microblaze: Clear i/dcache for sw breakpoints

There is necessary to flush dcache and invalidate
icache for address where breakpoint (brki r16, 0x18)
was. The reason is that for some cases icache line
still keeps brki instruction and it is not updated
by origin instruction maintains by gdbserver.
Signed-off-by: Michal Simek <monstr@monstr.eu>

arch/microblaze/kernel/exceptions.c

@@ -25,6 +25,7 @@
 #include <linux/errno.h>
 #include <linux/ptrace.h>
 #include <asm/current.h>
+#include <asm/cacheflush.h>
 
 #define MICROBLAZE_ILL_OPCODE_EXCEPTION	0x02
 #define MICROBLAZE_IBUS_EXCEPTION	0x03
@@ -52,6 +53,8 @@ void die(const char *str, struct pt_regs *fp, long err)
 void sw_exception(struct pt_regs *regs)
 {
 	_exception(SIGTRAP, regs, TRAP_BRKPT, regs->r16);
+	flush_dcache_range(regs->r16, regs->r16 + 0x4);
+	flush_icache_range(regs->r16, regs->r16 + 0x4);
 }
 
 void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr)