[PATCH v7 10/42] powerpc/32: transfer can avoid saving r4/r5 over trace call

[Nicholas Piggin]

Now that handlers get all registers from pt_regs, r4 and r5 are no
longer live here and may be clobbered.

Signed-off-by: Nicholas Piggin <npiggin at gmail.com>
---
 arch/powerpc/kernel/entry_32.S | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 238eacfda7b0..d6ea3f2d6cc0 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -276,8 +276,7 @@ reenable_mmu:
 	 * We save a bunch of GPRs,
 	 * r3 can be different from GPR3(r1) at this point, r9 and r11
 	 * contains the old MSR and handler address respectively,
-	 * r4 & r5 can contain page fault arguments that need to be passed
-	 * along as well. r0, r6-r8, r12, CCR, CTR, XER etc... are left
+	 * r0, r4-r8, r12, CCR, CTR, XER etc... are left
 	 * clobbered as they aren't useful past this point.
 	 */
 
@@ -285,15 +284,11 @@ reenable_mmu:
 	stw	r9,8(r1)
 	stw	r11,12(r1)
 	stw	r3,16(r1)
-	stw	r4,20(r1)
-	stw	r5,24(r1)
 
 	/* If we are disabling interrupts (normal case), simply log it with
 	 * lockdep
 	 */
 1:	bl	trace_hardirqs_off
-	lwz	r5,24(r1)
-	lwz	r4,20(r1)
 	lwz	r3,16(r1)
 	lwz	r11,12(r1)
 	lwz	r9,8(r1)
-- 
2.23.0