[PULL,37/79] arm64: KVM: Move lr save/restore to do_el2_call

Commit Message

Christoffer Dall April 23, 2017, 5:08 p.m. UTC

From: Marc Zyngier <[e-mail]>

At the moment, we only save/restore lr if on VHE, as we rely only
the EL1 code to have preserved it in the non-VHE case.

As we're about to get rid of the latter, let's move the save/restore
code to the do_el2_call macro, unifying both code paths.

Acked-by: Catalin Marinas <[e-mail]>
Signed-off-by: Marc Zyngier <[e-mail]>
Signed-off-by: Christoffer Dall <[e-mail]>
---
 arch/arm64/kvm/hyp.S           | 3 ---
 arch/arm64/kvm/hyp/hyp-entry.S | 4 ++--
 2 files changed, 2 insertions(+), 5 deletions(-)

Patch

diff --git a/arch/arm64/kvm/hyp.S b/arch/arm64/kvm/hyp.S
index 2726635..f6f20b5 100644
--- a/arch/arm64/kvm/hyp.S
+++ b/arch/arm64/kvm/hyp.S
@@ -38,13 +38,10 @@ 
  * A function pointer with a value less than 0xfff has a special meaning,
  * and is used to implement __hyp_get_vectors in the same way as in
  * arch/arm64/kernel/hyp_stub.S.
- * HVC behaves as a 'bl' call and will clobber lr.
  */
 ENTRY(__kvm_call_hyp)
 alternative_if_not ARM64_HAS_VIRT_HOST_EXTN
-	str     lr, [sp, #-16]!
 	hvc	#0
-	ldr     lr, [sp], #16
 	ret
 alternative_else_nop_endif
 	b	__vhe_hyp_call
diff --git a/arch/arm64/kvm/hyp/hyp-entry.S b/arch/arm64/kvm/hyp/hyp-entry.S
index 5e9052f..d8ef788 100644
--- a/arch/arm64/kvm/hyp/hyp-entry.S
+++ b/arch/arm64/kvm/hyp/hyp-entry.S
@@ -32,17 +32,17 @@ 
 	 * Shuffle the parameters before calling the function
 	 * pointed to in x0. Assumes parameters in x[1,2,3].
 	 */
+	str	lr, [sp, #-16]!
 	mov	lr, x0
 	mov	x0, x1
 	mov	x1, x2
 	mov	x2, x3
 	blr	lr
+	ldr	lr, [sp], #16
 .endm
 
 ENTRY(__vhe_hyp_call)
-	str	lr, [sp, #-16]!
 	do_el2_call
-	ldr	lr, [sp], #16
 	/*
 	 * We used to rely on having an exception return to get
 	 * an implicit isb. In the E2H case, we don't have it anymore.