MIPS: kernel: {ftrace,kgdb}: Set correct address limit for cache flushes

When flushing the icache, make sure the address limit is correct
so the appropriate 'cache' instruction will be used. This has no
impact on cores operating in non-eva mode. However, when EVA is
enabled, we ensure that 'cache' will be used instead of 'cachee'.

Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
diff --git a/arch/mips/kernel/ftrace.c b/arch/mips/kernel/ftrace.c
index 185ba25..ddcc350 100644
--- a/arch/mips/kernel/ftrace.c
+++ b/arch/mips/kernel/ftrace.c
@@ -90,6 +90,7 @@
 static int ftrace_modify_code(unsigned long ip, unsigned int new_code)
 {
 	int faulted;
+	mm_segment_t old_fs;
 
 	/* *(unsigned int *)ip = new_code; */
 	safe_store_code(new_code, ip, faulted);
@@ -97,7 +98,10 @@
 	if (unlikely(faulted))
 		return -EFAULT;
 
+	old_fs = get_fs();
+	set_fs(get_ds());
 	flush_icache_range(ip, ip + 8);
+	set_fs(old_fs);
 
 	return 0;
 }