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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/sh64/lib/c-checksum.c
downloadlinux-linaro-stable-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'arch/sh64/lib/c-checksum.c')
-rw-r--r--arch/sh64/lib/c-checksum.c231
1 files changed, 231 insertions, 0 deletions
diff --git a/arch/sh64/lib/c-checksum.c b/arch/sh64/lib/c-checksum.c
new file mode 100644
index 000000000000..a82d8f1a7a64
--- /dev/null
+++ b/arch/sh64/lib/c-checksum.c
@@ -0,0 +1,231 @@
+/*
+ * arch/sh/lib/csum_parial.c
+ *
+ * This file contains network checksum routines that are better done
+ * in an architecture-specific manner due to speed..
+ */
+
+#undef DEBUG
+
+#include <linux/config.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <asm/byteorder.h>
+#include <asm/uaccess.h>
+
+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)
+#define U16(x) ntohs(x)
+
+static unsigned long do_csum(const unsigned char *buff, int len)
+{
+ int odd, count;
+ unsigned long result = 0;
+
+ pr_debug("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);
+
+ pr_debug("\nCHECKSUM is 0x%x\n", result);
+
+ out:
+ return result;
+}
+
+/* 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);
+
+ pr_debug("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 unsigned char *src, unsigned 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 unsigned char *src, unsigned char *dst, int len,
+ unsigned int sum, int *err_ptr)
+{
+ int missing;
+
+ pr_debug
+ ("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);
+ pr_debug(" access_ok %d\n", __access_ok((unsigned long) src, len));
+ pr_debug(" 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 unsigned char *src, unsigned 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)
+{
+ pr_debug("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;
+
+ pr_debug("ntohs(0x%x)=0x%x\n", 0xdead, ntohs(0xdead));
+ pr_debug("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);
+
+ pr_debug("%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 unsigned char *src, unsigned char *dst, int len, unsigned int sum)
+{
+ // unsigned dummy;
+ pr_debug("csum_partial_copy_nocheck src %p dst %p len %d\n", src, dst,
+ len);
+
+ return csum_partial_copy(src, dst, len, sum);
+}