| /* |
| * 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 |
| */ |
| |
| unsigned int |
| csum_partial (const unsigned char *buff, int len, unsigned int 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. |
| */ |
| |
| unsigned int |
| csum_partial_copy_from_user(const unsigned char __user *src, unsigned char *dst, |
| int len, int 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); |
| } |
| |
| /* |
| * copy from kernel space while checksumming, otherwise like csum_partial |
| */ |
| |
| unsigned int |
| csum_partial_copy_nocheck(const unsigned char *src, unsigned char *dst, int len, int 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); |
| } |
