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-rw-r--r--include/asm-powerpc/checksum.h132
1 files changed, 132 insertions, 0 deletions
diff --git a/include/asm-powerpc/checksum.h b/include/asm-powerpc/checksum.h
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+++ b/include/asm-powerpc/checksum.h
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+#ifndef _ASM_POWERPC_CHECKSUM_H
+#define _ASM_POWERPC_CHECKSUM_H
+
+/*
+ * 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.
+ */
+
+/*
+ * This is a version of ip_compute_csum() optimized for IP headers,
+ * which always checksum on 4 octet boundaries. ihl is the number
+ * of 32-bit words and is always >= 5.
+ */
+extern unsigned short ip_fast_csum(unsigned char * iph, unsigned int ihl);
+
+/*
+ * computes the checksum of the TCP/UDP pseudo-header
+ * returns a 16-bit checksum, already complemented
+ */
+extern unsigned short csum_tcpudp_magic(unsigned long saddr,
+ unsigned long daddr,
+ unsigned short len,
+ unsigned short proto,
+ unsigned int sum);
+
+/*
+ * computes the checksum of a memory block at buff, length len,
+ * and adds in "sum" (32-bit)
+ *
+ * returns a 32-bit number suitable for feeding into itself
+ * or csum_tcpudp_magic
+ *
+ * this function must be called with even lengths, except
+ * for the last fragment, which may be odd
+ *
+ * it's best to have buff aligned on a 32-bit boundary
+ */
+extern unsigned int csum_partial(const unsigned char * buff, int len,
+ unsigned int sum);
+
+/*
+ * 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 (if that pointer is not
+ * NULL), and, for an error on src, zeroes the rest of dst.
+ *
+ * Like csum_partial, this must be called with even lengths,
+ * except for the last fragment.
+ */
+extern unsigned int csum_partial_copy_generic(const char *src, char *dst,
+ int len, unsigned int sum,
+ int *src_err, int *dst_err);
+/*
+ * the same as csum_partial, but copies from src to dst while it
+ * checksums.
+ */
+unsigned int csum_partial_copy_nocheck(const char *src,
+ char *dst,
+ int len,
+ unsigned int sum);
+
+#define csum_partial_copy_from_user(src, dst, len, sum, errp) \
+ csum_partial_copy_generic((src), (dst), (len), (sum), (errp), NULL)
+
+#define csum_partial_copy_nocheck(src, dst, len, sum) \
+ csum_partial_copy_generic((src), (dst), (len), (sum), NULL, NULL)
+
+
+/*
+ * turns a 32-bit partial checksum (e.g. from csum_partial) into a
+ * 1's complement 16-bit checksum.
+ */
+static inline unsigned int csum_fold(unsigned int sum)
+{
+ unsigned int tmp;
+
+ /* swap the two 16-bit halves of sum */
+ __asm__("rlwinm %0,%1,16,0,31" : "=r" (tmp) : "r" (sum));
+ /* if there is a carry from adding the two 16-bit halves,
+ it will carry from the lower half into the upper half,
+ giving us the correct sum in the upper half. */
+ sum = ~(sum + tmp) >> 16;
+ return sum;
+}
+
+/*
+ * this routine is used for miscellaneous IP-like checksums, mainly
+ * in icmp.c
+ */
+static inline unsigned short ip_compute_csum(unsigned char * buff, int len)
+{
+ return csum_fold(csum_partial(buff, len, 0));
+}
+
+#ifdef __powerpc64__
+static inline u32 csum_tcpudp_nofold(u32 saddr,
+ u32 daddr,
+ unsigned short len,
+ unsigned short proto,
+ unsigned int sum)
+{
+ unsigned long s = sum;
+
+ s += saddr;
+ s += daddr;
+ s += (proto << 16) + len;
+ s += (s >> 32);
+ return (u32) s;
+}
+#else
+static inline unsigned long csum_tcpudp_nofold(unsigned long saddr,
+ unsigned long daddr,
+ unsigned short len,
+ unsigned short proto,
+ unsigned int sum)
+{
+ __asm__("\n\
+ addc %0,%0,%1 \n\
+ adde %0,%0,%2 \n\
+ adde %0,%0,%3 \n\
+ addze %0,%0 \n\
+ "
+ : "=r" (sum)
+ : "r" (daddr), "r"(saddr), "r"((proto<<16)+len), "0"(sum));
+ return sum;
+}
+
+#endif
+#endif