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authorIngo Molnar <mingo@elte.hu>2009-06-17 12:52:15 +0200
committerIngo Molnar <mingo@elte.hu>2009-06-17 12:56:49 +0200
commiteadb8a091b27a840de7450f84ecff5ef13476424 (patch)
tree58c3782d40def63baa8167f3d31e3048cb4c7660 /include/asm-generic/checksum.h
parenthw-breakpoints: fix undeclared ksym_tracer_mutex (diff)
parentMerge branch 'next-i2c' of git://aeryn.fluff.org.uk/bjdooks/linux (diff)
downloadlinux-eadb8a091b27a840de7450f84ecff5ef13476424.tar.xz
linux-eadb8a091b27a840de7450f84ecff5ef13476424.zip
Merge branch 'linus' into tracing/hw-breakpoints
Conflicts: arch/x86/Kconfig arch/x86/kernel/traps.c arch/x86/power/cpu.c arch/x86/power/cpu_32.c kernel/Makefile Semantic conflict: arch/x86/kernel/hw_breakpoint.c Merge reason: Resolve the conflicts, move from put_cpu_no_sched() to put_cpu() in arch/x86/kernel/hw_breakpoint.c. Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'include/asm-generic/checksum.h')
-rw-r--r--include/asm-generic/checksum.h79
1 files changed, 79 insertions, 0 deletions
diff --git a/include/asm-generic/checksum.h b/include/asm-generic/checksum.h
new file mode 100644
index 000000000000..4647c762d970
--- /dev/null
+++ b/include/asm-generic/checksum.h
@@ -0,0 +1,79 @@
+#ifndef __ASM_GENERIC_CHECKSUM_H
+#define __ASM_GENERIC_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
+ */
+extern __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
+ */
+extern __wsum csum_partial_copy(const void *src, void *dst, int len, __wsum sum);
+
+/*
+ * the same as csum_partial_copy, but copies from user space.
+ *
+ * here even more important to align src and dst on a 32-bit (or even
+ * better 64-bit) boundary
+ */
+extern __wsum csum_partial_copy_from_user(const void __user *src, void *dst,
+ int len, __wsum sum, int *csum_err);
+
+#define csum_partial_copy_nocheck(src, dst, len, sum) \
+ csum_partial_copy((src), (dst), (len), (sum))
+
+/*
+ * This is a version of ip_compute_csum() optimized for IP headers,
+ * which always checksum on 4 octet boundaries.
+ */
+extern __sum16 ip_fast_csum(const void *iph, unsigned int ihl);
+
+/*
+ * Fold a partial checksum
+ */
+static inline __sum16 csum_fold(__wsum csum)
+{
+ u32 sum = (__force u32)csum;
+ sum = (sum & 0xffff) + (sum >> 16);
+ sum = (sum & 0xffff) + (sum >> 16);
+ return (__force __sum16)~sum;
+}
+
+#ifndef csum_tcpudp_nofold
+/*
+ * computes the checksum of the TCP/UDP pseudo-header
+ * returns a 16-bit checksum, already complemented
+ */
+extern __wsum
+csum_tcpudp_nofold(__be32 saddr, __be32 daddr, unsigned short len,
+ unsigned short proto, __wsum sum);
+#endif
+
+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
+ */
+extern __sum16 ip_compute_csum(const void *buff, int len);
+
+#endif /* __ASM_GENERIC_CHECKSUM_H */