[PATCH] xtensa: Architecture support for Tensilica Xtensa Part 6

The attached patches provides part 6 of an architecture implementation for the
Tensilica Xtensa CPU series.

Signed-off-by: Chris Zankel <chris@zankel.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 264 insertions, 0 deletions

diff --git a/include/asm-xtensa/checksum.h b/include/asm-xtensa/checksum.h
new file mode 100644
index 0000000..1a00fad
--- /dev/null
+++ b/include/asm-xtensa/checksum.h
@@ -0,0 +1,264 @@
+/*
+ * include/asm-xtensa/checksum.h
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2001 - 2005 Tensilica Inc.
+ */
+
+#ifndef _XTENSA_CHECKSUM_H
+#define _XTENSA_CHECKSUM_H
+
+#include <linux/config.h>
+#include <linux/in6.h>
+#include <xtensa/config/core.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
+ */
+asmlinkage unsigned int csum_partial(const unsigned char * buff, int len, unsigned int 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
+ */
+
+asmlinkage unsigned int csum_partial_copy_generic( const char *src, char *dst, int len, int 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().
+ */
+extern __inline__
+unsigned int csum_partial_copy_nocheck ( const char *src, char *dst,
+					int len, int sum)
+{
+	return csum_partial_copy_generic ( src, dst, len, sum, NULL, NULL);
+}
+
+extern __inline__
+unsigned int csum_partial_copy_from_user ( const char *src, char *dst,
+						int len, int sum, int *err_ptr)
+{
+	return csum_partial_copy_generic ( src, dst, len, sum, err_ptr, NULL);
+}
+
+/*
+ * These are the old (and unsafe) way of doing checksums, a warning message will be
+ * printed if they are used and an exeption occurs.
+ *
+ * these functions should go away after some time.
+ */
+
+#define csum_partial_copy_fromuser csum_partial_copy
+unsigned int csum_partial_copy( const char *src, char *dst, int len, int sum);
+
+/*
+ *	Fold a partial checksum
+ */
+
+static __inline__ unsigned int csum_fold(unsigned int sum)
+{
+	unsigned int __dummy;
+	__asm__("extui	%1, %0, 16, 16\n\t"
+		"extui	%0 ,%0, 0, 16\n\t"
+		"add	%0, %0, %1\n\t"
+		"slli	%1, %0, 16\n\t"
+		"add	%0, %0, %1\n\t"
+		"extui	%0, %0, 16, 16\n\t"
+		"neg	%0, %0\n\t"
+		"addi	%0, %0, -1\n\t"
+		"extui	%0, %0, 0, 16\n\t"
+		: "=r" (sum), "=&r" (__dummy)
+		: "0" (sum));
+	return sum;
+}
+
+/*
+ *	This is a version of ip_compute_csum() optimized for IP headers,
+ *	which always checksum on 4 octet boundaries.
+ */
+static __inline__ unsigned short ip_fast_csum(unsigned char * iph, unsigned int ihl)
+{
+	unsigned int sum, tmp, endaddr;
+
+	__asm__ __volatile__(
+		"sub		%0, %0, %0\n\t"
+#if XCHAL_HAVE_LOOPS
+		"loopgtz	%2, 2f\n\t"
+#else
+		"beqz		%2, 2f\n\t"
+		"slli		%4, %2, 2\n\t"
+		"add		%4, %4, %1\n\t"
+		"0:\t"
+#endif
+		"l32i		%3, %1, 0\n\t"
+		"add		%0, %0, %3\n\t"
+		"bgeu		%0, %3, 1f\n\t"
+		"addi		%0, %0, 1\n\t"
+		"1:\t"
+		"addi		%1, %1, 4\n\t"
+#if !XCHAL_HAVE_LOOPS
+		"blt		%1, %4, 0b\n\t"
+#endif
+		"2:\t"
+	/* Since the input registers which are loaded with iph and ihl
+	   are modified, we must also specify them as outputs, or gcc
+	   will assume they contain their original values. */
+		: "=r" (sum), "=r" (iph), "=r" (ihl), "=&r" (tmp), "=&r" (endaddr)
+		: "1" (iph), "2" (ihl));
+
+	return	csum_fold(sum);
+}
+
+static __inline__ unsigned long csum_tcpudp_nofold(unsigned long saddr,
+						   unsigned long daddr,
+						   unsigned short len,
+						   unsigned short proto,
+						   unsigned int sum)
+{
+
+#ifdef __XTENSA_EL__
+	unsigned long len_proto = (ntohs(len)<<16)+proto*256;
+#elif defined(__XTENSA_EB__)
+	unsigned long len_proto = (proto<<16)+len;
+#else
+# error processor byte order undefined!
+#endif
+	__asm__("add	%0, %0, %1\n\t"
+		"bgeu	%0, %1, 1f\n\t"
+		"addi	%0, %0, 1\n\t"
+		"1:\t"
+		"add	%0, %0, %2\n\t"
+		"bgeu	%0, %2, 1f\n\t"
+		"addi	%0, %0, 1\n\t"
+		"1:\t"
+		"add	%0, %0, %3\n\t"
+		"bgeu	%0, %3, 1f\n\t"
+		"addi	%0, %0, 1\n\t"
+		"1:\t"
+		: "=r" (sum), "=r" (len_proto)
+		: "r" (daddr), "r" (saddr), "1" (len_proto), "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 * buff, int len)
+{
+    return csum_fold (csum_partial(buff, len, 0));
+}
+
+#define _HAVE_ARCH_IPV6_CSUM
+static __inline__ unsigned short int csum_ipv6_magic(struct in6_addr *saddr,
+						     struct in6_addr *daddr,
+						     __u32 len,
+						     unsigned short proto,
+						     unsigned int sum)
+{
+	unsigned int __dummy;
+	__asm__("l32i	%1, %2, 0\n\t"
+		"add	%0, %0, %1\n\t"
+		"bgeu	%0, %1, 1f\n\t"
+		"addi	%0, %0, 1\n\t"
+		"1:\t"
+		"l32i	%1, %2, 4\n\t"
+		"add	%0, %0, %1\n\t"
+		"bgeu	%0, %1, 1f\n\t"
+		"addi	%0, %0, 1\n\t"
+		"1:\t"
+		"l32i	%1, %2, 8\n\t"
+		"add	%0, %0, %1\n\t"
+		"bgeu	%0, %1, 1f\n\t"
+		"addi	%0, %0, 1\n\t"
+		"1:\t"
+		"l32i	%1, %2, 12\n\t"
+		"add	%0, %0, %1\n\t"
+		"bgeu	%0, %1, 1f\n\t"
+		"addi	%0, %0, 1\n\t"
+		"1:\t"
+		"l32i	%1, %3, 0\n\t"
+		"add	%0, %0, %1\n\t"
+		"bgeu	%0, %1, 1f\n\t"
+		"addi	%0, %0, 1\n\t"
+		"1:\t"
+		"l32i	%1, %3, 4\n\t"
+		"add	%0, %0, %1\n\t"
+		"bgeu	%0, %1, 1f\n\t"
+		"addi	%0, %0, 1\n\t"
+		"1:\t"
+		"l32i	%1, %3, 8\n\t"
+		"add	%0, %0, %1\n\t"
+		"bgeu	%0, %1, 1f\n\t"
+		"addi	%0, %0, 1\n\t"
+		"1:\t"
+		"l32i	%1, %3, 12\n\t"
+		"add	%0, %0, %1\n\t"
+		"bgeu	%0, %1, 1f\n\t"
+		"addi	%0, %0, 1\n\t"
+		"1:\t"
+		"add	%0, %0, %4\n\t"
+		"bgeu	%0, %4, 1f\n\t"
+		"addi	%0, %0, 1\n\t"
+		"1:\t"
+		"add	%0, %0, %5\n\t"
+		"bgeu	%0, %5, 1f\n\t"
+		"addi	%0, %0, 1\n\t"
+		"1:\t"
+		: "=r" (sum), "=&r" (__dummy)
+		: "r" (saddr), "r" (daddr),
+		  "r" (htonl(len)), "r" (htonl(proto)), "0" (sum));
+
+	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)
+{
+	if (access_ok(VERIFY_WRITE, dst, len))
+		return csum_partial_copy_generic(src, dst, len, sum, NULL, err_ptr);
+
+	if (len)
+		*err_ptr = -EFAULT;
+
+	return -1; /* invalid checksum */
+}
+#endif