Fixed MTP to work with TWRP

arch/m32r/kernel/sys_m32r.c

@@ -0,0 +1,90 @@
+/*
+ * linux/arch/m32r/kernel/sys_m32r.c
+ *
+ * This file contains various random system calls that
+ * have a non-standard calling sequence on the Linux/M32R platform.
+ *
+ * Taken from i386 version.
+ */
+
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/fs.h>
+#include <linux/smp.h>
+#include <linux/sem.h>
+#include <linux/msg.h>
+#include <linux/shm.h>
+#include <linux/stat.h>
+#include <linux/syscalls.h>
+#include <linux/mman.h>
+#include <linux/file.h>
+#include <linux/utsname.h>
+#include <linux/ipc.h>
+
+#include <asm/uaccess.h>
+#include <asm/cachectl.h>
+#include <asm/cacheflush.h>
+#include <asm/syscall.h>
+#include <asm/unistd.h>
+
+/*
+ * sys_tas() - test-and-set
+ */
+asmlinkage int sys_tas(int __user *addr)
+{
+	int oldval;
+
+	if (!access_ok(VERIFY_WRITE, addr, sizeof (int)))
+		return -EFAULT;
+
+	/* atomic operation:
+	 *   oldval = *addr; *addr = 1;
+	 */
+	__asm__ __volatile__ (
+		DCACHE_CLEAR("%0", "r4", "%1")
+		"	.fillinsn\n"
+		"1:\n"
+		"	lock	%0, @%1	    ->	unlock	%2, @%1\n"
+		"2:\n"
+		/* NOTE:
+		 *   The m32r processor can accept interrupts only
+		 *   at the 32-bit instruction boundary.
+		 *   So, in the above code, the "unlock" instruction
+		 *   can be executed continuously after the "lock"
+		 *   instruction execution without any interruptions.
+		 */
+		".section .fixup,\"ax\"\n"
+		"	.balign 4\n"
+		"3:	ldi	%0, #%3\n"
+		"	seth	r14, #high(2b)\n"
+		"	or3	r14, r14, #low(2b)\n"
+		"	jmp	r14\n"
+		".previous\n"
+		".section __ex_table,\"a\"\n"
+		"	.balign 4\n"
+		"	.long 1b,3b\n"
+		".previous\n"
+		: "=&r" (oldval)
+		: "r" (addr), "r" (1), "i"(-EFAULT)
+		: "r14", "memory"
+#ifdef CONFIG_CHIP_M32700_TS1
+		  , "r4"
+#endif /* CONFIG_CHIP_M32700_TS1 */
+	);
+
+	return oldval;
+}
+
+asmlinkage int sys_cacheflush(void *addr, int bytes, int cache)
+{
+	/* This should flush more selectively ...  */
+	_flush_cache_all();
+	return 0;
+}
+
+asmlinkage int sys_cachectl(char *addr, int nbytes, int op)
+{
+	/* Not implemented yet. */
+	return -ENOSYS;
+}