summaryrefslogtreecommitdiffstats
path: root/arch/m68k/lib/checksum.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/m68k/lib/checksum.c')
-rw-r--r--arch/m68k/lib/checksum.c425
1 files changed, 425 insertions, 0 deletions
diff --git a/arch/m68k/lib/checksum.c b/arch/m68k/lib/checksum.c
new file mode 100644
index 000000000..6216f12a7
--- /dev/null
+++ b/arch/m68k/lib/checksum.c
@@ -0,0 +1,425 @@
+/*
+ * 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>
+ * Andreas Schwab, <schwab@issan.informatik.uni-dortmund.de>
+ * Lots of code moved from tcp.c and ip.c; see those files
+ * for more names.
+ *
+ * 03/02/96 Jes Sorensen, Andreas Schwab, Roman Hodek:
+ * Fixed some nasty bugs, causing some horrible crashes.
+ * A: At some points, the sum (%0) was used as
+ * length-counter instead of the length counter
+ * (%1). Thanks to Roman Hodek for pointing this out.
+ * B: GCC seems to mess up if one uses too many
+ * data-registers to hold input values and one tries to
+ * specify d0 and d1 as scratch registers. Letting gcc
+ * choose these registers itself solves the problem.
+ *
+ * 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.
+ *
+ * 1998/8/31 Andreas Schwab:
+ * Zero out rest of buffer on exception in
+ * csum_partial_copy_from_user.
+ */
+
+#include <linux/module.h>
+#include <net/checksum.h>
+
+/*
+ * computes a partial checksum, e.g. for TCP/UDP fragments
+ */
+
+__wsum csum_partial(const void *buff, int len, __wsum sum)
+{
+ unsigned long tmp1, tmp2;
+ /*
+ * Experiments with ethernet and slip connections show that buff
+ * is aligned on either a 2-byte or 4-byte boundary.
+ */
+ __asm__("movel %2,%3\n\t"
+ "btst #1,%3\n\t" /* Check alignment */
+ "jeq 2f\n\t"
+ "subql #2,%1\n\t" /* buff%4==2: treat first word */
+ "jgt 1f\n\t"
+ "addql #2,%1\n\t" /* len was == 2, treat only rest */
+ "jra 4f\n"
+ "1:\t"
+ "addw %2@+,%0\n\t" /* add first word to sum */
+ "clrl %3\n\t"
+ "addxl %3,%0\n" /* add X bit */
+ "2:\t"
+ /* unrolled loop for the main part: do 8 longs at once */
+ "movel %1,%3\n\t" /* save len in tmp1 */
+ "lsrl #5,%1\n\t" /* len/32 */
+ "jeq 2f\n\t" /* not enough... */
+ "subql #1,%1\n"
+ "1:\t"
+ "movel %2@+,%4\n\t"
+ "addxl %4,%0\n\t"
+ "movel %2@+,%4\n\t"
+ "addxl %4,%0\n\t"
+ "movel %2@+,%4\n\t"
+ "addxl %4,%0\n\t"
+ "movel %2@+,%4\n\t"
+ "addxl %4,%0\n\t"
+ "movel %2@+,%4\n\t"
+ "addxl %4,%0\n\t"
+ "movel %2@+,%4\n\t"
+ "addxl %4,%0\n\t"
+ "movel %2@+,%4\n\t"
+ "addxl %4,%0\n\t"
+ "movel %2@+,%4\n\t"
+ "addxl %4,%0\n\t"
+ "dbra %1,1b\n\t"
+ "clrl %4\n\t"
+ "addxl %4,%0\n\t" /* add X bit */
+ "clrw %1\n\t"
+ "subql #1,%1\n\t"
+ "jcc 1b\n"
+ "2:\t"
+ "movel %3,%1\n\t" /* restore len from tmp1 */
+ "andw #0x1c,%3\n\t" /* number of rest longs */
+ "jeq 4f\n\t"
+ "lsrw #2,%3\n\t"
+ "subqw #1,%3\n"
+ "3:\t"
+ /* loop for rest longs */
+ "movel %2@+,%4\n\t"
+ "addxl %4,%0\n\t"
+ "dbra %3,3b\n\t"
+ "clrl %4\n\t"
+ "addxl %4,%0\n" /* add X bit */
+ "4:\t"
+ /* now check for rest bytes that do not fit into longs */
+ "andw #3,%1\n\t"
+ "jeq 7f\n\t"
+ "clrl %4\n\t" /* clear tmp2 for rest bytes */
+ "subqw #2,%1\n\t"
+ "jlt 5f\n\t"
+ "movew %2@+,%4\n\t" /* have rest >= 2: get word */
+ "swap %4\n\t" /* into bits 16..31 */
+ "tstw %1\n\t" /* another byte? */
+ "jeq 6f\n"
+ "5:\t"
+ "moveb %2@,%4\n\t" /* have odd rest: get byte */
+ "lslw #8,%4\n\t" /* into bits 8..15; 16..31 untouched */
+ "6:\t"
+ "addl %4,%0\n\t" /* now add rest long to sum */
+ "clrl %4\n\t"
+ "addxl %4,%0\n" /* add X bit */
+ "7:\t"
+ : "=d" (sum), "=d" (len), "=a" (buff),
+ "=&d" (tmp1), "=&d" (tmp2)
+ : "0" (sum), "1" (len), "2" (buff)
+ );
+ return(sum);
+}
+
+EXPORT_SYMBOL(csum_partial);
+
+
+/*
+ * copy from user space while checksumming, with exception handling.
+ */
+
+__wsum
+csum_partial_copy_from_user(const void __user *src, void *dst,
+ int len, __wsum sum, int *csum_err)
+{
+ /*
+ * GCC doesn't like more than 10 operands for the asm
+ * statements so we have to use tmp2 for the error
+ * code.
+ */
+ unsigned long tmp1, tmp2;
+
+ __asm__("movel %2,%4\n\t"
+ "btst #1,%4\n\t" /* Check alignment */
+ "jeq 2f\n\t"
+ "subql #2,%1\n\t" /* buff%4==2: treat first word */
+ "jgt 1f\n\t"
+ "addql #2,%1\n\t" /* len was == 2, treat only rest */
+ "jra 4f\n"
+ "1:\n"
+ "10:\t"
+ "movesw %2@+,%4\n\t" /* add first word to sum */
+ "addw %4,%0\n\t"
+ "movew %4,%3@+\n\t"
+ "clrl %4\n\t"
+ "addxl %4,%0\n" /* add X bit */
+ "2:\t"
+ /* unrolled loop for the main part: do 8 longs at once */
+ "movel %1,%4\n\t" /* save len in tmp1 */
+ "lsrl #5,%1\n\t" /* len/32 */
+ "jeq 2f\n\t" /* not enough... */
+ "subql #1,%1\n"
+ "1:\n"
+ "11:\t"
+ "movesl %2@+,%5\n\t"
+ "addxl %5,%0\n\t"
+ "movel %5,%3@+\n\t"
+ "12:\t"
+ "movesl %2@+,%5\n\t"
+ "addxl %5,%0\n\t"
+ "movel %5,%3@+\n\t"
+ "13:\t"
+ "movesl %2@+,%5\n\t"
+ "addxl %5,%0\n\t"
+ "movel %5,%3@+\n\t"
+ "14:\t"
+ "movesl %2@+,%5\n\t"
+ "addxl %5,%0\n\t"
+ "movel %5,%3@+\n\t"
+ "15:\t"
+ "movesl %2@+,%5\n\t"
+ "addxl %5,%0\n\t"
+ "movel %5,%3@+\n\t"
+ "16:\t"
+ "movesl %2@+,%5\n\t"
+ "addxl %5,%0\n\t"
+ "movel %5,%3@+\n\t"
+ "17:\t"
+ "movesl %2@+,%5\n\t"
+ "addxl %5,%0\n\t"
+ "movel %5,%3@+\n\t"
+ "18:\t"
+ "movesl %2@+,%5\n\t"
+ "addxl %5,%0\n\t"
+ "movel %5,%3@+\n\t"
+ "dbra %1,1b\n\t"
+ "clrl %5\n\t"
+ "addxl %5,%0\n\t" /* add X bit */
+ "clrw %1\n\t"
+ "subql #1,%1\n\t"
+ "jcc 1b\n"
+ "2:\t"
+ "movel %4,%1\n\t" /* restore len from tmp1 */
+ "andw #0x1c,%4\n\t" /* number of rest longs */
+ "jeq 4f\n\t"
+ "lsrw #2,%4\n\t"
+ "subqw #1,%4\n"
+ "3:\n"
+ /* loop for rest longs */
+ "19:\t"
+ "movesl %2@+,%5\n\t"
+ "addxl %5,%0\n\t"
+ "movel %5,%3@+\n\t"
+ "dbra %4,3b\n\t"
+ "clrl %5\n\t"
+ "addxl %5,%0\n" /* add X bit */
+ "4:\t"
+ /* now check for rest bytes that do not fit into longs */
+ "andw #3,%1\n\t"
+ "jeq 7f\n\t"
+ "clrl %5\n\t" /* clear tmp2 for rest bytes */
+ "subqw #2,%1\n\t"
+ "jlt 5f\n\t"
+ "20:\t"
+ "movesw %2@+,%5\n\t" /* have rest >= 2: get word */
+ "movew %5,%3@+\n\t"
+ "swap %5\n\t" /* into bits 16..31 */
+ "tstw %1\n\t" /* another byte? */
+ "jeq 6f\n"
+ "5:\n"
+ "21:\t"
+ "movesb %2@,%5\n\t" /* have odd rest: get byte */
+ "moveb %5,%3@+\n\t"
+ "lslw #8,%5\n\t" /* into bits 8..15; 16..31 untouched */
+ "6:\t"
+ "addl %5,%0\n\t" /* now add rest long to sum */
+ "clrl %5\n\t"
+ "addxl %5,%0\n\t" /* add X bit */
+ "7:\t"
+ "clrl %5\n" /* no error - clear return value */
+ "8:\n"
+ ".section .fixup,\"ax\"\n"
+ ".even\n"
+ /* If any exception occurs zero out the rest.
+ Similarities with the code above are intentional :-) */
+ "90:\t"
+ "clrw %3@+\n\t"
+ "movel %1,%4\n\t"
+ "lsrl #5,%1\n\t"
+ "jeq 1f\n\t"
+ "subql #1,%1\n"
+ "91:\t"
+ "clrl %3@+\n"
+ "92:\t"
+ "clrl %3@+\n"
+ "93:\t"
+ "clrl %3@+\n"
+ "94:\t"
+ "clrl %3@+\n"
+ "95:\t"
+ "clrl %3@+\n"
+ "96:\t"
+ "clrl %3@+\n"
+ "97:\t"
+ "clrl %3@+\n"
+ "98:\t"
+ "clrl %3@+\n\t"
+ "dbra %1,91b\n\t"
+ "clrw %1\n\t"
+ "subql #1,%1\n\t"
+ "jcc 91b\n"
+ "1:\t"
+ "movel %4,%1\n\t"
+ "andw #0x1c,%4\n\t"
+ "jeq 1f\n\t"
+ "lsrw #2,%4\n\t"
+ "subqw #1,%4\n"
+ "99:\t"
+ "clrl %3@+\n\t"
+ "dbra %4,99b\n\t"
+ "1:\t"
+ "andw #3,%1\n\t"
+ "jeq 9f\n"
+ "100:\t"
+ "clrw %3@+\n\t"
+ "tstw %1\n\t"
+ "jeq 9f\n"
+ "101:\t"
+ "clrb %3@+\n"
+ "9:\t"
+#define STR(X) STR1(X)
+#define STR1(X) #X
+ "moveq #-" STR(EFAULT) ",%5\n\t"
+ "jra 8b\n"
+ ".previous\n"
+ ".section __ex_table,\"a\"\n"
+ ".long 10b,90b\n"
+ ".long 11b,91b\n"
+ ".long 12b,92b\n"
+ ".long 13b,93b\n"
+ ".long 14b,94b\n"
+ ".long 15b,95b\n"
+ ".long 16b,96b\n"
+ ".long 17b,97b\n"
+ ".long 18b,98b\n"
+ ".long 19b,99b\n"
+ ".long 20b,100b\n"
+ ".long 21b,101b\n"
+ ".previous"
+ : "=d" (sum), "=d" (len), "=a" (src), "=a" (dst),
+ "=&d" (tmp1), "=d" (tmp2)
+ : "0" (sum), "1" (len), "2" (src), "3" (dst)
+ );
+
+ *csum_err = tmp2;
+
+ return(sum);
+}
+
+EXPORT_SYMBOL(csum_partial_copy_from_user);
+
+
+/*
+ * copy from kernel space while checksumming, otherwise like csum_partial
+ */
+
+__wsum
+csum_partial_copy_nocheck(const void *src, void *dst, int len, __wsum sum)
+{
+ unsigned long tmp1, tmp2;
+ __asm__("movel %2,%4\n\t"
+ "btst #1,%4\n\t" /* Check alignment */
+ "jeq 2f\n\t"
+ "subql #2,%1\n\t" /* buff%4==2: treat first word */
+ "jgt 1f\n\t"
+ "addql #2,%1\n\t" /* len was == 2, treat only rest */
+ "jra 4f\n"
+ "1:\t"
+ "movew %2@+,%4\n\t" /* add first word to sum */
+ "addw %4,%0\n\t"
+ "movew %4,%3@+\n\t"
+ "clrl %4\n\t"
+ "addxl %4,%0\n" /* add X bit */
+ "2:\t"
+ /* unrolled loop for the main part: do 8 longs at once */
+ "movel %1,%4\n\t" /* save len in tmp1 */
+ "lsrl #5,%1\n\t" /* len/32 */
+ "jeq 2f\n\t" /* not enough... */
+ "subql #1,%1\n"
+ "1:\t"
+ "movel %2@+,%5\n\t"
+ "addxl %5,%0\n\t"
+ "movel %5,%3@+\n\t"
+ "movel %2@+,%5\n\t"
+ "addxl %5,%0\n\t"
+ "movel %5,%3@+\n\t"
+ "movel %2@+,%5\n\t"
+ "addxl %5,%0\n\t"
+ "movel %5,%3@+\n\t"
+ "movel %2@+,%5\n\t"
+ "addxl %5,%0\n\t"
+ "movel %5,%3@+\n\t"
+ "movel %2@+,%5\n\t"
+ "addxl %5,%0\n\t"
+ "movel %5,%3@+\n\t"
+ "movel %2@+,%5\n\t"
+ "addxl %5,%0\n\t"
+ "movel %5,%3@+\n\t"
+ "movel %2@+,%5\n\t"
+ "addxl %5,%0\n\t"
+ "movel %5,%3@+\n\t"
+ "movel %2@+,%5\n\t"
+ "addxl %5,%0\n\t"
+ "movel %5,%3@+\n\t"
+ "dbra %1,1b\n\t"
+ "clrl %5\n\t"
+ "addxl %5,%0\n\t" /* add X bit */
+ "clrw %1\n\t"
+ "subql #1,%1\n\t"
+ "jcc 1b\n"
+ "2:\t"
+ "movel %4,%1\n\t" /* restore len from tmp1 */
+ "andw #0x1c,%4\n\t" /* number of rest longs */
+ "jeq 4f\n\t"
+ "lsrw #2,%4\n\t"
+ "subqw #1,%4\n"
+ "3:\t"
+ /* loop for rest longs */
+ "movel %2@+,%5\n\t"
+ "addxl %5,%0\n\t"
+ "movel %5,%3@+\n\t"
+ "dbra %4,3b\n\t"
+ "clrl %5\n\t"
+ "addxl %5,%0\n" /* add X bit */
+ "4:\t"
+ /* now check for rest bytes that do not fit into longs */
+ "andw #3,%1\n\t"
+ "jeq 7f\n\t"
+ "clrl %5\n\t" /* clear tmp2 for rest bytes */
+ "subqw #2,%1\n\t"
+ "jlt 5f\n\t"
+ "movew %2@+,%5\n\t" /* have rest >= 2: get word */
+ "movew %5,%3@+\n\t"
+ "swap %5\n\t" /* into bits 16..31 */
+ "tstw %1\n\t" /* another byte? */
+ "jeq 6f\n"
+ "5:\t"
+ "moveb %2@,%5\n\t" /* have odd rest: get byte */
+ "moveb %5,%3@+\n\t"
+ "lslw #8,%5\n" /* into bits 8..15; 16..31 untouched */
+ "6:\t"
+ "addl %5,%0\n\t" /* now add rest long to sum */
+ "clrl %5\n\t"
+ "addxl %5,%0\n" /* add X bit */
+ "7:\t"
+ : "=d" (sum), "=d" (len), "=a" (src), "=a" (dst),
+ "=&d" (tmp1), "=&d" (tmp2)
+ : "0" (sum), "1" (len), "2" (src), "3" (dst)
+ );
+ return(sum);
+}
+EXPORT_SYMBOL(csum_partial_copy_nocheck);
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-25 08:25:23 +0000