[Xen-devel] [PRE-4.12 PATCH] xen/arm: time: cycles_t should be an uint64_t and not unsigned long

[Julien Grall <julien.grall@xxxxxxx>]

Since commit ca73ac8e7d "xen/arm: Add an isb() before reading CNTPCT_EL0
to prevent re-ordering", get_cycles() is now returning the number of
cycles and used in more callers.

While the counter registers is always 64-bit, get_cycles() will only
reutrn a 32-bit on Arm32 and therefore truncate the value. This will
result to weird behavior by both Xen and the Guest as the timer will not
be setup correctly.

This could be resolved by switch cycles_t from unsigned long to
unsigned int.

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

---
    This is only targeting xen 4.11 and earlier. Xen 4.12 and later have
    a correct definition of cycles_t thanks to da3d55ae67 "console:
    avoid printing no or null time stamps".

    This will hopefully unblock osstest on staging-4.10 and
    staging-4.11. This patch should be backported up to Xen 4.8.
---
 xen/include/asm-arm/time.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/xen/include/asm-arm/time.h b/xen/include/asm-arm/time.h
index ca30406669..bd7dc86d78 100644
--- a/xen/include/asm-arm/time.h
+++ b/xen/include/asm-arm/time.h
@@ -7,7 +7,7 @@
     DT_MATCH_COMPATIBLE("arm,armv7-timer"), \
     DT_MATCH_COMPATIBLE("arm,armv8-timer")
 
-typedef unsigned long cycles_t;
+typedef uint64_t cycles_t;
 
 static inline cycles_t get_cycles (void)
 {
-- 
2.11.0


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