1 files changed, 148 insertions, 0 deletions

diff --git a/arch/parisc/lib/checksum.c b/arch/parisc/lib/checksum.c
new file mode 100644
index 000000000000..8a1e08068e7d
--- /dev/null
+++ b/arch/parisc/lib/checksum.c
@@ -0,0 +1,148 @@
+/*
+ * 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.
+ *
+ *              MIPS specific IP/TCP/UDP checksumming routines
+ *
+ * Authors:     Ralf Baechle, <ralf@waldorf-gmbh.de>
+ *              Lots of code moved from tcp.c and ip.c; see those files
+ *              for more names.
+ *
+ *              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.
+ *
+ * $Id: checksum.c,v 1.3 1997/12/01 17:57:34 ralf Exp $
+ */
+#include <linux/module.h>
+#include <linux/types.h>
+
+#include <net/checksum.h>
+#include <asm/byteorder.h>
+#include <asm/string.h>
+#include <asm/uaccess.h>
+
+#define addc(_t,_r)                     \
+        __asm__ __volatile__ (          \
+"       add             %0, %1, %0\n"   \
+"       addc            %0, %%r0, %0\n" \
+        : "=r"(_t)                      \
+        : "r"(_r), "0"(_t));
+
+static inline unsigned short from32to16(unsigned int x)
+{
+        /* 32 bits --> 16 bits + carry */
+        x = (x & 0xffff) + (x >> 16);
+        /* 16 bits + carry --> 16 bits including carry */
+        x = (x & 0xffff) + (x >> 16);
+        return (unsigned short)x;
+}
+
+static inline unsigned int do_csum(const unsigned char * buff, int len)
+{
+        int odd, count;
+        unsigned int result = 0;
+
+        if (len <= 0)
+                goto out;
+        odd = 1 & (unsigned long) buff;
+        if (odd) {
+                result = be16_to_cpu(*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) {
+                        while (count >= 4) {
+                                unsigned int r1, r2, r3, r4;
+                                r1 = *(unsigned int *)(buff + 0);
+                                r2 = *(unsigned int *)(buff + 4);
+                                r3 = *(unsigned int *)(buff + 8);
+                                r4 = *(unsigned int *)(buff + 12);
+                                addc(result, r1);
+                                addc(result, r2);
+                                addc(result, r3);
+                                addc(result, r4);
+                                count -= 4;
+                                buff += 16;
+                        }
+                        while (count) {
+                                unsigned int w = *(unsigned int *) buff;
+                                count--;
+                                buff += 4;
+                                addc(result, w);
+                        }
+                        result = (result & 0xffff) + (result >> 16);
+                }
+                if (len & 2) {
+                        result += *(unsigned short *) buff;
+                        buff += 2;
+                }
+        }
+        if (len & 1)
+                result += le16_to_cpu(*buff);
+        result = from32to16(result);
+        if (odd)
+                result = swab16(result);
+out:
+        return result;
+}
+
+/*
+ * computes a partial checksum, e.g. for TCP/UDP fragments
+ */
+unsigned int csum_partial(const unsigned char *buff, int len, unsigned int sum)
+{
+        unsigned int result = do_csum(buff, len);
+        addc(result, sum);
+        return from32to16(result);
+}
+
+EXPORT_SYMBOL(csum_partial);
+
+/*
+ * copy while checksumming, otherwise like csum_partial
+ */
+unsigned int csum_partial_copy_nocheck(const unsigned char *src, unsigned char *dst,
+                                       int len, unsigned int sum)
+{
+        /*
+         * It's 2:30 am and I don't feel like doing it real ...
+         * This is lots slower than the real thing (tm)
+         */
+        sum = csum_partial(src, len, sum);
+        memcpy(dst, src, len);
+
+        return sum;
+}
+EXPORT_SYMBOL(csum_partial_copy_nocheck);
+
+/*
+ * Copy from userspace and compute checksum.  If we catch an exception
+ * then zero the rest of the buffer.
+ */
+unsigned int csum_partial_copy_from_user(const unsigned char __user *src,
+                                        unsigned char *dst, int len,
+                                        unsigned int sum, int *err_ptr)
+{
+        int missing;
+
+        missing = copy_from_user(dst, src, len);
+        if (missing) {
+                memset(dst + len - missing, 0, missing);
+                *err_ptr = -EFAULT;
+        }
+                
+        return csum_partial(dst, len, sum);
+}
+EXPORT_SYMBOL(csum_partial_copy_from_user);