sh: Tidy up NEFF-based sign extension for SH-5.

This consolidates all of the NEFF-based sign extension for SH-5.
In the future the other SH code will need to make use of this as well,
so make it generic in preparation for more 32/64 consolidation.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 10 insertions, 14 deletions

diff --git a/arch/sh/kernel/process_64.c b/arch/sh/kernel/process_64.c
index 24de742..1192398 100644
--- a/arch/sh/kernel/process_64.c
+++ b/arch/sh/kernel/process_64.c
@@ -425,7 +425,6 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
 		struct task_struct *p, struct pt_regs *regs)
 {
 	struct pt_regs *childregs;
-	unsigned long long se;			/* Sign extension */
 
 #ifdef CONFIG_SH_FPU
 	if(last_task_used_math == current) {
@@ -441,11 +440,19 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
 
 	*childregs = *regs;
 
+	/*
+	 * Sign extend the edited stack.
+	 * Note that thread.pc and thread.pc will stay
+	 * 32-bit wide and context switch must take care
+	 * of NEFF sign extension.
+	 */
 	if (user_mode(regs)) {
-		childregs->regs[15] = usp;
+		childregs->regs[15] = neff_sign_extend(usp);
 		p->thread.uregs = childregs;
 	} else {
-		childregs->regs[15] = (unsigned long)task_stack_page(p) + THREAD_SIZE;
+		childregs->regs[15] =
+			neff_sign_extend((unsigned long)task_stack_page(p) +
+					 THREAD_SIZE);
 	}
 
 	childregs->regs[9] = 0; /* Set return value for child */
@@ -454,17 +461,6 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
 	p->thread.sp = (unsigned long) childregs;
 	p->thread.pc = (unsigned long) ret_from_fork;
 
-	/*
-	 * Sign extend the edited stack.
-         * Note that thread.pc and thread.pc will stay
-	 * 32-bit wide and context switch must take care
-	 * of NEFF sign extension.
-	 */
-
-	se = childregs->regs[15];
-	se = (se & NEFF_SIGN) ? (se | NEFF_MASK) : se;
-	childregs->regs[15] = se;
-
 	return 0;
 }