[PATCH 1/5] xen: Fix endian handling in muldiv64.c

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

WORDS_BIGENDIAN is a QEMU-ism.  In the very dim and distant past, we had a
fork of QEMU living in xen.git which wired WORDS_BIGENDIAN in the userspace
part of the build, but nothing ever wired it up in the hypervisor build.

Fixes: 86d5da49a6f7 ("[HVM] Support multiple HVM time device models coming 
soon.")
Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
CC: Jan Beulich <JBeulich@xxxxxxxx>
CC: Roger Pau Monné <roger.pau@xxxxxxxxxx>
CC: Stefano Stabellini <sstabellini@xxxxxxxxxx>
CC: Julien Grall <julien@xxxxxxx>
CC: Volodymyr Babchuk <Volodymyr_Babchuk@xxxxxxxx>
CC: Bertrand Marquis <bertrand.marquis@xxxxxxx>
CC: Michal Orzel <michal.orzel@xxxxxxx>
CC: Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>

I'm not sure that this wants backporting, seeing as we have no big-endian
architectures at all.  Otherwse, 4.20 and older can't rely on the existence of
__LITTLE_ENDIAN on older toolchains.
---
 xen/lib/muldiv64.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/xen/lib/muldiv64.c b/xen/lib/muldiv64.c
index 79411f5d59ea..f281578c09a4 100644
--- a/xen/lib/muldiv64.c
+++ b/xen/lib/muldiv64.c
@@ -13,10 +13,12 @@ uint64_t muldiv64(uint64_t a, uint32_t b, uint32_t c)
     union {
         uint64_t ll;
         struct {
-#ifdef WORDS_BIGENDIAN
+#if defined(__BIG_ENDIAN)
             uint32_t high, low;
-#else
+#elif defined(__LITTLE_ENDIAN)
             uint32_t low, high;
+#else
+# error Unknown Endianness
 #endif
         } l;
     } u, res;
-- 
2.39.5