Fixed MTP to work with TWRP

arch/arm/lib/csumpartialcopyuser.S

@@ -0,0 +1,83 @@
+/*
+ *  linux/arch/arm/lib/csumpartialcopyuser.S
+ *
+ *  Copyright (C) 1995-1998 Russell King
+ *
+ * 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.
+ *
+ * 27/03/03 Ian Molton Clean up CONFIG_CPU
+ *
+ */
+#include <linux/linkage.h>
+#include <asm/assembler.h>
+#include <asm/errno.h>
+#include <asm/asm-offsets.h>
+
+		.text
+
+		.macro	save_regs
+		stmfd	sp!, {r1, r2, r4 - r8, lr}
+		.endm
+
+		.macro	load_regs
+		ldmfd	sp!, {r1, r2, r4 - r8, pc}
+		.endm
+
+		.macro	load1b,	reg1
+		ldrusr	\reg1, r0, 1
+		.endm
+
+		.macro	load2b, reg1, reg2
+		ldrusr	\reg1, r0, 1
+		ldrusr	\reg2, r0, 1
+		.endm
+
+		.macro	load1l, reg1
+		ldrusr	\reg1, r0, 4
+		.endm
+
+		.macro	load2l, reg1, reg2
+		ldrusr	\reg1, r0, 4
+		ldrusr	\reg2, r0, 4
+		.endm
+
+		.macro	load4l, reg1, reg2, reg3, reg4
+		ldrusr	\reg1, r0, 4
+		ldrusr	\reg2, r0, 4
+		ldrusr	\reg3, r0, 4
+		ldrusr	\reg4, r0, 4
+		.endm
+
+/*
+ * unsigned int
+ * csum_partial_copy_from_user(const char *src, char *dst, int len, int sum, int *err_ptr)
+ *  r0 = src, r1 = dst, r2 = len, r3 = sum, [sp] = *err_ptr
+ *  Returns : r0 = checksum, [[sp, #0], #0] = 0 or -EFAULT
+ */
+
+#define FN_ENTRY	ENTRY(csum_partial_copy_from_user)
+#define FN_EXIT		ENDPROC(csum_partial_copy_from_user)
+
+#include "csumpartialcopygeneric.S"
+
+/*
+ * FIXME: minor buglet here
+ * We don't return the checksum for the data present in the buffer.  To do
+ * so properly, we would have to add in whatever registers were loaded before
+ * the fault, which, with the current asm above is not predictable.
+ */
+		.pushsection .fixup,"ax"
+		.align	4
+9001:		mov	r4, #-EFAULT
+		ldr	r5, [sp, #8*4]		@ *err_ptr
+		str	r4, [r5]
+		ldmia	sp, {r1, r2}		@ retrieve dst, len
+		add	r2, r2, r1
+		mov	r0, #0			@ zero the buffer
+9002:		teq	r2, r1
+		strneb	r0, [r1], #1
+		bne	9002b
+		load_regs
+		.popsection