From: Russell King <rmk+ker...@armlinux.org.uk>

Improve the hyp-stub ABI to allow it to do more than just get/set the
vectors.  We follow the example in ARM64, where r0 is used as an opcode
with the other registers as an argument.

Signed-off-by: Russell King <rmk+ker...@armlinux.org.uk>
Signed-off-by: Marc Zyngier <marc.zyng...@arm.com>
---
 arch/arm/kernel/hyp-stub.S | 27 ++++++++++++++++++++++-----
 1 file changed, 22 insertions(+), 5 deletions(-)

diff --git a/arch/arm/kernel/hyp-stub.S b/arch/arm/kernel/hyp-stub.S
index 15d073ae5da2..f3e9ba5fb642 100644
--- a/arch/arm/kernel/hyp-stub.S
+++ b/arch/arm/kernel/hyp-stub.S
@@ -22,6 +22,9 @@
 #include <asm/assembler.h>
 #include <asm/virt.h>
 
+#define HVC_GET_VECTORS 0
+#define HVC_SET_VECTORS 1
+
 #ifndef ZIMAGE
 /*
  * For the kernel proper, we need to find out the CPU boot mode long after
@@ -202,9 +205,19 @@ ARM_BE8(orr        r7, r7, #(1 << 25))     @ HSCTLR.EE
 ENDPROC(__hyp_stub_install_secondary)
 
 __hyp_stub_do_trap:
-       cmp     r0, #-1
-       mrceq   p15, 4, r0, c12, c0, 0  @ get HVBAR
-       mcrne   p15, 4, r0, c12, c0, 0  @ set HVBAR
+       teq     r0, #HVC_GET_VECTORS
+       bne     1f
+       mrc     p15, 4, r0, c12, c0, 0  @ get HVBAR
+       b       __hyp_stub_exit
+
+1:     teq     r0, #HVC_SET_VECTORS
+       bne     1f
+       mcr     p15, 4, r1, c12, c0, 0  @ set HVBAR
+       b       __hyp_stub_exit
+
+1:     mov     r0, #-1
+
+__hyp_stub_exit:
        __ERET
 ENDPROC(__hyp_stub_do_trap)
 
@@ -231,10 +244,14 @@ ENDPROC(__hyp_stub_do_trap)
  * initialisation entry point.
  */
 ENTRY(__hyp_get_vectors)
-       mov     r0, #-1
+       mov     r0, #HVC_GET_VECTORS
+       __HVC(0)
+       ret     lr
 ENDPROC(__hyp_get_vectors)
-       @ fall through
+
 ENTRY(__hyp_set_vectors)
+       mov     r1, r0
+       mov     r0, #HVC_SET_VECTORS
        __HVC(0)
        ret     lr
 ENDPROC(__hyp_set_vectors)
-- 
2.11.0

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