	dt	r6
+	bf/s	5b
+	 cmp/eq	#1,r0
+	mov	#0,r0
+	addc	r0, r7
+
+	mov	r2, r0
+	tst	#1, r0
+	bt	7f
+	bra	5f
+	 clrt
+
+	! src and dest equally aligned, but to a two byte boundary.
+	! Handle first two bytes as a special case
+	.align	2
+1:	
+SRC(	mov.w	@r4+,r0		)
+DST(	mov.w	r0,@r5		)
+	add	#2,r5
+	extu.w	r0,r0
+	addc	r0,r7
+	mov	#0,r0
+	addc	r0,r7
+2:
+	mov	r6,r2
+	mov	#-5,r0
+	shld	r0,r6
+	tst	r6,r6
+	bt/s	2f
+	 clrt
+	.align	2
+1:	
+SRC(	mov.l	@r4+,r0		)
+SRC(	mov.l	@r4+,r1		)
+	addc	r0,r7
+DST(	mov.l	r0,@r5		)
+DST(	mov.l	r1,@(4,r5)	)
+	addc	r1,r7
+
+SRC(	mov.l	@r4+,r0		)
+SRC(	mov.l	@r4+,r1		)
+	addc	r0,r7
+DST(	mov.l	r0,@(8,r5)	)
+DST(	mov.l	r1,@(12,r5)	)
+	addc	r1,r7
+
+SRC(	mov.l	@r4+,r0 	)
+SRC(	mov.l	@r4+,r1		)
+	addc	r0,r7
+DST(	mov.l	r0,@(16,r5)	)
+DST(	mov.l	r1,@(20,r5)	)
+	addc	r1,r7
+
+SRC(	mov.l	@r4+,r0		)
+SRC(	mov.l	@r4+,r1		)
+	addc	r0,r7
+DST(	mov.l	r0,@(24,r5)	)
+DST(	mov.l	r1,@(28,r5)	)
+	addc	r1,r7
+	add	#32,r5
+	movt	r0
+	dt	r6
+	bf/s	1b
+	 cmp/eq	#1,r0
+	mov	#0,r0
+	addc	r0,r7
+
+2:	mov	r2,r6
+	mov	#0x1c,r0
+	and	r0,r6
+	cmp/pl	r6
+	bf/s	4f
+	 clrt
+	shlr2	r6
+3:	
+SRC(	mov.l	@r4+,r0	)
+	addc	r0,r7
+DST(	mov.l	r0,@r5	)
+	add	#4,r5
+	movt	r0
+	dt	r6
+	bf/s	3b
+	 cmp/eq	#1,r0
+	mov	#0,r0
+	addc	r0,r7
+4:	mov	r2,r6
+	mov	#3,r0
+	and	r0,r6
+	cmp/pl	r6
+	bf	7f
+	mov	#2,r1
+	cmp/hs	r1,r6
+	bf	5f
+SRC(	mov.w	@r4+,r0	)
+DST(	mov.w	r0,@r5	)
+	extu.w	r0,r0
+	add	#2,r5
+	cmp/eq	r1,r6
+	bt/s	6f
+	 clrt
+	shll16	r0
+	addc	r0,r7
+5:	
+SRC(	mov.b	@r4+,r0	)
+DST(	mov.b	r0,@r5	)
+	extu.b	r0,r0
+#ifndef	__LITTLE_ENDIAN__
+	shll8	r0
+#endif
+6:	addc	r0,r7
+	mov	#0,r0
+	addc	r0,r7
+7:
+5000:
+
+# Exception handler:
+.section .fixup, "ax"							
+
+6001:
+	mov.l	@(8,r15),r0			! src_err_ptr
+	mov	#-EFAULT,r1
+	mov.l	r1,@r0
+
+	! zero the complete destination - computing the rest
+	! is too much work 
+	mov.l	@(4,r15),r5		! dst
+	mov.l	@r15,r6			! len
+	mov	#0,r7
+1:	mov.b	r7,@r5
+	dt	r6
+	bf/s	1b
+	 add	#1,r5
+	mov.l	8000f,r0
+	jmp	@r0
+	 nop
+	.align	2
+8000:	.long	5000b
+
+6002:
+	mov.l	@(12,r15),r0			! dst_err_ptr
+	mov	#-EFAULT,r1
+	mov.l	r1,@r0
+	mov.l	8001f,r0
+	jmp	@r0
+	 nop
+	.align	2
+8001:	.long	5000b
+
+.previous
+	add	#8,r15
+	rts
+	 mov	r7,r0