[xen staging] x86/vRTC: use available macros for BCD <-> BIN conversion

[patchbot@xxxxxxx]

commit c780db53fa9451d05001360ca8c7aa8303893b05
Author:     Jan Beulich <jbeulich@xxxxxxxx>
AuthorDate: Tue Jun 30 09:39:45 2026 +0200
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Tue Jun 30 09:39:45 2026 +0200

    x86/vRTC: use available macros for BCD <-> BIN conversion
    
    There's no need to open-code these. No functional change intended, even if
    the | changes to + in to_bcd().
    
    Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
    Acked-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
---
 xen/arch/x86/hvm/rtc.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/xen/arch/x86/hvm/rtc.c b/xen/arch/x86/hvm/rtc.c
index e33a8ec108..4ba5881b24 100644
--- a/xen/arch/x86/hvm/rtc.c
+++ b/xen/arch/x86/hvm/rtc.c
@@ -247,18 +247,18 @@ static void cf_check rtc_update_timer2(void *opaque)
 
 static unsigned int to_bcd(const RTCState *s, unsigned int a)
 {
-    if ( s->hw.cmos_data[RTC_REG_B] & RTC_DM_BINARY )
-        return a;
+    if ( !(s->hw.cmos_data[RTC_REG_B] & RTC_DM_BINARY) )
+        BIN_TO_BCD(a);
 
-    return ((a / 10) << 4) | (a % 10);
+    return a;
 }
 
 static unsigned int from_bcd(const RTCState *s, unsigned int a)
 {
-    if ( s->hw.cmos_data[RTC_REG_B] & RTC_DM_BINARY )
-        return a;
+    if ( !(s->hw.cmos_data[RTC_REG_B] & RTC_DM_BINARY) )
+        BCD_TO_BIN(a);
 
-    return ((a >> 4) * 10) + (a & 0x0f);
+    return a;
 }
 
 /*
--
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