sh: GUSA atomic rollback support.

This implements kernel-level atomic rollback built on top of gUSA,
as an alternative non-IRQ based atomicity method. This is generally
a faster method for platforms that are lacking the LL/SC pairs that
SH-4A and later use, and is only supportable on legacy cores.

Signed-off-by: Stuart Menefy <stuart.menefy@st.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 0 insertions, 19 deletions

diff --git a/arch/sh/kernel/process_32.c b/arch/sh/kernel/process_32.c
index b48324867eee..9ab1926b9d10 100644
--- a/arch/sh/kernel/process_32.c
+++ b/arch/sh/kernel/process_32.c
@@ -322,25 +322,6 @@ struct task_struct *__switch_to(struct task_struct *prev,
         unlazy_fpu(prev, task_pt_regs(prev));
 #endif
 
-#if defined(CONFIG_GUSA) && defined(CONFIG_PREEMPT)
-        {
-                struct pt_regs *regs;
-
-                preempt_disable();
-                regs = task_pt_regs(prev);
-                if (user_mode(regs) && regs->regs[15] >= 0xc0000000) {
-                        int offset = (int)regs->regs[15];
-
-                        /* Reset stack pointer: clear critical region mark */
-                        regs->regs[15] = regs->regs[1];
-                        if (regs->pc < regs->regs[0])
-                                /* Go to rewind point */
-                                regs->pc = regs->regs[0] + offset;
-                }
-                preempt_enable_no_resched();
-        }
-#endif
-
 #ifdef CONFIG_MMU
         /*
          * Restore the kernel mode register