[Xen-devel] [PATCH RFC for-4.13 09/10] xen/arm: asm: Replace use of ALTERNATIVE with alternative_if

[Julien Grall <julien.grall@xxxxxxx>]

Using alternative_if makes the code a bit more streamlined.

Take the opportunity to use the new auto-nop infrastructure to avoid
counting the number of nop in the else part for arch/arm/arm64/entry.S

Signed-off-by: Julien Grall <julien.grall@xxxxxxx>

---
    This is pretty much a matter of taste, but at least for arm64 this
    allows us to use the auto-nop infrastructure. So the arm32 is more
    to keep inline with arm64.
---
 xen/arch/arm/arm32/entry.S | 9 ++++++---
 xen/arch/arm/arm64/entry.S | 8 +++++---
 2 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/xen/arch/arm/arm32/entry.S b/xen/arch/arm/arm32/entry.S
index 0b4cd19abd..1428cd3583 100644
--- a/xen/arch/arm/arm32/entry.S
+++ b/xen/arch/arm/arm32/entry.S
@@ -65,9 +65,12 @@ save_guest_regs:
          * If the SKIP_SYNCHRONIZE_SERROR_ENTRY_EXIT has been set in the cpu
          * feature, the checking of pending SErrors will be skipped.
          */
-        ALTERNATIVE("nop",
-                    "b skip_check",
-                    SKIP_SYNCHRONIZE_SERROR_ENTRY_EXIT)
+        alternative_if SKIP_SYNCHRONIZE_SERROR_ENTRY_EXIT
+        nop
+        alternative_else
+        b   skip_check
+        alternative_endif
+
         /*
          * Start to check pending virtual abort in the gap of Guest -> HYP
          * world switch.
diff --git a/xen/arch/arm/arm64/entry.S b/xen/arch/arm/arm64/entry.S
index 458d12f188..91cf6ee6f4 100644
--- a/xen/arch/arm/arm64/entry.S
+++ b/xen/arch/arm/arm64/entry.S
@@ -170,9 +170,11 @@
          * is not set. If a vSError took place, the initial exception will be
          * skipped. Exit ASAP
          */
-        ALTERNATIVE("bl check_pending_vserror; cbnz x0, 1f",
-                    "nop; nop",
-                    SKIP_SYNCHRONIZE_SERROR_ENTRY_EXIT)
+        alternative_if SKIP_SYNCHRONIZE_SERROR_ENTRY_EXIT
+        bl      check_pending_vserror
+        cbnz    x0, 1f
+        alternative_else_nop_endif
+
         mov     x0, sp
         bl      enter_hypervisor_from_guest_noirq
         msr     daifclr, \iflags
-- 
2.11.0


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