patch-2.4.22 linux-2.4.22/arch/sh64/lib/c-checksum.c

• Lines: 331
• Date: 2003-08-25 04:44:40.000000000 -0700
• Orig file: linux-2.4.21/arch/sh64/lib/c-checksum.c
• Orig date: 1969-12-31 16:00:00.000000000 -0800

diff -urN linux-2.4.21/arch/sh64/lib/c-checksum.c linux-2.4.22/arch/sh64/lib/c-checksum.c
@@ -0,0 +1,330 @@
+/*
+ * arch/sh/lib/csum_parial.c
+ *
+ * This file contains network checksum routines that are better done
+ * in an architecture-specific manner due to speed..
+ */
+
+#include <linux/config.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <asm/byteorder.h>
+#include <asm/uaccess.h>
+
+#if 1
+#define dprintk(x...)
+#else
+#define dprintk(x...) printk(x)
+#endif
+
+static inline unsigned short from64to16(unsigned long long x)
+{
+	/* add up 32-bit words for 33 bits */
+	x = (x & 0xffffffff) + (x >> 32);
+	/* add up 16-bit and 17-bit words for 17+c bits */
+	x = (x & 0xffff) + (x >> 16);
+	/* add up 16-bit and 2-bit for 16+c bit */
+	x = (x & 0xffff) + (x >> 16);
+	/* add up carry.. */
+	x = (x & 0xffff) + (x >> 16);
+	return x;
+}
+
+static inline unsigned short foldto16(unsigned long x)
+{
+	/* add up 16-bit for 17 bits */
+	x = (x & 0xffff) + (x >> 16);
+	/* add up carry.. */
+	x = (x & 0xffff) + (x >> 16);
+	return x;
+}
+
+static inline unsigned short myfoldto16(unsigned long long x)
+{
+	/* Fold down to 32-bits so we don't loose in the typedef-less 
+	   network stack.  */
+	/* 64 to 33 */
+	x = (x & 0xffffffff) + (x >> 32);
+	/* 33 to 32 */
+	x = (x & 0xffffffff) + (x >> 32);
+
+	/* add up 16-bit for 17 bits */
+	x = (x & 0xffff) + (x >> 16);
+	/* add up carry.. */
+	x = (x & 0xffff) + (x >> 16);
+	return x;
+}
+
+#define odd(x) ((x)&1)
+/*
+typedef unsigned short u16;
+typedef unsigned  u32;
+*/
+#define U16(x) ntohs(x)
+
+static unsigned long do_moronic_csum(const unsigned char *a16p, int cnt)
+{
+	u32 sum;
+	int oddb;
+
+	/* This algorithm is correct only for those values of cnt < 65536 */
+
+	oddb = odd(cnt);
+	cnt >>= 1;		/* convert to a word count */
+	sum = 0;		/* do a straight two's complement sum */
+	while (cnt--)
+		sum += U16(*a16p++);
+	if (oddb)		/* pick up the odd byte */
+		sum += U16(*a16p++) & (u16) 0xFF00;
+	/* add in the sum of the `carry' bits, making this one's complement */
+	sum = (sum & (u32) 0xFFFF) + ((sum >> 16) & (u32) 0xFFFF);
+	if (sum & (u32) 0x10000)	/* one last possible carry */
+		sum = (sum + 1) & (u32) 0xFFFF;
+	if (sum == (u32) 0xFFFF)	/* remove the -0 ambiguity */
+		sum = (u32) 0;
+	return sum;
+
+}
+
+#if 0
+static inline unsigned long do_csum(const unsigned char *buff, int len)
+{
+	int odd, count;
+	unsigned long long result = 0;
+
+	if (len <= 0)
+		goto out;
+	odd = 1 & (unsigned long) buff;
+	if (odd) {
+		result = *buff << 8;
+		len--;
+		buff++;
+	}
+	count = len >> 1;	/* nr of 16-bit words.. */
+	if (count) {
+		if (2 & (unsigned long) buff) {
+			result += *(unsigned short *) buff;
+			count--;
+			len -= 2;
+			buff += 2;
+		}
+		count >>= 1;	/* nr of 32-bit words.. */
+		if (count) {
+			if (4 & (unsigned long) buff) {
+				result += *(unsigned int *) buff;
+				count--;
+				len -= 4;
+				buff += 4;
+			}
+			count >>= 1;	/* nr of 64-bit words.. */
+			if (count) {
+				unsigned long carry = 0;
+				do {
+					unsigned long w =
+					    *(unsigned long *) buff;
+					count--;
+					buff += 8;
+					result += carry;
+					result += w;
+					carry = (w > result);
+				} while (count);
+				result += carry;
+				result = (result & 0xffffffff) + (result >> 32);
+			}
+			if (len & 4) {
+				result += *(unsigned int *) buff;
+				buff += 4;
+			}
+		}
+		if (len & 2) {
+			result += *(unsigned short *) buff;
+			buff += 2;
+		}
+	}
+	if (len & 1)
+		result += *buff;
+	result = from64to16(result);
+	if (odd)
+		result = ((result >> 8) & 0xff) | ((result & 0xff) << 8);
+      out:
+	return result;
+}
+
+#else
+
+static unsigned long do_csum(const unsigned char *buff, int len)
+{
+	int odd, count;
+	unsigned long result = 0;
+
+	dprintk("do_csum buff %p, len %d (0x%x)\n", buff, len, len);
+#ifdef DEBUG
+	for (i = 0; i < len; i++) {
+		if ((i % 26) == 0)
+			printk("\n");
+		printk("%02X ", buff[i]);
+	}
+#endif
+
+	if (len <= 0)
+		goto out;
+
+	odd = 1 & (unsigned long) buff;
+	if (odd) {
+		result = *buff << 8;
+		len--;
+		buff++;
+	}
+	count = len >> 1;	/* nr of 16-bit words.. */
+	if (count) {
+		if (2 & (unsigned long) buff) {
+			result += *(unsigned short *) buff;
+			count--;
+			len -= 2;
+			buff += 2;
+		}
+		count >>= 1;	/* nr of 32-bit words.. */
+		if (count) {
+			unsigned long carry = 0;
+			do {
+				unsigned long w = *(unsigned long *) buff;
+				buff += 4;
+				count--;
+				result += carry;
+				result += w;
+				carry = (w > result);
+			} while (count);
+			result += carry;
+			result = (result & 0xffff) + (result >> 16);
+		}
+		if (len & 2) {
+			result += *(unsigned short *) buff;
+			buff += 2;
+		}
+	}
+	if (len & 1)
+		result += *buff;
+	result = foldto16(result);
+	if (odd)
+		result = ((result >> 8) & 0xff) | ((result & 0xff) << 8);
+
+	dprintk("\nCHECKSUM is 0x%x\n", result);
+
+      out:
+	return result;
+}
+
+#endif
+
+/* computes the checksum of a memory block at buff, length len,
+   and adds in "sum" (32-bit)  */
+unsigned int csum_partial(const unsigned char *buff, int len, unsigned int sum)
+{
+	unsigned long long result = do_csum(buff, len);
+
+	/* add in old sum, and carry.. */
+	result += sum;
+	/* 32+c bits -> 32 bits */
+	result = (result & 0xffffffff) + (result >> 32);
+
+	dprintk("csum_partial, buff %p len %d sum 0x%x result=0x%016Lx\n",
+		buff, len, sum, result);
+
+	return result;
+}
+
+/* Copy while checksumming, otherwise like csum_partial.  */
+unsigned int
+csum_partial_copy(const char *src, char *dst, int len, unsigned int sum)
+{
+	sum = csum_partial(src, len, sum);
+	memcpy(dst, src, len);
+
+	return sum;
+}
+
+/* Copy from userspace and compute checksum.  If we catch an exception
+   then zero the rest of the buffer.  */
+unsigned int
+csum_partial_copy_from_user(const char *src, char *dst, int len,
+			    unsigned int sum, int *err_ptr)
+{
+	int missing;
+
+	dprintk
+	    ("csum_partial_copy_from_user src %p, dest %p, len %d, sum %08x, err_ptr %p\n",
+	     src, dst, len, sum, err_ptr);
+	missing = copy_from_user(dst, src, len);
+	dprintk("  access_ok %d\n", __access_ok((unsigned long) src, len));
+	dprintk("  missing %d\n", missing);
+	if (missing) {
+		memset(dst + len - missing, 0, missing);
+		*err_ptr = -EFAULT;
+	}
+
+	return csum_partial(dst, len, sum);
+}
+
+/* Copy to userspace and compute checksum.  */
+unsigned int
+csum_partial_copy_to_user(const char *src, char *dst, int len,
+			  unsigned int sum, int *err_ptr)
+{
+	sum = csum_partial(src, len, sum);
+
+	if (copy_to_user(dst, src, len))
+		*err_ptr = -EFAULT;
+
+	return sum;
+}
+
+/*
+ *	This is a version of ip_compute_csum() optimized for IP headers,
+ *	which always checksum on 4 octet boundaries.
+ */
+unsigned short ip_fast_csum(unsigned char *iph, unsigned int ihl)
+{
+	dprintk("ip_fast_csum %p,%d\n", iph, ihl);
+
+	return ~do_csum(iph, ihl * 4);
+}
+
+unsigned int csum_tcpudp_nofold(unsigned long saddr,
+				unsigned long daddr,
+				unsigned short len,
+				unsigned short proto, unsigned int sum)
+{
+	unsigned long long result;
+
+	dprintk("ntohs(0x%x)=0x%x\n", 0xdead, ntohs(0xdead));
+	dprintk("htons(0x%x)=0x%x\n", 0xdead, htons(0xdead));
+
+	result = ((unsigned long long) saddr +
+		  (unsigned long long) daddr +
+		  (unsigned long long) sum +
+		  ((unsigned long long) ntohs(len) << 16) +
+		  ((unsigned long long) proto << 8));
+
+	/* Fold down to 32-bits so we don't loose in the typedef-less 
+	   network stack.  */
+	/* 64 to 33 */
+	result = (result & 0xffffffff) + (result >> 32);
+	/* 33 to 32 */
+	result = (result & 0xffffffff) + (result >> 32);
+
+	dprintk("%s saddr %x daddr %x len %x proto %x sum %x result %08Lx\n",
+		__FUNCTION__, saddr, daddr, len, proto, sum, result);
+
+	return result;
+}
+
+// Post SIM:
+unsigned int
+csum_partial_copy_nocheck(const char *src, char *dst, int len, unsigned int sum)
+{
+	//  unsigned dummy;
+	dprintk("csum_partial_copy_nocheck src %p dst %p len %d\n", src, dst,
+		len);
+
+	return csum_partial_copy(src, dst, len, sum);
+}