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Diffstat (limited to 'arch/x86/um/checksum_32.S')
| -rw-r--r-- | arch/x86/um/checksum_32.S | 458 |
1 files changed, 458 insertions, 0 deletions
diff --git a/arch/x86/um/checksum_32.S b/arch/x86/um/checksum_32.S new file mode 100644 index 00000000000..f058d2f82e1 --- /dev/null +++ b/arch/x86/um/checksum_32.S @@ -0,0 +1,458 @@ +/* + * 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 + * + * 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> + +/* + * computes a partial checksum, e.g. for TCP/UDP fragments + */ + +/* +unsigned int csum_partial(const unsigned char * buff, int len, unsigned int sum) + */ + +.text +.align 4 +.globl csum_partial + +#ifndef CONFIG_X86_USE_PPRO_CHECKSUM + + /* + * 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. + */ +csum_partial: + pushl %esi + pushl %ebx + movl 20(%esp),%eax # Function arg: unsigned int sum + movl 16(%esp),%ecx # Function arg: int len + movl 12(%esp),%esi # Function arg: unsigned char *buff + testl $2, %esi # Check alignment. + jz 2f # Jump if alignment is ok. + subl $2, %ecx # Alignment uses up two bytes. + jae 1f # Jump if we had at least two bytes. + addl $2, %ecx # ecx was < 2. Deal with it. + jmp 4f +1: movw (%esi), %bx + addl $2, %esi + addw %bx, %ax + adcl $0, %eax +2: + movl %ecx, %edx + shrl $5, %ecx + jz 2f + testl %esi, %esi +1: movl (%esi), %ebx + adcl %ebx, %eax + movl 4(%esi), %ebx + adcl %ebx, %eax + movl 8(%esi), %ebx + adcl %ebx, %eax + movl 12(%esi), %ebx + adcl %ebx, %eax + movl 16(%esi), %ebx + adcl %ebx, %eax + movl 20(%esi), %ebx + adcl %ebx, %eax + movl 24(%esi), %ebx + adcl %ebx, %eax + movl 28(%esi), %ebx + adcl %ebx, %eax + lea 32(%esi), %esi + dec %ecx + jne 1b + adcl $0, %eax +2: movl %edx, %ecx + andl $0x1c, %edx + je 4f + shrl $2, %edx # This clears CF +3: adcl (%esi), %eax + lea 4(%esi), %esi + dec %edx + jne 3b + adcl $0, %eax +4: andl $3, %ecx + jz 7f + cmpl $2, %ecx + jb 5f + movw (%esi),%cx + leal 2(%esi),%esi + je 6f + shll $16,%ecx +5: movb (%esi),%cl +6: addl %ecx,%eax + adcl $0, %eax +7: + popl %ebx + popl %esi + ret + +#else + +/* Version for PentiumII/PPro */ + +csum_partial: + pushl %esi + pushl %ebx + movl 20(%esp),%eax # Function arg: unsigned int sum + movl 16(%esp),%ecx # Function arg: int len + movl 12(%esp),%esi # Function arg: const unsigned char *buf + + testl $2, %esi + jnz 30f +10: + movl %ecx, %edx + movl %ecx, %ebx + andl $0x7c, %ebx + shrl $7, %ecx + addl %ebx,%esi + shrl $2, %ebx + negl %ebx + lea 45f(%ebx,%ebx,2), %ebx + testl %esi, %esi + jmp *%ebx + + # Handle 2-byte-aligned regions +20: addw (%esi), %ax + lea 2(%esi), %esi + adcl $0, %eax + jmp 10b + +30: subl $2, %ecx + ja 20b + je 32f + movzbl (%esi),%ebx # csumming 1 byte, 2-aligned + addl %ebx, %eax + adcl $0, %eax + jmp 80f +32: + addw (%esi), %ax # csumming 2 bytes, 2-aligned + adcl $0, %eax + jmp 80f + +40: + addl -128(%esi), %eax + adcl -124(%esi), %eax + adcl -120(%esi), %eax + adcl -116(%esi), %eax + adcl -112(%esi), %eax + adcl -108(%esi), %eax + adcl -104(%esi), %eax + adcl -100(%esi), %eax + adcl -96(%esi), %eax + adcl -92(%esi), %eax + adcl -88(%esi), %eax + adcl -84(%esi), %eax + adcl -80(%esi), %eax + adcl -76(%esi), %eax + adcl -72(%esi), %eax + adcl -68(%esi), %eax + adcl -64(%esi), %eax + adcl -60(%esi), %eax + adcl -56(%esi), %eax + adcl -52(%esi), %eax + adcl -48(%esi), %eax + adcl -44(%esi), %eax + adcl -40(%esi), %eax + adcl -36(%esi), %eax + adcl -32(%esi), %eax + adcl -28(%esi), %eax + adcl -24(%esi), %eax + adcl -20(%esi), %eax + adcl -16(%esi), %eax + adcl -12(%esi), %eax + adcl -8(%esi), %eax + adcl -4(%esi), %eax +45: + lea 128(%esi), %esi + adcl $0, %eax + dec %ecx + jge 40b + movl %edx, %ecx +50: andl $3, %ecx + jz 80f + + # Handle the last 1-3 bytes without jumping + notl %ecx # 1->2, 2->1, 3->0, higher bits are masked + movl $0xffffff,%ebx # by the shll and shrl instructions + shll $3,%ecx + shrl %cl,%ebx + andl -128(%esi),%ebx # esi is 4-aligned so should be ok + addl %ebx,%eax + adcl $0,%eax +80: + popl %ebx + popl %esi + ret + +#endif + +/* +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(y...) \ + 9999: y; \ + .section __ex_table, "a"; \ + .long 9999b, 6001f ; \ + .previous + +#define DST(y...) \ + 9999: y; \ + .section __ex_table, "a"; \ + .long 9999b, 6002f ; \ + .previous + +.align 4 + +#ifndef CONFIG_X86_USE_PPRO_CHECKSUM + +#define ARGBASE 16 +#define FP 12 + +csum_partial_copy_generic_i386: + subl $4,%esp + pushl %edi + pushl %esi + pushl %ebx + movl ARGBASE+16(%esp),%eax # sum + movl ARGBASE+12(%esp),%ecx # len + movl ARGBASE+4(%esp),%esi # src + movl ARGBASE+8(%esp),%edi # dst + + testl $2, %edi # Check alignment. + jz 2f # Jump if alignment is ok. + subl $2, %ecx # Alignment uses up two bytes. + jae 1f # Jump if we had at least two bytes. + addl $2, %ecx # ecx was < 2. Deal with it. + jmp 4f +SRC(1: movw (%esi), %bx ) + addl $2, %esi +DST( movw %bx, (%edi) ) + addl $2, %edi + addw %bx, %ax + adcl $0, %eax +2: + movl %ecx, FP(%esp) + shrl $5, %ecx + jz 2f + testl %esi, %esi +SRC(1: movl (%esi), %ebx ) +SRC( movl 4(%esi), %edx ) + adcl %ebx, %eax +DST( movl %ebx, (%edi) ) + adcl %edx, %eax +DST( movl %edx, 4(%edi) ) + +SRC( movl 8(%esi), %ebx ) +SRC( movl 12(%esi), %edx ) + adcl %ebx, %eax +DST( movl %ebx, 8(%edi) ) + adcl %edx, %eax +DST( movl %edx, 12(%edi) ) + +SRC( movl 16(%esi), %ebx ) +SRC( movl 20(%esi), %edx ) + adcl %ebx, %eax +DST( movl %ebx, 16(%edi) ) + adcl %edx, %eax +DST( movl %edx, 20(%edi) ) + +SRC( movl 24(%esi), %ebx ) +SRC( movl 28(%esi), %edx ) + adcl %ebx, %eax +DST( movl %ebx, 24(%edi) ) + adcl %edx, %eax +DST( movl %edx, 28(%edi) ) + + lea 32(%esi), %esi + lea 32(%edi), %edi + dec %ecx + jne 1b + adcl $0, %eax +2: movl FP(%esp), %edx + movl %edx, %ecx + andl $0x1c, %edx + je 4f + shrl $2, %edx # This clears CF +SRC(3: movl (%esi), %ebx ) + adcl %ebx, %eax +DST( movl %ebx, (%edi) ) + lea 4(%esi), %esi + lea 4(%edi), %edi + dec %edx + jne 3b + adcl $0, %eax +4: andl $3, %ecx + jz 7f + cmpl $2, %ecx + jb 5f +SRC( movw (%esi), %cx ) + leal 2(%esi), %esi +DST( movw %cx, (%edi) ) + leal 2(%edi), %edi + je 6f + shll $16,%ecx +SRC(5: movb (%esi), %cl ) +DST( movb %cl, (%edi) ) +6: addl %ecx, %eax + adcl $0, %eax +7: +5000: + +# Exception handler: +.section .fixup, "ax" + +6001: + movl ARGBASE+20(%esp), %ebx # src_err_ptr + movl $-EFAULT, (%ebx) + + # zero the complete destination - computing the rest + # is too much work + movl ARGBASE+8(%esp), %edi # dst + movl ARGBASE+12(%esp), %ecx # len + xorl %eax,%eax + rep ; stosb + + jmp 5000b + +6002: + movl ARGBASE+24(%esp), %ebx # dst_err_ptr + movl $-EFAULT,(%ebx) + jmp 5000b + +.previous + + popl %ebx + popl %esi + popl %edi + popl %ecx # equivalent to addl $4,%esp + ret + +#else + +/* Version for PentiumII/PPro */ + +#define ROUND1(x) \ + SRC(movl x(%esi), %ebx ) ; \ + addl %ebx, %eax ; \ + DST(movl %ebx, x(%edi) ) ; + +#define ROUND(x) \ + SRC(movl x(%esi), %ebx ) ; \ + adcl %ebx, %eax ; \ + DST(movl %ebx, x(%edi) ) ; + +#define ARGBASE 12 + +csum_partial_copy_generic_i386: + pushl %ebx + pushl %edi + pushl %esi + movl ARGBASE+4(%esp),%esi #src + movl ARGBASE+8(%esp),%edi #dst + movl ARGBASE+12(%esp),%ecx #len + movl ARGBASE+16(%esp),%eax #sum +# movl %ecx, %edx + movl %ecx, %ebx + movl %esi, %edx + shrl $6, %ecx + andl $0x3c, %ebx + negl %ebx + subl %ebx, %esi + subl %ebx, %edi + lea -1(%esi),%edx + andl $-32,%edx + lea 3f(%ebx,%ebx), %ebx + testl %esi, %esi + jmp *%ebx +1: addl $64,%esi + addl $64,%edi + SRC(movb -32(%edx),%bl) ; SRC(movb (%edx),%bl) + ROUND1(-64) ROUND(-60) ROUND(-56) ROUND(-52) + ROUND (-48) ROUND(-44) ROUND(-40) ROUND(-36) + ROUND (-32) ROUND(-28) ROUND(-24) ROUND(-20) + ROUND (-16) ROUND(-12) ROUND(-8) ROUND(-4) +3: adcl $0,%eax + addl $64, %edx + dec %ecx + jge 1b +4: movl ARGBASE+12(%esp),%edx #len + andl $3, %edx + jz 7f + cmpl $2, %edx + jb 5f +SRC( movw (%esi), %dx ) + leal 2(%esi), %esi +DST( movw %dx, (%edi) ) + leal 2(%edi), %edi + je 6f + shll $16,%edx +5: +SRC( movb (%esi), %dl ) +DST( movb %dl, (%edi) ) +6: addl %edx, %eax + adcl $0, %eax +7: +.section .fixup, "ax" +6001: movl ARGBASE+20(%esp), %ebx # src_err_ptr + movl $-EFAULT, (%ebx) + # zero the complete destination (computing the rest is too much work) + movl ARGBASE+8(%esp),%edi # dst + movl ARGBASE+12(%esp),%ecx # len + xorl %eax,%eax + rep; stosb + jmp 7b +6002: movl ARGBASE+24(%esp), %ebx # dst_err_ptr + movl $-EFAULT, (%ebx) + jmp 7b +.previous + + popl %esi + popl %edi + popl %ebx + ret + +#undef ROUND +#undef ROUND1 + +#endif |