microblaze: Add STATE_SAVE_ARG_SPACE for noMMU kernel too

For noMMU kernel this change nothing bring but this change
helps with MMU synchronization.

Signed-off-by: Michal Simek <monstr@monstr.eu>

arch/microblaze/include/asm/entry.h

@@ -31,4 +31,7 @@ DECLARE_PER_CPU(unsigned int, R11_SAVE); /* Temp variable for entry */
 DECLARE_PER_CPU(unsigned int, CURRENT_SAVE); /* Saved current pointer */
 # endif /* __ASSEMBLY__ */
 
+/* noMMU hasn't any space for args */
+# define STATE_SAVE_ARG_SPACE	(0)
+
 #endif /* _ASM_MICROBLAZE_ENTRY_H */

arch/microblaze/include/asm/processor.h

@@ -15,6 +15,8 @@
 #include <asm/setup.h>
 #include <asm/registers.h>
 #include <asm/segment.h>
+#include <asm/entry.h>
+#include <asm/current.h>
 
 # ifndef __ASSEMBLY__
 /* from kernel/cpu/mb.c */

arch/microblaze/kernel/signal.c

@@ -178,7 +178,9 @@ restore_sigcontext(struct pt_regs *regs, struct sigcontext *sc, int *rval_p)
 
 asmlinkage int sys_sigreturn(struct pt_regs *regs)
 {
-	struct sigframe *frame = (struct sigframe *)regs->r1;
+	struct sigframe *frame =
+			(struct sigframe *)(regs->r1 + STATE_SAVE_ARG_SPACE);
+
 	sigset_t set;
 	int rval;
 
@@ -209,7 +211,9 @@ badframe:
 
 asmlinkage int sys_rt_sigreturn(struct pt_regs *regs)
 {
-	struct rt_sigframe *frame = (struct rt_sigframe *)regs->r1;
+	struct rt_sigframe *frame =
+			(struct rt_sigframe *)(regs->r1 + STATE_SAVE_ARG_SPACE);
+
 	sigset_t set;
 	stack_t st;
 	int rval;
@@ -336,7 +340,8 @@ static void setup_frame(int sig, struct k_sigaction *ka,
 		goto give_sigsegv;
 
 	/* Set up registers for signal handler */
-	regs->r1 = (unsigned long) frame;
+	regs->r1 = (unsigned long) frame - STATE_SAVE_ARG_SPACE;
+
 	/* Signal handler args: */
 	regs->r5 = signal; /* Arg 0: signum */
 	regs->r6 = (unsigned long) &frame->sc; /* arg 1: sigcontext */
@@ -414,7 +419,8 @@ static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
 		goto give_sigsegv;
 
 	/* Set up registers for signal handler */
-	regs->r1 = (unsigned long) frame;
+	regs->r1 = (unsigned long) frame - STATE_SAVE_ARG_SPACE;
+
 	/* Signal handler args: */
 	regs->r5 = signal; /* arg 0: signum */
 	regs->r6 = (unsigned long) &frame->info; /* arg 1: siginfo */