Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / arch / frv / lib / checksum.c

diff --git a/kernel/arch/frv/lib/checksum.c b/kernel/arch/frv/lib/checksum.c
new file mode 100644 (file)
index 0000000..44e16d5
--- /dev/null
+++ b/kernel/arch/frv/lib/checksum.c
@@ -0,0 +1,166 @@
+/*
+ * 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.
+ */
+
+/* Revised by Kenneth Albanowski for m68knommu. Basic problem: unaligned access kills, so most
+   of the assembly has to go. */
+
+#include <net/checksum.h>
+#include <linux/module.h>
+
+static inline unsigned short from32to16(unsigned long x)
+{
+       /* add up 16-bit and 16-bit for 16+c bit */
+       x = (x & 0xffff) + (x >> 16);
+       /* add up carry.. */
+       x = (x & 0xffff) + (x >> 16);
+       return x;
+}
+
+static unsigned long do_csum(const unsigned char * buff, int len)
+{
+       int odd, count;
+       unsigned long result = 0;
+
+       if (len <= 0)
+               goto out;
+       odd = 1 & (unsigned long) buff;
+       if (odd) {
+               result = *buff;
+               len--;
+               buff++;
+       }
+       count = len >> 1;               /* nr of 16-bit words.. */
+       if (count) {
+               if (2 & (unsigned long) buff) {
+                       result += *(unsigned short *) buff;
+                       count--;
+                       len -= 2;
+                       buff += 2;
+               }
+               count >>= 1;            /* nr of 32-bit words.. */
+               if (count) {
+                       unsigned long carry = 0;
+                       do {
+                               unsigned long w = *(unsigned long *) buff;
+                               count--;
+                               buff += 4;
+                               result += carry;
+                               result += w;
+                               carry = (w > result);
+                       } while (count);
+                       result += carry;
+                       result = (result & 0xffff) + (result >> 16);
+               }
+               if (len & 2) {
+                       result += *(unsigned short *) buff;
+                       buff += 2;
+               }
+       }
+       if (len & 1)
+               result += (*buff << 8);
+       result = from32to16(result);
+       if (odd)
+               result = ((result >> 8) & 0xff) | ((result & 0xff) << 8);
+out:
+       return result;
+}
+
+/*
+ * 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
+ */
+__wsum csum_partial(const void *buff, int len, __wsum sum)
+{
+       unsigned int result = do_csum(buff, len);
+
+       /* add in old sum, and carry.. */
+       result += (__force u32)sum;
+       if ((__force u32)sum > result)
+               result += 1;
+       return (__force __wsum)result;
+}
+
+EXPORT_SYMBOL(csum_partial);
+
+/*
+ * this routine is used for miscellaneous IP-like checksums, mainly
+ * in icmp.c
+ */
+__sum16 ip_compute_csum(const void *buff, int len)
+{
+       return (__force __sum16)~do_csum(buff, len);
+}
+
+EXPORT_SYMBOL(ip_compute_csum);
+
+/*
+ * copy from fs while checksumming, otherwise like csum_partial
+ */
+__wsum
+csum_partial_copy_from_user(const void __user *src, void *dst,
+                           int len, __wsum sum, int *csum_err)
+{
+       int rem;
+
+       if (csum_err)
+               *csum_err = 0;
+
+       rem = copy_from_user(dst, src, len);
+       if (rem != 0) {
+               if (csum_err)
+                       *csum_err = -EFAULT;
+               memset(dst + len - rem, 0, rem);
+               len = rem;
+       }
+
+       return csum_partial(dst, len, sum);
+}
+
+EXPORT_SYMBOL(csum_partial_copy_from_user);
+
+/*
+ * copy from ds while checksumming, otherwise like csum_partial
+ */
+__wsum
+csum_partial_copy_nocheck(const void *src, void *dst, int len, __wsum sum)
+{
+       memcpy(dst, src, len);
+       return csum_partial(dst, len, sum);
+}
+
+EXPORT_SYMBOL(csum_partial_copy_nocheck);