1 files changed, 156 insertions, 0 deletions

diff --git a/include/asm-avr32/checksum.h b/include/asm-avr32/checksum.h
new file mode 100644
index 000000000000..41b7af09edc4
--- /dev/null
+++ b/include/asm-avr32/checksum.h
@@ -0,0 +1,156 @@
+/*
+ * Copyright (C) 2004-2006 Atmel Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#ifndef __ASM_AVR32_CHECKSUM_H
+#define __ASM_AVR32_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
+ */
+unsigned int csum_partial(const unsigned char * buff, int len,
+                          unsigned int 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
+ */
+unsigned int csum_partial_copy_generic(const char *src, char *dst, int len,
+                                       int 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
+ *      verify_area().
+ */
+static inline
+unsigned int csum_partial_copy_nocheck(const char *src, char *dst,
+                                       int len, int sum)
+{
+        return csum_partial_copy_generic(src, dst, len, sum, NULL, NULL);
+}
+
+static inline
+unsigned int csum_partial_copy_from_user (const char __user *src, char *dst,
+                                          int len, int sum, int *err_ptr)
+{
+        return csum_partial_copy_generic((const char __force *)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.
+ */
+static inline unsigned short ip_fast_csum(unsigned char *iph,
+                                          unsigned int ihl)
+{
+        unsigned int sum, tmp;
+
+        __asm__ __volatile__(
+                "       ld.w    %0, %1++\n"
+                "       ld.w    %3, %1++\n"
+                "       sub     %2, 4\n"
+                "       add     %0, %3\n"
+                "       ld.w    %3, %1++\n"
+                "       adc     %0, %0, %3\n"
+                "       ld.w    %3, %1++\n"
+                "       adc     %0, %0, %3\n"
+                "       acr     %0\n"
+                "1:     ld.w    %3, %1++\n"
+                "       add     %0, %3\n"
+                "       acr     %0\n"
+                "       sub     %2, 1\n"
+                "       brne    1b\n"
+                "       lsl     %3, %0, 16\n"
+                "       andl    %0, 0\n"
+                "       mov     %2, 0xffff\n"
+                "       add     %0, %3\n"
+                "       adc     %0, %0, %2\n"
+                "       com     %0\n"
+                "       lsr     %0, 16\n"
+                : "=r"(sum), "=r"(iph), "=r"(ihl), "=r"(tmp)
+                : "1"(iph), "2"(ihl)
+                : "memory", "cc");
+        return sum;
+}
+
+/*
+ *      Fold a partial checksum
+ */
+
+static inline unsigned int csum_fold(unsigned int sum)
+{
+        unsigned int tmp;
+
+        asm("   bfextu  %1, %0, 0, 16\n"
+            "   lsr     %0, 16\n"
+            "   add     %0, %1\n"
+            "   bfextu  %1, %0, 16, 16\n"
+            "   add     %0, %1"
+            : "=&r"(sum), "=&r"(tmp)
+            : "0"(sum));
+
+        return ~sum;
+}
+
+static inline unsigned long csum_tcpudp_nofold(unsigned long saddr,
+                                               unsigned long daddr,
+                                               unsigned short len,
+                                               unsigned short proto,
+                                               unsigned int sum)
+{
+        asm("   add     %0, %1\n"
+            "   adc     %0, %0, %2\n"
+            "   adc     %0, %0, %3\n"
+            "   acr     %0"
+            : "=r"(sum)
+            : "r"(daddr), "r"(saddr), "r"(ntohs(len) | (proto << 16)),
+              "0"(sum)
+            : "cc");
+
+        return sum;
+}
+
+/*
+ * computes the checksum of the TCP/UDP pseudo-header
+ * returns a 16-bit checksum, already complemented
+ */
+static inline unsigned short int csum_tcpudp_magic(unsigned long saddr,
+                                                   unsigned long daddr,
+                                                   unsigned short len,
+                                                   unsigned short proto,
+                                                   unsigned int 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 unsigned short ip_compute_csum(unsigned char * buff, int len)
+{
+    return csum_fold(csum_partial(buff, len, 0));
+}
+
+#endif /* __ASM_AVR32_CHECKSUM_H */