--- /dev/null
+/*
+ * 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
+ */
+__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
+ */
+__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
+ * verify_area().
+ */
+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)
+{
+ return csum_partial_copy_generic((const void __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 __sum16 ip_fast_csum(const void *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 (__force __sum16)sum;
+}
+
+/*
+ * Fold a partial checksum
+ */
+
+static inline __sum16 csum_fold(__wsum 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 (__force __sum16)~sum;
+}
+
+static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
+ unsigned short len,
+ unsigned short proto,
+ __wsum 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"(len + proto),
+ "0"(sum)
+ : "cc");
+
+ 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));
+}
+
+#endif /* __ASM_AVR32_CHECKSUM_H */
git://git.onelab.eu / linux-2.6.git / blobdiff