Fixed MTP to work with TWRP

arch/x86/include/asm/checksum_64.h

@@ -0,0 +1,198 @@
+#ifndef _ASM_X86_CHECKSUM_64_H
+#define _ASM_X86_CHECKSUM_64_H
+
+/*
+ * Checksums for x86-64
+ * Copyright 2002 by Andi Kleen, SuSE Labs
+ * with some code from asm-x86/checksum.h
+ */
+
+#include <linux/compiler.h>
+#include <asm/uaccess.h>
+#include <asm/byteorder.h>
+
+/**
+ * csum_fold - Fold and invert a 32bit checksum.
+ * sum: 32bit unfolded sum
+ *
+ * Fold a 32bit running checksum to 16bit and invert it. This is usually
+ * the last step before putting a checksum into a packet.
+ * Make sure not to mix with 64bit checksums.
+ */
+static inline __sum16 csum_fold(__wsum sum)
+{
+	asm("  addl %1,%0\n"
+	    "  adcl $0xffff,%0"
+	    : "=r" (sum)
+	    : "r" ((__force u32)sum << 16),
+	      "0" ((__force u32)sum & 0xffff0000));
+	return (__force __sum16)(~(__force u32)sum >> 16);
+}
+
+/*
+ *	This is a version of ip_compute_csum() optimized for IP headers,
+ *	which always checksum on 4 octet boundaries.
+ *
+ *	By Jorge Cwik <jorge@laser.satlink.net>, adapted for linux by
+ *	Arnt Gulbrandsen.
+ */
+
+/**
+ * ip_fast_csum - Compute the IPv4 header checksum efficiently.
+ * iph: ipv4 header
+ * ihl: length of header / 4
+ */
+static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
+{
+	unsigned int sum;
+
+	asm("  movl (%1), %0\n"
+	    "  subl $4, %2\n"
+	    "  jbe 2f\n"
+	    "  addl 4(%1), %0\n"
+	    "  adcl 8(%1), %0\n"
+	    "  adcl 12(%1), %0\n"
+	    "1: adcl 16(%1), %0\n"
+	    "  lea 4(%1), %1\n"
+	    "  decl %2\n"
+	    "  jne	1b\n"
+	    "  adcl $0, %0\n"
+	    "  movl %0, %2\n"
+	    "  shrl $16, %0\n"
+	    "  addw %w2, %w0\n"
+	    "  adcl $0, %0\n"
+	    "  notl %0\n"
+	    "2:"
+	/* 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)
+	    : "1" (iph), "2" (ihl)
+	    : "memory");
+	return (__force __sum16)sum;
+}
+
+/**
+ * csum_tcpup_nofold - Compute an IPv4 pseudo header checksum.
+ * @saddr: source address
+ * @daddr: destination address
+ * @len: length of packet
+ * @proto: ip protocol of packet
+ * @sum: initial sum to be added in (32bit unfolded)
+ *
+ * Returns the pseudo header checksum the input data. Result is
+ * 32bit unfolded.
+ */
+static inline __wsum
+csum_tcpudp_nofold(__be32 saddr, __be32 daddr, unsigned short len,
+		   unsigned short proto, __wsum sum)
+{
+	asm("  addl %1, %0\n"
+	    "  adcl %2, %0\n"
+	    "  adcl %3, %0\n"
+	    "  adcl $0, %0\n"
+	    : "=r" (sum)
+	    : "g" (daddr), "g" (saddr),
+	      "g" ((len + proto)<<8), "0" (sum));
+	return sum;
+}
+
+
+/**
+ * csum_tcpup_magic - Compute an IPv4 pseudo header checksum.
+ * @saddr: source address
+ * @daddr: destination address
+ * @len: length of packet
+ * @proto: ip protocol of packet
+ * @sum: initial sum to be added in (32bit unfolded)
+ *
+ * Returns the 16bit pseudo header checksum the input data already
+ * complemented and ready to be filled in.
+ */
+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));
+}
+
+/**
+ * csum_partial - Compute an internet checksum.
+ * @buff: buffer to be checksummed
+ * @len: length of buffer.
+ * @sum: initial sum to be added in (32bit unfolded)
+ *
+ * Returns the 32bit unfolded internet checksum of the buffer.
+ * Before filling it in it needs to be csum_fold()'ed.
+ * buff should be aligned to a 64bit boundary if possible.
+ */
+extern __wsum csum_partial(const void *buff, int len, __wsum sum);
+
+#define  _HAVE_ARCH_COPY_AND_CSUM_FROM_USER 1
+#define HAVE_CSUM_COPY_USER 1
+
+
+/* Do not call this directly. Use the wrappers below */
+extern __visible __wsum csum_partial_copy_generic(const void *src, const void *dst,
+					int len, __wsum sum,
+					int *src_err_ptr, int *dst_err_ptr);
+
+
+extern __wsum csum_partial_copy_from_user(const void __user *src, void *dst,
+					  int len, __wsum isum, int *errp);
+extern __wsum csum_partial_copy_to_user(const void *src, void __user *dst,
+					int len, __wsum isum, int *errp);
+extern __wsum csum_partial_copy_nocheck(const void *src, void *dst,
+					int len, __wsum sum);
+
+/* Old names. To be removed. */
+#define csum_and_copy_to_user csum_partial_copy_to_user
+#define csum_and_copy_from_user csum_partial_copy_from_user
+
+/**
+ * ip_compute_csum - Compute an 16bit IP checksum.
+ * @buff: buffer address.
+ * @len: length of buffer.
+ *
+ * Returns the 16bit folded/inverted checksum of the passed buffer.
+ * Ready to fill in.
+ */
+extern __sum16 ip_compute_csum(const void *buff, int len);
+
+/**
+ * csum_ipv6_magic - Compute checksum of an IPv6 pseudo header.
+ * @saddr: source address
+ * @daddr: destination address
+ * @len: length of packet
+ * @proto: protocol of packet
+ * @sum: initial sum (32bit unfolded) to be added in
+ *
+ * Computes an IPv6 pseudo header checksum. This sum is added the checksum
+ * into UDP/TCP packets and contains some link layer information.
+ * Returns the unfolded 32bit checksum.
+ */
+
+struct in6_addr;
+
+#define _HAVE_ARCH_IPV6_CSUM 1
+extern __sum16
+csum_ipv6_magic(const struct in6_addr *saddr, const struct in6_addr *daddr,
+		__u32 len, unsigned short proto, __wsum sum);
+
+static inline unsigned add32_with_carry(unsigned a, unsigned b)
+{
+	asm("addl %2,%0\n\t"
+	    "adcl $0,%0"
+	    : "=r" (a)
+	    : "0" (a), "rm" (b));
+	return a;
+}
+
+#define HAVE_ARCH_CSUM_ADD
+static inline __wsum csum_add(__wsum csum, __wsum addend)
+{
+	return (__force __wsum)add32_with_carry((__force unsigned)csum,
+						(__force unsigned)addend);
+}
+
+#endif /* _ASM_X86_CHECKSUM_64_H */