1 files changed, 191 insertions, 0 deletions

diff --git a/include/asm-x86/checksum_32.h b/include/asm-x86/checksum_32.h
new file mode 100644
index 000000000000..75194abbe8ee
--- /dev/null
+++ b/include/asm-x86/checksum_32.h
@@ -0,0 +1,191 @@
+#ifndef _I386_CHECKSUM_H
+#define _I386_CHECKSUM_H
+
+#include <linux/in6.h>
+
+#include <asm/uaccess.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
+ */
+asmlinkage __wsum csum_partial(const void *buff, int len, __wsum sum);
+
+/*
+ * the same as csum_partial, but copies from src while it
+ * checksums, and handles user-space pointer exceptions correctly, when needed.
+ *
+ * here even more important to align src and dst on a 32-bit (or even
+ * better 64-bit) boundary
+ */
+
+asmlinkage __wsum csum_partial_copy_generic(const void *src, void *dst,
+                                                  int len, __wsum sum, int *src_err_ptr, int *dst_err_ptr);
+
+/*
+ *      Note: when you get a NULL pointer exception here this means someone
+ *      passed in an incorrect kernel address to one of these functions.
+ *
+ *      If you use these functions directly please don't forget the
+ *      access_ok().
+ */
+static __inline__
+__wsum csum_partial_copy_nocheck (const void *src, void *dst,
+                                        int len, __wsum sum)
+{
+        return csum_partial_copy_generic ( src, dst, len, sum, NULL, NULL);
+}
+
+static __inline__
+__wsum csum_partial_copy_from_user(const void __user *src, void *dst,
+                                                int len, __wsum sum, int *err_ptr)
+{
+        might_sleep();
+        return csum_partial_copy_generic((__force void *)src, dst,
+                                        len, sum, err_ptr, NULL);
+}
+
+/*
+ *      This is a version of ip_compute_csum() optimized for IP headers,
+ *      which always checksum on 4 octet boundaries.
+ *
+ *      By Jorge Cwik <jorge@laser.satlink.net>, adapted for linux by
+ *      Arnt Gulbrandsen.
+ */
+static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
+{
+        unsigned int sum;
+
+        __asm__ __volatile__(
+            "movl (%1), %0      ;\n"
+            "subl $4, %2        ;\n"
+            "jbe 2f             ;\n"
+            "addl 4(%1), %0     ;\n"
+            "adcl 8(%1), %0     ;\n"
+            "adcl 12(%1), %0    ;\n"
+"1:         adcl 16(%1), %0     ;\n"
+            "lea 4(%1), %1      ;\n"
+            "decl %2            ;\n"
+            "jne 1b             ;\n"
+            "adcl $0, %0        ;\n"
+            "movl %0, %2        ;\n"
+            "shrl $16, %0       ;\n"
+            "addw %w2, %w0      ;\n"
+            "adcl $0, %0        ;\n"
+            "notl %0            ;\n"
+"2:                             ;\n"
+        /* Since the input registers which are loaded with iph and ihl
+           are modified, we must also specify them as outputs, or gcc
+           will assume they contain their original values. */
+        : "=r" (sum), "=r" (iph), "=r" (ihl)
+        : "1" (iph), "2" (ihl)
+        : "memory");
+        return (__force __sum16)sum;
+}
+
+/*
+ *      Fold a partial checksum
+ */
+
+static inline __sum16 csum_fold(__wsum sum)
+{
+        __asm__(
+                "addl %1, %0            ;\n"
+                "adcl $0xffff, %0       ;\n"
+                : "=r" (sum)
+                : "r" ((__force u32)sum << 16),
+                  "0" ((__force u32)sum & 0xffff0000)
+        );
+        return (__force __sum16)(~(__force u32)sum >> 16);
+}
+
+static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
+                                           unsigned short len,
+                                           unsigned short proto,
+                                           __wsum sum)
+{
+    __asm__(
+        "addl %1, %0    ;\n"
+        "adcl %2, %0    ;\n"
+        "adcl %3, %0    ;\n"
+        "adcl $0, %0    ;\n"
+        : "=r" (sum)
+        : "g" (daddr), "g"(saddr), "g"((len + proto) << 8), "0"(sum));
+    return sum;
+}
+
+/*
+ * 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));
+}
+
+#define _HAVE_ARCH_IPV6_CSUM
+static __inline__ __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
+                                          const struct in6_addr *daddr,
+                                          __u32 len, unsigned short proto,
+                                          __wsum sum)
+{
+        __asm__(
+                "addl 0(%1), %0         ;\n"
+                "adcl 4(%1), %0         ;\n"
+                "adcl 8(%1), %0         ;\n"
+                "adcl 12(%1), %0        ;\n"
+                "adcl 0(%2), %0         ;\n"
+                "adcl 4(%2), %0         ;\n"
+                "adcl 8(%2), %0         ;\n"
+                "adcl 12(%2), %0        ;\n"
+                "adcl %3, %0            ;\n"
+                "adcl %4, %0            ;\n"
+                "adcl $0, %0            ;\n"
+                : "=&r" (sum)
+                : "r" (saddr), "r" (daddr),
+                  "r"(htonl(len)), "r"(htonl(proto)), "0"(sum));
+
+        return csum_fold(sum);
+}
+
+/*
+ *      Copy and checksum to user
+ */
+#define HAVE_CSUM_COPY_USER
+static __inline__ __wsum csum_and_copy_to_user(const void *src,
+                                                     void __user *dst,
+                                                     int len, __wsum sum,
+                                                     int *err_ptr)
+{
+        might_sleep();
+        if (access_ok(VERIFY_WRITE, dst, len))
+                return csum_partial_copy_generic(src, (__force void *)dst, len, sum, NULL, err_ptr);
+
+        if (len)
+                *err_ptr = -EFAULT;
+
+        return (__force __wsum)-1; /* invalid checksum */
+}
+
+#endif