From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001
From: André Fabian Silva Delgado <emulatorman@parabola.nu>
Date: Wed, 5 Aug 2015 17:04:01 -0300
Subject: Initial import

---
 arch/avr32/include/asm/checksum.h | 152 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 152 insertions(+)
 create mode 100644 arch/avr32/include/asm/checksum.h

(limited to 'arch/avr32/include/asm/checksum.h')

diff --git a/arch/avr32/include/asm/checksum.h b/arch/avr32/include/asm/checksum.h
new file mode 100644
index 000000000..4ddbfd248
--- /dev/null
+++ b/arch/avr32/include/asm/checksum.h
@@ -0,0 +1,152 @@
+/*
+ * Copyright (C) 2004-2006 Atmel Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#ifndef __ASM_AVR32_CHECKSUM_H
+#define __ASM_AVR32_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
+ */
+__wsum csum_partial(const void *buff, int len, __wsum 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
+ */
+__wsum csum_partial_copy_generic(const void *src, void *dst, int len,
+				       __wsum 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
+ *	access_ok().
+ */
+static inline
+__wsum csum_partial_copy_nocheck(const void *src, void *dst,
+				       int len, __wsum sum)
+{
+	return csum_partial_copy_generic(src, dst, len, sum, NULL, NULL);
+}
+
+static inline
+__wsum csum_partial_copy_from_user(const void __user *src, void *dst,
+					  int len, __wsum sum, int *err_ptr)
+{
+	return csum_partial_copy_generic((const void __force *)src, dst, len,
+					 sum, err_ptr, NULL);
+}
+
+/*
+ *	This is a version of ip_compute_csum() optimized for IP headers,
+ *	which always checksum on 4 octet boundaries.
+ */
+static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
+{
+	unsigned int sum, tmp;
+
+	__asm__ __volatile__(
+		"	ld.w	%0, %1++\n"
+		"	ld.w	%3, %1++\n"
+		"	sub	%2, 4\n"
+		"	add	%0, %3\n"
+		"	ld.w	%3, %1++\n"
+		"	adc	%0, %0, %3\n"
+		"	ld.w	%3, %1++\n"
+		"	adc	%0, %0, %3\n"
+		"	acr	%0\n"
+		"1:	ld.w	%3, %1++\n"
+		"	add	%0, %3\n"
+		"	acr	%0\n"
+		"	sub	%2, 1\n"
+		"	brne	1b\n"
+		"	lsl	%3, %0, 16\n"
+		"	andl	%0, 0\n"
+		"	mov	%2, 0xffff\n"
+		"	add	%0, %3\n"
+		"	adc	%0, %0, %2\n"
+		"	com	%0\n"
+		"	lsr	%0, 16\n"
+		: "=r"(sum), "=r"(iph), "=r"(ihl), "=r"(tmp)
+		: "1"(iph), "2"(ihl)
+		: "memory", "cc");
+	return (__force __sum16)sum;
+}
+
+/*
+ *	Fold a partial checksum
+ */
+
+static inline __sum16 csum_fold(__wsum sum)
+{
+	unsigned int tmp;
+
+	asm("	bfextu	%1, %0, 0, 16\n"
+	    "	lsr	%0, 16\n"
+	    "	add	%0, %1\n"
+	    "	bfextu	%1, %0, 16, 16\n"
+	    "	add	%0, %1"
+	    : "=&r"(sum), "=&r"(tmp)
+	    : "0"(sum));
+
+	return (__force __sum16)~sum;
+}
+
+static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
+					       unsigned short len,
+					       unsigned short proto,
+					       __wsum sum)
+{
+	asm("	add	%0, %1\n"
+	    "	adc	%0, %0, %2\n"
+	    "	adc	%0, %0, %3\n"
+	    "	acr	%0"
+	    : "=r"(sum)
+	    : "r"(daddr), "r"(saddr), "r"(len + proto),
+	      "0"(sum)
+	    : "cc");
+
+	return sum;
+}
+
+/*
+ * computes the checksum of the TCP/UDP pseudo-header
+ * returns a 16-bit checksum, already complemented
+ */
+static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
+						   unsigned short len,
+						   unsigned short proto,
+						   __wsum 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 __sum16 ip_compute_csum(const void *buff, int len)
+{
+    return csum_fold(csum_partial(buff, len, 0));
+}
+
+#endif /* __ASM_AVR32_CHECKSUM_H */
-- 
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