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-rw-r--r--arch/powerpc/lib/checksum.S225
1 files changed, 225 insertions, 0 deletions
diff --git a/arch/powerpc/lib/checksum.S b/arch/powerpc/lib/checksum.S
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+/*
+ * This file contains assembly-language implementations
+ * of IP-style 1's complement checksum routines.
+ *
+ * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
+ *
+ * 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.
+ *
+ * Severely hacked about by Paul Mackerras (paulus@cs.anu.edu.au).
+ */
+
+#include <linux/sys.h>
+#include <asm/processor.h>
+#include <asm/errno.h>
+#include <asm/ppc_asm.h>
+
+ .text
+
+/*
+ * ip_fast_csum(buf, len) -- Optimized for IP header
+ * len is in words and is always >= 5.
+ */
+_GLOBAL(ip_fast_csum)
+ lwz r0,0(r3)
+ lwzu r5,4(r3)
+ addic. r4,r4,-2
+ addc r0,r0,r5
+ mtctr r4
+ blelr-
+1: lwzu r4,4(r3)
+ adde r0,r0,r4
+ bdnz 1b
+ addze r0,r0 /* add in final carry */
+ rlwinm r3,r0,16,0,31 /* fold two halves together */
+ add r3,r0,r3
+ not r3,r3
+ srwi r3,r3,16
+ blr
+
+/*
+ * Compute checksum of TCP or UDP pseudo-header:
+ * csum_tcpudp_magic(saddr, daddr, len, proto, sum)
+ */
+_GLOBAL(csum_tcpudp_magic)
+ rlwimi r5,r6,16,0,15 /* put proto in upper half of len */
+ addc r0,r3,r4 /* add 4 32-bit words together */
+ adde r0,r0,r5
+ adde r0,r0,r7
+ addze r0,r0 /* add in final carry */
+ rlwinm r3,r0,16,0,31 /* fold two halves together */
+ add r3,r0,r3
+ not r3,r3
+ srwi r3,r3,16
+ blr
+
+/*
+ * computes the checksum of a memory block at buff, length len,
+ * and adds in "sum" (32-bit)
+ *
+ * csum_partial(buff, len, sum)
+ */
+_GLOBAL(csum_partial)
+ addic r0,r5,0
+ subi r3,r3,4
+ srwi. r6,r4,2
+ beq 3f /* if we're doing < 4 bytes */
+ andi. r5,r3,2 /* Align buffer to longword boundary */
+ beq+ 1f
+ lhz r5,4(r3) /* do 2 bytes to get aligned */
+ addi r3,r3,2
+ subi r4,r4,2
+ addc r0,r0,r5
+ srwi. r6,r4,2 /* # words to do */
+ beq 3f
+1: mtctr r6
+2: lwzu r5,4(r3) /* the bdnz has zero overhead, so it should */
+ adde r0,r0,r5 /* be unnecessary to unroll this loop */
+ bdnz 2b
+ andi. r4,r4,3
+3: cmpwi 0,r4,2
+ blt+ 4f
+ lhz r5,4(r3)
+ addi r3,r3,2
+ subi r4,r4,2
+ adde r0,r0,r5
+4: cmpwi 0,r4,1
+ bne+ 5f
+ lbz r5,4(r3)
+ slwi r5,r5,8 /* Upper byte of word */
+ adde r0,r0,r5
+5: addze r3,r0 /* add in final carry */
+ blr
+
+/*
+ * Computes the checksum of a memory block at src, length len,
+ * and adds in "sum" (32-bit), while copying the block to dst.
+ * If an access exception occurs on src or dst, it stores -EFAULT
+ * to *src_err or *dst_err respectively, and (for an error on
+ * src) zeroes the rest of dst.
+ *
+ * csum_partial_copy_generic(src, dst, len, sum, src_err, dst_err)
+ */
+_GLOBAL(csum_partial_copy_generic)
+ addic r0,r6,0
+ subi r3,r3,4
+ subi r4,r4,4
+ srwi. r6,r5,2
+ beq 3f /* if we're doing < 4 bytes */
+ andi. r9,r4,2 /* Align dst to longword boundary */
+ beq+ 1f
+81: lhz r6,4(r3) /* do 2 bytes to get aligned */
+ addi r3,r3,2
+ subi r5,r5,2
+91: sth r6,4(r4)
+ addi r4,r4,2
+ addc r0,r0,r6
+ srwi. r6,r5,2 /* # words to do */
+ beq 3f
+1: srwi. r6,r5,4 /* # groups of 4 words to do */
+ beq 10f
+ mtctr r6
+71: lwz r6,4(r3)
+72: lwz r9,8(r3)
+73: lwz r10,12(r3)
+74: lwzu r11,16(r3)
+ adde r0,r0,r6
+75: stw r6,4(r4)
+ adde r0,r0,r9
+76: stw r9,8(r4)
+ adde r0,r0,r10
+77: stw r10,12(r4)
+ adde r0,r0,r11
+78: stwu r11,16(r4)
+ bdnz 71b
+10: rlwinm. r6,r5,30,30,31 /* # words left to do */
+ beq 13f
+ mtctr r6
+82: lwzu r9,4(r3)
+92: stwu r9,4(r4)
+ adde r0,r0,r9
+ bdnz 82b
+13: andi. r5,r5,3
+3: cmpwi 0,r5,2
+ blt+ 4f
+83: lhz r6,4(r3)
+ addi r3,r3,2
+ subi r5,r5,2
+93: sth r6,4(r4)
+ addi r4,r4,2
+ adde r0,r0,r6
+4: cmpwi 0,r5,1
+ bne+ 5f
+84: lbz r6,4(r3)
+94: stb r6,4(r4)
+ slwi r6,r6,8 /* Upper byte of word */
+ adde r0,r0,r6
+5: addze r3,r0 /* add in final carry */
+ blr
+
+/* These shouldn't go in the fixup section, since that would
+ cause the ex_table addresses to get out of order. */
+
+src_error_4:
+ mfctr r6 /* update # bytes remaining from ctr */
+ rlwimi r5,r6,4,0,27
+ b 79f
+src_error_1:
+ li r6,0
+ subi r5,r5,2
+95: sth r6,4(r4)
+ addi r4,r4,2
+79: srwi. r6,r5,2
+ beq 3f
+ mtctr r6
+src_error_2:
+ li r6,0
+96: stwu r6,4(r4)
+ bdnz 96b
+3: andi. r5,r5,3
+ beq src_error
+src_error_3:
+ li r6,0
+ mtctr r5
+ addi r4,r4,3
+97: stbu r6,1(r4)
+ bdnz 97b
+src_error:
+ cmpwi 0,r7,0
+ beq 1f
+ li r6,-EFAULT
+ stw r6,0(r7)
+1: addze r3,r0
+ blr
+
+dst_error:
+ cmpwi 0,r8,0
+ beq 1f
+ li r6,-EFAULT
+ stw r6,0(r8)
+1: addze r3,r0
+ blr
+
+.section __ex_table,"a"
+ .long 81b,src_error_1
+ .long 91b,dst_error
+ .long 71b,src_error_4
+ .long 72b,src_error_4
+ .long 73b,src_error_4
+ .long 74b,src_error_4
+ .long 75b,dst_error
+ .long 76b,dst_error
+ .long 77b,dst_error
+ .long 78b,dst_error
+ .long 82b,src_error_2
+ .long 92b,dst_error
+ .long 83b,src_error_3
+ .long 93b,dst_error
+ .long 84b,src_error_3
+ .long 94b,dst_error
+ .long 95b,dst_error
+ .long 96b,dst_error
+ .long 97b,dst_error