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/entry-common.S b/arch/sh/kernel/entry-common.S
index 397ac71d97f1..926b2e7b11c1 100644
--- a/arch/sh/kernel/entry-common.S
+++ b/arch/sh/kernel/entry-common.S
@@ -176,25 +176,6 @@ work_notifysig:
         jmp     @r1
          lds    r0, pr
 work_resched:
-#if defined(CONFIG_GUSA) && !defined(CONFIG_PREEMPT)
-        ! gUSA handling
-        mov.l   @(OFF_SP,r15), r0       ! get user space stack pointer
-        mov     r0, r1
-        shll    r0
-        bf/s    1f
-         shll   r0
-        bf/s    1f
-         mov    #OFF_PC, r0
-        !                                 SP >= 0xc0000000 : gUSA mark
-        mov.l   @(r0,r15), r2           ! get user space PC (program counter)
-        mov.l   @(OFF_R0,r15), r3       ! end point
-        cmp/hs  r3, r2                  ! r2 >= r3? 
-        bt      1f
-        add     r3, r1                  ! rewind point #2
-        mov.l   r1, @(r0,r15)           ! reset PC to rewind point #2
-        !
-1:
-#endif
         mov.l   1f, r1
         jsr     @r1                             ! schedule
          nop