[Xen-devel] [PATCH v3 4/7] add nspin_sleep function to time manager

[Paul Semel <semelpaul@xxxxxxxxx>]

From: Paul Semel <phentex@xxxxxxxxx>

this function spin sleeps for t nanoseconds

Signed-off-by: Paul Semel <phentex@xxxxxxxxx>
---
 common/time.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/common/time.c b/common/time.c
index d0c9ed2..4770b9a 100644
--- a/common/time.c
+++ b/common/time.c
@@ -139,6 +139,18 @@ int gettimeofday(struct timeval *tp, void *restrict tzp)
     return 0;
 }
 
+static inline void nspin_sleep(uint64_t t)
+{
+    uint64_t curr = since_boot_time();
+    uint64_t end = curr + t;
+
+    if ( end < curr )
+        panic("end value overflows counter\n");
+
+    while ( since_boot_time() < end )
+        asm volatile ("pause");
+}
+
 /*
  * Local variables:
  * mode: C
-- 
2.16.1


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