blackfin architecture

This adds support for the Analog Devices Blackfin processor architecture, and
currently supports the BF533, BF532, BF531, BF537, BF536, BF534, and BF561
(Dual Core) devices, with a variety of development platforms including those
avaliable from Analog Devices (BF533-EZKit, BF533-STAMP, BF537-STAMP,
BF561-EZKIT), and Bluetechnix!  Tinyboards.

The Blackfin architecture was jointly developed by Intel and Analog Devices
Inc.  (ADI) as the Micro Signal Architecture (MSA) core and introduced it in
December of 2000.  Since then ADI has put this core into its Blackfin
processor family of devices.  The Blackfin core has the advantages of a clean,
orthogonal,RISC-like microprocessor instruction set.  It combines a dual-MAC
(Multiply/Accumulate), state-of-the-art signal processing engine and
single-instruction, multiple-data (SIMD) multimedia capabilities into a single
instruction-set architecture.

The Blackfin architecture, including the instruction set, is described by the
ADSP-BF53x/BF56x Blackfin Processor Programming Reference
http://blackfin.uclinux.org/gf/download/frsrelease/29/2549/Blackfin_PRM.pdf

The Blackfin processor is already supported by major releases of gcc, and
there are binary and source rpms/tarballs for many architectures at:
http://blackfin.uclinux.org/gf/project/toolchain/frs There is complete
documentation, including "getting started" guides available at:
http://docs.blackfin.uclinux.org/ which provides links to the sources and
patches you will need in order to set up a cross-compiling environment for
bfin-linux-uclibc

This patch, as well as the other patches (toolchain, distribution,
uClibc) are actively supported by Analog Devices Inc, at:
http://blackfin.uclinux.org/

We have tested this on LTP, and our test plan (including pass/fails) can
be found at:
http://docs.blackfin.uclinux.org/doku.php?id=testing_the_linux_kernel

[m.kozlowski@tuxland.pl: balance parenthesis in blackfin header files]
Signed-off-by: Bryan Wu <bryan.wu@analog.com>
Signed-off-by: Mariusz Kozlowski <m.kozlowski@tuxland.pl>
Signed-off-by: Aubrey Li <aubrey.li@analog.com>
Signed-off-by: Jie Zhang <jie.zhang@analog.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 140 insertions, 0 deletions

diff --git a/arch/blackfin/lib/checksum.c b/arch/blackfin/lib/checksum.c
new file mode 100644
index 000000000000..42768e0c80ca
--- /dev/null
+++ b/arch/blackfin/lib/checksum.c
@@ -0,0 +1,140 @@
+/*
+ * File:         arch/blackfin/lib/checksum.c
+ * Based on:     none - original work
+ * Author:
+ *
+ * Created:
+ * Description:  An implementation of the TCP/IP protocol suite for the LINUX
+ *               operating system.  INET is implemented using the  BSD Socket
+ *               interface as the means of communication with the user level.
+ *
+ * Modified:
+ *               Copyright 2004-2006 Analog Devices Inc.
+ *
+ * Bugs:         Enter bugs at http://blackfin.uclinux.org/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see the file COPYING, or write
+ * to the Free Software Foundation, Inc.,
+ * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#include <net/checksum.h>
+#include <asm/checksum.h>
+
+#ifdef CONFIG_IP_CHECKSUM_L1
+static unsigned short do_csum(const unsigned char *buff, int len)__attribute__((l1_text));
+#endif
+
+static unsigned short do_csum(const unsigned char *buff, int len)
+{
+	register unsigned long sum = 0;
+	int swappem = 0;
+
+	if (1 & (unsigned long)buff) {
+		sum = *buff << 8;
+		buff++;
+		len--;
+		++swappem;
+	}
+
+	while (len > 1) {
+		sum += *(unsigned short *)buff;
+		buff += 2;
+		len -= 2;
+	}
+
+	if (len > 0)
+		sum += *buff;
+
+	/*  Fold 32-bit sum to 16 bits */
+	while (sum >> 16)
+		sum = (sum & 0xffff) + (sum >> 16);
+
+	if (swappem)
+		sum = ((sum & 0xff00) >> 8) + ((sum & 0x00ff) << 8);
+
+	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)
+{
+	return ~do_csum(iph, ihl * 4);
+}
+
+/*
+ * 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)
+{
+	/*
+	 * Just in case we get nasty checksum data...
+	 * Like 0xffff6ec3 in the case of our IPv6 multicast header.
+	 * We fold to begin with, as well as at the end.
+	 */
+	sum = (sum & 0xffff) + (sum >> 16);
+
+	sum += do_csum(buff, len);
+
+	sum = (sum & 0xffff) + (sum >> 16);
+
+	return sum;
+}
+
+/*
+ * this routine is used for miscellaneous IP-like checksums, mainly
+ * in icmp.c
+ */
+unsigned short ip_compute_csum(const unsigned char *buff, int len)
+{
+	return ~do_csum(buff, len);
+}
+
+/*
+ * copy from fs while checksumming, otherwise like csum_partial
+ */
+
+unsigned int
+csum_partial_copy_from_user(const unsigned char *src, unsigned char *dst,
+			    int len, int sum, int *csum_err)
+{
+	if (csum_err)
+		*csum_err = 0;
+	memcpy(dst, src, len);
+	return csum_partial(dst, len, sum);
+}
+
+/*
+ * copy from ds while checksumming, otherwise like csum_partial
+ */
+
+unsigned int csum_partial_copy(const unsigned char *src, unsigned char *dst,
+			       int len, int sum)
+{
+	memcpy(dst, src, len);
+	return csum_partial(dst, len, sum);
+}