aboutsummaryrefslogtreecommitdiff
path: root/arch/cris/include/asm/checksum.h
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2008-11-01 09:51:51 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-11-01 09:51:51 -0700
commit0242909a6135e10a28822c64f9ad50fdad52757c (patch)
treec5f9c8abe95a65433e6ac356871f2379c02488fe /arch/cris/include/asm/checksum.h
parent0a6d2fac615972142715d736289abeeb7382e81d (diff)
parent556dcee7b829e5c350c3ffdbdb87a8b15aa3c5d3 (diff)
Merge branch 'cris_move' of git://www.jni.nu/cris
* 'cris_move' of git://www.jni.nu/cris: [CRIS] Move header files from include to arch/cris/include. [CRISv32] Remove warning in io.h
Diffstat (limited to 'arch/cris/include/asm/checksum.h')
-rw-r--r--arch/cris/include/asm/checksum.h83
1 files changed, 83 insertions, 0 deletions
diff --git a/arch/cris/include/asm/checksum.h b/arch/cris/include/asm/checksum.h
new file mode 100644
index 00000000000..75dcb77d6cb
--- /dev/null
+++ b/arch/cris/include/asm/checksum.h
@@ -0,0 +1,83 @@
+/* TODO: csum_tcpudp_magic could be speeded up, and csum_fold as well */
+
+#ifndef _CRIS_CHECKSUM_H
+#define _CRIS_CHECKSUM_H
+
+#include <arch/checksum.h>
+
+/*
+ * 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);
+
+/*
+ * the same as csum_partial, but copies from src while it
+ * checksums
+ *
+ * here even more important to align src and dst on a 32-bit (or even
+ * better 64-bit) boundary
+ */
+
+__wsum csum_partial_copy_nocheck(const void *src, void *dst,
+ int len, __wsum sum);
+
+/*
+ * Fold a partial checksum into a word
+ */
+
+static inline __sum16 csum_fold(__wsum csum)
+{
+ u32 sum = (__force u32)csum;
+ sum = (sum & 0xffff) + (sum >> 16); /* add in end-around carry */
+ sum = (sum & 0xffff) + (sum >> 16); /* add in end-around carry */
+ return (__force __sum16)~sum;
+}
+
+extern __wsum csum_partial_copy_from_user(const void __user *src, void *dst,
+ int len, __wsum sum,
+ int *errptr);
+
+/*
+ * This is a version of ip_compute_csum() optimized for IP headers,
+ * which always checksum on 4 octet boundaries.
+ *
+ */
+
+static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
+{
+ return csum_fold(csum_partial(iph, ihl * 4, 0));
+}
+
+/*
+ * computes the checksum of the TCP/UDP pseudo-header
+ * returns a 16-bit checksum, already complemented
+ */
+
+static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
+ unsigned short len,
+ unsigned short proto,
+ __wsum sum)
+{
+ return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
+}
+
+/*
+ * this routine is used for miscellaneous IP-like checksums, mainly
+ * in icmp.c
+ */
+
+static inline __sum16 ip_compute_csum(const void *buff, int len)
+{
+ return csum_fold (csum_partial(buff, len, 0));
+}
+
+#endif