patch-2.4.0-test12 linux/include/asm-parisc/checksum.h

• Lines: 175
• Date: Tue Dec 5 12:29:39 2000
• Orig file: v2.4.0-test11/linux/include/asm-parisc/checksum.h
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.4.0-test11/linux/include/asm-parisc/checksum.h linux/include/asm-parisc/checksum.h
@@ -0,0 +1,174 @@
+#ifndef _PARISC_CHECKSUM_H
+#define _PARISC_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 unsigned int csum_partial(const unsigned char *, int, unsigned int);
+
+/*
+ * 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 unsigned int csum_partial_copy(const char *, char *, int, unsigned int);
+
+/*
+ * the same as csum_partial, but copies from user space
+ *
+ * this is obsolete and will go away.
+ */
+#define csum_partial_copy_fromuser csum_partial_copy
+
+/*
+ * this is a new version of the above that records errors it finds in *errp,
+ * but continues and zeros the rest of the buffer.
+ */
+unsigned int csum_partial_copy_from_user(const char *src, char *dst, int len, unsigned int sum, int *errp);
+
+/*
+ *	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().
+ */
+extern __inline__
+unsigned int csum_partial_copy_nocheck (const char *src, char *dst,
+					int len, int sum)
+{
+	return csum_partial_copy (src, dst, len, sum);
+}
+
+/*
+ *	Optimized for IP headers, which always checksum on 4 octet boundaries.
+ *
+ *	Written by Randolph Chung <tausq@debian.org>
+ */
+static inline unsigned short ip_fast_csum(unsigned char * iph,
+					  unsigned int ihl) {
+	unsigned int sum;
+
+
+	__asm__ __volatile__ ("
+	ldws,ma		4(%1), %0
+	addi		-4, %2, %2
+	comib,>=	0, %2, 2f
+	
+	ldws,ma		4(%1), %%r19
+	add		%0, %%r19, %0
+	ldws,ma		4(%1), %%r19
+	addc		%0, %%r19, %0
+	ldws,ma		4(%1), %%r19
+	addc		%0, %%r19, %0
+1:	ldws,ma		4(%1), %%r19
+	addib,<>	-1, %2, 1b
+	addc		%0, %%r19, %0
+	addc		%0, %%r0, %0
+
+	zdepi		-1, 31, 16, %%r19
+	and		%0, %%r19, %%r20
+	extru		%0, 15, 16, %%r21
+	add		%%r20, %%r21, %0
+	and		%0, %%r19, %%r20
+	extru		%0, 15, 16, %%r21
+	add		%%r20, %%r21, %0
+	subi		-1, %0, %0
+2:
+	"
+	: "=r" (sum), "=r" (iph), "=r" (ihl)
+	: "1" (iph), "2" (ihl)
+	: "r19", "r20", "r21" );
+
+	return(sum);
+}
+
+/*
+ *	Fold a partial checksum
+ */
+static inline unsigned int csum_fold(unsigned int sum)
+{
+	sum = (sum & 0xffff) + (sum >> 16);
+	sum = (sum & 0xffff) + (sum >> 16);
+	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  %1, %0, %0
+		addc %2, %0, %0
+		addc %3, %0, %0
+		addc %%r0, %0, %0 "
+		: "=r" (sum)
+		: "r" (daddr), "r"(saddr), "r"((proto<<16)+len), "0"(sum));
+    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 * buf, int len) {
+	 return csum_fold (csum_partial(buf, len, 0));
+}
+
+#define _HAVE_ARCH_IPV6_CSUM
+static __inline__ unsigned short int csum_ipv6_magic(struct in6_addr *saddr,
+						     struct in6_addr *daddr,
+						     __u16 len,
+						     unsigned short proto,
+						     unsigned int sum) 
+{
+	BUG();
+	return csum_fold(sum);
+}
+
+/* 
+ *	Copy and checksum to user
+ */
+#define HAVE_CSUM_COPY_USER
+static __inline__ unsigned int csum_and_copy_to_user (const char *src, char *dst,
+				    int len, int sum, int *err_ptr)
+{
+	/* code stolen from include/asm-mips64 */
+	sum = csum_partial(src, len, sum);
+	 
+	if (copy_to_user(dst, src, len)) {
+		*err_ptr = -EFAULT;
+		return -1;
+	}
+
+	return sum;
+}
+
+#endif
+